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Ma Z, Sharma R, Rogers AN. Physiological Consequences of Nonsense-Mediated Decay and Its Role in Adaptive Responses. Biomedicines 2024; 12:1110. [PMID: 38791071 PMCID: PMC11117581 DOI: 10.3390/biomedicines12051110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 04/30/2024] [Accepted: 05/13/2024] [Indexed: 05/26/2024] Open
Abstract
The evolutionarily conserved nonsense-mediated mRNA decay (NMD) pathway is a quality control mechanism that degrades aberrant mRNA containing one or more premature termination codons (PTCs). Recent discoveries indicate that NMD also differentially regulates mRNA from wild-type protein-coding genes despite lacking PTCs. Together with studies showing that NMD is involved in development and adaptive responses that influence health and longevity, these findings point to an expanded role of NMD that adds a new layer of complexity in the post-transcriptional regulation of gene expression. However, the extent of its control, whether different types of NMD play different roles, and the resulting physiological outcomes remain unclear and need further elucidation. Here, we review different branches of NMD and what is known of the physiological outcomes associated with this type of regulation. We identify significant gaps in the understanding of this process and the utility of genetic tools in accelerating progress in this area.
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Affiliation(s)
- Zhengxin Ma
- MDI Biological Laboratory, Bar Harbor, ME 04609, USA
| | - Ratna Sharma
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA;
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2
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Harms FL, Dingemans AJM, Hempel M, Pfundt R, Bierhals T, Casar C, Müller C, Niermeijer JMF, Fischer J, Jahn A, Hübner C, Majore S, Agolini E, Novelli A, van der Smagt J, Ernst R, van Binsbergen E, Mancini GMS, van Slegtenhorst M, Barakat TS, Wakeling EL, Kamath A, Downie L, Pais L, White SM, de Vries BBA, Kutsche K. De novo PHF5A variants are associated with craniofacial abnormalities, developmental delay, and hypospadias. Genet Med 2023; 25:100927. [PMID: 37422718 DOI: 10.1016/j.gim.2023.100927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 06/30/2023] [Accepted: 07/02/2023] [Indexed: 07/10/2023] Open
Abstract
PURPOSE The SF3B splicing complex is composed of SF3B1-6 and PHF5A. We report a developmental disorder caused by de novo variants in PHF5A. METHODS Clinical, genomic, and functional studies using subject-derived fibroblasts and a heterologous cellular system were performed. RESULTS We studied 9 subjects with congenital malformations, including preauricular tags and hypospadias, growth abnormalities, and developmental delay who had de novo heterozygous PHF5A variants, including 4 loss-of-function (LOF), 3 missense, 1 splice, and 1 start-loss variant. In subject-derived fibroblasts with PHF5A LOF variants, wild-type and variant PHF5A mRNAs had a 1:1 ratio, and PHF5A mRNA levels were normal. Transcriptome sequencing revealed alternative promoter use and downregulated genes involved in cell-cycle regulation. Subject and control fibroblasts had similar amounts of PHF5A with the predicted wild-type molecular weight and of SF3B1-3 and SF3B6. SF3B complex formation was unaffected in 2 subject cell lines. CONCLUSION Our data suggest the existence of feedback mechanisms in fibroblasts with PHF5A LOF variants to maintain normal levels of SF3B components. These compensatory mechanisms in subject fibroblasts with PHF5A or SF3B4 LOF variants suggest disturbed autoregulation of mutated splicing factor genes in specific cell types, that is, neural crest cells, during embryonic development rather than haploinsufficiency as pathomechanism.
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Affiliation(s)
- Frederike L Harms
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alexander J M Dingemans
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maja Hempel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Institute of Human Genetics, University Hospital Heidelberg, Heidelberg, Germany
| | - Rolph Pfundt
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tatjana Bierhals
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Casar
- Bioinformatics Core, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Müller
- Bioinformatics Core, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Jan Fischer
- Institute for Clinical Genetics, University Hospital Carl Gustav Carus at the Technische Universität Dresden, Dresden, Germany
| | - Arne Jahn
- Institute for Clinical Genetics, University Hospital Carl Gustav Carus at the Technische Universität Dresden, Dresden, Germany
| | - Christoph Hübner
- Department of Neuropaediatrics, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Silvia Majore
- Division of Medical Genetics, Department of Experimental Medicine, San Camillo-Forlanini Hospital, Sapienza University, Rome, Italy
| | - Emanuele Agolini
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Antonio Novelli
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Jasper van der Smagt
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Robert Ernst
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Ellen van Binsbergen
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Grazia M S Mancini
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Marjon van Slegtenhorst
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Tahsin Stefan Barakat
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands; Discovery Unit, Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Emma L Wakeling
- North East Thames Regional Genetic Service, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, United Kingdom
| | - Arveen Kamath
- All Wales Medical Genomics Service/ Pennaeth Labordy Genomeg Cymru Gyfan, University Hospital of Wales, Heath Park, Cardiff, United Kingdom
| | - Lilian Downie
- Victorian Clinical Genetics Service, Murdoch Children's Research Institute, VIC; Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Lynn Pais
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA
| | - Susan M White
- Victorian Clinical Genetics Service, Murdoch Children's Research Institute, VIC; Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Bert B A de Vries
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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3
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Yuan L, Cheng F, Wu Z, Li X, Shen W. Homeobox B9 Promotes Colon Cancer Progression by Targeting SRSF3. Dig Dis Sci 2023; 68:3324-3340. [PMID: 37258980 DOI: 10.1007/s10620-023-07977-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 05/15/2023] [Indexed: 06/02/2023]
Abstract
BACKGROUND Homeobox B9 (HOXB9) is one of the HOX family of transcription factors that are essential for cancer development and embryonic growth. However, the clinical importance and biological involvement of HOXB9 in colon cancer (CC) are not adequately understood. AIMS To investigate whether HOXB9 participates in the proliferation, invasion, and migration of CC. METHODS This study investigated the function and clinical significance of HOXB9 mRNA and protein expression in CC. Furthermore, overexpression and knockdown experiments of HOXB9 were developed to explore their effects on CC cell transwell and proliferation. Moreover, a molecular mechanism of HOXB9 regulate serine/arginine-rich splicing factor 3 (SRSF3) was explored. RESULTS HOXB9 expression was higher in CC cells and tissues at both the mRNA and protein levels. Poor survival in CC patients was significantly connected with high HOXB9 expression, which was also strongly associated with the TNM stage and lymph node metastases. Furthermore, in vitro CC cell proliferation, transwell were markedly aided by HOXB9 overexpression. Contrarily, HOXB9 knockdown had the reverse result and inhibited the formation of xenograft tumors in naked mice. Gene set enrichment analysis (GSEA) revealed a correlation between high HOXB9 expression and spliceosomes. JASPAR and GEPIA2.0, in addition to CHIP and dual-luciferase reporting assays, confirmed that HOXB9 targets the promoter of SRSF3 to enhance its expression. We also found that SRSF3 knockdown eliminated HOXB9 from cell proliferation and transwell. CONCLUSION We characterized the function and mechanism of HOXB9 in regulating colon cancer growth, suggesting a novel molecular approach for colon cancer-targeted therapy.
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Affiliation(s)
- Lebin Yuan
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, People's Republic of China
| | - Fei Cheng
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, People's Republic of China
| | - Zhao Wu
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, People's Republic of China
| | - Xiaodong Li
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, People's Republic of China
| | - Wei Shen
- Department of General Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi, People's Republic of China.
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Jia R, Zheng ZM. Oncogenic SRSF3 in health and diseases. Int J Biol Sci 2023; 19:3057-3076. [PMID: 37416784 PMCID: PMC10321290 DOI: 10.7150/ijbs.83368] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 05/30/2023] [Indexed: 07/08/2023] Open
Abstract
Serine/arginine rich splicing factor 3 (SRSF3) is an important multi-functional splicing factor, and has attracted increasing attentions in the past thirty years. The importance of SRSF3 is evidenced by its impressively conserved protein sequences in all animals and alternative exon 4 which represents an autoregulatory mechanism to maintain its proper cellular expression level. New functions of SRSF3 have been continuously discovered recently, especially its oncogenic function. SRSF3 plays essential roles in many cellular processes by regulating almost all aspects of RNA biogenesis and processing of many target genes, and thus, contributes to tumorigenesis when overexpressed or disregulated. This review updates and highlights the gene, mRNA, and protein structure of SRSF3, the regulatory mechanisms of SRSF3 expression, and the characteristics of SRSF3 targets and binding sequences that contribute to SRSF3's diverse molecular and cellular functions in tumorigenesis and human diseases.
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Affiliation(s)
- Rong Jia
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, Hubei, China
| | - Zhi-Ming Zheng
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
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Li Y, Wang T, Liao Q, Luo X, Wang X, Zeng S, You M, Chen Y, Ruan XZ. Loss of Splicing Factor SRSF3 Impairs Lipophagy Through Ubiquitination and Degradation of Syntaxin17 in Hepatocytes. J Lipid Res 2023; 64:100342. [PMID: 36764525 PMCID: PMC10020108 DOI: 10.1016/j.jlr.2023.100342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 02/10/2023] Open
Abstract
Lipid accumulation in hepatocytes is the distinctive characteristic of nonalcoholic fatty liver disease. Serine/arginine-rich splicing factor 3 (SRSF3) is highly expressed in the liver and expression decreases in high-fat conditions. However, the role of SRSF3 in hepatic lipid metabolism needs to be clarified. Here, we showed that loss of SRSF3 was associated with lipid accumulation. We determined that SRSF3 regulated lipophagy, the process of selective degradation of lipid droplets by autophagy. Mechanistically, loss of SRSF3 impaired the fusion of the autophagosome and lysosome by promoting the proteasomal degradation of syntaxin 17 (STX17), a key autophagosomal SNARE protein. We found that ubiquitination of STX17 was increased and upregulation of seven in absentia homolog 1 was responsible for the increased posttranslational modification of STX17. Taken together, our data primarily demonstrate that loss of SRSF3 weakens the clearance of fatty acids by impairing lipophagy in the progression of nonalcoholic fatty liver disease, indicating a novel potential therapeutic target for fatty liver disease treatment.
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Affiliation(s)
- Yun Li
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Tao Wang
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Qiumin Liao
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Xiaoting Luo
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Xing Wang
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Shu Zeng
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Mengyue You
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Yaxi Chen
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China.
| | - Xiong Z Ruan
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China; John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, University College London, London, United Kingdom.
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6
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Ivanova OM, Anufrieva KS, Kazakova AN, Malyants IK, Shnaider PV, Lukina MM, Shender VO. Non-canonical functions of spliceosome components in cancer progression. Cell Death Dis 2023; 14:77. [PMID: 36732501 PMCID: PMC9895063 DOI: 10.1038/s41419-022-05470-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 11/23/2022] [Accepted: 11/25/2022] [Indexed: 02/04/2023]
Abstract
Dysregulation of pre-mRNA splicing is a common hallmark of cancer cells and it is associated with altered expression, localization, and mutations of the components of the splicing machinery. In the last few years, it has been elucidated that spliceosome components can also influence cellular processes in a splicing-independent manner. Here, we analyze open source data to understand the effect of the knockdown of splicing factors in human cells on the expression and splicing of genes relevant to cell proliferation, migration, cell cycle regulation, DNA repair, and cell death. We supplement this information with a comprehensive literature review of non-canonical functions of splicing factors linked to cancer progression. We also specifically discuss the involvement of splicing factors in intercellular communication and known autoregulatory mechanisms in restoring their levels in cells. Finally, we discuss strategies to target components of the spliceosome machinery that are promising for anticancer therapy. Altogether, this review greatly expands understanding of the role of spliceosome proteins in cancer progression.
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Affiliation(s)
- Olga M Ivanova
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russian Federation.
- Federal Research and Clinical Center of Physical-Chemical Medicine of the Federal Medical and Biological Agency, Moscow, 119435, Russian Federation.
- Institute for Regenerative Medicine, Sechenov University, Moscow, 119991, Russian Federation.
| | - Ksenia S Anufrieva
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russian Federation
- Federal Research and Clinical Center of Physical-Chemical Medicine of the Federal Medical and Biological Agency, Moscow, 119435, Russian Federation
| | - Anastasia N Kazakova
- Federal Research and Clinical Center of Physical-Chemical Medicine of the Federal Medical and Biological Agency, Moscow, 119435, Russian Federation
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, 141701, Russian Federation
| | - Irina K Malyants
- Federal Research and Clinical Center of Physical-Chemical Medicine of the Federal Medical and Biological Agency, Moscow, 119435, Russian Federation
- Faculty of Chemical-Pharmaceutical Technologies and Biomedical Drugs, Mendeleev University of Chemical Technology of Russia, Moscow, 125047, Russian Federation
| | - Polina V Shnaider
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russian Federation
- Federal Research and Clinical Center of Physical-Chemical Medicine of the Federal Medical and Biological Agency, Moscow, 119435, Russian Federation
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russian Federation
| | - Maria M Lukina
- Federal Research and Clinical Center of Physical-Chemical Medicine of the Federal Medical and Biological Agency, Moscow, 119435, Russian Federation
| | - Victoria O Shender
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russian Federation.
- Federal Research and Clinical Center of Physical-Chemical Medicine of the Federal Medical and Biological Agency, Moscow, 119435, Russian Federation.
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997, Russian Federation.
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7
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Che Y, Bai M, Lu K, Fu L. Splicing factor SRSF3 promotes the progression of cervical cancer through regulating DDX5. Mol Carcinog 2023; 62:210-223. [PMID: 36282044 DOI: 10.1002/mc.23477] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 09/07/2022] [Accepted: 09/22/2022] [Indexed: 01/25/2023]
Abstract
Aberrant alternative splicing (AS) profoundly affects tumorigenesis and cancer progression. Serine/arginine-rich splicing factor 3 (SRSF3) regulates the AS of precursor mRNAs and acts as a proto-oncogene in many tumors, but its function and potential mechanisms in cervical cancer remain unclear. Here, we found that SRSF3 was highly expressed in cervical cancer tissues and that SRSF3 expression was correlated with prognosis after analyses of the The Cancer Genome Atlas and GEO databases. Furthermore, knockdown of SRSF3 reduced the proliferation, migration, and invasion abilities of HeLa cells, while overexpression of SRSF3 promoted proliferation, migration, and invasion of CaSki cells. Further studies showed that SRSF3 mediated the variable splicing of exon 12 of the transcriptional cofactor DEAD-box helicase 5 (DDX5). Specifically, overexpression of SRSF3 promoted the production of the pro-oncogenic spliceosome DDX5-L and repressed the production of the repressive spliceosome DDX5-S. Ultimately, both SRSF3 and DDX5-L were able to upregulate oncogenic AKT expression, while DDX5-S downregulated AKT expression. In conclusion, we found that SRSF3 increased the production of DDX5-L and decreased the production of DDX5-S by regulating the variable splicing of DDX5. This, in turn promoted the proliferation, migration, and invasion of cervical cancer by upregulating the expression level of AKT. These results reveal the oncogenic role of SRSF3 in cervical cancer and emphasize the importance of the SRSF3-DDX5-AKT axis in tumorigenesis. SRSF3 and DDX5 are new potential biomarkers and therapeutic targets for cervical cancer.
