1
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Yi JM. Epigenetic regulation of HERVs: Implications for cancer immunotherapy. Genes Genomics 2024:10.1007/s13258-024-01546-2. [PMID: 39088189 DOI: 10.1007/s13258-024-01546-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Accepted: 07/07/2024] [Indexed: 08/02/2024]
Abstract
BACKGROUND Human endogenous retroviruses (HERVs), integrated into the human genome during primate evolution, constitute approximately 8% of the human genome. Although most HERVs are non-protein-coding owing to mutations, insertions, deletions, and truncations, recent research has revealed their diverse roles in biological processes, including disease pathogenesis. OBJECTIVE Although many HERVs remain inactive, they have been implicated in various diseases, particularly cancer, prompting an increased interest in harnessing HERVs for therapeutic purposes. This review explores the recent advancements in our understanding of the biological roles of HERVs, emphasizing their clinical relevance in cancer treatment. METHODS Here, we discuss how the detection of transposable elements (TEs), including HERVs, by the immune system triggers innate immune responses in human cancers. CONCLUSION Additionally, we outline recent progress in elucidating the implications of HERV activation in cancer and how targeting HERVs holds promise for anti-cancer treatments by modulating epigenetic plasticity and disrupting cancer initiation and progression.
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Affiliation(s)
- Joo Mi Yi
- Department of Microbiology and Immunology, College of Medicine, Inje University, Busan, 47392, South Korea.
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, Bloomington, IN, 47405, USA.
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2
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Terrazzan A, Vanini R, Ancona P, Bianchi N, Taccioli C, Aguiari G. State-of-the-art in transposable element modulation affected by drugs in malignant prostatic cancer cells. J Cell Biochem 2024; 125:e30557. [PMID: 38501160 DOI: 10.1002/jcb.30557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 02/14/2024] [Accepted: 03/07/2024] [Indexed: 03/20/2024]
Abstract
Over recent years, the investigation of transposable elements (TEs) has granted researchers a deeper comprehension of their characteristics and functions, particularly regarding their significance in the mechanisms contributing to cancer development. This manuscript focuses on prostate carcinoma cell lines and offers a comprehensive review intended to scrutinize the associations and interactions between TEs and genes, as well as their response to treatment using various chemical drugs, emphasizing their involvement in cancer progression. We assembled a compendium of articles retrieved from the PubMed database to construct networks demonstrating correlations with genes and pharmaceuticals. In doing so, we linked the transposition of certain TE types to the expression of specific transcripts directly implicated in carcinogenesis. Additionally, we underline that treatment employing different drugs revealed unique patterns of TE reactivation. Our hypothesis gathers the current understanding and guides research toward evidence-based investigations, emphasizing the association between antiviral drugs, chemotherapy, and the reduced expression of TEs in patients affected by prostate cancer.
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Affiliation(s)
- Anna Terrazzan
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
- Laboratory for Advanced Therapy Technologies (LTTA), University of Ferrara, Ferrara, Italy
| | - Riccardo Vanini
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
| | - Pietro Ancona
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
| | - Nicoletta Bianchi
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
| | - Cristian Taccioli
- Department of Animal Medicine, Production and Health (MAPS), University of Padua, Padua, Italy
| | - Gianluca Aguiari
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
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3
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Shah AH, Rivas SR, Doucet-O’Hare TT, Govindarajan V, DeMarino C, Wang T, Ampie L, Zhang Y, Banasavadi-Siddegowda YK, Walbridge S, Maric D, Garcia-Montojo M, Suter RK, Lee MH, Zaghloul KA, Steiner J, Elkahloun AG, Chandar J, Seetharam D, Desgraves J, Li W, Johnson K, Ivan ME, Komotar RJ, Gilbert MR, Heiss JD, Nath A. Human endogenous retrovirus K contributes to a stem cell niche in glioblastoma. J Clin Invest 2023; 133:e167929. [PMID: 37395282 PMCID: PMC10313366 DOI: 10.1172/jci167929] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 05/19/2023] [Indexed: 07/04/2023] Open
Abstract
Human endogenous retroviruses (HERVs) are ancestral viral relics that constitute nearly 8% of the human genome. Although normally silenced, the most recently integrated provirus HERV-K (HML-2) can be reactivated in certain cancers. Here, we report pathological expression of HML-2 in malignant gliomas in both cerebrospinal fluid and tumor tissue that was associated with a cancer stem cell phenotype and poor outcomes. Using single-cell RNA-Seq, we identified glioblastoma cellular populations with elevated HML-2 transcripts in neural progenitor-like cells (NPC-like) that drive cellular plasticity. Using CRISPR interference, we demonstrate that HML-2 critically maintained glioblastoma stemness and tumorigenesis in both glioblastoma neurospheres and intracranial orthotopic murine models. Additionally, we demonstrate that HML-2 critically regulated embryonic stem cell programs in NPC-derived astroglia and altered their 3D cellular morphology by activating the nuclear transcription factor OCT4, which binds to an HML-2-specific long-terminal repeat (LTR5Hs). Moreover, we discovered that some glioblastoma cells formed immature retroviral virions, and inhibiting HML-2 expression with antiretroviral drugs reduced reverse transcriptase activity in the extracellular compartment, tumor viability, and pluripotency. Our results suggest that HML-2 fundamentally contributes to the glioblastoma stem cell niche. Because persistence of glioblastoma stem cells is considered responsible for treatment resistance and recurrence, HML-2 may serve as a unique therapeutic target.
