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Zhang F, Sun J, Zhang L, Li R, Wang Y, Geng H, Shen C, Li L, Chen L. PARP inhibition leads to synthetic lethality with key splicing-factor mutations in myelodysplastic syndromes. Br J Cancer 2024:10.1038/s41416-024-02729-0. [PMID: 38806724 DOI: 10.1038/s41416-024-02729-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 05/14/2024] [Accepted: 05/17/2024] [Indexed: 05/30/2024] Open
Abstract
BACKGROUND Splicing factors are frequently mutated in patients with myelodysplastic syndromes and acute myeloid leukaemia. Recent studies have revealed convergent molecular defects caused by splicing factor mutations, among which R-loop dysregulation and resultant genome instability are suggested as contributing factors to disease progression. On the other hand, understanding how mutant cells survive upon aberrant R-loop formation and genome instability is essential for developing novel therapeutics. METHODS The immunoprecipitation was performed to identify R-loops in association with PARP1/poly-ADP-ribosylation. The western blot, immunofluorescence, and flow cytometry assays were used to test the cell viability, cell cycle arrest, apoptosis, and ATM activation in mutant cells following the treatment of the PARP inhibitor. The Srsf2(P95H) knock-in murine hematopoietic cells and MLL-AF9 transformed leukaemia model were generated to investigate the potential of the PARP inhibitor as a therapy for haematological malignancies. RESULTS The disease-causing mutations in SRSF2 activate PARP and elevate the overall poly-ADP-ribosylation levels of proteins in response to R-loop dysregulation. In accordance, mutant cells are more vulnerable to the PARP inhibitors in comparison to the wild-type counterpart. Notably, the synthetic lethality was further validated in the Srsf2(P95H) knock-in murine hematopoietic cell and MLL-AF9 leukaemia model. CONCLUSIONS Our findings suggest that mutant cells antagonise the genome threat caused by R-loop disruption by PARP activation, thus making PARP targeting a promising therapeutic strategy for myeloid cancers with mutations in SRSF2.
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Affiliation(s)
- Fangliang Zhang
- RNA Institute, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Jianai Sun
- Department of Hematological Malignancies Translational Science, Gehr Family Center for Leukemia Research, Hematologic Malignancies and Stem Cell Transplantation Institute, Beckman Research Institute, City of Hope Medical Center, Duarte, CA, USA
- Department of Hematology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Lei Zhang
- Department of Hematological Malignancies Translational Science, Gehr Family Center for Leukemia Research, Hematologic Malignancies and Stem Cell Transplantation Institute, Beckman Research Institute, City of Hope Medical Center, Duarte, CA, USA
| | - Ruiqi Li
- RNA Institute, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Yanzhen Wang
- RNA Institute, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Huichao Geng
- RNA Institute, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Chao Shen
- RNA Institute, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Ling Li
- Department of Hematological Malignancies Translational Science, Gehr Family Center for Leukemia Research, Hematologic Malignancies and Stem Cell Transplantation Institute, Beckman Research Institute, City of Hope Medical Center, Duarte, CA, USA.
| | - Liang Chen
- RNA Institute, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China.
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Tatwavedi D, Pellagatti A, Boultwood J. Recent advances in the application of induced pluripotent stem cell technology to the study of myeloid malignancies. Adv Biol Regul 2024; 91:100993. [PMID: 37827894 DOI: 10.1016/j.jbior.2023.100993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 09/25/2023] [Indexed: 10/14/2023]
Abstract
Acquired myeloid malignancies are a spectrum of clonal disorders known to be caused by sequential acquisition of genetic lesions in hematopoietic stem and progenitor cells, leading to their aberrant self-renewal and differentiation. The increasing use of induced pluripotent stem cell (iPSC) technology to study myeloid malignancies has helped usher a paradigm shift in approaches to disease modeling and drug discovery, especially when combined with gene-editing technology. The process of reprogramming allows for the capture of the diversity of genetic lesions and mutational burden found in primary patient samples into individual stable iPSC lines. Patient-derived iPSC lines, owing to their self-renewal and differentiation capacity, can thus be a homogenous source of disease relevant material that allow for the study of disease pathogenesis using various functional read-outs. Furthermore, genome editing technologies like CRISPR/Cas9 enable the study of the stepwise progression from normal to malignant hematopoiesis through the introduction of specific driver mutations, individually or in combination, to create isogenic lines for comparison. In this review, we survey the current use of iPSCs to model acquired myeloid malignancies including myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), acute myeloid leukemia and MDS/MPN overlap syndromes. The use of iPSCs has enabled the interrogation of the underlying mechanism of initiation and progression driving these diseases. It has also made drug testing, repurposing, and the discovery of novel therapies for these diseases possible in a high throughput setting.
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Affiliation(s)
- Dharamveer Tatwavedi
- Blood Cancer UK Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
| | - Andrea Pellagatti
- Blood Cancer UK Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Jacqueline Boultwood
- Blood Cancer UK Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
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3
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Pellagatti A, Boultwood J. Splicing factor mutations in the myelodysplastic syndromes: Role of key aberrantly spliced genes in disease pathophysiology and treatment. Adv Biol Regul 2023; 87:100920. [PMID: 36216757 DOI: 10.1016/j.jbior.2022.100920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 09/28/2022] [Accepted: 09/30/2022] [Indexed: 03/01/2023]
Abstract
Mutations of splicing factor genes (including SF3B1, SRSF2, U2AF1 and ZRSR2) occur in more than half of all patients with myelodysplastic syndromes (MDS), a heterogeneous group of myeloid neoplasms. Splicing factor mutations lead to aberrant pre-mRNA splicing of many genes, some of which have been shown in functional studies to impact on hematopoiesis and to contribute to the MDS phenotype. This clearly demonstrates that impaired spliceosome function plays an important role in MDS pathophysiology. Recent studies that harnessed the power of induced pluripotent stem cell (iPSC) and CRISPR/Cas9 gene editing technologies to generate new iPSC-based models of splicing factor mutant MDS, have further illuminated the role of key downstream target genes. The aberrantly spliced genes and the dysregulated pathways associated with splicing factor mutations in MDS represent potential new therapeutic targets. Emerging data has shown that IRAK4 is aberrantly spliced in SF3B1 and U2AF1 mutant MDS, leading to hyperactivation of NF-κB signaling. Pharmacological inhibition of IRAK4 has shown efficacy in pre-clinical studies and in MDS clinical trials, with higher response rates in patients with splicing factor mutations. Our increasing knowledge of the effects of splicing factor mutations in MDS is leading to the development of new treatments that may benefit patients harboring these mutations.
