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Ascensão-Ferreira M, Martins-Silva R, Saraiva-Agostinho N, Barbosa-Morais NL. betAS: intuitive analysis and visualization of differential alternative splicing using beta distributions. RNA (NEW YORK, N.Y.) 2024; 30:337-353. [PMID: 38278530 PMCID: PMC10946425 DOI: 10.1261/rna.079764.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 01/15/2024] [Indexed: 01/28/2024]
Abstract
Next-generation RNA sequencing allows alternative splicing (AS) quantification with unprecedented resolution, with the relative inclusion of an alternative sequence in transcripts being commonly quantified by the proportion of reads supporting it as percent spliced-in (PSI). However, PSI values do not incorporate information about precision, proportional to the respective AS events' read coverage. Beta distributions are suitable to quantify inclusion levels of alternative sequences, using reads supporting their inclusion and exclusion as surrogates for the two distribution shape parameters. Each such beta distribution has the PSI as its mean value and is narrower when the read coverage is higher, facilitating the interpretability of its precision when plotted. We herein introduce a computational pipeline, based on beta distributions accurately modeling PSI values and their precision, to quantitatively and visually compare AS between groups of samples. Our methodology includes a differential splicing significance metric that compromises the magnitude of intergroup differences, the estimation uncertainty in individual samples, and the intragroup variability, being therefore suitable for multiple-group comparisons. To make our approach accessible and clear to both noncomputational and computational biologists, we developed betAS, an interactive web app and user-friendly R package for visual and intuitive differential splicing analysis from read count data.
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Affiliation(s)
- Mariana Ascensão-Ferreira
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa 1649-028, Portugal
| | - Rita Martins-Silva
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa 1649-028, Portugal
| | - Nuno Saraiva-Agostinho
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, United Kingdom
| | - Nuno L Barbosa-Morais
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa 1649-028, Portugal
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Ruta V, Naro C, Pieraccioli M, Leccese A, Archibugi L, Cesari E, Panzeri V, Allgöwer C, Arcidiacono PG, Falconi M, Carbone C, Tortora G, Borrelli F, Attili F, Spada C, Quero G, Alfieri S, Doglioni C, Kleger A, Capurso G, Sette C. An alternative splicing signature defines the basal-like phenotype and predicts worse clinical outcome in pancreatic cancer. Cell Rep Med 2024; 5:101411. [PMID: 38325381 PMCID: PMC10897606 DOI: 10.1016/j.xcrm.2024.101411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 11/19/2023] [Accepted: 01/12/2024] [Indexed: 02/09/2024]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is characterized by extremely poor prognosis. PDAC presents with molecularly distinct subtypes, with the basal-like one being associated with enhanced chemoresistance. Splicing dysregulation contributes to PDAC; however, its involvement in subtype specification remains elusive. Herein, we uncover a subtype-specific splicing signature associated with prognosis in PDAC and the splicing factor Quaking (QKI) as a determinant of the basal-like signature. Single-cell sequencing analyses highlight QKI as a marker of the basal-like phenotype. QKI represses splicing events associated with the classical subtype while promoting basal-like events associated with shorter survival. QKI favors a plastic, quasi-mesenchymal phenotype that supports migration and chemoresistance in PDAC organoids and cell lines, and its expression is elevated in high-grade primary tumors and metastatic lesions. These studies identify a splicing signature that defines PDAC subtypes and indicate that QKI promotes an undifferentiated, plastic phenotype, which renders PDAC cells chemoresistant and adaptable to environmental changes.
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Affiliation(s)
- Veronica Ruta
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy
| | - Chiara Naro
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy; Fondazione Policlinico A. Gemelli IRCCS, 00168 Rome, Italy
| | - Marco Pieraccioli
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy; Fondazione Policlinico A. Gemelli IRCCS, 00168 Rome, Italy
| | - Adriana Leccese
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy
| | - Livia Archibugi
- Pancreato-Biliary Endoscopy and Endosonography Division, Pancreas Translational and Clinical Research Center, San Raffaele Scientific Institute IRCCS, 20132 Milan, Italy
| | | | - Valentina Panzeri
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy
| | - Chantal Allgöwer
- Institute for Molecular Oncology and Stem Cell Biology, Ulm University Hospital, 89081 Ulm, Germany
| | - Paolo Giorgio Arcidiacono
- Pancreato-Biliary Endoscopy and Endosonography Division, Pancreas Translational and Clinical Research Center, San Raffaele Scientific Institute IRCCS, 20132 Milan, Italy; Vita-Salute San Raffaele University, 20132 Milan, Italy
| | - Massimo Falconi
- Vita-Salute San Raffaele University, 20132 Milan, Italy; Pancreas and Transplantation Surgical Division, Pancreas Translational and Clinical Research Center, San Raffaele Scientific Institute IRCCS, 20132 Milan, Italy
| | | | - Giampaolo Tortora
- Fondazione Policlinico A. Gemelli IRCCS, 00168 Rome, Italy; Medical Oncology, Catholic University of the Sacred Heart, 00168 Rome, Italy
| | | | - Fabia Attili
- Fondazione Policlinico A. Gemelli IRCCS, 00168 Rome, Italy
| | | | - Giuseppe Quero
- Fondazione Policlinico A. Gemelli IRCCS, 00168 Rome, Italy; Gemelli Pancreatic Advanced Research Center (CRMPG), Catholic University of the Sacred Heart, 00168 Rome, Italy
| | - Sergio Alfieri
- Fondazione Policlinico A. Gemelli IRCCS, 00168 Rome, Italy; Gemelli Pancreatic Advanced Research Center (CRMPG), Catholic University of the Sacred Heart, 00168 Rome, Italy
| | - Claudio Doglioni
- Vita-Salute San Raffaele University, 20132 Milan, Italy; Division of Pathology, Pancreas Translational and Clinical Research Center, San Raffaele Scientific Institute IRCCS, 20132 Milan, Italy
| | - Alexander Kleger
- Institute for Molecular Oncology and Stem Cell Biology, Ulm University Hospital, 89081 Ulm, Germany; Division of Interdisciplinary Pancreatology, Department of Internal Medicine I, Ulm University Hospital, 89081 Ulm, Germany
| | - Gabriele Capurso
- Pancreato-Biliary Endoscopy and Endosonography Division, Pancreas Translational and Clinical Research Center, San Raffaele Scientific Institute IRCCS, 20132 Milan, Italy; Vita-Salute San Raffaele University, 20132 Milan, Italy
| | - Claudio Sette
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy; Fondazione Policlinico A. Gemelli IRCCS, 00168 Rome, Italy.
