1
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Li D, Yu W, Lai M. Towards understandings of serine/arginine-rich splicing factors. Acta Pharm Sin B 2023; 13:3181-3207. [PMID: 37655328 PMCID: PMC10465970 DOI: 10.1016/j.apsb.2023.05.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 04/13/2023] [Accepted: 05/06/2023] [Indexed: 09/02/2023] Open
Abstract
Serine/arginine-rich splicing factors (SRSFs) refer to twelve RNA-binding proteins which regulate splice site recognition and spliceosome assembly during precursor messenger RNA splicing. SRSFs also participate in other RNA metabolic events, such as transcription, translation and nonsense-mediated decay, during their shuttling between nucleus and cytoplasm, making them indispensable for genome diversity and cellular activity. Of note, aberrant SRSF expression and/or mutations elicit fallacies in gene splicing, leading to the generation of pathogenic gene and protein isoforms, which highlights the therapeutic potential of targeting SRSF to treat diseases. In this review, we updated current understanding of SRSF structures and functions in RNA metabolism. Next, we analyzed SRSF-induced aberrant gene expression and their pathogenic outcomes in cancers and non-tumor diseases. The development of some well-characterized SRSF inhibitors was discussed in detail. We hope this review will contribute to future studies of SRSF functions and drug development targeting SRSFs.
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Affiliation(s)
- Dianyang Li
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Wenying Yu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Maode Lai
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, China
- Department of Pathology, Research Unit of Intelligence Classification of Tumor Pathology and Precision Therapy, Chinese Academy of Medical Science (2019RU042), Key Laboratory of Disease Proteomics of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou 310058, China
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2
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SR Splicing Factors Promote Cancer via Multiple Regulatory Mechanisms. Genes (Basel) 2022; 13:genes13091659. [PMID: 36140826 PMCID: PMC9498594 DOI: 10.3390/genes13091659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/09/2022] [Accepted: 09/14/2022] [Indexed: 11/17/2022] Open
Abstract
Substantial emerging evidence supports that dysregulated RNA metabolism is associated with tumor initiation and development. Serine/Arginine-Rich proteins (SR) are a number of ultraconserved and structurally related proteins that contain a characteristic RS domain rich in arginine and serine residues. SR proteins perform a critical role in spliceosome assembling and conformational transformation, contributing to precise alternative RNA splicing. Moreover, SR proteins have been reported to participate in multiple other RNA-processing-related mechanisms than RNA splicing, such as genome stability, RNA export, and translation. The dysregulation of SR proteins has been reported to contribute to tumorigenesis through multiple mechanisms. Here we reviewed the different biological roles of SR proteins and strategies for functional rectification of SR proteins that may serve as potential therapeutic approaches for cancer.
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3
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Murphy AJ, Li AH, Li P, Sun H. Therapeutic Targeting of Alternative Splicing: A New Frontier in Cancer Treatment. Front Oncol 2022; 12:868664. [PMID: 35463320 PMCID: PMC9027816 DOI: 10.3389/fonc.2022.868664] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 03/11/2022] [Indexed: 01/05/2023] Open
Abstract
The ability for cells to harness alternative splicing enables them to diversify their proteome in order to carry out complex biological functions and adapt to external and internal stimuli. The spliceosome is the multiprotein-RNA complex charged with the intricate task of alternative splicing. Aberrant splicing can arise from abnormal spliceosomes or splicing factors and drive cancer development and progression. This review will provide an overview of the alternative splicing process and aberrant splicing in cancer, with a focus on serine/arginine-rich (SR) proteins and their recently reported roles in cancer development and progression and beyond. Recent mapping of the spliceosome, its associated splicing factors, and their relationship to cancer have opened the door to novel therapeutic approaches that capitalize on the widespread influence of alternative splicing. We conclude by discussing small molecule inhibitors of the spliceosome that have been identified in an evolving era of cancer treatment.
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Affiliation(s)
- Anthony J. Murphy
- Department of Environmental Medicine, New York University School of Medicine, New York, NY, United States
| | - Alex H. Li
- Department of Environmental Medicine, New York University School of Medicine, New York, NY, United States
| | - Peichao Li
- Department of Thoracic Surgery, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Hong Sun
- Department of Environmental Medicine, New York University School of Medicine, New York, NY, United States
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4
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Jia T, Jacquet T, Dalonneau F, Coudert P, Vaganay E, Exbrayat-Héritier C, Vollaire J, Josserand V, Ruggiero F, Coll JL, Eymin B. FGF-2 promotes angiogenesis through a SRSF1/SRSF3/SRPK1-dependent axis that controls VEGFR1 splicing in endothelial cells. BMC Biol 2021; 19:173. [PMID: 34433435 PMCID: PMC8390225 DOI: 10.1186/s12915-021-01103-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 07/16/2021] [Indexed: 02/07/2023] Open
Abstract
Background Angiogenesis is the process by which new blood vessels arise from pre-existing ones. Fibroblast growth factor-2 (FGF-2), a leading member of the FGF family of heparin-binding growth factors, contributes to normal as well as pathological angiogenesis. Pre-mRNA alternative splicing plays a key role in the regulation of cellular and tissular homeostasis and is highly controlled by splicing factors, including SRSFs. SRSFs belong to the SR protein family and are regulated by serine/threonine kinases such as SRPK1. Up to now, the role of SR proteins and their regulators in the biology of endothelial cells remains elusive, in particular upstream signals that control their expression. Results By combining 2D endothelial cells cultures, 3D collagen sprouting assay, a model of angiogenesis in cellulose sponges in mice and a model of angiogenesis in zebrafish, we collectively show that FGF-2 promotes proliferation, survival, and sprouting of endothelial cells by activating a SRSF1/SRSF3/SRPK1-dependent axis. In vitro, we further demonstrate that this FGF-2-dependent signaling pathway controls VEGFR1 pre-mRNA splicing and leads to the generation of soluble VEGFR1 splice variants, in particular a sVEGFR1-ex12 which retains an alternative last exon, that contribute to FGF-2-mediated angiogenic functions. Finally, we show that sVEGFR1-ex12 mRNA level correlates with that of FGF-2/FGFR1 in squamous lung carcinoma patients and that sVEGFR1-ex12 is a poor prognosis marker in these patients. Conclusions We demonstrate that FGF-2 promotes angiogenesis by activating a SRSF1/SRSF3/SRPK1 network that regulates VEGFR1 alternative splicing in endothelial cells, a process that could also contribute to lung tumor progression. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01103-3.
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Affiliation(s)
- Tao Jia
- Institute For Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Site Santé, Allée des Alpes, 38700, La Tronche, France.,Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu, 610041, China
| | - Thibault Jacquet
- Institute For Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Site Santé, Allée des Alpes, 38700, La Tronche, France
| | - Fabien Dalonneau
- Institute For Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Site Santé, Allée des Alpes, 38700, La Tronche, France
| | - Pauline Coudert
- Institut de Génomique Fonctionnelle de Lyon, ENS de Lyon, UMR CNRS 5242, Université Lyon 1, 46 Allée d'Italie, 69364, Lyon Cedex 07, France
| | - Elisabeth Vaganay
- Institut de Génomique Fonctionnelle de Lyon, ENS de Lyon, UMR CNRS 5242, Université Lyon 1, 46 Allée d'Italie, 69364, Lyon Cedex 07, France
| | - Chloé Exbrayat-Héritier
- Institut de Génomique Fonctionnelle de Lyon, ENS de Lyon, UMR CNRS 5242, Université Lyon 1, 46 Allée d'Italie, 69364, Lyon Cedex 07, France
| | - Julien Vollaire
- Institute For Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Site Santé, Allée des Alpes, 38700, La Tronche, France
| | - Véronique Josserand
- Institute For Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Site Santé, Allée des Alpes, 38700, La Tronche, France
| | - Florence Ruggiero
- Institut de Génomique Fonctionnelle de Lyon, ENS de Lyon, UMR CNRS 5242, Université Lyon 1, 46 Allée d'Italie, 69364, Lyon Cedex 07, France
| | - Jean-Luc Coll
- Institute For Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Site Santé, Allée des Alpes, 38700, La Tronche, France
| | - Béatrice Eymin
- Institute For Advanced Biosciences, INSERM U1209, CNRS UMR5309, Université Grenoble Alpes, Site Santé, Allée des Alpes, 38700, La Tronche, France.
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5
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Li Q, Zeng C, Liu H, Yung KWY, Chen C, Xie Q, Zhang Y, Wan SWC, Mak BSW, Xia J, Xiong S, Ngo JCK. Protein-Protein Interaction Inhibitor of SRPKs Alters the Splicing Isoforms of VEGF and Inhibits Angiogenesis. iScience 2021; 24:102423. [PMID: 33997701 PMCID: PMC8102418 DOI: 10.1016/j.isci.2021.102423] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 03/13/2021] [Accepted: 04/09/2021] [Indexed: 12/14/2022] Open
Abstract
Serine-arginine (SR) protein kinases (SRPKs) regulate the functions of the SR-rich splicing factors by phosphorylating multiple serines within their C-terminal arginine-serine-rich domains. Dysregulation of these phosphorylation events has been implicated in many diseases, suggesting SRPKs are potential therapeutic targets. In particular, aberrant SRPK1 expression alters the balances of proangiogenic (VEGF165) and antiangiogenic (VEGF165b) splicing isoforms of the key angiogenesis factor, vascular endothelial growth factor (VEGF), through the phosphorylation of prototypic SR protein SRSF1. Here, we report a protein-protein interaction (PPI) inhibitor of SRPKs, docking blocker of SRPK1 (DBS1), that specifically blocks a conserved substrate docking groove unique to SRPKs. DBS1 is a cell-permeable inhibitor that effectively inhibits the binding and phosphorylation of SRSF1 and subsequently switches VEGF splicing from the proangiogenic to the antiangiogenic isoform. Our findings thus provide a new direction for the development of SRPK inhibitors through targeting a unique PPI site to combat angiogenic diseases.
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Affiliation(s)
- Qingyun Li
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
- Hong Kong Branch of National Engineering Research Center of Genetic Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Chuyue Zeng
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Haizhen Liu
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Kristen Wing Yu Yung
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Chun Chen
- Department of Cellular Biology, Jinan University, Guangzhou, China
| | - Qiuling Xie
- Department of Cellular Biology, Jinan University, Guangzhou, China
| | - Yu Zhang
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Stephanie Winn Chee Wan
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Bertha Sze Wing Mak
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Jiang Xia
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Sheng Xiong
- Department of Cellular Biology, Jinan University, Guangzhou, China
- Hong Kong Branch of National Engineering Research Center of Genetic Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Jacky Chi Ki Ngo
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
- Hong Kong Branch of National Engineering Research Center of Genetic Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
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6
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Li K, Wang Z. Splicing factor SRSF2-centric gene regulation. Int J Biol Sci 2021; 17:1708-1715. [PMID: 33994855 PMCID: PMC8120470 DOI: 10.7150/ijbs.58888] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 04/04/2021] [Indexed: 01/14/2023] Open
Abstract
Serine/arginine-rich splicing factor 2 (SRSF2) is a splicing factor that is widely expressed in a variety of mammalian cell types. Increasing evidence has confirmed that SRSF2 plays vital roles in a number of biological and pathological processes. Therefore, it is important to understand how its expression is regulated, and how it regulates the expression of its target genes. Recently, we found that SRSF2 expression could be upregulated by herpes simplex virus-1 (HSV-1) infection, and that altered SRSF2 expression, in turn, epigenetically regulates the transcription of HSV-1 genes. Further studies on T cell exhaustion demonstrated that upregulated SRSF2 in exhausted T cells elevated the levels of multiple immune checkpoint molecules by associating with the acyl-transferases, P300 and CBP, and by altering histone modification near the transcription start sites of these genes, thereby influencing signal transducer and activator of transcription 3 binding to these gene promoters. These findings suggest that SRSF2 acts as an important sensor and effector during disease progression. Here, we discuss the molecules that regulate SRSF2 gene expression and their associated mechanisms, and the mechanisms via which SRSF2 regulates the expression of target genes, thus providing novel insights into the central role of SRSF2 in gene regulation.
