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Shi X, Facemire L, Singh S, Kumar S, Cornelison R, Liang C, Qin F, Liu A, Lin S, Tang Y, Elfman J, Manley T, Bullock T, Haverstick DM, Wu P, Li H. UBA1-CDK16 : A Sex-Specific Chimeric RNA and Its Role in Immune Sexual Dimorphism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.13.580120. [PMID: 38405903 PMCID: PMC10888732 DOI: 10.1101/2024.02.13.580120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
RNA processing mechanisms, such as alternative splicing and RNA editing, have been recognized as critical means to expand the transcriptome. Chimeric RNAs formed by intergenic splicing provide another potential layer of RNA diversification. By analyzing a large set of RNA-Seq data and validating results in over 1,200 blood samples, we identified UBA1-CDK16 , a female-specific chimeric transcript. Intriguingly, both parental genes, are expressed in males and females. Mechanistically, UBA1-CDK16 is produced by cis-splicing between the two adjacent X-linked genes, originating from the inactive X chromosome. A female-specific chromatin loop, formed between the junction sites, facilitates the alternative splicing of its readthrough precursor. This unique chimeric transcript exhibits evolutionary conservation, evolving to be female-specific from non-human primates to humans. Furthermore, our investigation reveals that UBA1-CDK16 is enriched in the myeloid lineage and plays a regulatory role in myeloid differentiation. Notably, female COVID-19 patients who tested negative for this chimeric transcript displayed higher counts of neutrophils, highlighting its potential role in disease pathogenesis. These findings support the notion that chimeric RNAs represent a new repertoire of transcripts that can be regulated independently from the parental genes, and a new class of RNA variance with potential implications in sexual dimorphism and immune responses.
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2
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Arshadi A, Tolomeo D, Venuto S, Storlazzi CT. Advancements in Focal Amplification Detection in Tumor/Liquid Biopsies and Emerging Clinical Applications. Genes (Basel) 2023; 14:1304. [PMID: 37372484 PMCID: PMC10298061 DOI: 10.3390/genes14061304] [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: 05/17/2023] [Revised: 06/14/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
Focal amplifications (FAs) are crucial in cancer research due to their significant diagnostic, prognostic, and therapeutic implications. FAs manifest in various forms, such as episomes, double minute chromosomes, and homogeneously staining regions, arising through different mechanisms and mainly contributing to cancer cell heterogeneity, the leading cause of drug resistance in therapy. Numerous wet-lab, mainly FISH, PCR-based assays, next-generation sequencing, and bioinformatics approaches have been set up to detect FAs, unravel the internal structure of amplicons, assess their chromatin compaction status, and investigate the transcriptional landscape associated with their occurrence in cancer cells. Most of them are tailored for tumor samples, even at the single-cell level. Conversely, very limited approaches have been set up to detect FAs in liquid biopsies. This evidence suggests the need to improve these non-invasive investigations for early tumor detection, monitoring disease progression, and evaluating treatment response. Despite the potential therapeutic implications of FAs, such as, for example, the use of HER2-specific compounds for patients with ERBB2 amplification, challenges remain, including developing selective and effective FA-targeting agents and understanding the molecular mechanisms underlying FA maintenance and replication. This review details a state-of-the-art of FA investigation, with a particular focus on liquid biopsies and single-cell approaches in tumor samples, emphasizing their potential to revolutionize the future diagnosis, prognosis, and treatment of cancer patients.
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Affiliation(s)
| | | | | | - Clelia Tiziana Storlazzi
- Department of Biosciences, Biotechnology and Environment, University of Bari Aldo Moro, 70125 Bari, Italy; (A.A.); (D.T.); (S.V.)
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3
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Sun Y, Li H. Chimeric RNAs Discovered by RNA Sequencing and Their Roles in Cancer and Rare Genetic Diseases. Genes (Basel) 2022; 13:741. [PMID: 35627126 PMCID: PMC9140685 DOI: 10.3390/genes13050741] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/13/2022] [Accepted: 04/20/2022] [Indexed: 12/30/2022] Open
Abstract
Chimeric RNAs are transcripts that are generated by gene fusion and intergenic splicing events, thus comprising nucleotide sequences from different parental genes. In the past, Northern blot analysis and RT-PCR were used to detect chimeric RNAs. However, they are low-throughput and can be time-consuming, labor-intensive, and cost-prohibitive. With the development of RNA-seq and transcriptome analyses over the past decade, the number of chimeric RNAs in cancer as well as in rare inherited diseases has dramatically increased. Chimeric RNAs may be potential diagnostic biomarkers when they are specifically expressed in cancerous cells and/or tissues. Some chimeric RNAs can also play a role in cell proliferation and cancer development, acting as tools for cancer prognosis, and revealing new insights into the cell origin of tumors. Due to their abilities to characterize a whole transcriptome with a high sequencing depth and intergenically identify spliced chimeric RNAs produced with the absence of chromosomal rearrangement, RNA sequencing has not only enhanced our ability to diagnose genetic diseases, but also provided us with a deeper understanding of these diseases. Here, we reviewed the mechanisms of chimeric RNA formation and the utility of RNA sequencing for discovering chimeric RNAs in several types of cancer and rare inherited diseases. We also discussed the diagnostic, prognostic, and therapeutic values of chimeric RNAs.
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Affiliation(s)
- Yunan Sun
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA;
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Hui Li
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA;
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
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4
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Gupta SK, Jea JDY, Yen L. RNA-driven JAZF1-SUZ12 gene fusion in human endometrial stromal cells. PLoS Genet 2021; 17:e1009985. [PMID: 34928964 PMCID: PMC8722726 DOI: 10.1371/journal.pgen.1009985] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 01/03/2022] [Accepted: 12/08/2021] [Indexed: 12/17/2022] Open
Abstract
Oncogenic fusion genes as the result of chromosomal rearrangements are important for understanding genome instability in cancer cells and developing useful cancer therapies. To date, the mechanisms that create such oncogenic fusion genes are poorly understood. Previously we reported an unappreciated RNA-driven mechanism in human prostate cells in which the expression of chimeric RNA induces specified gene fusions in a sequence-dependent manner. One fundamental question yet to be addressed is whether such RNA-driven gene fusion mechanism is generalizable, or rather, a special case restricted to prostate cells. In this report, we demonstrated that the expression of designed chimeric RNAs in human endometrial stromal cells leads to the formation of JAZF1-SUZ12, a cancer fusion gene commonly found in low-grade endometrial stromal sarcomas. The process is specified by the sequence of chimeric RNA involved and inhibited by estrogen or progesterone. Furthermore, it is the antisense rather than sense chimeric RNAs that effectively drive JAZF1-SUZ12 gene fusion. The induced fusion gene is validated both at the RNA and the genomic DNA level. The ability of designed chimeric RNAs to drive and recapitulate the formation of JAZF1-SUZ12 gene fusion in endometrial cells represents another independent case of RNA-driven gene fusion, suggesting that RNA-driven genomic recombination is a permissible mechanism in mammalian cells. The results could have fundamental implications in the role of RNA in genome stability, and provide important insight in early disease mechanisms related to the formation of cancer fusion genes. Fusion genes resulting from chromosomal translocations are important for understanding cancer mechanisms and developing anti-cancer therapies. Fusion gene are presumed to occur prior to fusion RNA expression. However, studies have reported the presence of fusion RNAs in individuals who were negative for chromosomal translocations. The observation, that fusion RNA could be present prior to fusion gene formation, raises the provocative hypothesis that fusion RNA, or any cellular RNA with sequence compositions resembling that of fusion RNA, could act as a template to mediate genomic rearrangement which leads to the final gene fusion. In this report, we demonstrated that the expression of designed chimeric RNAs in human endometrial stromal cells leads to the formation of JAZF1-SUZ12, a cancer fusion gene found in endometrial stromal sarcomas. The process is specified by the sequence of chimeric RNA involved and inhibited by estrogen or progesterone. Furthermore, it is the antisense rather than sense chimeric RNAs that effectively drive JAZF1-SUZ12 gene fusion. The results could have fundamental implications in the role of RNA in mammalian genome stability, provide important insight in early disease mechanism, as well as developing gene editing technology via mechanisms native to mammalian cells.