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3
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Webster NJG, Kumar D, Wu P. Dysregulation of RNA splicing in early non-alcoholic fatty liver disease through hepatocellular carcinoma. Sci Rep 2024; 14:2500. [PMID: 38291075 PMCID: PMC10828381 DOI: 10.1038/s41598-024-52237-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 01/16/2024] [Indexed: 02/01/2024] Open
Abstract
While changes in RNA splicing have been extensively studied in hepatocellular carcinoma (HCC), no studies have systematically investigated changes in RNA splicing during earlier liver disease. Mouse studies have shown that disruption of RNA splicing can trigger liver disease and we have shown that the splicing factor SRSF3 is decreased in the diseased human liver, so we profiled RNA splicing in liver samples from twenty-nine individuals with no-history of liver disease or varying degrees of non-alcoholic fatty liver disease (NAFLD). We compared our results with three publicly available transcriptome datasets that we re-analyzed for splicing events (SEs). We found many changes in SEs occurred during early liver disease, with fewer events occurring with the onset of inflammation and fibrosis. Many of these early SEs were enriched for SRSF3-dependent events and were associated with SRSF3 binding sites. Mapping the early and late changes to gene ontologies and pathways showed that the genes harboring these early SEs were involved in normal liver metabolism, whereas those harboring late SEs were involved in inflammation, fibrosis and proliferation. We compared the SEs with HCC data from the TCGA and observed that many of these early disease SEs are found in HCC samples and, furthermore, are correlated with disease survival. Changes in splicing factor expression are also observed, which may be associated with distinct subsets of the SEs. The maintenance of these SEs through the multi-year oncogenic process suggests that they may be causative. Understanding the role of these splice variants in metabolic liver disease progression may shed light on the triggers of liver disease progression and the pathogenesis of HCC.
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Affiliation(s)
- Nicholas J G Webster
- Jennifer Moreno VA Medical Center, San Diego, CA, 92161, USA.
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, CA, 92093, USA.
- Moores Cancer Center, University of California, San Diego, CA, 92093, USA.
| | - Deepak Kumar
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, CA, 92093, USA
| | - Panyisha Wu
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, CA, 92093, USA
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4
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Theodoropoulou K, Spel L, Zaffalon L, Delacrétaz M, Hofer M, Martinon F. NLRP3 leucine-rich repeats control induced and spontaneous inflammasome activation in cryopyrin-associated periodic syndrome. J Allergy Clin Immunol 2023; 151:222-232.e9. [PMID: 36075321 DOI: 10.1016/j.jaci.2022.08.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 07/15/2022] [Accepted: 08/11/2022] [Indexed: 02/04/2023]
Abstract
BACKGROUND The cryopyrin-associated periodic syndromes (CAPS) comprise a group of rare autoinflammatory diseases caused by gain-of-function mutations in the NLRP3 gene. NLRP3 contains a leucine-rich repeats (LRR) domain with a highly conserved exonic organization that is subjected to extensive alternative splicing. Aberrant NLRP3 inflammasome assembly in CAPS causes chronic inflammation; however, the mechanisms regulating inflammasome function remain unclear. OBJECTIVE We aimed to elucidate the mechanisms regulating NLRP3-mediated autoinflammation in human disease, characterizing the role of LRR in inflammasome activation. METHODS We analyzed sequence read archive data to characterize the pattern of NLRP3 splicing in human monocytes and investigated the role of each LRR-coding exon in inflammasome regulation in genetically modified U937 cells representing CAPS and healthy conditions. RESULTS We detected a range of NLRP3 splice variants in human primary cells and monocytic cell lines, including 2 yet-undescribed splice variants. We observe that lipopolysaccharides affect the abundance of certain splice variants, suggesting that they may regulate NLRP3 activation by affecting alternative splicing. We showed that exons 4, 5, 7, and 9 are essential for inflammasome function, both in the context of wild-type NLRP3 activation by the agonist molecule nigericin and in a model of CAPS-mediated NLRP3 inflammasome assembly. Moreover, the SGT1-NLRP3 interaction is decreased in nonfunctional variants, suggesting that alternative splicing may regulate the recruitment of proteins that facilitate inflammasome assembly. CONCLUSION These findings demonstrate the contribution of the LRR domain in inflammasome function and suggest that navigating LRR exon usage within NLRP3 is sufficient to dampen inflammasome assembly in CAPS.
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Affiliation(s)
- Katerina Theodoropoulou
- Department of Immunobiology, University of Lausanne; Pediatric Unit of Immunology, Allergology and Rheumatology, University Hospital of Lausanne, Lausanne
| | - Lotte Spel
- Department of Immunobiology, University of Lausanne
| | - Léa Zaffalon
- Department of Immunobiology, University of Lausanne
| | | | - Michaël Hofer
- Pediatric Unit of Immunology, Allergology and Rheumatology, University Hospital of Lausanne, Lausanne
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Del Giudice M, Foster JG, Peirone S, Rissone A, Caizzi L, Gaudino F, Parlato C, Anselmi F, Arkell R, Guarrera S, Oliviero S, Basso G, Rajan P, Cereda M. FOXA1 regulates alternative splicing in prostate cancer. Cell Rep 2022; 40:111404. [PMID: 36170835 PMCID: PMC9532847 DOI: 10.1016/j.celrep.2022.111404] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 05/28/2022] [Accepted: 09/01/2022] [Indexed: 11/25/2022] Open
Abstract
Dysregulation of alternative splicing in prostate cancer is linked to transcriptional programs activated by AR, ERG, FOXA1, and MYC. Here, we show that FOXA1 functions as the primary orchestrator of alternative splicing dysregulation across 500 primary and metastatic prostate cancer transcriptomes. We demonstrate that FOXA1 binds to the regulatory regions of splicing-related genes, including HNRNPK and SRSF1. By controlling trans-acting factor expression, FOXA1 exploits an "exon definition" mechanism calibrating alternative splicing toward dominant isoform production. This regulation especially impacts splicing factors themselves and leads to a reduction of nonsense-mediated decay (NMD)-targeted isoforms. Inclusion of the NMD-determinant FLNA exon 30 by FOXA1-controlled oncogene SRSF1 promotes cell growth in vitro and predicts disease recurrence. Overall, we report a role for FOXA1 in rewiring the alternative splicing landscape in prostate cancer through a cascade of events from chromatin access, to splicing factor regulation, and, finally, to alternative splicing of exons influencing patient survival.
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Affiliation(s)
- Marco Del Giudice
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - John G Foster
- Centre for Cancer Cell and Molecular Biology, Barts Cancer Institute, Cancer Research UK Barts Centre, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Serena Peirone
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Alberto Rissone
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - Livia Caizzi
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - Federica Gaudino
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - Caterina Parlato
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - Francesca Anselmi
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Department of Life Science and System Biology, Università degli Studi di Torino, via Accademia Albertina 13, 10123 Turin, Italy
| | - Rebecca Arkell
- Centre for Cancer Cell and Molecular Biology, Barts Cancer Institute, Cancer Research UK Barts Centre, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Simonetta Guarrera
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - Salvatore Oliviero
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Department of Life Science and System Biology, Università degli Studi di Torino, via Accademia Albertina 13, 10123 Turin, Italy
| | - Giuseppe Basso
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Candiolo Cancer Institute, FPO-IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy
| | - Prabhakar Rajan
- Centre for Cancer Cell and Molecular Biology, Barts Cancer Institute, Cancer Research UK Barts Centre, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK; Division of Surgery and Interventional Science, University College London, Charles Bell House, 3 Road Floor, 43-45 Foley Street, London W1W 7TS, UK; The Alan Turing Institute, British Library, 96 Euston Road, London NW1 2DB, UK; Department of Urology, Barts Health NHS Trust, the Royal London Hospital, Whitechapel Road, London E1 1BB, UK; Department of Uro-oncology, University College London NHS Foundation Trust, 47 Wimpole Street, London W1G 8SE, UK.
| | - Matteo Cereda
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov. le 142, km 3.95, 10060 Candiolo (TO), Italy; Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy.
