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Li X, Yu H, Li D, Liu N. LINE-1 transposable element renaissance in aging and age-related diseases. Ageing Res Rev 2024; 100:102440. [PMID: 39059477 DOI: 10.1016/j.arr.2024.102440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 07/16/2024] [Accepted: 07/24/2024] [Indexed: 07/28/2024]
Abstract
Transposable elements (TEs) are essential components of eukaryotic genomes and are subject to stringent regulatory mechanisms to avoid their potentially deleterious effects. However, numerous studies have verified the resurrection of TEs, particularly long interspersed nuclear element-1 (LINE-1), during preimplantation development, aging, cancer, and other age-related diseases. The LINE-1 family has also been implicated in several aging-related processes, including genomic instability, loss of heterochromatin, DNA methylation, and the senescence-associated secretory phenotype (SASP). Additionally, the role of the LINE-1 family in cancer development has also been substantiated. Research in this field has offered valuable insights into the functional mechanisms underlying LINE-1 activity, enhancing our understanding of aging regulation. This review provides a comprehensive summary of current findings on LINE-1 and their roles in aging and age-related diseases.
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Affiliation(s)
- Xiang Li
- School of Medicine, Nankai University, Tianjin, 300071, China.
| | - Huaxin Yu
- School of Medicine, Nankai University, Tianjin, 300071, China.
| | - Dong Li
- School of Medicine, Nankai University, Tianjin, 300071, China.
| | - Na Liu
- School of Medicine, Nankai University, Tianjin, 300071, China.
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2
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Switzer CH. Non-canonical nitric oxide signalling and DNA methylation: Inflammation induced epigenetic alterations and potential drug targets. Br J Pharmacol 2023. [PMID: 38116806 DOI: 10.1111/bph.16302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/29/2023] [Accepted: 09/20/2023] [Indexed: 12/21/2023] Open
Abstract
DNA methylation controls DNA accessibility to transcription factors and other regulatory proteins, thereby affecting gene expression and hence cellular identity and function. As epigenetic modifications control the transcriptome, epigenetic dysfunction is strongly associated with pathological conditions and ageing. The development of pharmacological agents that modulate the activity of major epigenetic proteins are in pre-clinical development and clinical use. However, recent publications have identified novel redox-based signalling pathways, and therefore novel drug targets, that may exert epigenetic effects. This review will discuss the recent developments in nitric oxide (NO) signalling on DNA methylation as well as potential epigenetic drug targets that have emerged from the intersection of inflammation/redox biology and epigenetic regulation.
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Affiliation(s)
- Christopher H Switzer
- William Harvey Research Institute, Barts & The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
- Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
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3
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Abstract
N6-Methyladenosine (m6A) is one of the most abundant modifications of the epitranscriptome and is found in cellular RNAs across all kingdoms of life. Advances in detection and mapping methods have improved our understanding of the effects of m6A on mRNA fate and ribosomal RNA function, and have uncovered novel functional roles in virtually every species of RNA. In this Review, we explore the latest studies revealing roles for m6A-modified RNAs in chromatin architecture, transcriptional regulation and genome stability. We also summarize m6A functions in biological processes such as stem-cell renewal and differentiation, brain function, immunity and cancer progression.
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Affiliation(s)
- Konstantinos Boulias
- Division of Newborn Medicine, Boston Children's Hospital, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
- Harvard Medical School Initiative for RNA Medicine, Boston, MA, USA
| | - Eric Lieberman Greer
- Division of Newborn Medicine, Boston Children's Hospital, Boston, MA, USA.
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA.
- Harvard Medical School Initiative for RNA Medicine, Boston, MA, USA.
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4
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Wang X, Ye L, Li B. Development of a Genomic Instability-Derived lncRNAs-Based Risk Signature as a Predictor of Prognosis for Endometrial Cancer. J Cancer 2022; 13:2213-2225. [PMID: 35517417 PMCID: PMC9066205 DOI: 10.7150/jca.65581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 03/06/2022] [Indexed: 11/30/2022] Open
Abstract
Endometrial cancer (EC) ranks fourth in the incidence rate among the most frequent gynaecological malignancies reported in the developed countries. Approximately 280,000 endometrial cancer cases are reported worldwide every year. Genomic instability and mutation are some of the favourable characteristics of human malignancies such as endometrial cancer. Studies have established that the majority of genomic mutations in human malignancies are found in the chromosomal regions that do not code for proteins. In addition, the majority of transcriptional products of these mutations are long non-coding RNAs (lncRNAs). In this study, 78 lncRNA genes were found on the basis of their mutation counts. Then, these lncRNAs were investigated to determine their relationship with genomic instability through hierarchical cluster analysis, mutation analysis, and differential analysis of driving genes responsible for genomic instability. The prognostic value of these lncRNAs was also assessed in patients with EC, and a risk factor score formula composed of 15 lncRNAs was constructed. We then identified this formula as genome instability-derived lncRNA-based gene signature (GILncSig), which stratified patients into high- and low-risk groups with significantly different outcome. And GILncSig was further validated in multiple independent patient cohorts as a prognostic factor of other clinicopathological features, such as stage, grade, overall survival rate. We observed that a high-risk score is often associated with an unfavourable prognosis in patients with EC.
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Affiliation(s)
- Xiaojun Wang
- Department of Gynaecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 200092, China
| | - Lei Ye
- Department of Gynaecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 200092, China
| | - Bilan Li
- Department of Gynaecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 200092, China
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5
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Shah AH, Govindarajan V, Doucet-O'Hare TT, Rivas S, Ampie L, DeMarino C, Banasavadi-Siddegowda YK, Zhang Y, Johnson KR, Almsned F, Gilbert MR, Heiss JD, Nath A. Differential expression of an endogenous retroviral element [HERV-K(HML-6)] is associated with reduced survival in glioblastoma patients. Sci Rep 2022; 12:6902. [PMID: 35477752 PMCID: PMC9046263 DOI: 10.1038/s41598-022-10914-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 04/04/2022] [Indexed: 11/09/2022] Open
Abstract
Comprising approximately 8% of our genome, Human Endogenous RetroViruses (HERVs) represent a class of germline retroviral infections that are regulated through epigenetic modifications. In cancer cells, which often have epigenetic dysregulation, HERVs have been implicated as potential oncogenic drivers. However, their role in gliomas is not known. Given the link between HERV expression in cancer cell lines and the distinct epigenetic dysregulation in gliomas, we utilized a tailored bioinformatic pipeline to characterize and validate the glioma retrotranscriptome and correlate HERV expression with locus-specific epigenetic modifications. We identified robust overexpression of multiple HERVs in our cell lines, including a retroviral transcript, HML-6, at 19q13.43b in glioblastoma cells. HERV expression inversely correlated with loci-specific DNA methylation. HML-6 contains an intact open reading frame encoding a small envelope protein, ERVK3-1. Increased expression of ERVK3-1 in GBM patients is associated with a poor prognosis independent of IDH-mutational status. Our results suggest that not only is HML-6 uniquely overexpressed in highly invasive cell lines and tissue samples, but also its gene product, ERVK3-1, may be associated with reduced survival in GBM patients. These results may have implications for both the tumor biology of GBM and the role of ERVK3-1 as a potential therapeutic target.
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Affiliation(s)
- Ashish H Shah
- Surgical Neurology Branch, National Institutes of Health, National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, MD, USA.
| | - Vaidya Govindarajan
- Department of Neurosurgery, University of Miami School of Medicine, Miami, FL, USA
| | - Tara T Doucet-O'Hare
- Center for Cancer Research (CCR), National Institutes of Health, National Cancer Institute (NCI), Neuro-Oncology Branch (NOB), Bethesda, MD, USA
| | - Sarah Rivas
- Surgical Neurology Branch, National Institutes of Health, National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, MD, USA
| | - Leo Ampie
- Surgical Neurology Branch, National Institutes of Health, National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, MD, USA
| | - Catherine DeMarino
- Surgical Neurology Branch, National Institutes of Health, National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, MD, USA
| | | | - Yong Zhang
- Bioinformatics Section, National Institutes of Health, National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, MD, USA
| | - Kory R Johnson
- Bioinformatics Section, National Institutes of Health, National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, MD, USA
| | - Fahad Almsned
- Bioinformatics Section, National Institutes of Health, National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, MD, USA
| | - Mark R Gilbert
- Center for Cancer Research (CCR), National Institutes of Health, National Cancer Institute (NCI), Neuro-Oncology Branch (NOB), Bethesda, MD, USA
| | - John D Heiss
- Surgical Neurology Branch, National Institutes of Health, National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, MD, USA
| | - Avindra Nath
- Surgical Neurology Branch, National Institutes of Health, National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, MD, USA
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6
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Yang C, Guo X, Li J, Han J, Jia L, Wen HL, Sun C, Wang X, Zhang B, Li J, Chi Y, An T, Wang Y, Wang Z, Li H, Li L. Significant Upregulation of HERV-K (HML-2) Transcription Levels in Human Lung Cancer and Cancer Cells. Front Microbiol 2022; 13:850444. [PMID: 35359739 PMCID: PMC8960717 DOI: 10.3389/fmicb.2022.850444] [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: 01/07/2022] [Accepted: 02/15/2022] [Indexed: 12/14/2022] Open
Abstract
Lung cancer is the second most common cancer worldwide and the leading cause of cancer death in the world. Therefore, there is an urgent need to develop new and effective biomarkers for diagnosis and treatment. Under this circumstance, human endogenous retroviruses (HERVs) were recently introduced as novel biomarkers for cancer diagnosis. This study focused on the correlation between lung cancer and HERV-K (HML-2) transcription levels. At the cellular level, different types of lung cancer cells and human normal lung epithelial cells were used to analyze the transcription levels of the HERV-K (HML-2) gag, pol, and env genes by RT–qPCR. At the level of lung cancer patients, blood samples with background information from 734 lung cancer patients and 96 healthy persons were collected to analyze the transcription levels of HERV-K (HML-2) gag, pol, and env genes. The results showed that the transcriptional levels of the HERV-K (HML-2) gag, pol, and env genes in lung cancer cells and lung cancer patient blood samples were significantly higher than those in the healthy controls, which was also verified by RNAScope ISH technology. In addition, we also found that there was a correlation between the abnormal transcription levels of HERV-K (HML-2) genes in lung cancer patients and the clinicopathological parameters of lung cancer. We also identified the distribution locations of the gag, pol, and env primer sequences on each chromosome and analyzed the function of these loci. In conclusion, HERV-K (HML-2) genes may be a potential biomarker for the diagnosis of lung cancer.
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Affiliation(s)
- Caiqin Yang
- Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, AMMS, Beijing, China
| | - Xin Guo
- Department of Nutrition and Food Hygiene, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Jianjie Li
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Thoracic Medical Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Jingwan Han
- Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, AMMS, Beijing, China
| | - Lei Jia
- Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, AMMS, Beijing, China
| | - Hong-Ling Wen
- Key Laboratory for the Prevention and Control of Infectious Diseases, Department of Microbiological Laboratory Technology, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Chengxi Sun
- Department of Clinical Laboratory, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Xiaolin Wang
- Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, AMMS, Beijing, China
| | - Bohan Zhang
- Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, AMMS, Beijing, China
| | - Jingyun Li
- Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, AMMS, Beijing, China
| | - Yujia Chi
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Thoracic Medical Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Tongtong An
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Thoracic Medical Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Yuyan Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Thoracic Medical Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Ziping Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Thoracic Medical Oncology, Peking University Cancer Hospital & Institute, Beijing, China
- *Correspondence: Ziping Wang,
| | - Hanping Li
- Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, AMMS, Beijing, China
- Hanping Li,
| | - Lin Li
- Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, AMMS, Beijing, China
- Lin Li,
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7
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Arunkumar G, Baek S, Sturgill D, Bui M, Dalal Y. Oncogenic lncRNAs alter epigenetic memory at a fragile chromosomal site in human cancer cells. SCIENCE ADVANCES 2022; 8:eabl5621. [PMID: 35235361 PMCID: PMC8890707 DOI: 10.1126/sciadv.abl5621] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Chromosome instability is a critical event in cancer progression. Histone H3 variant CENP-A plays a fundamental role in defining centromere identity, structure, and function but is innately overexpressed in several types of solid cancers. In the cancer background, excess CENP-A is deposited ectopically on chromosome arms, including 8q24/cMYC locus, by invading transcription-coupled H3.3 chaperone pathways. Up-regulation of lncRNAs in many cancers correlates with poor prognosis and recurrence in patients. We report that transcription of 8q24-derived oncogenic lncRNAs plays an unanticipated role in altering the 8q24 chromatin landscape by H3.3 chaperone-mediated deposition of CENP-A-associated complexes. Furthermore, a transgene cassette carrying specific 8q24-derived lncRNA integrated into a naïve chromosome locus recruits CENP-A to the new location in a cis-acting manner. These data provide a plausible mechanistic link between locus-specific oncogenic lncRNAs, aberrant local chromatin structure, and the generation of new epigenetic memory at a fragile site in human cancer cells.