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Affiliation(s)
- Sachin Kumar Gupta
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas, United States of America
| | - Jocelyn Duen-Ya Jea
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas, United States of America
| | - Laising Yen
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
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5
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Creason A, Haan D, Dang K, Chiotti KE, Inkman M, Lamb A, Yu T, Hu Y, Norman TC, Buchanan A, van Baren MJ, Spangler R, Rollins MR, Spellman PT, Rozanov D, Zhang J, Maher CA, Caloian C, Watson JD, Uhrig S, Haas BJ, Jain M, Akeson M, Ahsen ME, Stolovitzky G, Guinney J, Boutros PC, Stuart JM, Ellrott K. A community challenge to evaluate RNA-seq, fusion detection, and isoform quantification methods for cancer discovery. Cell Syst 2021; 12:827-838.e5. [PMID: 34146471 PMCID: PMC8376800 DOI: 10.1016/j.cels.2021.05.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 09/15/2020] [Accepted: 05/25/2021] [Indexed: 02/03/2023]
Abstract
The accurate identification and quantitation of RNA isoforms present in the cancer transcriptome is key for analyses ranging from the inference of the impacts of somatic variants to pathway analysis to biomarker development and subtype discovery. The ICGC-TCGA DREAM Somatic Mutation Calling in RNA (SMC-RNA) challenge was a crowd-sourced effort to benchmark methods for RNA isoform quantification and fusion detection from bulk cancer RNA sequencing (RNA-seq) data. It concluded in 2018 with a comparison of 77 fusion detection entries and 65 isoform quantification entries on 51 synthetic tumors and 32 cell lines with spiked-in fusion constructs. We report the entries used to build this benchmark, the leaderboard results, and the experimental features associated with the accurate prediction of RNA species. This challenge required submissions to be in the form of containerized workflows, meaning each of the entries described is easily reusable through CWL and Docker containers at https://github.com/SMC-RNA-challenge. A record of this paper's transparent peer review process is included in the supplemental information.
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Affiliation(s)
- Allison Creason
- Biomedical Engineering, Oregon Health and Science University, Portland, OR 97239, USA
| | - David Haan
- Biomolecular Engineering and UC Santa Cruz Genome Institute, University of California, Santa Cruz, Santa Cruz, CA, USA
| | | | - Kami E Chiotti
- Biomedical Engineering, Oregon Health and Science University, Portland, OR 97239, USA
| | - Matthew Inkman
- The Genome Institute, Washington University School of Medicine, 4444 Forest Park Avenue, St. Louis, MO 63110, USA
| | | | | | - Yin Hu
- Sage Bionetworks, Seattle, WA, USA
| | | | - Alex Buchanan
- Biomedical Engineering, Oregon Health and Science University, Portland, OR 97239, USA
| | - Marijke J van Baren
- Biomolecular Engineering and UC Santa Cruz Genome Institute, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Ryan Spangler
- Biomedical Engineering, Oregon Health and Science University, Portland, OR 97239, USA
| | - M Rick Rollins
- Biomedical Engineering, Oregon Health and Science University, Portland, OR 97239, USA
| | - Paul T Spellman
- Biomedical Engineering, Oregon Health and Science University, Portland, OR 97239, USA
| | - Dmitri Rozanov
- Biomedical Engineering, Oregon Health and Science University, Portland, OR 97239, USA
| | - Jin Zhang
- The Genome Institute, Washington University School of Medicine, 4444 Forest Park Avenue, St. Louis, MO 63110, USA
| | - Christopher A Maher
- The Genome Institute, Washington University School of Medicine, 4444 Forest Park Avenue, St. Louis, MO 63110, USA
| | - Cristian Caloian
- Computational Biology, Ontario Institute for Cancer Research, Toronto, Canada
| | - John D Watson
- Computational Biology, Ontario Institute for Cancer Research, Toronto, Canada
| | - Sebastian Uhrig
- Division of Applied Bioinformatics, German Cancer Research Center (DKFZ) and Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Brian J Haas
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Miten Jain
- Biomolecular Engineering and UC Santa Cruz Genome Institute, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Mark Akeson
- Biomolecular Engineering and UC Santa Cruz Genome Institute, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Mehmet Eren Ahsen
- Icahn School of Medicine at Mount Sinai, Department of Genetics and Genomic Sciences, One Gustave Levy Place, New York, NY 1498, USA
| | - Gustavo Stolovitzky
- Icahn School of Medicine at Mount Sinai, Department of Genetics and Genomic Sciences, One Gustave Levy Place, New York, NY 1498, USA; IBM T.J. Watson Research Center, 1101 Kitchawan Road, Route 134, Yorktown Heights, NY 10598, USA
| | | | - Paul C Boutros
- Computational Biology, Ontario Institute for Cancer Research, Toronto, Canada; Departments of Medical Biophysics and Pharmacology & Toxicology, University of Toronto, Toronto, Canada; Departments of Human Genetics and Urology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Joshua M Stuart
- Biomolecular Engineering and UC Santa Cruz Genome Institute, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Kyle Ellrott
- Biomedical Engineering, Oregon Health and Science University, Portland, OR 97239, USA.
