201
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Abstract
Breast cancer is known to be a heterogeneous disease driven by a large repertoire of molecular abnormalities, which contribute to its diverse clinical behaviour. Despite the success of targeted therapy approaches for breast cancer patient management, there is still a lack of the molecular understanding of aggressive forms of the disease and clinical management of these patients remains difficult. The advent of high-throughput sequencing technologies has paved the way for a more complete understanding of the molecular make-up of the breast cancer genome. As such, it is becoming apparent that disruption of canonical splicing within breast cancer governs its clinical progression. In this review, we discuss the role of dysregulation of spliceosomal component genes and associated factors in the progression of breast cancer, their role in therapy resistance and the use of quantitative isoform expression as potential prognostic and predictive biomarkers with a particular focus on oestrogen receptor-positive breast cancer.
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Affiliation(s)
- Abigail Read
- The Breast Cancer Now Toby Robins Research CentreThe Institute of Cancer Research, London, UK
- Division of Molecular PathologyThe Institute of Cancer Research, London, UK
| | - Rachael Natrajan
- The Breast Cancer Now Toby Robins Research CentreThe Institute of Cancer Research, London, UK
- Division of Molecular PathologyThe Institute of Cancer Research, London, UK
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202
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PRMT5 interacts with the BCL6 oncoprotein and is required for germinal center formation and lymphoma cell survival. Blood 2018; 132:2026-2039. [PMID: 30082494 DOI: 10.1182/blood-2018-02-831438] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 07/24/2018] [Indexed: 12/21/2022] Open
Abstract
The germinal center (GC) reaction plays an important role in generating humoral immunity and is believed to give rise to most B-cell lymphomas. GC entry and exit are tightly regulated processes, controlled by the actions of transcription factors such as BCL6. Herein, we demonstrate that protein arginine methyltransferase 5 (PRMT5), a symmetric dimethyl arginine methyltransferase, is also necessary for GC formation and affinity maturation. PRMT5 contributes to GC formation and affinity maturation at least in part through its direct interaction with and methylation of BCL6 at arginine 305 (R305), a modification necessary for the full transcriptional repressive effects of BCL6. Inhibition of PRMT5 in B-cell lymphoma lines led to significant upregulation of BCL6 target genes, and the concomitant inhibition of both BCL6 and PRMT5 exhibited synergistic killing of BCL6-expressing lymphoma cells. Our studies identify PRMT5 as a novel regulator of the GC reaction and highlight the mechanistic rationale of cotargeting PRMT5 and BCL6 in lymphoma.
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203
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Calabretta S, Vogel G, Yu Z, Choquet K, Darbelli L, Nicholson TB, Kleinman CL, Richard S. Loss of PRMT5 Promotes PDGFRα Degradation during Oligodendrocyte Differentiation and Myelination. Dev Cell 2018; 46:426-440.e5. [DOI: 10.1016/j.devcel.2018.06.025] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 04/20/2018] [Accepted: 06/27/2018] [Indexed: 12/26/2022]
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204
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Xiang X, Yuan D, Liu Y, Li J, Wen Q, Kong P, Gao L, Zhang C, Gao L, Peng X, Zhang X. PIM1 overexpression in T-cell lymphomas protects tumor cells from apoptosis and confers doxorubicin resistance by upregulating c-myc expression. Acta Biochim Biophys Sin (Shanghai) 2018; 50:800-806. [PMID: 30020405 DOI: 10.1093/abbs/gmy076] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 06/08/2018] [Indexed: 12/17/2022] Open
Abstract
T-cell lymphomas (TCLs) are a malignancy characterized by tumor aggression and resistance to traditional chemotherapy. Disruption of the extrinsic cell death pathway is essential for resistance to chemotherapy. PIM1 serves as a crucial modulator in cancers. However, the role of PIM1 in TCLs remains unclear. In this study, we studied the roles of PIM1 in established T-lymphoma cell lines Jurkat and HUT-78. CCK-8 assay was conducted to evaluate cell survival and flow cytometry was performed to evaluate cell death of TCL cells. siRNAs were used to knockdown the expression of PIM1 and c-myc. qRT-PCR was used to evaluate the mRNA expression levels of c-myc and PIM1. Western blot analysis was used to evaluate the protein expression levels of PIM1, c-myc, STAT3, and phospho-STAT3. Doxorubicin was used to determine the effect of PIM1 on apoptosis. Our results showed that PIM1 expression was markedly enhanced and induced c-myc expression in TCL cells. Doxorubicin inhibited the expressions of c-myc and PIM1, and triggered the extrinsic cell death of TCLs by suppressing the JAK-STAT3 signaling pathway. Moreover, PIM1 silencing via siRNA suppressed c-myc expression, promoted the cell death of TCLs, and increased doxorubicin sensitivity. Conversely, PIM1 overexpression in TCL cells induced c-myc expression, suppressed TCL cell death, and promoted doxorubicin resistance. Collectively, our results demonstrate that PIM1 overexpression in TCLs participates in cancer cell protection from apoptosis and leads to doxorubicin resistance by inducing c-myc expression, indicating that PIM1 may be a promising target in TCL treatment.
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Affiliation(s)
- Xixi Xiang
- Center of Hematology, the Second Affiliated Hospital of Army Military Medical University, Chongqing, China
| | - Di Yuan
- Department of Educational Technology, Army Medical University, Chongqing, China
| | - Yao Liu
- Center of Hematology, the Second Affiliated Hospital of Army Military Medical University, Chongqing, China
| | - Jiali Li
- Center of Hematology, the Second Affiliated Hospital of Army Military Medical University, Chongqing, China
| | - Qin Wen
- Center of Hematology, the Second Affiliated Hospital of Army Military Medical University, Chongqing, China
| | - Peiyan Kong
- Center of Hematology, the Second Affiliated Hospital of Army Military Medical University, Chongqing, China
| | - Lei Gao
- Center of Hematology, the Second Affiliated Hospital of Army Military Medical University, Chongqing, China
| | - Cheng Zhang
- Center of Hematology, the Second Affiliated Hospital of Army Military Medical University, Chongqing, China
| | - Li Gao
- Center of Hematology, the Second Affiliated Hospital of Army Military Medical University, Chongqing, China
| | - Xiangui Peng
- Center of Hematology, the Second Affiliated Hospital of Army Military Medical University, Chongqing, China
| | - Xi Zhang
- Center of Hematology, the Second Affiliated Hospital of Army Military Medical University, Chongqing, China
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205
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Abstract
Cancer metastasis is defined as the dissemination of malignant cells from the primary tumor site, leading to colonization of distant organs and the establishment of a secondary tumor. Metastasis is frequently associated with chemoresistance and is the major cause of cancer-related mortality. Metastatic cells need to acquire the ability to resist to stresses provided by different environments, such as reactive oxygen species, shear stress, hemodynamic forces, stromal composition, and immune responses, to colonize other tissues. Hence, only a small population of cells has a metastasis-initiating potential. Several studies have revealed the misregulation of transcriptional variants during cancer progression, and many splice events can be used to distinguish between normal and tumoral tissue. These variants, which are abnormally expressed in malignant cells, contribute to an adaptive response of tumor cells and the success of the metastatic cascade, promoting an anomalous cell cycle, cellular adhesion, resistance to death, cell survival, migration and invasion. Understanding the different aspects of splicing regulation and the influence of transcriptional variants that control metastatic cells is critical for the development of therapeutic strategies. In this review, we describe how transcriptional variants contribute to metastatic competence and discuss how targeting specific isoforms may be a promising therapeutic strategy.
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Affiliation(s)
- Joice De Faria Poloni
- a Centro de Biotecnologia da Universidade Federal do Rio Grande do Sul, Departamento de Biologia Molecular e Biotecnologia , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil
| | - Diego Bonatto
- a Centro de Biotecnologia da Universidade Federal do Rio Grande do Sul, Departamento de Biologia Molecular e Biotecnologia , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil
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206
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Urbanski L, Leclair N, Anczuków O. Alternative-splicing defects in cancer: Splicing regulators and their downstream targets, guiding the way to novel cancer therapeutics. WILEY INTERDISCIPLINARY REVIEWS. RNA 2018; 9:e1476. [PMID: 29693319 PMCID: PMC6002934 DOI: 10.1002/wrna.1476] [Citation(s) in RCA: 232] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 12/14/2022]
Abstract
Defects in alternative splicing are frequently found in human tumors and result either from mutations in splicing-regulatory elements of specific cancer genes or from changes in the regulatory splicing machinery. RNA splicing regulators have emerged as a new class of oncoproteins and tumor suppressors, and contribute to disease progression by modulating RNA isoforms involved in the hallmark cancer pathways. Thus, dysregulation of alternative RNA splicing is fundamental to cancer and provides a potentially rich source of novel therapeutic targets. Here, we review the alterations in splicing regulatory factors detected in human tumors, as well as the resulting alternatively spliced isoforms that impact cancer hallmarks, and discuss how they contribute to disease pathogenesis. RNA splicing is a highly regulated process and, as such, the regulators are themselves tightly regulated. Differential transcriptional and posttranscriptional regulation of splicing factors modulates their levels and activities in tumor cells. Furthermore, the composition of the tumor microenvironment can also influence which isoforms are expressed in a given cell type and impact drug responses. Finally, we summarize current efforts in targeting alternative splicing, including global splicing inhibition using small molecules blocking the spliceosome or splicing-factor-modifying enzymes, as well as splice-switching RNA-based therapeutics to modulate cancer-specific splicing isoforms. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing.