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Affiliation(s)
- Ashish H. Shah
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Sarah R. Rivas
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Tara T. Doucet-O’Hare
- Neuro-Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Vaidya Govindarajan
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Catherine DeMarino
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Tongguang Wang
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Leonel Ampie
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Yong Zhang
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | | | - Stuart Walbridge
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Dragan Maric
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Marta Garcia-Montojo
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Robert K. Suter
- Georgetown University, Bioinformatics Section, Washington, DC, USA
| | - Myoung-Hwa Lee
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Kareem A. Zaghloul
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Joseph Steiner
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Abdel G. Elkahloun
- Cancer Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, Maryland, USA
| | - Jay Chandar
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Deepa Seetharam
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Jelisah Desgraves
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Wenxue Li
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Kory Johnson
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Michael E. Ivan
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Ricardo J. Komotar
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Mark R. Gilbert
- Neuro-Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - John D. Heiss
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Avindra Nath
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
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4
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Felley-Bosco E. Exploring the Expression of the «Dark Matter» of the Genome in Mesothelioma for Potentially Predictive Biomarkers for Prognosis and Immunotherapy. Cancers (Basel) 2023; 15:cancers15112969. [PMID: 37296931 DOI: 10.3390/cancers15112969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/21/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023] Open
Abstract
Recent high-throughput RNA sequencing technologies have confirmed that a large part of the non-coding genome is transcribed. The priority for further investigations is nevertheless generally given in cancer to coding sequences, due to the obvious interest of finding therapeutic targets. In addition, several RNA-sequencing pipelines eliminate repetitive sequences, which are difficult to analyze. In this review, we shall focus on endogenous retroviruses. These sequences are remnants of ancestral germline infections by exogenous retroviruses. These sequences represent 8% of human genome, meaning four-fold the fraction of the genome encoding for proteins. These sequences are generally mostly repressed in normal adult tissues, but pathological conditions lead to their de-repression. Specific mesothelioma-associated endogenous retrovirus expression and their association to clinical outcome is discussed.
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Affiliation(s)
- Emanuela Felley-Bosco
- Laboratory of Molecular Oncology, Department of Thoracic Surgery, Zürich University Hospital, 8091 Zurich, Switzerland
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5
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Stricker E, Peckham-Gregory EC, Scheurer ME. HERVs and Cancer-A Comprehensive Review of the Relationship of Human Endogenous Retroviruses and Human Cancers. Biomedicines 2023; 11:936. [PMID: 36979914 PMCID: PMC10046157 DOI: 10.3390/biomedicines11030936] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/03/2023] [Accepted: 03/10/2023] [Indexed: 03/30/2023] Open
Abstract
Genomic instability and genetic mutations can lead to exhibition of several cancer hallmarks in affected cells such as sustained proliferative signaling, evasion of growth suppression, activated invasion, deregulation of cellular energetics, and avoidance of immune destruction. Similar biological changes have been observed to be a result of pathogenic viruses and, in some cases, have been linked to virus-induced cancers. Human endogenous retroviruses (HERVs), once external pathogens, now occupy more than 8% of the human genome, representing the merge of genomic and external factors. In this review, we outline all reported effects of HERVs on cancer development and discuss the HERV targets most suitable for cancer treatments as well as ongoing clinical trials for HERV-targeting drugs. We reviewed all currently available reports of the effects of HERVs on human cancers including solid tumors, lymphomas, and leukemias. Our review highlights the central roles of HERV genes, such as gag, env, pol, np9, and rec in immune regulation, checkpoint blockade, cell differentiation, cell fusion, proliferation, metastasis, and cell transformation. In addition, we summarize the involvement of HERV long terminal repeat (LTR) regions in transcriptional regulation, creation of fusion proteins, expression of long non-coding RNAs (lncRNAs), and promotion of genome instability through recombination.