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8
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Peze-Heidsieck E, Bonnifet T, Znaidi R, Ravel-Godreuil C, Massiani-Beaudoin O, Joshi RL, Fuchs J. Retrotransposons as a Source of DNA Damage in Neurodegeneration. Front Aging Neurosci 2022; 13:786897. [PMID: 35058771 PMCID: PMC8764243 DOI: 10.3389/fnagi.2021.786897] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/30/2021] [Indexed: 01/09/2023] Open
Abstract
The etiology of aging-associated neurodegenerative diseases (NDs), such as Parkinson’s disease (PD) and Alzheimer’s disease (AD), still remains elusive and no curative treatment is available. Age is the major risk factor for PD and AD, but the molecular link between aging and neurodegeneration is not fully understood. Aging is defined by several hallmarks, some of which partially overlap with pathways implicated in NDs. Recent evidence suggests that aging-associated epigenetic alterations can lead to the derepression of the LINE-1 (Long Interspersed Element-1) family of transposable elements (TEs) and that this derepression might have important implications in the pathogenesis of NDs. Almost half of the human DNA is composed of repetitive sequences derived from TEs and TE mobility participated in shaping the mammalian genomes during evolution. Although most TEs are mutated and no longer mobile, more than 100 LINE-1 elements have retained their full coding potential in humans and are thus retrotransposition competent. Uncontrolled activation of TEs has now been reported in various models of neurodegeneration and in diseased human brain tissues. We will discuss in this review the potential contribution of LINE-1 elements in inducing DNA damage and genomic instability, which are emerging pathological features in NDs. TEs might represent an important molecular link between aging and neurodegeneration, and a potential target for urgently needed novel therapeutic disease-modifying interventions.
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Affiliation(s)
- Eugenie Peze-Heidsieck
- Center for Interdisciplinary Research in Biology (CIRB), CNRS, INSERM, Collège de France, Université PSL, Paris, France
| | - Tom Bonnifet
- Center for Interdisciplinary Research in Biology (CIRB), CNRS, INSERM, Collège de France, Université PSL, Paris, France
| | - Rania Znaidi
- Center for Interdisciplinary Research in Biology (CIRB), CNRS, INSERM, Collège de France, Université PSL, Paris, France
| | - Camille Ravel-Godreuil
- Center for Interdisciplinary Research in Biology (CIRB), CNRS, INSERM, Collège de France, Université PSL, Paris, France
| | - Olivia Massiani-Beaudoin
- Center for Interdisciplinary Research in Biology (CIRB), CNRS, INSERM, Collège de France, Université PSL, Paris, France
| | - Rajiv L Joshi
- Center for Interdisciplinary Research in Biology (CIRB), CNRS, INSERM, Collège de France, Université PSL, Paris, France
| | - Julia Fuchs
- Center for Interdisciplinary Research in Biology (CIRB), CNRS, INSERM, Collège de France, Université PSL, Paris, France
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9
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Ko EJ, Song KS, Ock MS, Choi YH, Kim S, Kim HS, Cha HJ. Expression profiles of human endogenous retrovirus (HERV)-K and HERV-R Env proteins in various cancers. BMB Rep 2021. [PMID: 33691904 PMCID: PMC8328825 DOI: 10.5483/bmbrep.2021.54.7.246] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The vertebrate genome contains an endogenous retrovirus that has been inherited from the past millions of years. Although approximately 8% of human chromosomal DNA consists of sequences derived from human endogenous retrovirus (HERV) fragments, most of the HERVs are currently inactive and non-infectious due to recombination, deletions, and mutations after insertion into the host genome. Several studies suggested that Human endogenous retroviruses (HERVs) factors are significantly related to certain cancers. However, only limited studies have been conducted to analyze the expression of HERV derived elements at protein levels in certain cancers. Herein, we analyzed the expression profiles of HERV-K envelope (Env) and HERV-R Env proteins in eleven different kinds of cancer tissues. Furthermore, the expression patterns of both protein and correlation with various clinical data in each tissue were analyzed. The expressions of both HERV-K Env and HERV-R Env protein were identified to be significantly high in most of the tumors compared with normal surrounding tissues. Correlations between HERV Env expressions and clinical investigations varied depending on the HERV types and cancers. Overall expression patterns of HERV-K Env and HERV-R Env proteins were different in every individual but a similar pattern of expressions was observed in the same individual. These results demonstrate the expression profiles of HERV-K and HERV-R Env proteins in various cancer tissues and provide a good reference for the association of endogenous retroviral Env proteins in the progression of various cancers. Furthermore, the results elucidate the relationship between HERV-Env expression and the clinical significance of certain cancers.
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Affiliation(s)
- Eun-Ji Ko
- Department of Parasitology and Genetics, Kosin University College of Medicine, Busan 49267, Korea
- Department of Biological Sciences, Pusan National University, Busan 46241, Korea
| | - Kyoung Seob Song
- Department of Physiology, Kosin University College of Medicine, Busan 49267, Korea
| | - Mee Sun Ock
- Department of Parasitology and Genetics, Kosin University College of Medicine, Busan 49267, Korea
| | - Yung Hyun Choi
- Department of Biochemistry, College of Oriental Medicine, Dongeui University, Busan 47227, Korea
| | - Suhkmann Kim
- Department of Chemistry, College of Natural Sciences, Pusan National University, Busan 46241, Korea
| | - Heui-Soo Kim
- Department of Biological Sciences, Pusan National University, Busan 46241, Korea
| | - Hee-Jae Cha
- Department of Parasitology and Genetics, Kosin University College of Medicine, Busan 49267, Korea
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10
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Ko EJ, Song KS, Ock MS, Choi YH, Kim S, Kim HS, Cha HJ. Expression profiles of human endogenous retrovirus (HERV)-K and HERV-R Env proteins in various cancers. BMB Rep 2021; 54:368-373. [PMID: 33691904 PMCID: PMC8328825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/08/2020] [Accepted: 02/21/2021] [Indexed: 04/04/2024] Open
Abstract
The vertebrate genome contains an endogenous retrovirus that has been inherited from the past millions of years. Although approximately 8% of human chromosomal DNA consists of sequences derived from human endogenous retrovirus (HERV) fragments, most of the HERVs are currently inactive and noninfectious due to recombination, deletions, and mutations after insertion into the host genome. Several studies suggested that Human endogenous retroviruses (HERVs) factors are significantly related to certain cancers. However, only limited studies have been conducted to analyze the expression of HERV derived elements at protein levels in certain cancers. Herein, we analyzed the expression profiles of HERV-K envelope (Env) and HERV-R Env proteins in eleven different kinds of cancer tissues. Furthermore, the expression patterns of both protein and correlation with various clinical data in each tissue were analyzed. The expressions of both HERV-K Env and HERV-R Env protein were identified to be significantly high in most of the tumors compared with normal surrounding tissues. Correlations between HERV Env expressions and clinical investigations varied depending on the HERV types and cancers. Overall expression patterns of HERV-K Env and HERV-R Env proteins were different in every individual but a similar pattern of expressions was observed in the same individual. These results demonstrate the expression profiles of HERV-K and HERV-R Env proteins in various cancer tissues and provide a good reference for the association of endogenous retroviral Env proteins in the progression of various cancers. Furthermore, the results elucidate the relationship between HERV-Env expression and the clinical significance of certain cancers. [BMB Reports 2021; 54(7): 368-373].
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Affiliation(s)
- Eun-Ji Ko
- Department of Parasitology and Genetics, Busan 46241, Korea
- Department of Biological Sciences, Busan 46241, Korea
| | - Kyoung Seob Song
- Department of Physiology, Kosin University College of Medicine, Busan 49267, Korea
| | - Mee Sun Ock
- Department of Parasitology and Genetics, Busan 46241, Korea
| | - Yung Hyun Choi
- Department of Biochemistry, College of Oriental Medicine, Dongeui University, Busan 47227, Korea
| | - Suhkmann Kim
- Department of Chemistry, College of Natural Sciences, Pusan National University, Busan 46241, Korea
| | - Heui-Soo Kim
- Department of Biological Sciences, Busan 46241, Korea
| | - Hee-Jae Cha
- Department of Parasitology and Genetics, Busan 46241, Korea
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11
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Shah AH, Gilbert M, Ivan ME, Komotar RJ, Heiss J, Nath A. The role of human endogenous retroviruses in gliomas: from etiological perspectives and therapeutic implications. Neuro Oncol 2021; 23:1647-1655. [PMID: 34120190 DOI: 10.1093/neuonc/noab142] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Accounting for approximately 8% of the human genome, Human Endogenous Retroviruses (HERVs) have been implicated in a variety of cancers including gliomas. In normal cells, tight epigenetic regulation of HERVs prevent aberrant expression; however, in cancer cells, HERVs expression remains pervasive, suggesting a role of HERVs in oncogenic transformation. HERVs may contribute to oncogenesis in several ways including insertional mutagenesis, chromosomal rearrangements, proto-oncogene formation, and maintenance of stemness. On the other hand, recent data has suggested that reversing epigenetic silencing of HERVs may induce robust anti-tumor immune responses, suggesting HERVs' potential therapeutic utility in gliomas. By reversing epigenetic modifications that silence HERVs, DNA methyltransferase and histone deacetylase inhibitors may stimulate a viral-mimicry cascade via HERV-derived dsRNA formation that induce interferon-mediated apoptosis. Leveraging this anti-tumor autoimmune response may be a unique avenue to target certain subsets of epigenetically-dysregulated gliomas. Nevertheless, the role of HERVs in gliomas as either arbitrators of oncogenesis or forerunners of the innate anti-tumor immune response remains unclear. Here, we review the role of HERVs in gliomas, their potential dichotomous function in propagating oncogenesis and stimulating the anti-tumor immune response and identify future directions for research.
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Affiliation(s)
- Ashish H Shah
- Department of Neurological Surgery, University of Miami Miller School of Medicine
| | - Mark Gilbert
- Neuro-oncology Branch, National Cancer Institute, National Institute of Health
| | - Michael E Ivan
- Department of Neurological Surgery, University of Miami Miller School of Medicine
| | - Ricardo J Komotar
- Department of Neurological Surgery, University of Miami Miller School of Medicine
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12
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Díaz-Carballo D, Saka S, Acikelli AH, Homp E, Erwes J, Demmig R, Klein J, Schröer K, Malak S, D'Souza F, Noa-Bolaño A, Menze S, Pano E, Andrioff S, Teipel M, Dammann P, Klein D, Nasreen A, Tannapfel A, Grandi N, Tramontano E, Ochsenfarth C, Strumberg D. Enhanced antitumoral activity of TLR7 agonists via activation of human endogenous retroviruses by HDAC inhibitors. Commun Biol 2021; 4:276. [PMID: 33658617 PMCID: PMC7930250 DOI: 10.1038/s42003-021-01800-3] [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: 04/28/2020] [Accepted: 01/25/2021] [Indexed: 12/18/2022] Open
Abstract
In this work, we are reporting that "Shock and Kill", a therapeutic approach designed to eliminate latent HIV from cell reservoirs, is extrapolatable to cancer therapy. This is based on the observation that malignant cells express a spectrum of human endogenous retroviral elements (HERVs) which can be transcriptionally boosted by HDAC inhibitors. The endoretroviral gene HERV-V2 codes for an envelope protein, which resembles syncytins. It is significantly overexpressed upon exposure to HDAC inhibitors and can be effectively targeted by simultaneous application of TLR7/8 agonists, triggering intrinsic apoptosis. We demonstrated that this synergistic cytotoxic effect was accompanied by the functional disruption of the TLR7/8-NFκB, Akt/PKB, and Ras-MEK-ERK signalling pathways. CRISPR/Cas9 ablation of TLR7 and HERV-V1/V2 curtailed apoptosis significantly, proving the pivotal role of these elements in driving cell death. The effectiveness of this new approach was confirmed in ovarian tumour xenograft studies, revealing a promising avenue for future cancer therapies.