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207
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Activation of the p53-MDM4 regulatory axis defines the anti-tumour response to PRMT5 inhibition through its role in regulating cellular splicing. Sci Rep 2018; 8:9711. [PMID: 29946150 PMCID: PMC6018746 DOI: 10.1038/s41598-018-28002-y] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 05/08/2018] [Indexed: 01/11/2023] Open
Abstract
Evasion of the potent tumour suppressor activity of p53 is one of the hurdles that must be overcome for cancer cells to escape normal regulation of cellular proliferation and survival. In addition to frequent loss of function mutations, p53 wild-type activity can also be suppressed post-translationally through several mechanisms, including the activity of PRMT5. Here we describe broad anti-proliferative activity of potent, selective, reversible inhibitors of protein arginine methyltransferase 5 (PRMT5) including GSK3326595 in human cancer cell lines representing both hematologic and solid malignancies. Interestingly, PRMT5 inhibition activates the p53 pathway via the induction of alternative splicing of MDM4. The MDM4 isoform switch and subsequent p53 activation are critical determinants of the response to PRMT5 inhibition suggesting that the integrity of the p53-MDM4 regulatory axis defines a subset of patients that could benefit from treatment with GSK3326595.
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208
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Nuclear PTEN safeguards pre-mRNA splicing to link Golgi apparatus for its tumor suppressive role. Nat Commun 2018; 9:2392. [PMID: 29921876 PMCID: PMC6008332 DOI: 10.1038/s41467-018-04760-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 05/21/2018] [Indexed: 12/11/2022] Open
Abstract
Dysregulation of pre-mRNA alternative splicing (AS) is closely associated with cancers. However, the relationships between the AS and classic oncogenes/tumor suppressors are largely unknown. Here we show that the deletion of tumor suppressor PTEN alters pre-mRNA splicing in a phosphatase-independent manner, and identify 262 PTEN-regulated AS events in 293T cells by RNA sequencing, which are associated with significant worse outcome of cancer patients. Based on these findings, we report that nuclear PTEN interacts with the splicing machinery, spliceosome, to regulate its assembly and pre-mRNA splicing. We also identify a new exon 2b in GOLGA2 transcript and the exon exclusion contributes to PTEN knockdown-induced tumorigenesis by promoting dramatic Golgi extension and secretion, and PTEN depletion significantly sensitizes cancer cells to secretion inhibitors brefeldin A and golgicide A. Our results suggest that Golgi secretion inhibitors alone or in combination with PI3K/Akt kinase inhibitors may be therapeutically useful for PTEN-deficient cancers.
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209
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Smith E, Zhou W, Shindiapina P, Sif S, Li C, Baiocchi RA. Recent advances in targeting protein arginine methyltransferase enzymes in cancer therapy. Expert Opin Ther Targets 2018; 22:527-545. [PMID: 29781349 PMCID: PMC6311705 DOI: 10.1080/14728222.2018.1474203] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION Exploration in the field of epigenetics has revealed the diverse roles of the protein arginine methyltransferase (PRMT) family of proteins in multiple disease states. These findings have led to the development of specific inhibitors and discovery of several new classes of drugs with potential to treat both benign and malignant conditions. Areas covered: We provide an overview on the role of PRMT enzymes in healthy and malignant cells, highlighting the role of arginine methylation in specific pathways relevant to cancer pathogenesis. Additionally, we describe structure and catalytic activity of PRMT and discuss the mechanisms of action of novel small molecule inhibitors of specific members of the arginine methyltransferase family. Expert opinion: As the field of PRMT biology advances, it's becoming clear that this class of enzymes is highly relevant to maintaining normal physiologic processes as well and disease pathogenesis. We discuss the potential impact of PRMT inhibitors as a broad class of drugs, including the pleiotropic effects, off target effects the need for more detailed PRMT-centric interactomes, and finally, the potential for targeting this class of enzymes in clinical development of experimental therapeutics for cancer.
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Affiliation(s)
- Emily Smith
- The Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Wei Zhou
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Polina Shindiapina
- The Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Said Sif
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, Doha, Qatar
| | - Chenglong Li
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL 32610, USA
| | - Robert A. Baiocchi
- The Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA
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210
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Protein arginine methyltransferase 5 promotes lung cancer metastasis via the epigenetic regulation of miR-99 family/FGFR3 signaling. Cancer Lett 2018; 427:38-48. [PMID: 29679612 DOI: 10.1016/j.canlet.2018.04.019] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 04/04/2018] [Accepted: 04/16/2018] [Indexed: 01/02/2023]
Abstract
Protein arginine methyltransferase 5 (PRMT5) functions as a tumor initiator to regulate several cancer progressions, such as proliferation and apoptosis, by catalyzing the symmetrical dimethylation (me2s) of arginine residues within targeted molecules. However, the exact role of PRMT5-mediated metastasis in lung cancer is not fully understood. Here, we illustrated its potential effects in lung cancer metastasis in vivo and vitro. PRMT5 was frequently overexpressed in lung tumors, and its expression was positively related to tumor stages, lymphatic metastasis and poor outcome. In this model, PRMT5 repressed the transcription of the miR-99 family by symmetrical dimethylation of histone H4R3, which increased FGFR3 expression and in turn activated Erk1/2 and Akt, leading to cell growth and metastasis in lung cancer. Furthermore, loss of PRMT5 exerted anti-metastasis effects on lung cancer progression by blocking histone-modification of miR-99 family. Overall, this study provides new insights into the PRMT5/miR-99 family/FGFR3 axis in regulating lung cancer progression and identifies PRMT5 as a promising prognostic biomarker and therapeutic target.
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211
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D'Andrea A, Gritti I, Nicoli P, Giorgio M, Doni M, Conti A, Bianchi V, Casoli L, Sabò A, Mironov A, Beznoussenko GV, Amati B. The mitochondrial translation machinery as a therapeutic target in Myc-driven lymphomas. Oncotarget 2018; 7:72415-72430. [PMID: 27635472 PMCID: PMC5341918 DOI: 10.18632/oncotarget.11719] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/25/2016] [Indexed: 12/12/2022] Open
Abstract
The oncogenic transcription factor Myc is required for the progression and maintenance of diverse tumors. This has led to the concept that Myc itself, Myc-activated gene products, or associated biological processes might constitute prime targets for cancer therapy. Here, we present an in vivo reverse-genetic screen targeting a set of 241 Myc-activated mRNAs in mouse B-cell lymphomas, unraveling a critical role for the mitochondrial ribosomal protein (MRP) Ptcd3 in tumor maintenance. Other MRP-coding genes were also up regulated in Myc-induced lymphoma, pointing to a coordinate activation of the mitochondrial translation machinery. Inhibition of mitochondrial translation with the antibiotic Tigecycline was synthetic-lethal with Myc activation, impaired respiratory activity and tumor cell survival in vitro, and significantly extended lifespan in lymphoma-bearing mice. We have thus identified a novel Myc-induced metabolic dependency that can be targeted by common antibiotics, opening new therapeutic perspectives in Myc-overexpressing tumors.
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Affiliation(s)
- Aleco D'Andrea
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy
| | - Ilaria Gritti
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy.,Present address: IRCCS San Raffaele, Functional Genomics of Cancer Unit, Division of Experimental Oncology, Milan, Italy
| | - Paola Nicoli
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy
| | - Marco Giorgio
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy
| | - Mirko Doni
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy
| | - Annalisa Conti
- Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia, Milan, Italy
| | - Valerio Bianchi
- Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia, Milan, Italy.,Present address: Hubrecht Institute-KNAW & University Medical Center Utrecht, Uppsalalaan, Utrecht, The Netherlands
| | - Lucia Casoli
- Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia, Milan, Italy
| | - Arianna Sabò
- Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia, Milan, Italy
| | - Alexandre Mironov
- The Institute of Molecular Oncology of the Italian Foundation for Cancer Research, Milan, Italy
| | - Galina V Beznoussenko
- The Institute of Molecular Oncology of the Italian Foundation for Cancer Research, Milan, Italy
| | - Bruno Amati
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy.,Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia, Milan, Italy
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212
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Jovanović KK, Roche-Lestienne C, Ghobrial IM, Facon T, Quesnel B, Manier S. Targeting MYC in multiple myeloma. Leukemia 2018; 32:1295-1306. [PMID: 29467490 DOI: 10.1038/s41375-018-0036-x] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 11/11/2017] [Accepted: 11/16/2017] [Indexed: 12/18/2022]
Abstract
Multiple myeloma (MM) is a plasma cell tumor marked by clonal evolution and preceded by a premalignant stage, which progresses via molecular pathway deregulation, including MYC activation. This activation relates to translocation or gain of the MYC locus and deregulation of upstream pathways such as IRF4, DIS3/LIN28B/let-7, or MAPK. Precision medicine is an approach to predict more accurately which treatment strategies for a particular disease will work in which groups of patients, in contrast to a "one-size-fits-all" approach. The knowledge of mechanisms responsible for MYC deregulation in MM enables identification of vulnerabilities and therapeutic targets in MYC-driven tumors. MYC can be targeted directly or indirectly, by interacting with several of its functions in cancer. Several such therapeutic strategies are evaluated in clinical trials in MM. In this review, we describe the mechanism of MYC activation in MM, the role of MYC in cancer progression, and the therapeutic options to targeting MYC.
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Affiliation(s)
| | - C Roche-Lestienne
- IRCL, INSERM UMR-S1172, Univ. Lille, Lille, France.,Institute of Medical Genetics, Univ. Lille, CHU, Lille, France
| | - I M Ghobrial
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - T Facon
- Department of Hematology, Univ. Lille,, CHU, Lille, France
| | - B Quesnel
- IRCL, INSERM UMR-S1172, Univ. Lille, Lille, France.,Department of Hematology, Univ. Lille,, CHU, Lille, France
| | - S Manier
- IRCL, INSERM UMR-S1172, Univ. Lille, Lille, France. .,Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA. .,Department of Hematology, Univ. Lille,, CHU, Lille, France.