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Affiliation(s)
- Kun Li
- Department of Nuclear Medicine, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan 250014, China
| | - Ziqiang Wang
- Department of Nuclear Medicine, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan 250014, China.,Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
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7
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Tekin V, Aweda T, Kozgus Guldu O, Biber Muftuler FZ, Bartels J, Lapi SE, Unak P. A novel anti-angiogenic radio/photo sensitizer for prostate cancer imaging and therapy: 89Zr-Pt@TiO 2-SPHINX, synthesis and in vitro evaluation. Nucl Med Biol 2021; 94-95:20-31. [PMID: 33482596 DOI: 10.1016/j.nucmedbio.2020.12.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 12/21/2020] [Accepted: 12/23/2020] [Indexed: 01/27/2023]
Abstract
Prostate cancer is the most common malignancy and leading cause of cancer deaths in men. Thus, the development of novel strategies for performing combined prostate cancer imaging and therapy methods is crucial and could have a significant impact on patient care. This current study aimed to design a multimodality nanoconjugate to be used for both PET and optical imaging and as a therapeutic radio/photo sensitizer and anti-angiogenesis agent. Initial characterization of this novel nanoconjugate was performed via HPLC, FTIR, TEM and DLS analyses. Pt@TiO2-SPHINX was further evaluated using fluorometric and radiochromatographic methods. Cytotoxicity, cell uptake and internalization were also investigated as well as therapy with photodynamic/radio therapy combinations. Both nanoparticles and nanoconjugates were robustly synthesized according to literature methods. Radiochemistry and cell culture assays showed high 89Zr radiolabeling efficiency with sufficient stability for studies at later time points. Pt@TiO2-SPHINX was shown to target prostate cancer cells (PC3 and LNCaP), and was non-toxic to normal prostate cells (RWPE-1). This finding was supported by the WST-8 assay and AFM images. The uptake of the compound in prostate cancer cells is significantly higher than prostate normal cells and according to ELISA results, Pt@TiO2-SPHINX can increase anti-angiogenic VEGFA165b. Additionally, Pt@TiO2-SPHINX dramatically decreased the cell viability of prostate cancer cells when photodynamic and radio therapy were performed at the same time. In vitro results are promising for future studies of Pt@TiO2-SPHINX as a PET imaging agent and anti-angiogenic radio sensitizer.
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Affiliation(s)
- Volkan Tekin
- Institute of Nuclear Science, Ege University, Izmir, Turkey.
| | - Tolulope Aweda
- Department of Radiology, University of Alabama at Birmingham, AL, United States of America
| | | | | | - Jennifer Bartels
- Department of Radiology, University of Alabama at Birmingham, AL, United States of America
| | - Suzanne E Lapi
- Department of Radiology, University of Alabama at Birmingham, AL, United States of America
| | - Perihan Unak
- Institute of Nuclear Science, Ege University, Izmir, Turkey
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8
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Du JX, Zhu GQ, Cai JL, Wang B, Luo YH, Chen C, Cai CZ, Zhang SJ, Zhou J, Fan J, Zhu W, Dai Z. Splicing factors: Insights into their regulatory network in alternative splicing in cancer. Cancer Lett 2020; 501:83-104. [PMID: 33309781 DOI: 10.1016/j.canlet.2020.11.043] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/24/2020] [Accepted: 11/26/2020] [Indexed: 12/18/2022]
Abstract
More than 95% of all human genes are alternatively spliced after transcription, which enriches the diversity of proteins and regulates transcript and/or protein levels. The splicing isoforms produced from the same gene can manifest distinctly, even exerting opposite effects. Mounting evidence indicates that the alternative splicing (AS) mechanism is ubiquitous in various cancers and drives the generation and maintenance of various hallmarks of cancer, such as enhanced proliferation, inhibited apoptosis, invasion and metastasis, and angiogenesis. Splicing factors (SFs) play pivotal roles in the recognition of splice sites and the assembly of spliceosomes during AS. In this review, we mainly discuss the similarities and differences of SF domains, the details of SF function in AS, the effect of SF-driven pathological AS on different hallmarks of cancer, and the main drivers of SF expression level and subcellular localization. In addition, we briefly introduce the application prospects of targeted therapeutic strategies, including small-molecule inhibitors, siRNAs and splice-switching oligonucleotides (SSOs), from three perspectives (drivers, SFs and pathological AS). Finally, we share our insights into the potential direction of research on SF-centric AS-related regulatory networks.
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Affiliation(s)
- Jun-Xian Du
- Department of General Surgery, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Gui-Qi Zhu
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China; Key Laboratory of Carcinogenesis and Cancer Invasion, Fudan University, Ministry of Education, Shanghai, 200032, China
| | - Jia-Liang Cai
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China; Key Laboratory of Carcinogenesis and Cancer Invasion, Fudan University, Ministry of Education, Shanghai, 200032, China
| | - Biao Wang
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China; Key Laboratory of Carcinogenesis and Cancer Invasion, Fudan University, Ministry of Education, Shanghai, 200032, China
| | - Yi-Hong Luo
- Department of General Surgery, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Cong Chen
- Department of General Surgery, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Cheng-Zhe Cai
- Department of General Surgery, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Si-Jia Zhang
- Department of General Surgery, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Jian Zhou
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China; Key Laboratory of Carcinogenesis and Cancer Invasion, Fudan University, Ministry of Education, Shanghai, 200032, China
| | - Jia Fan
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China; Key Laboratory of Carcinogenesis and Cancer Invasion, Fudan University, Ministry of Education, Shanghai, 200032, China
| | - Wei Zhu
- Department of General Surgery, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China.
| | - Zhi Dai
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China; Key Laboratory of Carcinogenesis and Cancer Invasion, Fudan University, Ministry of Education, Shanghai, 200032, China.
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9
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Dardente H, English WR, Valluru MK, Kanthou C, Simpson D. Debunking the Myth of the Endogenous Antiangiogenic Vegfaxxxb Transcripts. Trends Endocrinol Metab 2020; 31:398-409. [PMID: 32396842 DOI: 10.1016/j.tem.2020.01.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/28/2019] [Accepted: 01/14/2020] [Indexed: 12/19/2022]
Abstract
In this opinion article we critically assess evidence for the existence of a family of antiangiogenic vascular endothelial growth factor (Vegfaxxxb) transcripts, arising from the use of a phylogenetically conserved alternative distal splice site within exon 8 of the VEGFA gene. We explain that prior evidence for Vegfaxxxb transcripts in tissues rests heavily upon flawed RT-PCR methodologies, with the extensive use of 5'-tailing in primer design being the main issue. Furthermore, our analysis of large RNA-seq data sets (human and ovine) fails to identify a single Vegfaxxxb transcript. Therefore, we challenge the very existence of Vegfaxxxb transcripts, which further questions the physiological relevance of studies based on the use of 'anti-VEGFAxxxb' antibodies. Our analysis has implications for the proposed therapeutic use of isoform-specific anti-VEGFA strategies for treating cancer and retinopathies.
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Affiliation(s)
- Hugues Dardente
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380 Nouzilly, France.
| | - William R English
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - Manoj K Valluru
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - Chryso Kanthou
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - David Simpson
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, BT7 1NN, UK
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10
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An Intricate Connection between Alternative Splicing and Phenotypic Plasticity in Development and Cancer. Cells 2019; 9:cells9010034. [PMID: 31877720 PMCID: PMC7016785 DOI: 10.3390/cells9010034] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/10/2019] [Accepted: 12/18/2019] [Indexed: 12/12/2022] Open
Abstract
During tumor progression, hypoxia, nutrient deprivation or changes in the extracellular environment (i.e., induced by anti-cancer drugs) elicit adaptive responses in cancer cells. Cellular plasticity increases the chance that tumor cells may survive in a challenging microenvironment, acquire new mechanisms of resistance to conventional drugs, and spread to distant sites. Re-activation of stem pathways appears as a significant cause of cellular plasticity because it promotes the acquisition of stem-like properties through a profound phenotypic reprogramming of cancer cells. In addition, it is a major contributor to tumor heterogeneity, depending on the coexistence of phenotypically distinct subpopulations in the same tumor bulk. Several cellular mechanisms may drive this fundamental change, in particular, high-throughput sequencing technologies revealed a key role for alternative splicing (AS). Effectively, AS is one of the most important pre-mRNA processes that increases the diversity of transcriptome and proteome in a tissue- and development-dependent manner. Moreover, defective AS has been associated with several human diseases. However, its role in cancer cell plasticity and tumor heterogeneity remains unclear. Therefore, unravelling the intricate relationship between AS and the maintenance of a stem-like phenotype may explain molecular mechanisms underlying cancer cell plasticity and improve cancer diagnosis and treatment.
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11
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Mitochondria-targeted hydrogen sulfide attenuates endothelial senescence by selective induction of splicing factors HNRNPD and SRSF2. Aging (Albany NY) 2019; 10:1666-1681. [PMID: 30026406 PMCID: PMC6075431 DOI: 10.18632/aging.101500] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/15/2018] [Indexed: 12/13/2022]
Abstract
Cellular senescence is a key driver of ageing, influenced by age-related changes to the regulation of alternative splicing. Hydrogen sulfide (H2S) has similarly been described to influence senescence, but the pathways by which it accomplishes this are unclear.We assessed the effects of the slow release H2S donor Na-GYY4137 (100 µg/ml), and three novel mitochondria-targeted H2S donors AP39, AP123 and RT01 (10 ng/ml) on splicing factor expression, cell proliferation, apoptosis, DNA replication, DNA damage, telomere length and senescence-related secretory complex (SASP) expression in senescent primary human endothelial cells.All H2S donors produced up to a 50% drop in senescent cell load assessed at the biochemical and molecular level. Some changes were noted in the composition of senescence-related secretory complex (SASP); IL8 levels increased by 24% but proliferation was not re-established in the culture as a whole. Telomere length, apoptotic index and the extent of DNA damage were unaffected. Differential effects on splicing factor expression were observed depending on the intracellular targeting of the H2S donors. Na-GYY4137 produced a general 1.9 - 3.2-fold upregulation of splicing factor expression, whereas the mitochondria-targeted donors produced a specific 2.5 and 3.1-fold upregulation of SRSF2 and HNRNPD splicing factors only. Knockdown of SRSF2 or HNRNPD genes in treated cells rendered the cells non-responsive to H2S, and increased levels of senescence by up to 25% in untreated cells.Our data suggest that SRSF2 and HNRNPD may be implicated in endothelial cell senescence, and can be targeted by exogenous H2S. These molecules may have potential as moderators of splicing factor expression and senescence phenotypes.
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12
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Bowler E, Oltean S. Alternative Splicing in Angiogenesis. Int J Mol Sci 2019; 20:E2067. [PMID: 31027366 PMCID: PMC6540211 DOI: 10.3390/ijms20092067] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/15/2019] [Accepted: 04/23/2019] [Indexed: 12/12/2022] Open
Abstract
Alternative splicing of pre-mRNA allows the generation of multiple splice isoforms from a given gene, which can have distinct functions. In fact, splice isoforms can have opposing functions and there are many instances whereby a splice isoform acts as an inhibitor of canonical isoform function, thereby adding an additional layer of regulation to important processes. Angiogenesis is an important process that is governed by alternative splicing mechanisms. This review focuses on the alternative spliced isoforms of key genes that are involved in the angiogenesis process; VEGF-A, VEGFR1, VEGFR2, NRP-1, FGFRs, Vasohibin-1, Vasohibin-2, HIF-1α, Angiopoietin-1 and Angiopoietin-2.
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Affiliation(s)
- Elizabeth Bowler
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, Exeter EX4 4PY, UK.
| | - Sebastian Oltean
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, Exeter EX4 4PY, UK.
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13
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Modulation of Receptor Tyrosine Kinase Activity through Alternative Splicing of Ligands and Receptors in the VEGF-A/VEGFR Axis. Cells 2019; 8:cells8040288. [PMID: 30925751 PMCID: PMC6523102 DOI: 10.3390/cells8040288] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 03/19/2019] [Accepted: 03/22/2019] [Indexed: 12/14/2022] Open
Abstract
Vascular endothelial growth factor A (VEGF-A) signaling is essential for physiological and pathological angiogenesis. Alternative splicing of the VEGF-A pre-mRNA gives rise to a pro-angiogenic family of isoforms with a differing number of amino acids (VEGF-Axxxa), as well as a family of isoforms with anti-angiogenic properties (VEGF-Axxxb). The biological functions of VEGF-A proteins are mediated by a family of cognate protein tyrosine kinase receptors, known as the VEGF receptors (VEGFRs). VEGF-A binds to both VEGFR-1, largely suggested to function as a decoy receptor, and VEGFR-2, the predominant signaling receptor. Both VEGFR-1 and VEGFR-2 can also be alternatively spliced to generate soluble isoforms (sVEGFR-1/sVEGFR-2). The disruption of the splicing of just one of these genes can result in changes to the entire VEGF-A/VEGFR signaling axis, such as the increase in VEGF-A165a relative to VEGF-A165b resulting in increased VEGFR-2 signaling and aberrant angiogenesis in cancer. Research into this signaling axis has recently focused on manipulating the splicing of these genes as a potential therapeutic avenue in disease. Therefore, further research into understanding the mechanisms by which the splicing of VEGF-A/VEGFR-1/VEGFR-2 is regulated will help in the development of drugs aimed at manipulating splicing or inhibiting specific splice isoforms in a therapeutic manner.
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14
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Kikuchi R, Stevens M, Harada K, Oltean S, Murohara T. Anti-angiogenic isoform of vascular endothelial growth factor-A in cardiovascular and renal disease. Adv Clin Chem 2019; 88:1-33. [PMID: 30612603 DOI: 10.1016/bs.acc.2018.10.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Accumulating evidence suggests that pathologic interactions between the heart and the kidney can contribute to the progressive dysfunction of both organs. Recently, there has been an increase in the prevalence of cardiovascular disease (CVD) and chronic kidney disease (CKD) due to increasing obesity rates. It has been reported that obesity causes various heart and renal disorders and appears to accelerate their progression. Vascular endothelial growth factor-A (VEGF-A) is a major regulator of angiogenesis and vessel permeability, and is associated with CVD and CKD. It is now recognized that alternative VEGF-A gene splicing generates VEGF-A isoforms that differ in their biological actions. Proximal splicing that includes an exon 8a sequence results in pro-angiogenic VEGF-A165a, whereas distal splicing inclusive of exon 8b yields the anti-angiogenic isoform of VEGF-A (VEGF-A165b). This review highlights several recent preclinical and clinical studies on the role of VEGF-A165b in CVD and CKD as a novel function of VEGF-A. This review also discusses potential therapeutic approaches of the use of VEGF-A in clinical settings as a potential circulating biomarker for CVD and CKD.