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Affiliation(s)
- Andrea Pellagatti
- Blood Cancer UK Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.
| | - Jacqueline Boultwood
- Blood Cancer UK Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.
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4
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De Kesel J, Fijalkowski I, Taylor J, Ntziachristos P. Splicing dysregulation in human hematologic malignancies: beyond splicing mutations. Trends Immunol 2022; 43:674-686. [PMID: 35850914 DOI: 10.1016/j.it.2022.06.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 06/09/2022] [Accepted: 06/14/2022] [Indexed: 11/16/2022]
Abstract
Splicing is a fundamental process in pre-mRNA maturation. Whereas alternative splicing (AS) enriches the diversity of the proteome, its aberrant regulation can drive oncogenesis. So far, most attention has been given to spliceosome mutations (SMs) in the context of splicing dysregulation in hematologic diseases. However, in recent years, post-translational modifications (PTMs) and transcriptional alterations of splicing factors (SFs), just as epigenetic signatures, have all been shown to contribute to global splicing dysregulation as well. In addition, the contribution of aberrant splicing to the neoantigen repertoire of cancers has been recognized. With the pressing need for novel therapeutics to combat blood cancers, this article provides an overview of emerging mechanisms that contribute to aberrant splicing, as well as their clinical potential.
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Affiliation(s)
- Jonas De Kesel
- Department of Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium; Cancer Research Institute Ghent, Ghent, Belgium; Center for Medical Genetics Ghent, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Igor Fijalkowski
- Department of Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium; Cancer Research Institute Ghent, Ghent, Belgium; Center for Medical Genetics Ghent, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Justin Taylor
- Division of Hematology, Department of Medicine, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Panagiotis Ntziachristos
- Department of Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium; Cancer Research Institute Ghent, Ghent, Belgium; Center for Medical Genetics Ghent, Ghent University and Ghent University Hospital, Ghent, Belgium.
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Comprehensive Analysis of N6-Methyladenosine Regulatory Genes from Citrus grandis and Expression Profilings in the Fruits of “Huajuhong” (C. grandis “Tomentosa”) during Various Development Stages. HORTICULTURAE 2022. [DOI: 10.3390/horticulturae8050462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Citrus grandis “Tomentosa” (“Huajuhong”) is a famous traditional Chinese medicine. The aim of the present study is to provide a comprehensive characterization of the m6A regulatory genes from C. grandis, and examine their expression patterns in fruits of C. grandis “Tomentosa” during various developmental stages. A total of 26 N6-methyladenosine (m6A) regulatory proteins were identified from the genome of C. grandis, which were distributed across nine chromosomes in C. grandis. Phylogenetic relationships revealed that all m6A regulatory genes were divided into groups of m6A writers, erasers, and readers. The m6A writer groups included CgMTA, CgMTB, and CgMTC three MTs (methyltransferases), one CgVIR (virilizer), one CgHAKAI (E3 ubiquitin ligase HAKAI), and one CgFIP37 (FKBP interacting protein 37). Moreover, 10 CgALKBH (α-ketoglutarate-dependent dioxygenase homolog) members (numbered from CgALKBH1 to CgALKBH10) and 10 CgECT (C-terminal region) members (numbered from CgECT1 to CgECT10) in C. grandis were identified as m6A erasers and readers, respectively. The domain structures and motif architectures among the groups of m6A writers, erasers, and readers were diverse. Cis-acting elements in the promoters of the 26 m6A regulatory genes predicted that the abscisic acid-responsive (ABA) element (ABRE) was present on the promoters of 19 genes. In addition, the expression profiles of all m6A regulatory genes were examined in the fruits of two varieties of C. grandis “Tomentosa” during different growth stages to give basic hints for further investigation of the function of the N6-methyladenosine regulatory genes in C. grandis “Tomentosa”.
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Lai HC, Ho UY, James A, De Souza P, Roberts TL. RNA metabolism and links to inflammatory regulation and disease. Cell Mol Life Sci 2021; 79:21. [PMID: 34971439 PMCID: PMC11072290 DOI: 10.1007/s00018-021-04073-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 09/29/2021] [Accepted: 10/22/2021] [Indexed: 11/29/2022]
Abstract
Inflammation is vital to protect the host against foreign organism invasion and cellular damage. It requires tight and concise gene expression for regulation of pro- and anti-inflammatory gene expression in immune cells. Dysregulated immune responses caused by gene mutations and errors in post-transcriptional regulation can lead to chronic inflammatory diseases and cancer. The mechanisms underlying post-transcriptional gene expression regulation include mRNA splicing, mRNA export, mRNA localisation, mRNA stability, RNA/protein interaction, and post-translational events such as protein stability and modification. The majority of studies to date have focused on transcriptional control pathways. However, post-transcriptional regulation of mRNA in eukaryotes is equally important and related information is lacking. In this review, we will focus on the mechanisms involved in the pre-mRNA splicing events, mRNA surveillance, RNA degradation pathways, disorders or symptoms caused by mutations or errors in post-transcriptional regulation during innate immunity especially toll-like receptor mediated pathways.
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Affiliation(s)
- Hui-Chi Lai
- Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia.