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Affiliation(s)
- Erik Stricker
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77047, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77047, USA
| | | | - Michael E. Scheurer
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77047, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77047, USA
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6
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Fan TJ, Cui J. Human Endogenous Retroviruses in Diseases. Subcell Biochem 2023; 106:403-439. [PMID: 38159236 DOI: 10.1007/978-3-031-40086-5_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Human endogenous retroviruses (HERVs), which are conserved sequences of ancient retroviruses, are widely distributed in the human genome. Although most HERVs have been rendered inactive by evolution, some have continued to exhibit important cytological functions. HERVs in the human genome perform dual functions: on the one hand, they are involved in important physiological processes such as placental development and immune regulation; on the other hand, their aberrant expression is closely associated with the pathological processes of several diseases, such as cancers, autoimmune diseases, and viral infections. HERVs can also regulate a variety of host cellular functions, including the expression of protein-coding genes and regulatory elements that have evolved from HERVs. Here, we present recent research on the roles of HERVs in viral infections and cancers, including the dysregulation of HERVs in various viral infections, HERV-induced epigenetic modifications of histones (such as methylation and acetylation), and the potential mechanisms of HERV-mediated antiviral immunity. We also describe therapies to improve the efficacy of vaccines and medications either by directly or indirectly targeting HERVs, depending on the HERV.
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Affiliation(s)
- Tian-Jiao Fan
- CAS Key Laboratory of Molecular Virology & Immunology, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, China
| | - Jie Cui
- CAS Key Laboratory of Molecular Virology & Immunology, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, China.
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7
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Rivas SR, Valdez MJM, Govindarajan V, Seetharam D, Doucet-O’Hare TT, Heiss JD, Shah AH. The Role of HERV-K in Cancer Stemness. Viruses 2022; 14:v14092019. [PMID: 36146825 PMCID: PMC9504571 DOI: 10.3390/v14092019] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/29/2022] [Accepted: 09/05/2022] [Indexed: 12/15/2022] Open
Abstract
Human endogenous retrovirus-K (HERV-K) is the most recently integrated retrovirus in the human genome, with implications for multiple disorders, including cancer. Although typically transcriptionally silenced in normal adult cells, dysregulation of HERV-K (HML-2) elements has been observed in cancer, including breast, germ cell tumors, pancreatic, melanoma, and brain cancer. While multiple methods of carcinogenesis have been proposed, here we discuss the role of HERV-K (HML-2) in the promotion and maintenance of the stem-cell in cancer. Aberrant expression of HERV-K has been shown to promote expression of stem cell markers and promote dedifferentiation. In this review, we discuss HERV-K (HML-2) as a potential therapeutic target based on evidence that some tumors depend on the expression of its proteins for survival.
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Affiliation(s)
- Sarah R. Rivas
- Surgical Neurology Branch, National Institute of Neurological Diseases and Stroke, Bethesda, MD 20892, USA
- Correspondence: (S.R.R.); (A.H.S.)
| | - Mynor J. Mendez Valdez
- Section of Virology and Immunotherapy, Department of Neurosurgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Vaidya Govindarajan
- Section of Virology and Immunotherapy, Department of Neurosurgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Deepa Seetharam
- Section of Virology and Immunotherapy, Department of Neurosurgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Tara T. Doucet-O’Hare
- Neuro-Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - John D. Heiss
- Surgical Neurology Branch, National Institute of Neurological Diseases and Stroke, Bethesda, MD 20892, USA
| | - Ashish H. Shah
- Section of Virology and Immunotherapy, Department of Neurosurgery, Leonard M. Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- Correspondence: (S.R.R.); (A.H.S.)
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8
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Varkoly K, Tan S, Beladi R, Fonseca D, Zanetti IR, Kraberger S, Shah C, Yaron JR, Zhang L, Juby M, Fath A, Ambadapadi S, House M, Maranian P, Pepine CJ, Varsani A, Moreb J, Schultz-Cherry S, Lucas AR. RNA Virus Gene Signatures Detected in Patients With Cardiomyopathy After Chemotherapy; A Pilot Study. Front Cardiovasc Med 2022; 9:821162. [PMID: 35360008 PMCID: PMC8962958 DOI: 10.3389/fcvm.2022.821162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/20/2022] [Indexed: 11/13/2022] Open
Abstract
Background Viral infections are pervasive and leading causes of myocarditis. Immune-suppression after chemotherapy increases opportunistic infections, but the incidence of virus-induced myocarditis is unknown. Objective An unbiased, blinded screening for RNA viruses was performed after chemotherapy with correlation to cardiac function. Methods High-throughput sequencing of RNA isolated from blood samples was analyzed following chemotherapy for hematological malignancies (N = 28) and compared with left ventricular ejection fraction (LVEF). Results On initial rigorous analysis, low levels of influenza orthomyxovirus and avian paramyxovirus sequences were detectable, but without significant correlation to LVEF (r = 0.208). A secondary broad data mining analysis for virus sequences, without filtering human sequences, detected significant correlations for paramyxovirus with LVEF after chemotherapy (r = 0.592, P < 0.0096). Correlations were similar for LVEF pre- and post- chemotherapy for orthomyxovirus (R = 0.483, P < 0.0421). Retrovirus detection also correlated with LVEF post (r = 0.453, p < 0.0591), but not pre-chemotherapy, but is suspect due to potential host contamination. Detectable phage and anellovirus had no correlation. Combined sequence reads (all viruses) demonstrated significant correlation (r = 0.621, P < 0.0078). Reduced LVEF was not associated with chemotherapy (P = NS). Conclusions This is the first report of RNA virus screening in circulating blood and association with changes in cardiac function among patients post chemotherapy, using unbiased, blinded, high-throughput sequencing. Influenza orthomyxovirus, avian paramyxovirus and retrovirus sequences were detectable in patients with reduced LVEF. Further analysis for RNA virus infections in patients with cardiomyopathy after chemotherapy is warranted.