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Affiliation(s)
- Yingying Che
- School of Basic Medicine, Qingdao University, Qingdao, China.,Weihai Ocean Vocational College, Weihai, China
| | - Mixue Bai
- School of Basic Medicine, Qingdao University, Qingdao, China
| | - Kun Lu
- School of Basic Medicine, Qingdao University, Qingdao, China
| | - Lin Fu
- School of Basic Medicine, Qingdao University, Qingdao, China
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8
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Nonsense-Mediated mRNA Decay as a Mediator of Tumorigenesis. Genes (Basel) 2023; 14:genes14020357. [PMID: 36833284 PMCID: PMC9956241 DOI: 10.3390/genes14020357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/23/2023] [Accepted: 01/26/2023] [Indexed: 02/03/2023] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is an evolutionarily conserved and well-characterized biological mechanism that ensures the fidelity and regulation of gene expression. Initially, NMD was described as a cellular surveillance or quality control process to promote selective recognition and rapid degradation of erroneous transcripts harboring a premature translation-termination codon (PTC). As estimated, one-third of mutated and disease-causing mRNAs were reported to be targeted and degraded by NMD, suggesting the significance of this intricate mechanism in maintaining cellular integrity. It was later revealed that NMD also elicits down-regulation of many endogenous mRNAs without mutations (~10% of the human transcriptome). Therefore, NMD modulates gene expression to evade the generation of aberrant truncated proteins with detrimental functions, compromised activities, or dominant-negative effects, as well as by controlling the abundance of endogenous mRNAs. By regulating gene expression, NMD promotes diverse biological functions during development and differentiation, and facilitates cellular responses to adaptation, physiological changes, stresses, environmental insults, etc. Mutations or alterations (such as abnormal expression, degradation, post-translational modification, etc.) that impair the function or expression of proteins associated with the NMD pathway can be deleterious to cells and may cause pathological consequences, as implicated in developmental and intellectual disabilities, genetic defects, and cancer. Growing evidence in past decades has highlighted NMD as a critical driver of tumorigenesis. Advances in sequencing technologies provided the opportunity to identify many NMD substrate mRNAs in tumor samples compared to matched normal tissues. Interestingly, many of these changes are tumor-specific and are often fine-tuned in a tumor-specific manner, suggesting the complex regulation of NMD in cancer. Tumor cells differentially exploit NMD for survival benefits. Some tumors promote NMD to degrade a subset of mRNAs, such as those encoding tumor suppressors, stress response proteins, signaling proteins, RNA binding proteins, splicing factors, and immunogenic neoantigens. In contrast, some tumors suppress NMD to facilitate the expression of oncoproteins or other proteins beneficial for tumor growth and progression. In this review, we discuss how NMD is regulated as a critical mediator of oncogenesis to promote the development and progression of tumor cells. Understanding how NMD affects tumorigenesis differentially will pave the way for the development of more effective and less toxic, targeted therapeutic opportunities in the era of personalized medicine.
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Cooperative Binding of SRSF3 to Structured 3'ss-α Exon RNA during α Exon Inclusion in the ZO-1 mRNA. Curr Issues Mol Biol 2023; 45:593-603. [PMID: 36661525 PMCID: PMC9857539 DOI: 10.3390/cimb45010039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 12/28/2022] [Accepted: 01/03/2023] [Indexed: 01/11/2023] Open
Abstract
ZO-1α+ and ZO-1α- proteins are expressed in hermetic and leaky tight junctions, respectively. Two cis-acting distant exonic elements partly activate the 240 nucleotide-long α exon producing the ZO-1α+ isoform. However, the elements within and around the α exon and their respective factors involved in its splicing are unknown. To study the dynamic interaction between SRSF3 and its bioinformatically predicted target sites around the 3'ss upstream of the α exon during its activation, we performed EMSA, crosslinking, and in vivo splicing assays by ZO-1 minigene expression and siRNA-mediated silencing in transfected cells. Using V1 RNase, we probed the possible formation of a hairpin RNA structure between the intronic and proximal exonic SRSF3 binding sites. The hairpin sufficed for complex formations in the EMSA. The interaction of SRSF3 with the intronic site promoted the cooperative binding of SRSF3 to the exonic site. Finally, SRSF3 restored α exon activation in SRSF3 knockdown transfectants. Altogether, our results show that SRSF3-hairpin RNA interaction is crucial in the early recognition of 3'ss for α exon activation. It remains to be explored whether SRSF3 recruits or stabilizes the binding of other factors or brings separate splice sites into proximity.
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10
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Kumar D, Das M, Oberg A, Sahoo D, Wu P, Sauceda C, Jih L, Ellies LG, Langiewicz MT, Sen S, Webster NJG. Hepatocyte Deletion of IGF2 Prevents DNA Damage and Tumor Formation in Hepatocellular Carcinoma. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2105120. [PMID: 35615981 PMCID: PMC9313545 DOI: 10.1002/advs.202105120] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 03/18/2022] [Indexed: 05/12/2023]
Abstract
Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Serine-arginine rich splicing factor 3 (SRSF3) plays a critical role in hepatocyte function and its loss in mice promotes chronic liver damage and leads to HCC. Hepatocyte-specific SRSF3 knockout mice (SKO mice) also overexpress insulin-like growth factor 2 (IGF2). In the present study, double deletion of Igf2 and Srsf3 (DKO mice) prevents hepatic fibrosis and inflammation, and completely prevents tumor formation, and is associated with decreased proliferation, apoptosis and DNA damage, and restored DNA repair enzyme expression. This is confirmed in vitro, where IGF2 treatment of HepG2 hepatoma cells decreases DNA repair enzyme expression and causes DNA damage. Tumors from the SKO mice also show mutational signatures consistent with homologous recombination and mismatch repair defects. Analysis of frozen human samples shows that SRSF3 protein is decreased sixfold in HCC compared to normal liver tissue but SRSF3 mRNA is increased. Looking at public TCGA data, HCC patients having high SRSF3 mRNA expression show poor survival, as do patients with alterations in known SRSF3-dependent splicing events. The results indicate that IGF2 overexpression in conjunction with reduced SRSF3 splicing activity could be a major cause of DNA damage and driver of liver cancer.
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Affiliation(s)
- Deepak Kumar
- Research and Development ServiceVA San Diego Healthcare SystemSan DiegoCA92161USA
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Manasi Das
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Alexis Oberg
- Research and Development ServiceVA San Diego Healthcare SystemSan DiegoCA92161USA
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Debashis Sahoo
- Division of Genome Information Sciences, Department of PediatricsUniversity of California San DiegoLa JollaCA92093USA
| | - Panyisha Wu
- Research and Development ServiceVA San Diego Healthcare SystemSan DiegoCA92161USA
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Consuelo Sauceda
- Research and Development ServiceVA San Diego Healthcare SystemSan DiegoCA92161USA
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Lily Jih
- Research and Development ServiceVA San Diego Healthcare SystemSan DiegoCA92161USA
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Lesley G. Ellies
- Division of Cancer Biology Research, Department of PathologyUniversity of California San DiegoLa JollaCA92093USA
- Moores Cancer CenterUniversity of California San DiegoLa JollaCA92093USA
| | - Magda T. Langiewicz
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Supriya Sen
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Nicholas J. G. Webster
- Research and Development ServiceVA San Diego Healthcare SystemSan DiegoCA92161USA
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
- Moores Cancer CenterUniversity of California San DiegoLa JollaCA92093USA
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11
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Hernandez VA, Carvajal-Moreno J, Wang X, Pietrzak M, Yalowich JC, Elton TS. Use of CRISPR/Cas9 with homology-directed repair to silence the human topoisomerase IIα intron-19 5’ splice site: Generation of etoposide resistance in human leukemia K562 cells. PLoS One 2022; 17:e0265794. [PMID: 35617303 PMCID: PMC9135202 DOI: 10.1371/journal.pone.0265794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 05/06/2022] [Indexed: 11/19/2022] Open
Abstract
DNA Topoisomerase IIα (TOP2α/170) is an enzyme essential for proliferating cells. For rapidly multiplying malignancies, this has made TOP2α/170 an important target for etoposide and other clinically active anticancer drugs. Efficacy of these agents is often limited by chemoresistance related to alterations in TOP2α/170 expression levels. Our laboratory recently demonstrated reduced levels of TOP2α/170 and overexpression of a C-terminal truncated 90-kDa isoform, TOP2α/90, due to intronic polyadenylation (IPA; within intron 19) in an acquired etoposide-resistant K562 clonal cell line, K/VP.5. We previously reported that this isoform heterodimerized with TOP2α/170 and was a determinant of acquired resistance to etoposide. Optimization of the weak TOP2α exon 19/intron 19 5′ splice site in drug-resistant K/VP.5 cells by gene-editing restored TOP2α/170 levels, diminished TOP2α/90 expression, and circumvented drug resistance. Conversely, in the present study, silencing of the exon 19/intron 19 5′ splice site in parental K562 cells by CRISPR/Cas9 with homology-directed repair (HDR), and thereby forcing intron 19 retention, was used to induce resistance by disrupting normal RNA processing (i.e., gene knockout), and to further evaluate the role of TOP2α/170 and TOP2α/90 isoforms as resistance determinants. Gene-edited clones were identified by quantitative polymerase chain reaction (qPCR) and verified by Sanger sequencing. TOP2α/170 mRNA/protein expression levels were attenuated in the TOP2α gene-edited clones which resulted in resistance to etoposide as assessed by reduced etoposide-induced DNA damage (γH2AX, Comet assays) and growth inhibition. RNA-seq and qPCR studies suggested that intron 19 retention leads to decreased TOP2α/170 expression by degradation of the TOP2α edited mRNA transcripts. Forced expression of TOP2α/90 in the gene-edited K562 cells further decreased etoposide-induced DNA damage in support of a dominant negative role for this truncated isoform. Together results support the important role of both TOP2α/170 and TOP2α/90 as determinants of sensitivity/resistance to TOP2α-targeting agents.
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Affiliation(s)
- Victor A. Hernandez
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, United States of America
| | - Jessika Carvajal-Moreno
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, United States of America
| | - Xinyi Wang
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, United States of America
| | - Maciej Pietrzak
- Department of Biomedical Informatics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Jack C. Yalowich
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (JCY); (TSE)
| | - Terry S. Elton
- Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (JCY); (TSE)
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12
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Yu T, Cazares O, Tang AD, Kim HY, Wald T, Verma A, Liu Q, Barcellos-Hoff MH, Floor SN, Jung HS, Brooks AN, Klein OD. SRSF1 governs progenitor-specific alternative splicing to maintain adult epithelial tissue homeostasis and renewal. Dev Cell 2022; 57:624-637.e4. [PMID: 35202586 PMCID: PMC8974236 DOI: 10.1016/j.devcel.2022.01.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 11/04/2021] [Accepted: 01/18/2022] [Indexed: 12/30/2022]
Abstract
Alternative splicing generates distinct mRNA variants and is essential for development, homeostasis, and renewal. Proteins of the serine/arginine (SR)-rich splicing factor family are major splicing regulators that are broadly required for organ development as well as cell and organism viability. However, how these proteins support adult organ function remains largely unknown. Here, we used the continuously growing mouse incisor as a model to dissect the functions of the prototypical SR family protein SRSF1 during tissue homeostasis and renewal. We identified an SRSF1-governed alternative splicing network that is specifically required for dental proliferation and survival of progenitors but dispensable for the viability of differentiated cells. We also observed a similar progenitor-specific role of SRSF1 in the small intestinal epithelium, indicating a conserved function of SRSF1 across adult epithelial tissues. Thus, our findings define a regulatory mechanism by which SRSF1 specifically controls progenitor-specific alternative splicing events to support adult tissue homeostasis and renewal.
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Affiliation(s)
- Tingsheng Yu
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Oscar Cazares
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Alison D Tang
- Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Hyun-Yi Kim
- Division in Anatomy and Developmental Biology, Department of Oral Biology, Oral Science Research Center, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, Korea
| | - Tomas Wald
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Adya Verma
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Qi Liu
- Department of Radiation Oncology, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94115, USA
| | - Mary Helen Barcellos-Hoff
- Department of Radiation Oncology, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94115, USA
| | - Stephen N Floor
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Han-Sung Jung
- Division in Anatomy and Developmental Biology, Department of Oral Biology, Oral Science Research Center, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, Korea
| | - Angela N Brooks
- Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Ophir D Klein
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Pediatrics and Institute for Human Genetics, University of California, San Francisco, San Francisco, CA 94143, USA.
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13
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Heazlewood SY, Ahmad T, Mohenska M, Guo BB, Gangatirkar P, Josefsson EC, Ellis SL, Ratnadiwakara M, Cao H, Cao B, Heazlewood CK, Williams B, Fulton M, White JF, Ramialison M, Nilsson SK, Änkö ML. The RNA-binding protein SRSF3 has an essential role in megakaryocyte maturation and platelet production. Blood 2022; 139:1359-1373. [PMID: 34852174 PMCID: PMC8900270 DOI: 10.1182/blood.2021013826] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 11/06/2021] [Indexed: 11/20/2022] Open
Abstract
RNA processing is increasingly recognized as a critical control point in the regulation of different hematopoietic lineages including megakaryocytes responsible for the production of platelets. Platelets are anucleate cytoplasts that contain a rich repertoire of RNAs encoding proteins with essential platelet functions derived from the parent megakaryocyte. It is largely unknown how RNA binding proteins contribute to the development and functions of megakaryocytes and platelets. We show that serine-arginine-rich splicing factor 3 (SRSF3) is essential for megakaryocyte maturation and generation of functional platelets. Megakaryocyte-specific deletion of Srsf3 in mice led to macrothrombocytopenia characterized by megakaryocyte maturation arrest, dramatically reduced platelet counts, and abnormally large functionally compromised platelets. SRSF3 deficient megakaryocytes failed to reprogram their transcriptome during maturation and to load platelets with RNAs required for normal platelet function. SRSF3 depletion led to nuclear accumulation of megakaryocyte mRNAs, demonstrating that SRSF3 deploys similar RNA regulatory mechanisms in megakaryocytes as in other cell types. Our study further suggests that SRSF3 plays a role in sorting cytoplasmic megakaryocyte RNAs into platelets and demonstrates how SRSF3-mediated RNA processing forms a central part of megakaryocyte gene regulation. Understanding SRSF3 functions in megakaryocytes and platelets provides key insights into normal thrombopoiesis and platelet pathologies as SRSF3 RNA targets in megakaryocytes are associated with platelet diseases.