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213
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Lombardi O, Varshney D, Phillips NM, Cowling VH. c-Myc deregulation induces mRNA capping enzyme dependency. Oncotarget 2018; 7:82273-82288. [PMID: 27756891 PMCID: PMC5347691 DOI: 10.18632/oncotarget.12701] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 10/10/2016] [Indexed: 01/24/2023] Open
Abstract
c-Myc is a potent driver of many human cancers. Since strategies for directly targeting c-Myc protein have had limited success, upstream regulators and downstream effectors of c-Myc are being investigated as alternatives for therapeutic intervention. c-Myc regulates transcription and formation of the mRNA cap, which is important for transcript maturation and translation. However, the direct mechanism by which c-Myc upregulates mRNA capping is unclear. mRNA cap formation initiates with the linkage of inverted guanosine via a triphosphate bridge to the first transcribed nucleotide, catalysed by mRNA capping enzyme (CE/RNGTT). Here we report that c-Myc increases the recruitment of catalytically active CE to RNA polymerase II and to its target genes. c-Myc-induced target gene expression, cell proliferation and cell transformation is highly dependent on CE, but only when c-Myc is deregulated. Cells retaining normal control of c-Myc expression are insensitive to repression of CE. c-Myc expression is also dependent on CE. Therefore, inhibiting CE provides an attractive route for selective therapeutic targeting of cancer cells which have acquired deregulated c-Myc.
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Affiliation(s)
- Olivia Lombardi
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Dhaval Varshney
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Nicola M Phillips
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.,School of Science and the Environment, Manchester Metropolitan University, Manchester, M15 6BH, UK
| | - Victoria H Cowling
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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214
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Groulx JF, Boudjadi S, Beaulieu JF. MYC Regulates α6 Integrin Subunit Expression and Splicing Under Its Pro-Proliferative ITGA6A Form in Colorectal Cancer Cells. Cancers (Basel) 2018; 10:42. [PMID: 29401653 PMCID: PMC5836074 DOI: 10.3390/cancers10020042] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 01/29/2018] [Accepted: 01/31/2018] [Indexed: 12/15/2022] Open
Abstract
The α6 integrin subunit (ITGA6) pre-mRNA undergoes alternative splicing to form two splicing variants, named ITGA6A and ITGA6B. In primary human colorectal cancer cells, the levels of both ITGA6 and β4 integrin subunit (ITGB4) subunits of the α6β4 integrin are increased. We previously found that the upregulation of ITGA6 is a direct consequence of the increase of the pro-proliferative ITGA6A variant. However, the mechanisms that control ITGA6 expression and splicing into the ITGA6A variant over ITGA6B in colorectal cancer cells remain poorly understood. Here, we show that the promoter activity of the ITGA6 gene is regulated by MYC. Pharmacological inhibition of MYC activity with the MYC inhibitor (MYCi) 10058-F4 or knockdown of MYC expression by short hairpin RNA (shRNA) both lead to a decrease in ITGA6 and ITGA6A levels in colorectal cancer cells, while overexpression of MYC enhances ITGA6 promoter activity. We also found that MYC inhibition decreases the epithelial splicing regulatory protein 2 (ESRP2) splicing factor at both the mRNA and protein levels. Chromatin immunoprecipitation revealed that the proximal promoter sequences of ITGA6 and ESRP2 were occupied by MYC and actively transcribed in colorectal cancer cells. Furthermore, expression studies in primary colorectal tumors and corresponding resection margins confirmed that the up-regulation of the ITGA6A subunit can be correlated with the increase in MYC and ESRP2. Taken together, our results demonstrate that the proto-oncogene MYC can regulate the promoter activation and splicing of the ITGA6 integrin gene through ESRP2 to favor the production of the pro-proliferative ITGA6A variant in colorectal cancer cells.
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Affiliation(s)
- Jean-François Groulx
- Laboratory of Intestinal Physiopathology, Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.
| | - Salah Boudjadi
- Laboratory of Intestinal Physiopathology, Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.
- Laboratory of Pathology, Cancer Molecular Pathology Section, National Cancer Institute, Bethesda, MD 20892, USA.
| | - Jean-François Beaulieu
- Laboratory of Intestinal Physiopathology, Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.
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215
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Jyotsana N, Heuser M. Exploiting differential RNA splicing patterns: a potential new group of therapeutic targets in cancer. Expert Opin Ther Targets 2017; 22:107-121. [PMID: 29235382 DOI: 10.1080/14728222.2018.1417390] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Mutations in genes associated with splicing have been found in hematologic malignancies, but also in solid cancers. Aberrant cancer specific RNA splicing either results from mutations or misexpression of the spliceosome genes directly, or from mutations in splice sites of oncogenes or tumor suppressors. Areas covered: In this review, we present molecular targets of aberrant splicing in various malignancies, information on existing and emerging therapeutics against such targets, and strategies for future drug development. Expert opinion: Alternative splicing is an important mechanism that controls gene expression, and hence pharmacologic and genetic control of aberrant alternative RNA splicing has been proposed as a potential therapy in cancer. To identify and validate aberrant RNA splicing patterns as therapeutic targets we need to (1) characterize the most common genetic aberrations of the spliceosome and of splice sites, (2) understand the dysregulated downstream pathways and (3) exploit in-vivo disease models of aberrant splicing. Antisense oligonucleotides show promising activity, but will benefit from improved delivery tools. Inhibitors of mutated splicing factors require improved specificity, as alternative and aberrant splicing are often intertwined like two sides of the same coin. In summary, targeting aberrant splicing is an early but emerging field in cancer treatment.
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Affiliation(s)
- Nidhi Jyotsana
- a Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation , Hannover Medical School , Hannover , Germany
| | - Michael Heuser
- a Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation , Hannover Medical School , Hannover , Germany
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216
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Rengasamy M, Zhang F, Vashisht A, Song WM, Aguilo F, Sun Y, Li S, Zhang W, Zhang B, Wohlschlegel JA, Walsh MJ. The PRMT5/WDR77 complex regulates alternative splicing through ZNF326 in breast cancer. Nucleic Acids Res 2017; 45:11106-11120. [PMID: 28977470 PMCID: PMC5737218 DOI: 10.1093/nar/gkx727] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 08/11/2017] [Indexed: 12/22/2022] Open
Abstract
We observed overexpression and increased intra-nuclear accumulation of the PRMT5/WDR77 in breast cancer cell lines relative to immortalized breast epithelial cells. Utilizing mass spectrometry and biochemistry approaches we identified the Zn-finger protein ZNF326, as a novel interaction partner and substrate of the nuclear PRMT5/WDR77 complex. ZNF326 is symmetrically dimethylated at arginine 175 (R175) and this modification is lost in a PRMT5 and WDR77-dependent manner. Loss of PRMT5 or WDR77 in MDA-MB-231 cells leads to defects in alternative splicing, including inclusion of A-T rich exons in target genes, a phenomenon that has previously been observed upon loss of ZNF326. We observed that the alternatively spliced transcripts of a subset of these genes, involved in proliferation and tumor cell migration like REPIN1/AP4, ST3GAL6, TRNAU1AP and PFKM are degraded upon loss of PRMT5. In summary, we have identified a novel mechanism through which the PRMT5/WDR77 complex maintains the balance between splicing and mRNA stability through methylation of ZNF326.
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Affiliation(s)
- Madhumitha Rengasamy
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Fan Zhang
- Department of Medicine, Division of Nephrology, Bioinformatics Laboratory, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Center for Life Sciences, School of Life Sciences and Technology, Harbin Institute of Technology, Harbin 150080, China
| | - Ajay Vashisht
- Departmentof Biological Chemistry and the Institute of Genomics and Proteomics, University of California, Los Angeles, CA 90095, USA
| | - Won-Min Song
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Francesca Aguilo
- Wallenberg Centre for Molecular Medicine, Department of Medical Biosciences, University of Umeå, Försörjningsvägen 19073, Umeå, Sweden
| | - Yifei Sun
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,The Mount Sinai Center for RNA Biology and Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - SiDe Li
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,The Mount Sinai Center for RNA Biology and Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Weijia Zhang
- Department of Medicine, Division of Nephrology, Bioinformatics Laboratory, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - James A Wohlschlegel
- Departmentof Biological Chemistry and the Institute of Genomics and Proteomics, University of California, Los Angeles, CA 90095, USA
| | - Martin J Walsh
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,The Mount Sinai Center for RNA Biology and Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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217
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Herdt O, Neumann A, Timmermann B, Heyd F. The cancer-associated U2AF35 470A>G (Q157R) mutation creates an in-frame alternative 5' splice site that impacts splicing regulation in Q157R patients. RNA (NEW YORK, N.Y.) 2017; 23:1796-1806. [PMID: 28893951 PMCID: PMC5689001 DOI: 10.1261/rna.061432.117] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 09/05/2017] [Indexed: 06/07/2023]
Abstract
Recent work has identified cancer-associated U2AF35 missense mutations in two zinc-finger (ZnF) domains, but little is known about Q157R/P substitutions within the second ZnF. Surprisingly, we find that the c.470A>G mutation not only leads to the Q157R substitution, but also creates an alternative 5' splice site (ss) resulting in the deletion of four amino acids (Q157Rdel). Q157P, Q157R, and Q157Rdel control alternative splicing of distinct groups of exons in cell culture and in human patients, suggesting that missplicing of different targets may contribute to cellular aberrations. Our data emphasize the importance to explore missense mutations beyond altered protein sequence.