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6
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Kumar D, Das M, Oberg A, Sahoo D, Wu P, Sauceda C, Jih L, Ellies LG, Langiewicz MT, Sen S, Webster NJG. Hepatocyte Deletion of IGF2 Prevents DNA Damage and Tumor Formation in Hepatocellular Carcinoma. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2105120. [PMID: 35615981 PMCID: PMC9313545 DOI: 10.1002/advs.202105120] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 03/18/2022] [Indexed: 05/12/2023]
Abstract
Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Serine-arginine rich splicing factor 3 (SRSF3) plays a critical role in hepatocyte function and its loss in mice promotes chronic liver damage and leads to HCC. Hepatocyte-specific SRSF3 knockout mice (SKO mice) also overexpress insulin-like growth factor 2 (IGF2). In the present study, double deletion of Igf2 and Srsf3 (DKO mice) prevents hepatic fibrosis and inflammation, and completely prevents tumor formation, and is associated with decreased proliferation, apoptosis and DNA damage, and restored DNA repair enzyme expression. This is confirmed in vitro, where IGF2 treatment of HepG2 hepatoma cells decreases DNA repair enzyme expression and causes DNA damage. Tumors from the SKO mice also show mutational signatures consistent with homologous recombination and mismatch repair defects. Analysis of frozen human samples shows that SRSF3 protein is decreased sixfold in HCC compared to normal liver tissue but SRSF3 mRNA is increased. Looking at public TCGA data, HCC patients having high SRSF3 mRNA expression show poor survival, as do patients with alterations in known SRSF3-dependent splicing events. The results indicate that IGF2 overexpression in conjunction with reduced SRSF3 splicing activity could be a major cause of DNA damage and driver of liver cancer.
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Affiliation(s)
- Deepak Kumar
- Research and Development ServiceVA San Diego Healthcare SystemSan DiegoCA92161USA
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Manasi Das
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Alexis Oberg
- Research and Development ServiceVA San Diego Healthcare SystemSan DiegoCA92161USA
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Debashis Sahoo
- Division of Genome Information Sciences, Department of PediatricsUniversity of California San DiegoLa JollaCA92093USA
| | - Panyisha Wu
- Research and Development ServiceVA San Diego Healthcare SystemSan DiegoCA92161USA
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Consuelo Sauceda
- Research and Development ServiceVA San Diego Healthcare SystemSan DiegoCA92161USA
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Lily Jih
- Research and Development ServiceVA San Diego Healthcare SystemSan DiegoCA92161USA
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Lesley G. Ellies
- Division of Cancer Biology Research, Department of PathologyUniversity of California San DiegoLa JollaCA92093USA
- Moores Cancer CenterUniversity of California San DiegoLa JollaCA92093USA
| | - Magda T. Langiewicz
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Supriya Sen
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
| | - Nicholas J. G. Webster
- Research and Development ServiceVA San Diego Healthcare SystemSan DiegoCA92161USA
- Division of Endocrinology and Metabolism, Department of MedicineUniversity of California San DiegoLa JollaCA92093USA
- Moores Cancer CenterUniversity of California San DiegoLa JollaCA92093USA
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7
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Gallego-Paez LM, Mauer J. DJExpress: An Integrated Application for Differential Splicing Analysis and Visualization. FRONTIERS IN BIOINFORMATICS 2022; 2:786898. [PMID: 36304260 PMCID: PMC9580925 DOI: 10.3389/fbinf.2022.786898] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 02/08/2022] [Indexed: 12/22/2022] Open
Abstract
RNA-seq analysis of alternative pre-mRNA splicing has facilitated an unprecedented understanding of transcriptome complexity in health and disease. However, despite the availability of countless bioinformatic pipelines for transcriptome-wide splicing analysis, the use of these tools is often limited to expert bioinformaticians. The need for high computational power, combined with computational outputs that are complicated to visualize and interpret present obstacles to the broader research community. Here we introduce DJExpress, an R package for differential expression analysis of transcriptomic features and expression-trait associations. To determine gene-level differential junction usage as well as associations between junction expression and molecular/clinical features, DJExpress uses raw splice junction counts as input data. Importantly, DJExpress runs on an average laptop computer and provides a set of interactive and intuitive visualization formats. In contrast to most existing pipelines, DJExpress can handle both annotated and de novo identified splice junctions, thereby allowing the quantification of novel splice events. Moreover, DJExpress offers a web-compatible graphical interface allowing the analysis of user-provided data as well as the visualization of splice events within our custom database of differential junction expression in cancer (DJEC DB). DJEC DB includes not only healthy and tumor tissue junction expression data from TCGA and GTEx repositories but also cancer cell line data from the DepMap project. The integration of DepMap functional genomics data sets allows association of junction expression with molecular features such as gene dependencies and drug response profiles. This facilitates identification of cancer cell models for specific splicing alterations that can then be used for functional characterization in the lab. Thus, DJExpress represents a powerful and user-friendly tool for exploration of alternative splicing alterations in RNA-seq data, including multi-level data integration of alternative splicing signatures in healthy tissue, tumors and cancer cell lines.
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Affiliation(s)
| | - Jan Mauer
- *Correspondence: Lina Marcela Gallego-Paez, ; Jan Mauer,
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8
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Differential Expression of CREM/ICER Isoforms Is Associated with the Spontaneous Control of HIV Infection. mBio 2022; 13:e0197921. [PMID: 35041523 PMCID: PMC8725591 DOI: 10.1128/mbio.01979-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A rare subset of HIV-infected individuals, termed elite controllers (ECs), can maintain long-term control over HIV replication in the absence of antiretroviral therapy (ART). To elucidate the biological mechanism of resistance to HIV replication at the molecular and cellular levels, we performed RNA sequencing and identified alternative splicing variants from ECs, HIV-infected individuals undergoing ART, ART-naive HIV-infected individuals, and healthy controls. We identified differential gene expression patterns that are specific to ECs and may influence HIV resistance, including alternative RNA splicing and exon usage variants of the CREM/ICER gene (cyclic AMP [cAMP]-responsive element modulator/inducible cAMP early repressors). The knockout and knockdown of specific ICER exons that were found to be upregulated in ECs resulted in significantly increased HIV infection in a CD4+ T cell line and primary CD4+ T cells. Overexpression of ICER isoforms decreased HIV infection in primary CD4+ T cells. Furthermore, ICER regulated HIV long terminal repeat (LTR) promoter activity in a Tat-dependent manner. Together, these results suggest that ICER is an HIV host factor that may contribute to the HIV resistance of ECs. These findings will help elucidate the mechanisms of HIV control by ECs and may yield a new approach for treatment of HIV. IMPORTANCE A small group of HIV-infected individuals, termed elite controllers (ECs), display control of HIV replication in the absence of antiretroviral therapy (ART). However, the mechanism of ECs' resistance to HIV replication is not clear. In our work, we found an increased expression of specific, small isoforms of ICER in ECs. Further experiments proved that ICER is a robust host factor to regulate viral replication. Furthermore, we found that ICER regulates HIV LTR promoter activity in a Tat-dependent manner. These findings suggest that ICER is related to spontaneous control of HIV infection in ECs. This study may help elucidate a novel target for treatment of HIV.