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Affiliation(s)
- Shen Y Heazlewood
- Biomedical Manufacturing CSIRO, VIC, Australia
- Australian Regenerative Medicine Institute, Monash University, VIC, Australia
| | - Tanveer Ahmad
- Biomedical Manufacturing CSIRO, VIC, Australia
- Australian Regenerative Medicine Institute, Monash University, VIC, Australia
| | - Monika Mohenska
- Australian Regenerative Medicine Institute, Monash University, VIC, Australia
| | - Belinda B Guo
- School of Biomedical Sciences, Pathology and Laboratory Science, University of Western Australia, WA, Australia
| | | | - Emma C Josefsson
- Walter and Eliza Hall Institute of Medical Research, VIC, Australia
- Department of Medical Biology, The University of Melbourne, VIC, Australia
| | - Sarah L Ellis
- Peter MacCallum Cancer Centre, and Sir Peter MacCallum Department of Oncology, University of Melbourne, VIC, Australia
- Olivia Newton-John Cancer Research Institute, Microscopy Facility and School of Cancer Medicine, La Trobe University, VIC, Australia
| | - Madara Ratnadiwakara
- Australian Regenerative Medicine Institute, Monash University, VIC, Australia
- Hudson Institute of Medical Research, VIC, Australia; and
- Department of Molecular and Translational Sciences, Monash University, VIC, Australia
| | - Huimin Cao
- Biomedical Manufacturing CSIRO, VIC, Australia
- Australian Regenerative Medicine Institute, Monash University, VIC, Australia
| | - Benjamin Cao
- Biomedical Manufacturing CSIRO, VIC, Australia
- Australian Regenerative Medicine Institute, Monash University, VIC, Australia
| | - Chad K Heazlewood
- Biomedical Manufacturing CSIRO, VIC, Australia
- Australian Regenerative Medicine Institute, Monash University, VIC, Australia
| | - Brenda Williams
- Biomedical Manufacturing CSIRO, VIC, Australia
- Australian Regenerative Medicine Institute, Monash University, VIC, Australia
| | - Madeline Fulton
- Biomedical Manufacturing CSIRO, VIC, Australia
- Australian Regenerative Medicine Institute, Monash University, VIC, Australia
| | | | - Mirana Ramialison
- Australian Regenerative Medicine Institute, Monash University, VIC, Australia
| | - Susan K Nilsson
- Biomedical Manufacturing CSIRO, VIC, Australia
- Australian Regenerative Medicine Institute, Monash University, VIC, Australia
| | - Minna-Liisa Änkö
- Australian Regenerative Medicine Institute, Monash University, VIC, Australia
- Hudson Institute of Medical Research, VIC, Australia; and
- Department of Molecular and Translational Sciences, Monash University, VIC, Australia
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14
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Xiong J, Chen Y, Wang W, Sun J. Biological function and molecular mechanism of SRSF3 in cancer and beyond. Oncol Lett 2021; 23:21. [PMID: 34858525 PMCID: PMC8617561 DOI: 10.3892/ol.2021.13139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 10/07/2021] [Indexed: 12/15/2022] Open
Abstract
Serine/arginine-rich splicing factor 3 (SRSF3; also known as SRp20), an important member of the family of SRSFs, is abnormally expressed in tumors, resulting in aberrant splicing of hub genes, such as CD44, HER2, MDM4, Rac family small GTPase 1 and tumor protein p53. Under normal conditions, the splicing and expression of SRSF3 are strictly regulated. However, the splicing, expression and phosphorylation of SRSF3 are abnormal in tumors. SRSF3 plays important roles in the occurrence and development of tumors, including the promotion of tumorigenesis, cellular proliferation, the cell cycle and metastasis, as well as inhibition of cell senescence, apoptosis and autophagy. SRSF3-knockdown significantly inhibits the proliferation and metastatic characteristics of tumor cells. Therefore, SRSF3 may be suggested as a novel anti-tumor target. The other biological functions of SRSF3 and its regulatory mechanisms are also summarized in the current review.
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Affiliation(s)
- Jian Xiong
- Institute of Medical Biotechnology, Suzhou Vocational Health College, Suzhou, Jiangsu 215009, P.R. China
| | - Yinshuang Chen
- Center for Drug Metabolism and Pharmacokinetics, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China
| | - Weipeng Wang
- Center for Drug Metabolism and Pharmacokinetics, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, P.R. China
| | - Jing Sun
- Institute of Medical Biotechnology, Suzhou Vocational Health College, Suzhou, Jiangsu 215009, P.R. China
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15
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Mehterov N, Kazakova M, Sbirkov Y, Vladimirov B, Belev N, Yaneva G, Todorova K, Hayrabedyan S, Sarafian V. Alternative RNA Splicing-The Trojan Horse of Cancer Cells in Chemotherapy. Genes (Basel) 2021; 12:genes12071085. [PMID: 34356101 PMCID: PMC8306420 DOI: 10.3390/genes12071085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 12/12/2022] Open
Abstract
Almost all transcribed human genes undergo alternative RNA splicing, which increases the diversity of the coding and non-coding cellular landscape. The resultant gene products might have distinctly different and, in some cases, even opposite functions. Therefore, the abnormal regulation of alternative splicing plays a crucial role in malignant transformation, development, and progression, a fact supported by the distinct splicing profiles identified in both healthy and tumor cells. Drug resistance, resulting in treatment failure, still remains a major challenge for current cancer therapy. Furthermore, tumor cells often take advantage of aberrant RNA splicing to overcome the toxicity of the administered chemotherapeutic agents. Thus, deciphering the alternative RNA splicing variants in tumor cells would provide opportunities for designing novel therapeutics combating cancer more efficiently. In the present review, we provide a comprehensive outline of the recent findings in alternative splicing in the most common neoplasms, including lung, breast, prostate, head and neck, glioma, colon, and blood malignancies. Molecular mechanisms developed by cancer cells to promote oncogenesis as well as to evade anticancer drug treatment and the subsequent chemotherapy failure are also discussed. Taken together, these findings offer novel opportunities for future studies and the development of targeted therapy for cancer-specific splicing variants.
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Affiliation(s)
- Nikolay Mehterov
- Department of Medical Biology, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria; (N.M.); (M.K.); (Y.S.)
- Research Institute, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria
| | - Maria Kazakova
- Department of Medical Biology, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria; (N.M.); (M.K.); (Y.S.)
- Research Institute, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria
| | - Yordan Sbirkov
- Department of Medical Biology, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria; (N.M.); (M.K.); (Y.S.)
- Research Institute, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria
| | - Boyan Vladimirov
- Department of Maxillofacial Surgery, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria;
| | - Nikolay Belev
- Medical Simulation and Training Center, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria;
| | - Galina Yaneva
- Department of Biology, Faculty of Pharmacy, Medical University of Varna, 9002 Varna, Bulgaria;
| | - Krassimira Todorova
- Laboratory of Reproductive OMICs Technologies, Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (K.T.); (S.H.)
| | - Soren Hayrabedyan
- Laboratory of Reproductive OMICs Technologies, Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (K.T.); (S.H.)
| | - Victoria Sarafian
- Department of Medical Biology, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria; (N.M.); (M.K.); (Y.S.)
- Research Institute, Medical University-Plovdiv, 4002 Plovdiv, Bulgaria
- Correspondence: ; Tel.: +359-882-512-952
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16
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Yang H, Beutler B, Zhang D. Emerging roles of spliceosome in cancer and immunity. Protein Cell 2021; 13:559-579. [PMID: 34196950 PMCID: PMC9232692 DOI: 10.1007/s13238-021-00856-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 05/08/2021] [Indexed: 12/19/2022] Open
Abstract
Precursor messenger RNA (pre-mRNA) splicing is catalyzed by an intricate ribonucleoprotein complex called the spliceosome. Although the spliceosome is considered to be general cell “housekeeping” machinery, mutations in core components of the spliceosome frequently correlate with cell- or tissue-specific phenotypes and diseases. In this review, we expound the links between spliceosome mutations, aberrant splicing, and human cancers. Remarkably, spliceosome-targeted therapies (STTs) have become efficient anti-cancer strategies for cancer patients with splicing defects. We also highlight the links between spliceosome and immune signaling. Recent studies have shown that some spliceosome gene mutations can result in immune dysregulation and notable phenotypes due to mis-splicing of immune-related genes. Furthermore, several core spliceosome components harbor splicing-independent immune functions within the cell, expanding the functional repertoire of these diverse proteins.
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Affiliation(s)
- Hui Yang
- Department of Neurosurgery, Huashan Hospital, Shanghai Key laboratory of Brain Function Restoration and Neural Regeneration, MOE Frontiers Center for Brain Science, Institute for Translational Brain Research, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Bruce Beutler
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
| | - Duanwu Zhang
- Children's Hospital of Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China.
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17
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Watabe E, Togo-Ohno M, Ishigami Y, Wani S, Hirota K, Kimura-Asami M, Hasan S, Takei S, Fukamizu A, Suzuki Y, Suzuki T, Kuroyanagi H. m 6 A-mediated alternative splicing coupled with nonsense-mediated mRNA decay regulates SAM synthetase homeostasis. EMBO J 2021; 40:e106434. [PMID: 34152017 DOI: 10.15252/embj.2020106434] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 04/29/2021] [Accepted: 05/07/2021] [Indexed: 12/24/2022] Open
Abstract
Alternative splicing of pre-mRNAs can regulate gene expression levels by coupling with nonsense-mediated mRNA decay (NMD). In order to elucidate a repertoire of mRNAs regulated by alternative splicing coupled with NMD (AS-NMD) in an organism, we performed long-read RNA sequencing of poly(A)+ RNAs from an NMD-deficient mutant strain of Caenorhabditis elegans, and obtained full-length sequences for mRNA isoforms from 259 high-confidence AS-NMD genes. Among them are the S-adenosyl-L-methionine (SAM) synthetase (sams) genes sams-3 and sams-4. SAM synthetase activity autoregulates sams gene expression through AS-NMD in a negative feedback loop. We furthermore find that METT-10, the orthologue of human U6 snRNA methyltransferase METTL16, is required for the splicing regulation in␣vivo, and specifically methylates the invariant AG dinucleotide at the distal 3' splice site (3'SS) in␣vitro. Direct RNA sequencing coupled with machine learning confirms m6 A modification of endogenous sams mRNAs. Overall, these results indicate that homeostasis of SAM synthetase in C. elegans is maintained by alternative splicing regulation through m6 A modification at the 3'SS of the sams genes.
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Affiliation(s)
- Eichi Watabe
- Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Tokyo, Japan
| | - Marina Togo-Ohno
- Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Tokyo, Japan
| | - Yuma Ishigami
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Shotaro Wani
- Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Tokyo, Japan
| | - Keiko Hirota
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba-shi, Ibaraki, Japan
| | - Mariko Kimura-Asami
- Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Tokyo, Japan
| | - Sharmin Hasan
- Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Tokyo, Japan
| | - Satomi Takei
- Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Tokyo, Japan
| | - Akiyoshi Fukamizu
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba-shi, Ibaraki, Japan
| | - Yutaka Suzuki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa-shi, Chiba, Japan
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Hidehito Kuroyanagi
- Laboratory of Gene Expression, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Tokyo, Japan.,Department of Biochemistry, Graduate School of Medicine, University of the Ryukyus, Nishihara-cho, Okinawa, Japan
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18
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Wang H, Jiang Y. SRp20: A potential therapeutic target for human tumors. Pathol Res Pract 2021; 224:153444. [PMID: 34126370 DOI: 10.1016/j.prp.2021.153444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 04/11/2021] [Accepted: 04/11/2021] [Indexed: 12/12/2022]
Abstract
As an important member of SR protein family, SRp20 plays a crucial role in alternative splicing. It not only participates in cell cycle regulation, export of mRNA, cleaving of primary microRNAs, homologous recombination-mediated DNA repair, cellular senescence and apoptosis, but also gets involved in the integrity and pluripotency of genome. Alternative splicing maintains a strict balance in the body to ensure the normal physiological function of cells. Once the balance is broken, diseases, even tumors, will follow. Through the analysis of SRp20-related articles, we found that Alzheimer's disease, glaucoma, bipolar disorder and other diseases have a certain relationship with SRp20. More importantly, SRp20 is closely related to the occurrence, proliferation, invasion and metastasis of various tumors, as well as chemotherapy resistance. Some SRp20 inhibitors have shown significant anticancer efficacy, suggesting a potential therapeutic strategy for tumors.
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Affiliation(s)
- Han Wang
- Department of Pathology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen, China
| | - Yanxia Jiang
- Department of Pathology, The Affiliated Hospital of Qingdao University, Qingdao, China.
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19
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The GAUGAA Motif Is Responsible for the Binding between circSMARCA5 and SRSF1 and Related Downstream Effects on Glioblastoma Multiforme Cell Migration and Angiogenic Potential. Int J Mol Sci 2021; 22:ijms22041678. [PMID: 33562358 PMCID: PMC7915938 DOI: 10.3390/ijms22041678] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/26/2021] [Accepted: 02/04/2021] [Indexed: 12/17/2022] Open
Abstract
Circular RNAs (circRNAs) are a large class of RNAs with regulatory functions within cells. We recently showed that circSMARCA5 is a tumor suppressor in glioblastoma multiforme (GBM) and acts as a decoy for Serine and Arginine Rich Splicing Factor 1 (SRSF1) through six predicted binding sites (BSs). Here we characterized RNA motifs functionally involved in the interaction between circSMARCA5 and SRSF1. Three different circSMARCA5 molecules (Mut1, Mut2, Mut3), each mutated in two predicted SRSF1 BSs at once, were obtained through PCR-based replacement of wild-type (WT) BS sequences and cloned in three independent pcDNA3 vectors. Mut1 significantly decreased its capability to interact with SRSF1 as compared to WT, based on the RNA immunoprecipitation assay. In silico analysis through the “Find Individual Motif Occurrences” (FIMO) algorithm showed GAUGAA as an experimentally validated SRSF1 binding motif significantly overrepresented within both predicted SRSF1 BSs mutated in Mut1 (q-value = 0.0011). U87MG and CAS-1, transfected with Mut1, significantly increased their migration with respect to controls transfected with WT, as revealed by the cell exclusion zone assay. Immortalized human brain microvascular endothelial cells (IM-HBMEC) exposed to conditioned medium (CM) harvested from U87MG and CAS-1 transfected with Mut1 significantly sprouted more than those treated with CM harvested from U87MG and CAS-1 transfected with WT, as shown by the tube formation assay. qRT-PCR showed that the intracellular pro- to anti-angiogenic Vascular Endothelial Growth Factor A (VEGFA) mRNA isoform ratio and the amount of total VEGFA mRNA secreted in CM significantly increased in Mut1-transfected CAS-1 as compared to controls transfected with WT. Our data suggest that GAUGAA is the RNA motif responsible for the interaction between circSMARCA5 and SRSF1 as well as for the circSMARCA5-mediated control of GBM cell migration and angiogenic potential.