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6
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Gillani R, Seong BKA, Crowdis J, Conway JR, Dharia NV, Alimohamed S, Haas BJ, Han K, Park J, Dietlein F, He MX, Imamovic A, Ma C, Bassik MC, Boehm JS, Vazquez F, Gusev A, Liu D, Janeway KA, McFarland JM, Stegmaier K, Van Allen EM. Gene Fusions Create Partner and Collateral Dependencies Essential to Cancer Cell Survival. Cancer Res 2021; 81:3971-3984. [PMID: 34099491 PMCID: PMC8338889 DOI: 10.1158/0008-5472.can-21-0791] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 03/26/2021] [Accepted: 06/04/2021] [Indexed: 01/07/2023]
Abstract
Gene fusions frequently result from rearrangements in cancer genomes. In many instances, gene fusions play an important role in oncogenesis; in other instances, they are thought to be passenger events. Although regulatory element rearrangements and copy number alterations resulting from these structural variants are known to lead to transcriptional dysregulation across cancers, the extent to which these events result in functional dependencies with an impact on cancer cell survival is variable. Here we used CRISPR-Cas9 dependency screens to evaluate the fitness impact of 3,277 fusions across 645 cell lines from the Cancer Dependency Map. We found that 35% of cell lines harbored either a fusion partner dependency or a collateral dependency on a gene within the same topologically associating domain as a fusion partner. Fusion-associated dependencies revealed numerous novel oncogenic drivers and clinically translatable alterations. Broadly, fusions can result in partner and collateral dependencies that have biological and clinical relevance across cancer types. SIGNIFICANCE: This study provides insights into how fusions contribute to fitness in different cancer contexts beyond partner-gene activation events, identifying partner and collateral dependencies that may have direct implications for clinical care.
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Affiliation(s)
- Riaz Gillani
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Broad Institute of Harvard and MIT, Cambridge, Massachusetts.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts.,Boston Children's Hospital, Boston, Massachusetts
| | - Bo Kyung A. Seong
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Broad Institute of Harvard and MIT, Cambridge, Massachusetts
| | - Jett Crowdis
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Jake R. Conway
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - Neekesh V. Dharia
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Broad Institute of Harvard and MIT, Cambridge, Massachusetts.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts.,Boston Children's Hospital, Boston, Massachusetts
| | - Saif Alimohamed
- Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina
| | - Brian J. Haas
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts
| | - Kyuho Han
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Jihye Park
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Felix Dietlein
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Meng Xiao He
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - Alma Imamovic
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Clement Ma
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Michael C. Bassik
- Department of Genetics, Stanford University School of Medicine, Stanford, California.,Program in Cancer Biology, Stanford University School of Medicine, Stanford, California.,Program in Chemistry, Engineering and Medicine for Human Health (ChEM-H), Stanford University, Stanford, California
| | - Jesse S. Boehm
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts
| | | | - Alexander Gusev
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - David Liu
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Katherine A. Janeway
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts.,Boston Children's Hospital, Boston, Massachusetts
| | | | - Kimberly Stegmaier
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Broad Institute of Harvard and MIT, Cambridge, Massachusetts.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts.,Boston Children's Hospital, Boston, Massachusetts
| | - Eliezer M. Van Allen
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.,Center for Cancer Genomics, Dana-Farber Cancer Institute, Boston, Massachusetts.,Corresponding Author: Eliezer M. Van Allen, Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215. Phone: 617-632-6656; E-mail:
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7
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Chu J, Robert F, Pelletier J. Trans-spliced mRNA products produced from circRNA expression vectors. RNA (NEW YORK, N.Y.) 2021; 27:676-682. [PMID: 33762403 PMCID: PMC8127989 DOI: 10.1261/rna.078261.120] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 03/21/2021] [Indexed: 06/12/2023]
Abstract
Circular (circ) RNA expression vectors are used as a method of identifying and characterizing RNA sequences that harbor internal ribosome entry site (IRES) activity. During the course of developing a vector series tailored for IRES discovery, we found evidence for the occurrence of trans-spliced mRNAs arising when sequences with promoter activity were embedded between the upstream CTD and downstream NTD exons of the pre-mRNA. These trans-spliced products regenerate the same open reading frame expected from a circRNA and can lead to false-positive signals in screens relying on circRNA expression vectors for IRES discovery. Our results caution against interpretations of IRES activity solely based on results obtained from circRNA expression vectors.
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Affiliation(s)
- Jennifer Chu
- Department of Biochemistry, McGill University, Montreal, Canada, H3G 1Y6
| | - Francis Robert
- Department of Biochemistry, McGill University, Montreal, Canada, H3G 1Y6
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Canada, H3G 1Y6
- Department of Oncology, McGill University, Montreal, Canada, H3A 1G5
- Rosalind & Morris Goodman Cancer Research Centre, McGill University, Montreal, Canada, H3A 1A3
- Centre de Recherche en Biologie Structurale, McGill University, Montreal, Canada, H3G 1Y6
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8
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Han C, Sun LY, Wang WT, Sun YM, Chen YQ. Non-coding RNAs in cancers with chromosomal rearrangements: the signatures, causes, functions and implications. J Mol Cell Biol 2020; 11:886-898. [PMID: 31361891 PMCID: PMC6884712 DOI: 10.1093/jmcb/mjz080] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 05/24/2019] [Accepted: 05/26/2019] [Indexed: 12/25/2022] Open
Abstract
Chromosomal translocation leads to the juxtaposition of two otherwise separate DNA loci, which could result in gene fusion. These rearrangements at the DNA level are catastrophic events and often have causal roles in tumorigenesis. The oncogenic DNA messages are transferred to RNA molecules, which are in most cases translated into cancerous fusion proteins. Gene expression programs and signaling pathways are altered in these cytogenetically abnormal contexts. Notably, non-coding RNAs have attracted increasing attention and are believed to be tightly associated with chromosome-rearranged cancers. These RNAs not only function as modulators in downstream pathways but also directly affect chromosomal translocation or the associated products. This review summarizes recent research advances on the relationship between non-coding RNAs and chromosomal translocations and on diverse functions of non-coding RNAs in cancers with chromosomal rearrangements.
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Affiliation(s)
- Cai Han
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, China
| | - Lin-Yu Sun
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, China
| | - Wen-Tao Wang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, China
| | - Yu-Meng Sun
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, China
| | - Yue-Qin Chen
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, China
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9
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Abstract
Chimeric RNAs are hybrid transcripts containing exons from two separate genes. Chimeric RNAs are traditionally considered to be transcribed from fusion genes caused by chromosomal rearrangement. These canonical chimeric RNAs are well characterized to be expressed in a cancer-unique pattern and/or act as oncogene products. However, benefited by the development of advanced deep sequencing technologies, novel types of non-canonical chimeric RNAs have been discovered to be generated from intergenic splicing without genomic aberrations. They can be formed through trans-splicing or cis-splicing between adjacent genes (cis-SAGe) mechanisms. Non-canonical chimeric RNAs are widely detected in normal physiology, although several have been shown to have a cancer-specific expression pattern. Further studies have indicated that some of them play fundamental roles in controlling cell growth and motility, and may have functions independent of the parental genes. These discoveries are unveiling a new layer of the functional transcriptome and are also raising the possibility of utilizing non-canonical chimeric RNAs as cancer diagnostic markers and therapeutic targets. In this chapter, we will overview different categories of chimeric RNAs and their expression in various types of cancerous and normal samples. Acknowledging that chimeric RNAs are not unique to cancer, we will discuss both bioinformatic and biological methods to identify credible cancer-specific chimeric RNAs. Furthermore, we will describe downstream methods to explore their molecular processing mechanisms and potential functions. A better understanding of the biogenesis mechanisms and functional products of cancer-specific chimeric RNAs will pave ways for the development of novel cancer biomarkers and therapeutic targets.