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9
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Yan Q, Chen Y, Liu H, Li G, Liang C, Hao Z. Effects of alternative splicing events and transcriptome changes on kidney stone formation. Urolithiasis 2022; 50:131-140. [PMID: 34997271 PMCID: PMC8956516 DOI: 10.1007/s00240-021-01293-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 11/18/2021] [Indexed: 12/18/2022]
Abstract
During the development of urinary stone disease, the formation of tiny crystals that adhere to the renal tubular epithelium induces epithelial cell damage. This damage and repair of the epithelium is associated with the establishment of more crystal adhesion sites, which in turn stimulates further crystal adhesion and, eventually, stone formation. Deposited crystals typically cause changes in epithelial cell gene expression, such as transcriptome changes and alternative splicing events. Although considered important for regulating gene expression, alternative splicing has not been reported in studies related to kidney stones. To date, whether alternative splicing events are involved in the regulation of stone formation and whether crystallographic cell interactions are regulated by alternative splicing at the transcriptional level have remained unknown. Therefore, we conducted RNA sequencing and alternative splicing-related bioassays by modeling the in vitro stone environment. Many alternative splicing events were associated with crystallographic cell interactions. Moreover, these events regulated transcription and significantly affected the capacity of crystals to adhere to renal tubular epithelial cells and regulate apoptosis.
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Affiliation(s)
- Qunsheng Yan
- Department of Urology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.,Institute of Urology, Anhui Medical University, Hefei, China.,Anhui Province Key Laboratory of Genitourinary Diseases, Anhui Medical University, Hefei, China
| | - Yang Chen
- Department of Urology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.,Institute of Urology, Anhui Medical University, Hefei, China.,Anhui Province Key Laboratory of Genitourinary Diseases, Anhui Medical University, Hefei, China
| | - Haoran Liu
- Department of Urology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.,Institute of Urology, Anhui Medical University, Hefei, China.,Anhui Province Key Laboratory of Genitourinary Diseases, Anhui Medical University, Hefei, China
| | - Guoxiang Li
- Department of Urology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.,Institute of Urology, Anhui Medical University, Hefei, China.,Anhui Province Key Laboratory of Genitourinary Diseases, Anhui Medical University, Hefei, China
| | - Chaozhao Liang
- Department of Urology, The First Affiliated Hospital of Anhui Medical University, Hefei, China. .,Institute of Urology, Anhui Medical University, Hefei, China. .,Anhui Province Key Laboratory of Genitourinary Diseases, Anhui Medical University, Hefei, China.
| | - Zongyao Hao
- Department of Urology, The First Affiliated Hospital of Anhui Medical University, Hefei, China. .,Institute of Urology, Anhui Medical University, Hefei, China. .,Anhui Province Key Laboratory of Genitourinary Diseases, Anhui Medical University, Hefei, China.
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10
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Naro C, De Musso M, Delle Monache F, Panzeri V, de la Grange P, Sette C. The oncogenic kinase NEK2 regulates an RBFOX2-dependent pro-mesenchymal splicing program in triple-negative breast cancer cells. J Exp Clin Cancer Res 2021; 40:397. [PMID: 34930366 PMCID: PMC8686545 DOI: 10.1186/s13046-021-02210-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 12/06/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Triple-negative breast cancer (TNBC) is the most heterogeneous and malignant subtype of breast cancer (BC). TNBC is defined by the absence of expression of estrogen, progesterone and HER2 receptors and lacks efficacious targeted therapies. NEK2 is an oncogenic kinase that is significantly upregulated in TNBC, thereby representing a promising therapeutic target. NEK2 localizes in the nucleus and promotes oncogenic splice variants in different cancer cells. Notably, alternative splicing (AS) dysregulation has recently emerged as a featuring trait of TNBC that contributes to its aggressive phenotype. METHODS To investigate whether NEK2 modulates TNBC transcriptome we performed RNA-sequencing analyses in a representative TNBC cell line (MDA-MB-231) and results were validated in multiple TNBC cell lines. Bioinformatics and functional analyses were carried out to elucidate the mechanism of splicing regulation by NEK2. Data from The Cancer Genome Atlas were mined to evaluate the potential of NEK2-sensitive exons as markers to identify the TNBC subtype and to assess their prognostic value. RESULTS Transcriptome analysis revealed a widespread impact of NEK2 on the transcriptome of TNBC cells, with 1830 AS events that are susceptible to its expression. NEK2 regulates the inclusion of cassette exons in splice variants that discriminate TNBC from other BC and that correlate with poor prognosis, suggesting that this kinase contributes to the TNBC-specific splicing program. NEK2 elicits its effects by modulating the expression of the splicing factor RBFOX2, a well-known regulator of epithelial to mesenchymal transition (EMT). Accordingly, NEK2 splicing-regulated genes are enriched in functional terms related to cell adhesion and contractile cytoskeleton and NEK2 depletion in mesenchymal TNBC cells induces phenotypic and molecular traits typical of epithelial cells. Remarkably, depletion of select NEK2-sensitive splice-variants that are prognostic in TNBC patients is sufficient to interfere with TNBC cell morphology and motility, suggesting that NEK2 orchestrates a pro-mesenchymal splicing program that modulates migratory and invasive properties of TNBC cells. CONCLUSIONS Our study uncovers an extensive splicing program modulated by NEK2 involving splice variants that confer an invasive phenotype to TNBCs and that might represent, together with NEK2 itself, valuable therapeutic targets for this disease.
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Affiliation(s)
- Chiara Naro
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168, Rome, Italy.
- Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy.
| | - Monica De Musso
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
| | - Francesca Delle Monache
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
| | - Valentina Panzeri
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
| | | | - Claudio Sette
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168, Rome, Italy.
- Fondazione Santa Lucia, IRCCS, Rome, Italy.
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11
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Namba S, Ueno T, Kojima S, Kobayashi K, Kawase K, Tanaka Y, Inoue S, Kishigami F, Kawashima S, Maeda N, Ogawa T, Hazama S, Togashi Y, Ando M, Shiraishi Y, Mano H, Kawazu M. Transcript-targeted analysis reveals isoform alterations and double-hop fusions in breast cancer. Commun Biol 2021; 4:1320. [PMID: 34811492 PMCID: PMC8608905 DOI: 10.1038/s42003-021-02833-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 11/02/2021] [Indexed: 12/22/2022] Open
Abstract
Although transcriptome alteration is an essential driver of carcinogenesis, the effects of chromosomal structural alterations on the cancer transcriptome are not yet fully understood. Short-read transcript sequencing has prevented researchers from directly exploring full-length transcripts, forcing them to focus on individual splice sites. Here, we develop a pipeline for Multi-Sample long-read Transcriptome Assembly (MuSTA), which enables construction of a transcriptome from long-read sequence data. Using the constructed transcriptome as a reference, we analyze RNA extracted from 22 clinical breast cancer specimens. We identify a comprehensive set of subtype-specific and differentially used isoforms, which extended our knowledge of isoform regulation to unannotated isoforms including a short form TNS3. We also find that the exon-intron structure of fusion transcripts depends on their genomic context, and we identify double-hop fusion transcripts that are transcribed from complex structural rearrangements. For example, a double-hop fusion results in aberrant expression of an endogenous retroviral gene, ERVFRD-1, which is normally expressed exclusively in placenta and is thought to protect fetus from maternal rejection; expression is elevated in several TCGA samples with ERVFRD-1 fusions. Our analyses provide direct evidence that full-length transcript sequencing of clinical samples can add to our understanding of cancer biology and genomics in general.