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20
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García-Moreno JF, Romão L. Perspective in Alternative Splicing Coupled to Nonsense-Mediated mRNA Decay. Int J Mol Sci 2020; 21:ijms21249424. [PMID: 33321981 PMCID: PMC7764535 DOI: 10.3390/ijms21249424] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 12/19/2022] Open
Abstract
Alternative splicing (AS) of precursor mRNA (pre-mRNA) is a cellular post-transcriptional process that generates protein isoform diversity. Nonsense-mediated RNA decay (NMD) is an mRNA surveillance pathway that recognizes and selectively degrades transcripts containing premature translation-termination codons (PTCs), thereby preventing the production of truncated proteins. Nevertheless, NMD also fine-tunes the gene expression of physiological mRNAs encoding full-length proteins. Interestingly, around one third of all AS events results in PTC-containing transcripts that undergo NMD. Numerous studies have reported a coordinated action between AS and NMD, in order to regulate the expression of several genes, especially those coding for RNA-binding proteins (RBPs). This coupling of AS to NMD (AS-NMD) is considered a gene expression tool that controls the ratio of productive to unproductive mRNA isoforms, ultimately degrading PTC-containing non-functional mRNAs. In this review, we focus on the mechanisms underlying AS-NMD, and how this regulatory process is able to control the homeostatic expression of numerous RBPs, including splicing factors, through auto- and cross-regulatory feedback loops. Furthermore, we discuss the importance of AS-NMD in the regulation of biological processes, such as cell differentiation. Finally, we analyze interesting recent data on the relevance of AS-NMD to human health, covering its potential roles in cancer and other disorders.
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Affiliation(s)
- Juan F. García-Moreno
- Department of Human Genetics, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal;
- Faculty of Science, BioISI—Biosystems and Integrative Sciences Institute, University of Lisboa, 1749-016 Lisboa, Portugal
| | - Luísa Romão
- Department of Human Genetics, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal;
- Faculty of Science, BioISI—Biosystems and Integrative Sciences Institute, University of Lisboa, 1749-016 Lisboa, Portugal
- Correspondence: ; Tel.: +351-217-508-155
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21
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Leclair NK, Brugiolo M, Urbanski L, Lawson SC, Thakar K, Yurieva M, George J, Hinson JT, Cheng A, Graveley BR, Anczuków O. Poison Exon Splicing Regulates a Coordinated Network of SR Protein Expression during Differentiation and Tumorigenesis. Mol Cell 2020; 80:648-665.e9. [PMID: 33176162 PMCID: PMC7680420 DOI: 10.1016/j.molcel.2020.10.019] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 10/07/2020] [Accepted: 10/12/2020] [Indexed: 12/18/2022]
Abstract
The RNA isoform repertoire is regulated by splicing factor (SF) expression, and alterations in SF levels are associated with disease. SFs contain ultraconserved poison exon (PE) sequences that exhibit greater identity across species than nearby coding exons, but their physiological role and molecular regulation is incompletely understood. We show that PEs in serine-arginine-rich (SR) proteins, a family of 14 essential SFs, are differentially spliced during induced pluripotent stem cell (iPSC) differentiation and in tumors versus normal tissues. We uncover an extensive cross-regulatory network of SR proteins controlling their expression via alternative splicing coupled to nonsense-mediated decay. We define sequences that regulate PE inclusion and protein expression of the oncogenic SF TRA2β using an RNA-targeting CRISPR screen. We demonstrate location dependency of RS domain activity on regulation of TRA2β-PE using CRISPR artificial SFs. Finally, we develop splice-switching antisense oligonucleotides to reverse the increased skipping of TRA2β-PE detected in breast tumors, altering breast cancer cell viability, proliferation, and migration.
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Affiliation(s)
- Nathan K Leclair
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; Graduate Program in Genetics and Development, UConn Health, Farmington, CT, USA
| | - Mattia Brugiolo
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA
| | - Laura Urbanski
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; Graduate Program in Genetics and Development, UConn Health, Farmington, CT, USA
| | - Shane C Lawson
- Graduate Program in Genetics and Development, UConn Health, Farmington, CT, USA; Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, USA
| | - Ketan Thakar
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA
| | - Marina Yurieva
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA
| | - Joshy George
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; Institute for Systems Genomics, UConn Health, Farmington, CT, USA
| | - John Travis Hinson
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, USA
| | - Albert Cheng
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, USA; Institute for Systems Genomics, UConn Health, Farmington, CT, USA
| | - Brenton R Graveley
- Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, USA; Institute for Systems Genomics, UConn Health, Farmington, CT, USA
| | - Olga Anczuków
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, USA; Institute for Systems Genomics, UConn Health, Farmington, CT, USA.
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22
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SRSF3 Is a Critical Requirement for Inclusion of Exon 3 of BIS Pre-mRNA. Cells 2020; 9:cells9102325. [PMID: 33086735 PMCID: PMC7589869 DOI: 10.3390/cells9102325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/17/2020] [Accepted: 10/19/2020] [Indexed: 11/17/2022] Open
Abstract
BCL-2 interacting cell death suppressor (BIS), also known as BAG3, is a multifunctional protein. Aberrant expression and mutation of BIS have been implicated in cancers and myopathy. However, there have only been a few studies on the splicing of BIS pre-mRNA. In the present study, through RT-PCR and sequencing in various cell lines and mouse tissues, we identified for the first time the presence of BIS mRNA isomers in which exon 3 or exons 2–3 are skipped. We also demonstrated that the depletion of SRSF3 promoted the skipping of exon 3 of BIS pre-mRNA in endogenous BIS and the GFP-BIS minigene. SRSF3 specifically interacts with the putative binding sites in exon 3, in which deletion promoted the skipping of exon 3 in the GFP-BIS minigene, which was comparable to the effect of SRSF knockdown. Even though acceleration of exon 3 skipping was not observed in response to various stimuli, SRSF3 depletion, accompanied by the production of a truncated BIS protein, inhibited the nuclear translocation of HSF1, which was restored by the wild-type BIS, not by exon 3-depleted BIS. Therefore, our results suggested that the maintenance of SRSF3 levels and subsequent preservation of the intact BIS protein is an important factor in modulating HSF1 localization upon cellular stress.
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23
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Abstract
Genome-wide analysis of transcriptome data in Chlamydomonas reinhardtii shows periodic patterns in gene expression levels when cultures are grown under alternating light and dark cycles so that G1 of the cell cycle occurs in the light phase and S/M/G0 occurs during the dark phase. However, alternative splicing, a process that enables a greater protein diversity from a limited set of genes, remains largely unexplored by previous transcriptome based studies in C. reinhardtii. In this study, we used existing longitudinal RNA-seq data obtained during the light-dark cycle to investigate the changes in the alternative splicing pattern and found that 3277 genes (19.75% of 17,746 genes) undergo alternative splicing. These splicing events include Alternative 5′ (Alt 5′), Alternative 3′ (Alt 3′) and Exon skipping (ES) events that are referred as alternative site selection (ASS) events and Intron retention (IR) events. By clustering analysis, we identified a subset of events (26 ASS events and 10 IR events) that show periodic changes in the splicing pattern during the cell cycle. About two-thirds of these 36 genes either introduce a pre-termination codon (PTC) or introduce insertions or deletions into functional domains of the proteins, which implicate splicing in altering gene function. These findings suggest that alternative splicing is also regulated during the Chlamydomonas cell cycle, although not as extensively as changes in gene expression. The longitudinal changes in the alternative splicing pattern during the cell cycle captured by this study provides an important resource to investigate alternative splicing in genes of interest during the cell cycle in Chlamydomonas reinhardtii and other eukaryotes.
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24
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Zhou Z, Gong Q, Lin Z, Wang Y, Li M, Wang L, Ding H, Li P. Emerging Roles of SRSF3 as a Therapeutic Target for Cancer. Front Oncol 2020; 10:577636. [PMID: 33072610 PMCID: PMC7544984 DOI: 10.3389/fonc.2020.577636] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 08/28/2020] [Indexed: 12/14/2022] Open
Abstract
Ser/Arg-rich (SR) proteins are RNA-binding proteins known as constitutive and alternative splicing (AS) regulators that regulate multiple aspects of the gene expression program. Ser/Arg-rich splicing factor 3 (SRSF3) is the smallest member of the SR protein family, and its level is controlled by multiple factors and involves complex mechanisms in eukaryote cells, whereas the aberrant expression of SRSF3 is associated with many human diseases, including cancer. Here, we review state-of-the-art research on SRSF3 in terms of its function, expression, and misregulation in human cancers. We emphasize the negative consequences of the overexpression of the SRSF3 oncogene in cancers, the pathways underlying SRSF3-mediated transformation, and implications of potential anticancer drugs by downregulation of SRSF3 expression for cancer therapy. Cumulative research on SRSF3 provides critical insight into its essential part in maintaining cellular processes, offering potential new targets for anti-cancer therapy.
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Affiliation(s)
- Zhixia Zhou
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Qi Gong
- Departments of Pediatrics, Second Clinical Medical College of Qingdao University, Qingdao, China
| | - Zhijuan Lin
- Key Laboratory for Immunology in Universities of Shandong Province, School of Clinical Medicine, Weifang Medical University, Weifang, China
| | - Yin Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Mengkun Li
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Lu Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Hongfei Ding
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
| | - Peifeng Li
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao, China
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25
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Pararajalingam P, Coyle KM, Arthur SE, Thomas N, Alcaide M, Meissner B, Boyle M, Qureshi Q, Grande BM, Rushton C, Slack GW, Mungall AJ, Tam CS, Agarwal R, Dawson SJ, Lenz G, Balasubramanian S, Gascoyne RD, Steidl C, Connors J, Villa D, Audas TE, Marra MA, Johnson NA, Scott DW, Morin RD. Coding and noncoding drivers of mantle cell lymphoma identified through exome and genome sequencing. Blood 2020; 136:572-584. [PMID: 32160292 PMCID: PMC7440974 DOI: 10.1182/blood.2019002385] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 02/20/2020] [Indexed: 12/11/2022] Open
Abstract
Mantle cell lymphoma (MCL) is an uncommon B-cell non-Hodgkin lymphoma (NHL) that is incurable with standard therapies. The genetic drivers of this cancer have not been firmly established, and the features that contribute to differences in clinical course remain limited. To extend our understanding of the biological pathways involved in this malignancy, we performed a large-scale genomic analysis of MCL using data from 51 exomes and 34 genomes alongside previously published exome cohorts. To confirm our findings, we resequenced the genes identified in the exome cohort in 191 MCL tumors, each having clinical follow-up data. We confirmed the prognostic association of TP53 and NOTCH1 mutations. Our sequencing revealed novel recurrent noncoding mutations surrounding a single exon of the HNRNPH1gene. In RNA-seq data from 103 of these cases, MCL tumors with these mutations had a distinct imbalance of HNRNPH1 isoforms. This altered splicing of HNRNPH1 was associated with inferior outcomes in MCL and showed a significant increase in protein expression by immunohistochemistry. We describe a functional role for these recurrent noncoding mutations in disrupting an autoregulatory feedback mechanism, thereby deregulating HNRNPH1 protein expression. Taken together, these data strongly imply a role for aberrant regulation of messenger RNA processing in MCL pathobiology.
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Affiliation(s)
- Prasath Pararajalingam
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Krysta M Coyle
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Sarah E Arthur
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Nicole Thomas
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Miguel Alcaide
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Barbara Meissner
- BC Cancer Centre for Lymphoid Cancer and
- BC Cancer Research Centre, Vancouver, BC, Canada
| | - Merrill Boyle
- BC Cancer Centre for Lymphoid Cancer and
- BC Cancer Research Centre, Vancouver, BC, Canada
| | - Quratulain Qureshi
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Bruno M Grande
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Christopher Rushton
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Graham W Slack
- BC Cancer Centre for Lymphoid Cancer and
- BC Cancer Research Centre, Vancouver, BC, Canada
| | | | - Constantine S Tam
- Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
- University of Melbourne, Melbourne, VIC, Australia
| | - Rishu Agarwal
- Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Sarah-Jane Dawson
- Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
- University of Melbourne, Melbourne, VIC, Australia
| | - Georg Lenz
- Department of Medicine A, Hematology, Oncology, and Pneumology, University Hospital Münster, Münster, Germany
| | | | - Randy D Gascoyne
- BC Cancer Centre for Lymphoid Cancer and
- BC Cancer Research Centre, Vancouver, BC, Canada
| | - Christian Steidl
- BC Cancer Centre for Lymphoid Cancer and
- BC Cancer Research Centre, Vancouver, BC, Canada
| | - Joseph Connors
- BC Cancer Centre for Lymphoid Cancer and
- BC Cancer Research Centre, Vancouver, BC, Canada
| | - Diego Villa
- BC Cancer Centre for Lymphoid Cancer and
- BC Cancer Research Centre, Vancouver, BC, Canada
| | - Timothy E Audas
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Marco A Marra
- BC Cancer Centre for Lymphoid Cancer and
- BC Cancer Research Centre, Vancouver, BC, Canada
| | | | - David W Scott
- BC Cancer Centre for Lymphoid Cancer and
- BC Cancer Research Centre, Vancouver, BC, Canada
| | - Ryan D Morin
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Michael Smith Genome Sciences Centre, Vancouver, BC, Canada
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26
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Buccitelli C, Selbach M. mRNAs, proteins and the emerging principles of gene expression control. Nat Rev Genet 2020; 21:630-644. [PMID: 32709985 DOI: 10.1038/s41576-020-0258-4] [Citation(s) in RCA: 458] [Impact Index Per Article: 114.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2020] [Indexed: 12/15/2022]
Abstract
Gene expression involves transcription, translation and the turnover of mRNAs and proteins. The degree to which protein abundances scale with mRNA levels and the implications in cases where this dependency breaks down remain an intensely debated topic. Here we review recent mRNA-protein correlation studies in the light of the quantitative parameters of the gene expression pathway, contextual confounders and buffering mechanisms. Although protein and mRNA levels typically show reasonable correlation, we describe how transcriptomics and proteomics provide useful non-redundant readouts. Integrating both types of data can reveal exciting biology and is an essential step in refining our understanding of the principles of gene expression control.