- South West Sydney Clinical School, UNSW Australia, Liverpool, NSW, Australia.
| | - Uda Y Ho
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, Brisbane, Australia
| | - Alexander James
- Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia
| | - Paul De Souza
- Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia
- School of Medicine, University of Wollongong, Wollongong, NSW, Australia
- School of Medicine, Western Sydney University, Macarthur, NSW, Australia
| | - Tara L Roberts
- Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia
- South West Sydney Clinical School, UNSW Australia, Liverpool, NSW, Australia
- School of Medicine, Western Sydney University, Macarthur, NSW, Australia
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Comprehensive Analysis of Jumonji Domain C Family from Citrus grandis and Expression Profilings in the Exocarps of “Huajuhong” (Citrus grandis “Tomentosa”) during Various Development Stages. HORTICULTURAE 2021. [DOI: 10.3390/horticulturae7120592] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Citrus grandis “Tomentosa” (“Huajuhong”) is a famous Traditional Chinese Medicine. In this study, a total of 18 jumonji C (JMJC) domain-containing proteins were identified from C. grandis. The 18 CgJMJCs were unevenly located on six chromosomes of C. grandis. Phylogenetic analysis revealed that they could be classified into five groups, namely KDM3, KDM4, KDM5, JMJC, and JMJD6. The domain structures and motif architectures in the five groups were diversified. Cis-acting elements on the promoters of 18 CgJMJC genes were also investigated, and the abscisic acid-responsive element (ABRE) was distributed on 15 CgJMJC genes. Furthermore, the expression profiles of 18 CgJMJCs members in the exocarps of three varieties of “Huajuhong”, for different developmental stages, were examined. The results were validated by quantitative real-time PCR (qRT-PCR). The present study provides a comprehensive characterization of JMJC domain-containing proteins in C. grandis and their expression patterns in the exocarps of C. grandis “Tomentosa” for three varieties with various development stages.
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8
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Lee P, Yim R, Yung Y, Chu HT, Yip PK, Gill H. Molecular Targeted Therapy and Immunotherapy for Myelodysplastic Syndrome. Int J Mol Sci 2021; 22:10232. [PMID: 34638574 PMCID: PMC8508686 DOI: 10.3390/ijms221910232] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/17/2021] [Accepted: 09/21/2021] [Indexed: 12/22/2022] Open
Abstract
Myelodysplastic syndrome (MDS) is a heterogeneous, clonal hematological disorder characterized by ineffective hematopoiesis, cytopenia, morphologic dysplasia, and predisposition to acute myeloid leukemia (AML). Stem cell genomic instability, microenvironmental aberrations, and somatic mutations contribute to leukemic transformation. The hypomethylating agents (HMAs), azacitidine and decitabine are the standard of care for patients with higher-risk MDS. Although these agents induce responses in up to 40-60% of patients, primary or secondary drug resistance is relatively common. To improve the treatment outcome, combinational therapies comprising HMA with targeted therapy or immunotherapy are being evaluated and are under continuous development. This review provides a comprehensive update of the molecular pathogenesis and immune-dysregulations involved in MDS, mechanisms of resistance to HMA, and strategies to overcome HMA resistance.
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Affiliation(s)
| | | | | | | | | | - Harinder Gill
- Division of Haematology, Medical Oncology and Haemopoietic Stem Cell Transplantation, Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China; (P.L.); (R.Y.); (Y.Y.); (H.-T.C.); (P.-K.Y.)
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Wang Y, Yang F, Shang J, He H, Yang Q. Integrative analysis reveals the prognostic value and functions of splicing factors implicated in hepatocellular carcinoma. Sci Rep 2021; 11:15175. [PMID: 34312475 PMCID: PMC8313569 DOI: 10.1038/s41598-021-94701-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 07/15/2021] [Indexed: 02/08/2023] Open
Abstract
Splicing factors (SFs) play critical roles in the pathogenesis of various cancers through regulating tumor-associated alternative splicing (AS) events. However, the clinical value and biological functions of SFs in hepatocellular carcinoma (HCC) remain obscure. In this study, we identified 40 dysregulated SFs in HCC and established a prognostic model composed of four SFs (DNAJC6, ZC3H13, IGF2BP3, DDX19B). The predictive efficiency and independence of the prognostic model were confirmed to be satisfactory. Gene Set Enrichment Analysis (GSEA) illustrated the risk score calculated by our prognostic model was significantly associated with multiple cancer-related pathways and metabolic processes. Furthermore, we constructed the SFs-AS events regulatory network and extracted 108 protein-coding genes from the network for following functional explorations. Protein–protein interaction (PPI) network delineated the potential interactions among these 108 protein-coding genes. GO and KEGG pathway analyses investigated ontology gene sets and canonical pathways enriched by these 108 protein-coding genes. Overlapping the results of GSEA and KEGG, seven pathways were identified to be potential pathways regulated by our prognostic model through triggering aberrant AS events in HCC. In conclusion, the present study established an effective prognostic model based on SFs for HCC patients. Functional explorations of SFs and SFs-associated AS events provided directions to explore biological functions and mechanisms of SFs in HCC tumorigenesis.
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Affiliation(s)
- Yue Wang
- Department of Pathogenobiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, 130021 , Jilin Province, China
| | - Fan Yang
- Department of Pathogenobiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, 130021 , Jilin Province, China
| | - Jiaqi Shang
- Department of Pathogenobiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, 130021 , Jilin Province, China
| | - Haitao He
- Department of Pathogenobiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, 130021 , Jilin Province, China
| | - Qing Yang
- Department of Pathogenobiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, 130021 , Jilin Province, China.
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Pellagatti A, Boultwood J. SF3B1 mutant myelodysplastic syndrome: Recent advances. Adv Biol Regul 2020; 79:100776. [PMID: 33358369 DOI: 10.1016/j.jbior.2020.100776] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 12/14/2020] [Indexed: 12/15/2022]
Abstract
The myelodysplastic syndromes (MDS) are common myeloid malignancies. Mutations in genes encoding different components of the spliceosome occur in more than half of all MDS patients. SF3B1 is the most frequently mutated splicing factor gene in MDS, and there is a strong association between SF3B1 mutations and the presence of ring sideroblasts in the bone marrow of MDS patients. It has been recently proposed that SF3B1 mutant MDS should be recognized as a distinct nosologic entity. Splicing factor mutations cause aberrant pre-mRNA splicing of many target genes, some of which have been shown to impact on hematopoiesis in functional studies. Emerging data show that some of the downstream effects of different mutated splicing factors converge on common cellular processes, such as hyperactivation of NF-κB signaling and increased R-loops. The aberrantly spliced target genes and the dysregulated pathways and cellular processes associated with splicing factor mutations provided the rationale for new potential therapeutic approaches to target MDS cells with mutations of SF3B1 and other splicing factors.