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Affiliation(s)
- Ryosuke Kikuchi
- Department of Medical Technique, Nagoya University Hospital, Nagoya, Japan.
| | - Megan Stevens
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom
| | - Kazuhiro Harada
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Sebastian Oltean
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom
| | - Toyoaki Murohara
- Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
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15
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Lee SD, Yu D, Lee DY, Shin HS, Jo JH, Lee YC. Upregulated microRNA-193a-3p is responsible for cisplatin resistance in CD44(+) gastric cancer cells. Cancer Sci 2018; 110:662-673. [PMID: 30485589 PMCID: PMC6361556 DOI: 10.1111/cas.13894] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/21/2018] [Accepted: 11/26/2018] [Indexed: 12/17/2022] Open
Abstract
Cisplatin is a well‐known anticancer drug used to treat various cancers. However, development of cisplatin resistance has hindered the efficiency of this drug in cancer treatment. Development of chemoresistance is known to involve many signaling pathways. Recent attention has focused on microRNAs (miRNAs) as potentially important upstream regulators in the development of chemoresistance. CD44 is one of the gastric cancer stem cell markers and plays a role in regulating self‐renewal, tumor initiation, metastasis and chemoresistance. The purpose of the present study was to examine the mechanism of miRNA‐mediated chemoresistance to cisplatin in CD44‐positive gastric cancer stem cells. We sorted gastric cancer cells according to level of CD44 expression by FACS and analyzed their miRNA expression profiles by microarray analysis. We found that miR‐193a‐3p was significantly upregulated in CD44(+) cells compared with CD44(−) cells. Moreover, SRSF2 of miR‐193a‐3p target gene was downregulated in CD44(+) cells. We studied the modulation of Bcl‐X and caspase 9 mRNA splicing by SRSF2 and found that more pro‐apoptotic variants of these genes were generated. We also found that downstream anti‐apoptotic genes such as Bcl‐2 were upregulated, whereas pro‐apoptotic genes such as Bax and cytochrome C were downregulated in CD44(+) cells compared to CD44(−) cells. In addition, we found that an elevated level of miR‐193a‐3p triggered the development of cisplatin resistance in CD44(+) cells. Inhibition of miR‐193a‐3p in CD44(+) cells increased SRSF2 expression and also altered the levels of multiple apoptotic genes. Furthermore, inhibition of miR‐193a‐3p reduced cell viability and increased the number of apoptotic cells. Therefore, miR‐193a‐3p may be implicated in the development of cisplatin resistance through regulation of the mitochondrial apoptosis pathway. miR‐193a‐3p could be a promising target for cancer therapy in cisplatin‐resistant gastric cancer.
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Affiliation(s)
- So D Lee
- Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea
| | - Dayeon Yu
- Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Do Y Lee
- Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea
| | - Hyun-Soo Shin
- Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea
| | - Jeong-Hyeon Jo
- Department of Pathology, Yonsei University College of Medicine, Seoul, Korea
| | - Yong C Lee
- Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
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16
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Boudria A, Abou Faycal C, Jia T, Gout S, Keramidas M, Didier C, Lemaître N, Manet S, Coll JL, Toffart AC, Moro-Sibilot D, Albiges-Rizo C, Josserand V, Faurobert E, Brambilla C, Brambilla E, Gazzeri S, Eymin B. VEGF 165b, a splice variant of VEGF-A, promotes lung tumor progression and escape from anti-angiogenic therapies through a β1 integrin/VEGFR autocrine loop. Oncogene 2018; 38:1050-1066. [PMID: 30194450 DOI: 10.1038/s41388-018-0486-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 06/25/2018] [Accepted: 07/29/2018] [Indexed: 12/21/2022]
Abstract
Vascular endothelial growth factor-A (VEGF-A) is highly subjected to alternative pre-mRNA splicing that generates several splice variants. The VEGFxxx and VEGFxxxb families encode splice variants of VEGF-A that differ only at the level of six amino acids in their C-terminal part. The expression level of VEGFxxx splice variants and their function as pro-angiogenic factors during tumor neo-angiogenesis have been well-described. The role of VEGFxxxb isoforms is less well known, but they have been shown to inhibit VEGFxxx-mediated angiogenesis, while being partial or weak activators of VEGFR receptors in endothelial cells. On the opposite, their role on tumor cells expressing VEGFRs at their surface remains largely unknown. In this study, we find elevated levels of VEGF165b, the main VEGFxxxb isoform, in 36% of non-small cell lung carcinoma (NSCLC), mainly lung adenocarcinoma (46%), and show that a high VEGF165b/VEGF165 ratio correlates with the presence of lymph node metastases. At the molecular level, we demonstrate that VEGF165b stimulates proliferation and invasiveness of two lung tumor cell lines through a VEGFR/β1 integrin loop. We further provide evidence that the isoform-specific knockdown of VEGF165b reduces tumor growth, demonstrating a tumor-promoting autocrine role for VEGF165b in lung cancer cells. Importantly, we show that bevacizumab, an anti-angiogenic compound used for the treatment of lung adenocarcinoma patients, increases the expression of VEGF165b and activates the invasive VEGFR/β1 integrin loop. Overall, these data highlight an unexpected role of the VEGF165b splice variant in the progression of lung tumors and their response to anti-angiogenic therapies.
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Affiliation(s)
- Asma Boudria
- INSERM U1209, UMR CNRS 5309, Team RNA splicing, Cell Signaling and Response to Therapies, Grenoble, 38042, France.,Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France
| | - Cherine Abou Faycal
- INSERM U1209, UMR CNRS 5309, Team RNA splicing, Cell Signaling and Response to Therapies, Grenoble, 38042, France.,Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France
| | - Tao Jia
- INSERM U1209, UMR CNRS 5309, Team RNA splicing, Cell Signaling and Response to Therapies, Grenoble, 38042, France.,Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France
| | - Stephanie Gout
- INSERM U1209, UMR CNRS 5309, Team RNA splicing, Cell Signaling and Response to Therapies, Grenoble, 38042, France.,Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France
| | - Michelle Keramidas
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM, U1209, UMR CNRS 5309, Team Cancer Targets and Experimental Therapeutics, Grenoble, 38042, France
| | - Chloé Didier
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM, U1209, UMR CNRS 5309, Team Cancer Targets and Experimental Therapeutics, Grenoble, 38042, France
| | - Nicolas Lemaître
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Tumor Molecular Pathology and Biomarkers, Grenoble, 38042, France
| | - Sandra Manet
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Cell Adhesion Dynamics and Differentiation, Grenoble, 38042, France
| | - Jean-Luc Coll
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM, U1209, UMR CNRS 5309, Team Cancer Targets and Experimental Therapeutics, Grenoble, 38042, France
| | - Anne-Claire Toffart
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Tumor Molecular Pathology and Biomarkers, Grenoble, 38042, France
| | - Denis Moro-Sibilot
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Tumor Molecular Pathology and Biomarkers, Grenoble, 38042, France
| | - Corinne Albiges-Rizo
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Cell Adhesion Dynamics and Differentiation, Grenoble, 38042, France
| | - Véronique Josserand
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM, U1209, UMR CNRS 5309, Team Cancer Targets and Experimental Therapeutics, Grenoble, 38042, France
| | - Eva Faurobert
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Cell Adhesion Dynamics and Differentiation, Grenoble, 38042, France
| | - Christian Brambilla
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Tumor Molecular Pathology and Biomarkers, Grenoble, 38042, France
| | - Elisabeth Brambilla
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Tumor Molecular Pathology and Biomarkers, Grenoble, 38042, France
| | - Sylvie Gazzeri
- INSERM U1209, UMR CNRS 5309, Team RNA splicing, Cell Signaling and Response to Therapies, Grenoble, 38042, France.,Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France
| | - Beatrice Eymin
- INSERM U1209, UMR CNRS 5309, Team RNA splicing, Cell Signaling and Response to Therapies, Grenoble, 38042, France. .,Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.
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17
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Bates DO, Beazley-Long N, Benest AV, Ye X, Ved N, Hulse RP, Barratt S, Machado MJ, Donaldson LF, Harper SJ, Peiris-Pages M, Tortonese DJ, Oltean S, Foster RR. Physiological Role of Vascular Endothelial Growth Factors as Homeostatic Regulators. Compr Physiol 2018; 8:955-979. [PMID: 29978898 DOI: 10.1002/cphy.c170015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The vascular endothelial growth factor (VEGF) family of proteins are key regulators of physiological systems. Originally linked with endothelial function, they have since become understood to be principal regulators of multiple tissues, both through their actions on vascular cells, but also through direct actions on other tissue types, including epithelial cells, neurons, and the immune system. The complexity of the five members of the gene family in terms of their different splice isoforms, differential translation, and specific localizations have enabled tissues to use these potent signaling molecules to control how they function to maintain their environment. This homeostatic function of VEGFs has been less intensely studied than their involvement in disease processes, development, and reproduction, but they still play a substantial and significant role in healthy control of blood volume and pressure, interstitial volume and drainage, renal and lung function, immunity, and signal processing in the peripheral and central nervous system. The widespread expression of VEGFs in healthy adult tissues, and the disturbances seen when VEGF signaling is inhibited support this view of the proteins as endogenous regulators of normal physiological function. This review summarizes the evidence and recent breakthroughs in understanding of the physiology that is regulated by VEGF, with emphasis on the role they play in maintaining homeostasis. © 2017 American Physiological Society. Compr Physiol 8:955-979, 2018.
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Affiliation(s)
- David O Bates
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | | | - Andrew V Benest
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Xi Ye
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Nikita Ved
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Richard P Hulse
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Shaney Barratt
- Academic Respiratory Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Maria J Machado
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Lucy F Donaldson
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Steven J Harper
- School of Physiology, Pharmacology & Neuroscience, Medical School, University of Bristol, Bristol, United Kingdom
| | - Maria Peiris-Pages
- Cancer Research UK Manchester Institute, The University of Manchester, Manchester, United Kingdom
| | - Domingo J Tortonese
- Centre for Comparative and Clinical Anatomy, University of Bristol, Bristol, United Kingdom
| | - Sebastian Oltean
- Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, United Kingdom
| | - Rebecca R Foster
- Bristol Renal, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
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18
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Antonopoulou E, Ladomery M. Targeting Splicing in Prostate Cancer. Int J Mol Sci 2018; 19:ijms19051287. [PMID: 29693622 PMCID: PMC5983716 DOI: 10.3390/ijms19051287] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/18/2018] [Accepted: 04/23/2018] [Indexed: 12/22/2022] Open
Abstract
Over 95% of human genes are alternatively spliced, expressing splice isoforms that often exhibit antagonistic functions. We describe genes whose alternative splicing has been linked to prostate cancer; namely VEGFA, KLF6, BCL2L2, ERG, and AR. We discuss opportunities to develop novel therapies that target specific splice isoforms, or that target the machinery of splicing. Therapeutic approaches include the development of small molecule inhibitors of splice factor kinases, splice isoform specific siRNAs, and splice switching oligonucleotides.
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Affiliation(s)
- Effrosyni Antonopoulou
- Faculty of Health and Applied Sciences, University of the West of England, Coldharbour Lane, Bristol BS16 1QY, UK.
| | - Michael Ladomery
- Faculty of Health and Applied Sciences, University of the West of England, Coldharbour Lane, Bristol BS16 1QY, UK.
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19
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Kolshus E, Ryan KM, Blackshields G, Smyth P, Sheils O, McLoughlin DM. Peripheral blood microRNA and VEGFA mRNA changes following electroconvulsive therapy: implications for psychotic depression. Acta Psychiatr Scand 2017; 136:594-606. [PMID: 28975998 DOI: 10.1111/acps.12821] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/18/2017] [Indexed: 12/26/2022]
Abstract
OBJECTIVE MicroRNAs are short, non-coding molecules that regulate gene expression. Here, we investigate the role of microRNAs in depression and electroconvulsive therapy (ECT). METHODS We performed three studies: a deep sequencing discovery-phase study of miRNA changes in whole blood following ECT (n = 16), followed by a validation study in a separate cohort of patients pre-/post-ECT (n = 37) and matched healthy controls (n = 34). Changes in an experimentally validated gene target (VEGFA) were then analysed in patients pre-/post-ECT (n = 97) and in matched healthy controls (n = 53). RESULTS In the discovery-phase study, we found no statistically significant differences in miRNA expression from baseline to end of treatment in the group as a whole, but post hoc analysis indicated a difference in patients with psychotic depression (n = 3). In a follow-up validation study, patients with psychotic depression (n = 7) had elevated baseline levels of miR-126-3p (t = 3.015, P = 0.006) and miR-106a-5p (t = 2.598, P = 0.025) compared to healthy controls. Following ECT, these differences disappeared. Baseline VEGFA levels were significantly higher in depressed patients compared to healthy controls (F(1,144) = 27.688, P = <0.001). Following ECT, there was a significant change in VEGFA levels in the psychotic group only (t = 2.915, P = 0.010). CONCLUSION Molecular differences (miRNA and VEGFA) may exist between psychotic and non-psychotic depression treated with ECT.