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Affiliation(s)
| | - Matthias Selbach
- Proteome Dynamics, Max Delbrück Center for Molecular Medicine, Berlin, Germany. .,Charité - Universitätsmedizin Berlin, Berlin, Germany.
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27
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More DA, Kumar A. SRSF3: Newly discovered functions and roles in human health and diseases. Eur J Cell Biol 2020; 99:151099. [PMID: 32800280 DOI: 10.1016/j.ejcb.2020.151099] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/15/2020] [Accepted: 06/29/2020] [Indexed: 12/21/2022] Open
Abstract
The serine/arginine rich proteins (SR proteins) are members of a family of RNA binding proteins involved in regulating various features of RNA metabolism, including pre-mRNA constitutive and alternative splicing. In humans, a total of 12 SR splicing factors (SRSFs) namely SRSF1-SRSF12 have been reported. SRSF3, the smallest member of the SR family and the focus of this review, regulates critical steps in mRNA metabolism and has been shown to have mRNA-independent functions as well. Recent studies on SRSF3 have uncovered its role in a wide array of complex biological processes. We have also reviewed the involvement of SRSF3 in disease conditions like cancer, ageing, neurological and cardiac disorders. Finally, we have discussed in detail the autoregulation of SRSF3 and its implications in cancer and commented on the potential of SRSF3 as a therapeutic target, especially in the context of cancer.
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Affiliation(s)
- Dhanashree Anil More
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India
| | - Arun Kumar
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India.
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28
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Fujita KI, Ishizuka T, Mitsukawa M, Kurata M, Masuda S. Regulating Divergent Transcriptomes through mRNA Splicing and Its Modulation Using Various Small Compounds. Int J Mol Sci 2020; 21:ijms21062026. [PMID: 32188117 PMCID: PMC7139312 DOI: 10.3390/ijms21062026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/11/2020] [Accepted: 03/12/2020] [Indexed: 12/14/2022] Open
Abstract
Human transcriptomes are more divergent than genes and contribute to the sophistication of life. This divergence is derived from various isoforms arising from alternative splicing. In addition, alternative splicing regulated by spliceosomal factors and RNA structures, such as the RNA G-quadruplex, is important not only for isoform diversity but also for regulating gene expression. Therefore, abnormal splicing leads to serious diseases such as cancer and neurodegenerative disorders. In the first part of this review, we describe the regulation of divergent transcriptomes using alternative mRNA splicing. In the second part, we present the relationship between the disruption of splicing and diseases. Recently, various compounds with splicing inhibitor activity were established. These splicing inhibitors are recognized as a biological tool to investigate the molecular mechanism of splicing and as a potential therapeutic agent for cancer treatment. Food-derived compounds with similar functions were found and are expected to exhibit anticancer effects. In the final part, we describe the compounds that modulate the messenger RNA (mRNA) splicing process and their availability for basic research and future clinical potential.
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29
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Che Y, Fu L. Aberrant expression and regulatory network of splicing factor-SRSF3 in tumors. J Cancer 2020; 11:3502-3511. [PMID: 32284746 PMCID: PMC7150454 DOI: 10.7150/jca.42645] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 02/26/2020] [Indexed: 12/14/2022] Open
Abstract
Alternative splicing facilitates the splicing of precursor RNA into different isoforms. Alternatively spliced transcripts often exhibit antagonistic functions or differential temporal or spatial expression patterns. There is increasing evidence that alternative splicing, especially by the serine-arginine rich (SR) protein family, leads to abnormal expression patterns and is closely related to the development of cancer. SRSF3, also known as SRp20, is a splicing factor. Through alternative splicing, it plays important roles in regulating various biological functions, such as cell cycle, cell proliferation, migration and invasion, under pathological and physiological conditions. Deregulation of SRSF3 is an essential feature of cancers. SRSF3 is also considered a candidate therapeutic target. Therefore, the involvement of abnormal splicing in tumorigenesis and the regulation of splicing factors deserve further analysis and discussion. Here, we summarize the function of SRSF3-regulated alternative transcripts in cancer cell biology at different stages of tumor development and the regulation of SRSF3 in tumorigenesis.
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Affiliation(s)
- Yingying Che
- Institute of Chronic Disease, Qingdao Municipal Hospital, Qingdao University, Qingdao 266000, China
| | - Lin Fu
- Institute of Chronic Disease, Qingdao Municipal Hospital, Qingdao University, Qingdao 266000, China
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30
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Pathway-guided analysis identifies Myc-dependent alternative pre-mRNA splicing in aggressive prostate cancers. Proc Natl Acad Sci U S A 2020; 117:5269-5279. [PMID: 32086391 PMCID: PMC7071906 DOI: 10.1073/pnas.1915975117] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We sought to define the landscape of alternative pre-mRNA splicing in prostate cancers and the relationship of exon choice to known cancer driver alterations. To do so, we compiled a metadataset composed of 876 RNA-sequencing (RNA-Seq) samples from five publicly available sources representing a range of prostate phenotypes from normal tissue to drug-resistant metastases. We subjected these samples to exon-level analysis with rMATS-turbo, purpose-built software designed for large-scale analyses of splicing, and identified 13,149 high-confidence cassette exon events with variable incorporation across samples. We then developed a computational framework, pathway enrichment-guided activity study of alternative splicing (PEGASAS), to correlate transcriptional signatures of 50 different cancer driver pathways with these alternative splicing events. We discovered that Myc signaling was correlated with incorporation of a set of 1,039 cassette exons enriched in genes encoding RNA binding proteins. Using a human prostate epithelial transformation assay, we confirmed the Myc regulation of 147 of these exons, many of which introduced frameshifts or encoded premature stop codons. Our results connect changes in alternative pre-mRNA splicing to oncogenic alterations common in prostate and many other cancers. We also establish a role for Myc in regulating RNA splicing by controlling the incorporation of nonsense-mediated decay-determinant exons in genes encoding RNA binding proteins.
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31
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Thomas JD, Polaski JT, Feng Q, De Neef EJ, Hoppe ER, McSharry MV, Pangallo J, Gabel AM, Belleville AE, Watson J, Nkinsi NT, Berger AH, Bradley RK. RNA isoform screens uncover the essentiality and tumor-suppressor activity of ultraconserved poison exons. Nat Genet 2020; 52:84-94. [PMID: 31911676 PMCID: PMC6962552 DOI: 10.1038/s41588-019-0555-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 11/21/2019] [Indexed: 12/30/2022]
Abstract
While RNA-seq has enabled comprehensive quantification of alternative splicing, no correspondingly high-throughput assay exists for functionally interrogating individual isoforms. We describe pgFARM (paired guide RNAs for alternative exon removal), a CRISPR-Cas9-based method to manipulate isoforms independent of gene inactivation. This approach enabled rapid suppression of exon recognition in polyclonal settings to identify functional roles for individual exons, such as an SMNDC1 cassette exon that regulates pan-cancer intron retention. We generalized this method to a pooled screen to measure the functional relevance of 'poison' cassette exons, which disrupt their host genes' reading frames yet are frequently ultraconserved. Many poison exons were essential for the growth of both cultured cells and lung adenocarcinoma xenografts, while a subset had clinically relevant tumor-suppressor activity. The essentiality and cancer relevance of poison exons are likely to contribute to their unusually high conservation and contrast with the dispensability of other ultraconserved elements for viability.
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Affiliation(s)
- James D Thomas
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Jacob T Polaski
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Qing Feng
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Emma J De Neef
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Emma R Hoppe
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Maria V McSharry
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Joseph Pangallo
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Austin M Gabel
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
- Medical Scientist Training Program, University of Washington, Seattle, WA, USA
| | - Andrea E Belleville
- Medical Scientist Training Program, University of Washington, Seattle, WA, USA
| | - Jacqueline Watson
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Naomi T Nkinsi
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Alice H Berger
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Robert K Bradley
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
- Department of Genome Sciences, University of Washington, Seattle, WA, USA.
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32
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Hochberg-Laufer H, Neufeld N, Brody Y, Nadav-Eliyahu S, Ben-Yishay R, Shav-Tal Y. Availability of splicing factors in the nucleoplasm can regulate the release of mRNA from the gene after transcription. PLoS Genet 2019; 15:e1008459. [PMID: 31765392 PMCID: PMC6901260 DOI: 10.1371/journal.pgen.1008459] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 12/09/2019] [Accepted: 10/04/2019] [Indexed: 11/18/2022] Open
Abstract
Gene expression dynamics can be measured in single living cells. Using a detectable transcriptionally active gene in living cells, we previously found that an mRNA undergoing several splicing events was retained at this gene after transcription until completion of mRNA processing. To determine the reason for this delay in release and whether mRNA retention on the gene might depend on splicing factor availability, we modulated the levels of splicing factors in the nucleus. Increasing the abundance of the diffusing fraction of splicing factors by their overexpression or by Clk1 kinase overexpression to disassemble nuclear speckles, led to a reduction in splicing factor residence times on the active gene, and the retained mRNA was rapidly released from the gene. Other treatments such as overexpression of a mutant inactive Clk1, the downregulation of MALAT1 lncRNA or of the Son protein, or the overexpression of the splicing factor import factor TNPO3, did not affect the dynamics of mRNA release from the gene. We found that the faster release of the mRNA from the gene mediated by increased availability of splicing factors, was dependent on the RS domain of the splicing factors and its phosphorylation state. We propose that the relative abundancies of splicing factors in the nucleoplasm can affect their availability for the splicing events taking place, and regulate the kinetics of mRNA release from the gene after processing. Genetic information is contained in the cell nucleus and encodes proteins. However, protein production takes place in the cytoplasm, and so a molecule is needed to connect between the nucleus and cytoplasm. This messenger molecule is called messenger RNA (mRNA). It is produced and copied from the DNA, and after some processing will travel to the cytoplasm to encode proteins. This study focuses on the timing of mRNA release from the gene after it is copied from the DNA. Processing of mRNA includes the removal of some of its pieces and the stitching back of the remaining parts. This is called splicing. We found that mRNAs undergoing many splicing events are retained on the gene until splicing has completed, and examined what is the cause for this delay. We found that the factors performing the splicing might be limiting the process if their levels are not high enough at the gene locus. By increasing splicing factor levels in the nucleus we show that their abundance increases the rate at which mRNA is released. This means that the cell can regulate gene expression rates by limiting the availability of splicing factors that are free to take part in the processing of mRNA.
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Affiliation(s)
- Hodaya Hochberg-Laufer
- The Mina & Everard Goodman Faculty of Life Sciences & Institute of Nanotechnology, Bar-Ilan University, Ramat Gan, Israel
| | - Noa Neufeld
- The Mina & Everard Goodman Faculty of Life Sciences & Institute of Nanotechnology, Bar-Ilan University, Ramat Gan, Israel
| | - Yehuda Brody
- The Mina & Everard Goodman Faculty of Life Sciences & Institute of Nanotechnology, Bar-Ilan University, Ramat Gan, Israel
| | - Shani Nadav-Eliyahu
- The Mina & Everard Goodman Faculty of Life Sciences & Institute of Nanotechnology, Bar-Ilan University, Ramat Gan, Israel
| | - Rakefet Ben-Yishay
- The Mina & Everard Goodman Faculty of Life Sciences & Institute of Nanotechnology, Bar-Ilan University, Ramat Gan, Israel
| | - Yaron Shav-Tal
- The Mina & Everard Goodman Faculty of Life Sciences & Institute of Nanotechnology, Bar-Ilan University, Ramat Gan, Israel
- * E-mail:
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33
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Xu L, Shen J, Jia J, Jia R. Inclusion of hnRNP L Alternative Exon 7 Is Associated with Good Prognosis and Inhibited by Oncogene SRSF3 in Head and Neck Squamous Cell Carcinoma. BIOMED RESEARCH INTERNATIONAL 2019; 2019:9612425. [PMID: 31828152 PMCID: PMC6885243 DOI: 10.1155/2019/9612425] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/22/2019] [Accepted: 10/11/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND OBJECTIVES Alternative splicing is increasingly associated with cancers. HnRNP L is a splicing factor that promotes carcinogenesis in head and neck squamous cell carcinoma (HNSCC) and other cancers. Alternative exon 7 of hnRNP L contains an in-frame stop codon. Exon 7-included transcripts can be degraded via nonsense-mediated decay or encode a truncated hnRNP L protein. Exon 7-excluded transcripts can encode full-length functional hnRNP L protein. HnRNP L has an autoregulation mechanism by promoting the inclusion of its own exon 7. This study aimed to understand the relationship between the alternative splicing of exon 7 and HNSCC. Oncogenic splicing factor SRSF3 has an alternative exon 4 and similar autoregulation mechanism. HnRNP L promotes SRSF3 exon 4 inclusion and then inhibits SRSF3 autoregulation. MATERIALS AND METHODS The relationship between alternative splicing of hnRNP L exon 7 and clinical characteristics of HNSCC in a TCGA dataset was analyzed and confirmed by RT-PCR in a cohort of 61 oral squamous cell carcinoma (OSCC) patients. The regulators of exon 7 splicing were screened in 29 splicing factors and confirmed by overexpression or silencing assay in HEK 293, CAL 27, and SCC-9 cell lines. RESULTS The inclusion of hnRNP L exon 7 was significantly negatively associated with the progression and prognosis of HNSCC, which was confirmed in the cohort of 61 OSCC patients. SRSF3 inhibited exon 7 inclusion and hnRNP L autoregulation and then promoted the expression of full-length functional hnRNP L protein. SRSF3 exon 4 inclusion was correlated with hnRNP L exon 7 inclusion in both HNSCC and breast cancer. HNSCC patients with both low hnRNP L exon 7 and SRSF3 exon 4 inclusion show poor overall survival. CONCLUSIONS Inclusion of hnRNP L alternative exon 7 is associated with good prognosis and inhibited by oncogene SRSF3 in HNSCC.