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Affiliation(s)
- Andrea Pellagatti
- Blood Cancer UK Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, And NIHR Oxford BRC Haematology Theme, Oxford, UK.
| | - Jacqueline Boultwood
- Blood Cancer UK Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, And NIHR Oxford BRC Haematology Theme, Oxford, UK.
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Mutations in Spliceosomal Genes PPIL1 and PRP17 Cause Neurodegenerative Pontocerebellar Hypoplasia with Microcephaly. Neuron 2020; 109:241-256.e9. [PMID: 33220177 DOI: 10.1016/j.neuron.2020.10.035] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 09/17/2020] [Accepted: 10/30/2020] [Indexed: 12/23/2022]
Abstract
Autosomal-recessive cerebellar hypoplasia and ataxia constitute a group of heterogeneous brain disorders caused by disruption of several fundamental cellular processes. Here, we identified 10 families showing a neurodegenerative condition involving pontocerebellar hypoplasia with microcephaly (PCHM). Patients harbored biallelic mutations in genes encoding the spliceosome components Peptidyl-Prolyl Isomerase Like-1 (PPIL1) or Pre-RNA Processing-17 (PRP17). Mouse knockouts of either gene were lethal in early embryogenesis, whereas PPIL1 patient mutation knockin mice showed neuron-specific apoptosis. Loss of either protein affected splicing integrity, predominantly affecting short and high GC-content introns and genes involved in brain disorders. PPIL1 and PRP17 form an active isomerase-substrate interaction, but we found that isomerase activity is not critical for function. Thus, we establish disrupted splicing integrity and "major spliceosome-opathies" as a new mechanism underlying PCHM and neurodegeneration and uncover a non-enzymatic function of a spliceosomal proline isomerase.
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12
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The transcriptome of CMML monocytes is highly inflammatory and reflects leukemia-specific and age-related alterations. Blood Adv 2020; 3:2949-2961. [PMID: 31648319 DOI: 10.1182/bloodadvances.2019000585] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 08/23/2019] [Indexed: 12/19/2022] Open
Abstract
Chronic myelomonocytic leukemia (CMML) is an aggressive myeloid neoplasm of older individuals characterized by persistent monocytosis. Somatic mutations in CMML are heterogeneous and only partially explain the variability in clinical outcomes. Recent data suggest that cardiovascular morbidity is increased in CMML and contributes to reduced survival. Clonal hematopoiesis of indeterminate potential (CHIP), the presence of mutated blood cells in hematologically normal individuals, is a precursor of age-related myeloid neoplasms and associated with increased cardiovascular risk. To isolate CMML-specific alterations from those related to aging, we performed RNA sequencing and DNA methylation profiling on purified monocytes from CMML patients and from age-matched (old) and young healthy controls. We found that the transcriptional signature of CMML monocytes is highly proinflammatory, with upregulation of multiple inflammatory pathways, including tumor necrosis factor and interleukin (IL)-6 and -17 signaling, whereas age per se does not significantly contribute to this pattern. We observed no consistent correlations between aberrant gene expression and CpG island methylation, suggesting that proinflammatory signaling in CMML monocytes is governed by multiple and complex regulatory mechanisms. We propose that proinflammatory monocytes contribute to cardiovascular morbidity in CMML patients and promote progression by selection of mutated cell clones. Our data raise questions of whether asymptomatic patients with CMML benefit from monocyte-depleting or anti-inflammatory therapies.
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McElderry J, Carrington B, Bishop K, Kim E, Pei W, Chen Z, Ramanagoudr-Bhojappa R, Prakash A, Burgess SM, Liu PP, Sood R. Splicing factor DHX15 affects tp53 and mdm2 expression via alternate splicing and promoter usage. Hum Mol Genet 2020; 28:4173-4185. [PMID: 31691804 DOI: 10.1093/hmg/ddz261] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 10/18/2019] [Accepted: 10/24/2019] [Indexed: 12/21/2022] Open
Abstract
DHX15, a DEAH box containing RNA helicase, is a splicing factor required for the last step of splicing. Recent studies identified a recurrent mutational hotspot, R222G, in DHX15 in ∼ 6% of acute myeloid leukemia (AML) patients that carry the fusion protein RUNX1-RUNX1T1 produced by t (8;21) (q22;q22). Studies using yeast mutants showed that substitution of G for the residue equivalent to R222 leads to loss of its helicase function, suggesting that it is a loss-of-function mutation. To elucidate the role of DHX15 during development, we established the first vertebrate knockout model with CRISPR/Cas9 in zebrafish. Our data showed that dhx15 expression is enriched in the brain, eyes, pectoral fin primordia, liver and intestinal bulb during embryonic development. Dhx15 deficiency leads to pleiotropic morphological phenotypes in homozygous mutant embryos starting at 3 days post fertilization (dpf) that result in lethality by 7 dpf, revealing an essential role during embryonic development. RNA-seq analysis suggested important roles of Dhx15 in chromatin and nucleosome assembly and regulation of the Mdm2-p53 pathway. Interestingly, exons corresponding to the alternate transcriptional start sites for tp53 and mdm2 were preferentially expressed in the mutant embryos, leading to significant upregulation of their alternate isoforms, Δ113p53 (orthologous to Δ133p53 isoform in human) and mdm2-P2 (isoform using distal promoter P2), respectively. We speculate that these alterations in the Mdm2-p53 pathway contribute to the development of AML in patients with t(8;21) and somatically mutated DHX15.