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Affiliation(s)
- Shinichi Namba
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, 104-0045, Japan
- Department of Statistical Genetics, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Toshihide Ueno
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, 104-0045, Japan
| | - Shinya Kojima
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, 104-0045, Japan
| | - Kenya Kobayashi
- Department of Head and Neck Oncology, National Cancer Center Hospital, Tokyo, 104-0045, Japan
| | - Katsushige Kawase
- Division of Cell Therapy, Chiba Cancer Center, Research Institute, Chiba, 260-8717, Japan
| | - Yosuke Tanaka
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, 104-0045, Japan
| | - Satoshi Inoue
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, 104-0045, Japan
| | - Fumishi Kishigami
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, 104-0045, Japan
| | - Shusuke Kawashima
- Division of Cell Therapy, Chiba Cancer Center, Research Institute, Chiba, 260-8717, Japan
| | - Noriko Maeda
- Department of Gastroenterological, Breast and Endocrine Surgery, Yamaguchi University Graduate School of Medicine, Yamaguchi, 755-8505, Japan
| | - Tomoko Ogawa
- Department of Breast Surgery, Mie University Hospital, Mie, 514-8507, Japan
| | - Shoichi Hazama
- Department of Translational Research and Developmental Therapeutics against Cancer, Yamaguchi University Graduate School of Medicine, Yamaguchi, 755-8505, Japan
| | - Yosuke Togashi
- Division of Cell Therapy, Chiba Cancer Center, Research Institute, Chiba, 260-8717, Japan
| | - Mizuo Ando
- Department of Otolaryngology, Head and Neck Surgery, The University of Tokyo Hospital, Tokyo, 113-8654, Japan
| | - Yuichi Shiraishi
- Division of Genome Analysis Platform Development, National Cancer Center Research Institute, Tokyo, 104-0045, Japan
| | - Hiroyuki Mano
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, 104-0045, Japan
| | - Masahito Kawazu
- Division of Cellular Signaling, National Cancer Center Research Institute, Tokyo, 104-0045, Japan.
- Division of Cell Therapy, Chiba Cancer Center, Research Institute, Chiba, 260-8717, Japan.
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12
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MDM4 Isoform Expression in Melanoma Supports an Oncogenic Role for MDM4-A. J Skin Cancer 2021; 2021:3087579. [PMID: 34697572 PMCID: PMC8541850 DOI: 10.1155/2021/3087579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/04/2021] [Accepted: 10/05/2021] [Indexed: 11/17/2022] Open
Abstract
The p53 tumor suppressor integrates upstream signals such as DNA damage and active oncogenes to initiate cell cycle arrest or apoptosis. This response is critical to halting inappropriate growth signals. As such, p53 activity is lost in cancer. In melanoma, however, the p53 gene is intact in a reported 94% of human cases. Rather than direct mutation, p53 is held inactive through interaction with inhibitory proteins. Here, we examine the expression of the two primary inhibitors of p53, MDM2 and MDM4, in genomic databases and biopsy specimens. We find that MDM4 is frequently overexpressed. Moreover, changes in splicing of MDM4 occur frequently and early in melanomagenesis. These changes in splicing must be considered in the design of therapeutic inhibitors of the MDM2/4 proteins for melanoma.
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13
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Birladeanu AM, Rogalska M, Potiri M, Papadaki V, Andreadou M, Kontoyiannis DL, Lewis JD, Erpapazoglou Z, Kafasla P. The scaffold protein IQGAP1 links heat-induced stress signals to alternative splicing regulation in gastric cancer cells. Oncogene 2021; 40:5518-5532. [PMID: 34294847 DOI: 10.1038/s41388-021-01963-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 07/06/2021] [Accepted: 07/13/2021] [Indexed: 02/07/2023]
Abstract
In response to oncogenic signals, Alternative Splicing (AS) regulators such as SR and hnRNP proteins show altered expression levels, subnuclear distribution and/or post-translational modification status, but the link between signals and these changes remains unknown. Here, we report that a cytosolic scaffold protein, IQGAP1, performs this task in response to heat-induced signals. We show that in gastric cancer cells, a nuclear pool of IQGAP1 acts as a tethering module for a group of spliceosome components, including hnRNPM, a splicing factor critical for the response of the spliceosome to heat-shock. IQGAP1 controls hnRNPM's sumoylation, subnuclear localisation and the relevant response of the AS machinery to heat-induced stress. Genome-wide analyses reveal that IQGAP1 and hnRNPM co-regulate the AS of a cell cycle-related RNA regulon in gastric cancer cells, thus favouring the accelerated proliferation phenotype of gastric cancer cells. Overall, we reveal a missing link between stress signals and AS regulation.
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Affiliation(s)
- Andrada-Maria Birladeanu
- Institute for Fundamental Biomedical Research, B.S.R.C. "Alexander Fleming", 34 Fleming st. 16672 Vari, Athens, Greece
| | - Malgorzata Rogalska
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr Aiguader 88, Barcelona, 08003, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, 08003, Spain
| | - Myrto Potiri
- Institute for Fundamental Biomedical Research, B.S.R.C. "Alexander Fleming", 34 Fleming st. 16672 Vari, Athens, Greece
| | - Vasiliki Papadaki
- Institute for Fundamental Biomedical Research, B.S.R.C. "Alexander Fleming", 34 Fleming st. 16672 Vari, Athens, Greece
| | - Margarita Andreadou
- Institute for Fundamental Biomedical Research, B.S.R.C. "Alexander Fleming", 34 Fleming st. 16672 Vari, Athens, Greece
| | - Dimitris L Kontoyiannis
- Institute for Fundamental Biomedical Research, B.S.R.C. "Alexander Fleming", 34 Fleming st. 16672 Vari, Athens, Greece
- Department of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Joe D Lewis
- European Molecular Biology Laboratory, 69117, Heidelberg, Germany
| | - Zoi Erpapazoglou
- Institute for Fundamental Biomedical Research, B.S.R.C. "Alexander Fleming", 34 Fleming st. 16672 Vari, Athens, Greece
| | - Panagiota Kafasla
- Institute for Fundamental Biomedical Research, B.S.R.C. "Alexander Fleming", 34 Fleming st. 16672 Vari, Athens, Greece.
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14
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Coelho AVC, Gratton R, de Melo JPB, Andrade-Santos JL, Guimarães RL, Crovella S, Tricarico PM, Brandão LAC. HIV-1 Infection Transcriptomics: Meta-Analysis of CD4+ T Cells Gene Expression Profiles. Viruses 2021; 13:v13020244. [PMID: 33557210 PMCID: PMC7913929 DOI: 10.3390/v13020244] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/26/2021] [Accepted: 02/01/2021] [Indexed: 12/26/2022] Open
Abstract
HIV-1 infection elicits a complex dynamic of the expression various host genes. High throughput sequencing added an expressive amount of information regarding HIV-1 infections and pathogenesis. RNA sequencing (RNA-Seq) is currently the tool of choice to investigate gene expression in a several range of experimental setting. This study aims at performing a meta-analysis of RNA-Seq expression profiles in samples of HIV-1 infected CD4+ T cells compared to uninfected cells to assess consistently differentially expressed genes in the context of HIV-1 infection. We selected two studies (22 samples: 15 experimentally infected and 7 mock-infected). We found 208 differentially expressed genes in infected cells when compared to uninfected/mock-infected cells. This result had moderate overlap when compared to previous studies of HIV-1 infection transcriptomics, but we identified 64 genes already known to interact with HIV-1 according to the HIV-1 Human Interaction Database. A gene ontology (GO) analysis revealed enrichment of several pathways involved in immune response, cell adhesion, cell migration, inflammation, apoptosis, Wnt, Notch and ERK/MAPK signaling.