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Affiliation(s)
- Xinrui Shi
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Sandeep Singh
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Emily Lin
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Hui Li
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Charlottesville, VA, United States; Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA, United States.
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10
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Tsai FJ, Lai MT, Cheng J, Chao SCC, Korla PK, Chen HJ, Lin CM, Tsai MH, Hua CH, Jan CI, Jinawath N, Wu CC, Chen CM, Kuo BYT, Chen LW, Yang J, Hwang T, Sheu JJC. Novel K6-K14 keratin fusion enhances cancer stemness and aggressiveness in oral squamous cell carcinoma. Oncogene 2019; 38:5113-5126. [PMID: 30867567 DOI: 10.1038/s41388-019-0781-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 02/15/2019] [Accepted: 02/26/2019] [Indexed: 12/13/2022]
Abstract
Keratin intermediate filament (IF) is one component of cellular architectures, which provides necessary mechanical support to conquer environmental stresses. Recent findings reveal its involvement in mechano-transduction and the associated stem cell reprogramming, suggesting the possible roles in cancer development. Here, we report t(12;17)(q13.13;q21.2) chromosomal rearrangement as the most common fusion event in OSCC, resulting in a variety of inter-keratin fusions. Junction site mapping verified 9 in-frame K6-K14 variants, three of which were correlated with lymph node invasion, late tumor stages (T3/T4) and shorter disease-free survival times. When expressed in OSCC cells, those fusion variants disturbed wild-type K14 organization through direct interaction or aggregate formation, leading to perinuclear structure loss and nuclear deformation. Protein array analyses showed the ability of K6-K14 variant 7 (K6-K14/V7) to upregulate TGF-β and G-CSF signaling, which contributed to cell stemness, drug tolerance, and cell aggressiveness. Notably, K6-K14/V7-expressing cells easily adapted to a soft 3-D culture condition in vitro and formed larger, less differentiated tumors in vivo. In addition to the anti-mechanical-stress activity, our data uncover oncogenic functionality of novel keratin filaments caused by gene fusions during OSCC development.
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Affiliation(s)
- Fuu-Jen Tsai
- Human Genetic Center, China Medical University Hospital, Taichung, 40447, Taiwan.,School of Chinese Medicine, China Medical University, Taichung, 40402, Taiwan
| | - Ming-Tsung Lai
- Department of Pathology, Taichung Hospital, Ministry of Health and Welfare, Taichung, 40343, Taiwan
| | - Jack Cheng
- Human Genetic Center, China Medical University Hospital, Taichung, 40447, Taiwan
| | - Stev Chun-Chin Chao
- Human Genetic Center, China Medical University Hospital, Taichung, 40447, Taiwan
| | - Praveen Kumar Korla
- Institute of Biomedical Sciences, National Sun Yatsen University, Kaohsiung, 80424, Taiwan
| | - Hui-Jye Chen
- School of Medicine, China Medical University, Taichung, 40402, Taiwan
| | - Chung-Ming Lin
- Department of Biotechnology, Ming Chuan University, Taoyuan, 33348, Taiwan
| | - Ming-Hsui Tsai
- Department of Otolaryngology, China Medical University Hospital, Taichung, 40447, Taiwan
| | - Chun-Hung Hua
- Department of Otolaryngology, China Medical University Hospital, Taichung, 40447, Taiwan
| | - Chia-Ing Jan
- Department of Pathology, China Medical University Hospital, Taichung, 40447, Taiwan
| | - Natini Jinawath
- Program in Translation Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, 10400, Thailand
| | - Chia-Chen Wu
- Institute of Biomedical Sciences, National Sun Yatsen University, Kaohsiung, 80424, Taiwan
| | - Chih-Mei Chen
- Human Genetic Center, China Medical University Hospital, Taichung, 40447, Taiwan
| | - Brian Yu-Ting Kuo
- Institute of Biomedical Sciences, National Sun Yatsen University, Kaohsiung, 80424, Taiwan
| | - Li-Wen Chen
- Institute of Biomedical Sciences, National Sun Yatsen University, Kaohsiung, 80424, Taiwan
| | - Jacky Yang
- Institute of Biomedical Sciences, National Sun Yatsen University, Kaohsiung, 80424, Taiwan
| | - Tritium Hwang
- Institute of Biomedical Sciences, National Sun Yatsen University, Kaohsiung, 80424, Taiwan
| | - Jim Jinn-Chyuan Sheu
- Human Genetic Center, China Medical University Hospital, Taichung, 40447, Taiwan. .,School of Chinese Medicine, China Medical University, Taichung, 40402, Taiwan. .,Institute of Biomedical Sciences, National Sun Yatsen University, Kaohsiung, 80424, Taiwan. .,Department of Health and Nutrition Biotechnology, Asia University, Taichung, 41354, Taiwan.
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11
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Abstract
One of the hallmarks of cancer is the formation of oncogenic fusion genes as a result of chromosomal translocations. Fusion genes are presumed to form before fusion RNA expression. However, studies have reported the presence of fusion RNAs in individuals who were negative for chromosomal translocations. These observations give rise to "the cart before the horse" hypothesis, in which the genesis of a fusion RNA precedes the fusion gene. The fusion RNA then guides the genomic rearrangements that ultimately result in a gene fusion. However, RNA-mediated genomic rearrangements in mammalian cells have never been demonstrated. Here we provide evidence that expression of a chimeric RNA drives formation of a specified gene fusion via genomic rearrangement in mammalian cells. The process is: (i) specified by the sequence of chimeric RNA involved, (ii) facilitated by physiological hormone levels, (iii) permissible regardless of intrachromosomal (TMPRSS2-ERG) or interchromosomal (TMPRSS2-ETV1) fusion, and (iv) can occur in normal cells before malignant transformation. We demonstrate that, contrary to "the cart before the horse" model, it is the antisense rather than sense chimeric RNAs that effectively drive gene fusion, and that this disparity can be explained by transcriptional conflict. Furthermore, we identified an endogenous RNA AZI1 that functions as the "initiator" RNA to induce TMPRSS2-ERG fusion. RNA-driven gene fusion demonstrated in this report provides important insight in early disease mechanisms, and could have fundamental implications in the biology of mammalian genome stability, as well as gene-editing technology via mechanisms native to mammalian cells.