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Affiliation(s)
- David Díaz-Carballo
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany.
| | - Sahitya Saka
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Ali H Acikelli
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Ekaterina Homp
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Julia Erwes
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Rebecca Demmig
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Jacqueline Klein
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Katrin Schröer
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Sascha Malak
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Flevy D'Souza
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Adrien Noa-Bolaño
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Saskia Menze
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Emilio Pano
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Swetlana Andrioff
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Marc Teipel
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
| | - Philip Dammann
- Central Animal Laboratory, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Diana Klein
- Institute of Cell Biology, Cancer Research, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Amber Nasreen
- Visceral Surgery Department, Marien Hospital Herne, Ruhr University Bochum Medical School, Herne, Germany
| | | | - Nicole Grandi
- Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, Monserrato, Italy
| | - Enzo Tramontano
- Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, Monserrato, Italy
| | - Crista Ochsenfarth
- Department of Anesthesia, Intensive Care, Pain and Palliative Medicine, Marien Hospital Herne, Ruhr-University Bochum Medical School, Herne, Germany
| | - Dirk Strumberg
- Ruhr University Bochum, Faculty of Medicine, Department of Haematology and Oncology, Institute of Molecular Oncology and Experimental Therapeutics, Marien Hospital Herne, Herne, Germany
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13
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Kohlrausch FB, Berteli TS, Wang F, Navarro PA, Keefe DL. Control of LINE-1 Expression Maintains Genome Integrity in Germline and Early Embryo Development. Reprod Sci 2021; 29:328-340. [PMID: 33481218 DOI: 10.1007/s43032-021-00461-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 01/06/2021] [Indexed: 11/28/2022]
Abstract
Maintenance of genome integrity in the germline and in preimplantation embryos is crucial for mammalian development. Epigenetic remodeling during primordial germ cell (PGC) and preimplantation embryo development may contribute to genomic instability in these cells, since DNA methylation is an important mechanism to silence retrotransposons. Long interspersed elements 1 (LINE-1 or L1) are the most common autonomous retrotransposons in mammals, corresponding to approximately 17% of the human genome. Retrotransposition events are more frequent in germ cells and in early stages of embryo development compared with somatic cells. It has been shown that L1 activation and expression occurs in germline and is essential for preimplantation development. In this review, we focus on the role of L1 retrotransposon in mouse and human germline and early embryo development and discuss the possible relationship between L1 expression and genomic instability during these stages. Although several studies have addressed L1 expression at different stages of development, the developmental consequences of this expression remain poorly understood. Future research is still needed to highlight the relationship between L1 retrotransposition events and genomic instability during germline and early embryo development.
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Affiliation(s)
- Fabiana B Kohlrausch
- Department of Obstetrics and Gynecology, New York University Langone Medical Center, 462 1st Avenue, New York, NY, 10016, USA.,Departamento de Biologia Geral, Instituto de Biologia, Universidade Federal Fluminense, Niterói, RJ, Brazil
| | - Thalita S Berteli
- Department of Obstetrics and Gynecology, New York University Langone Medical Center, 462 1st Avenue, New York, NY, 10016, USA.,Departamento de Ginecologia e Obstetrícia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Fang Wang
- Department of Obstetrics and Gynecology, New York University Langone Medical Center, 462 1st Avenue, New York, NY, 10016, USA
| | - Paula A Navarro
- Departamento de Ginecologia e Obstetrícia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - David L Keefe
- Department of Obstetrics and Gynecology, New York University Langone Medical Center, 462 1st Avenue, New York, NY, 10016, USA.
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14
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Emamalipour M, Seidi K, Zununi Vahed S, Jahanban-Esfahlan A, Jaymand M, Majdi H, Amoozgar Z, Chitkushev LT, Javaheri T, Jahanban-Esfahlan R, Zare P. Horizontal Gene Transfer: From Evolutionary Flexibility to Disease Progression. Front Cell Dev Biol 2020; 8:229. [PMID: 32509768 PMCID: PMC7248198 DOI: 10.3389/fcell.2020.00229] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 03/17/2020] [Indexed: 12/11/2022] Open
Abstract
Flexibility in the exchange of genetic material takes place between different organisms of the same or different species. This phenomenon is known to play a key role in the genetic, physiological, and ecological performance of the host. Exchange of genetic materials can cause both beneficial and/or adverse biological consequences. Horizontal gene transfer (HGT) or lateral gene transfer (LGT) as a general mechanism leads to biodiversity and biological innovations in nature. HGT mediators are one of the genetic engineering tools used for selective introduction of desired changes in the genome for gene/cell therapy purposes. HGT, however, is crucial in development, emergence, and recurrence of various human-related diseases, such as cancer, genetic-, metabolic-, and neurodegenerative disorders and can negatively affect the therapeutic outcome by promoting resistant forms or disrupting the performance of genome editing toolkits. Because of the importance of HGT and its vital physio- and pathological roles, here the variety of HGT mechanisms are reviewed, ranging from extracellular vesicles (EVs) and nanotubes in prokaryotes to cell-free DNA and apoptotic bodies in eukaryotes. Next, we argue that HGT plays a role both in the development of useful features and in pathological states associated with emerging and recurrent forms of the disease. A better understanding of the different HGT mediators and their genome-altering effects/potentials may pave the way for the development of more effective therapeutic and diagnostic regimes.
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Affiliation(s)
- Melissa Emamalipour
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Khaled Seidi
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | | | - Mehdi Jaymand
- Nano Drug Delivery Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Hasan Majdi
- Department of Medical Nanotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Zohreh Amoozgar
- Edwin L. Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - L T Chitkushev
- Department of Computer Science, Metropolitan College, Boston University, Boston, MA, United States.,Health Informatics Lab, Metropolitan College, Boston University, Boston, MA, United States
| | - Tahereh Javaheri
- Health Informatics Lab, Metropolitan College, Boston University, Boston, MA, United States
| | - Rana Jahanban-Esfahlan
- Department of Medical Biotechnology, School of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Peyman Zare
- Faculty of Medicine, Cardinal Stefan Wyszyński University in Warsaw, Warsaw, Poland.,Dioscuri Center of Chromatin Biology and Epigenomics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
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15
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Attig J, Young GR, Hosie L, Perkins D, Encheva-Yokoya V, Stoye JP, Snijders AP, Ternette N, Kassiotis G. LTR retroelement expansion of the human cancer transcriptome and immunopeptidome revealed by de novo transcript assembly. Genome Res 2019; 29:1578-1590. [PMID: 31537638 PMCID: PMC6771403 DOI: 10.1101/gr.248922.119] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 08/21/2019] [Indexed: 12/30/2022]
Abstract
Dysregulated endogenous retroelements (EREs) are increasingly implicated in the initiation, progression, and immune surveillance of human cancer. However, incomplete knowledge of ERE activity limits mechanistic studies. By using pan-cancer de novo transcript assembly, we uncover the extent and complexity of ERE transcription. The current assembly doubled the number of previously annotated transcripts overlapping with long-terminal repeat (LTR) elements, several thousand of which were expressed specifically in one or a few related cancer types. Exemplified in melanoma, LTR-overlapping transcripts were highly predictable, disease prognostic, and closely linked with molecularly defined subtypes. They further showed the potential to affect disease-relevant genes, as well as produce novel cancer-specific antigenic peptides. This extended view of LTR elements provides the framework for functional validation of affected genes and targets for cancer immunotherapy.
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Affiliation(s)
- Jan Attig
- Retroviral Immunology, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - George R. Young
- Retrovirus-Host Interactions, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Louise Hosie
- Retroviral Immunology, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - David Perkins
- Mass Spectrometry Proteomics, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Vesela Encheva-Yokoya
- Mass Spectrometry Proteomics, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Jonathan P. Stoye
- Retrovirus-Host Interactions, The Francis Crick Institute, London NW1 1AT, United Kingdom;,Department of Medicine, Faculty of Medicine, Imperial College, London W2 1PG, United Kingdom
| | - Ambrosius P. Snijders
- Mass Spectrometry Proteomics, The Francis Crick Institute, London NW1 1AT, United Kingdom
| | - Nicola Ternette
- The Jenner Institute, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - George Kassiotis
- Retroviral Immunology, The Francis Crick Institute, London NW1 1AT, United Kingdom;,Department of Medicine, Faculty of Medicine, Imperial College, London W2 1PG, United Kingdom
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16
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Bergallo M, Mareschi K, Montanari P, Calvi C, Berger M, Bini I, Daprà V, Galliano I, Fagioli F. Human endogenous retrovirus, HERV-P and HERV-R in pediatric leukemia patients. J Hematop 2019. [DOI: 10.1007/s12308-019-00352-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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17
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Li W, Lin L, Malhotra R, Yang L, Acharya R, Poss M. A computational framework to assess genome-wide distribution of polymorphic human endogenous retrovirus-K In human populations. PLoS Comput Biol 2019; 15:e1006564. [PMID: 30921327 PMCID: PMC6456218 DOI: 10.1371/journal.pcbi.1006564] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 04/09/2019] [Accepted: 03/05/2019] [Indexed: 12/11/2022] Open
Abstract
Human Endogenous Retrovirus type K (HERV-K) is the only HERV known to be insertionally polymorphic; not all individuals have a retrovirus at a specific genomic location. It is possible that HERV-Ks contribute to human disease because people differ in both number and genomic location of these retroviruses. Indeed viral transcripts, proteins, and antibody against HERV-K are detected in cancers, auto-immune, and neurodegenerative diseases. However, attempts to link a polymorphic HERV-K with any disease have been frustrated in part because population prevalence of HERV-K provirus at each polymorphic site is lacking and it is challenging to identify closely related elements such as HERV-K from short read sequence data. We present an integrated and computationally robust approach that uses whole genome short read data to determine the occupation status at all sites reported to contain a HERV-K provirus. Our method estimates the proportion of fixed length genomic sequence (k-mers) from whole genome sequence data matching a reference set of k-mers unique to each HERV-K locus and applies mixture model-based clustering of these values to account for low depth sequence data. Our analysis of 1000 Genomes Project Data (KGP) reveals numerous differences among the five KGP super-populations in the prevalence of individual and co-occurring HERV-K proviruses; we provide a visualization tool to easily depict the proportion of the KGP populations with any combination of polymorphic HERV-K provirus. Further, because HERV-K is insertionally polymorphic, the genome burden of known polymorphic HERV-K is variable in humans; this burden is lowest in East Asian (EAS) individuals. Our study identifies population-specific sequence variation for HERV-K proviruses at several loci. We expect these resources will advance research on HERV-K contributions to human diseases. Human Endogenous Retrovirus type K (HERV-K) is the youngest of retrovirus families in the human genome and is the only group of endogenous retroviruses that has polymorphic members; a locus containing a HERV-K can be occupied in one individual but empty in others. HERV-Ks could contribute to disease risk or pathogenesis but linking one of the known polymorphic HERV-K to a specific disease has been difficult. We develop an easy to use method that reveals the considerable variation existing among global populations in the prevalence of individual and co-occurring polymorphic HERV-K, and in the number of HERV-K that any individual has in their genome. Our study provides a reference of diversity for the currently known polymorphic HERV-K in global populations and tools needed to determine the profile of all known polymorphic HERV-K in the genome of any patient population.