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Affiliation(s)
- Olga Herdt
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, 14195 Berlin, Germany
| | - Alexander Neumann
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, 14195 Berlin, Germany
| | - Bernd Timmermann
- Sequencing Core Facility, Max-Planck-Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Florian Heyd
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, 14195 Berlin, Germany
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218
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219
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Zhu J, Chen Z, Yong L. Systematic profiling of alternative splicing signature reveals prognostic predictor for ovarian cancer. Gynecol Oncol 2017; 148:368-374. [PMID: 29191436 DOI: 10.1016/j.ygyno.2017.11.028] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/13/2017] [Accepted: 11/23/2017] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The majority of genes are alternatively spliced and growing evidence suggests that alternative splicing is modified in cancer and is associated with cancer progression. Systematic analysis of alternative splicing signature in ovarian cancer is lacking and greatly needed. METHODS We profiled genome-wide alternative splicing events in 408 ovarian serous cystadenocarcinoma (OV) patients in TCGA. Seven types of alternative splicing events were curated and prognostic analyses were performed with predictive models and splicing network built for OV patients. RESULTS Among 48,049 mRNA splicing events in 10,582 genes, we detected 2,611 alternative splicing events in 2,036 genes which were significant associated with overall survival of OV patients. Exon skip events were the most powerful prognostic factors among the seven types. The area under the curve of the receiver-operator characteristic curve for prognostic predictor, which was built with top significant alternative splicing events, was 0.937 at 2,000 days of overall survival, indicating powerful efficiency in distinguishing patient outcome. Interestingly, splicing correlation network suggested obvious trends in the role of splicing factors in OV. CONCLUSIONS In summary, we built powerful prognostic predictors for OV patients and uncovered interesting splicing networks which could be underlying mechanisms.
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Affiliation(s)
- Junyong Zhu
- School of Medicine, Wuhan University, Wuhan, China.
| | - Zuhua Chen
- Department of Gastrointestinal Oncology, Peking University Cancer Hospital and Institute, Beijing, China
| | - Lei Yong
- Department of Orthopedics, Peking University Third Hospital, Beijing, China
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220
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Kielkopf CL. Insights from structures of cancer-relevant pre-mRNA splicing factors. Curr Opin Genet Dev 2017; 48:57-66. [PMID: 29128695 DOI: 10.1016/j.gde.2017.10.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 10/10/2017] [Accepted: 10/13/2017] [Indexed: 12/21/2022]
Abstract
Pre-mRNA splicing factors recognize consensus signals within preliminary transcripts, and as cogs of the spliceosome machine, orchestrate the excision and rejoining of pre-mRNA regions for gene expression. Large-scale sequencing has demonstrated that mutations in key genes encoding pre-mRNA splicing factors are common among myeloid neoplasms and also occur in a variety of other cancers. This revelation offers new therapeutic opportunities to target pre-mRNA splicing vulnerabilities in hematologic and other malignancies. The mutated residues typically alter 3' splice site choice for a subset of transcripts. In this review, we highlight mechanistic insights from recent 3D structures that reveal the affected residues poised for pre-mRNA recognition.
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Affiliation(s)
- Clara L Kielkopf
- Center for RNA Biology and Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
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221
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Infantino S, Light A, O'Donnell K, Bryant V, Avery DT, Elliott M, Tangye SG, Belz G, Mackay F, Richard S, Tarlinton D. Arginine methylation catalyzed by PRMT1 is required for B cell activation and differentiation. Nat Commun 2017; 8:891. [PMID: 29026071 PMCID: PMC5638811 DOI: 10.1038/s41467-017-01009-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 08/11/2017] [Indexed: 01/11/2023] Open
Abstract
Arginine methylation catalyzed by protein arginine methyltransferases (PRMT) is a common post-translational modification in mammalian cells, regulating many important functions including cell signalling, proliferation and differentiation. Here we show the role of PRMT1 in B-cell activation and differentiation. PRMT1 expression and activity in human and mouse peripheral B cells increases in response to in vitro or in vivo activation. Deletion of the Prmt1 gene in mature B cells establishes that although the frequency and phenotype of peripheral B cell subsets seem unaffected, immune responses to T-cell-dependent and -independent antigens are substantially reduced. In vitro activation of Prmt1-deficient B cells with a variety of mitogens results in diminished proliferation, differentiation and survival, effects that are correlated with altered signal transduction from the B cell receptor. Thus PRMT1 activity in B cells is required for correct execution of multiple processes that in turn are necessary for humoral immunity. PRMT1 is an arginine methyltransferase involved in a variety of cell functions. Here the authors delete PRMT1 specifically in mature B cells to show the importance of arginine methylation for B cell proliferation, differentiation and survival, and thereby for humoral immunity.
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Affiliation(s)
- Simona Infantino
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3010, Australia. .,Department of Immunology and Pathology, Monash University, Melbourne, Victoria, 3004, Australia.
| | - Amanda Light
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Kristy O'Donnell
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3010, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Victoria, 3004, Australia
| | - Vanessa Bryant
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Danielle T Avery
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia
| | - Michael Elliott
- Sydney Medical School, University of Sydney, Sydney, NSW, 2006, Australia.,Chris O'Brien Lifehouse Cancer Centre, Royal Prince Alfred Hospital, Sydney, NSW, 2050, Australia
| | - Stuart G Tangye
- Immunology Division, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia.,St Vincent's Clinical School, Faculty of Medicine, University of NSW, Darlinghurst, NSW, 2010, Australia
| | - Gabrielle Belz
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Fabienne Mackay
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Stephane Richard
- Lady Davis Institute for Medical Research, McGill University, 3755 Cote Ste-Catherine Road, Montreal, Quebec, Canada, H3T 1E2
| | - David Tarlinton
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3010, Australia. .,Department of Immunology and Pathology, Monash University, Melbourne, Victoria, 3004, Australia.
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222
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Lin J, Lee JHJ, Paramasivam K, Pathak E, Wang Z, Pramono ZAD, Lim B, Wee KB, Surana U. Induced-Decay of Glycine Decarboxylase Transcripts as an Anticancer Therapeutic Strategy for Non-Small-Cell Lung Carcinoma. MOLECULAR THERAPY-NUCLEIC ACIDS 2017; 9:263-273. [PMID: 29246305 PMCID: PMC5675722 DOI: 10.1016/j.omtn.2017.10.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 10/03/2017] [Accepted: 10/03/2017] [Indexed: 01/04/2023]
Abstract
Self-renewing tumor-initiating cells (TICs) are thought to be responsible for tumor recurrence and chemo-resistance. Glycine decarboxylase, encoded by the GLDC gene, is reported to be overexpressed in TIC-enriched primary non-small-cell lung carcinoma (NSCLC). GLDC is a component of the mitochondrial glycine cleavage system, and its high expression is required for growth and tumorigenic capacity. Currently, there are no therapeutic agents against GLDC. As a therapeutic strategy, we have designed and tested splicing-modulating steric hindrance antisense oligonucleotides (shAONs) that efficiently induce exon skipping (half maximal inhibitory concentration [IC50] at 3.5–7 nM), disrupt the open reading frame (ORF) of GLDC transcript (predisposing it for nonsense-mediated decay), halt cell proliferation, and prevent colony formation in both A549 cells and TIC-enriched NSCLC tumor sphere cells (TS32). One candidate shAON causes 60% inhibition of tumor growth in mice transplanted with TS32. Thus, our shAONs candidates can effectively inhibit the expression of NSCLC-associated metabolic enzyme GLDC and may have promising therapeutic implications.
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Affiliation(s)
- Jing Lin
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, Singapore 138671, Singapore; Institute of High Performance Computing, A*STAR, 1 Fusionopolis Way, Singapore 138632, Singapore
| | - Jia Hui Jane Lee
- Genome Institute of Singapore, A*STAR, 60 Biopolis Street, Singapore 138672, Singapore
| | - Kathirvel Paramasivam
- Department of Pharmacology, National University of Singapore, 16 Medical Drive, Singapore 117660, Singapore
| | - Elina Pathak
- Genome Institute of Singapore, A*STAR, 60 Biopolis Street, Singapore 138672, Singapore
| | - Zhenxun Wang
- Genome Institute of Singapore, A*STAR, 60 Biopolis Street, Singapore 138672, Singapore
| | | | - Bing Lim
- Genome Institute of Singapore, A*STAR, 60 Biopolis Street, Singapore 138672, Singapore
| | - Keng Boon Wee
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, Singapore 138671, Singapore; Institute of High Performance Computing, A*STAR, 1 Fusionopolis Way, Singapore 138632, Singapore.
| | - Uttam Surana
- Department of Pharmacology, National University of Singapore, 16 Medical Drive, Singapore 117660, Singapore; Bioprocessing Technology Institute, A*STAR, 20 Biopolis Way, Singapore 138668, Singapore; Institute of Molecular and Cellular Biology, A*STAR, 61 Biopolis Drive, Singapore 138673, Singapore.
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223
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Blanc RS, Richard S. Arginine Methylation: The Coming of Age. Mol Cell 2017; 65:8-24. [PMID: 28061334 DOI: 10.1016/j.molcel.2016.11.003] [Citation(s) in RCA: 647] [Impact Index Per Article: 92.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 10/24/2016] [Accepted: 10/31/2016] [Indexed: 12/11/2022]
Abstract
Arginine methylation is a common post-translational modification functioning as an epigenetic regulator of transcription and playing key roles in pre-mRNA splicing, DNA damage signaling, mRNA translation, cell signaling, and cell fate decision. Recently, a wealth of studies using transgenic mouse models and selective PRMT inhibitors helped define physiological roles for protein arginine methyltransferases (PRMTs) linking them to diseases such as cancer and metabolic, neurodegenerative, and muscular disorders. This review describes the recent molecular advances that have been uncovered in normal and diseased mammalian cells.