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Affiliation(s)
- E Kolshus
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland.,Department of Psychiatry, Trinity College Dublin, St Patrick's University Hospital, Dublin 8, Ireland
| | - K M Ryan
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland.,Department of Psychiatry, Trinity College Dublin, St Patrick's University Hospital, Dublin 8, Ireland
| | - G Blackshields
- Department of Histopathology, Trinity College Dublin, St James's Hospital, Dublin 8, Ireland
| | - P Smyth
- Department of Histopathology, Trinity College Dublin, St James's Hospital, Dublin 8, Ireland
| | - O Sheils
- Department of Histopathology, Trinity College Dublin, St James's Hospital, Dublin 8, Ireland
| | - D M McLoughlin
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland.,Department of Psychiatry, Trinity College Dublin, St Patrick's University Hospital, Dublin 8, Ireland
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20
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Atypical E2Fs inhibit tumor angiogenesis. Oncogene 2017; 37:271-276. [PMID: 28925392 PMCID: PMC5770600 DOI: 10.1038/onc.2017.336] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 07/11/2017] [Accepted: 07/11/2017] [Indexed: 12/15/2022]
Abstract
Atypical E2F transcription factors (E2F7 and E2F8) function as key regulators of cell cycle progression and their inactivation leads to spontaneous cancer formation in mice. However, the mechanism of the tumor suppressor functions of E2F7/8 remain obscure. In this study we discovered that atypical E2Fs control tumor angiogenesis, one of the hallmarks of cancer. We genetically inactivated atypical E2Fs in epithelial and mesenchymal neoplasm and analyzed blood vessel formation in three different animal models of cancer. Tumor formation was either induced by application of 7,12-Dimethylbenz(a)anthracene/12-O-Tetradecanoylphorbol-13-acetate or by Myc/Ras overexpression. To our surprise, atypical E2Fs suppressed tumor angiogenesis in all three cancer models, which is in a sharp contrast to previous findings showing that atypical E2Fs promote angiogenesis during fetal development in mice and zebrafish. Real-time imaging in zebrafish displayed that fluorescent-labeled blood vessels showed enhanced intratumoral branching in xenografted E2f7/8-deficient neoplasms compared with E2f7/8-proficient neoplasms. DLL4 expression, a key negative inhibitor of vascular branching, was decreased in E2f7/8-deficient neoplastic cells, indicating that E2F7/8 might inhibit intratumoral vessel branching via induction of DLL4.
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21
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Bates DO, Morris JC, Oltean S, Donaldson LF. Pharmacology of Modulators of Alternative Splicing. Pharmacol Rev 2017; 69:63-79. [PMID: 28034912 PMCID: PMC5226212 DOI: 10.1124/pr.115.011239] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
More than 95% of genes in the human genome are alternatively spliced to form multiple transcripts, often encoding proteins with differing or opposing function. The control of alternative splicing is now being elucidated, and with this comes the opportunity to develop modulators of alternative splicing that can control cellular function. A number of approaches have been taken to develop compounds that can experimentally, and sometimes clinically, affect splicing control, resulting in potential novel therapeutics. Here we develop the concepts that targeting alternative splicing can result in relatively specific pathway inhibitors/activators that result in dampening down of physiologic or pathologic processes, from changes in muscle physiology to altering angiogenesis or pain. The targets and pharmacology of some of the current inhibitors/activators of alternative splicing are demonstrated and future directions discussed.
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Affiliation(s)
- David O Bates
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (D.O.B.); School of Chemistry, UNSW Australia, Sydney, Australia (J.C.M.); School of Physiology, Pharmacology and Neurosciences, School of Clinical Sciences/Bristol Renal, University of Bristol, Bristol, United Kingdom (S.O.); and School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (L.F.D.)
| | - Jonathan C Morris
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (D.O.B.); School of Chemistry, UNSW Australia, Sydney, Australia (J.C.M.); School of Physiology, Pharmacology and Neurosciences, School of Clinical Sciences/Bristol Renal, University of Bristol, Bristol, United Kingdom (S.O.); and School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (L.F.D.)
| | - Sebastian Oltean
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (D.O.B.); School of Chemistry, UNSW Australia, Sydney, Australia (J.C.M.); School of Physiology, Pharmacology and Neurosciences, School of Clinical Sciences/Bristol Renal, University of Bristol, Bristol, United Kingdom (S.O.); and School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (L.F.D.)
| | - Lucy F Donaldson
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (D.O.B.); School of Chemistry, UNSW Australia, Sydney, Australia (J.C.M.); School of Physiology, Pharmacology and Neurosciences, School of Clinical Sciences/Bristol Renal, University of Bristol, Bristol, United Kingdom (S.O.); and School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (L.F.D.)
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22
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Ye X, Abou-Rayyah Y, Bischoff J, Ritchie A, Sebire NJ, Watts P, Churchill AJ, Bates DO. Altered ratios of pro- and anti-angiogenic VEGF-A variants and pericyte expression of DLL4 disrupt vascular maturation in infantile haemangioma. J Pathol 2017; 239:139-51. [PMID: 26957058 PMCID: PMC4869683 DOI: 10.1002/path.4715] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 02/27/2016] [Accepted: 03/03/2016] [Indexed: 12/26/2022]
Abstract
Infantile haemangioma (IH), the most common neoplasm in infants, is a slowly resolving vascular tumour. Vascular endothelial growth factor A (VEGF‐A), which consists of both the pro‐ and anti‐angiogenic variants, contributes to the pathogenesis of IH. However, the roles of different VEGF‐A variants in IH progression and its spontaneous involution is unknown. Using patient‐derived cells and surgical specimens, we showed that the relative level of VEGF‐A165b was increased in the involuting phase of IH and the relative change in VEGF‐A isoforms may be dependent on endothelial differentiation of IH stem cells. VEGFR signalling regulated IH cell functions and VEGF‐A165b inhibited cell proliferation and the angiogenic potential of IH endothelial cells in vitro and in vivo. The inhibition of angiogenesis by VEGF‐A165b was associated with the extent of VEGF receptor 2 (VEGFR2) activation and degradation and Delta‐like ligand 4 (DLL4) expression. These results indicate that VEGF‐A variants can be regulated by cell differentiation and are involved in IH progression. We also demonstrated that DLL4 expression was not exclusive to the endothelium in IH but was also present in pericytes, where the expression of VEGFR2 is absent, suggesting that pericyte‐derived DLL4 may prevent sprouting during involution, independently of VEGFR2. Angiogenesis in IH therefore appears to be controlled by DLL4 within the endothelium in a VEGF‐A isoform‐dependent manner, and in perivascular cells in a VEGF‐independent manner. The contribution of VEGF‐A isoforms to disease progression also indicates that IH may be associated with altered splicing. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Xi Ye
- Ophthalmology Unit, School of Clinical Sciences, University of Bristol, UK.,Cancer Biology Unit, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, UK
| | | | - Joyce Bischoff
- Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, MA, USA
| | - Alison Ritchie
- Cancer Biology Unit, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, UK
| | - Neil J Sebire
- Histopathology, Great Ormond Street Hospital, London, UK
| | | | - Amanda J Churchill
- Ophthalmology Unit, School of Clinical Sciences, University of Bristol, UK
| | - David O Bates
- Cancer Biology Unit, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, UK
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23
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Czubaty A, Piekiełko-Witkowska A. Protein kinases that phosphorylate splicing factors: Roles in cancer development, progression and possible therapeutic options. Int J Biochem Cell Biol 2017; 91:102-115. [PMID: 28552434 DOI: 10.1016/j.biocel.2017.05.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/16/2017] [Accepted: 05/18/2017] [Indexed: 11/30/2022]
Abstract
Disturbed alternative splicing is a common feature of human tumors. Splicing factors that control alternative splicing are phosphorylated by multiple kinases, including these that specifically add phosphoryl groups to serine-arginine rich proteins (e.g. SR-protein kinases, cdc2-like kinases, topoisomerase 1), and protein kinases that govern key cellular signaling pathways (i.e. AKT). Phosphorylation of splicing factors regulates their subcellular localization and interactions with target transcripts and protein partners, and thus significantly contributes the final result of splicing reactions. In this review we aim to summarize the current knowledge on the role of splicing kinases in cancer. Published studies and recently released data of The Cancer Genome Atlas demonstrate that expressions and activities of splicing kinases are commonly disturbed in cancers. Aberrant functioning of splicing kinases results in changed alternative splicing of tumor suppressors (e.g. p53) and regulators of cell signaling (e.g. MAPKs), apoptosis (e.g. MCL), and angiogenesis (VEGF). Splicing kinases act in complicated regulatory networks in which they mutually affect each other's activity to provide tight control of cellular signaling. Dysregulation of these regulatory networks contributes to oncogenic transformation, uncontrolled proliferation, enhanced migration and invasion. Furthermore, the activities of splicing kinases significantly contribute to cellular responses to genotoxic stress. In conclusion, published data provide strong evidence that splicing kinases emerge as important regulators of key processes governing malignant transformation, progression, and response to therapeutic treatments, suggesting their potential as clinically relevant targets.
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Affiliation(s)
- Alicja Czubaty
- Department of Molecular Biology, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096 Warsaw, Poland
| | - Agnieszka Piekiełko-Witkowska
- Department of Biochemistry and Molecular Biology, Centre of Postgraduate Medical Education, ul. Marymoncka 99/103, 01-813 Warsaw, Poland.
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24
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Avior Y, Lezmi E, Yanuka D, Benvenisty N. Modeling Developmental and Tumorigenic Aspects of Trilateral Retinoblastoma via Human Embryonic Stem Cells. Stem Cell Reports 2017; 8:1354-1365. [PMID: 28392220 PMCID: PMC5425613 DOI: 10.1016/j.stemcr.2017.03.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 03/06/2017] [Accepted: 03/07/2017] [Indexed: 12/18/2022] Open
Abstract
Human embryonic stem cells (hESCs) provide a platform for studying human development and understanding mechanisms underlying diseases. Retinoblastoma-1 (RB1) is a key regulator of cell cycling, of which biallelic inactivation initiates retinoblastoma, the most common congenital intraocular malignancy. We developed a model to study the role of RB1 in early development and tumor formation by generating RB1-null hESCs using CRISPR/Cas9. RB1−/− hESCs initiated extremely large teratomas, with neural expansions similar to those of trilateral retinoblastoma tumors, in which retinoblastoma is accompanied by intracranial neural tumors. Teratoma analysis further revealed a role for the transcription factor ZEB1 in RB1-mediated ectoderm differentiation. Furthermore, RB1−/− cells displayed mitochondrial dysfunction similar to poorly differentiated retinoblastomas. Screening more than 100 chemotherapies revealed an RB1–/–-specific cell sensitivity to carboplatin, exploiting their mitochondrial dysfunction. Together, our work provides a human pluripotent cell model for retinoblastoma and sheds light on developmental and tumorigenic roles of RB1. RB1-null hESCs were generated using CRISPR/Cas9 RB1−/− hESCs generate large, neural-enriched teratomas, possibly by ZEB1 activation RB1 inactivation triggers aberrant mitochondrial abundance and function Unbiased drug screening found that carboplatin specifically targets RB1-null cells
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Affiliation(s)
- Yishai Avior
- The Azrieli Center for Stem Cells and Genetic Research, Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904, Israel
| | - Elyad Lezmi
- The Azrieli Center for Stem Cells and Genetic Research, Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904, Israel
| | - Dorit Yanuka
- The Azrieli Center for Stem Cells and Genetic Research, Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904, Israel
| | - Nissim Benvenisty
- The Azrieli Center for Stem Cells and Genetic Research, Institute of Life Sciences, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904, Israel.
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25
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Batson J, Toop HD, Redondo C, Babaei-Jadidi R, Chaikuad A, Wearmouth SF, Gibbons B, Allen C, Tallant C, Zhang J, Du C, Hancox JC, Hawtrey T, Da Rocha J, Griffith R, Knapp S, Bates DO, Morris JC. Development of Potent, Selective SRPK1 Inhibitors as Potential Topical Therapeutics for Neovascular Eye Disease. ACS Chem Biol 2017; 12:825-832. [PMID: 28135068 DOI: 10.1021/acschembio.6b01048] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Serine/arginine-protein kinase 1 (SRPK1) regulates alternative splicing of VEGF-A to pro-angiogenic isoforms and SRPK1 inhibition can restore the balance of pro/antiangiogenic isoforms to normal physiological levels. The lack of potency and selectivity of available compounds has limited development of SRPK1 inhibitors, with the control of alternative splicing by splicing factor-specific kinases yet to be translated. We present here compounds that occupy a binding pocket created by the unique helical insert of SRPK1, and trigger a backbone flip in the hinge region, that results in potent (<10 nM) and selective inhibition of SRPK1 kinase activity. Treatment with these inhibitors inhibited SRPK1 activity and phosphorylation of serine/arginine splicing factor 1 (SRSF1), resulting in alternative splicing of VEGF-A from pro-angiogenic to antiangiogenic isoforms. This property resulted in potent inhibition of blood vessel growth in models of choroidal angiogenesis in vivo. This work identifies tool compounds for splice isoform selective targeting of pro-angiogenic VEGF, which may lead to new therapeutic strategies for a diversity of diseases where dysfunctional splicing drives disease development.