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Affiliation(s)
- Antonio Victor Campos Coelho
- Department of Pathology, Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235 Cidade Universitária, Recife 50670-901, Brazil; (J.P.B.d.M.); (L.A.C.B.)
- Correspondence: ; Tel.: +55-81-2126-8522
| | - Rossella Gratton
- Department of Advanced Translational Microbiology, Institute for Maternal and Child Health IRCCS Burlo Garofolo, Via dell’Istria 65/1, 34137 Trieste, Italy; (R.G.); (P.M.T.)
| | - João Paulo Britto de Melo
- Department of Pathology, Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235 Cidade Universitária, Recife 50670-901, Brazil; (J.P.B.d.M.); (L.A.C.B.)
| | - José Leandro Andrade-Santos
- Department of Genetics-Federal, University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235 Cidade Universitária, Recife 50670-901, Brazil; (J.L.A.-S.); (R.L.G.)
- Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235 Cidade Universitária, Recife 50670-901, Brazil
| | - Rafael Lima Guimarães
- Department of Genetics-Federal, University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235 Cidade Universitária, Recife 50670-901, Brazil; (J.L.A.-S.); (R.L.G.)
- Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235 Cidade Universitária, Recife 50670-901, Brazil
| | - Sergio Crovella
- Department of Biological and Environmental Sciences, College of Arts and Sciences, University of Qatar, Doha P.O. Box 2713, Qatar;
| | - Paola Maura Tricarico
- Department of Advanced Translational Microbiology, Institute for Maternal and Child Health IRCCS Burlo Garofolo, Via dell’Istria 65/1, 34137 Trieste, Italy; (R.G.); (P.M.T.)
| | - Lucas André Cavalcanti Brandão
- Department of Pathology, Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235 Cidade Universitária, Recife 50670-901, Brazil; (J.P.B.d.M.); (L.A.C.B.)
- Department of Advanced Translational Microbiology, Institute for Maternal and Child Health IRCCS Burlo Garofolo, Via dell’Istria 65/1, 34137 Trieste, Italy; (R.G.); (P.M.T.)
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15
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Panzeri V, Manni I, Capone A, Naro C, Sacconi A, Di Agostino S, de Latouliere L, Montori A, Pilozzi E, Piaggio G, Capurso G, Sette C. The RNA-binding protein MEX3A is a prognostic factor and regulator of resistance to gemcitabine in pancreatic ductal adenocarcinoma. Mol Oncol 2020; 15:579-595. [PMID: 33159833 PMCID: PMC7858117 DOI: 10.1002/1878-0261.12847] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 10/16/2020] [Accepted: 11/05/2020] [Indexed: 12/16/2022] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer. Most patients present with advanced disease at diagnosis, which only permits palliative chemotherapeutic treatments. RNA dysregulation is a hallmark of most human cancers, including PDAC. To test the impact of RNA processing dysregulation on PDAC pathology, we performed a bioinformatics analysis to identify RNA-binding proteins (RBPs) associated with prognosis. Among the 12 RBPs associated with progression-free survival, we focused on MEX3A because it was recently shown to mark an intestinal stem cell population that is refractory to chemotherapeutic treatments, a typical feature of PDAC. Increased expression of MEX3A was correlated with higher disease stage in PDAC patients and with tumor development in a mouse model of PDAC. Depletion of MEX3A in PDAC cells enhanced sensitivity to chemotherapeutic treatment with gemcitabine, whereas its expression was increased in PDAC cells selected upon chronic exposure to the drug. RNA-sequencing analyses highlighted hundreds of genes whose expression is sensitive to MEX3A expression, with significant enrichment in cell cycle genes. MEX3A binds to its target mRNAs, like cyclin-dependent kinase 6 (CDK6), and promotes their stability. Accordingly, knockdown of MEX3A caused a significant reduction in PDAC cell proliferation and in progression to the S phase of the cell cycle. These findings uncover a novel role for MEX3A in the acquisition and maintenance of chemoresistance by PDAC cells, suggesting that it may represent a novel therapeutic target for PDAC.
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Affiliation(s)
- Valentina Panzeri
- Department of Science Medical/Chirurgic and Translational Medicine, University of Rome "Sapienza", Italy.,Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy
| | - Isabella Manni
- UOSD SAFU, Department of Research, Diagnosis and Innovative Technologies, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | | | - Chiara Naro
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy.,IRCCS Fondazione Policlinico Agostino Gemelli, Rome, Italy
| | - Andrea Sacconi
- Clinical Trial Center, Biostatistics and Bioinformatics Unit, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Silvia Di Agostino
- Oncogenomic and Epigenetic Unit, Department of Diagnostic Research and Technological Innovation, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Luisa de Latouliere
- UOSD SAFU, Department of Research, Diagnosis and Innovative Technologies, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Andrea Montori
- Department of Clinical and Molecular Medicine, UOC Anatomia Patologica, Sant' Andrea Hospital, Sapienza University of Rome, Italy
| | - Emanuela Pilozzi
- Department of Clinical and Molecular Medicine, UOC Anatomia Patologica, Sant' Andrea Hospital, Sapienza University of Rome, Italy
| | - Giulia Piaggio
- UOSD SAFU, Department of Research, Diagnosis and Innovative Technologies, IRCCS Regina Elena National Cancer Institute, Rome, Italy
| | - Gabriele Capurso
- PancreatoBiliary Endoscopy and EUS Division, Pancreas Translational and Clinical Research Center, San Raffaele Scientific Institute IRCCS, Milan, Italy
| | - Claudio Sette
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy.,Fondazione Santa Lucia IRCCS, Rome, Italy
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16
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Baeza-Centurion P, Miñana B, Valcárcel J, Lehner B. Mutations primarily alter the inclusion of alternatively spliced exons. eLife 2020; 9:59959. [PMID: 33112234 PMCID: PMC7673789 DOI: 10.7554/elife.59959] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/27/2020] [Indexed: 12/17/2022] Open
Abstract
Genetic analyses and systematic mutagenesis have revealed that synonymous, non-synonymous and intronic mutations frequently alter the inclusion levels of alternatively spliced exons, consistent with the concept that altered splicing might be a common mechanism by which mutations cause disease. However, most exons expressed in any cell are highly-included in mature mRNAs. Here, by performing deep mutagenesis of highly-included exons and by analysing the association between genome sequence variation and exon inclusion across the transcriptome, we report that mutations only very rarely alter the inclusion of highly-included exons. This is true for both exonic and intronic mutations as well as for perturbations in trans. Therefore, mutations that affect splicing are not evenly distributed across primary transcripts but are focussed in and around alternatively spliced exons with intermediate inclusion levels. These results provide a resource for prioritising synonymous and other variants as disease-causing mutations.