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Affiliation(s)
- John McElderry
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Blake Carrington
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kevin Bishop
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Erika Kim
- Oncogenesis and Development Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wuhong Pei
- Developmental Genomics Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zelin Chen
- Developmental Genomics Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ramanagouda Ramanagoudr-Bhojappa
- Cancer Genomics Unit, Cancer Genetics and Comparative Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anupam Prakash
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shawn M Burgess
- Developmental Genomics Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - P Paul Liu
- Oncogenesis and Development Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Raman Sood
- Zebrafish Core, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.,Oncogenesis and Development Section, Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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14
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Follo MY, Pellagatti A, Ratti S, Ramazzotti G, Faenza I, Fiume R, Mongiorgi S, Suh PG, McCubrey JA, Manzoli L, Boultwood J, Cocco L. Recent advances in MDS mutation landscape: Splicing and signalling. Adv Biol Regul 2019; 75:100673. [PMID: 31711974 DOI: 10.1016/j.jbior.2019.100673] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 10/28/2019] [Accepted: 11/01/2019] [Indexed: 12/13/2022]
Abstract
Recurrent cytogenetic aberrations, genetic mutations and variable gene expression have been consistently recognized in solid cancers and in leukaemia, including in Myelodysplastic Syndromes (MDS). Besides conventional cytogenetics, the growing accessibility of new techniques has led to a deeper analysis of the molecular significance of genetic variations. Indeed, gene mutations affecting splicing genes, as well as genes implicated in essential signalling pathways, play a pivotal role in MDS physiology and pathophysiology, representing potential new molecular targets for innovative therapeutic strategies.
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Affiliation(s)
- Matilde Y Follo
- Cellular Signalling Laboratory, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
| | - Andrea Pellagatti
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford and Oxford BRC Haematology Theme, Oxford, UK
| | - Stefano Ratti
- Cellular Signalling Laboratory, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Giulia Ramazzotti
- Cellular Signalling Laboratory, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Irene Faenza
- Cellular Signalling Laboratory, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Roberta Fiume
- Cellular Signalling Laboratory, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Sara Mongiorgi
- Cellular Signalling Laboratory, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Pann-Ghill Suh
- Korea Brain Research Institute, Daegu, Republic of Korea; School of Life Sciences, UNIST, Ulsan, Republic of Korea
| | - James A McCubrey
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Lucia Manzoli
- Cellular Signalling Laboratory, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Jacqueline Boultwood
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford and Oxford BRC Haematology Theme, Oxford, UK
| | - Lucio Cocco
- Cellular Signalling Laboratory, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
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15
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Splicing factor mutant myelodysplastic syndromes: Recent advances. Adv Biol Regul 2019; 75:100655. [PMID: 31558432 DOI: 10.1016/j.jbior.2019.100655] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 11/23/2022]
Abstract
The myelodysplastic syndromes (MDS) are common myeloid malignancies showing frequent progression to acute myeloid leukemia (AML). Pre-mRNA splicing is an essential cellular process carried out by the spliceosome. Mutations in splicing factor genes (including SF3B1, SRSF2, U2AF1 and ZRSR2) occur in over half of MDS patients and result in aberrant pre-mRNA splicing of many target genes, implicating aberrant spliceosome function in MDS disease pathogenesis. Recent functional studies have illuminated the impact on hematopoiesis of some aberrantly spliced target genes associated with splicing factor mutations. Emerging data show that the commonly mutated splicing factors have convergent effects on aberrant splicing of mRNAs that promote NF-κB signaling and on R-loop elevation leading to DNA damage, providing novel insights into MDS disease pathophysiology. It is recognized that the survival of splicing factor mutant cells is dependent on the presence of the wildtype allele, providing a rationale for the use of spliceosome inhibitors in splicing factor mutant MDS. Pre-clinical studies involving E7107 and H3B-8800 have shown the potential of these spliceosome inhibitors for the treatment of splicing factor mutant MDS and AML.
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16
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Desterke C, Gassama-Diagne A. Protein-protein interaction analysis highlights the role of septins in membrane enclosed lumen and mRNA processing. Adv Biol Regul 2019; 73:100635. [PMID: 31420262 DOI: 10.1016/j.jbior.2019.100635] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/01/2019] [Accepted: 07/04/2019] [Indexed: 06/10/2023]
Abstract
Septins are a family of GTP-binding proteins that assemble into non-polar filaments which can be recruited to negatively charged membranes and serve as a scaffold to recruit cytosolic proteins and cytoskeletal elements such as microtubules and actin so that they can perform their important biological functions. Human septins consist of four groups, each with 13 members, and filaments formation usually involve members from each group in specific positions. However, little is known about the molecular mechanisms that drive the binding of septins to membranes and its importance to their biological functions. Here we have built a protein-protein interaction (PPI) network around human septins and highlighted the connections with 170 partners. Functional enrichment by inference of the network of septins and their partners revealed their participation in functions consistent with some of the roles described for septins, including cell cycle, cell division and cell shape, but we also identified septin partners in these functions that had not previously been described. Interestingly, we identified important and multiple connections between septins and mRNA processing and their export from the nucleus. Analysis of the enrichment of gene ontology cellular components highlighted some important interactions between molecules involved in the spliceosome with septin 2 and septin 7 in particular. RNA splicing regulates gene expression, and through it, cell fate, development and physiology. Mutations in components of the in the splicing machinery is linked to several diseases including cancer, thus taken together, the different analyses presented here open new perspectives to elucidate the pathobiological role of septins.
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Affiliation(s)
| | - Ama Gassama-Diagne
- INSERM, Unité 1193, Villejuif, F-94800, France; Université Paris-Sud, UMR-S 1193, Villejuif, F-94800, France.
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17
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Boultwood J, Pellagatti A. The impact of spliceosome mutations in MDS. Hemasphere 2019; 3:HEMASPHERE-2019-0012. [PMID: 35309818 PMCID: PMC8925658 DOI: 10.1097/hs9.0000000000000218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/15/2019] [Accepted: 03/18/2019] [Indexed: 11/25/2022] Open
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18
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Apoptosis induction and cell cycle arrest of pladienolide B in erythroleukemia cell lines. Invest New Drugs 2019; 38:369-377. [DOI: 10.1007/s10637-019-00796-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 05/22/2019] [Indexed: 12/21/2022]
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19
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U2AF1 mutations induce oncogenic IRAK4 isoforms and activate innate immune pathways in myeloid malignancies. Nat Cell Biol 2019; 21:640-650. [PMID: 31011167 DOI: 10.1038/s41556-019-0314-5] [Citation(s) in RCA: 138] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 03/15/2019] [Indexed: 12/28/2022]
Abstract
Spliceosome mutations are common in myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML), but the oncogenic changes due to these mutations have not been identified. Here a global analysis of exon usage in AML samples revealed distinct molecular subsets containing alternative spliced isoforms of inflammatory and immune genes. Interleukin-1 receptor-associated kinase 4 (IRAK4) was the dominant alternatively spliced isoform in MDS and AML and is characterized by a longer isoform that retains exon 4, which encodes IRAK4-long (IRAK4-L), a protein that assembles with the myddosome, results in maximal activation of nuclear factor kappa-light-chain-enhancer of B cells (NF-κB) and is essential for leukaemic cell function. Expression of IRAK4-L is mediated by mutant U2 small nuclear RNA auxiliary factor 1 (U2AF1) and is associated with oncogenic signalling in MDS and AML. Inhibition of IRAK4-L abrogates leukaemic growth, particularly in AML cells with higher expression of the IRAK4-L isoform. Collectively, mutations in U2AF1 induce expression of therapeutically targetable 'active' IRAK4 isoforms and provide a genetic link to activation of chronic innate immune signalling in MDS and AML.