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Affiliation(s)
- Jennifer Batson
- Exonate Ltd, Unit 23, Cambridge
Science Park, Cambridge, United Kingdom
- Cancer
Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen’s Medical Centre, Nottingham NG2 7UH, United Kingdom
| | - Hamish D. Toop
- Exonate Ltd, Unit 23, Cambridge
Science Park, Cambridge, United Kingdom
- School
of Chemistry, UNSW Australia, Sydney, Australia
| | - Clara Redondo
- Structural
Genomic Consortium, University of Oxford, Old Road Campus, Oxford OX3 7DQ, United Kingdom
| | - Roya Babaei-Jadidi
- Cancer
Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen’s Medical Centre, Nottingham NG2 7UH, United Kingdom
| | - Apirat Chaikuad
- Structural
Genomic Consortium, University of Oxford, Old Road Campus, Oxford OX3 7DQ, United Kingdom
- Institute
for Pharmaceutical Chemistry and Buchmann Institute for Life Sciences, Johann Wolfgang Goethe-University, D-60438, Frankfurt am Main, Germany
| | | | - Brian Gibbons
- Exonate Ltd, Unit 23, Cambridge
Science Park, Cambridge, United Kingdom
| | - Claire Allen
- Cancer
Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen’s Medical Centre, Nottingham NG2 7UH, United Kingdom
| | - Cynthia Tallant
- Structural
Genomic Consortium, University of Oxford, Old Road Campus, Oxford OX3 7DQ, United Kingdom
| | - Jingxue Zhang
- School
of Chemistry, UNSW Australia, Sydney, Australia
| | - Chunyun Du
- School
of Physiology and Pharmacology and Neuroscience, University of Bristol, BS8 1TD, Bristol, United Kingdom
| | - Jules C. Hancox
- School
of Physiology and Pharmacology and Neuroscience, University of Bristol, BS8 1TD, Bristol, United Kingdom
| | - Tom Hawtrey
- School
of Chemistry, UNSW Australia, Sydney, Australia
| | | | - Renate Griffith
- School
of
Medical Sciences, UNSW Australia, Sydney, Australia
| | - Stefan Knapp
- Structural
Genomic Consortium, University of Oxford, Old Road Campus, Oxford OX3 7DQ, United Kingdom
- Institute
for Pharmaceutical Chemistry and Buchmann Institute for Life Sciences, Johann Wolfgang Goethe-University, D-60438, Frankfurt am Main, Germany
| | - David O. Bates
- Exonate Ltd, Unit 23, Cambridge
Science Park, Cambridge, United Kingdom
- Cancer
Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen’s Medical Centre, Nottingham NG2 7UH, United Kingdom
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26
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Cai Y, Nogales-Cadenas R, Zhang Q, Lin JR, Zhang W, O’Brien K, Montagna C, Zhang ZD. Transcriptomic dynamics of breast cancer progression in the MMTV-PyMT mouse model. BMC Genomics 2017; 18:185. [PMID: 28212608 PMCID: PMC5316186 DOI: 10.1186/s12864-017-3563-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 02/07/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Malignant breast cancer with complex molecular mechanisms of progression and metastasis remains a leading cause of death in women. To improve diagnosis and drug development, it is critical to identify panels of genes and molecular pathways involved in tumor progression and malignant transition. Using the PyMT mouse, a genetically engineered mouse model that has been widely used to study human breast cancer, we profiled and analyzed gene expression from four distinct stages of tumor progression (hyperplasia, adenoma/MIN, early carcinoma and late carcinoma) during which malignant transition occurs. RESULTS We found remarkable expression similarity among the four stages, meaning genes altered in the later stages showed trace in the beginning of tumor progression. We identified a large number of differentially expressed genes in PyMT samples of all stages compared with normal mammary glands, enriched in cancer-related pathways. Using co-expression networks, we found panels of genes as signature modules with some hub genes that predict metastatic risk. Time-course analysis revealed genes with expression transition when shifting to malignant stages. These may provide additional insight into the molecular mechanisms beyond pathways. CONCLUSIONS Thus, in this study, our various analyses with the PyMT mouse model shed new light on transcriptomic dynamics during breast cancer malignant progression.
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Affiliation(s)
- Ying Cai
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY USA
| | | | - Quanwei Zhang
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY USA
| | - Jhih-Rong Lin
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY USA
| | - Wen Zhang
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY USA
| | - Kelly O’Brien
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY USA
| | - Cristina Montagna
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY USA
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY USA
| | - Zhengdong D. Zhang
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY USA
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27
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Chung FFL, Tan PFTM, Raja VJ, Tan BS, Lim KH, Kam TS, Hii LW, Tan SH, See SJ, Tan YF, Wong LZ, Yam WK, Mai CW, Bradshaw TD, Leong CO. Jerantinine A induces tumor-specific cell death through modulation of splicing factor 3b subunit 1 (SF3B1). Sci Rep 2017; 7:42504. [PMID: 28198434 PMCID: PMC5309811 DOI: 10.1038/srep42504] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 01/13/2017] [Indexed: 02/08/2023] Open
Abstract
Precursor mRNA (pre-mRNA) splicing is catalyzed by a large ribonucleoprotein complex known as the spliceosome. Numerous studies have indicated that aberrant splicing patterns or mutations in spliceosome components, including the splicing factor 3b subunit 1 (SF3B1), are associated with hallmark cancer phenotypes. This has led to the identification and development of small molecules with spliceosome-modulating activity as potential anticancer agents. Jerantinine A (JA) is a novel indole alkaloid which displays potent anti-proliferative activities against human cancer cell lines by inhibiting tubulin polymerization and inducing G2/M cell cycle arrest. Using a combined pooled-genome wide shRNA library screen and global proteomic profiling, we showed that JA targets the spliceosome by up-regulating SF3B1 and SF3B3 protein in breast cancer cells. Notably, JA induced significant tumor-specific cell death and a significant increase in unspliced pre-mRNAs. In contrast, depletion of endogenous SF3B1 abrogated the apoptotic effects, but not the G2/M cell cycle arrest induced by JA. Further analyses showed that JA stabilizes endogenous SF3B1 protein in breast cancer cells and induced dissociation of the protein from the nucleosome complex. Together, these results demonstrate that JA exerts its antitumor activity by targeting SF3B1 and SF3B3 in addition to its reported targeting of tubulin polymerization.
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Affiliation(s)
- Felicia Fei-Lei Chung
- Center for Cancer and Stem Cell Research, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
| | | | - Vijay Joseph Raja
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10021, USA
| | - Boon-Shing Tan
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Kuan-Hon Lim
- School of Pharmacy, University of Nottingham Malaysia Campus, Jalan Broga, 43500 Semenyih, Selangor, Malaysia
| | - Toh-Seok Kam
- Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Ling-Wei Hii
- Center for Cancer and Stem Cell Research, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
- School of Postgraduate Studies, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
| | - Si Hoey Tan
- Center for Cancer and Stem Cell Research, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
- School of Postgraduate Studies, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
| | - Sze-Jia See
- Center for Cancer and Stem Cell Research, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
| | - Yuen-Fen Tan
- Center for Cancer and Stem Cell Research, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
- School of Postgraduate Studies, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
| | - Li-Zhe Wong
- Center for Cancer and Stem Cell Research, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
- School of Postgraduate Studies, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
| | - Wai Keat Yam
- School of Pharmacy, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
| | - Chun Wai Mai
- School of Pharmacy, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
| | - Tracey D. Bradshaw
- School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Chee-Onn Leong
- Center for Cancer and Stem Cell Research, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
- School of Pharmacy, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
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28
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29
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Lu Z, Xiao Z, Liu F, Cui M, Li W, Yang Z, Li J, Ye L, Zhang X. Long non-coding RNA HULC promotes tumor angiogenesis in liver cancer by up-regulating sphingosine kinase 1 (SPHK1). Oncotarget 2016; 7:241-54. [PMID: 26540633 PMCID: PMC4807995 DOI: 10.18632/oncotarget.6280] [Citation(s) in RCA: 153] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 10/08/2015] [Indexed: 02/06/2023] Open
Abstract
Highly up-regulated in liver cancer (HULC) is a long non-coding RNA (lncRNA). We found that HULC up-regulated sphingosine kinase 1 (SPHK1), which is involved in tumor angiogenesis. Levels of HULC were positively correlated with levels of SPHK1 and its product, sphingosine-1-phosphate (S1P), in patients HCC samples. HULC increased SPHK1 in hepatoma cells. Chicken chorioallantoic membrane (CAM) assays revealed that si-SPHK1 remarkably blocked the HULC-enhanced angiogenesis. Mechanistically, HULC activated the promoter of SPHK1 in hepatoma cells through the transcription factor E2F1. Chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA) further showed that E2F1 was capable of binding to the E2F1 element in the SPHK1 promoter. HULC increased the expression of E2F1 in hepatoma cells and levels of HULC were positively correlated with those of E2F1 in HCC tissues. Intriguingly, HULC sequestered miR-107, which targeted E2F1 mRNA 3′UTR, by complementary base pairing. Functionally, si-SPHK1 remarkably abolished the HULC-enhanced tumor angiogenesis in vitro and in vivo. Taken together, we conclude that HULC promotes tumor angiogenesis in liver cancer through miR-107/E2F1/SPHK1 signaling. Our finding provides new insights into the mechanism of tumor angiogenesis.
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Affiliation(s)
- Zhanping Lu
- The State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin, P.R. China
| | - Zelin Xiao
- The State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin, P.R. China
| | - Fabao Liu
- The State Key Laboratory of Medicinal Chemical Biology, Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin, P.R. China
| | - Ming Cui
- The State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin, P.R. China
| | - Weiping Li
- The State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin, P.R. China.,Department of Medical Science Laboratory, Fenyang College, Shanxi Medical University, Fenyang, Shanxi Provence, P.R. China
| | - Zhe Yang
- The State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin, P.R. China
| | - Jiong Li
- The State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin, P.R. China
| | - Lihong Ye
- The State Key Laboratory of Medicinal Chemical Biology, Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin, P.R. China
| | - Xiaodong Zhang
- The State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin, P.R. China
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30
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Hsu PY, Hsi E, Wang TM, Lin RT, Liao YC, Juo SHH. MicroRNA let-7g possesses a therapeutic potential for peripheral artery disease. J Cell Mol Med 2016; 21:519-529. [PMID: 27696675 PMCID: PMC5323674 DOI: 10.1111/jcmm.12997] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 08/23/2016] [Indexed: 12/28/2022] Open
Abstract
Peripheral artery disease (PAD) is a manifestation of systemic atherosclerosis and conveys a significant health burden globally. Critical limb ischaemia encompasses the most severe consequence of PAD. Our previous studies indicate that microRNA let‐7g prevents atherosclerosis and improves endothelial functions. This study aimed to investigate whether and how let‐7g therapy may improve blood flow to ischaemic limbs. The present study shows that let‐7g has multiple pro‐angiogenic effects on mouse ischaemic limb model and could be a potential therapeutic agent for PAD. Mice receiving intramuscular injection of let‐7g had more neovascularization, better local perfusion and increased recruitment of endothelial progenitor cells after hindlimb ischaemia. The therapeutic effects of let‐7g's on angiogenesis are mediated by multiple regulatory machinery. First, let‐7g increased expression of vascular endothelial growth factor‐A (VEGF‐A) and VEGF receptor‐2 (VEGFR‐2) through targeting their upstream regulators HIF‐3α and TP53. In addition, let‐7g affected the splicing factor SC35 which subsequently enhanced the alternative splicing of VEGF‐A from the anti‐angiogenic isoform VEGF‐A165b towards the pro‐angiogenic isoform VEGF‐A164a. The pleiotropic effects of let‐7g on angiogenesis imply that let‐7g may possess a therapeutic potential in ischaemic diseases.
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Affiliation(s)
- Po-Yuan Hsu
- Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
| | - Edward Hsi
- Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
| | - Tzu-Ming Wang
- Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
| | - Ruey-Tay Lin
- Department of Neurology, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Chu Liao
- Department of Neurology, National Yang-Ming University School of Medicine, Taipei, Taiwan.,Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Suh-Hang H Juo
- Department of Medical Research, China Medical University Hospital, Taichung, Taiwan.,Department of Neurology, Kaohsiung Medical University, Kaohsiung, Taiwan.,Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
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31
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Ertosun MG, Hapil FZ, Osman Nidai O. E2F1 transcription factor and its impact on growth factor and cytokine signaling. Cytokine Growth Factor Rev 2016; 31:17-25. [PMID: 26947516 DOI: 10.1016/j.cytogfr.2016.02.001] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 02/27/2016] [Indexed: 12/13/2022]
Abstract
E2F1 is a transcription factor involved in cell cycle regulation and apoptosis. The transactivation capacity of E2F1 is regulated by pRb. In its hypophosphorylated form, pRb binds and inactivates DNA binding and transactivating functions of E2F1. The growth factor stimulation of cells leads to activation of CDKs (cyclin dependent kinases), which in turn phosphorylate Rb and hyperphosphorylated Rb is released from E2F1 or E2F1/DP complex, and free E2F1 can induce transcription of several genes involved in cell cycle entry, induction or inhibition of apoptosis. Thus, growth factors and cytokines generally utilize E2F1 to direct cells to either fate. Furthermore, E2F1 regulates expressions of various cytokines and growth factor receptors, establishing positive or negative feedback mechanisms. This review focuses on the relationship between E2F1 transcription factor and cytokines (IL-1, IL-2, IL-3, IL-6, TGF-beta, G-CSF, LIF), growth factors (EGF, KGF, VEGF, IGF, FGF, PDGF, HGF, NGF), and interferons (IFN-α, IFN-β and IFN-γ).