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Affiliation(s)
- Weiling Li
- The School of Electrical Engineering and Computer Science, The Pennsylvania State University, University Park, PA, United States of America
| | - Lin Lin
- Department of Statistics, The Pennsylvania State University, University Park, PA, United States of America
| | - Raunaq Malhotra
- The School of Electrical Engineering and Computer Science, The Pennsylvania State University, University Park, PA, United States of America
| | - Lei Yang
- Department of Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Raj Acharya
- The School of Electrical Engineering and Computer Science, The Pennsylvania State University, University Park, PA, United States of America
- School of Informatics, Computing and Engineering, Indiana University, Bloomington, IN, United States of America
| | - Mary Poss
- Department of Biology, The Pennsylvania State University, University Park, PA, United States of America
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, United States of America
- * E-mail:
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18
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Zhang M, Liang JQ, Zheng S. Expressional activation and functional roles of human endogenous retroviruses in cancers. Rev Med Virol 2019; 29:e2025. [PMID: 30614117 PMCID: PMC6590502 DOI: 10.1002/rmv.2025] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 10/26/2018] [Accepted: 11/05/2018] [Indexed: 12/26/2022]
Abstract
Human endogenous retroviruses (HERVs) are widely believed to be remnants of ancestral germ line infections by exogenous retroviruses. Although HERVs are deemed as “nonfunctional DNAs” due to loss of most of their viral protein coding capacity during evolution as part of the human genome, cumulative evidences are showing the expressional activation and potential roles of HERVs in diseases especially cancers. Work by other researchers and us has observed the dysregulation of HERVs in cancers, identified new HERV‐related genes, and revealed their potential importance in cancer development. Here, we summarized the current knowledge on the mechanisms of the expressional activation and functional roles of HERVs, with a focus on the H family HERV (HERV‐H), in carcinogenesis. HERV expression is regulated by external chemical or physical substances and exogenous virus infection, as well as host factors such as epigenetic DNA methylation, transcription factors, cytokines, and small RNAs. Diverse roles of HERVs have been proposed by acting in the forms of noncoding RNAs, proteins, and transcriptional regulators during carcinogenesis. However, much remains to be learnt about the contributions of HERVs to human cancers. More investigation is warranted to elucidate the functions of these “fossil remnants” yet important viral DNAs in the human genome.
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Affiliation(s)
- Mengwen Zhang
- The Department of Plastic and Reconstructive Surgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Cancer Institute, Second Affiliated Hospital, and Ministry of Education Key Laboratory of Cancer Prevention and Intervention, Zhejiang University School of Medicine, Hangzhou, China
| | - Jessie Qiaoyi Liang
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong, China
| | - Shu Zheng
- Cancer Institute, Second Affiliated Hospital, and Ministry of Education Key Laboratory of Cancer Prevention and Intervention, Zhejiang University School of Medicine, Hangzhou, China.,The Department of surgical oncology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
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19
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Matteucci C, Balestrieri E, Argaw-Denboba A, Sinibaldi-Vallebona P. Human endogenous retroviruses role in cancer cell stemness. Semin Cancer Biol 2018; 53:17-30. [PMID: 30317035 DOI: 10.1016/j.semcancer.2018.10.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 09/30/2018] [Accepted: 10/05/2018] [Indexed: 12/18/2022]
Abstract
Cancer incidence and mortality, metastasis, drug resistance and recurrence are still the critical issues of oncological diseases. In this scenario, increasing scientific evidences demonstrate that the activation of human endogenous retroviruses (HERVs) is involved in the aggressiveness of tumors such as melanoma, breast, germ cell, renal, ovarian, liver and haematological cancers. In their dynamic regulation, HERVs have also proved to be important determinants of pluripotency in human embryonic stem cells (ESC) and of the reprogramming process of induced pluripotent stem cells (iPSCs). In many types of tumors, essential characteristics of aggressiveness have been associated with the achievement of stemness features, often accompanied with the identification of defined subpopulations, termed cancer stem cells (CSCs), which possess stem cell-like properties and sustain tumorigenesis. Indeed, CSCs show high self-renewal capacity with a peculiar potential in tumor initiation, progression, metastasis, heterogeneity, recurrence, radiotherapy and drug resistance. However, HERVs role in CSCs biology is still not fully elucidated. In this regard, CD133 is a widely recognized marker of CSCs, and our group demonstrated, for the first time, the requirement of HERV-K activation to expand and maintain a CD133+ melanoma cell subpopulation with stemness features in response to microenvironmental modifications. The review will discuss HERVs expression as cancer hallmark, with particular focus on their role in the regulation of cancer stemness features and the potential involvement as targets for therapy.
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Affiliation(s)
- Claudia Matteucci
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier, 1, 00133, Rome, Italy.
| | - Emanuela Balestrieri
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier, 1, 00133, Rome, Italy
| | - Ayele Argaw-Denboba
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier, 1, 00133, Rome, Italy; European Molecular Biology Laboratory (EMBL), Adriano Buzzati-Traverso Campus, Monterotondo, Rome, Italy
| | - Paola Sinibaldi-Vallebona
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier, 1, 00133, Rome, Italy; Institute of Translational Pharmacology, National Research Council, Via Fosso del Cavaliere, 100, 00133, Rome, Italy
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20
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Balestrieri E, Argaw-Denboba A, Gambacurta A, Cipriani C, Bei R, Serafino A, Sinibaldi-Vallebona P, Matteucci C. Human Endogenous Retrovirus K in the Crosstalk Between Cancer Cells Microenvironment and Plasticity: A New Perspective for Combination Therapy. Front Microbiol 2018; 9:1448. [PMID: 30013542 PMCID: PMC6036167 DOI: 10.3389/fmicb.2018.01448] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/11/2018] [Indexed: 12/24/2022] Open
Abstract
Abnormal activation of human endogenous retroviruses (HERVs) has been associated with several diseases such as cancer, autoimmunity, and neurological disorders. In particular, in cancer HERV activity and expression have been specifically associated with tumor aggressiveness and patient outcomes. Cancer cell aggressiveness is intimately linked to the acquisition of peculiar plasticity and heterogeneity based on cell stemness features, as well as on the crosstalk between cancer cells and the microenvironment. The latter is a driving factor in the acquisition of aggressive phenotypes, associated with metastasis and resistance to conventional cancer therapies. Remarkably, in different cell types and stages of development, HERV expression is mainly regulated by epigenetic mechanisms and is subjected to a very precise temporal and spatial regulation according to the surrounding microenvironment. Focusing on our research experience with HERV-K involvement in the aggressiveness and plasticity of melanoma cells, this perspective aims to highlight the role of HERV-K in the crosstalk between cancer cells and the tumor microenvironment. The implications for a combination therapy targeted at HERVs with standard approaches are discussed.
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Affiliation(s)
- Emanuela Balestrieri
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy
| | - Ayele Argaw-Denboba
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy
| | - Alessandra Gambacurta
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy
| | - Chiara Cipriani
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy
| | - Roberto Bei
- Department of Clinical Sciences and Translational Medicine, University of Rome "Tor Vergata", Rome, Italy
| | - Annalucia Serafino
- Institute of Translational Pharmacology, National Research Council, Rome, Italy
| | - Paola Sinibaldi-Vallebona
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy.,Institute of Translational Pharmacology, National Research Council, Rome, Italy
| | - Claudia Matteucci
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy
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21
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Nguyen NPD, Deshpande V, Luebeck J, Mischel PS, Bafna V. ViFi: accurate detection of viral integration and mRNA fusion reveals indiscriminate and unregulated transcription in proximal genomic regions in cervical cancer. Nucleic Acids Res 2018; 46:3309-3325. [PMID: 29579309 PMCID: PMC6283451 DOI: 10.1093/nar/gky180] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 02/12/2018] [Accepted: 03/05/2018] [Indexed: 12/20/2022] Open
Abstract
The integration of viral sequences into the host genome is an important driver of tumorigenesis in many viral mediated cancers, notably cervical cancer and hepatocellular carcinoma. We present ViFi, a computational method that combines phylogenetic methods with reference-based read mapping to detect viral integrations. In contrast with read-based reference mapping approaches, ViFi is faster, and shows high precision and sensitivity on both simulated and biological data, even when the integrated virus is a novel strain or highly mutated. We applied ViFi to matched genomic and mRNA data from 68 cervical cancer samples from TCGA and found high concordance between the two. Surprisingly, viral integration resulted in a dramatic transcriptional upregulation in all proximal elements, including LINEs and LTRs that are not normally transcribed. This upregulation is highly correlated with the presence of a viral gene fused with a downstream human element. Moreover, genomic rearrangements suggest the formation of apparent circular extrachromosomal (ecDNA) human-viral structures. Our results suggest the presence of apparent small circular fusion viral/human ecDNA, which correlates with indiscriminate and unregulated expression of proximal genomic elements, potentially contributing to the pathogenesis of HPV-associated cervical cancers. ViFi is available at https://github.com/namphuon/ViFi.
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Affiliation(s)
- Nam-phuong D Nguyen
- Computer Science and Engineering, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA
| | - Viraj Deshpande
- Computer Science and Engineering, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA
| | - Jens Luebeck
- Bioinformatics and Systems Biology Program, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA
| | - Paul S Mischel
- Ludwig Institute for Cancer Research, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA
- Department of Pathology, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA
- Moores Cancer Center, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA
| | - Vineet Bafna
- Computer Science and Engineering, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA
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22
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Kassiotis G, Stoye JP. Making a virtue of necessity: the pleiotropic role of human endogenous retroviruses in cancer. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0277. [PMID: 28893944 PMCID: PMC5597744 DOI: 10.1098/rstb.2016.0277] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/09/2017] [Indexed: 12/18/2022] Open
Abstract
Like all other mammals, humans harbour an astonishing number of endogenous retroviruses (ERVs), as well as other retroelements, embedded in their genome. These remnants of ancestral germline infection with distinct exogenous retroviruses display various degrees of open reading frame integrity and replication capability. Modern day exogenous retroviruses, as well as the infectious predecessors of ERVs, are demonstrably oncogenic. Further, replication-competent ERVs continue to cause cancers in many other species of mammal. Moreover, human cancers are characterized by transcriptional activation of human endogenous retroviruses (HERVs). These observations conspire to incriminate HERVs as causative agents of human cancer. However, exhaustive investigation of cancer genomes suggests that HERVs have entirely lost the ability for re-infection and thus the potential for insertional mutagenic activity. Although there may be non-insertional mechanisms by which HERVs contribute to cancer development, recent evidence also uncovers potent anti-tumour activities exerted by HERV replication intermediates or protein products. On balance, it appears that HERVs, despite their oncogenic past, now represent potential targets for immune-mediated anti-tumour mechanisms. This article is part of the themed issue ‘Human oncogenic viruses’.
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Affiliation(s)
- George Kassiotis
- Retroviral Immunology, The Francis Crick Institute, London, UK .,Department of Medicine, Faculty of Medicine, Imperial College London, London, UK
| | - Jonathan P Stoye
- Retrovirus-Host Interactions, The Francis Crick Institute, London, UK .,Department of Medicine, Faculty of Medicine, Imperial College London, London, UK
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23
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Abstract
Krüppel-associated box domain zinc finger proteins (KRAB-ZFPs) are the largest family of transcriptional regulators in higher vertebrates. Characterized by an N-terminal KRAB domain and a C-terminal array of DNA-binding zinc fingers, they participate, together with their co-factor KAP1 (also known as TRIM28), in repression of sequences derived from transposable elements (TEs). Until recently, KRAB-ZFP/KAP1-mediated repression of TEs was thought to lead to irreversible silencing, and the evolutionary selection of KRAB-ZFPs was considered to be just the host component of an arms race against TEs. However, recent advances indicate that KRAB-ZFPs and their TE targets also partner up to establish species-specific regulatory networks. Here, we provide an overview of the KRAB-ZFP gene family, highlighting how its evolutionary history is linked to that of TEs, and how KRAB-ZFPs influence multiple aspects of development and physiology.