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20
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Response of high-risk MDS to azacitidine and lenalidomide is impacted by baseline and acquired mutations in a cluster of three inositide-specific genes. Leukemia 2019; 33:2276-2290. [PMID: 30787430 PMCID: PMC6733710 DOI: 10.1038/s41375-019-0416-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/18/2019] [Accepted: 01/22/2019] [Indexed: 12/26/2022]
Abstract
Specific myeloid-related and inositide-specific gene mutations can be linked to myelodysplastic syndromes (MDS) pathogenesis and therapy. Here, 44 higher-risk MDS patients were treated with azacitidine and lenalidomide and mutations analyses were performed at baseline and during the therapy. Results were then correlated to clinical outcome, overall survival (OS), leukemia-free-survival (LFS) and response to therapy. Collectively, 34/44 patients were considered evaluable for response, with an overall response rate of 76.25% (26/34 cases): 17 patients showed a durable response, 9 patients early lost response and 8 patients never responded. The most frequently mutated genes were ASXL1, TET2, RUNX1, and SRSF2. All patients early losing response, as well as cases never responding, acquired the same 3 point mutations during therapy, affecting respectively PIK3CD (D133E), AKT3 (D280G), and PLCG2 (Q548R) genes, that regulate cell proliferation and differentiation. Moreover, Kaplan–Meier analyses revealed that this mutated cluster was significantly associated with a shorter OS, LFS, and duration of response. All in all, a common mutated cluster affecting 3 inositide-specific genes is significantly associated with loss of response to azacitidine and lenalidomide therapy in higher risk MDS. Further studies are warranted to confirm these data and to further analyze the functional role of this 3-gene cluster.
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21
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O'Sullivan J, Mead AJ. Heterogeneity in myeloproliferative neoplasms: Causes and consequences. Adv Biol Regul 2018; 71:55-68. [PMID: 30528537 DOI: 10.1016/j.jbior.2018.11.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 11/19/2018] [Accepted: 11/20/2018] [Indexed: 01/09/2023]
Abstract
Myeloproliferative neoplasms (MPNs) are haematopoietic stem cell-derived clonal disorders characterised by proliferation of some or all myeloid lineages, depending on the subtype. MPNs are classically categorized into three disease subgroups; essential thrombocythaemia (ET), polycythaemia vera (PV) and primary myelofibrosis (PMF). The majority (>85%) of patients carry a disease-initiating or driver mutation, the most prevalent occurring in the janus kinase 2 gene (JAK2 V617F), followed by calreticulin (CALR) and myeloproliferative leukaemia virus (MPL) genes. Although these diseases are characterised by shared clinical, pathological and molecular features, one of the most challenging aspects of these disorders is the diverse clinical features which occur in each disease type, with marked variability in risks of disease complications and progression to leukaemia. A remarkable aspect of MPN biology is that the JAK2 V617F mutation, often occurring in the absence of additional mutations, generates a spectrum of phenotypes from asymptomatic ET through to aggressive MF, associated with a poor outcome. The mechanisms promoting MPN heterogeneity remain incompletely understood, but contributing factors are broad and include patient characteristics (gender, age, comorbidities and environmental exposures), additional somatic mutations, target disease-initiating cell, bone marrow microenvironment and germline genetic associations. In this review, we will address these in detail and discuss their role in heterogeneity of MPN disease phenotypes. Tailoring patient management according to the multiple different factors that influence disease phenotype may prove to be the most effective approach to modify the natural history of the disease and ultimately improve outcomes for patients.
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Affiliation(s)
- Jennifer O'Sullivan
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DS, United Kingdom.
| | - Adam J Mead
- MRC Molecular Haematology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DS, United Kingdom; NIHR Biomedical Research Centre, Churchill Hospital, Oxford, UK.
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22
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Shingai N, Harada Y, Iizuka H, Ogata Y, Doki N, Ohashi K, Hagihara M, Komatsu N, Harada H. Impact of splicing factor mutations on clinical features in patients with myelodysplastic syndromes. Int J Hematol 2018; 108:598-606. [DOI: 10.1007/s12185-018-2551-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 10/05/2018] [Accepted: 10/09/2018] [Indexed: 12/15/2022]
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23
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Chen L, Chen JY, Huang YJ, Gu Y, Qiu J, Qian H, Shao C, Zhang X, Hu J, Li H, He S, Zhou Y, Abdel-Wahab O, Zhang DE, Fu XD. The Augmented R-Loop Is a Unifying Mechanism for Myelodysplastic Syndromes Induced by High-Risk Splicing Factor Mutations. Mol Cell 2018; 69:412-425.e6. [PMID: 29395063 PMCID: PMC5957072 DOI: 10.1016/j.molcel.2017.12.029] [Citation(s) in RCA: 173] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 11/29/2017] [Accepted: 12/28/2017] [Indexed: 11/24/2022]
Abstract
Mutations in several general pre-mRNA splicing factors have been linked to myelodysplastic syndromes (MDSs) and solid tumors. These mutations have generally been assumed to cause disease by the resultant splicing defects, but different mutations appear to induce distinct splicing defects, raising the possibility that an alternative common mechanism is involved. Here we report a chain of events triggered by multiple splicing factor mutations, especially high-risk alleles in SRSF2 and U2AF1, including elevated R-loops, replication stress, and activation of the ataxia telangiectasia and Rad3-related protein (ATR)-Chk1 pathway. We further demonstrate that enhanced R-loops, opposite to the expectation from gained RNA binding with mutant SRSF2, result from impaired transcription pause release because the mutant protein loses its ability to extract the RNA polymerase II (Pol II) C-terminal domain (CTD) kinase-the positive transcription elongation factor complex (P-TEFb)-from the 7SK complex. Enhanced R-loops are linked to compromised proliferation of bone-marrow-derived blood progenitors, which can be partially rescued by RNase H overexpression, suggesting a direct contribution of augmented R-loops to the MDS phenotype.