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Affiliation(s)
- Mustafa Gokhan Ertosun
- Akdeniz University, Faculty of Medicine, Department of Medical Biology and Genetic, Kampus, Antalya 07070, Turkey
| | - Fatma Zehra Hapil
- Akdeniz University, Faculty of Medicine, Department of Medical Biology and Genetic, Kampus, Antalya 07070, Turkey
| | - Ozes Osman Nidai
- Akdeniz University, Faculty of Medicine, Department of Medical Biology and Genetic, Kampus, Antalya 07070, Turkey.
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32
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Splicing Regulators and Their Roles in Cancer Biology and Therapy. BIOMED RESEARCH INTERNATIONAL 2015; 2015:150514. [PMID: 26273588 PMCID: PMC4529883 DOI: 10.1155/2015/150514] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 03/10/2015] [Accepted: 04/01/2015] [Indexed: 12/17/2022]
Abstract
Alternative splicing allows cells to expand the encoding potential of their genomes. In this elegant mechanism, a single gene can yield protein isoforms with even antagonistic functions depending on the cellular physiological context. Alterations in splicing regulatory factors activity in cancer cells, however, can generate an abnormal protein expression pattern that promotes growth, survival, and other processes, which are relevant to tumor biology. In this review, we discuss dysregulated alternative splicing events and regulatory factors that impact pathways related to cancer. The SR proteins and their regulatory kinases SRPKs and CLKs have been frequently found altered in tumors and are examined in more detail. Finally, perspectives that support splicing machinery as target for the development of novel anticancer therapies are discussed.
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33
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Shen W, Yin R, Wang C, Zhu M, Zhou W, Qin N, Sun J, Liu J, Dong J, Jin G, Ma H, Hu Z, Shen H, Xu L, Dai J. Polymorphisms in alternative splicing associated genes are associated with lung cancer risk in a Chinese population. Lung Cancer 2015; 89:238-42. [PMID: 26162562 DOI: 10.1016/j.lungcan.2015.06.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 05/19/2015] [Accepted: 06/14/2015] [Indexed: 11/26/2022]
Abstract
BACKGROUND Alternative splicing is an important biological step during mRNA processing. Misregulation of alternative splicing can produce aberrant protein isoforms, thus contributing to cancer. We hypothesized that variants in 5 critical splicing factor-associated genes might play an important role in carcinogenesis of lung cancer. MATERIALS AND METHODS A case-control study including 1,341 non-small cell lung cancer (NSCLC) cases and 1,982 cancer-free controls were conducted to evaluate the associations of 16 tagging/functional polymorphisms in 5 splicing factor-associated genes with lung cancer risk. RESULTS We found altogether 8 SNPs were associated with lung cancer risk with adjustment of age, gender, and smoking status after multiple corrections (FDR). Among these, six SNPs were related with SRSF7(rs10197412, OR (95% CI)=1.23 (1.06-1.43), P for FDR=0.018; rs12621103, OR(95% CI)=1.25 (1.08-1.46), P for FDR=0.016; rs13024811, OR (95% CI)=1.25 (1.07-1.46), P for FDR=0.016; rs2037875, OR (95% CI)=1.23 (1.06-1.42), P for FDR=0.018; rs3134628, OR (95% CI)=1.25(1.07-1.45), P for FDR=0.016 and rs6715866, OR (95% CI)=1.23 (1.07-1.43), P for FDR=0.016); one SNP was near PTBP2 (rs12566237: OR (95% CI)=1.16 (1.05-1.28), P for FDR=0.016) and one SNP in HNRNPQ (rs16876385: OR (95% CI)=1.17 (1.04-1.32), P for FDR=0.022). CONCLUSIONS Our findings indicated that genetic variants in these splicing-associated genes might modify individual susceptibility to lung cancer in Chinese population. Further large-scale well-formed population studies and functional researches are warranted to confirm our findings.
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Affiliation(s)
- Wei Shen
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Rong Yin
- Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University Affiliated Cancer Hospital, Nanjing 210009, China
| | - Cheng Wang
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Meng Zhu
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Wen Zhou
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Na Qin
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Jie Sun
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Jia Liu
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Jing Dong
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Guangfu Jin
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Hongxia Ma
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Zhibin Hu
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China; Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University Affiliated Cancer Hospital, Nanjing 210009, China
| | - Hongbing Shen
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Lin Xu
- Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Collaborative Innovation Center For Cancer Personalized Medicine, Nanjing Medical University Affiliated Cancer Hospital, Nanjing 210009, China.
| | - Juncheng Dai
- Department of Epidemiology and Biostatistics, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing 211166, China.
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Farrokh S, Brillen AL, Haendeler J, Altschmied J, Schaal H. Critical regulators of endothelial cell functions: for a change being alternative. Antioxid Redox Signal 2015; 22:1212-29. [PMID: 25203279 DOI: 10.1089/ars.2014.6023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
SIGNIFICANCE The endothelium regulates vessel dilation and constriction, balances hemostasis, and inhibits thrombosis. In addition, pro- and anti-angiogenic molecules orchestrate proliferation, survival, and migration of endothelial cells. Regulation of all these processes requires fine-tuning of signaling pathways, which can easily be tricked into running the opposite direction when exogenous or endogenous signals get out of hand. Surprisingly, some critical regulators of physiological endothelial functions can turn malicious by mere alternative splicing, leading to the expression of protein isoforms with opposite functions. RECENT ADVANCES While reviewing the evidence of alternative splicing on cellular physiology, it became evident that expression of splice factors and their activities are regulated by externally triggered signaling cascades. Furthermore, genome-wide identification of RNA-binding sites of splicing regulatory proteins now offer a glimpse into the splicing code responsible for alternative splicing of molecules regulating endothelial functions. CRITICAL ISSUES Due to the constantly growing number of transcript and protein isoforms, it will become more and more important to identify and characterize all transcripts and proteins regulating endothelial cell functions. One critical issue will be a non-ambiguous nomenclature to keep consistency throughout different laboratories. FUTURE DIRECTIONS RNA-deep sequencing focusing on exon-exon junction needs to more reliably identify alternative splicing events combined with functional analyses that will uncover more splice variants contributing to or inhibiting proper endothelial functions. In addition, understanding the signals mediating alternative splicing and its regulation might allow us to derive new strategies to preserve endothelial function by suppressing or upregulating specific protein isoforms. Antioxid. Redox Signal. 22, 1212-1229.
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Affiliation(s)
- Sabrina Farrokh
- 1 Heisenberg-Group-Environmentally-Induced Cardiovascular Degeneration, IUF-Leibniz Research Institute for Environmental Medicine , Düsseldorf, Germany
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Schaal C, Pillai S, Chellappan SP. The Rb-E2F transcriptional regulatory pathway in tumor angiogenesis and metastasis. Adv Cancer Res 2015; 121:147-182. [PMID: 24889531 DOI: 10.1016/b978-0-12-800249-0.00004-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The retinoblastoma tumor suppressor protein Rb plays a major role in regulating G1/S transition and is a critical regulator of cell proliferation. Rb protein exerts its growth regulatory properties mainly by physically interacting with the transcriptionally active members of the E2F transcription factor family, especially E2Fs 1, 2, and 3. Given its critical role in regulating cell proliferation, it is not surprising that Rb is inactivated in almost all tumors, either through the mutation of Rb gene itself or through the mutations of its upstream regulators including K-Ras and INK4. Recent studies have revealed a significant role for Rb and its downstream effectors, especially E2Fs, in regulating various aspects of tumor progression, angiogenesis, and metastasis. Thus, components of the Rb-E2F pathway have been shown to regulate the expression of genes involved in angiogenesis, including VEGF and VEGFR, genes involved in epithelial-mesenchymal transition including E-cadherin and ZEB proteins, and genes involved in invasion and migration like matrix metalloproteinases. Rb has also been shown to play a major role in the functioning of normal and cancer stem cells; further, Rb and E2F appear to play a regulatory role in the energy metabolism of cancer cells. These findings raise the possibility that mutational events that initiate tumorigenesis by inducing uncontrolled cell proliferation might also contribute to the progression and metastasis of cancers through the mediation of the Rb-E2F transcriptional regulatory pathway. This review highlights these recent studies on tumor promoting functions of the Rb-E2F pathway.
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Affiliation(s)
- Courtney Schaal
- Department of Tumor Biology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA
| | - Smitha Pillai
- Department of Tumor Biology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA
| | - Srikumar P Chellappan
- Department of Tumor Biology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA.
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Abstract
Vascular endothelial growth factor A (VEGF-A) is a potent proangiogenic cytokine elevated in patients with peripheral artery disease (PAD). A new study links impaired vascular regrowth in PAD to increased expression of an antiangiogenic splice variant of VEGF-A.
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37
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Maglic D, Stovall DB, Cline JM, Fry EA, Mallakin A, Taneja P, Caudell DL, Willingham MC, Sui G, Inoue K. DMP1β, a splice isoform of the tumour suppressor DMP1 locus, induces proliferation and progression of breast cancer. J Pathol 2015; 236:90-102. [PMID: 25537728 DOI: 10.1002/path.4504] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 12/13/2014] [Accepted: 12/21/2014] [Indexed: 01/20/2023]
Abstract
Our recent work has indicated that the DMP1 locus on 7q21, encoding a haplo-insufficient tumour suppressor, is hemizygously deleted at a high frequency in breast cancer. The locus encodes DMP1α protein, an activator of the p53 pathway leading to cell cycle arrest and senescence, and two other functionally undefined isoforms, DMP1β and DMP1γ. In this study, we show that the DMP1 locus is alternatively spliced in ∼30% of breast cancer cases with relatively decreased DMP1α and increased DMP1β expression. RNA-seq analyses of a publicly available database showed significantly increased DMP1β mRNA in 43-55% of human breast cancers, dependent on histological subtypes. Similarly, DMP1β protein was found to be overexpressed in ∼60% of tumours relative to their surrounding normal tissue. Importantly, alteration of DMP1 splicing and DMP1β overexpression were associated with poor clinical outcomes of the breast cancer patients, indicating that DMP1β may have a biological function. Indeed, DMP1β increased proliferation of non-tumourigenic mammary epithelial cells and knockdown of endogenous DMP1 inhibited breast cancer cell growth. To determine DMP1β's role in vivo, we established MMTV-DMP1β transgenic mouse lines. DMP1β overexpression was sufficient to induce mammary gland hyperplasia and multifocal tumour lesions in mice at 7-18 months of age. The tumours formed were adenosquamous carcinomas with evidence of transdifferentiation and keratinized deposits. Overall, we identify alternative splicing as a mechanism utilized by cancer cells to modulate the DMP1 locus through diminishing DMP1α tumour suppressor expression, while simultaneously up-regulating the tumour-promoting DMP1β isoform.
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Affiliation(s)
- Dejan Maglic
- Department of Cancer Biology, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA; Department of Pathology, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA; Graduate Program in Molecular Medicine, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA
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Shilo A, Siegfried Z, Karni R. The role of splicing factors in deregulation of alternative splicing during oncogenesis and tumor progression. Mol Cell Oncol 2015; 2:e970955. [PMID: 27308389 PMCID: PMC4905244 DOI: 10.4161/23723548.2014.970955] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 09/13/2014] [Accepted: 09/15/2014] [Indexed: 04/18/2023]
Abstract
In past decades, cancer research has focused on genetic alterations that are detected in malignant tissues and contribute to the initiation and progression of cancer. These changes include mutations, copy number variations, and translocations. However, it is becoming increasingly clear that epigenetic changes, including alternative splicing, play a major role in cancer development and progression. There are relatively few studies on the contribution of alternative splicing and the splicing factors that regulate this process to cancer development and progression. Recently, multiple studies have revealed altered splicing patterns in cancers and several splicing factors were found to contribute to tumor development. Studies using high-throughput genomic analysis have identified mutations in components of the core splicing machinery and in splicing factors in several cancers. In this review, we will highlight new findings on the role of alternative splicing and its regulators in cancer initiation and progression, in addition to novel approaches to correct oncogenic splicing.