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Affiliation(s)
- Gabriela Ecco
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Station19, 1015 Lausanne, Switzerland
| | - Michael Imbeault
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Station19, 1015 Lausanne, Switzerland
| | - Didier Trono
- School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Station19, 1015 Lausanne, Switzerland
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Human leukemia antigen-A*0201-restricted epitopes of human endogenous retrovirus W family envelope (HERV-W env) induce strong cytotoxic T lymphocyte responses. Virol Sin 2017; 32:280-289. [PMID: 28840564 DOI: 10.1007/s12250-017-3984-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 07/20/2017] [Indexed: 12/29/2022] Open
Abstract
Human endogenous retrovirus W family (HERV-W) envelope (env) has been reported to be related to several human diseases, including autoimmune disorders, and it could activate innate immunity. However, there are no reports investigating whether human leukemia antigen (HLA)-A*0201+ restriction is involved in the immune response caused by HERV-W env in neuropsychiatric diseases. In the present study, HERV-W env-derived epitopes presented by HLA-A*0201 are described with the potential for use in adoptive immunotherapy. Five peptides displaying HLA-A*0201-binding motifs were predicted using SYFEPITHI and BIMAS, and synthesized. A CCK-8 assay showed peptides W, Q and T promoted lymphocyte proliferation. Stimulation of peripheral blood mononuclear cells from HLA-A*0201+ donors with each of these peptides induced peptide-specific CD8+ T cells. High numbers of IFN-γ-secreting T cells were also detectable after several weekly stimulations with W, Q and T. Besides lysis of HERV-W env-loaded target cells, specific apoptosis was also observed. These data demonstrate that human T cells can be sensitized toward HERV-W env peptides (W, Q and T) and, moreover, pose a high killing potential toward HERV-W env-expressing U251 cells. In conclusion, peptides W Q and T, which are HERV-W env antigenic epitopes, have both antigenicity and immunogenicity, and can cause strong T cell immune responses. Our data strengthen the view that HERV-W env should be considered as an autoantigen that can induce autoimmunity in neuropsychiatric diseases, such as multiple sclerosis and schizophrenia. These data might provide an experimental foundation for a HERV-W env peptide vaccine and new insight into the treatment of neuropsychiatric diseases.
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Lock FE, Babaian A, Zhang Y, Gagnier L, Kuah S, Weberling A, Karimi MM, Mager DL. A novel isoform of IL-33 revealed by screening for transposable element promoted genes in human colorectal cancer. PLoS One 2017; 12:e0180659. [PMID: 28715472 PMCID: PMC5513427 DOI: 10.1371/journal.pone.0180659] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/19/2017] [Indexed: 02/06/2023] Open
Abstract
Remnants of ancient transposable elements (TEs) are abundant in mammalian genomes. These sequences contain multiple regulatory motifs and hence are capable of influencing expression of host genes. TEs are known to be released from epigenetic repression and can become transcriptionally active in cancer. Such activation could also lead to lineage-inappropriate activation of oncogenes, as previously described in lymphomas. However, there are few reports of this mechanism occurring in non-blood cancers. Here, we re-analyzed whole transcriptome data from a large cohort of patients with colon cancer, compared to matched normal colon control samples, to detect genes or transcripts ectopically expressed through activation of TE promoters. Among many such transcripts, we identified six where the affected gene has described role in cancer and where the TE-driven gene mRNA is expressed in primary colon cancer, but not normal matched tissue, and confirmed expression in colon cancer-derived cell lines. We further characterized a TE-gene chimeric transcript involving the Interleukin 33 (IL-33) gene (termed LTR-IL-33), that is ectopically expressed in a subset of colon cancer samples through the use of an endogenous retroviral long terminal repeat (LTR) promoter of the MSTD family. The LTR-IL-33 chimeric transcript encodes a novel shorter isoform of the protein, which is missing the initial N-terminus (including many conserved residues) of Native IL-33. In vitro studies showed that LTR-IL-33 expression is required for optimal CRC cell line growth as 3D colonospheres. Taken together, these data demonstrate the significance of TEs as regulators of aberrant gene expression in colon cancer.
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Affiliation(s)
- Frances E. Lock
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Artem Babaian
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Ying Zhang
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Liane Gagnier
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Sabrina Kuah
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada
| | - Antonia Weberling
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada
| | - Mohammad M. Karimi
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- Département de Génomique Fonctionnelle et Cancer, Institut de Génétique et Biologie Moléculaire et Cellulaire (IGBMC)/Université de Strasbourg/CNRS/INSERM, France
| | - Dixie L. Mager
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
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Li M, Radvanyi L, Yin B, Rycaj K, Li J, Chivukula R, Lin K, Lu Y, Shen J, Chang DZ, Li D, Johanning GL, Wang-Johanning F. Downregulation of Human Endogenous Retrovirus Type K (HERV-K) Viral env RNA in Pancreatic Cancer Cells Decreases Cell Proliferation and Tumor Growth. Clin Cancer Res 2017; 23:5892-5911. [PMID: 28679769 DOI: 10.1158/1078-0432.ccr-17-0001] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 05/09/2017] [Accepted: 06/29/2017] [Indexed: 12/23/2022]
Abstract
Purpose: We investigated the role of the human endogenous retrovirus type K (HERV-K) envelope (env) gene in pancreatic cancer.Experimental Design: shRNA was employed to knockdown (KD) the expression of HERV-K in pancreatic cancer cells.Results: HERV-K env expression was detected in seven pancreatic cancer cell lines and in 80% of pancreatic cancer patient biopsies, but not in two normal pancreatic cell lines or uninvolved normal tissues. A new HERV-K splice variant was discovered in several pancreatic cancer cell lines. Reverse transcriptase activity and virus-like particles were observed in culture media supernatant obtained from Panc-1 and Panc-2 cells. HERV-K viral RNA levels and anti-HERV-K antibody titers were significantly higher in pancreatic cancer patient sera (N = 106) than in normal donor sera (N = 40). Importantly, the in vitro and in vivo growth rates of three pancreatic cancer cell lines were significantly reduced after HERV-K KD by shRNA targeting HERV-K env, and there was reduced metastasis to lung after treatment. RNA-Seq results revealed changes in gene expression after HERV-K env KD, including RAS and TP53. Furthermore, downregulation of HERV-K Env protein expression by shRNA also resulted in decreased expression of RAS, p-ERK, p-RSK, and p-AKT in several pancreatic cancer cells or tumors.Conclusions: These results demonstrate that HERV-K influences signal transduction via the RAS-ERK-RSK pathway in pancreatic cancer. Our data highlight the potentially important role of HERV-K in tumorigenesis and progression of pancreatic cancer, and indicate that HERV-K viral proteins may be attractive biomarkers and/or tumor-associated antigens, as well as potentially useful targets for detection, diagnosis, and immunotherapy of pancreatic cancer. Clin Cancer Res; 23(19); 5892-911. ©2017 AACR.
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Affiliation(s)
- Ming Li
- Viral Oncology Program, Center for Cancer and Metabolism, SRI International, Menlo Park, California
| | - Laszlo Radvanyi
- EMD Serono Research and Development Institute, Billerica, Massachusetts
| | - Bingnan Yin
- Department of Inflammation and Epigenetics, Methodist Research Institute, Houston, Texas
| | | | - Jia Li
- Viral Oncology Program, Center for Cancer and Metabolism, SRI International, Menlo Park, California
| | - Raghavender Chivukula
- Viral Oncology Program, Center for Cancer and Metabolism, SRI International, Menlo Park, California
| | - Kevin Lin
- Department of Epigenetics and Molecular Carcinogenesis, Science Park, the University of Texas MD Anderson Cancer Center, Smithville, Texas
| | - Yue Lu
- Department of Epigenetics and Molecular Carcinogenesis, Science Park, the University of Texas MD Anderson Cancer Center, Smithville, Texas
| | - JianJun Shen
- Department of Epigenetics and Molecular Carcinogenesis, Science Park, the University of Texas MD Anderson Cancer Center, Smithville, Texas
| | - David Z Chang
- Virginia Oncology Associates, Newport News, Virginia
| | - Donghui Li
- Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Gary L Johanning
- Viral Oncology Program, Center for Cancer and Metabolism, SRI International, Menlo Park, California
| | - Feng Wang-Johanning
- Viral Oncology Program, Center for Cancer and Metabolism, SRI International, Menlo Park, California.
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Babaian A, Mager DL. Endogenous retroviral promoter exaptation in human cancer. Mob DNA 2016; 7:24. [PMID: 27980689 PMCID: PMC5134097 DOI: 10.1186/s13100-016-0080-x] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 11/11/2016] [Indexed: 12/13/2022] Open
Abstract
Cancer arises from a series of genetic and epigenetic changes, which result in abnormal expression or mutational activation of oncogenes, as well as suppression/inactivation of tumor suppressor genes. Aberrant expression of coding genes or long non-coding RNAs (lncRNAs) with oncogenic properties can be caused by translocations, gene amplifications, point mutations or other less characterized mechanisms. One such mechanism is the inappropriate usage of normally dormant, tissue-restricted or cryptic enhancers or promoters that serve to drive oncogenic gene expression. Dispersed across the human genome, endogenous retroviruses (ERVs) provide an enormous reservoir of autonomous gene regulatory modules, some of which have been co-opted by the host during evolution to play important roles in normal regulation of genes and gene networks. This review focuses on the “dark side” of such ERV regulatory capacity. Specifically, we discuss a growing number of examples of normally dormant or epigenetically repressed ERVs that have been harnessed to drive oncogenes in human cancer, a process we term onco-exaptation, and we propose potential mechanisms that may underlie this phenomenon.
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Affiliation(s)
- Artem Babaian
- Terry Fox Laboratory, British Columbia Cancer Agency, 675 West 10th Avenue, Vancouver, BC V5Z1L3 Canada ; Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada
| | - Dixie L Mager
- Terry Fox Laboratory, British Columbia Cancer Agency, 675 West 10th Avenue, Vancouver, BC V5Z1L3 Canada ; Department of Medical Genetics, University of British Columbia, Vancouver, BC Canada
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Bray S, Turnbull M, Hebert S, Douville RN. Insight into the ERVK Integrase - Propensity for DNA Damage. Front Microbiol 2016; 7:1941. [PMID: 27990140 PMCID: PMC5131560 DOI: 10.3389/fmicb.2016.01941] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 11/18/2016] [Indexed: 12/18/2022] Open
Abstract
Retroviruses create permanently integrated proviruses that exist in the host genome. Retroviral genomes encode for functionally conserved gag, pro, pol, and env regions, as well as integrase (IN), which is required for retroviral integration. IN mediates viral genome insertion through 3′ end processing of the viral DNA and the strand transfer reaction. This process requires the formation of a pre-integration complex, comprised of IN, viral DNA, and cellular proteins. Viral insertion causes DNA damage, leading to the requirement of host DNA repair mechanisms. Therefore, a failure of DNA repair pathways may result in genomic instability and potentially cause host cell death. Considering the numerous human diseases associated with genomic instability, the endogenous retrovirus-K (ERVK) IN should be considered as a putative contributor to DNA damage in human cells. Future research and drug discovery should focus on ERVK IN activity and its role in human conditions, such as neurological disease and cancers.