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12
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Wu P, Yang S, Singh S, Qin F, Kumar S, Wang L, Ma D, Li H. The Landscape and Implications of Chimeric RNAs in Cervical Cancer. EBioMedicine 2018; 37:158-167. [PMID: 30389505 PMCID: PMC6286271 DOI: 10.1016/j.ebiom.2018.10.059] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/23/2018] [Accepted: 10/24/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Gene fusions and fusion products have been proven to be ideal biomarkers and drug targets for cancer. Even though a comprehensive study of cervical cancer has been conducted as part of the Cancer Genome Atlas (TCGA) project, few recurrent gene fusions have been found, and none above 3% of frequency. METHODS We believe that chimeric fusion RNAs generated by intergenic splicing represent a new repertoire of biomarkers and/or therapeutic targets. However, they would be missed when only genome sequences and fusions at DNA level are considered. We performed extensive data mining for chimeric RNAs using both our and TCGA cervical cancer RNA-Seq datasets. Multiple criteria were applied. We analyzed the landscape of chimeric RNAs at various levels, and from different angles. FINDINGS The chimeric RNA landscape changed as different filters were applied. 15 highly frequent (>10%) chimeric RNAs were identified. LHX6-NDUFA8 was detected exclusively in cervical cancer tissues and Pap smears, but not in normal controls. Mechanistically, it is not due to interstitial deletion, but a product of cis-splicing between adjacent genes. Silencing of another recurrent chimera, SLC2A11-MIF, resulted in cell cycle arrest and reduced cellular proliferation. This effect is unique to the chimera, and not shared by the two parental genes. INTERPRETATION Highly frequent chimeric RNAs are present in cervical cancers. They can be formed by intergenic splicing. Some have clear implications as potential biomarkers, or for shedding new light on the biology of the disease. FUND: Stand Up To Cancer and the National Science Foundation of China.
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Affiliation(s)
- Peng Wu
- The Key Laboratory of Cancer Invasion and Metastasis of the Ministry of Education of China, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Shuo Yang
- The Key Laboratory of Cancer Invasion and Metastasis of the Ministry of Education of China, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Sandeep Singh
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Fujun Qin
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Shailesh Kumar
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA; National Institute of Plant Genome Research (NIPGR), New Delhi 110067, India
| | - Ling Wang
- The Key Laboratory of Cancer Invasion and Metastasis of the Ministry of Education of China, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Ding Ma
- The Key Laboratory of Cancer Invasion and Metastasis of the Ministry of Education of China, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
| | - Hui Li
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA; School of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450001, China.
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13
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MYC-containing amplicons in acute myeloid leukemia: genomic structures, evolution, and transcriptional consequences. Leukemia 2018; 32:2152-2166. [PMID: 29467491 PMCID: PMC6170393 DOI: 10.1038/s41375-018-0033-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 10/27/2017] [Accepted: 11/13/2017] [Indexed: 01/05/2023]
Abstract
Double minutes (dmin), homogeneously staining regions, and ring chromosomes are vehicles of gene amplification in cancer. The underlying mechanism leading to their formation as well as their structure and function in acute myeloid leukemia (AML) remain mysterious. We combined a range of high-resolution genomic methods to investigate the architecture and expression pattern of amplicons involving chromosome band 8q24 in 23 cases of AML (AML-amp). This revealed that different MYC-dmin architectures can coexist within the same leukemic cell population, indicating a step-wise evolution rather than a single event origin, such as through chromothripsis. This was supported also by the analysis of the chromothripsis criteria, that poorly matched the model in our samples. Furthermore, we found that dmin could evolve toward ring chromosomes stabilized by neocentromeres. Surprisingly, amplified genes (mainly PVT1) frequently participated in fusion transcripts lacking a corresponding DNA template. We also detected a significant overexpression of the circular RNA of PVT1 (circPVT1) in AML-amp cases versus AML with a normal karyotype. Our results show that 8q24 amplicons in AML are surprisingly plastic DNA structures with an unexpected association to novel fusion transcripts and circular RNAs.
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14
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He Y, Yuan C, Chen L, Lei M, Zellmer L, Huang H, Liao DJ. Transcriptional-Readthrough RNAs Reflect the Phenomenon of "A Gene Contains Gene(s)" or "Gene(s) within a Gene" in the Human Genome, and Thus Are Not Chimeric RNAs. Genes (Basel) 2018; 9:E40. [PMID: 29337901 PMCID: PMC5793191 DOI: 10.3390/genes9010040] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 12/29/2017] [Accepted: 01/07/2018] [Indexed: 02/06/2023] Open
Abstract
Tens of thousands of chimeric RNAs, i.e., RNAs with sequences of two genes, have been identified in human cells. Most of them are formed by two neighboring genes on the same chromosome and are considered to be derived via transcriptional readthrough, but a true readthrough event still awaits more evidence and trans-splicing that joins two transcripts together remains as a possible mechanism. We regard those genomic loci that are transcriptionally read through as unannotated genes, because their transcriptional and posttranscriptional regulations are the same as those of already-annotated genes, including fusion genes formed due to genetic alterations. Therefore, readthrough RNAs and fusion-gene-derived RNAs are not chimeras. Only those two-gene RNAs formed at the RNA level, likely via trans-splicing, without corresponding genes as genomic parents, should be regarded as authentic chimeric RNAs. However, since in human cells, procedural and mechanistic details of trans-splicing have never been disclosed, we doubt the existence of trans-splicing. Therefore, there are probably no authentic chimeras in humans, after readthrough and fusion-gene derived RNAs are all put back into the group of ordinary RNAs. Therefore, it should be further determined whether in human cells all two-neighboring-gene RNAs are derived from transcriptional readthrough and whether trans-splicing truly exists.
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Affiliation(s)
- Yan He
- Key Lab of Endemic and Ethnic Diseases of the Ministry of Education of China in Guizhou Medical University, Guiyang 550004, Guizhou, China.
| | - Chengfu Yuan
- Department of Biochemistry, China Three Gorges University, Yichang City 443002, Hubei, China.
| | - Lichan Chen
- Hormel Institute, University of Minnesota, Austin, MN 55912, USA.
| | - Mingjuan Lei
- Hormel Institute, University of Minnesota, Austin, MN 55912, USA.
| | - Lucas Zellmer
- Masonic Cancer Center, University of Minnesota, 435 E. River Road, Minneapolis, MN 55455, USA.
| | - Hai Huang
- School of Clinical Laboratory Science, Guizhou Medical University, Guiyang 550004, Guizhou, China.
| | - Dezhong Joshua Liao
- Key Lab of Endemic and Ethnic Diseases of the Ministry of Education of China in Guizhou Medical University, Guiyang 550004, Guizhou, China.
- Department of Pathology, Guizhou Medical University Hospital, Guiyang 550004, Guizhou, China.