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Affiliation(s)
- Asaf Shilo
- Department of Biochemistry and Molecular Biology; Institute for Medical Research Israel-Canada; Hebrew University-Hadassah Medical School; Ein Karem, Jerusalem, Israel
| | - Zahava Siegfried
- Department of Biochemistry and Molecular Biology; Institute for Medical Research Israel-Canada; Hebrew University-Hadassah Medical School; Ein Karem, Jerusalem, Israel
| | - Rotem Karni
- Department of Biochemistry and Molecular Biology; Institute for Medical Research Israel-Canada; Hebrew University-Hadassah Medical School; Ein Karem, Jerusalem, Israel
- Correspondence to: Rotem Karni;
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39
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Hamdollah Zadeh MA, Amin EM, Hoareau-Aveilla C, Domingo E, Symonds KE, Ye X, Heesom KJ, Salmon A, D'Silva O, Betteridge KB, Williams AC, Kerr DJ, Salmon AHJ, Oltean S, Midgley RS, Ladomery MR, Harper SJ, Varey AHR, Bates DO. Alternative splicing of TIA-1 in human colon cancer regulates VEGF isoform expression, angiogenesis, tumour growth and bevacizumab resistance. Mol Oncol 2015; 9:167-78. [PMID: 25224594 PMCID: PMC4286123 DOI: 10.1016/j.molonc.2014.07.017] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 07/23/2014] [Accepted: 07/24/2014] [Indexed: 02/06/2023] Open
Abstract
The angiogenic capability of colorectal carcinomas (CRC), and their susceptibility to anti-angiogenic therapy, is determined by expression of vascular endothelial growth factor (VEGF) isoforms. The intracellular protein T-cell Intracellular Antigen (TIA-1) alters post-transcriptional RNA processing and binds VEGF-A mRNA. We therefore tested the hypothesis that TIA-1 could regulate VEGF-A isoform expression in colorectal cancers. TIA-1 and VEGF-A isoform expression was measured in colorectal cancers and cell lines. We discovered that an endogenous splice variant of TIA-1 encoding a truncated protein, short TIA-1 (sTIA-1) was expressed in CRC tissues and invasive K-Ras mutant colon cancer cells and tissues but not in adenoma cell lines. sTIA-1 was more highly expressed in CRC than in normal tissues and increased with tumour stage. Knockdown of sTIA-1 or over-expression of full length TIA-1 (flTIA-1) induced expression of the anti-angiogenic VEGF isoform VEGF-A165b. Whereas flTIA-1 selectively bound VEGF-A165 mRNA and increased translation of VEGF-A165b, sTIA-1 prevented this binding. In nude mice, xenografted colon cancer cells over-expressing flTIA-1 formed smaller, less vascular tumours than those expressing sTIA-1, but flTIA-1 expression inhibited the effect of anti-VEGF antibodies. These results indicate that alternative splicing of an RNA binding protein can regulate isoform specific expression of VEGF providing an added layer of complexity to the angiogenic profile of colorectal cancer and their resistance to anti-angiogenic therapy.
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Affiliation(s)
- Maryam A Hamdollah Zadeh
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Elianna M Amin
- Centre for Research in Biomedicine, Faculty of Health and Life Sciences, University of the West of England, Bristol BS16 1QY, UK
| | - Coralie Hoareau-Aveilla
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Enric Domingo
- Molecular and Population Genetics, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Kirsty E Symonds
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Xi Ye
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Katherine J Heesom
- Proteomics Facility, Faculty of Veterinary and Medical Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Andrew Salmon
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Olivia D'Silva
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Kai B Betteridge
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Ann C Williams
- School of Cellular and Molecular Medicine, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - David J Kerr
- Nuffield Dept Clinical and Laboratory Sciences, University of Oxford, UK
| | - Andrew H J Salmon
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Sebastian Oltean
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Rachel S Midgley
- Molecular and Population Genetics, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Michael R Ladomery
- Centre for Research in Biomedicine, Faculty of Health and Life Sciences, University of the West of England, Bristol BS16 1QY, UK
| | - Steven J Harper
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Alexander H R Varey
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - David O Bates
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK; Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, NG7 2UH, UK.
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40
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An antiangiogenic isoform of VEGF-A contributes to impaired vascularization in peripheral artery disease. Nat Med 2014; 20:1464-71. [PMID: 25362254 PMCID: PMC4257756 DOI: 10.1038/nm.3703] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 08/28/2014] [Indexed: 11/17/2022]
Abstract
Peripheral artery disease (PAD) generates tissue ischemia through arterial occlusions and insufficient collateral vessel formation. Vascular insufficiency in PAD occurs despite higher circulating levels of vascular endothelial growth factor A (VEGF-A),1,2 a key regulator of angiogenesis. Here, we show that clinical PAD is associated with elevated anti-angiogenic VEGF-A splice isoform (VEGF-A165b), and a corresponding reduction of the pro-angiogenic VEGF-A165a isoform. In a murine model of PAD, VEGF-A165b was upregulated by conditions associated with impaired limb revascularization, including leptin-deficiency, diet-induced obesity, genetic ablation of the secreted frizzled-related protein 5 (Sfrp5) adipokine and transgenic overexpression of Wnt5a in myeloid cells. In PAD models, delivery of VEGF-A165b inhibited revascularization of ischemic hind limbs, whereas treatment with an isoform-specific neutralizing antibody reversed the impaired revascularization phenotype caused by metabolic dysfunction or perturbations in the Wnt5a/Sfrp5 regulatory system. These results indicate that inflammation driven expression of the anti-angiogenic VEGF-A isoform can contribute to impaired collateralization in ischemic cardiovascular disease.
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Wu M, Zhou J, Cheng M, Boriboun C, Biyashev D, Wang H, Mackie A, Thorne T, Chou J, Wu Y, Chen Z, Liu Q, Yan H, Yang Y, Jie C, Tang YL, Zhao TC, Taylor RN, Kishore R, Losordo DW, Qin G. E2F1 suppresses cardiac neovascularization by down-regulating VEGF and PlGF expression. Cardiovasc Res 2014; 104:412-22. [PMID: 25341896 DOI: 10.1093/cvr/cvu222] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
AIMS The E2F transcription factors are best characterized for their roles in cell-cycle regulation, cell growth, and cell death. Here we investigated the potential role of E2F1 in cardiac neovascularization. METHODS AND RESULTS We induced myocardial infarction (MI) by ligating the left anterior descending artery in wild-type (WT) and E2F1(-/-) mice. E2F1(-/-) mice demonstrated a significantly better cardiac function and smaller infarct sizes than WT mice. At infarct border zone, capillary density and endothelial cell (EC) proliferation were greater, apoptotic ECs were fewer, levels of VEGF and placental growth factor (PlGF) were higher, and p53 level was lower in E2F1(-/-) than in WT mice. Blockade of VEGF receptor 2 (VEGFR2) signalling with the selective inhibitor SU5416 or with the VEGFR2-blocking antibody DC101 abolished the differences between E2F1(-/-) mice and WT mice in cardiac function, infarct size, capillary density, EC proliferation, and EC apoptosis. In vitro, hypoxia-induced VEGF and PlGF up-regulation was significantly greater in E2F1(-/-) than in WT cardiac fibroblasts, and E2F1 overexpression suppressed PlGF up-regulation in both WT and p53(-/-) cells; however, VEGF up-regulation was suppressed only in WT cells. E2F1 interacted with and stabilized p53 under hypoxic conditions, and both E2F1 : p53 binding and the E2F1-induced suppression of VEGF promoter activity were absent in cells that expressed an N-terminally truncated E2F1 mutant. CONCLUSION E2F1 limits cardiac neovascularization and functional recovery after MI by suppressing VEGF and PlGF up-regulation through p53-dependent and -independent mechanisms, respectively.
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Affiliation(s)
- Min Wu
- Department of Plastic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Medicine-Cardiology, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave., Tarry 14-721, Chicago, IL 60611, USA
| | - Junlan Zhou
- Department of Medicine-Cardiology, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave., Tarry 14-721, Chicago, IL 60611, USA
| | - Min Cheng
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Chan Boriboun
- Department of Medicine-Cardiology, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave., Tarry 14-721, Chicago, IL 60611, USA
| | - Dauren Biyashev
- Department of Medicine-Cardiology, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave., Tarry 14-721, Chicago, IL 60611, USA
| | - Hong Wang
- Department of Medicine-Cardiology, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave., Tarry 14-721, Chicago, IL 60611, USA
| | - Alexander Mackie
- Department of Medicine-Cardiology, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave., Tarry 14-721, Chicago, IL 60611, USA
| | - Tina Thorne
- Department of Medicine-Cardiology, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave., Tarry 14-721, Chicago, IL 60611, USA
| | - Jonathan Chou
- Department of Medicine-Cardiology, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave., Tarry 14-721, Chicago, IL 60611, USA
| | - Yiping Wu
- Department of Plastic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Zhishui Chen
- Organ Transplantation Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Qinghua Liu
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China
| | - Hongbin Yan
- Cardiology Department, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ya Yang
- Department of Echocardiography, Beijing Anzhen Hospital, Capital Medical University and Beijing Institute of Heart, Lung and Blood Vessel Disease, Beijing, China
| | - Chunfa Jie
- Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Yao-Liang Tang
- Department of Medicine, Vascular Biology Center, Medical College of Georgia/Georgia Regents University, Augusta, GA, USA
| | - Ting C Zhao
- Department of Surgery, Roger Williams Medical Center, Boston University Medical School, Boston University, Providence, RI, USA
| | - Robert N Taylor
- Department of Obstetrics and Gynecology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Raj Kishore
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA, USA
| | - Douglas W Losordo
- Department of Medicine-Cardiology, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave., Tarry 14-721, Chicago, IL 60611, USA
| | - Gangjian Qin
- Department of Medicine-Cardiology, Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave., Tarry 14-721, Chicago, IL 60611, USA
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Lin JC, Lin CY, Tarn WY, Li FY. Elevated SRPK1 lessens apoptosis in breast cancer cells through RBM4-regulated splicing events. RNA (NEW YORK, N.Y.) 2014; 20:1621-31. [PMID: 25140042 PMCID: PMC4174443 DOI: 10.1261/rna.045583.114] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Imbalanced splicing of premessenger RNA is typical of tumorous malignancies, and the regulatory mechanisms involved in several tumorigenesis-associated splicing events are identified. Elevated expression of serine-arginine protein kinase 1 (SRPK1) may participate in the pathway responsible for the dysregulation of splicing events in malignant tumor cells. In this study, we observed a correlation between the cytoplasmic accumulation of RNA-binding motif protein 4 (RBM4) and up-regulated SRPK1 in breast cancer cells. The production of the IR-B and MCL-1S transcripts was induced separately by the overexpression of RBM4 and SRPK1 gene silencing. Overexpressed RBM4 simultaneously bound to the CU-rich elements within the MCL-1 exon2 and the downstream intron, which subsequently facilitated the exclusion of the regulated exon. Breast cancer cells are deprived of apoptotic resistance through the RBM4-mediated up-regulation of the IR-B and MCL-1S transcripts. These findings suggest that the splicing events regulated by the SRPK1-RMB4 network may contribute to tumorigenesis through altered sensitivity to apoptotic signals in breast cancer cells.
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MESH Headings
- Apoptosis
- Blotting, Western
- Breast/metabolism
- Breast Neoplasms/genetics
- Breast Neoplasms/metabolism
- Breast Neoplasms/pathology
- Carcinoma, Ductal, Breast/genetics
- Carcinoma, Ductal, Breast/metabolism
- Carcinoma, Ductal, Breast/pathology
- Cell Proliferation
- Cells, Cultured
- Electrophoretic Mobility Shift Assay
- Female
- Gene Expression Regulation, Neoplastic
- Humans
- Immunoenzyme Techniques
- Myeloid Cell Leukemia Sequence 1 Protein/genetics
- Neoplasm Grading
- Neoplasm Invasiveness
- Neoplasm Staging
- Phosphorylation
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- RNA Splicing/genetics
- RNA, Messenger/genetics
- RNA, Small Interfering/genetics
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Transcriptional Activation
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Affiliation(s)
- Jung-Chun Lin
- School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, 110, Taipei, Taiwan
| | - Ching-Yu Lin
- School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, 110, Taipei, Taiwan
| | - Woan-Yuh Tarn
- Institute of Biomedical Sciences, Academia Sinica, 115, Taipei, Taiwan
| | - Fang-Yu Li
- School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, 110, Taipei, Taiwan
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The E2F transcription factors regulate tumor development and metastasis in a mouse model of metastatic breast cancer. Mol Cell Biol 2014; 34:3229-43. [PMID: 24934442 DOI: 10.1128/mcb.00737-14] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
While the E2F transcription factors (E2Fs) have a clearly defined role in cell cycle control, recent work has uncovered new functions. Using genomic signature methods, we predicted a role for the activator E2F transcription factors in the mouse mammary tumor virus (MMTV)-polyomavirus middle T oncoprotein (PyMT) mouse model of metastatic breast cancer. To genetically test the hypothesis that the E2Fs function to regulate tumor development and metastasis, we interbred MMTV-PyMT mice with E2F1, E2F2, or E2F3 knockout mice. With the ablation of individual E2Fs, we noted alterations of tumor latency, histology, and vasculature. Interestingly, we noted striking reductions in metastatic capacity and in the number of circulating tumor cells in both the E2F1 and E2F2 knockout backgrounds. Investigating E2F target genes that mediate metastasis, we found that E2F loss led to decreased levels of vascular endothelial growth factor (Vegfa), Bmp4, Cyr61, Nupr1, Plod 2, P4ha1, Adamts1, Lgals3, and Angpt2. These gene expression changes indicate that the E2Fs control the expression of genes critical to angiogenesis, the remodeling of the extracellular matrix, tumor cell survival, and tumor cell interactions with vascular endothelial cells that facilitate metastasis to the lungs. Taken together, these results reveal that the E2F transcription factors play key roles in mediating tumor development and metastasis in addition to their well-characterized roles in cell cycle control.