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Affiliation(s)
- Kyle Varkoly
- Department of Internal Medicine, McLaren Macomb Hospital- Michigan State University College of Human Medicine, Mt Clemens, MI, United States
- Center for Personalized Diagnostics, The Biodesign Institute, Arizona State University, Tempe, AZ, United States
| | - Shaoyuan Tan
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Roxana Beladi
- Center for Personalized Diagnostics, The Biodesign Institute, Arizona State University, Tempe, AZ, United States
- Department of Neurological Surgery, Ascension Providence Hospital- Michigan State University College of Human Medicine, Southfield, MI, United States
| | - David Fonseca
- Center for Personalized Diagnostics, The Biodesign Institute, Arizona State University, Tempe, AZ, United States
| | - Isabela Rivabem Zanetti
- Center for Personalized Diagnostics, The Biodesign Institute, Arizona State University, Tempe, AZ, United States
| | - Simona Kraberger
- The Biodesign Center of Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, United States
| | - Chintan Shah
- Division of Hematology/Oncology, Department of Medicine, University of Florida, Gainesville, FL, United States
| | - Jordan R. Yaron
- Center for Personalized Diagnostics, The Biodesign Institute, Arizona State University, Tempe, AZ, United States
- School for Engineering of Matter, Transport and Energy, Ira A. Fulton Schools of Engineering, Arizona State University, Tempe, AZ, United States
| | - Liqiang Zhang
- Center for Personalized Diagnostics, The Biodesign Institute, Arizona State University, Tempe, AZ, United States
| | - Michael Juby
- Center for Personalized Diagnostics, The Biodesign Institute, Arizona State University, Tempe, AZ, United States
| | - Ayman Fath
- Department of Internal Medicine, Dignity Health, Creighton University, Phoenix, AZ, United States
| | - Sriram Ambadapadi
- Center for Personalized Diagnostics, The Biodesign Institute, Arizona State University, Tempe, AZ, United States
| | - Melanie House
- Department of Internal Medicine, Dignity Health, Creighton University, Phoenix, AZ, United States
| | - Paul Maranian
- Center for Personalized Diagnostics, The Biodesign Institute, Arizona State University, Tempe, AZ, United States
| | - Carl J. Pepine
- Division of Cardiology, Department of Medicine, University of Florida, Gainesville, FL, United States
| | - Arvind Varsani
- The Biodesign Center of Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, United States
- Division of Cardiology, Department of Medicine, University of Florida, Gainesville, FL, United States
| | - Jan Moreb
- Hematologic Malignancies, Transplantation and Cellular Therapy Program, Forsyth Medical Center, Derrick L Davis Cancer Center, Winston-Salem, NC, United States
| | - Stacey Schultz-Cherry
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Alexandra R. Lucas
- Center for Personalized Diagnostics, The Biodesign Institute, Arizona State University, Tempe, AZ, United States
- Division of Cardiology, Department of Medicine, University of Florida, Gainesville, FL, United States
- Center for Immunotherapy, Vaccines and Virotherapy, The Biodesign Institute, Arizona State University, Tempe, AZ, United States
- *Correspondence: Alexandra R. Lucas
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9
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SMARCB1 deletion in atypical teratoid rhabdoid tumors results in human endogenous retrovirus K (HML-2) expression. Sci Rep 2021; 11:12893. [PMID: 34145313 PMCID: PMC8213802 DOI: 10.1038/s41598-021-92223-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 05/27/2021] [Indexed: 12/19/2022] Open
Abstract
Atypical Teratoid Rhabdoid Tumor (AT/RT) is a rare pediatric central nervous system cancer often characterized by deletion or mutation of SMARCB1, a tumor suppressor gene. In this study, we found that SMARCB1 regulates Human Endogenous Retrovirus K (HERV-K, subtype HML-2) expression. HML-2 is a repetitive element scattered throughout the human genome, encoding several intact viral proteins that have been associated with stem cell maintenance and tumorigenesis. We found HML-2 env expression in both the intracellular and extracellular compartments in all AT/RT cell lines (n = 4) and in 95% of AT/RT patient tissues (n = 37) evaluated. SMARCB1 knock-down in neural stem cells (NSCs) led to an upregulation of HML-2 transcription. We found that SMARCB1 binds adjacent to the HML-2 promoter, repressing its transcription via chromatin immunoprecipitation; restoration of SMARCB1 expression in AT/RT cell lines significantly downregulated HML-2 expression. Further, targeted downregulation of HML-2 transcription via CRISPR-dCas9 coupled with suppressor proteins led to cellular dispersion, decreased proliferation, and cell death in vitro. HML-2 knock-down with shRNA, siRNA, and CRISPR-dCas9 significantly decreased Ras expression as measured by qRT-PCR, suggesting that HML-2 modulates MAPK/ERK signaling in AT/RT cells. Overexpression of NRAS was sufficient to restore cellular proliferation, and MYC, a transcription factor downstream of NRAS, was bound to the HERV-K LTR significantly more in the absence of SMARCB1 expression in AT/RT cells. We show a mechanism by which these undifferentiated tumors remain pluripotent, and we demonstrate that their formation is aided by aberrant HML-2 activation, which is dependent on SMARCB1 and its interaction with MYC.