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Affiliation(s)
- Samantha Bray
- Douville Lab, Department of Biology, University of Winnipeg, Winnipeg MB, Canada
| | - Matthew Turnbull
- Douville Lab, Department of Biology, University of Winnipeg, Winnipeg MB, Canada
| | - Sherry Hebert
- Douville Lab, Department of Biology, University of Winnipeg, Winnipeg MB, Canada
| | - Renée N Douville
- Douville Lab, Department of Biology, University of Winnipeg, WinnipegMB, Canada; Department of Immunology, University of Manitoba, WinnipegMB, Canada
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Kozlov AP. Expression of evolutionarily novel genes in tumors. Infect Agent Cancer 2016; 11:34. [PMID: 27437030 PMCID: PMC4949931 DOI: 10.1186/s13027-016-0077-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 05/18/2016] [Indexed: 01/29/2023] Open
Abstract
The evolutionarily novel genes originated through different molecular mechanisms are expressed in tumors. Sometimes the expression of evolutionarily novel genes in tumors is highly specific. Moreover positive selection of many human tumor-related genes in primate lineage suggests their involvement in the origin of new functions beneficial to organisms. It is suggested to consider the expression of evolutionarily young or novel genes in tumors as a new biological phenomenon, a phenomenon of TSEEN (tumor specifically expressed, evolutionarily novel) genes.
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Affiliation(s)
- A. P. Kozlov
- The Biomedical Center and Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
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Abstract
Over 40% of mammalian genomes comprise the products of reverse transcription. Among such retrotransposed sequences are those characterized by the presence of long terminal repeats (LTRs), including the endogenous retroviruses (ERVs), which are inherited genetic elements closely resembling the proviruses formed following exogenous retrovirus infection. Sequences derived from ERVs make up at least 8 to 10% of the human and mouse genomes and range from ancient sequences that predate mammalian divergence to elements that are currently still active. In this chapter we describe the discovery, classification and origins of ERVs in mammals and consider cellular mechanisms that have evolved to control their expression. We also discuss the negative effects of ERVs as agents of genetic disease and cancer and review examples of ERV protein domestication to serve host functions, as in placental development. Finally, we address growing evidence that the gene regulatory potential of ERV LTRs has been exploited multiple times during evolution to regulate genes and gene networks. Thus, although recently endogenized retroviral elements are often pathogenic, those that survive the forces of negative selection become neutral components of the host genome or can be harnessed to serve beneficial roles.
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Vilahur N, Vahter M, Broberg K. The Epigenetic Effects of Prenatal Cadmium Exposure. Curr Environ Health Rep 2016; 2:195-203. [PMID: 25960943 PMCID: PMC4417128 DOI: 10.1007/s40572-015-0049-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Prenatal exposure to the highly toxic and common pollutant cadmium has been associated with adverse effects on child health and development. However, the underlying biological mechanisms of cadmium toxicity remain partially unsolved. Epigenetic disruption due to early cadmium exposure has gained attention as a plausible mode of action, since epigenetic signatures respond to environmental stimuli and the fetus undergoes drastic epigenomic rearrangements during embryogenesis. In the current review, we provide a critical examination of the literature addressing prenatal cadmium exposure and epigenetic effects in human, animal, and in vitro studies. We conducted a PubMed search and obtained eight recent studies addressing this topic, focusing almost exclusively on DNA methylation. These studies provide evidence that cadmium alters epigenetic signatures in the DNA of the placenta and of the newborns, and some studies indicated marked sexual differences for cadmium-related DNA methylation changes. Associations between early cadmium exposure and DNA methylation might reflect interference with de novo DNA methyltransferases. More studies, especially those including environmentally relevant doses, are needed to confirm the toxicoepigenomic effects of prenatal cadmium exposure and how that relates to the observed health effects of cadmium in childhood and later life.
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Affiliation(s)
- Nadia Vilahur
- Institute of Environmental Medicine, Unit of Metals and Health, Karolinska Institutet, Nobels väg 13, Box 210, SE-171 77 Stockholm, Sweden
| | - Marie Vahter
- Institute of Environmental Medicine, Unit of Metals and Health, Karolinska Institutet, Nobels väg 13, Box 210, SE-171 77 Stockholm, Sweden
| | - Karin Broberg
- Institute of Environmental Medicine, Unit of Metals and Health, Karolinska Institutet, Nobels väg 13, Box 210, SE-171 77 Stockholm, Sweden
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Christensen T. Human endogenous retroviruses in neurologic disease. APMIS 2016; 124:116-26. [DOI: 10.1111/apm.12486] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 10/26/2015] [Indexed: 12/13/2022]
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MSRV envelope protein is a potent, endogenous and pathogenic agonist of human toll-like receptor 4: Relevance of GNbAC1 in multiple sclerosis treatment. J Neuroimmunol 2015; 291:29-38. [PMID: 26857492 DOI: 10.1016/j.jneuroim.2015.12.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 12/03/2015] [Accepted: 12/10/2015] [Indexed: 02/07/2023]
Abstract
Multiple sclerosis associated retrovirus envelope protein (MSRV-Env) was repeatedly detected in brain lesions and blood of multiple sclerosis (MS) patients. We performed the first pharmacological characterisation of MSRV-Env on recombinant and native human TLR4. MSRV-Env is a full and highly potent TLR4 agonist of endogenous origin. MSRV-Env induces TLR4-dependent pro-inflammatory stimulation of immune cells in vitro and in vivo, and impairs oligodendrocytes precursor cells differentiation to myelinating oligodendrocytes. MSRV-Env may play a role in chronic inflammation and impaired remyelination in MS. GNbAC1, a selective monoclonal antibody, antagonizes MSRV-Env pathogenic effects and represents an innovative therapeutic approach of MS.
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Marttila S, Kananen L, Häyrynen S, Jylhävä J, Nevalainen T, Hervonen A, Jylhä M, Nykter M, Hurme M. Ageing-associated changes in the human DNA methylome: genomic locations and effects on gene expression. BMC Genomics 2015; 16:179. [PMID: 25888029 PMCID: PMC4404609 DOI: 10.1186/s12864-015-1381-z] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 02/21/2015] [Indexed: 01/11/2023] Open
Abstract
Background Changes in DNA methylation are among the mechanisms contributing to the ageing process. We sought to identify ageing-associated DNA methylation changes at single-CpG-site resolution in blood leukocytes and to ensure that the observed changes were not due to differences in the proportions of leukocytes. The association between DNA methylation changes and gene expression levels was also investigated in the same individuals. Results We identified 8540 high-confidence ageing-associated CpG sites, 46% of which were hypermethylated in nonagenarians. The hypermethylation-associated genes belonged to a common category: they were predicted to be regulated by a common group of transcription factors and were enriched in a related set of GO terms and canonical pathways. Conversely, for the hypomethylation-associated genes only a limited set of GO terms and canonical pathways were identified. Among the 8540 CpG sites associated with ageing, methylation level of 377 sites was also associated with gene expression levels. These genes were enriched in GO terms and canonical pathways associated with immune system functions, particularly phagocytosis. Conclusions We find that certain ageing-associated immune-system impairments may be mediated via changes in DNA methylation. The results also imply that ageing-associated hypo- and hypermethylation are distinct processes: hypermethylation could be caused by programmed changes, whereas hypomethylation could be the result of environmental and stochastic processes. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1381-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Saara Marttila
- Department of Microbiology and Immunology, School of Medicine, University of Tampere, Tampere, Finland. .,Gerontology Research Center, Tampere, Finland.
| | - Laura Kananen
- Department of Microbiology and Immunology, School of Medicine, University of Tampere, Tampere, Finland. .,Gerontology Research Center, Tampere, Finland.
| | - Sergei Häyrynen
- Institute of Biosciences and Medical Technology, University of Tampere, Tampere, Finland.
| | - Juulia Jylhävä
- Department of Microbiology and Immunology, School of Medicine, University of Tampere, Tampere, Finland. .,Gerontology Research Center, Tampere, Finland.
| | - Tapio Nevalainen
- Department of Microbiology and Immunology, School of Medicine, University of Tampere, Tampere, Finland. .,Gerontology Research Center, Tampere, Finland.
| | - Antti Hervonen
- Gerontology Research Center, Tampere, Finland. .,School of Health Sciences, University of Tampere, Tampere, Finland.
| | - Marja Jylhä
- Gerontology Research Center, Tampere, Finland. .,School of Health Sciences, University of Tampere, Tampere, Finland.
| | - Matti Nykter
- Institute of Biosciences and Medical Technology, University of Tampere, Tampere, Finland.
| | - Mikko Hurme
- Department of Microbiology and Immunology, School of Medicine, University of Tampere, Tampere, Finland. .,Gerontology Research Center, Tampere, Finland. .,Fimlab Laboratories, Tampere, Finland.
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Bae JH, Eo J, Kim TO, Yi JM. Biological changes of transposable elements by radiation: recent progress. Genes Genomics 2014. [DOI: 10.1007/s13258-014-0256-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Vilahur N, Bustamante M, Byun HM, Fernandez MF, Santa Marina L, Basterrechea M, Ballester F, Murcia M, Tardón A, Fernández-Somoano A, Estivill X, Olea N, Sunyer J, Baccarelli AA. Prenatal exposure to mixtures of xenoestrogens and repetitive element DNA methylation changes in human placenta. ENVIRONMENT INTERNATIONAL 2014; 71:81-7. [PMID: 24980756 PMCID: PMC4122792 DOI: 10.1016/j.envint.2014.06.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 05/07/2014] [Accepted: 06/05/2014] [Indexed: 05/18/2023]
Abstract
BACKGROUND Prenatal exposure to endocrine disrupting compounds (EDCs) has previously shown to alter epigenetic marks. OBJECTIVES In this work we explore whether prenatal exposure to mixtures of xenoestrogens has the potential to alter the placenta epigenome, by studying DNA methylation in retrotransposons as a surrogate of global DNA methylation. METHODS The biomarker total effective xenoestrogen burden (TEXB) was measured in 192 placentas from participants in the longitudinal INMA Project. DNA methylation was quantitatively assessed by bisulfite pyrosequencing on 10 different retrotransposons including 3 different long interspersed nuclear elements (LINEs), 4 short interspersed nuclear elements (SINEs) and 3 human endogenous retroviruses (HERVs). Associations were tested using linear mixed-effects regression models and sex interaction was evaluated. RESULTS A significant sex interaction was observed for AluYb8 (p-value for interaction <0.001, significant at Bonferroni corrected p-value threshold of 0.0025). Boys with the highest TEXB-alpha levels of exposure (third tertile) presented on average a decrease of 0.84% in methylation compared to those in the first tertile (p-value<0.001), while no significant effects were found in girls (p-value=0.134). CONCLUSIONS Our findings suggest that boys may be more susceptible to the effect of exposure to xenoestrogens during prenatal development, producing shifts in DNA methylation of certain sensitive genomic repetitive sequences in a tissue important for fetal growth and development.