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Al-Ansari MM, Aboussekhra A. Caffeine mediates sustained inactivation of breast cancer-associated myofibroblasts via up-regulation of tumor suppressor genes. PLoS One 2014; 9:e90907. [PMID: 24595168 PMCID: PMC3940951 DOI: 10.1371/journal.pone.0090907] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 02/06/2014] [Indexed: 12/13/2022] Open
Abstract
Background Active cancer-associated fibroblasts (CAFs) or myofibroblasts play important roles not only in the development and progression of breast carcinomas, but also in their prognosis and treatment. Therefore, targeting these cells through suppressing their supportive procarcinogenic paracrine effects is mandatory for improving the current therapies that are mainly targeting tumor cells. To this end, we investigated the effect of the natural and pharmacologically safe molecule, caffeine, on CAF cells and their various procarcinogenic effects. Methodology/Principal Findings We have shown here that caffeine up-regulates the tumor suppressor proteins p16, p21, p53 and Cav-1, and reduces the expression/secretion of various cytokines (IL-6, TGF-β, SDF-1 and MMP-2), and down-regulates α-SMA. Furthermore, caffeine suppressed the migratory/invasiveness abilities of CAF cells through PTEN-dependent Akt/Erk1/2 inactivation. Moreover, caffeine reduced the paracrine pro-invasion/−migration effects of CAF cells on breast cancer cells. These results indicate that caffeine can inactivate breast stromal myofibroblasts. This has been confirmed by showing that caffeine also suppresses the paracrine pro-angiogenic effect of CAF cells through down-regulating HIF-1αand its downstream effector VEGF-A. Interestingly, these effects were sustained in absence of caffeine. Conclusion/Significance The present findings provide a proof of principle that breast cancer myofibroblasts can be inactivated, and thereby caffeine may provide a safe and effective prevention against breast tumor growth/recurrence through inhibition of the procarcinogenic effects of active stromal fibroblasts.
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Affiliation(s)
- Mysoon M. Al-Ansari
- Department of Microbiology, Faculty of Science and Medical Studies, King Saud University, Riyadh, Saudi Arabia
| | - Abdelilah Aboussekhra
- Department of Molecular Oncology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- * E-mail:
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Zhao YJ, Liang Y, Shi CZ, Han HZ, Zhu QC, Yang J. Clinical significance of differential expression of VEGF 165b between colorectal cancer and normal intestinal mucosa tissues. Shijie Huaren Xiaohua Zazhi 2014; 22:273-278. [DOI: 10.11569/wcjd.v22.i2.273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the differential expression of vascular endothelial growth factor (VEGF) 165b between colorectal cancer (CRC) and normal intestinal mucosa tissues and its role in the development of CRC.
METHODS: Real-time qRT-PCR was performed to detect the expression of VEGF 165b mRNA in 20 fresh CRC tissues and 20 matched normal intestinal mucosa tissues. Statistical methods were used to compare the expression of VEGF 165b in CRC tissues and normal intestinal mucosa tissues; tissues inside and outside the serosal layer; tissues with and without lymph node metastasis; tissues of TNM stages Ⅱ and Ⅲ tumors.
RESULTS: The positive expression rate of VEGF l65b mRNA in normal intestinal mucosa tissues was significantly higher than that in CRC tissues (P = 0.006). The expression of VEGF 165b was not statistically significant between CRC tissues and normal intestinal mucosa tissues, between tissues inside and outside the serosal layer, between tissues with and without lymph node metastasis, or tissues between TNM stages Ⅱ and Ⅲ tumors.
CONCLUSION: VEGF 165b might play a role in inhibiting the development of CRC and provide a new target for the diagnosis, prognosis and treatment of this malignancy.
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Pesson M, Eymin B, De La Grange P, Simon B, Corcos L. A dedicated microarray for in-depth analysis of pre-mRNA splicing events: application to the study of genes involved in the response to targeted anticancer therapies. Mol Cancer 2014; 13:9. [PMID: 24428911 PMCID: PMC3899606 DOI: 10.1186/1476-4598-13-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 01/09/2014] [Indexed: 12/22/2022] Open
Abstract
Alternative pre-mRNA splicing (AS) widely expands proteome diversity through the combinatorial assembly of exons. The analysis of AS on a large scale, by using splice-sensitive microarrays, is a highly efficient method to detect the majority of known and predicted alternative transcripts for a given gene. The response to targeted anticancer therapies cannot easily be anticipated without prior knowledge of the expression, by the tumor, of target proteins or genes. To analyze, in depth, transcript structure and levels for genes involved in these responses, including AKT1-3, HER1-4, HIF1A, PIK3CA, PIK3R1-2, VEGFA-D and PIR, we engineered a dedicated gene chip with coverage of an average 185 probes per gene and, especially, exon-exon junction probes. As a proof of concept, we demonstrated the ability of such a chip to detect the effects of over-expressed SRSF2 RNA binding protein on the structure and abundance of mRNA products in H358 lung cancer cells conditionally over-expressing SRSF2. Major splicing changes were observed, including in HER1/EGFR pre-mRNA, which were also seen in human lung cancer samples over-expressing the SRSF2 protein. In addition, we showed that variations in HER1/EGFR pre-mRNA splicing triggered by SRSF2 overexpression in H358 cells resulted in a drop in HER1/EGFR protein level, which correlated with increased sensitivity to gefitinib, an EGFR tyrosine kinase inhibitor. We propose, therefore, that this novel tool could be especially relevant for clinical applications, with the aim to predict the response before treatment.
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Affiliation(s)
| | | | | | | | - Laurent Corcos
- UMR INSERM U1078-UBO, Equipe ECLA, Faculté de Médecine, 22 Avenue Camille Desmoulins, 29200 Brest, France.
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Oltean S, Bates DO. Hallmarks of alternative splicing in cancer. Oncogene 2013; 33:5311-8. [PMID: 24336324 DOI: 10.1038/onc.2013.533] [Citation(s) in RCA: 451] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Revised: 11/04/2013] [Accepted: 11/04/2013] [Indexed: 12/17/2022]
Abstract
The immense majority of genes are alternatively spliced and there are many isoforms specifically associated with cancer progression and metastasis. The splicing pattern of specific isoforms of numerous genes is altered as cells move through the oncogenic process of gaining proliferative capacity, acquiring angiogenic, invasive, antiapoptotic and survival properties, becoming free from growth factor dependence and growth suppression, altering their metabolism to cope with hypoxia, enabling them to acquire mechanisms of immune escape, and as they move through the epithelial-mesenchymal and mesenchymal-epithelial transitions and metastasis. Each of the 'hallmarks of cancer' is associated with a switch in splicing, towards a more aggressive invasive cancer phenotype. The choice of isoforms is regulated by several factors (signaling molecules, kinases, splicing factors) currently being identified systematically by a number of high-throughput, independent and unbiased methodologies. Splicing factors are de-regulated in cancer, and in some cases are themselves oncogenes or pseudo-oncogenes and can contribute to positive feedback loops driving cancer progression. Tumour progression may therefore be associated with a coordinated splicing control, meaning that there is the potential for a relatively small number of splice factors or their regulators to drive multiple oncogenic processes. The understanding of how splicing contributes to the various phenotypic traits acquired by tumours as they progress and metastasise, and in particular how alternative splicing is coordinated, can and is leading to the development of a new class of anticancer therapeutics-the alternative-splicing inhibitors.
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Affiliation(s)
- S Oltean
- School of Physiology and Pharmacology, University of Bristol, Bristol, UK
| | - D O Bates
- Division of Pre-clinical Oncology, School of Clinical Sciences, University of Nottingham, Queen's Medical Center, Nottingham, UK
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Engelmann D, Mayoli-Nüssle D, Mayrhofer C, Fürst K, Alla V, Stoll A, Spitschak A, Abshagen K, Vollmar B, Ran S, Pützer BM. E2F1 promotes angiogenesis through the VEGF-C/VEGFR-3 axis in a feedback loop for cooperative induction of PDGF-B. J Mol Cell Biol 2013; 5:391-403. [PMID: 24014887 DOI: 10.1093/jmcb/mjt035] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Angiogenesis is essential for primary tumor growth and metastatic dissemination. E2F1, frequently upregulated in advanced cancers, was recently shown to drive malignant progression. In an attempt to decipher the molecular events underlying this behavior, we demonstrate that the tumor cell-associated vascular endothelial growth factor-C/receptor-3 (VEGF-C/VEGFR-3) axis is controlled by E2F1. Activation or forced expression of E2F1 in cancer cells leads to the upregulation of VEGFR-3 and its ligand VEGF-C, whereas E2F1 depletion prevents their expression. E2F1-dependent receptor induction is crucial for tumor cells to enhance formation of capillary tubes and neovascularization in mice. We further provide evidence for a positive feedback loop between E2F1 and VEGFR-3 signaling to stimulate pro-angiogenic platelet-derived growth factor B (PDGF-B). E2F1 or VEGFR-3 knockdown results in reduced PDGF-B levels, while the coexpression synergistically upregulates promoter activity and endogenous protein expression of PDGF-B. Our findings delineate an as yet unrecognized function of E2F1 as enhancer of angiogenesis via regulation of VEGF-C/VEGFR-3 signaling in tumors to cooperatively activate PDGF-B expression. Targeting this pathway might be reasonable to complement standard anti-angiogenic treatment of cancers with deregulated E2F1.
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Affiliation(s)
- David Engelmann
- Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, 18057 Rostock, Germany
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Juárez-Méndez S, Zentella-Dehesa A, Villegas-Ruíz V, Pérez-González OA, Salcedo M, López-Romero R, Román-Basaure E, Lazos-Ochoa M, Montes de Oca-Fuentes VE, Vázquez-Ortiz G, Moreno J. Splice variants of zinc finger protein 695 mRNA associated to ovarian cancer. J Ovarian Res 2013; 6:61. [PMID: 24007497 PMCID: PMC3847372 DOI: 10.1186/1757-2215-6-61] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 08/24/2013] [Indexed: 12/22/2022] Open
Abstract
Background Studies of alternative mRNA splicing (AS) in health and disease have yet to yield the complete picture of protein diversity and its role in physiology and pathology. Some forms of cancer appear to be associated to certain alternative mRNA splice variants, but their role in the cancer development and outcome is unclear. Methods We examined AS profiles by means of whole genome exon expression microarrays (Affymetrix GeneChip 1.0) in ovarian tumors and ovarian cancer-derived cell lines, compared to healthy ovarian tissue. Alternatively spliced genes expressed predominantly in ovarian tumors and cell lines were confirmed by RT-PCR. Results Among several significantly overexpressed AS genes in malignant ovarian tumors and ovarian cancer cell lines, the most significant one was that of the zinc finger protein ZNF695, with two previously unknown mRNA splice variants identified in ovarian tumors and cell lines. The identity of ZNF695 AS variants was confirmed by cloning and sequencing of the amplicons obtained from ovarian cancer tissue and cell lines. Conclusions Alternative ZNF695 mRNA splicing could be a marker of ovarian cancer with possible implications on its pathogenesis.
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50
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Arcondéguy T, Lacazette E, Millevoi S, Prats H, Touriol C. VEGF-A mRNA processing, stability and translation: a paradigm for intricate regulation of gene expression at the post-transcriptional level. Nucleic Acids Res 2013; 41:7997-8010. [PMID: 23851566 PMCID: PMC3783158 DOI: 10.1093/nar/gkt539] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Vascular Endothelial Growth Factor A (VEGF-A) is a potent secreted mitogen crucial for physiological and pathological angiogenesis. Post-transcriptional regulation of VEGF-A occurs at multiple levels. Firstly, alternative splicing gives rise to different transcript variants encoding diverse isoforms that exhibit distinct biological properties with regard to receptor binding and extra-cellular localization. Secondly, VEGF-A mRNA stability is regulated by effectors such as hypoxia or growth factors through the binding of stabilizing and destabilizing proteins at AU-rich elements located in the 3′-untranslated region. Thirdly, translation of VEGF-A mRNA is a controlled process involving alternative initiation codons, internal ribosome entry sites (IRESs), an upstream open reading frame (uORF), miRNA targeting and a riboswitch in the 3′ untranslated region. These different levels of regulation cooperate for the crucial fine-tuning of the expression of VEGF-A variants. This review will be focused on our current knowledge of the complex post-transcriptional regulatory switches that modulate the cellular VEGF-A level, a paradigmatic model of post-transcriptional regulation.
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Affiliation(s)
- Tania Arcondéguy
- Inserm UMR1037, Centre de Recherches en Cancérologie de Toulouse, CHU Rangueil, BP84225, 31432 Toulouse Cedex 4, France and Université Toulouse III Paul-Sabatier, 118 Route de Narbonne, 31400 Toulouse, France
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