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15
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Chwalenia K, Facemire L, Li H. Chimeric RNAs in cancer and normal physiology. WILEY INTERDISCIPLINARY REVIEWS-RNA 2017; 8. [DOI: 10.1002/wrna.1427] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 04/27/2017] [Accepted: 04/28/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Katarzyna Chwalenia
- Department of Pathology, School of Medicine; University of Virginia; Charlottesville VA USA
| | - Loryn Facemire
- Department of Pathology, School of Medicine; University of Virginia; Charlottesville VA USA
| | - Hui Li
- Department of Pathology, School of Medicine; University of Virginia; Charlottesville VA USA
- Department of Biochemistry and Molecular Genetics, School of Medicine; University of Virginia; Charlottesville VA USA
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16
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It Is Imperative to Establish a Pellucid Definition of Chimeric RNA and to Clear Up a Lot of Confusion in the Relevant Research. Int J Mol Sci 2017; 18:ijms18040714. [PMID: 28350330 PMCID: PMC5412300 DOI: 10.3390/ijms18040714] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/15/2017] [Accepted: 03/17/2017] [Indexed: 12/27/2022] Open
Abstract
There have been tens of thousands of RNAs deposited in different databases that contain sequences of two genes and are coined chimeric RNAs, or chimeras. However, "chimeric RNA" has never been lucidly defined, partly because "gene" itself is still ill-defined and because the means of production for many RNAs is unclear. Since the number of putative chimeras is soaring, it is imperative to establish a pellucid definition for it, in order to differentiate chimeras from regular RNAs. Otherwise, not only will chimeric RNA studies be misled but also characterization of fusion genes and unannotated genes will be hindered. We propose that only those RNAs that are formed by joining two RNA transcripts together without a fusion gene as a genomic basis should be regarded as authentic chimeras, whereas those RNAs transcribed as, and cis-spliced from, single transcripts should not be deemed as chimeras. Many RNAs containing sequences of two neighboring genes may be transcribed via a readthrough mechanism, and thus are actually RNAs of unannotated genes or RNA variants of known genes, but not chimeras. In today's chimeric RNA research, there are still several key flaws, technical constraints and understudied tasks, which are also described in this perspective essay.
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17
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Abstract
Gene fusions and their encoded products (fusion RNAs and proteins) are viewed as one of the hallmarks of cancer. Traditionally, they were thought to be generated solely by chromosomal rearrangements. However, recent discoveries of trans-splicing and cis-splicing events between neighboring genes, suggest that there are other mechanisms to generate chimeric fusion RNAs without corresponding changes in DNA. In addition, chimeric RNAs have been detected in normal physiology, complicating the use of fusions in cancer detection and therapy. On the other hand, "intergenically spliced" fusion RNAs represent a new repertoire of biomarkers and therapeutic targets. Here, we review current knowledge on chimeric RNAs and implications for cancer detection and treatment, and discuss outstanding questions for the advancement of the field.
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Affiliation(s)
- Yuemeng Jia
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908
| | - Zhongqiu Xie
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908
| | - Hui Li
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Charlottesville, VA 22908
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18
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Olsen TK, Panagopoulos I, Gorunova L, Micci F, Andersen K, Kilen Andersen H, Meling TR, Due-Tønnessen B, Scheie D, Heim S, Brandal P. Novel fusion genes and chimeric transcripts in ependymal tumors. Genes Chromosomes Cancer 2016; 55:944-953. [PMID: 27401149 DOI: 10.1002/gcc.22392] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 07/03/2016] [Accepted: 07/03/2016] [Indexed: 01/14/2023] Open
Abstract
We have previously identified two ALK rearrangements in a subset of ependymal tumors using a combination of cytogenetic data and RNA sequencing. The aim of this study was to perform an unbiased search for fusion transcripts in our entire series of ependymal tumors. Fusion analysis was performed using the FusionCatcher algorithm on 12 RNA-sequenced ependymal tumors. Candidate transcripts were prioritized based on the software's filtering and manual visualization using the BLAST (Basic Local Alignment Search Tool) and BLAT (BLAST-like alignment tool) tools. Genomic and reverse transcriptase PCR with subsequent Sanger sequencing was used to validate the potential fusions. Fluorescent in situ hybridization (FISH) using locus-specific probes was also performed. A total of 841 candidate chimeric transcripts were identified in the 12 tumors, with an average of 49 unique candidate fusions per tumor. After algorithmic and manual filtering, the final list consisted of 24 potential fusion events. Raw RNA-seq read sequences and PCR validation supports two novel fusion genes: a reciprocal fusion gene involving UQCR10 and C1orf194 in an adult spinal ependymoma and a TSPAN4-CD151 fusion gene in a pediatric infratentorial anaplastic ependymoma. Our previously reported ALK rearrangements and the RELA and YAP1 fusions found in supratentorial ependymomas were until now the only known fusion genes present in ependymal tumors. The chimeric transcripts presented here are the first to be reported in infratentorial or spinal ependymomas. Further studies are required to characterize the genomic rearrangements causing these fusion genes, as well as the frequency and functional importance of the fusions. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Thale Kristin Olsen
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, Oslo University Hospital, Norway. .,Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Norway. .,Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway.
| | - Ioannis Panagopoulos
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, Oslo University Hospital, Norway.,Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Norway
| | - Ludmila Gorunova
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, Oslo University Hospital, Norway.,Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Norway
| | - Francesca Micci
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, Oslo University Hospital, Norway.,Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Norway
| | - Kristin Andersen
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, Oslo University Hospital, Norway
| | - Hege Kilen Andersen
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, Oslo University Hospital, Norway
| | | | | | - David Scheie
- Department of Pathology, Rigshospitalet, Copenhagen, Denmark.,Department of Pathology, Oslo University Hospital, Norway
| | - Sverre Heim
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, Oslo University Hospital, Norway.,Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Norway.,Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Norway
| | - Petter Brandal
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, Oslo University Hospital, Norway.,Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Norway.,Department of Oncology, Oslo University Hospital-The Norwegian Radium Hospital, Norway
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19
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Lei Q, Li C, Zuo Z, Huang C, Cheng H, Zhou R. Evolutionary Insights into RNA trans-Splicing in Vertebrates. Genome Biol Evol 2016; 8:562-77. [PMID: 26966239 PMCID: PMC4824033 DOI: 10.1093/gbe/evw025] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Pre-RNA splicing is an essential step in generating mature mRNA. RNA trans-splicing combines two separate pre-mRNA molecules to form a chimeric non-co-linear RNA, which may exert a function distinct from its original molecules. Trans-spliced RNAs may encode novel proteins or serve as noncoding or regulatory RNAs. These novel RNAs not only increase the complexity of the proteome but also provide new regulatory mechanisms for gene expression. An increasing amount of evidence indicates that trans-splicing occurs frequently in both physiological and pathological processes. In addition, mRNA reprogramming based on trans-splicing has been successfully applied in RNA-based therapies for human genetic diseases. Nevertheless, clarifying the extent and evolution of trans-splicing in vertebrates and developing detection methods for trans-splicing remain challenging. In this review, we summarize previous research, highlight recent advances in trans-splicing, and discuss possible splicing mechanisms and functions from an evolutionary viewpoint.