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Affiliation(s)
- Roméo S Blanc
- Terry Fox Molecular Oncology Group and the Bloomfield Center for Research on Aging, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, QC H3T 1E2, Canada; Departments of Oncology and Medicine, McGill University, Montréal, QC H2W 1S6, Canada
| | - Stéphane Richard
- Terry Fox Molecular Oncology Group and the Bloomfield Center for Research on Aging, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montréal, QC H3T 1E2, Canada; Departments of Oncology and Medicine, McGill University, Montréal, QC H2W 1S6, Canada.
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224
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Jain K, Jin CY, Clarke SG. Epigenetic control via allosteric regulation of mammalian protein arginine methyltransferases. Proc Natl Acad Sci U S A 2017; 114:10101-10106. [PMID: 28874563 PMCID: PMC5617285 DOI: 10.1073/pnas.1706978114] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Arginine methylation on histones is a central player in epigenetics and in gene activation and repression. Protein arginine methyltransferase (PRMT) activity has been implicated in stem cell pluripotency, cancer metastasis, and tumorigenesis. The expression of one of the nine mammalian PRMTs, PRMT5, affects the levels of symmetric dimethylarginine (SDMA) at Arg-3 on histone H4, leading to the repression of genes which are related to disease progression in lymphoma and leukemia. Another PRMT, PRMT7, also affects SDMA levels at the same site despite its unique monomethylating activity and the lack of any evidence for PRMT7-catalyzed histone H4 Arg-3 methylation. We present evidence that PRMT7-mediated monomethylation of histone H4 Arg-17 regulates PRMT5 activity at Arg-3 in the same protein. We analyzed the kinetics of PRMT5 over a wide range of substrate concentrations. Significantly, we discovered that PRMT5 displays positive cooperativity in vitro, suggesting that this enzyme may be allosterically regulated in vivo as well. Most interestingly, monomethylation at Arg-17 in histone H4 not only raised the general activity of PRMT5 with this substrate, but also ameliorated the low activity of PRMT5 at low substrate concentrations. These kinetic studies suggest a biochemical explanation for the interplay between PRMT5- and PRMT7-mediated methylation of the same substrate at different residues and also suggest a general model for regulation of PRMTs. Elucidating the exact relationship between these two enzymes when they methylate two distinct sites of the same substrate may aid in developing therapeutics aimed at reducing PRMT5/7 activity in cancer and other diseases.
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Affiliation(s)
- Kanishk Jain
- Department of Chemistry and Biochemistry, The Molecular Biology Institute, University of California, Los Angeles, CA 90095
| | - Cyrus Y Jin
- Department of Chemistry and Biochemistry, The Molecular Biology Institute, University of California, Los Angeles, CA 90095
| | - Steven G Clarke
- Department of Chemistry and Biochemistry, The Molecular Biology Institute, University of California, Los Angeles, CA 90095
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225
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Integrative analysis of RNA polymerase II and transcriptional dynamics upon MYC activation. Genome Res 2017; 27:1658-1664. [PMID: 28904013 PMCID: PMC5630029 DOI: 10.1101/gr.226035.117] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/22/2017] [Indexed: 02/03/2023]
Abstract
Overexpression of the MYC transcription factor causes its widespread interaction with regulatory elements in the genome but leads to the up- and down-regulation of discrete sets of genes. The molecular determinants of these selective transcriptional responses remain elusive. Here, we present an integrated time-course analysis of transcription and mRNA dynamics following MYC activation in proliferating mouse fibroblasts, based on chromatin immunoprecipitation, metabolic labeling of newly synthesized RNA, extensive sequencing, and mathematical modeling. Transcriptional activation correlated with the highest increases in MYC binding at promoters. Repression followed a reciprocal scenario, with the lowest gains in MYC binding. Altogether, the relative abundance (henceforth, "share") of MYC at promoters was the strongest predictor of transcriptional responses in diverse cell types, predominating over MYC's association with the corepressor ZBTB17 (also known as MIZ1). MYC activation elicited immediate loading of RNA polymerase II (RNAPII) at activated promoters, followed by increases in pause-release, while repressed promoters showed opposite effects. Gains and losses in RNAPII loading were proportional to the changes in the MYC share, suggesting that repression by MYC may be partly indirect, owing to competition for limiting amounts of RNAPII. Secondary to the changes in RNAPII loading, the dynamics of elongation and pre-mRNA processing were also rapidly altered at MYC regulated genes, leading to the transient accumulation of partially or aberrantly processed mRNAs. Altogether, our results shed light on how overexpressed MYC alters the various phases of the RNAPII cycle and the resulting transcriptional response.
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226
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Chatzileontiadou DSM, Samiotaki M, Alexopoulou AN, Cotsiki M, Panayotou G, Stamatiadi M, Balatsos NAA, Leonidas DD, Kontou M. Proteomic Analysis of Human Angiogenin Interactions Reveals Cytoplasmic PCNA as a Putative Binding Partner. J Proteome Res 2017; 16:3606-3622. [PMID: 28777577 DOI: 10.1021/acs.jproteome.7b00335] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Human Angiogenin (hAng) is a member of the ribonuclease A superfamily and a potent inducer of neovascularization. Protein interactions of hAng in the nucleus and cytoplasm of the human umbilical vein cell line EA.hy926 have been investigated by mass spectroscopy. Data are available via ProteomeXchange with identifiers PXD006583 and PXD006584. The first gel-free analysis of hAng immunoprecipitates revealed many statistically significant potential hAng-interacting proteins involved in crucial biological pathways. Surprisingly, proliferating cell nuclear antigen (PCNA), was found to be immunoprecipitated with hAng only in the cytoplasm. The hAng-PCNA interaction and colocalization in the specific cellular compartment was validated with immunoprecipitation, immunoblotting, and immunocytochemistry. The results revealed that PCNA is predominantly localized in the cytoplasm, while hAng is distributed both in the nucleus and in the cytoplasm. hAng and PCNA colocalize in the cytoplasm, suggesting that they may interact in this compartment.
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Affiliation(s)
| | - Martina Samiotaki
- Biomedical Sciences Research Center "Alexander Fleming" , Vari 16672, Greece
| | | | - Marina Cotsiki
- Biomedical Sciences Research Center "Alexander Fleming" , Vari 16672, Greece
| | - George Panayotou
- Biomedical Sciences Research Center "Alexander Fleming" , Vari 16672, Greece
| | - Melina Stamatiadi
- Department of Biochemistry and Biotechnology, University of Thessaly , Biopolis, 41500 Larissa, Greece
| | - Nikolaos A A Balatsos
- Department of Biochemistry and Biotechnology, University of Thessaly , Biopolis, 41500 Larissa, Greece
| | - Demetres D Leonidas
- Department of Biochemistry and Biotechnology, University of Thessaly , Biopolis, 41500 Larissa, Greece
| | - Maria Kontou
- Department of Biochemistry and Biotechnology, University of Thessaly , Biopolis, 41500 Larissa, Greece
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228
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229
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230
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Lee SCW, Abdel-Wahab O. Therapeutic targeting of splicing in cancer. Nat Med 2017; 22:976-86. [PMID: 27603132 DOI: 10.1038/nm.4165] [Citation(s) in RCA: 385] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 07/13/2016] [Indexed: 02/07/2023]
Abstract
Recent studies have highlighted that splicing patterns are frequently altered in cancer and that mutations in genes encoding spliceosomal proteins, as well as mutations affecting the splicing of key cancer-associated genes, are enriched in cancer. In parallel, there is also accumulating evidence that several molecular subtypes of cancer are highly dependent on splicing function for cell survival. These findings have resulted in a growing interest in targeting splicing catalysis, splicing regulatory proteins, and/or specific key altered splicing events in the treatment of cancer. Here we present strategies that exist and that are in development to target altered dependency on the spliceosome, as well as aberrant splicing, in cancer. These include drugs to target global splicing in cancer subtypes that are preferentially dependent on wild-type splicing for survival, methods to alter post-translational modifications of splicing-regulating proteins, and strategies to modulate pathologic splicing events and protein-RNA interactions in cancer.
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Affiliation(s)
- Stanley Chun-Wei Lee
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center (MSKCC), New York, New York, USA
| | - Omar Abdel-Wahab
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center (MSKCC), New York, New York, USA.,Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
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231
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Gu Y, Zhang J, Ma X, Kim BW, Wang H, Li J, Pan Y, Xu Y, Ding L, Yang L, Guo C, Wu X, Wu J, Wu K, Gan X, Li G, Li L, Forman SJ, Chan WC, Xu R, Huang W. Stabilization of the c-Myc Protein by CAMKIIγ Promotes T Cell Lymphoma. Cancer Cell 2017; 32:115-128.e7. [PMID: 28697340 PMCID: PMC5552197 DOI: 10.1016/j.ccell.2017.06.001] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 04/19/2017] [Accepted: 06/08/2017] [Indexed: 12/20/2022]
Abstract
Although high c-Myc protein expression is observed alongside MYC amplification in some cancers, in most cases protein overexpression occurs in the absence of gene amplification, e.g., T cell lymphoma (TCL). Here, Ca2+/calmodulin-dependent protein kinase II γ (CAMKIIγ) was shown to stabilize the c-Myc protein by directly phosphorylating it at serine 62 (S62). Furthermore, CAMKIIγ was shown to be essential for tumor maintenance. Inhibition of CAMKIIγ with a specific inhibitor destabilized c-Myc and reduced tumor burden. Importantly, high CAMKIIγ levels in patient TCL specimens correlate with increased c-Myc and pS62-c-Myc levels. Together, the CAMKIIγ:c-Myc axis critically influences the development and maintenance of TCL and represents a potential therapeutic target for TCL.