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Affiliation(s)
- Lingfeng Xu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Jiaoxiang Shen
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
- Department of Orthodontics, Xiamen Stomatology Hospital, Hospital and School of Stomatology, Xiamen Medical University, Xiamen, China
| | - Jun Jia
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
- Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, Wuhan 430079, China
| | - Rong Jia
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
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34
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Jiménez M, Urtasun R, Elizalde M, Azkona M, Latasa MU, Uriarte I, Arechederra M, Alignani D, Bárcena-Varela M, Álvarez-Sola G, Colyn L, Santamaría E, Sangro B, Rodriguez-Ortigosa C, Fernández-Barrena MG, Ávila MA, Berasain C. Splicing events in the control of genome integrity: role of SLU7 and truncated SRSF3 proteins. Nucleic Acids Res 2019; 47:3450-3466. [PMID: 30657957 PMCID: PMC6468163 DOI: 10.1093/nar/gkz014] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 11/21/2018] [Accepted: 01/08/2019] [Indexed: 12/13/2022] Open
Abstract
Genome instability is related to disease development and carcinogenesis. DNA lesions are caused by genotoxic compounds but also by the dysregulation of fundamental processes like transcription, DNA replication and mitosis. Recent evidence indicates that impaired expression of RNA-binding proteins results in mitotic aberrations and the formation of transcription-associated RNA-DNA hybrids (R-loops), events strongly associated with DNA injury. We identify the splicing regulator SLU7 as a key mediator of genome stability. SLU7 knockdown results in R-loops formation, DNA damage, cell-cycle arrest and severe mitotic derangements with loss of sister chromatid cohesion (SCC). We define a molecular pathway through which SLU7 keeps in check the generation of truncated forms of the splicing factor SRSF3 (SRp20) (SRSF3-TR). Behaving as dominant negative, or by gain-of-function, SRSF3-TR impair the correct splicing and expression of the splicing regulator SRSF1 (ASF/SF2) and the crucial SCC protein sororin. This unique function of SLU7 was found in cancer cells of different tissue origin and also in the normal mouse liver, demonstrating a conserved and fundamental role of SLU7 in the preservation of genome integrity. Therefore, the dowregulation of SLU7 and the alterations of this pathway that we observe in the cirrhotic liver could be involved in the process of hepatocarcinogenesis.
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Affiliation(s)
- Maddalen Jiménez
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain
| | - Raquel Urtasun
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain.,Instituto de Investigaciones Sanitarias de Navarra-IdiSNA, Pamplona 31008, Spain
| | - María Elizalde
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain
| | - María Azkona
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain
| | - M Ujue Latasa
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain
| | - Iker Uriarte
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain.,CIBERehd, Instituto de Salud Carlos III, Madrid 28029, Spain
| | - María Arechederra
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain
| | - Diego Alignani
- Instituto de Investigaciones Sanitarias de Navarra-IdiSNA, Pamplona 31008, Spain.,Cytometry Unit, CIMA, University of Navarra, Pamplona 31008, Spain
| | | | - Gloria Álvarez-Sola
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain.,CIBERehd, Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Leticia Colyn
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain
| | - Eva Santamaría
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain.,CIBERehd, Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Bruno Sangro
- Instituto de Investigaciones Sanitarias de Navarra-IdiSNA, Pamplona 31008, Spain.,CIBERehd, Instituto de Salud Carlos III, Madrid 28029, Spain.,Hepatology Unit, Navarra University Clinic, Pamplona 31008, Spain
| | - Carlos Rodriguez-Ortigosa
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain.,Instituto de Investigaciones Sanitarias de Navarra-IdiSNA, Pamplona 31008, Spain.,CIBERehd, Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Maite G Fernández-Barrena
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain.,Instituto de Investigaciones Sanitarias de Navarra-IdiSNA, Pamplona 31008, Spain.,CIBERehd, Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Matías A Ávila
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain.,Instituto de Investigaciones Sanitarias de Navarra-IdiSNA, Pamplona 31008, Spain.,CIBERehd, Instituto de Salud Carlos III, Madrid 28029, Spain
| | - Carmen Berasain
- Hepatology Program, CIMA, University of Navarra, Pamplona 31008, Spain.,Instituto de Investigaciones Sanitarias de Navarra-IdiSNA, Pamplona 31008, Spain.,CIBERehd, Instituto de Salud Carlos III, Madrid 28029, Spain
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35
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Kumar D, Das M, Sauceda C, Ellies LG, Kuo K, Parwal P, Kaur M, Jih L, Bandyopadhyay GK, Burton D, Loomba R, Osborn O, Webster NJ. Degradation of splicing factor SRSF3 contributes to progressive liver disease. J Clin Invest 2019; 129:4477-4491. [PMID: 31393851 DOI: 10.1172/jci127374] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Serine rich splicing factor 3 (SRSF3) plays a critical role in liver function and its loss promotes chronic liver damage and regeneration. As a consequence, genetic deletion of SRSF3 in hepatocytes caused progressive liver disease and ultimately led to hepatocellular carcinoma. Here we show that SRSF3 is decreased in human liver samples with non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), or cirrhosis that was associated with alterations in RNA splicing of known SRSF3 target genes. Hepatic SRSF3 expression was similarly decreased and RNA splicing dysregulated in mouse models of NAFLD and NASH. We showed that palmitic acid-induced oxidative stress caused conjugation of the ubiquitin like NEDD8 protein to SRSF3 and proteasome mediated degradation. SRSF3 was selectively neddylated at lysine11 and mutation of this residue (SRSF3-K11R) was sufficient to prevent both SRSF3 degradation and alterations in RNA splicing. Finally prevention of SRSF3 degradation in vivo partially protected mice from hepatic steatosis, fibrosis and inflammation. These results highlight a neddylation-dependent mechanism regulating gene expression in the liver that is disrupted in early metabolic liver disease and may contribute to the progression to NASH, cirrhosis and ultimately hepatocellular carcinoma.
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Affiliation(s)
- Deepak Kumar
- VA San Diego Healthcare System, San Diego, California, USA.,Department of Medicine
| | | | - Consuelo Sauceda
- VA San Diego Healthcare System, San Diego, California, USA.,Department of Medicine
| | - Lesley G Ellies
- Department of Pathology, and.,Moores Cancer Center, UCSD, La Jolla, California, USA
| | | | | | | | - Lily Jih
- VA San Diego Healthcare System, San Diego, California, USA
| | | | - Douglas Burton
- VA San Diego Healthcare System, San Diego, California, USA
| | - Rohit Loomba
- Department of Medicine.,Moores Cancer Center, UCSD, La Jolla, California, USA
| | | | - Nicholas Jg Webster
- VA San Diego Healthcare System, San Diego, California, USA.,Department of Medicine.,Moores Cancer Center, UCSD, La Jolla, California, USA
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36
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Genetic variations within alternative splicing associated genes are associated with breast cancer susceptibility in Chinese women. Gene 2019; 706:140-145. [DOI: 10.1016/j.gene.2019.05.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 05/06/2019] [Accepted: 05/08/2019] [Indexed: 11/20/2022]
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37
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Black KL, Naqvi AS, Asnani M, Hayer KE, Yang SY, Gillespie E, Bagashev A, Pillai V, Tasian SK, Gazzara MR, Carroll M, Taylor D, Lynch KW, Barash Y, Thomas-Tikhonenko A. Aberrant splicing in B-cell acute lymphoblastic leukemia. Nucleic Acids Res 2019; 46:11357-11369. [PMID: 30357359 PMCID: PMC6277088 DOI: 10.1093/nar/gky946] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 10/04/2018] [Indexed: 12/14/2022] Open
Abstract
Aberrant splicing is a hallmark of leukemias with mutations in splicing factor (SF)-encoding genes. Here we investigated its prevalence in pediatric B-cell acute lymphoblastic leukemias (B-ALL), where SFs are not mutated. By comparing these samples to normal pro-B cells, we found thousands of aberrant local splice variations (LSVs) per sample, with 279 LSVs in 241 genes present in every comparison. These genes were enriched in RNA processing pathways and encoded ∼100 SFs, e.g. hnRNPA1. HNRNPA1 3'UTR was most pervasively mis-spliced, yielding the transcript subject to nonsense-mediated decay. To mimic this event, we knocked it down in B-lymphoblastoid cells and identified 213 hnRNPA1-regulated exon usage events comprising the hnRNPA1 splicing signature in pediatric leukemia. Some of its elements were LSVs in DICER1 and NT5C2, known cancer drivers. We searched for LSVs in other leukemia and lymphoma drivers and discovered 81 LSVs in 41 additional genes. Seventy-seven LSVs out of 81 were confirmed using two large independent B-ALL RNA-seq datasets, and the twenty most common B-ALL drivers, including NT5C2, showed higher prevalence of aberrant splicing than of somatic mutations. Thus, post-transcriptional deregulation of SF can drive widespread changes in B-ALL splicing and likely contributes to disease pathogenesis.
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Affiliation(s)
- Kathryn L Black
- Department of Pathology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Ammar S Naqvi
- Department of Pathology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.,Department of Biomedical & Health Informatics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Mukta Asnani
- Department of Pathology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Katharina E Hayer
- Department of Pathology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.,Department of Biomedical & Health Informatics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Scarlett Y Yang
- Department of Pathology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.,Immunology Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Elisabeth Gillespie
- Department of Pathology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Asen Bagashev
- Department of Pathology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Vinodh Pillai
- Department of Pathology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Sarah K Tasian
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Matthew R Gazzara
- Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Martin Carroll
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Deanne Taylor
- Department of Biomedical & Health Informatics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.,Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kristen W Lynch
- Immunology Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Biochemistry & Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yoseph Barash
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Computer and Information Science, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Andrei Thomas-Tikhonenko
- Department of Pathology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.,Immunology Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Pathology & Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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38
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Ortiz-Sánchez P, Villalba-Orero M, López-Olañeta MM, Larrasa-Alonso J, Sánchez-Cabo F, Martí-Gómez C, Camafeita E, Gómez-Salinero JM, Ramos-Hernández L, Nielsen PJ, Vázquez J, Müller-McNicoll M, García-Pavía P, Lara-Pezzi E. Loss of SRSF3 in Cardiomyocytes Leads to Decapping of Contraction-Related mRNAs and Severe Systolic Dysfunction. Circ Res 2019; 125:170-183. [PMID: 31145021 PMCID: PMC6615931 DOI: 10.1161/circresaha.118.314515] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE RBPs (RNA binding proteins) play critical roles in the cell by regulating mRNA transport, splicing, editing, and stability. The RBP SRSF3 (serine/arginine-rich splicing factor 3) is essential for blastocyst formation and for proper liver development and function. However, its role in the heart has not been explored. OBJECTIVE To investigate the role of SRSF3 in cardiac function. METHODS AND RESULTS Cardiac SRSF3 expression was high at mid gestation and decreased during late embryonic development. Mice lacking SRSF3 in the embryonic heart showed impaired cardiomyocyte proliferation and died in utero. In the adult heart, SRSF3 expression was reduced after myocardial infarction, suggesting a possible role in cardiac homeostasis. To determine the role of this RBP in the adult heart, we used an inducible, cardiomyocyte-specific SRSF3 knockout mouse model. After SRSF3 depletion in cardiomyocytes, mice developed severe systolic dysfunction that resulted in death within 8 days. RNA-Seq analysis revealed downregulation of mRNAs encoding sarcomeric and calcium handling proteins. Cardiomyocyte-specific SRSF3 knockout mice also showed evidence of alternative splicing of mTOR (mammalian target of rapamycin) mRNA, generating a shorter protein isoform lacking catalytic activity. This was associated with decreased phosphorylation of 4E-BP1 (eIF4E-binding protein 1), a protein that binds to eIF4E (eukaryotic translation initiation factor 4E) and prevents mRNA decapping. Consequently, we found increased decapping of mRNAs encoding proteins involved in cardiac contraction. Decapping was partially reversed by mTOR activation. CONCLUSIONS We show that cardiomyocyte-specific loss of SRSF3 expression results in decapping of critical mRNAs involved in cardiac contraction. The molecular mechanism underlying this effect likely involves the generation of a short mTOR isoform by alternative splicing, resulting in reduced 4E-BP1 phosphorylation. The identification of mRNA decapping as a mechanism of systolic heart failure may open the way to the development of urgently needed therapeutic tools.
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Affiliation(s)
- Paula Ortiz-Sánchez
- From the Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain (P.O.-S., M.V.-O., M.M.L.-O., J.L.-A., F.S.-C., C.M.-G., E.C., J.M.G.-S., L.R.-H., J.V., E.L.-P.).,Heart Failure and Inherited Cardiac Diseases Unit, Department of Cardiology, Hospital Universitario Puerta de Hierro, Madrid, Spain (P.O.-S., P.G.-P.)
| | - María Villalba-Orero
- From the Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain (P.O.-S., M.V.-O., M.M.L.-O., J.L.-A., F.S.-C., C.M.-G., E.C., J.M.G.-S., L.R.-H., J.V., E.L.-P.)
| | - Marina M López-Olañeta
- From the Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain (P.O.-S., M.V.-O., M.M.L.-O., J.L.-A., F.S.-C., C.M.-G., E.C., J.M.G.-S., L.R.-H., J.V., E.L.-P.)
| | - Javier Larrasa-Alonso
- From the Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain (P.O.-S., M.V.-O., M.M.L.-O., J.L.-A., F.S.-C., C.M.-G., E.C., J.M.G.-S., L.R.-H., J.V., E.L.-P.)
| | - Fátima Sánchez-Cabo
- From the Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain (P.O.-S., M.V.-O., M.M.L.-O., J.L.-A., F.S.-C., C.M.-G., E.C., J.M.G.-S., L.R.-H., J.V., E.L.-P.)
| | - Carlos Martí-Gómez
- From the Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain (P.O.-S., M.V.-O., M.M.L.-O., J.L.-A., F.S.-C., C.M.-G., E.C., J.M.G.-S., L.R.-H., J.V., E.L.-P.)
| | - Emilio Camafeita
- From the Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain (P.O.-S., M.V.-O., M.M.L.-O., J.L.-A., F.S.-C., C.M.-G., E.C., J.M.G.-S., L.R.-H., J.V., E.L.-P.)
| | - Jesús M Gómez-Salinero
- From the Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain (P.O.-S., M.V.-O., M.M.L.-O., J.L.-A., F.S.-C., C.M.-G., E.C., J.M.G.-S., L.R.-H., J.V., E.L.-P.)
| | - Laura Ramos-Hernández
- From the Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain (P.O.-S., M.V.-O., M.M.L.-O., J.L.-A., F.S.-C., C.M.-G., E.C., J.M.G.-S., L.R.-H., J.V., E.L.-P.)
| | - Peter J Nielsen
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany (P.J.N.)
| | - Jesús Vázquez
- From the Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain (P.O.-S., M.V.-O., M.M.L.-O., J.L.-A., F.S.-C., C.M.-G., E.C., J.M.G.-S., L.R.-H., J.V., E.L.-P.).,Centro de Investigacion Biomedica en Red Cardiovascular (CIBERCV), Madrid, Spain (J.V., P.G.-P., E.L.-P)
| | - Michaela Müller-McNicoll
- Goethe-University Frankfurt, Institute of Cell Biology and Neuroscience, Frankfurt/Main, Germany (M.M.-M.)
| | - Pablo García-Pavía
- Heart Failure and Inherited Cardiac Diseases Unit, Department of Cardiology, Hospital Universitario Puerta de Hierro, Madrid, Spain (P.O.-S., P.G.-P.).,Centro de Investigacion Biomedica en Red Cardiovascular (CIBERCV), Madrid, Spain (J.V., P.G.-P., E.L.-P).,Facultad de Ciencias de la Salud, Universidad Francisco de Vitoria (UFV), Pozuelo de Alarcón, Madrid, Spain (P.G.-P.)
| | - Enrique Lara-Pezzi
- From the Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain (P.O.-S., M.V.-O., M.M.L.-O., J.L.-A., F.S.-C., C.M.-G., E.C., J.M.G.-S., L.R.-H., J.V., E.L.-P.).,Centro de Investigacion Biomedica en Red Cardiovascular (CIBERCV), Madrid, Spain (J.V., P.G.-P., E.L.-P).,National Heart and Lung Institute, Imperial College London, United Kingdom (E.L.-P.)