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Affiliation(s)
- Quan Lei
- Department of Genetics, College of Life Sciences, Wuhan University, P.R. China
| | - Cong Li
- Department of Genetics, College of Life Sciences, Wuhan University, P.R. China
| | - Zhixiang Zuo
- Department of Genetics, College of Life Sciences, Wuhan University, P.R. China
| | - Chunhua Huang
- Department of Cell Biology, College of Life Sciences, Wuhan University, P.R. China
| | - Hanhua Cheng
- Department of Cell Biology, College of Life Sciences, Wuhan University, P.R. China
| | - Rongjia Zhou
- Department of Genetics, College of Life Sciences, Wuhan University, P.R. China
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20
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Babiceanu M, Qin F, Xie Z, Jia Y, Lopez K, Janus N, Facemire L, Kumar S, Pang Y, Qi Y, Lazar IM, Li H. Recurrent chimeric fusion RNAs in non-cancer tissues and cells. Nucleic Acids Res 2016; 44:2859-72. [PMID: 26837576 PMCID: PMC4824105 DOI: 10.1093/nar/gkw032] [Citation(s) in RCA: 136] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 01/11/2016] [Indexed: 11/13/2022] Open
Abstract
Gene fusions and their products (RNA and protein) were once thought to be unique features to cancer. However, chimeric RNAs can also be found in normal cells. Here, we performed, curated and analyzed nearly 300 RNA-Seq libraries covering 30 different non-neoplastic human tissues and cells as well as 15 mouse tissues. A large number of fusion transcripts were found. Most fusions were detected only once, while 291 were seen in more than one sample. We focused on the recurrent fusions and performed RNA and protein level validations on a subset. We characterized these fusions based on various features of the fusions, and their parental genes. They tend to be expressed at higher levels relative to their parental genes than the non-recurrent ones. Over half of the recurrent fusions involve neighboring genes transcribing in the same direction. A few sequence motifs were found enriched close to the fusion junction sites. We performed functional analyses on a few widely expressed fusions, and found that silencing them resulted in dramatic reduction in normal cell growth and/or motility. Most chimeras use canonical splicing sites, thus are likely products of 'intergenic splicing'. We also explored the implications of these non-pathological fusions in cancer and in evolution.
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Affiliation(s)
- Mihaela Babiceanu
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Fujun Qin
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Zhongqiu Xie
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Yuemeng Jia
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Kevin Lopez
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Nick Janus
- Department of Computer Science, University of Virginia, Charlottesville, VA 22908, USA
| | - Loryn Facemire
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Shailesh Kumar
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Yuwei Pang
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Yanjun Qi
- Department of Computer Science, University of Virginia, Charlottesville, VA 22908, USA
| | - Iulia M Lazar
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Hui Li
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
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21
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Abstract
Structural chromosome rearrangements may result in the exchange of coding or regulatory DNA sequences between genes. Many such gene fusions are strong driver mutations in neoplasia and have provided fundamental insights into the disease mechanisms that are involved in tumorigenesis. The close association between the type of gene fusion and the tumour phenotype makes gene fusions ideal for diagnostic purposes, enabling the subclassification of otherwise seemingly identical disease entities. In addition, many gene fusions add important information for risk stratification, and increasing numbers of chimeric proteins encoded by the gene fusions serve as specific targets for treatment, resulting in dramatically improved patient outcomes. In this Timeline article, we describe the spectrum of gene fusions in cancer and how the methods to identify them have evolved, and also discuss conceptual implications of current, sequencing-based approaches for detection.
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Affiliation(s)
- Fredrik Mertens
- Department of Clinical Genetics, Lund University and Skåne University Hospital, SE-221 85 Lund, Sweden
| | - Bertil Johansson
- Department of Clinical Genetics, Lund University and Skåne University Hospital, SE-221 85 Lund, Sweden
| | - Thoas Fioretos
- Department of Clinical Genetics, Lund University and Skåne University Hospital, SE-221 85 Lund, Sweden
| | - Felix Mitelman
- Department of Clinical Genetics, Lund University and Skåne University Hospital, SE-221 85 Lund, Sweden
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22
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Peng Z, Yuan C, Zellmer L, Liu S, Xu N, Liao DJ. Hypothesis: Artifacts, Including Spurious Chimeric RNAs with a Short Homologous Sequence, Caused by Consecutive Reverse Transcriptions and Endogenous Random Primers. J Cancer 2015; 6:555-67. [PMID: 26000048 PMCID: PMC4439942 DOI: 10.7150/jca.11997] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 04/02/2015] [Indexed: 12/21/2022] Open
Abstract
Recent RNA-sequencing technology and associated bioinformatics have led to identification of tens of thousands of putative human chimeric RNAs, i.e. RNAs containing sequences from two different genes, most of which are derived from neighboring genes on the same chromosome. In this essay, we redefine "two neighboring genes" as those producing individual transcripts, and point out two known mechanisms for chimeric RNA formation, i.e. transcription from a fusion gene or trans-splicing of two RNAs. By our definition, most putative RNA chimeras derived from canonically-defined neighboring genes may either be technical artifacts or be cis-splicing products of 5'- or 3'-extended RNA of either partner that is redefined herein as an unannotated gene, whereas trans-splicing events are rare in human cells. Therefore, most authentic chimeric RNAs result from fusion genes, about 1,000 of which have been identified hitherto. We propose a hypothesis of "consecutive reverse transcriptions (RTs)", i.e. another RT reaction following the previous one, for how most spurious chimeric RNAs, especially those containing a short homologous sequence, may be generated during RT, especially in RNA-sequencing wherein RNAs are fragmented. We also point out that RNA samples contain numerous RNA and DNA shreds that can serve as endogenous random primers for RT and ensuing polymerase chain reactions (PCR), creating artifacts in RT-PCR.
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Affiliation(s)
- Zhiyu Peng
- 1. Beijing Genomics Institute at Shenzhen, Building No.11, Beishan Industrial Zone, Yantian District, Shenzhen 518083, P. R. China
| | - Chengfu Yuan
- 2. Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Lucas Zellmer
- 2. Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Siqi Liu
- 3. CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, P. R. China
| | - Ningzhi Xu
- 4. Laboratory of Cell and Molecular Biology, Cancer Institute, Chinese Academy of Medical Science, Beijing 100021, P. R. China
| | - D Joshua Liao
- 2. Hormel Institute, University of Minnesota, Austin, MN 55912, USA
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23
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Mertens F, Tayebwa J. Evolving techniques for gene fusion detection in soft tissue tumours. Histopathology 2013; 64:151-62. [PMID: 24320890 DOI: 10.1111/his.12272] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Chromosomal rearrangements resulting in the fusion of coding parts from two genes or in the exchange of regulatory sequences are present in approximately 20% of all human neoplasms. More than 1000 such gene fusions have now been described, with close to 100 of them in soft tissue tumours. Although little is still known about the functional outcome of many of these gene fusions, it is well established that most of them have a major impact on tumorigenesis. Furthermore, the strong association between type of gene fusion and morphological subtype makes them highly useful diagnostic markers. Until recently, the vast majority of gene fusions were identified through molecular cytogenetic characterization of rearrangements detected at chromosome banding analysis, followed by use of the reverse transcriptase-polymerase chain reaction (RT-PCR) and Sanger sequencing. With the advent of next-generation sequencing (NGS) technologies, notably of whole transcriptomes or all poly-A(+) mRNA molecules, the possibility of detecting new gene fusions has increased dramatically. Already, a large number of novel gene fusions have been identified through NGS approaches and it can be predicted that these technologies soon will become standard diagnostic clinical tools.