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Affiliation(s)
- Nadia Vilahur
- Center for Research in Environmental Epidemiology (CREAL), Barcelona, Catalonia, Spain; Hospital del Mar Medical Research Institute (IMIM), Barcelona, Catalonia, Spain; Genomics and Disease Group, Bioinformatics and Genomics Program, Center for Genomic Regulation (CRG), Barcelona, Catalonia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain.
| | - Mariona Bustamante
- Center for Research in Environmental Epidemiology (CREAL), Barcelona, Catalonia, Spain; Hospital del Mar Medical Research Institute (IMIM), Barcelona, Catalonia, Spain; Genomics and Disease Group, Bioinformatics and Genomics Program, Center for Genomic Regulation (CRG), Barcelona, Catalonia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain
| | - Hyang-Min Byun
- Laboratory of Environmental Epigenetics, Exposure Epidemiology and Risk Program, Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA
| | - Mariana F Fernandez
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Department of Radiology, Centro de Investigación Biomédica, University of Granada, Granada, Spain; Instituto de Investigación Biosanitaria de Granada, Hospital Universitario San Cecilio, Granada, Spain
| | - Loreto Santa Marina
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Subdirección de Salud Pública de Gipuzkoa, Department of Health of the Basque, Spain; Health Research Institute, BIODONOSTIA, Basque Country, Spain
| | - Mikel Basterrechea
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Subdirección de Salud Pública de Gipuzkoa, Department of Health of the Basque, Spain; Health Research Institute, BIODONOSTIA, Basque Country, Spain
| | - Ferran Ballester
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Centre for Public Health Research (CSISP-FISABIO), Valencia, Spain; University of Valencia, Valencia, Spain
| | - Mario Murcia
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Centre for Public Health Research (CSISP-FISABIO), Valencia, Spain; University of Valencia, Valencia, Spain
| | - Adonina Tardón
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; University of Oviedo, Oviedo, Asturias, Spain
| | - Ana Fernández-Somoano
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; University of Oviedo, Oviedo, Asturias, Spain
| | - Xavier Estivill
- Hospital del Mar Medical Research Institute (IMIM), Barcelona, Catalonia, Spain; Genomics and Disease Group, Bioinformatics and Genomics Program, Center for Genomic Regulation (CRG), Barcelona, Catalonia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Department of Health and Life Sciences, University Pompeu Fabra (UPF), Barcelona, Catalonia, Spain
| | - Nicolas Olea
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Department of Radiology, Centro de Investigación Biomédica, University of Granada, Granada, Spain; Instituto de Investigación Biosanitaria de Granada, Hospital Universitario San Cecilio, Granada, Spain
| | - Jordi Sunyer
- Center for Research in Environmental Epidemiology (CREAL), Barcelona, Catalonia, Spain; Hospital del Mar Medical Research Institute (IMIM), Barcelona, Catalonia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Department of Health and Life Sciences, University Pompeu Fabra (UPF), Barcelona, Catalonia, Spain
| | - Andrea A Baccarelli
- Laboratory of Environmental Epigenetics, Exposure Epidemiology and Risk Program, Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA
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Distinct isoform of FABP7 revealed by screening for retroelement-activated genes in diffuse large B-cell lymphoma. Proc Natl Acad Sci U S A 2014; 111:E3534-43. [PMID: 25114248 DOI: 10.1073/pnas.1405507111] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Remnants of ancient transposable elements (TEs) are abundant in mammalian genomes. These sequences harbor multiple regulatory motifs and hence are capable of influencing expression of host genes. In response to environmental changes, TEs are known to be released from epigenetic repression and to become transcriptionally active. Such activation could also lead to lineage-inappropriate activation of oncogenes, as one study described in Hodgkin lymphoma. However, little further evidence for this mechanism in other cancers has been reported. Here, we reanalyzed whole transcriptome data from a large cohort of patients with diffuse large B-cell lymphoma (DLBCL) compared with normal B-cell centroblasts to detect genes ectopically expressed through activation of TE promoters. We have identified 98 such TE-gene chimeric transcripts that were exclusively expressed in primary DLBCL cases and confirmed several in DLBCL-derived cell lines. We further characterized a TE-gene chimeric transcript involving a fatty acid-binding protein gene (LTR2-FABP7), normally expressed in brain, that was ectopically expressed in a subset of DLBCL patients through the use of an endogenous retroviral LTR promoter of the LTR2 family. The LTR2-FABP7 chimeric transcript encodes a novel chimeric isoform of the protein with characteristics distinct from native FABP7. In vitro studies reveal a dependency for DLBCL cell line proliferation and growth on LTR2-FABP7 chimeric protein expression. Taken together, these data demonstrate the significance of TEs as regulators of aberrant gene expression in cancer and suggest that LTR2-FABP7 may contribute to the pathogenesis of DLBCL in a subgroup of patients.
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Mourier T, Nielsen LP, Hansen AJ, Willerslev E. Transposable elements in cancer as a by-product of stress-induced evolvability. Front Genet 2014; 5:156. [PMID: 24910642 PMCID: PMC4038923 DOI: 10.3389/fgene.2014.00156] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 05/11/2014] [Indexed: 01/18/2023] Open
Abstract
Transposable elements (TEs) are ubiquitous in eukaryotic genomes. Barbara McClintock's famous notion of TEs acting as controlling elements modifying the genetic response of an organism upon exposure to stressful environments has since been solidly supported in a series of model organisms. This requires the TE activity response to possess an element of specificity and be targeted toward certain parts of the genome. We propose that a similar TE response is present in human cells, and that this stress response may drive the onset of human cancers. As such, TE-driven cancers may be viewed as an evolutionary by-product of organisms' abilities to genetically adapt to environmental stress.
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Affiliation(s)
- Tobias Mourier
- Natural History Museum of Denmark, Centre for GeoGenetics, University of Copenhagen Copenhagen, Denmark
| | - Lars P Nielsen
- Department of Virology and the Danish National Biobank, Statens Serum Institut Copenhagen, Denmark
| | - Anders J Hansen
- Natural History Museum of Denmark, Centre for GeoGenetics, University of Copenhagen Copenhagen, Denmark
| | - Eske Willerslev
- Natural History Museum of Denmark, Centre for GeoGenetics, University of Copenhagen Copenhagen, Denmark
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Crichton JH, Dunican DS, MacLennan M, Meehan RR, Adams IR. Defending the genome from the enemy within: mechanisms of retrotransposon suppression in the mouse germline. Cell Mol Life Sci 2014; 71:1581-605. [PMID: 24045705 PMCID: PMC3983883 DOI: 10.1007/s00018-013-1468-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 08/27/2013] [Accepted: 08/29/2013] [Indexed: 12/15/2022]
Abstract
The viability of any species requires that the genome is kept stable as it is transmitted from generation to generation by the germ cells. One of the challenges to transgenerational genome stability is the potential mutagenic activity of transposable genetic elements, particularly retrotransposons. There are many different types of retrotransposon in mammalian genomes, and these target different points in germline development to amplify and integrate into new genomic locations. Germ cells, and their pluripotent developmental precursors, have evolved a variety of genome defence mechanisms that suppress retrotransposon activity and maintain genome stability across the generations. Here, we review recent advances in understanding how retrotransposon activity is suppressed in the mammalian germline, how genes involved in germline genome defence mechanisms are regulated, and the consequences of mutating these genome defence genes for the developing germline.
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Affiliation(s)
- James H. Crichton
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU UK
| | - Donncha S. Dunican
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU UK
| | - Marie MacLennan
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU UK
| | - Richard R. Meehan
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU UK
| | - Ian R. Adams
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU UK
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The saga of XMRV: a virus that infects human cells but is not a human virus. Emerg Microbes Infect 2014; 3:e. [PMID: 26038516 PMCID: PMC4008767 DOI: 10.1038/emi.2014.25] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 02/12/2014] [Accepted: 02/14/2014] [Indexed: 01/17/2023]
Abstract
Xenotropic murine leukemia virus-related virus (XMRV) was discovered in 2006 in a search for a viral etiology of human prostate cancer (PC). Substantial interest in XMRV as a potentially new pathogenic human retrovirus was driven by reports that XMRV could be detected in a significant percentage of PC samples, and also in tissues from patients with chronic fatigue syndrome (CFS). After considerable controversy, etiologic links between XMRV and these two diseases were disproven. XMRV was determined to have arisen during passage of a human PC tumor in immunocompromised nude mice, by activation and recombination between two endogenous murine leukemia viruses from cells of the mouse. The resulting XMRV had a xentropic host range, which allowed it replicate in the human tumor cells in the xenograft. This review describes the discovery of XMRV, and the molecular and virological events leading to its formation, XMRV infection in animal models and biological effects on infected cells. Lessons from XMRV for other searches of viral etiologies of cancer are discussed, as well as cautions for researchers working on human tumors or cell lines that have been passed through nude mice, includingpotential biohazards associated with XMRV or other similar xenotropic murine leukemia viruses (MLVs).
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Abstract
Joint infectious causation of cancer has been accepted in a few well-studied instances, including Burkitt's lymphoma and liver cancer. In general, evidence for the involvement of parasitic agents in oncogenesis has expanded, and recent advances in the application of molecular techniques have revealed specific mechanisms by which host cells are transformed. Many parasites evolve to circumvent immune-mediated detection and destruction and to control critical aspects of host cell reproduction and survival: cell proliferation, apoptosis, adhesion, and immortalization. The host has evolved tight regulation of these cellular processes-the control of each represents a barrier to cancer. These barriers need to be compromised for oncogenesis to occur. The abrogation of a barrier is therefore referred to as an essential cause of cancer. Alternatively, some aspects of cellular regulation restrain but do not block oncogenesis. Relaxation of a restraint is therefore referred to as an exacerbating cause of cancer. In this chapter, we explore past and current evidence for joint infectious causation of cancer in the context of essential and exacerbating causes. We stress that discovery of joint infectious causation may provide great improvements in controlling cancer, particularly through the identification of many additional nonhuman targets for synergistic interventions for prevention and treatment.
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Affiliation(s)
- Paul W Ewald
- Department of Biology, University of Louisville, Louisville, Kentucky, USA.
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Li L, Lorzadeh A, Hirst M. Regulatory variation: an emerging vantage point for cancer biology. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2013; 6:37-59. [DOI: 10.1002/wsbm.1250] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Luolan Li
- Centre for High-Throughput Biology, Department of Microbiology & Immunology; University of British Columbia; Vancouver, British Columbia Canada
| | - Alireza Lorzadeh
- Centre for High-Throughput Biology, Department of Microbiology & Immunology; University of British Columbia; Vancouver, British Columbia Canada
| | - Martin Hirst
- Centre for High-Throughput Biology, Department of Microbiology & Immunology; University of British Columbia; Vancouver, British Columbia Canada
- Canada's Michael Smith Genome Sciences Centre; BC Cancer Agency; Vancouver, British Columbia Canada
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Assinger A, Yaiw KC, Göttesdorfer I, Leib-Mösch C, Söderberg-Nauclér C. Human cytomegalovirus (HCMV) induces human endogenous retrovirus (HERV) transcription. Retrovirology 2013; 10:132. [PMID: 24219971 PMCID: PMC3842806 DOI: 10.1186/1742-4690-10-132] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 10/30/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Emerging evidence suggests that human cytomegalovirus (HCMV) is highly prevalent in tumours of different origin. This virus is implied to have oncogenic and oncomodulatory functions, through its ability to control host gene expression. Human endogenous retroviruses (HERV) are also frequently active in tumours of different origin, and are supposed to contribute as cofactors to cancer development. Due to the high prevalence of HCMV in several different tumours, and its ability to control host cell gene expression, we sought to define whether HCMV may affect HERV transcription. FINDINGS Infection of 3 established cancer cell lines, 2 primary glioblastoma cells, endothelial cells from 3 donors and monocytes from 4 donors with HCMV (strains VR 1814 or TB40/F) induced reverse transcriptase (RT) activity in all cells tested, but the response varied between donors. Both, gammaretrovirus-related class I elements HERV-T, HERV-W, HERV-F and ERV-9, and betaretrovirus-related class II elements HML-2 - 4 and HML-7 - 8, as well as spuma-virus related class III elements of the HERV-L group were up-regulated in response to HCMV infection in GliNS1 cells. Up-regulation of HERV activity was more pronounced in cells harbouring active HCMV infection, but was also induced by UV-inactivated virus. The effect was only slightly affected by ganciclovir treatment and was not controlled by the IE72 or IE86 HCMV genes. CONCLUSIONS Within this brief report we show that HCMV infection induces HERV transcriptional activity in different cell types.
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Affiliation(s)
| | | | | | | | - Cecilia Söderberg-Nauclér
- Center for Molecular Medicine, Department of Medicine, Karolinska Institutet, SE-171 76 Stockholm, Sweden.
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Prevalence of human endogenous retroviral element associates with Hodgkin's lymphoma incidence rates. Leuk Res Rep 2013; 3:1-3. [PMID: 24596672 PMCID: PMC3939381 DOI: 10.1016/j.lrr.2013.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Revised: 10/08/2013] [Accepted: 10/21/2013] [Indexed: 12/03/2022] Open
Abstract
Human endogenous retrovirus-H (HERV-H) is implicated in leukaemias and lymphomas, but the precise molecular mechanism underlying HERV-mediated carcinogenesis remains unknown. We determined the prevalence of HERV-H in a cross-section of the Singapore population and explored the relationship between HERV-H positivity and incidence rates for Hodgkin's lymphoma in three major ethnic groups of Singapore. We observed that Malays were 1.11 times likely (95% CI=1.05–1.17; P<0.01), and Indians 1.12 times likely (95% CI=1.07–1.18; P<0.01) to be HERV-H positive when compared to Chinese. Interestingly, the incidence rates of Hodgkin's lymphoma for the three races positively correlated to the respective prevalence rate for HERV-H positivity (r=0.9921 for male; r=0.9801 for female), suggesting that viral inheritance in human may predispose certain racial origin unfavourably to malignancy.