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10
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Grundy EE, Diab N, Chiappinelli KB. Transposable element regulation and expression in cancer. FEBS J 2021; 289:1160-1179. [PMID: 33471418 DOI: 10.1111/febs.15722] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 01/08/2021] [Accepted: 01/14/2021] [Indexed: 12/11/2022]
Abstract
Approximately 45% of the human genome is composed of transposable elements (TEs). Expression of these elements is tightly regulated during normal development. TEs may be expressed at high levels in embryonic stem cells but are epigenetically silenced in terminally differentiated cells. As part of the global 'epigenetic dysregulation' that cells undergo during transformation from normal to cancer, TEs can lose epigenetic silencing and become transcribed, and, in some cases, active. Here, we summarize recent advances detailing the consequences of TE activation in cancer and describe how these understudied residents of our genome can both aid tumorigenesis and potentially be harnessed for anticancer therapies.
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Affiliation(s)
- Erin E Grundy
- Department of Microbiology, Immunology, & Tropical Medicine, The George Washington University, Washington, DC, USA.,The GW Cancer Center, The George Washington University, Washington, DC, USA.,The Institute for Biomedical Sciences at The George Washington University, Washington, DC, USA
| | - Noor Diab
- Department of Microbiology, Immunology, & Tropical Medicine, The George Washington University, Washington, DC, USA.,The GW Cancer Center, The George Washington University, Washington, DC, USA
| | - Katherine B Chiappinelli
- Department of Microbiology, Immunology, & Tropical Medicine, The George Washington University, Washington, DC, USA.,The GW Cancer Center, The George Washington University, Washington, DC, USA
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11
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Gao Y, Yu XF, Chen T. Human endogenous retroviruses in cancer: Expression, regulation and function. Oncol Lett 2020; 21:121. [PMID: 33552242 PMCID: PMC7798031 DOI: 10.3892/ol.2020.12382] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/27/2020] [Indexed: 12/16/2022] Open
Abstract
Human endogenous retroviruses (HERVs) are the remnants of ancient retroviruses that infected human germline cells and became integrated into the human genome millions of years ago. Although most of these sequences are incomplete and silent, several potential pathological roles of HERVs have been observed in numerous diseases, such as multiple sclerosis and rheumatoid arthritis, and especially cancer, including breast cancer and pancreatic carcinoma. The present review investigates the expression signatures and complex regulatory mechanisms of HERVs in cancer. The long terminal repeats-driven transcriptional initiation of HERVs are regulated by transcription factors (such as Sp3) and epigenetic modifications (such as DNA methylation), and are influenced by environmental factors (such as ultraviolet radiation). In addition, this review focuses on the dual opposing effects of HERVs in cancer. HERVs can suppress cancer via immune activation; however, they can also promote cancer. HERV env gene serves a prime role in promoting carcinogenesis in certain malignant tumors, including breast cancer, pancreatic cancer, germ cell tumors, leukemia and Kaposi's sarcoma. Also, HERV ENV proteins can promote cancer via immune suppression. Targeting ENV proteins is a potential future antitumor treatment modality.