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Affiliation(s)
- Ying Gu
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Jiawei Zhang
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Xiaoxiao Ma
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA; Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Byung-Wook Kim
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA; Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Hailong Wang
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Jinfan Li
- Department of Pathology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China
| | - Yi Pan
- Department of Pathology, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China
| | - Yang Xu
- Department of Hematology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China; Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China
| | - Lili Ding
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Lu Yang
- The Integrative Genomics Core, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Chao Guo
- The Integrative Genomics Core, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Xiwei Wu
- The Integrative Genomics Core, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Jun Wu
- Division of Comparative Medicine, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Kirk Wu
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Xiaoxian Gan
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Gang Li
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Ling Li
- Division of Hematopoietic Stem Cell & Leukemia Research, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Stephen J Forman
- Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA; Department of Hematology & Hematopoietic Cell Transplantation, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Wing-Chung Chan
- Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA; Department of Pathology, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Rongzhen Xu
- Department of Hematology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China; Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China.
| | - Wendong Huang
- Molecular and Cellular Biology of Cancer Program & Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA; Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA.
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232
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Genetic deletion or small-molecule inhibition of the arginine methyltransferase PRMT5 exhibit anti-tumoral activity in mouse models of MLL-rearranged AML. Leukemia 2017; 32:499-509. [PMID: 28663579 DOI: 10.1038/leu.2017.206] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 05/31/2017] [Accepted: 06/21/2017] [Indexed: 12/13/2022]
Abstract
The hematological malignancies classified as mixed lineage leukemias (MLL) harbor fusions of the MLL1 gene to partners that are members of transcriptional elongation complexes. MLL-rearranged leukemias are associated with extremely poor prognosis, and response to conventional therapies and efforts to identify molecular targets are urgently needed. Using mouse models of MLL-rearranged acute myeloid leukemia, here we show that genetic inactivation or small-molecule inhibition of the protein arginine methyltransferase PRMT5 exhibit anti-tumoral activity in MLL-fusion protein-driven transformation. Genome-wide transcriptional analysis revealed that inhibition of PRMT5 methyltransferase activity overrides the differentiation block in leukemia cells without affecting the expression of MLL-fusion direct oncogenic targets. Furthermore, we find that this differentiation block is mediated by transcriptional silencing of the cyclin-dependent kinase inhibitor p21 (CDKN1a) gene in leukemia cells. Our study provides pre-clinical rationale for targeting PRMT5 using small-molecule inhibitors in the treatment of leukemias harboring MLL rearrangements.
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233
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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: 64] [Impact Index Per Article: 9.1] [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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234
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Gao G, Dhar S, Bedford MT. PRMT5 regulates IRES-dependent translation via methylation of hnRNP A1. Nucleic Acids Res 2017; 45:4359-4369. [PMID: 28115626 PMCID: PMC5416833 DOI: 10.1093/nar/gkw1367] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 12/20/2016] [Accepted: 12/29/2016] [Indexed: 01/19/2023] Open
Abstract
The type II arginine methyltransferase PRMT5 is responsible for the symmetric dimethylation of histone to generate the H3R8me2s and H4R3me2s marks, which correlate with the repression of transcription. However, the protein level of a number of genes (MEP50, CCND1, MYC, HIF1a, MTIF and CDKN1B) are reported to be downregulated by the loss of PRMT5, while their mRNA levels remain unchanged, which is counterintuitive for PRMT5's proposed role as a transcription repressor. We noticed that the majority of the genes regulated by PRMT5, at the posttranscriptional level, express mRNA containing an internal ribosome entry site (IRES). Using an IRES-dependent reporter system, we established that PRMT5 facilitates the translation of a subset of IRES-containing genes. The heterogeneous nuclear ribonucleoprotein, hnRNP A1, is an IRES transacting factor (ITAF) that regulates the IRES-dependent translation of Cyclin D1 and c-Myc. We showed that hnRNP A1 is methylated by PRMT5 on two residues, R218 and R225, and that this methylation facilitates the interaction of hnRNP A1 with IRES RNA to promote IRES-dependent translation. This study defines a new role for PRMT5 regulation of cellular protein levels, which goes beyond the known functions of PRMT5 as a transcription and splicing regulator.
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Affiliation(s)
- Guozhen Gao
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX 78957, USA
| | - Surbhi Dhar
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX 78957, USA
| | - Mark T Bedford
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, TX 78957, USA
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235
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Joshi P, Halene S, Abdel-Wahab O. How do messenger RNA splicing alterations drive myelodysplasia? Blood 2017; 129:2465-2470. [PMID: 28348147 PMCID: PMC5418633 DOI: 10.1182/blood-2017-02-692715] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 03/23/2017] [Indexed: 12/21/2022] Open
Abstract
Mutations in RNA splicing factors are the single most common class of genetic alterations in myelodysplastic syndrome (MDS) patients. Although much has been learned about how these mutations affect splicing at a global- and transcript-specific level, critical questions about the role of these mutations in MDS development and maintenance remain. Here we present the questions to be addressed in order to understand the unique enrichment of these mutations in MDS.
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Affiliation(s)
- Poorval Joshi
- Section of Hematology, Yale Comprehensive Cancer Center and Department of Internal Medicine, Yale University School of Medicine, New Haven, CT; and
| | - Stephanie Halene
- Section of Hematology, Yale Comprehensive Cancer Center and Department of Internal Medicine, Yale University School of Medicine, New Haven, CT; and
| | - Omar Abdel-Wahab
- Human Oncology and Pathogenesis Program and Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY
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236
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Emerging Role for Methylation in Multiple Sclerosis: Beyond DNA. Trends Mol Med 2017; 23:546-562. [PMID: 28478950 DOI: 10.1016/j.molmed.2017.04.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 03/29/2017] [Accepted: 04/10/2017] [Indexed: 12/29/2022]
Abstract
Multiple Sclerosis (MS) is a chronic inflammatory disease of the central nervous system. The inflammatory and neurodegenerative pathways driving MS are modulated by DNA, lysine, and arginine methylation, as evidenced by studies made possible by novel tools for methylation detection or loss of function. We present evidence that MS is associated with genetic variants and metabolic changes that impact on methylation. Further, we comprehensively review current understanding of how methylation can impact on central nervous system (CNS) resilience and neuroregenerative potential, as well as inflammatory versus regulatory T helper (Th) cell balance. These findings are discussed in the context of therapeutic relevance for MS, with broad implications in other neurologic and immune-mediated diseases.
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237
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Jenkins JL, Kielkopf CL. Splicing Factor Mutations in Myelodysplasias: Insights from Spliceosome Structures. Trends Genet 2017; 33:336-348. [PMID: 28372848 PMCID: PMC5447463 DOI: 10.1016/j.tig.2017.03.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 02/28/2017] [Accepted: 03/02/2017] [Indexed: 01/08/2023]
Abstract
Somatic mutations of pre-mRNA splicing factors recur among patients with myelodysplastic syndrome (MDS) and related malignancies. Although these MDS-relevant mutations alter the splicing of a subset of transcripts, the mechanisms by which these single amino acid substitutions change gene expression remain controversial. New structures of spliceosome intermediates and associated protein complexes shed light on the molecular interactions mediated by 'hotspots' of the SF3B1 and U2AF1 pre-mRNA splicing factors. The frequently mutated SF3B1 residues contact the pre-mRNA splice site. Based on structural homology with other spliceosome subunits, and recent findings of altered RNA binding by mutant U2AF1 proteins, we suggest that affected U2AF1 residues also contact pre-mRNA. Altered pre-mRNA recognition emerges as a molecular theme among MDS-relevant mutations of pre-mRNA splicing factors.
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Affiliation(s)
- Jermaine L Jenkins
- Center for RNA Biology and Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Clara L Kielkopf
- Center for RNA Biology and Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
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238
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Kozlovski I, Siegfried Z, Amar-Schwartz A, Karni R. The role of RNA alternative splicing in regulating cancer metabolism. Hum Genet 2017; 136:1113-1127. [PMID: 28429085 DOI: 10.1007/s00439-017-1803-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 04/13/2017] [Indexed: 12/12/2022]
Abstract
Tumor cells alter their metabolism by a wide array of mechanisms to promote growth and proliferation. Dysregulated expression and/or somatic mutations of key components of the glycolytic pathway/TCA cycle as well as other metabolic pathways allow tumor cells to improve their ability to survive harsh conditions such as hypoxia and the presence of reactive oxygen species, as well as the ability to obtain nutrients to increase lipids, protein, and nucleic acids biogenesis. Approximately 95% of the human protein encoding genes undergo alternative splicing (AS), a regulated process of gene expression that greatly diversifies the proteome by creating multiple proteins from a single gene. In recent years, a growing body of evidence suggests that unbalanced AS, the formation of certain pro-tumorigenic isoforms and the reduction of anti-tumorigenic isoforms, is implicated in a variety of cancers. It is becoming increasingly clear that cancer-associated AS contributes to increased growth and proliferation, partially due to effects on metabolic reprogramming. Here, we summarize the known roles of AS in regulating cancer metabolism. We present evidence supporting the idea that AS, in many types of cancer, acts as a molecular switch that alters metabolism to drive tumorigenesis. We propose that the elucidation of misregulated AS and its downstream effects on cancer metabolism emphasizes the need for new therapeutic approaches aiming to modulate the splicing machinery to selectively target cancer cells.
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Affiliation(s)
- Itamar Kozlovski
- Department of Biochemistry and Molecular Biology, IMRIC, Hebrew University-Hadassah Medical School, Ein Karem, 91120, Jerusalem, Israel
| | - Zahava Siegfried
- Department of Biochemistry and Molecular Biology, IMRIC, Hebrew University-Hadassah Medical School, Ein Karem, 91120, Jerusalem, Israel
| | - Adi Amar-Schwartz
- Department of Biochemistry and Molecular Biology, IMRIC, Hebrew University-Hadassah Medical School, Ein Karem, 91120, Jerusalem, Israel
| | - Rotem Karni
- Department of Biochemistry and Molecular Biology, IMRIC, Hebrew University-Hadassah Medical School, Ein Karem, 91120, Jerusalem, Israel.