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46
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Maliniemi P, Vincendeau M, Mayer J, Frank O, Hahtola S, Karenko L, Carlsson E, Mallet F, Seifarth W, Leib-Mösch C, Ranki A. Expression of human endogenous retrovirus-w including syncytin-1 in cutaneous T-cell lymphoma. PLoS One 2013; 8:e76281. [PMID: 24098463 PMCID: PMC3788054 DOI: 10.1371/journal.pone.0076281] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 08/22/2013] [Indexed: 12/03/2022] Open
Abstract
The pathomechanism of mycosis fungoides (MF), the most common type of primary cutaneous T-cell lymphomas (CTCLs) and a malignancy of non-recirculating, skin-resident T-cells, is unknown albeit underlying viral infections have been sought for. Human endogenous retroviruses (HERVs) are ancient retroviral sequences in the human genome and their transcription is often deregulated in cancers. We explored the transcriptional activity of HERV sequences in a total of 34 samples comprising MF and psoriasis skin lesions, as well as corresponding non-malignant skin using a retrovirus-specific microarray and quantitative RT-PCR. To identify active HERV-W loci, we cloned the HERV-W specific RT-PCR products, sequenced the cDNA clones and assigned the sequences to HERV-W loci. Finally, we used immunohistochemistry on MF patient and non-malignant inflammatory skin samples to confirm specific HERV-encoded protein expression. Firstly, a distinct, skin-specific transcription profile consisting of five constitutively active HERV groups was established. Although individual variability was common, HERV-W showed significantly increased transcription in MF lesions compared to clinically intact skin from the same patient. Predominantly transcribed HERV-W loci were found to be located in chromosomes 6q21 and 7q21.2, chromosomal regions typically altered in CTCL. Surprisingly, we also found the expression of 7q21.2/ERVWE1-encoded Syncytin-1 (Env) protein in MF biopsies and expression of Syncytin-1 was seen in malignant lymphocytes, especially in the epidermotropic ones, in 15 of 30 cases studied. Most importantly, no Syncytin-1 expression was detected in inflammatory dermatosis (Lichen ruber planus) with skin-homing, non-malignant T lymphocytes. The expression of ERVWE1 mRNA was further confirmed in 3/7 MF lesions analyzed. Our observations strengthen the association between activated HERVs and cancer. The study offers a new perspective into the pathogenesis of CTCL since we demonstrate that differences in HERV-W transcription levels between lesional MF and non-malignant skin are significant, and that ERVWE1-encoded Syncytin-1 is expressed in MF lymphoma cells.
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Affiliation(s)
- Pilvi Maliniemi
- Department of Dermatology and Allergology, Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland
- * E-mail:
| | - Michelle Vincendeau
- Institute of Virology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Research Unit Cellular Signal Integration, Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Jens Mayer
- Department of Human Genetics, Center of Human and Molecular Biology, Medical Faculty, University of Saarland, Homburg, Germany
| | - Oliver Frank
- Department of Hematology and Oncology, Mannheim Medical Center, University of Heidelberg, Mannheim, Germany
| | - Sonja Hahtola
- Department of Dermatology and Allergology, Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland
| | - Leena Karenko
- Department of Dermatology and Allergology, Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland
| | - Emilia Carlsson
- Department of Dermatology and Allergology, Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland
| | - Francois Mallet
- Joint Unit Hospices Civils de Lyon-bioMérieux, Cancer Biomarkers Research Group, Centre Hospitalier Lyon Sud, Pierre Bénite, France
| | - Wolfgang Seifarth
- Department of Hematology and Oncology, Mannheim Medical Center, University of Heidelberg, Mannheim, Germany
| | - Christine Leib-Mösch
- Institute of Virology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Department of Hematology and Oncology, Mannheim Medical Center, University of Heidelberg, Mannheim, Germany
| | - Annamari Ranki
- Department of Dermatology and Allergology, Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland
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Nordlund J, Bäcklin CL, Wahlberg P, Busche S, Berglund EC, Eloranta ML, Flaegstad T, Forestier E, Frost BM, Harila-Saari A, Heyman M, Jónsson OG, Larsson R, Palle J, Rönnblom L, Schmiegelow K, Sinnett D, Söderhäll S, Pastinen T, Gustafsson MG, Lönnerholm G, Syvänen AC. Genome-wide signatures of differential DNA methylation in pediatric acute lymphoblastic leukemia. Genome Biol 2013; 14:r105. [PMID: 24063430 PMCID: PMC4014804 DOI: 10.1186/gb-2013-14-9-r105] [Citation(s) in RCA: 255] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 09/24/2013] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Although aberrant DNA methylation has been observed previously in acute lymphoblastic leukemia (ALL), the patterns of differential methylation have not been comprehensively determined in all subtypes of ALL on a genome-wide scale. The relationship between DNA methylation, cytogenetic background, drug resistance and relapse in ALL is poorly understood. RESULTS We surveyed the DNA methylation levels of 435,941 CpG sites in samples from 764 children at diagnosis of ALL and from 27 children at relapse. This survey uncovered four characteristic methylation signatures. First, compared with control blood cells, the methylomes of ALL cells shared 9,406 predominantly hypermethylated CpG sites, independent of cytogenetic background. Second, each cytogenetic subtype of ALL displayed a unique set of hyper- and hypomethylated CpG sites. The CpG sites that constituted these two signatures differed in their functional genomic enrichment to regions with marks of active or repressed chromatin. Third, we identified subtype-specific differential methylation in promoter and enhancer regions that were strongly correlated with gene expression. Fourth, a set of 6,612 CpG sites was predominantly hypermethylated in ALL cells at relapse, compared with matched samples at diagnosis. Analysis of relapse-free survival identified CpG sites with subtype-specific differential methylation that divided the patients into different risk groups, depending on their methylation status. CONCLUSIONS Our results suggest an important biological role for DNA methylation in the differences between ALL subtypes and in their clinical outcome after treatment.
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Hohn O, Hanke K, Bannert N. HERV-K(HML-2), the Best Preserved Family of HERVs: Endogenization, Expression, and Implications in Health and Disease. Front Oncol 2013; 3:246. [PMID: 24066280 PMCID: PMC3778440 DOI: 10.3389/fonc.2013.00246] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 09/05/2013] [Indexed: 12/14/2022] Open
Abstract
Retroviruses that have the ability to infect germ line cells can become an integral and inherited part of the host genome. About 8% of the human chromosomal DNA consists of sequences derived from infections by retroviruses that presumably circulated 2-40 millions of years ago, and some elements are actually much older. Post-insertional recombinations, deletions, and mutations have rendered all known human endogenous retroviruses (HERVs) non-infectious. However some, particularly the most recently acquired proviruses of the HERV-K(HML-2) family, can expresses viral proteins and produce viral particles. In this review we will first discuss the major aspects of the endogenization process and peculiarities of the different HERV-K families. We will then focus on the genes and proteins encoded by HERV-K(HML-2) as well as inactivation of these proviruses by postinsertional mutations and their inhibition by antiretroviral factors. After describing the evolutionary interplay between host and endogenous retrovirus we will delve deeper into the currently limited understanding of HERV-K and its possible association with disease, particularly tumorigenesis.
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Affiliation(s)
- Oliver Hohn
- Division for HIV and Other Retroviruses, Robert Koch Institute , Berlin , Germany
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49
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Katoh I, Kurata SI. Association of endogenous retroviruses and long terminal repeats with human disorders. Front Oncol 2013; 3:234. [PMID: 24062987 PMCID: PMC3769647 DOI: 10.3389/fonc.2013.00234] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 08/27/2013] [Indexed: 01/31/2023] Open
Abstract
Since the human genome sequences became available in 2001, our knowledge about the human transposable elements which comprise ∼40% of the total nucleotides has been expanding. Non-long terminal repeat (non-LTR) retrotransposons are actively transposing in the present-day human genome, and have been found to cause ∼100 identified clinical cases of varied disorders. In contrast, almost all of the human endogenous retroviruses (HERVs) originating from ancient infectious retroviruses lost their infectivity and transposing activity at various times before the human-chimpanzee speciation (∼6 million years ago), and no known HERV is presently infectious. Insertion of HERVs and mammalian apparent LTR retrotransposons (MaLRs) into the chromosomal DNA influenced a number of host genes in various modes during human evolution. Apart from the aspect of genome evolution, HERVs and solitary LTRs being suppressed in normal biological processes can potentially act as extra transcriptional apparatuses of cellular genes by re-activation in individuals. There has been a reasonable prediction that aberrant LTR activation could trigger malignant disorders and autoimmune responses if epigenetic changes including DNA hypomethylation occur in somatic cells. Evidence supporting this hypothesis has begun to emerge only recently: a MaLR family LTR activation in the pathogenesis of Hodgkin’s lymphoma and a HERV-E antigen expression in an anti-renal cell carcinoma immune response. This mini review addresses the impacts of the remnant-form LTR retrotransposons on human pathogenesis.
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Affiliation(s)
- Iyoko Katoh
- Department of Microbiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi , Chuo, Yamanashi , Japan
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50
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Severson PL, Tokar EJ, Vrba L, Waalkes MP, Futscher BW. Coordinate H3K9 and DNA methylation silencing of ZNFs in toxicant-induced malignant transformation. Epigenetics 2013; 8:1080-8. [PMID: 23974009 PMCID: PMC3891689 DOI: 10.4161/epi.25926] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Genome-wide disruption of the epigenetic code is a hallmark of malignancy that encompasses many distinct, highly interactive modifications. Delineating the aberrant epigenome produced during toxicant-mediated malignant transformation will help identify the underlying epigenetic drivers of environmental toxicant-induced carcinogenesis. Gene promoter DNA methylation and gene expression profiling of arsenite-transformed prostate epithelial cells showed a negative correlation between gene expression changes and DNA methylation changes; however, less than 10% of the genes with increased promoter methylation were downregulated. Studies described herein confirm that a majority of the DNA hypermethylation events occur at H3K27me3 marked genes that were already transcriptionally repressed. In contrast to aberrant DNA methylation targeting H3K27me3 pre-marked silent genes, we found that actively expressed C2H2 zinc finger genes (ZNFs) marked with H3K9me3 on their 3′ ends, were the favored targets of DNA methylation linked gene silencing. DNA methylation coupled, H3K9me3 mediated gene silencing of ZNF genes was widespread, occurring at individual ZNF genes on multiple chromosomes and across ZNF gene family clusters. At ZNF gene promoters, H3K9me3 and DNA hypermethylation replaced H3K4me3, resulting in a widespread downregulation of ZNF gene expression, which accounted for 8% of all the downregulated genes in the arsenical-transformed cells. In summary, these studies associate toxicant exposure with widespread silencing of ZNF genes by DNA hypermethylation-linked H3K9me3 spreading, further implicating epigenetic dysfunction as a driver of toxicant associated carcinogenesis.
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Affiliation(s)
- Paul L Severson
- Department of Pharmacology and Toxicology; College of Pharmacy; University of Arizona; Tucson, AZ USA
| | - Erik J Tokar
- National Toxicology Program Laboratory; National Institute of Environmental Health Sciences; Research Triangle Park, NC USA
| | - Lukas Vrba
- University of Arizona Cancer Center; Tucson, AZ USA
| | - Michael P Waalkes
- National Toxicology Program Laboratory; National Institute of Environmental Health Sciences; Research Triangle Park, NC USA
| | - Bernard W Futscher
- Department of Pharmacology and Toxicology; College of Pharmacy; University of Arizona; Tucson, AZ USA; University of Arizona Cancer Center; Tucson, AZ USA
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