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Affiliation(s)
- Yuan Gao
- Cancer Institute, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zheijang 310009, P.R. China
| | - Xiao-Fang Yu
- Cancer Institute, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zheijang 310009, P.R. China
| | - Ting Chen
- Cancer Institute, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zheijang 310009, P.R. China
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12
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Human Endogenous Retrovirus K Rec forms a Regulatory Loop with MITF that Opposes the Progression of Melanoma to an Invasive Stage. Viruses 2020; 12:v12111303. [PMID: 33202765 PMCID: PMC7696977 DOI: 10.3390/v12111303] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 12/19/2022] Open
Abstract
The HML2 subfamily of HERV-K (henceforth HERV-K) represents the most recently endogenized retrovirus in the human genome. While the products of certain HERV-K genomic copies are expressed in normal tissues, they are upregulated in several pathological conditions, including various tumors. It remains unclear whether HERV-K(HML2)-encoded products overexpressed in cancer contribute to disease progression or are merely by-products of tumorigenesis. Here, we focus on the regulatory activities of the Long Terminal Repeats (LTR5_Hs) of HERV-K and the potential role of the HERV-K-encoded Rec in melanoma. Our regulatory genomics analysis of LTR5_Hs loci indicates that Melanocyte Inducing Transcription Factor (MITF) (also known as binds to a canonical E-box motif (CA(C/T)GTG) within these elements in proliferative type of melanoma, and that depletion of MITF results in reduced HERV-K expression. In turn, experimentally depleting Rec in a proliferative melanoma cell line leads to lower mRNA levels of MITF and its predicted target genes. Furthermore, Rec knockdown leads to an upregulation of epithelial-to-mesenchymal associated genes and an enhanced invasion phenotype of proliferative melanoma cells. Together these results suggest the existence of a regulatory loop between MITF and Rec that may modulate the transition from proliferative to invasive stages of melanoma. Because HERV-K(HML2) elements are restricted to hominoid primates, these findings might explain certain species-specific features of melanoma progression and point to some limitations of animal models in melanoma studies.
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13
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Cardelli M, Doorn RV, Larcher L, Donato MD, Piacenza F, Pierpaoli E, Giacconi R, Malavolta M, Rachakonda S, Gruis NA, Molven A, Andresen PA, Pjanova D, van den Oord JJ, Provinciali M, Nagore E, Kumar R. Association of HERV-K and LINE-1 hypomethylation with reduced disease-free survival in melanoma patients. Epigenomics 2020; 12:1689-1706. [PMID: 33125285 DOI: 10.2217/epi-2020-0127] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: To evaluate CpG methylation of long interspersed nuclear elements 1 (LINE-1) and human endogenous retrovirus K (HERV-K) retroelements as potential prognostic biomarkers in cutaneous melanoma. Materials & methods: Methylation of HERV-K and LINE-1 retroelements was assessed in resected melanoma tissues from 82 patients ranging in age from 14 to 88 years. In addition, nevi from eight patients were included for comparison with nonmalignant melanocytic lesions. Results: Methylation levels were lower in melanomas than in nevi. HERV-K and LINE-1 methylation were decreased in melanoma patients with clinical parameters associated with adverse prognosis, while they were independent of age and gender. Hypomethylation of HERV-K (but not LINE-1) was an independent predictor of reduced disease-free survival. Conclusion: HERV-K hypomethylation can be a potential independent biomarker of melanoma recurrence.
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Affiliation(s)
- Maurizio Cardelli
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, 60121 Ancona, Italy
| | - Remco van Doorn
- Department of Dermatology, Leiden University Medical Center, 2300RC Leiden, The Netherlands
| | - Lares Larcher
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, 60121 Ancona, Italy
| | - Michela Di Donato
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, 60121 Ancona, Italy
| | - Francesco Piacenza
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, 60121 Ancona, Italy
| | - Elisa Pierpaoli
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, 60121 Ancona, Italy
| | - Robertina Giacconi
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, 60121 Ancona, Italy
| | - Marco Malavolta
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, 60121 Ancona, Italy
| | - Sivaramakrishna Rachakonda
- Division of Molecular Genetic Epidemiology, German Cancer Research Center, 69120 Heidelberg, Germany.,Division of Functional Genome Analysis, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Nelleke A Gruis
- Department of Dermatology, Leiden University Medical Center, 2300RC Leiden, The Netherlands
| | - Anders Molven
- Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, N-5020 Bergen, Norway.,Department of Pathology, Haukeland University Hospital, N-5021 Bergen, Norway
| | - Per Arne Andresen
- Department of Pathology, Oslo University Hospital, Rikshospitalet, 0424 Oslo, Norway
| | - Dace Pjanova
- Latvian Biomedical Research & Study Centre, LV-1067 Riga, Latvia
| | | | - Mauro Provinciali
- Advanced Technology Center for Aging Research, Scientific Technological Area, IRCCS INRCA, 60121 Ancona, Italy
| | - Eduardo Nagore
- Department of Dermatology, Instituto Valenciano de Oncología, 46009 València, Spain
| | - Rajiv Kumar
- Division of Molecular Genetic Epidemiology, German Cancer Research Center, 69120 Heidelberg, Germany.,Division of Functional Genome Analysis, German Cancer Research Center, 69120 Heidelberg, Germany
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14
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Human Endogenous Retrovirus K in Cancer: A Potential Biomarker and Immunotherapeutic Target. Viruses 2020; 12:v12070726. [PMID: 32640516 PMCID: PMC7412025 DOI: 10.3390/v12070726] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/26/2020] [Accepted: 06/29/2020] [Indexed: 12/16/2022] Open
Abstract
In diseases where epigenetic mechanisms are changed, such as cancer, many genes show altered gene expression and inhibited genes become activated. Human endogenous retrovirus type K (HERV-K) expression is usually inhibited in normal cells from healthy adults. In tumor cells, however, HERV-K mRNA expression has been frequently documented to increase. Importantly, HERV-K-derived proteins can act as tumor-specific antigens, a class of neoantigens, and induce immune responses in different types of cancer. In this review, we describe the function of the HERV-K HML-2 subtype in carcinogenesis as biomarkers, and their potential as targets for cancer immunotherapy.