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Affiliation(s)
- Pablo Baeza-Centurion
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Belén Miñana
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Juan Valcárcel
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Ben Lehner
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
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17
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Monteuuis G, Wong JJL, Bailey CG, Schmitz U, Rasko JEJ. The changing paradigm of intron retention: regulation, ramifications and recipes. Nucleic Acids Res 2020; 47:11497-11513. [PMID: 31724706 PMCID: PMC7145568 DOI: 10.1093/nar/gkz1068] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 10/04/2019] [Accepted: 10/30/2019] [Indexed: 12/13/2022] Open
Abstract
Intron retention (IR) is a form of alternative splicing that has long been neglected in mammalian systems although it has been studied for decades in non-mammalian species such as plants, fungi, insects and viruses. It was generally assumed that mis-splicing, leading to the retention of introns, would have no physiological consequence other than reducing gene expression by nonsense-mediated decay. Relatively recent landmark discoveries have highlighted the pivotal role that IR serves in normal and disease-related human biology. Significant technical hurdles have been overcome, thereby enabling the robust detection and quantification of IR. Still, relatively little is known about the cis- and trans-acting modulators controlling this phenomenon. The fate of an intron to be, or not to be, retained in the mature transcript is the direct result of the influence exerted by numerous intrinsic and extrinsic factors at multiple levels of regulation. These factors have altered current biological paradigms and provided unexpected insights into the transcriptional landscape. In this review, we discuss the regulators of IR and methods to identify them. Our focus is primarily on mammals, however, we broaden the scope to non-mammalian organisms in which IR has been shown to be biologically relevant.
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Affiliation(s)
- Geoffray Monteuuis
- Gene and Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, Australia
| | - Justin J L Wong
- Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia.,Epigenetics and RNA Biology Program Centenary Institute, The University of Sydney, Camperdown, Australia
| | - Charles G Bailey
- Gene and Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, Australia.,Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia
| | - Ulf Schmitz
- Gene and Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, Australia.,Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia.,Computational Biomedicine Laboratory Centenary Institute, The University of Sydney, Camperdown, Australia
| | - John E J Rasko
- Gene and Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, Australia.,Faculty of Medicine and Health, The University of Sydney, NSW 2006, Australia.,Cell and Molecular Therapies, Royal Prince Alfred Hospital, Camperdown, Australia
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18
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Mukund K, Syulyukina N, Ramamoorthy S, Subramaniam S. Right and left-sided colon cancers - specificity of molecular mechanisms in tumorigenesis and progression. BMC Cancer 2020; 20:317. [PMID: 32293332 PMCID: PMC7161305 DOI: 10.1186/s12885-020-06784-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 03/24/2020] [Indexed: 12/13/2022] Open
Abstract
Background Given the differences in embryonic origin, vascular and nervous supplies, microbiotic burden, and main physiological functions of left and right colons, tumor location is increasingly suggested to dictate tumor behavior affecting pathology, progression and prognosis. Right-sided colon cancers arise in the cecum, ascending colon, hepatic flexure and/or transverse colon, while left-sided colon cancers arise in the splenic flexure, descending, and/or sigmoid colon. In contrast to prior reports, we attempt to delineate programs of tumorigenesis independently for each side. Methods Four hundred and eleven samples were extracted from The Cancer Genome Atlas-COAD cohort, based on a conservative sample inclusion criterion. Each side was independently analyzed with respect to their respective normal tissue, at the level of transcription, post-transcription, miRNA control and methylation in both a stage specific and stage-agnostic manner. Results Our results indicate a suppression of enzymes involved in various stages of carcinogen breakdown including CYP2C8, CYP4F12, GSTA1, and UGT1A within right colon tumors. This implies its reduced capacity to detoxify carcinogens, contributing to a genotoxic tumor environment, and subsequently a more aggressive phenotype. Additionally, we highlight a crucial nexus between calcium homeostasis (sensing, mobilization and absorption) and immune/GPCR signaling within left-sided tumors, possibly contributing to its reduced proliferative and metastatic potential. Interestingly, two genes SLC6A4 and HOXB13 show opposing regulatory trends within right and left tumors. Post-transcriptional regulation mediated by both RNA-binding proteins (e.g. NKRF (in left) and MSI2 (in right)) and miRNAs (e.g. miR-29a (in left); miR-155, miR181-d, miR-576 and miR23a (in right)) appear to exhibit side-specificity in control of their target transcripts and is pronounced in right colon tumors. Additionally, methylation results depict location-specific differences, with increased hypomethylation in open seas within left tumors, and increased hypermethylation of CpG islands within right tumors. Conclusions Differences in molecular mechanisms captured here highlight distinctions in tumorigenesis and progression between left and right colon tumors, which will serve as the basis for future studies, influencing the efficacies of existing and future diagnostic, prognostic and therapeutic interventions.
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Affiliation(s)
- Kavitha Mukund
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
| | - Natalia Syulyukina
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
| | - Sonia Ramamoorthy
- Division of Colon and Rectal Surgery, Moores Cancer Center, University of California San Diego Health System, La Jolla, CA, USA
| | - Shankar Subramaniam
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA. .,Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA. .,Department of Computer Science and Engineering, University of California, San Diego, La Jolla, CA, USA.
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ASCOT identifies key regulators of neuronal subtype-specific splicing. Nat Commun 2020; 11:137. [PMID: 31919425 PMCID: PMC6952364 DOI: 10.1038/s41467-019-14020-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 12/12/2019] [Indexed: 12/22/2022] Open
Abstract
Public archives of next-generation sequencing data are growing exponentially, but the difficulty of marshaling this data has led to its underutilization by scientists. Here, we present ASCOT, a resource that uses annotation-free methods to rapidly analyze and visualize splice variants across tens of thousands of bulk and single-cell data sets in the public archive. To demonstrate the utility of ASCOT, we identify novel cell type-specific alternative exons across the nervous system and leverage ENCODE and GTEx data sets to study the unique splicing of photoreceptors. We find that PTBP1 knockdown and MSI1 and PCBP2 overexpression are sufficient to activate many photoreceptor-specific exons in HepG2 liver cancer cells. This work demonstrates how large-scale analysis of public RNA-Seq data sets can yield key insights into cell type-specific control of RNA splicing and underscores the importance of considering both annotated and unannotated splicing events.
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A stroma-corrected ZEB1 transcriptional signature is inversely associated with antitumor immune activity in breast cancer. Sci Rep 2019; 9:17807. [PMID: 31780722 PMCID: PMC6882801 DOI: 10.1038/s41598-019-54282-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 11/06/2019] [Indexed: 12/13/2022] Open
Abstract
The epithelial-to-mesenchymal transition (EMT) is an essential developmental process which can be hijacked by cancer cells, leading to enhanced metastasis and chemoresistance in experimental models. Recent studies have linked gene expression of EMT-associated gene signatures to increased inflammatory immune response in multiple cancer types. However, these studies did not account for the potential confounding effects of gene expression by tumor-infiltrating mesenchymal stromal cells. In this study, we comprehensively dissect the associations between multiple EMT transcription factors and EMT markers with stromal and immune tumor infiltration. We find that EMT-related genes are highly correlated with intratumoral stromal cell abundance and identify a specific relationship between stroma-corrected ZEB1 expression and decreased immune activity in multiple cancer types. We derive a stroma-corrected ZEB1-activated transcriptional signature and demonstrate that this signature includes several known inhibitors of inflammation, including BMPR2. Finally, multivariate survival analysis reveals that ZEB1 and its expression signature are significantly associated with reduced overall survival in breast cancer patients. In conclusion, this study identifies a novel association between stroma-adjusted ZEB1 expression and tumor immune activity and addresses the critical issue of confounding between EMT-associated genes and tumor stromal content.