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Affiliation(s)
- Liang Chen
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA
| | - Jia-Yu Chen
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA
| | - Yi-Jou Huang
- Department of Pathology, Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093-0651, USA
| | - Ying Gu
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA
| | - Jinsong Qiu
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA
| | - Hao Qian
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA
| | - Changwei Shao
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA
| | - Xuan Zhang
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA
| | - Jing Hu
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA
| | - Hairi Li
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA
| | - Shunmin He
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yu Zhou
- College of Life Sciences and Institute for Advanced Studies, Wuhan University, Wuhan, Hubei 40072, China
| | - Omar Abdel-Wahab
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center and Weill Cornel Medical College, New York, NY 10065, USA
| | - Dong-Er Zhang
- Department of Pathology, Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093-0651, USA.
| | - Xiang-Dong Fu
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA; Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA.
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24
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25
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Parisi S, Ratti S, Mongiorgi S, Suh PG, Manzoli L, McCubrey JA, Cocco L, Follo MY, Finelli C. Current therapy and new drugs: a road to personalized treatment of myelodysplastic syndromes. EXPERT REVIEW OF PRECISION MEDICINE AND DRUG DEVELOPMENT 2018. [DOI: 10.1080/23808993.2018.1419820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Sarah Parisi
- Department of Experimental, Diagnostic and Specialty Medicine, Institute of Hematology “L. e A. Seràgnoli”, S. Orsola-Malpighi Hospital, Bologna, Italy
| | - Stefano Ratti
- Cellular Signalling Laboratory, Institute of Human Anatomy DIBINEM, University of Bologna, Bologna, Italy
| | - Sara Mongiorgi
- Cellular Signalling Laboratory, Institute of Human Anatomy DIBINEM, University of Bologna, Bologna, Italy
| | - Pann-Ghill Suh
- School of Life Sciences, UNIST, Ulsan, Republic of Korea
| | - Lucia Manzoli
- Cellular Signalling Laboratory, Institute of Human Anatomy DIBINEM, University of Bologna, Bologna, Italy
| | - James A. McCubrey
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Lucio Cocco
- Cellular Signalling Laboratory, Institute of Human Anatomy DIBINEM, University of Bologna, Bologna, Italy
| | - Matilde Y. Follo
- Cellular Signalling Laboratory, Institute of Human Anatomy DIBINEM, University of Bologna, Bologna, Italy
| | - Carlo Finelli
- Department of Experimental, Diagnostic and Specialty Medicine, Institute of Hematology “L. e A. Seràgnoli”, S. Orsola-Malpighi Hospital, Bologna, Italy
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26
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Abstract
PURPOSE OF REVIEW Erythroid progenitors must accurately and efficiently splice thousands of pre-mRNAs as the cells undergo extensive changes in gene expression and cellular remodeling during terminal erythropoiesis. Alternative splicing choices are governed by interactions between RNA binding proteins and cis-regulatory binding motifs in the RNA. This review will focus on recent studies that define the genome-wide scope of splicing in erythroblasts and discuss what is known about its regulation. RECENT FINDINGS RNA-seq analysis of highly purified erythroblast populations has revealed an extensive program of alternative splicing of both exons and introns. During normal erythropoiesis, stage-specific splicing transitions alter the structure and abundance of protein isoforms required for optimized red cell production. Mutation or deficiency of splicing regulators underlies hematopoietic disease in myelopdysplasia syndrome patients via disrupting the splicing program. SUMMARY Erythroid progenitors execute an elaborate alternative splicing program that modulates gene expression posttranscriptionally, ultimately regulating the structure and function of the proteome in a differentiation stage-specific manner during terminal erythropoiesis. This program helps drive differentiation and ensure synthesis of the proper protein isoforms required to produce mechanically stable red cells. Mutation or deficiency of key splicing regulatory proteins disrupts the splicing program to cause disease.
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27
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Armstrong RN, Steeples V, Singh S, Sanchi A, Boultwood J, Pellagatti A. Splicing factor mutations in the myelodysplastic syndromes: target genes and therapeutic approaches. Adv Biol Regul 2017; 67:13-29. [PMID: 28986033 DOI: 10.1016/j.jbior.2017.09.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 09/19/2017] [Accepted: 09/21/2017] [Indexed: 10/25/2022]
Abstract
Mutations in splicing factor genes (SF3B1, SRSF2, U2AF1 and ZRSR2) are frequently found in patients with myelodysplastic syndromes (MDS), suggesting that aberrant spliceosome function plays a key role in the pathogenesis of MDS. Splicing factor mutations have been shown to result in aberrant splicing of many downstream target genes. Recent functional studies have begun to characterize the splicing dysfunction in MDS, identifying some key aberrantly spliced genes that are implicated in disease pathophysiology. These findings have led to the development of therapeutic strategies using splicing-modulating agents and rapid progress is being made in this field. Splicing inhibitors are promising agents that exploit the preferential sensitivity of splicing factor-mutant cells to these compounds. Here, we review the known target genes associated with splicing factor mutations in MDS, and discuss the potential of splicing-modulating therapies for these disorders.