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15
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Marasca F, Gasparotto E, Polimeni B, Vadalà R, Ranzani V, Bodega B. The Sophisticated Transcriptional Response Governed by Transposable Elements in Human Health and Disease. Int J Mol Sci 2020; 21:ijms21093201. [PMID: 32366056 PMCID: PMC7247572 DOI: 10.3390/ijms21093201] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 04/29/2020] [Accepted: 04/29/2020] [Indexed: 01/15/2023] Open
Abstract
Transposable elements (TEs), which cover ~45% of the human genome, although firstly considered as “selfish” DNA, are nowadays recognized as driving forces in eukaryotic genome evolution. This capability resides in generating a plethora of sophisticated RNA regulatory networks that influence the cell type specific transcriptome in health and disease. Indeed, TEs are transcribed and their RNAs mediate multi-layered transcriptional regulatory functions in cellular identity establishment, but also in the regulation of cellular plasticity and adaptability to environmental cues, as occurs in the immune response. Moreover, TEs transcriptional deregulation also evolved to promote pathogenesis, as in autoimmune and inflammatory diseases and cancers. Importantly, many of these findings have been achieved through the employment of Next Generation Sequencing (NGS) technologies and bioinformatic tools that are in continuous improvement to overcome the limitations of analyzing TEs sequences. However, they are highly homologous, and their annotation is still ambiguous. Here, we will review some of the most recent findings, questions and improvements to study at high resolution this intriguing portion of the human genome in health and diseases, opening the scenario to novel therapeutic opportunities.
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Affiliation(s)
- Federica Marasca
- Fondazione INGM, Istituto Nazionale di Genetica Molecolare “Enrica e Romeo Invernizzi”, 20122 Milan, Italy; (F.M.); (E.G.); (B.P.); (R.V.); (V.R.)
| | - Erica Gasparotto
- Fondazione INGM, Istituto Nazionale di Genetica Molecolare “Enrica e Romeo Invernizzi”, 20122 Milan, Italy; (F.M.); (E.G.); (B.P.); (R.V.); (V.R.)
| | - Benedetto Polimeni
- Fondazione INGM, Istituto Nazionale di Genetica Molecolare “Enrica e Romeo Invernizzi”, 20122 Milan, Italy; (F.M.); (E.G.); (B.P.); (R.V.); (V.R.)
| | - Rebecca Vadalà
- Fondazione INGM, Istituto Nazionale di Genetica Molecolare “Enrica e Romeo Invernizzi”, 20122 Milan, Italy; (F.M.); (E.G.); (B.P.); (R.V.); (V.R.)
- Translational and Molecular Medicine, DIMET, University of Milan-Bicocca, 20900 Monza, Italy
| | - Valeria Ranzani
- Fondazione INGM, Istituto Nazionale di Genetica Molecolare “Enrica e Romeo Invernizzi”, 20122 Milan, Italy; (F.M.); (E.G.); (B.P.); (R.V.); (V.R.)
| | - Beatrice Bodega
- Fondazione INGM, Istituto Nazionale di Genetica Molecolare “Enrica e Romeo Invernizzi”, 20122 Milan, Italy; (F.M.); (E.G.); (B.P.); (R.V.); (V.R.)