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Affiliation(s)
- Fredrik Mertens
- Department of Clinical Genetics, University and Regional Laboratories, Lund University, Lund, Sweden
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24
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Nitsche A, Doose G, Tafer H, Robinson M, Saha NR, Gerdol M, Canapa A, Hoffmann S, Amemiya CT, Stadler PF. Atypical RNAs in the coelacanth transcriptome. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2013; 322:342-51. [PMID: 24174405 DOI: 10.1002/jez.b.22542] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 07/22/2013] [Accepted: 08/16/2013] [Indexed: 01/15/2023]
Abstract
Circular and apparently trans-spliced RNAs have recently been reported as abundant types of transcripts in mammalian transcriptome data. Both types of non-colinear RNAs are also abundant in RNA-seq of different tissue from both the African and the Indonesian coelacanth. We observe more than 8,000 lincRNAs with normal gene structure and several thousands of circularized and trans-spliced products, showing that such atypical RNAs form a substantial contribution to the transcriptome. Surprisingly, the majority of the circularizing and trans-connecting splice junctions are unique to atypical forms, that is, are not used in normal isoforms.
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Affiliation(s)
- Anne Nitsche
- Department of Computer Science, Bioinformatics Group, University of Leipzig, Leipzig, Germany; Interdisciplinary Center for Bioinformatics, University of Leipzig, Leipzig, Germany
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Yuan H, Qin F, Movassagh M, Park H, Golden W, Xie Z, Zhang P, Sklar J, Li H. A chimeric RNA characteristic of rhabdomyosarcoma in normal myogenesis process. Cancer Discov 2013; 3:1394-403. [PMID: 24089019 DOI: 10.1158/2159-8290.cd-13-0186] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
UNLABELLED Gene fusions and their chimeric products are common features of neoplasia. Given that many cancers arise by the dysregulated recapitulation of processes in normal development, we hypothesized that comparable chimeric gene products may exist in normal cells. Here, we show that a chimeric RNA, PAX3-FOXO1, identical to that found in alveolar rhabdomyosarcoma, is transiently present in cells undergoing differentiation from pluripotent cells into skeletal muscle. Unlike cells of rhabdomyosarcoma, these cells do not seem to harbor the t(2;13) chromosomal translocation. Importantly, both PAX3-FOXO1 RNA and protein could be detected in the samples of normal fetal muscle. Overexpression of the chimera led to continuous expression of MYOD and MYOG-two myogenic markers that are overexpressed in rhabdomyosarcoma cells. Our results are consistent with a developmental role of a specific chimeric RNA generated in normal cells without the corresponding chromosomal rearrangement at the DNA level seen in neoplastic cells presumably of the same lineage. SIGNIFICANCE A chimeric fusion RNA, PAX3-FOXO1, associated with alveolar rhabdomyosarcoma, is also present in normal non-cancer cells and tissues. Its transient expression nature and the absence of t(2;13) chromosomal translocation are consistent with a posttranscriptional mechanism. When constantly expressed, PAX3-FOXO1 interfered with the muscle differentiation process, which presumably contributes to tumorigenesis.
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Affiliation(s)
- Huiling Yuan
- 1Department of Pathology and 2University of Virginia Cancer Center, University of Virginia, Charlottesville, Virginia; and 3Department of Pathology, Yale University, New Haven, Connecticut
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The role of canonical and noncanonical pre-mRNA splicing in plant stress responses. BIOMED RESEARCH INTERNATIONAL 2012; 2013:264314. [PMID: 23509698 PMCID: PMC3591102 DOI: 10.1155/2013/264314] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 10/02/2012] [Accepted: 10/11/2012] [Indexed: 11/17/2022]
Abstract
Plants are sessile organisms capable of adapting to various environmental constraints, such as high or low temperatures, drought, soil salinity, or pathogen attack. To survive the unfavorable conditions, plants actively employ pre-mRNA splicing as a mechanism to regulate expression of stress-responsive genes and reprogram intracellular regulatory networks. There is a growing evidence that various stresses strongly affect the frequency and diversity of alternative splicing events in the stress-responsive genes and lead to an increased accumulation of mRNAs containing premature stop codons, which in turn have an impact on plant stress response. A number of studies revealed that some mRNAs involved in plant stress response are spliced counter to the traditional conception of alternative splicing. Such noncanonical mRNA splicing events include trans-splicing, intraexonic deletions, or variations affecting multiple exons and often require short direct repeats to occur. The noncanonical alternative splicing, along with common splicing events, targets the spliced transcripts to degradation through nonsense-mediated mRNA decay or leads to translation of truncated proteins. Investigation of the diversity, biological consequences, and mechanisms of the canonical and noncanonical alternative splicing events will help one to identify those transcripts which are promising for using in genetic engineering and selection of stress-tolerant plants.
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Do non-genomically encoded fusion transcripts cause recurrent chromosomal translocations? Cancers (Basel) 2012; 4:1036-49. [PMID: 24213499 PMCID: PMC3712730 DOI: 10.3390/cancers4041036] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 09/14/2012] [Accepted: 10/09/2012] [Indexed: 12/27/2022] Open
Abstract
We among others have recently demonstrated that normal cells produce “fusion mRNAs”. These fusion mRNAs do not derive from rearranged genomic loci, but rather they are derived from “early-terminated transcripts” (ETTs). Premature transcriptional termination takes place in intronic sequences that belong to “breakpoint cluster regions”. One important property of ETTs is that they exhibit an unsaturated splice donor site. This results in: (1) splicing to “cryptic exons” present in the final intron; (2) Splicing to another transcript of the same gene (intragenic trans-splicing), resulting in “exon repetitions”; (3) splicing to a transcript of another gene (intergenic trans-splicing), leading to “non-genomically encoded fusion transcripts” (NGEFTs). These NGEFTs bear the potential risk to influence DNA repair processes, since they share identical nucleotides with their DNA of origin, and thus, could be used as “guidance RNA” for DNA repair processes. Here, we present experimental data about four other genes. Three of them are associated with hemato-malignancies (ETV6, NUP98 and RUNX1), while one is associated with solid tumors (EWSR1). Our results demonstrate that all genes investigated so far (MLL, AF4, AF9, ENL, ELL, ETV6, NUP98, RUNX1 and EWSR1) display ETTs and produce transpliced mRNA species, indicating that this is a genuine property of translocating genes.
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