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Affiliation(s)
- Richard N Armstrong
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and Oxford BRC Haematology Theme, Oxford, UK
| | - Violetta Steeples
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and Oxford BRC Haematology Theme, Oxford, UK
| | - Shalini Singh
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and Oxford BRC Haematology Theme, Oxford, UK
| | - Andrea Sanchi
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and Oxford BRC Haematology Theme, Oxford, UK
| | - Jacqueline Boultwood
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and Oxford BRC Haematology Theme, Oxford, UK.
| | - Andrea Pellagatti
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and Oxford BRC Haematology Theme, Oxford, UK.
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28
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Warren AJ. Molecular basis of the human ribosomopathy Shwachman-Diamond syndrome. Adv Biol Regul 2017; 67:109-127. [PMID: 28942353 PMCID: PMC6710477 DOI: 10.1016/j.jbior.2017.09.002] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 09/05/2017] [Indexed: 01/05/2023]
Abstract
Mutations that target the ubiquitous process of ribosome assembly paradoxically cause diverse tissue-specific disorders (ribosomopathies) that are often associated with an increased risk of cancer. Ribosomes are the essential macromolecular machines that read the genetic code in all cells in all kingdoms of life. Following pre-assembly in the nucleus, precursors of the large 60S and small 40S ribosomal subunits are exported to the cytoplasm where the final steps in maturation are completed. Here, I review the recent insights into the conserved mechanisms of ribosome assembly that have come from functional characterisation of the genes mutated in human ribosomopathies. In particular, recent advances in cryo-electron microscopy, coupled with genetic, biochemical and prior structural data, have revealed that the SBDS protein that is deficient in the inherited leukaemia predisposition disorder Shwachman-Diamond syndrome couples the final step in cytoplasmic 60S ribosomal subunit maturation to a quality control assessment of the structural and functional integrity of the nascent particle. Thus, study of this fascinating disorder is providing remarkable insights into how the large ribosomal subunit is functionally activated in the cytoplasm to enter the actively translating pool of ribosomes.
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MESH Headings
- Bone Marrow Diseases/metabolism
- Bone Marrow Diseases/pathology
- Cryoelectron Microscopy
- Exocrine Pancreatic Insufficiency/metabolism
- Exocrine Pancreatic Insufficiency/pathology
- Humans
- Lipomatosis/metabolism
- Lipomatosis/pathology
- Mutation
- Proteins/genetics
- Proteins/metabolism
- Ribosome Subunits, Large, Eukaryotic/genetics
- Ribosome Subunits, Large, Eukaryotic/metabolism
- Ribosome Subunits, Large, Eukaryotic/ultrastructure
- Ribosome Subunits, Small, Eukaryotic/genetics
- Ribosome Subunits, Small, Eukaryotic/metabolism
- Ribosome Subunits, Small, Eukaryotic/ultrastructure
- Shwachman-Diamond Syndrome
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Affiliation(s)
- Alan J Warren
- Cambridge Institute for Medical Research, Cambridge, UK; The Department of Haematology, University of Cambridge, Cambridge, UK; Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, UK.
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29
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Yip BH, Steeples V, Repapi E, Armstrong RN, Llorian M, Roy S, Shaw J, Dolatshad H, Taylor S, Verma A, Bartenstein M, Vyas P, Cross NC, Malcovati L, Cazzola M, Hellström-Lindberg E, Ogawa S, Smith CW, Pellagatti A, Boultwood J. The U2AF1S34F mutation induces lineage-specific splicing alterations in myelodysplastic syndromes. J Clin Invest 2017; 127:2206-2221. [PMID: 28436936 PMCID: PMC5451246 DOI: 10.1172/jci91363] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 02/21/2017] [Indexed: 12/23/2022] Open
Abstract
Mutations of the splicing factor–encoding gene U2AF1 are frequent in the myelodysplastic syndromes (MDS), a myeloid malignancy, and other cancers. Patients with MDS suffer from peripheral blood cytopenias, including anemia, and an increasing percentage of bone marrow myeloblasts. We studied the impact of the common U2AF1S34F mutation on cellular function and mRNA splicing in the main cell lineages affected in MDS. We demonstrated that U2AF1S34F expression in human hematopoietic progenitors impairs erythroid differentiation and skews granulomonocytic differentiation toward granulocytes. RNA sequencing of erythroid and granulomonocytic colonies revealed that U2AF1S34F induced a higher number of cassette exon splicing events in granulomonocytic cells than in erythroid cells. U2AF1S34F altered mRNA splicing of many transcripts that were expressed in both cell types in a lineage-specific manner. In hematopoietic progenitors, the introduction of isoform changes identified in the U2AF1S34F target genes H2AFY, encoding an H2A histone variant, and STRAP, encoding serine/threonine kinase receptor–associated protein, recapitulated phenotypes associated with U2AF1S34F expression in erythroid and granulomonocytic cells, suggesting a causal link. Furthermore, we showed that isoform modulation of H2AFY and STRAP rescues the erythroid differentiation defect in U2AF1S34F MDS cells, suggesting that splicing modulators could be used therapeutically. These data have critical implications for understanding MDS phenotypic heterogeneity and support the development of therapies targeting splicing abnormalities.
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Affiliation(s)
- Bon Ham Yip
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Violetta Steeples
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Emmanouela Repapi
- The Computational Biology Research Group, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Richard N Armstrong
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Miriam Llorian
- Department of Biochemistry, Downing Site, University of Cambridge, Cambridge, United Kingdom
| | - Swagata Roy
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Jacqueline Shaw
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Hamid Dolatshad
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Stephen Taylor
- The Computational Biology Research Group, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Amit Verma
- Albert Einstein College of Medicine, Bronx, New York, USA
| | | | - Paresh Vyas
- Medical Research Council, Molecular Hematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, and Department of Hematology, Oxford University Hospital National Health Service Trust, Oxford, United Kingdom
| | - Nicholas Cp Cross
- Faculty of Medicine, University of Southampton, Southampton, and National Genetics Reference Laboratory (Wessex), Salisbury, United Kingdom
| | - Luca Malcovati
- Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Mario Cazzola
- Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Eva Hellström-Lindberg
- Center for Hematology and Regenerative Medicine, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Seishi Ogawa
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | - Christopher Wj Smith
- Department of Biochemistry, Downing Site, University of Cambridge, Cambridge, United Kingdom
| | - Andrea Pellagatti
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Jacqueline Boultwood
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
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