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239
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Gallego-Paez LM, Bordone MC, Leote AC, Saraiva-Agostinho N, Ascensão-Ferreira M, Barbosa-Morais NL. Alternative splicing: the pledge, the turn, and the prestige : The key role of alternative splicing in human biological systems. Hum Genet 2017; 136:1015-1042. [PMID: 28374191 PMCID: PMC5602094 DOI: 10.1007/s00439-017-1790-y] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 03/25/2017] [Indexed: 02/06/2023]
Abstract
Alternative pre-mRNA splicing is a tightly controlled process conducted by the spliceosome, with the assistance of several regulators, resulting in the expression of different transcript isoforms from the same gene and increasing both transcriptome and proteome complexity. The differences between alternative isoforms may be subtle but enough to change the function or localization of the translated proteins. A fine control of the isoform balance is, therefore, needed throughout developmental stages and adult tissues or physiological conditions and it does not come as a surprise that several diseases are caused by its deregulation. In this review, we aim to bring the splicing machinery on stage and raise the curtain on its mechanisms and regulation throughout several systems and tissues of the human body, from neurodevelopment to the interactions with the human microbiome. We discuss, on one hand, the essential role of alternative splicing in assuring tissue function, diversity, and swiftness of response in these systems or tissues, and on the other hand, what goes wrong when its regulatory mechanisms fail. We also focus on the possibilities that splicing modulation therapies open for the future of personalized medicine, along with the leading techniques in this field. The final act of the spliceosome, however, is yet to be fully revealed, as more knowledge is needed regarding the complex regulatory network that coordinates alternative splicing and how its dysfunction leads to disease.
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Affiliation(s)
- L M Gallego-Paez
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - M C Bordone
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - A C Leote
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - N Saraiva-Agostinho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - M Ascensão-Ferreira
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - N L Barbosa-Morais
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
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240
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Thompson N, Adams DJ, Ranzani M. Synthetic lethality: emerging targets and opportunities in melanoma. Pigment Cell Melanoma Res 2017; 30:183-193. [PMID: 28097822 PMCID: PMC5396340 DOI: 10.1111/pcmr.12573] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 01/11/2017] [Indexed: 02/06/2023]
Abstract
Great progress has been made in the treatment of melanoma through use of targeted therapies and immunotherapy. One approach that has not been fully explored is synthetic lethality, which exploits somatically acquired changes, usually driver mutations, to specifically kill tumour cells. We outline the various approaches that may be applied to identify synthetic lethal interactions and define how these interactions may drive drug discovery efforts.
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Affiliation(s)
- Nicola Thompson
- Experimental Cancer Genetics, The Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire, UK
| | - David J Adams
- Experimental Cancer Genetics, The Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire, UK
| | - Marco Ranzani
- Experimental Cancer Genetics, The Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire, UK
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241
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Abstract
The organization of the chromatin structure is essential for maintaining cell-type-specific gene expression and therefore for cell identity. This structure is highly dynamic and is regulated by a large number of chromatin-associated proteins that are required for normal development and differentiation. Recurrent somatic mutations have been found with high frequency in genes coding for chromatin-associated proteins in cancer, and several of these are required for cancer maintenance. In this review, we discuss recent advances in understanding the role of chromatin-associated proteins in transcription, development, and cancer. Specifically, we focus on selected examples of proteins belonging to the histone methyltransferase, histone demethylase, or bromodomain families, for which specific small molecule inhibitors have been developed and are in either preclinical or clinical trials.
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Affiliation(s)
- Kristian Helin
- Biotech Research and Innovation Centre (BRIC),
- Centre for Epigenetics, and
- The Danish Stem Cell Center (DanStem), University of Copenhagen, 2200 Copenhagen, Denmark
| | - Saverio Minucci
- Department of Experimental Oncology,
- Drug Development Program, European Institute of Oncology, 20139 Milan, Italy
- Department of Biosciences, University of Milan, 20100 Milan, Italy
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242
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Tian N, Li J, Shi J, Sui G. From General Aberrant Alternative Splicing in Cancers and Its Therapeutic Application to the Discovery of an Oncogenic DMTF1 Isoform. Int J Mol Sci 2017; 18:ijms18030191. [PMID: 28257090 PMCID: PMC5372486 DOI: 10.3390/ijms18030191] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 01/03/2017] [Accepted: 01/10/2017] [Indexed: 12/20/2022] Open
Abstract
Alternative pre-mRNA splicing is a crucial process that allows the generation of diversified RNA and protein products from a multi-exon gene. In tumor cells, this mechanism can facilitate cancer development and progression through both creating oncogenic isoforms and reducing the expression of normal or controllable protein species. We recently demonstrated that an alternative cyclin D-binding myb-like transcription factor 1 (DMTF1) pre-mRNA splicing isoform, DMTF1β, is increasingly expressed in breast cancer and promotes mammary tumorigenesis in a transgenic mouse model. Aberrant pre-mRNA splicing is a typical event occurring for many cancer-related functional proteins. In this review, we introduce general aberrant pre-mRNA splicing in cancers and discuss its therapeutic application using our recent discovery of the oncogenic DMTF1 isoform as an example. We also summarize new insights in designing novel targeting strategies of cancer therapies based on the understanding of deregulated pre-mRNA splicing mechanisms.
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Affiliation(s)
- Na Tian
- College of Life Science, Northeast Forestry University, Harbin 150040, China.
| | - Jialiang Li
- College of Life Science, Northeast Forestry University, Harbin 150040, China.
| | - Jinming Shi
- College of Life Science, Northeast Forestry University, Harbin 150040, China.
| | - Guangchao Sui
- College of Life Science, Northeast Forestry University, Harbin 150040, China.
- Department of Cancer Biology and Comprehensive Cancer Center, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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243
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Eckstein M, Eleazer R, Rea M, Fondufe-Mittendorf Y. Epigenomic reprogramming in inorganic arsenic-mediated gene expression patterns during carcinogenesis. REVIEWS ON ENVIRONMENTAL HEALTH 2017; 32:93-103. [PMID: 27701139 DOI: 10.1515/reveh-2016-0025] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 08/08/2016] [Indexed: 05/22/2023]
Abstract
Arsenic is a ubiquitous metalloid that is not mutagenic but is carcinogenic. The mechanism(s) by which arsenic causes cancer remain unknown. To date, several mechanisms have been proposed, including the arsenic-induced generation of reactive oxygen species (ROS). However, it is also becoming evident that inorganic arsenic (iAs) may exert its carcinogenic effects by changing the epigenome, and thereby modifying chromatin structure and dynamics. These epigenetic changes alter the accessibility of gene regulatory factors to DNA, resulting in specific changes in gene expression both at the levels of transcription initiation and gene splicing. In this review, we discuss recent literature reports describing epigenetic changes induced by iAs exposure and the possible epigenetic mechanisms underlying these changes.
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244
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Abstract
MDM4, an essential negative regulator of the P53 tumor suppressor, is frequently overexpressed in cancer cells that harbor a wild-type P53. By a mechanism based on alternative splicing, the MDM4 gene generates two mutually exclusive isoforms: MDM4-FL, which encodes the full-length MDM4 protein, and a shorter splice variant called MDM4-S. Previous results suggested that the MDM4-S isoform could be an important driver of tumor development. In this short review, we discuss a recent set of data indicating that MDM4-S is more likely a passenger isoform during tumorigenesis and that targeting MDM4 splicing to prevent MDM4-FL protein expression appears as a promising strategy to reactivate p53 in cancer cells. The benefits and risks associated with this strategy are also discussed.
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245
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Li Y, Sun N, Lu Z, Sun S, Huang J, Chen Z, He J. Prognostic alternative mRNA splicing signature in non-small cell lung cancer. Cancer Lett 2017; 393:40-51. [PMID: 28223168 DOI: 10.1016/j.canlet.2017.02.016] [Citation(s) in RCA: 144] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/04/2017] [Accepted: 02/12/2017] [Indexed: 12/20/2022]
Abstract
Alternative splicing provides a major mechanism to generate protein diversity. Increasing evidence suggests a link of dysregulation of splicing associated with cancer. Genome-wide alternative splicing profiling in lung cancer remains largely unstudied. We generated alternative splicing profiles in 491 lung adenocarcinoma (LUAD) and 471 lung squamous cell carcinoma (LUSC) patients in TCGA using RNA-seq data, prognostic models and splicing networks were built by integrated bioinformatics analysis. A total of 3691 and 2403 alternative splicing events were significantly associated with patient survival in LUAD and LUSC, respectively, including EGFR, CD44, PIK3C3, RRAS2, MAPKAP1 and FGFR2. The area under the curve of the receiver-operator characteristic curve for prognostic predictor in NSCLC was 0.817 at 2000 days of overall survival which were also over 0.8 in LUAD and LUSC, separately. Interestingly, splicing correlation networks uncovered opposite roles of splicing factors in LUAD and LUSC. We created prognostic predictors based on alternative splicing events with high performances for risk stratification in NSCLC patients and uncovered interesting splicing networks in LUAD and LUSC which could be underlying mechanisms.