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39
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Wang H, Lekbaby B, Fares N, Augustin J, Attout T, Schnuriger A, Cassard AM, Panasyuk G, Perlemuter G, Bieche I, Vacher S, Selves J, Péron JM, Bancel B, Merle P, Kremsdorf D, Hall J, Chemin I, Soussan P. Alteration of splicing factors' expression during liver disease progression: impact on hepatocellular carcinoma outcome. Hepatol Int 2019; 13:454-467. [PMID: 31140152 DOI: 10.1007/s12072-019-09950-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 04/29/2019] [Indexed: 12/29/2022]
Abstract
PURPOSE Trans-acting splicing factors (SF) shape the eukaryotic transcriptome by regulating alternative splicing (AS). This process is recurrently modulated in liver cancer suggesting its direct contribution to the course of liver disease. The aim of our study was to investigate the relationship between the regulation of SFs expression and liver damage. METHODS The expression profile of 10 liver-specific SF and the AS events of 7 genes associated with liver disorders was assessed by western-blotting in 6 murine models representing different stages of liver damage, from inflammation to hepatocellular carcinoma (HCC). Relevant SFs (PSF, SRSF3, and SRSF6) and target genes (INSR, SRSF3, and SLK) modulated in mice were investigated in a cohort of 179 HCC patients. RESULTS Each murine model of liver disease was characterized by a unique SF expression profile. Changes in the SF profile did not affect AS events of the selected genes despite the presence of corresponding splicing sites. In human HCC expression of SFs, including the tumor-suppressor SRSF3, and AS regulation of genes studied were frequently upregulated in tumor versus non-tumor tissues. Risk of tumor recurrence positively correlated with AS isoform of the INSR gene. In contrast, increased levels of SFs expression correlated with an extended overall survival of patients. CONCLUSIONS Dysregulation of SF expression is an early event occurring during liver injury and not just at the stage of HCC. Besides impacting on AS regulation, overexpression of SF may contribute to preserving hepatocyte homeostasis during liver pathogenesis.
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Affiliation(s)
- Hualin Wang
- INSERM U1135, Centre d'immunologie et de maladie infectieuse, 91 boulevard de l'Hôpital, 75013, Paris, France.,Sorbonne Université, Paris, France
| | - Bouchra Lekbaby
- INSERM U1135, Centre d'immunologie et de maladie infectieuse, 91 boulevard de l'Hôpital, 75013, Paris, France.,Sorbonne Université, Paris, France
| | - Nadim Fares
- Centre de Recherche en Cancérologie de Lyon, UMR INSERM 1052, CNRS 5286, Lyon Cedex 03, France
| | - Jeremy Augustin
- INSERM U1135, Centre d'immunologie et de maladie infectieuse, 91 boulevard de l'Hôpital, 75013, Paris, France.,Sorbonne Université, Paris, France
| | - Tarik Attout
- INSERM U1135, Centre d'immunologie et de maladie infectieuse, 91 boulevard de l'Hôpital, 75013, Paris, France.,Sorbonne Université, Paris, France
| | - Aurelie Schnuriger
- INSERM U1135, Centre d'immunologie et de maladie infectieuse, 91 boulevard de l'Hôpital, 75013, Paris, France.,Sorbonne Université, Paris, France.,Département de Virologie, Hôpitaux Est Parisien, Paris, France
| | - Anne-Marie Cassard
- Faculté de médecine Paris-Sud, Université Paris-Sud, 94270, Kremlin-Bicêtre, France
| | - Ganna Panasyuk
- Institut Necker-Enfants Malades, Université Paris Descartes, Paris, France.,INSERM U1151/CNRS Unité Mixte de Recherche (UMR) 8253, Paris, France
| | - Gabriel Perlemuter
- Faculté de médecine Paris-Sud, Université Paris-Sud, 94270, Kremlin-Bicêtre, France.,AP-HP, Hôpital Antoine Béclère, Service d'hépato-gastroentérologie, 92140, Clamart, France
| | | | | | - Janick Selves
- Institut Universitaire de Cancérologie de Toulouse Oncopole, Université Paul Sabatier, Toulouse, France
| | - Jean-Marie Péron
- Institut Universitaire de Cancérologie de Toulouse Oncopole, Université Paul Sabatier, Toulouse, France
| | - Brigitte Bancel
- Centre de Recherche en Cancérologie de Lyon, UMR INSERM 1052, CNRS 5286, Lyon Cedex 03, France
| | - Philippe Merle
- Centre de Recherche en Cancérologie de Lyon, UMR INSERM 1052, CNRS 5286, Lyon Cedex 03, France
| | - Dina Kremsdorf
- INSERM U1135, Centre d'immunologie et de maladie infectieuse, 91 boulevard de l'Hôpital, 75013, Paris, France.,Sorbonne Université, Paris, France
| | - Janet Hall
- Centre de Recherche en Cancérologie de Lyon, UMR INSERM 1052, CNRS 5286, Lyon Cedex 03, France
| | - Isabelle Chemin
- Centre de Recherche en Cancérologie de Lyon, UMR INSERM 1052, CNRS 5286, Lyon Cedex 03, France
| | - Patrick Soussan
- INSERM U1135, Centre d'immunologie et de maladie infectieuse, 91 boulevard de l'Hôpital, 75013, Paris, France. .,Sorbonne Université, Paris, France. .,Département de Virologie, Hôpitaux Est Parisien, Paris, France.
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Tam AS, Stirling PC. Splicing, genome stability and disease: splice like your genome depends on it! Curr Genet 2019; 65:905-912. [PMID: 30953124 DOI: 10.1007/s00294-019-00964-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 03/27/2019] [Accepted: 03/28/2019] [Indexed: 12/21/2022]
Abstract
The spliceosome has been implicated in genome maintenance for decades. Recently, a surge in discoveries in cancer has suggested that the oncogenic mechanism of spliceosomal defects may involve defective genome stability. The action of the core spliceosome prevents R-loop accumulation, and regulates the expression of genome stability factors. At the same time, specific spliceosomal components have non-canonical functions in genome maintenance. Here we review these different models, highlighting their discovery in different model systems, and describing their potential impact on human disease states.
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Affiliation(s)
- Annie S Tam
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Peter C Stirling
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, Canada.
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.
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Dembic M, Andersen HS, Bastin J, Doktor TK, Corydon TJ, Sass JO, Lopes Costa A, Djouadi F, Andresen BS. Next generation sequencing of RNA reveals novel targets of resveratrol with possible implications for Canavan disease. Mol Genet Metab 2019; 126:64-76. [PMID: 30446350 DOI: 10.1016/j.ymgme.2018.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 10/17/2018] [Accepted: 10/19/2018] [Indexed: 12/21/2022]
Abstract
Resveratrol (RSV) is a small compound first identified as an activator of sirtuin 1 (SIRT1), a key factor in mediating the effects of caloric restriction. Since then, RSV received great attention for its widespread beneficial effects on health and in connection to many diseases. RSV improves the metabolism and the mitochondrial function, and more recently it was shown to restore fatty acid β-oxidation (FAO) capacities in patient fibroblasts harboring mutations with residual enzyme activity. Many of RSV's beneficial effects are mediated by the transcriptional coactivator PGC-1α, a direct target of SIRT1 and a master regulator of the mitochondrial fatty acid oxidation. Despite numerous studies RSV's mechanism of action is still not completely elucidated. Our aim was to investigate the effects of RSV on gene regulation on a wide scale, possibly to detect novel genes whose up-regulation by RSV may be of interest with respect to disease treatment. We performed Next Generation Sequencing of RNA on normal fibroblasts treated with RSV. To investigate whether the effects of RSV are mediated through SIRT1 we expanded the analysis to include SIRT1-knockdown fibroblasts. We identified the aspartoacylase (ASPA) gene, mutated in Canavan disease, to be strongly up-regulated by RSV in several cell lines, including Canavan disease fibroblasts. We further link RSV to the up-regulation of other genes involved in myelination including the glial specific transcription factors POU3F1, POU3F2, and myelin basic protein (MBP). We also observe a strong up-regulation by RSV of the riboflavin transporter gene SLC52a1. Mutations in SLC52a1 cause transient multiple acyl-CoA dehydrogenase deficiency (MADD). Our analysis of alternative splicing identified novel metabolically important genes affected by RSV, among which is particularly interesting the α subunit of the stimulatory G protein (Gsα), which regulates the cellular levels of cAMP through adenylyl cyclase. We conclude that in fibroblasts RSV stimulates the PGC-1α and p53 pathways, and up-regulates genes affecting the glucose metabolism, mitochondrial β-oxidation, and mitochondrial biogenesis. We further confirm that RSV might be a relevant treatment in the correction of FAO deficiencies and we suggest that treatment in other metabolic disorders including Canavan disease and MADD might be also beneficial.
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Affiliation(s)
- Maja Dembic
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
| | - Henriette S Andersen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
| | - Jean Bastin
- INSERM UMR-S 1124, Université Paris Descartes, UFR Biomédicale des Saints-Pères, 45, rue des Saints-Pères, 75270 Paris, cedex 06, France
| | - Thomas K Doktor
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
| | - Thomas J Corydon
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark; Department of Ophthalmology, Aarhus University Hospital, 8000 Aarhus C, Denmark.
| | - Jörn Oliver Sass
- Research Group Inborn Errors of Metabolism, Department of Natural Sciences & IFGA, University of Applied Sciences, Rheinbach, Germany.
| | - Alexandra Lopes Costa
- INSERM UMR-S 1124, Université Paris Descartes, UFR Biomédicale des Saints-Pères, 45, rue des Saints-Pères, 75270 Paris, cedex 06, France
| | - Fatima Djouadi
- INSERM UMR-S 1124, Université Paris Descartes, UFR Biomédicale des Saints-Pères, 45, rue des Saints-Pères, 75270 Paris, cedex 06, France
| | - Brage S Andresen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark.
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Nguyen HM, Nguyen TD, Nguyen TL, Nguyen TA. Orientation of Human Microprocessor on Primary MicroRNAs. Biochemistry 2018; 58:189-198. [DOI: 10.1021/acs.biochem.8b00944] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Huong Minh Nguyen
- Laboratory of Molecular Microbiology, Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Trung Duc Nguyen
- Division of Life Science, Hong Kong University of Science & Technology, Hong Kong, China
| | - Thuy Linh Nguyen
- Division of Life Science, Hong Kong University of Science & Technology, Hong Kong, China
| | - Tuan Anh Nguyen
- Division of Life Science, Hong Kong University of Science & Technology, Hong Kong, China
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Long Y, Sou WH, Yung KWY, Liu H, Wan SWC, Li Q, Zeng C, Law COK, Chan GHC, Lau TCK, Ngo JCK. Distinct mechanisms govern the phosphorylation of different SR protein splicing factors. J Biol Chem 2018; 294:1312-1327. [PMID: 30478176 DOI: 10.1074/jbc.ra118.003392] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 11/17/2018] [Indexed: 01/30/2023] Open
Abstract
Serine-arginine (SR) proteins are essential splicing factors containing a canonical RNA recognition motif (RRM), sometimes followed by a pseudo-RRM, and a C-terminal arginine/serine-rich (RS) domain that undergoes multisite phosphorylation. Phosphorylation regulates the localization and activity of SR proteins, and thus may provide insight into their differential biological roles. The phosphorylation mechanism of the prototypic SRSF1 by serine-arginine protein kinase 1 (SRPK1) has been well-studied, but little is known about the phosphorylation of other SR protein members. In the present study, interaction and kinetic assays unveiled how SRSF1 and the single RRM-containing SRSF3 are phosphorylated by SRPK2, another member of the SRPK family. We showed that a conserved SRPK-specific substrate-docking groove in SRPK2 impacts the binding and phosphorylation of both SR proteins, and the localization of SRSF3. We identified a nonconserved residue within the groove that affects the kinase processivity. We demonstrated that, in contrast to SRSF1, for which SRPK-mediated phosphorylation is confined to the N-terminal region of the RS domain, SRSF3 phosphorylation sites are spread throughout its entire RS domain in vitro Despite this, SRSF3 appears to be hypophosphorylated in cells at steady state. Our results suggest that the absence of a pseudo-RRM renders the single RRM-containing SRSF3 more susceptible to dephosphorylation by phosphatase. These findings suggest that the single RRM- and two RRM-containing SR proteins represent two subclasses of phosphoproteins in which phosphorylation statuses are maintained by unique mechanisms, and pose new directions to explore the distinct roles of SR proteins in vivo.