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Coomer AO, Black F, Greystoke A, Munkley J, Elliott DJ. Alternative splicing in lung cancer. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194388. [PMID: 31152916 DOI: 10.1016/j.bbagrm.2019.05.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 05/20/2019] [Indexed: 12/21/2022]
Abstract
Lung cancer has the highest mortality rate of all cancers worldwide. Lung cancer is a very heterogeneous disease that is often diagnosed at later stages which have a poor prognosis. Aberrant alternative splicing patterns found in lung cancer contribute to important cell functions. These include changes in splicing for the BCL2L1, MDM2, MDM4, NUMB and MET genes during lung tumourigenesis, to affect pathways involved in apoptosis, cell proliferation and cellular cohesion. Global analyses of RNASeq datasets suggest there may be many more potentially influential aberrant splicing events that need to be investigated in lung cancer. Changes in expression of the splicing factors that regulate alternative splicing events have also been identified in lung cancer. Of these, changes in expression of QKI, RBM4, RBM5, RBM6, RBM10 and SRSF1 proteins regulate many of the most frequently referenced aberrant splicing events in lung cancer. The expanding list of genes known to be aberrantly spliced in lung cancer along with the altered expression of splicing factors that regulate them are providing new clues as to how lung cancer develops, and how these events can be exploited for better treatment. This article is part of a Special Issue entitled: RNA structure and splicing regulation edited by Francisco Baralle, Ravindra Singh and Stefan Stamm.
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Affiliation(s)
- Alice O Coomer
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, United Kingdom of Great Britain and Northern Ireland.
| | - Fiona Black
- Cellular Pathology Department, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP, United Kingdom of Great Britain and Northern Ireland
| | - Alastair Greystoke
- Northern Institute for Cancer Research, Paul O'Gorman Building, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom of Great Britain and Northern Ireland
| | - Jennifer Munkley
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, United Kingdom of Great Britain and Northern Ireland
| | - David J Elliott
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, United Kingdom of Great Britain and Northern Ireland.
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Munkley J, Li L, Krishnan SRG, Hysenaj G, Scott E, Dalgliesh C, Oo HZ, Maia TM, Cheung K, Ehrmann I, Livermore KE, Zielinska H, Thompson O, Knight B, McCullagh P, McGrath J, Crundwell M, Harries LW, Daugaard M, Cockell S, Barbosa-Morais NL, Oltean S, Elliott DJ. Androgen-regulated transcription of ESRP2 drives alternative splicing patterns in prostate cancer. eLife 2019; 8:47678. [PMID: 31478829 PMCID: PMC6788855 DOI: 10.7554/elife.47678] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 09/02/2019] [Indexed: 12/14/2022] Open
Abstract
Prostate is the most frequent cancer in men. Prostate cancer progression is driven by androgen steroid hormones, and delayed by androgen deprivation therapy (ADT). Androgens control transcription by stimulating androgen receptor (AR) activity, yet also control pre-mRNA splicing through less clear mechanisms. Here we find androgens regulate splicing through AR-mediated transcriptional control of the epithelial-specific splicing regulator ESRP2. Both ESRP2 and its close paralog ESRP1 are highly expressed in primary prostate cancer. Androgen stimulation induces splicing switches in many endogenous ESRP2-controlled mRNA isoforms, including splicing switches correlating with disease progression. ESRP2 expression in clinical prostate cancer is repressed by ADT, which may thus inadvertently dampen epithelial splice programmes. Supporting this, treatment with the AR antagonist bicalutamide (Casodex) induced mesenchymal splicing patterns of genes including FLNB and CTNND1. Our data reveals a new mechanism of splicing control in prostate cancer with important implications for disease progression.
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Affiliation(s)
- Jennifer Munkley
- Institute of Genetic MedicineUniversity of NewcastleNewcastleUnited Kingdom
| | - Ling Li
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and HealthUniversity of ExeterExeterUnited Kingdom
| | - S R Gokul Krishnan
- Institute of Genetic MedicineUniversity of NewcastleNewcastleUnited Kingdom
| | - Gerald Hysenaj
- Institute of Genetic MedicineUniversity of NewcastleNewcastleUnited Kingdom
| | - Emma Scott
- Institute of Genetic MedicineUniversity of NewcastleNewcastleUnited Kingdom
| | - Caroline Dalgliesh
- Institute of Genetic MedicineUniversity of NewcastleNewcastleUnited Kingdom
| | - Htoo Zarni Oo
- Department of Urologic SciencesUniversity of British ColumbiaVancouverCanada,Vancouver Prostate CentreVancouverCanada
| | - Teresa Mendes Maia
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de MedicinaUniversidade de LisboaLisboaPortugal,VIB Center for Medical BiotechnologyVIBGhentBelgium,VIB Proteomics CoreVIBGhentBelgium,Department for Biomolecular MedicineGhent UniversityGhentBelgium
| | - Kathleen Cheung
- Bioinformatics Support Unit, Faculty of Medical SciencesNewcastle UniversityNewcastleUnited Kingdom
| | - Ingrid Ehrmann
- Institute of Genetic MedicineUniversity of NewcastleNewcastleUnited Kingdom
| | - Karen E Livermore
- Institute of Genetic MedicineUniversity of NewcastleNewcastleUnited Kingdom
| | - Hanna Zielinska
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and HealthUniversity of ExeterExeterUnited Kingdom
| | - Oliver Thompson
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and HealthUniversity of ExeterExeterUnited Kingdom
| | - Bridget Knight
- NIHR Exeter Clinical Research FacilityRoyal Devon and Exeter NHS Foundation TrustExeterUnited Kingdom
| | - Paul McCullagh
- Department of PathologyRoyal Devon and Exeter NHS Foundation TrustExeterUnited Kingdom
| | - John McGrath
- Exeter Surgical Health Services Research UnitRoyal Devon and Exeter NHS Foundation TrustExeterUnited Kingdom
| | - Malcolm Crundwell
- Department of UrologyRoyal Devon and Exeter NHS Foundation TrustExeterUnited Kingdom
| | - Lorna W Harries
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and HealthUniversity of ExeterExeterUnited Kingdom
| | - Mads Daugaard
- Department of Urologic SciencesUniversity of British ColumbiaVancouverCanada,Vancouver Prostate CentreVancouverCanada
| | - Simon Cockell
- Bioinformatics Support Unit, Faculty of Medical SciencesNewcastle UniversityNewcastleUnited Kingdom
| | - Nuno L Barbosa-Morais
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de MedicinaUniversidade de LisboaLisboaPortugal
| | - Sebastian Oltean
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and HealthUniversity of ExeterExeterUnited Kingdom
| | - David J Elliott
- Institute of Genetic MedicineUniversity of NewcastleNewcastleUnited Kingdom
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