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MESH Headings
- Adenocarcinoma/genetics
- Adenocarcinoma/metabolism
- Adenocarcinoma/mortality
- Adenocarcinoma/pathology
- Adenocarcinoma of Lung
- Alternative Splicing
- Area Under Curve
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Carcinoma, Non-Small-Cell Lung/genetics
- Carcinoma, Non-Small-Cell Lung/metabolism
- Carcinoma, Non-Small-Cell Lung/mortality
- Carcinoma, Non-Small-Cell Lung/pathology
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/metabolism
- Carcinoma, Squamous Cell/mortality
- Carcinoma, Squamous Cell/pathology
- Computational Biology
- Databases, Genetic
- Gene Expression Profiling/methods
- Gene Expression Regulation, Neoplastic
- Gene Regulatory Networks
- Genome-Wide Association Study
- Humans
- Kaplan-Meier Estimate
- Lung Neoplasms/genetics
- Lung Neoplasms/metabolism
- Lung Neoplasms/mortality
- Lung Neoplasms/pathology
- Prognosis
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- ROC Curve
- Signal Transduction
- Time Factors
- Transcriptome
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Affiliation(s)
- Yuan Li
- Department of Thoracic Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - Nan Sun
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Zhiliang Lu
- Department of Thoracic Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - Shouguo Sun
- Department of Thoracic Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - Jianbing Huang
- Department of Thoracic Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - Zhaoli Chen
- Department of Thoracic Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China.
| | - Jie He
- Department of Thoracic Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China.
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246
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Suda K, Rozeboom L, Yu H, Ellison K, Rivard CJ, Mitsudomi T, Hirsch FR. Potential effect of spliceosome inhibition in small cell lung cancer irrespective of the MYC status. PLoS One 2017; 12:e0172209. [PMID: 28192473 PMCID: PMC5305228 DOI: 10.1371/journal.pone.0172209] [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: 01/02/2017] [Accepted: 02/01/2017] [Indexed: 11/18/2022] Open
Abstract
Small cell lung cancer (SCLC) is a highly aggressive malignancy with few therapeutic advances in the treatment in recent decades. Based on a recent study that identified the spliceosome as a therapeutic vulnerability in MYC-driven breast cancers, we evaluated the efficacy of a spliceosome inhibitor in SCLC cell lines and analyzed the correlation with MYC status. Among 23 SCLC cell lines examined, eight showed high MYC protein expression (> 80% positive cells) by immunohistochemistry (IHC), while 10 cell lines demonstrated no staining for MYC. The remaining five cell lines showed weak staining (< 40% positive cells). All four cell lines that were previously demonstrated to have MYC gene amplification were positive for MYC by IHC. Four cell lines with high MYC expression and four with low MYC expression were used in further analysis. A spliceosome inhibitor, pladienolide B, showed high efficacy (IC50 < 12nM) in all eight cell lines tested, irrespective of the MYC IHC or MYC gene amplification status. We observed that the four cell lines with higher sensitivity to the spliceosome inhibitor were established from patients with prior chemotherapy. Therefore we chronically treated H1048 cells, that were established from a treatment-naïve patient, with cisplatin for 4 weeks, and found that H1048-cisplatin treated cells became more sensitive to pladienolide B. In conclusion, our in vitro results indicate that spliceosome inhibitors would be promising molecular target drugs in SCLC irrespective of the MYC status, especially in the second-line settings after an effective front-line chemotherapy.
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Affiliation(s)
- Kenichi Suda
- Division of Medical Oncology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America.,Division of Thoracic Surgery, Department of Surgery, Kindai University Faculty of Medicine, Osaka-Sayama, Japan
| | - Leslie Rozeboom
- Division of Medical Oncology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Hui Yu
- Division of Medical Oncology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Kim Ellison
- Division of Medical Oncology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Christopher J Rivard
- Division of Medical Oncology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Tetsuya Mitsudomi
- Division of Thoracic Surgery, Department of Surgery, Kindai University Faculty of Medicine, Osaka-Sayama, Japan
| | - Fred R Hirsch
- Division of Medical Oncology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
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247
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Webb LM, Amici SA, Jablonski KA, Savardekar H, Panfil AR, Li L, Zhou W, Peine K, Karkhanis V, Bachelder EM, Ainslie KM, Green PL, Li C, Baiocchi RA, Guerau-de-Arellano M. PRMT5-Selective Inhibitors Suppress Inflammatory T Cell Responses and Experimental Autoimmune Encephalomyelitis. THE JOURNAL OF IMMUNOLOGY 2017; 198:1439-1451. [PMID: 28087667 DOI: 10.4049/jimmunol.1601702] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 12/15/2016] [Indexed: 12/22/2022]
Abstract
In the autoimmune disease multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), expansion of pathogenic, myelin-specific Th1 cell populations drives active disease; selectively targeting this process may be the basis for a new therapeutic approach. Previous studies have hinted at a role for protein arginine methylation in immune responses, including T cell-mediated autoimmunity and EAE. However, a conclusive role for the protein arginine methyltransferase (PRMT) enzymes that catalyze these reactions has been lacking. PRMT5 is the main PRMT responsible for symmetric dimethylation of arginine residues of histones and other proteins. PRMT5 drives embryonic development and cancer, but its role in T cells, if any, has not been investigated. In this article, we show that PRMT5 is an important modulator of CD4+ T cell expansion. PRMT5 was transiently upregulated during maximal proliferation of mouse and human memory Th cells. PRMT5 expression was regulated upstream by the NF-κB pathway, and it promoted IL-2 production and proliferation. Blocking PRMT5 with novel, highly selective small molecule PRMT5 inhibitors severely blunted memory Th expansion, with preferential suppression of Th1 cells over Th2 cells. In vivo, PRMT5 blockade efficiently suppressed recall T cell responses and reduced inflammation in delayed-type hypersensitivity and clinical disease in EAE mouse models. These data implicate PRMT5 in the regulation of adaptive memory Th cell responses and suggest that PRMT5 inhibitors may be a novel therapeutic approach for T cell-mediated inflammatory disease.
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Affiliation(s)
- Lindsay M Webb
- Division of Medical Laboratory Science, School of Health and Rehabilitation Sciences, College of Medicine, The Ohio State University, Columbus, OH 43210.,Biomedical Sciences Graduate Program, College of Medicine, The Ohio State University, Columbus, OH 43210
| | - Stephanie A Amici
- Division of Medical Laboratory Science, School of Health and Rehabilitation Sciences, College of Medicine, The Ohio State University, Columbus, OH 43210
| | - Kyle A Jablonski
- Division of Medical Laboratory Science, School of Health and Rehabilitation Sciences, College of Medicine, The Ohio State University, Columbus, OH 43210
| | - Himanshu Savardekar
- Division of Medical Laboratory Science, School of Health and Rehabilitation Sciences, College of Medicine, The Ohio State University, Columbus, OH 43210
| | - Amanda R Panfil
- College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210
| | - Linsen Li
- Division of Medicinal Chemistry and Pharmacology, College of Pharmacy, The Ohio State University, Columbus OH 43210
| | - Wei Zhou
- Division of Medicinal Chemistry and Pharmacology, College of Pharmacy, The Ohio State University, Columbus OH 43210
| | - Kevin Peine
- Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599
| | - Vrajesh Karkhanis
- Division of Hematology, Department of Internal Medicine, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH 43210
| | - Eric M Bachelder
- Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599
| | - Kristy M Ainslie
- Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599
| | - Patrick L Green
- College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210
| | - Chenglong Li
- Division of Medicinal Chemistry and Pharmacology, College of Pharmacy, The Ohio State University, Columbus OH 43210
| | - Robert A Baiocchi
- Division of Hematology, Department of Internal Medicine, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH 43210
| | - Mireia Guerau-de-Arellano
- Division of Medical Laboratory Science, School of Health and Rehabilitation Sciences, College of Medicine, The Ohio State University, Columbus, OH 43210; .,Institute of Behavioral Medicine Research, College of Medicine, The Ohio State University, Columbus, OH 43210.,Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH 43210; and.,Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210
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249
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Abstract
The functional capacity of cells is defined by the transcriptome. Many recent studies have identified variations in the transcriptome of tumors due to alternative splicing changes, as well as mutations in splicing factors and regulatory signals in most tumor types. Some of these alterations have been linked to tumor progression, metastasis, therapy resistance, and other oncogenic processes. Here, we describe the different mechanisms that drive splicing changes in tumors and their impact in cancer. Motivated by the current evidence, we propose a model whereby a subset of the splicing patterns contributes to the definition of specific tumor phenotypes, and may hold potential for the development of novel clinical biomarkers and therapeutic approaches.
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Affiliation(s)
- Babita Singh
- a Pompeu Fabra University, PRBB , Barcelona , Spain
| | - Eduardo Eyras
- a Pompeu Fabra University, PRBB , Barcelona , Spain.,b ICREA , Barcelona , Spain
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250
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Splicing factor gene mutations in hematologic malignancies. Blood 2016; 129:1260-1269. [PMID: 27940478 DOI: 10.1182/blood-2016-10-692400] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 11/25/2016] [Indexed: 01/27/2023] Open
Abstract
Alternative splicing generates a diversity of messenger RNA (mRNA) transcripts from a single mRNA precursor and contributes to the complexity of our proteome. Splicing is perturbed by a variety of mechanisms in cancer. Recurrent mutations in splicing factors have emerged as a hallmark of several hematologic malignancies. Splicing factor mutations tend to occur in the founding clone of myeloid cancers, and these mutations have recently been identified in blood cells from normal, healthy elderly individuals with clonal hematopoiesis who are at increased risk of subsequently developing a hematopoietic malignancy, suggesting that these mutations contribute to disease initiation. Splicing factor mutations change the pattern of splicing in primary patient and mouse hematopoietic cells and alter hematopoietic differentiation and maturation in animal models. Recent developments in this field are reviewed here, with an emphasis on the clinical consequences of splicing factor mutations, mechanistic insights from animal models, and implications for development of novel therapies targeting the precursor mRNA splicing pathway.
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