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Affiliation(s)
- Yunxin Long
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
| | - Weng Hong Sou
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
| | - Kristen Wing Yu Yung
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
| | - Haizhen Liu
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
| | - Stephanie Winn Chee Wan
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
| | - Qingyun Li
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
| | - Chuyue Zeng
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
| | - Carmen Oi Kwan Law
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Gordon Ho Ching Chan
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
| | - Terrence Chi Kong Lau
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Jacky Chi Ki Ngo
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
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Rawcliffe DFR, Österman L, Nordin A, Holmberg M. PTBP1 acts as a dominant repressor of the aberrant tissue-specific splicing of ISCU in hereditary myopathy with lactic acidosis. Mol Genet Genomic Med 2018; 6:887-897. [PMID: 30209894 PMCID: PMC6305642 DOI: 10.1002/mgg3.413] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 03/23/2018] [Accepted: 04/17/2018] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Hereditary myopathy with lactic acidosis (HML) is an autosomal recessive disease caused by an intron mutation in the iron-sulfur cluster assembly (ISCU) gene. The mutation results in aberrant splicing, where part of the intron is retained in the final mRNA transcript, giving rise to a truncated nonfunctional ISCU protein. Using an ISCU mini-gene system, we have previously shown that PTBP1 can act as a repressor of the mis-splicing of ISCU, where overexpression of PTBP1 resulted in a decrease of the incorrect splicing. In this study, we wanted to, in more detail, analyze the role of PTBP1 in the regulation of endogenous ISCU mis-splicing. METHODS Overexpression and knockdown of PTBP1 was performed in myoblasts from two HML patients and a healthy control. Quantification of ISCU mis-splicing was done by qRTPCR. Biotinylated ISCU RNA, representing wildtype and mutant intron sequence, was used in a pull-down assay with nuclear extracts from myoblasts. Levels of PTBP1 in human cell lines and mice tissues were analyzed by qRTPCR and western blot. RESULTS PTBP1 overexpression in HML patient myoblasts resulted in a substantial decrease of ISCU mis-splicing while knockdown of PTBP1 resulted in a drastic increase. The effect could be observed in both patient and control myoblasts. We could also show that PTBP1 interacts with both the mutant and wild-type ISCU intron sequence, but with a higher affinity to the mutant sequence. Furthermore, low levels of PTBP1 among examined mouse tissues correlated with high levels of incorrect splicing of ISCU. CONCLUSION Our results show that PTBP1 acts as a dominant repressor of ISCU mis-splicing. We also show an inverse correlation between the levels of PTBP1 and ISCU mis-splicing, suggesting that the high level of mis-splicing in the skeletal muscle is primarily due to the low levels of PTBP1.
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Affiliation(s)
- Denise F. R. Rawcliffe
- Unit for Medical and Clinical GeneticsDepartment of Medical BiosciencesUmeå UniversityUmeåSweden
| | - Lennart Österman
- Unit for Medical and Clinical GeneticsDepartment of Medical BiosciencesUmeå UniversityUmeåSweden
| | - Angelica Nordin
- Unit for Medical and Clinical GeneticsDepartment of Medical BiosciencesUmeå UniversityUmeåSweden
| | - Monica Holmberg
- Unit for Medical and Clinical GeneticsDepartment of Medical BiosciencesUmeå UniversityUmeåSweden
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Mitra M, Johnson EL, Swamy VS, Nersesian LE, Corney DC, Robinson DG, Taylor DG, Ambrus AM, Jelinek D, Wang W, Batista SL, Coller HA. Alternative polyadenylation factors link cell cycle to migration. Genome Biol 2018; 19:176. [PMID: 30360761 PMCID: PMC6203201 DOI: 10.1186/s13059-018-1551-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 09/25/2018] [Indexed: 12/12/2022] Open
Abstract
Background In response to a wound, fibroblasts are activated to migrate toward the wound, to proliferate and to contribute to the wound healing process. We hypothesize that changes in pre-mRNA processing occurring as fibroblasts enter the proliferative cell cycle are also important for promoting their migration. Results RNA sequencing of fibroblasts induced into quiescence by contact inhibition reveals downregulation of genes involved in mRNA processing, including splicing and cleavage and polyadenylation factors. These genes also show differential exon use, especially increased intron retention in quiescent fibroblasts compared to proliferating fibroblasts. Mapping the 3′ ends of transcripts reveals that longer transcripts from distal polyadenylation sites are more prevalent in quiescent fibroblasts and are associated with increased expression and transcript stabilization based on genome-wide transcript decay analysis. Analysis of dermal excisional wounds in mice reveals that proliferating cells adjacent to wounds express higher levels of cleavage and polyadenylation factors than quiescent fibroblasts in unwounded skin. Quiescent fibroblasts contain reduced levels of the cleavage and polyadenylation factor CstF-64. CstF-64 knockdown recapitulates changes in isoform selection and gene expression associated with quiescence, and results in slower migration. Conclusions Our findings support cleavage and polyadenylation factors as a link between cellular proliferation state and migration. Electronic supplementary material The online version of this article (10.1186/s13059-018-1551-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mithun Mitra
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, USA.,Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | | | - Vinay S Swamy
- Department of Biochemistry, University of California, Los Angeles, Los Angeles, CA, USA
| | - Lois E Nersesian
- Department of Chemical Engineering, University of California, Los Angeles, Los Angeles, CA, USA
| | - David C Corney
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, USA.,Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - David G Robinson
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Daniel G Taylor
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Aaron M Ambrus
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, USA
| | - David Jelinek
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Wei Wang
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Sandra L Batista
- Department of Computer Science, University of Southern California, Los Angeles, CA, USA
| | - Hilary A Coller
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, USA. .,Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
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Epstein-Barr Virus-Induced Nodules on Viral Replication Compartments Contain RNA Processing Proteins and a Viral Long Noncoding RNA. J Virol 2018; 92:JVI.01254-18. [PMID: 30068640 DOI: 10.1128/jvi.01254-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 07/23/2018] [Indexed: 11/20/2022] Open
Abstract
Profound alterations in host cell nuclear architecture accompany the lytic phase of Epstein-Barr virus (EBV) infection. Viral replication compartments assemble, host chromatin marginalizes to the nuclear periphery, cytoplasmic poly(A)-binding protein translocates to the nucleus, and polyadenylated mRNAs are sequestered within the nucleus. Virus-induced changes to nuclear architecture that contribute to viral host shutoff (VHS) must accommodate selective processing and export of viral mRNAs. Here we describe additional previously unrecognized nuclear alterations during EBV lytic infection in which viral and cellular factors that function in pre-mRNA processing and mRNA export are redistributed. Early during lytic infection, before formation of viral replication compartments, two cellular pre-mRNA splicing factors, SC35 and SON, were dispersed from interchromatin granule clusters, and three mRNA export factors, Y14, ALY, and NXF1, were depleted from the nucleus. During late lytic infection, virus-induced nodular structures (VINORCs) formed at the periphery of viral replication compartments. VINORCs were composed of viral (BMLF1 and BGLF5) and cellular (SC35, SON, SRp20, and NXF1) proteins that mediate pre-mRNA processing and mRNA export. BHLF1 long noncoding RNA was invariably found in VINORCs. VINORCs did not contain other nodular nuclear cellular proteins (PML or coilin), nor did they contain viral proteins (BRLF1 or BMRF1) found exclusively within replication compartments. VINORCs are novel EBV-induced nuclear structures. We propose that EBV-induced dispersal and depletion of pre-mRNA processing and mRNA export factors during early lytic infection contribute to VHS; subsequent relocalization of these pre-mRNA processing and mRNA export proteins to VINORCs and viral replication compartments facilitates selective processing and export of viral mRNAs.IMPORTANCE In order to make protein, mRNA transcribed from DNA in the nucleus must enter the cytoplasm. Nuclear export of mRNA requires correct processing of mRNAs by enzymes that function in splicing and nuclear export. During the Epstein-Barr virus (EBV) lytic cycle, nuclear export of cellular mRNAs is blocked, yet export of viral mRNAs is facilitated. Here we report the dispersal and dramatic reorganization of cellular (SC35, SON, SRp20, Y14, ALY, and NXF1) and viral (BMLF1 and BGLF5) proteins that play key roles in pre-mRNA processing and export of mRNA. These virus-induced nuclear changes culminate in formation of VINORCs, novel nodular structures composed of viral and cellular RNA splicing and export factors. VINORCs localize to the periphery of viral replication compartments, where viral mRNAs reside. These EBV-induced changes in nuclear organization may contribute to blockade of nuclear export of host mRNA, while enabling selective processing and export of viral mRNA.
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Yang S, Jia R, Bian Z. SRSF5 functions as a novel oncogenic splicing factor and is upregulated by oncogene SRSF3 in oral squamous cell carcinoma. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1161-1172. [DOI: 10.1016/j.bbamcr.2018.05.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/25/2018] [Accepted: 05/26/2018] [Indexed: 10/25/2022]
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Urbanski L, Leclair N, Anczuków O. Alternative-splicing defects in cancer: Splicing regulators and their downstream targets, guiding the way to novel cancer therapeutics. WILEY INTERDISCIPLINARY REVIEWS. RNA 2018; 9:e1476. [PMID: 29693319 PMCID: PMC6002934 DOI: 10.1002/wrna.1476] [Citation(s) in RCA: 221] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 12/14/2022]
Abstract
Defects in alternative splicing are frequently found in human tumors and result either from mutations in splicing-regulatory elements of specific cancer genes or from changes in the regulatory splicing machinery. RNA splicing regulators have emerged as a new class of oncoproteins and tumor suppressors, and contribute to disease progression by modulating RNA isoforms involved in the hallmark cancer pathways. Thus, dysregulation of alternative RNA splicing is fundamental to cancer and provides a potentially rich source of novel therapeutic targets. Here, we review the alterations in splicing regulatory factors detected in human tumors, as well as the resulting alternatively spliced isoforms that impact cancer hallmarks, and discuss how they contribute to disease pathogenesis. RNA splicing is a highly regulated process and, as such, the regulators are themselves tightly regulated. Differential transcriptional and posttranscriptional regulation of splicing factors modulates their levels and activities in tumor cells. Furthermore, the composition of the tumor microenvironment can also influence which isoforms are expressed in a given cell type and impact drug responses. Finally, we summarize current efforts in targeting alternative splicing, including global splicing inhibition using small molecules blocking the spliceosome or splicing-factor-modifying enzymes, as well as splice-switching RNA-based therapeutics to modulate cancer-specific splicing isoforms. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing.
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Kim K, Nguyen TD, Li S, Nguyen TA. SRSF3 recruits DROSHA to the basal junction of primary microRNAs. RNA (NEW YORK, N.Y.) 2018; 24:892-898. [PMID: 29615481 PMCID: PMC6004053 DOI: 10.1261/rna.065862.118] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Accepted: 03/29/2018] [Indexed: 05/22/2023]
Abstract
The Microprocessor complex, consisting of an RNase III DROSHA and the DGCR8 dimer, cleaves primary microRNA transcripts (pri-miRNAs) to initiate microRNA (miRNA) maturation. Pri-miRNAs are stem-loop RNAs, and ∼79% of them contain at least one of the three major and conserved RNA motifs, UG, UGU, and CNNC. We recently demonstrated that the basal UG and apical UGU motifs of pri-miRNAs interact with DROSHA and DGCR8, respectively. They help orient Microprocessor on pri-miRNA in a proper direction in which DROSHA and DGCR8 localize to the basal and apical pri-miRNA junctions, respectively. In addition, CNNC, located at ∼17 nucleotides (nt) from the Microprocessor cleavage site, interacts with SRSF3 (SRp20) to stimulate Microprocessor to process pri-miRNAs. The mechanism underlying this stimulation, however, is unknown. In this study, we discovered that SRSF3 recruits DROSHA to the basal junction in a CNNC-dependent manner, thereby enhancing Microprocessor activity. Furthermore, by generating various pri-miRNA substrates containing CNNC at different locations, we demonstrated that such stimulation only occurs when CNNC is located at ∼17 nt from the Microprocessor cleavage site. Our findings reveal the molecular mechanism of SRSF3 in pri-miRNA processing and support the previously proposed explanation for the highly conserved position of CNNC in SRSF3-enhanced pri-miRNA processing.
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Affiliation(s)
- Kijun Kim
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Trung Duc Nguyen
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China
- HKUST Shenzhen Research Institute, Shenzhen 518057, China
| | - Shaohua Li
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China
| | - Tuan Anh Nguyen
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China
- HKUST Shenzhen Research Institute, Shenzhen 518057, China
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50
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Do DV, Strauss B, Cukuroglu E, Macaulay I, Wee KB, Hu TX, Igor RDLM, Lee C, Harrison A, Butler R, Dietmann S, Jernej U, Marioni J, Smith CWJ, Göke J, Surani MA. SRSF3 maintains transcriptome integrity in oocytes by regulation of alternative splicing and transposable elements. Cell Discov 2018; 4:33. [PMID: 29928511 PMCID: PMC6006335 DOI: 10.1038/s41421-018-0032-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 01/19/2018] [Accepted: 03/28/2018] [Indexed: 02/08/2023] Open
Abstract
The RNA-binding protein SRSF3 (also known as SRp20) has critical roles in the regulation of pre-mRNA splicing. Zygotic knockout of Srsf3 results in embryo arrest at the blastocyst stage. However, SRSF3 is also present in oocytes, suggesting that it might be critical as a maternally inherited factor. Here we identify SRSF3 as an essential regulator of alternative splicing and of transposable elements to maintain transcriptome integrity in mouse oocyte. Using 3D time-lapse confocal live imaging, we show that conditional deletion of Srsf3 in fully grown germinal vesicle oocytes substantially compromises the capacity of germinal vesicle breakdown (GVBD), and consequently entry into meiosis. By combining single cell RNA-seq, and oocyte micromanipulation with steric blocking antisense oligonucleotides and RNAse-H inducing gapmers, we found that the GVBD defect in mutant oocytes is due to both aberrant alternative splicing and derepression of B2 SINE transposable elements. Together, our study highlights how control of transcriptional identity of the maternal transcriptome by the RNA-binding protein SRSF3 is essential to the development of fertilized-competent oocytes.
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Affiliation(s)
- Dang Vinh Do
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN UK
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY UK
| | - Bernhard Strauss
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN UK
| | - Engin Cukuroglu
- Computational and Systems Biology, Genome Institute of Singapore, 60 Biopolis Street, Singapore, 138672 Singapore
| | - Iain Macaulay
- Earlham Institute, Norwich Research Park, Norwich, NR4 7UH UK
| | - Keng Boon Wee
- Department Fluid Dynamics, Institute of High Performance Computing, 1 Fusionopolis Way, Singapore, 138632 Singapore
- Biomolecular Function Discovery Division, Bioinformatics Institute, 30 Biopolis Street, Singapore, 138671 Singapore
| | - Tim Xiaoming Hu
- EMBL European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, CB10 1SD, Cambridge, UK
| | | | - Caroline Lee
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN UK
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY UK
| | - Andrew Harrison
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN UK
| | - Richard Butler
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN UK
| | - Sabine Dietmann
- Wellcome Trust Medical Research Council Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR UK
| | - Ule Jernej
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - John Marioni
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE UK
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA UK
| | - Christopher W. J. Smith
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW UK
| | - Jonathan Göke
- Computational and Systems Biology, Genome Institute of Singapore, 60 Biopolis Street, Singapore, 138672 Singapore
| | - M. Azim Surani
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN UK
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY UK
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