- Correspondence:
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16
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Moufarrij S, Srivastava A, Gomez S, Hadley M, Palmer E, Austin PT, Chisholm S, Diab N, Roche K, Yu A, Li J, Zhu W, Lopez-Acevedo M, Villagra A, Chiappinelli KB. Combining DNMT and HDAC6 inhibitors increases anti-tumor immune signaling and decreases tumor burden in ovarian cancer. Sci Rep 2020; 10:3470. [PMID: 32103105 PMCID: PMC7044433 DOI: 10.1038/s41598-020-60409-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 02/12/2020] [Indexed: 12/12/2022] Open
Abstract
Novel therapies are urgently needed for ovarian cancer, the deadliest gynecologic malignancy. Ovarian cancer has thus far been refractory to immunotherapies that stimulate the host immune system to recognize and kill cancer cells. This may be because of a suppressive tumor immune microenvironment and lack of recruitment and activation of immune cells that kill cancer cells. Our previous work showed that epigenetic drugs including DNA methyltransferase inhibitors and histone deacetylase 6 inhibitors (DNMTis and HDAC6is) individually increase immune signaling in cancer cells. We find that combining DNMTi and HDAC6i results in an amplified type I interferon response, leading to increased cytokine and chemokine expression and higher expression of the MHC I antigen presentation complex in human and mouse ovarian cancer cell lines. Treating mice bearing ID8 Trp53-/- ovarian cancer with HDAC6i/DNMTi led to an increase in tumor-killing cells such as IFNg+ CD8, NK, and NKT cells and a reversal of the immunosuppressive tumor microenvironment with a decrease in MDSCs and PD-1hi CD4 T cells, corresponding with an increase in survival. Thus combining the epigenetic modulators DNMTi and HDAC6i increases anti-tumor immune signaling from cancer cells and has beneficial effects on the ovarian tumor immune microenvironment.
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Affiliation(s)
- Sara Moufarrij
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA
- The Department of Obstetrics & Gynecology, The George Washington University, Washington, DC, USA
| | - Aneil Srivastava
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA
- The Department of Microbiology, Immunology, & Tropical Medicine, The George Washington University, Washington, DC, USA
| | - Stephanie Gomez
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA
- The Department of Microbiology, Immunology, & Tropical Medicine, The George Washington University, Washington, DC, USA
- The Institute for Biomedical Sciences, The George Washington University, Washington, DC, 20052, USA
| | - Melissa Hadley
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA
- The Department of Microbiology, Immunology, & Tropical Medicine, The George Washington University, Washington, DC, USA
| | - Erica Palmer
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA
- The Department of Biochemistry and Molecular Medicine, The George Washington University, Washington, DC, USA
| | - Paul Tran Austin
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA
- The Department of Microbiology, Immunology, & Tropical Medicine, The George Washington University, Washington, DC, USA
| | - Sarah Chisholm
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA
- The Department of Microbiology, Immunology, & Tropical Medicine, The George Washington University, Washington, DC, USA
| | - Noor Diab
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA
| | - Kyle Roche
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA
- The Department of Microbiology, Immunology, & Tropical Medicine, The George Washington University, Washington, DC, USA
| | - Angela Yu
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA
- The Department of Microbiology, Immunology, & Tropical Medicine, The George Washington University, Washington, DC, USA
| | - Jing Li
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA
- The Department of Biochemistry and Molecular Medicine, The George Washington University, Washington, DC, USA
| | - Wenge Zhu
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA
- The Department of Biochemistry and Molecular Medicine, The George Washington University, Washington, DC, USA
| | - Micael Lopez-Acevedo
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA
- The Department of Obstetrics & Gynecology, The George Washington University, Washington, DC, USA
| | - Alejandro Villagra
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA.
- The Department of Biochemistry and Molecular Medicine, The George Washington University, Washington, DC, USA.
| | - Katherine B Chiappinelli
- The George Washington University Cancer Center, The George Washington University, Washington, DC, USA.
- The Department of Microbiology, Immunology, & Tropical Medicine, The George Washington University, Washington, DC, USA.
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17
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Tavakolian S, Goudarzi H, Lak E, Faghihloo E. The evaluation of HERV-K env, np9, rec, gag expression in normal, polyp and cancerous tissues of gastric and colon. Future Virol 2019. [DOI: 10.2217/fvl-2019-0114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Aim: Gastrointestinal cancer is one of the most alarming cancers worldwide. Infections exert an impact on tumor progression in gastrointestinal tissues. The alteration in the expression of human endogenous retrovirus-K ( HERV-K) genes could remarkably induce oncogenic activity. Materials & methods: In 22 gastric and 23 colon cancer patients, the expression level of HERV-K env, rec, gag and np9 were evaluated. Results: While there was a slight increase in the expression of HERV-K env in colon cancer tissues, the expression level of this gene decreased in gastric tissues. Moreover, the expression of both np9 and gag HERV-K were upregulated only in colon cancer. Nevertheless, rec HERV-K was downregulated in gastric cancer tissues. Conclusion: HERV-K-associated genes can be used as a possible biomarker for cancers diagnosis.
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Affiliation(s)
- Shaian Tavakolian
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Goudarzi
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Elena Lak
- Department of gastric & liver, Emam Hossein hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ebrahim Faghihloo
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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18
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Approaches to treat immune hot, altered and cold tumours with combination immunotherapies. Nat Rev Drug Discov 2019; 18:197-218. [PMID: 30610226 DOI: 10.1038/s41573-018-0007-y] [Citation(s) in RCA: 1861] [Impact Index Per Article: 372.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Immunotherapies are the most rapidly growing drug class and have a major impact in oncology and on human health. It is increasingly clear that the effectiveness of immunomodulatory strategies depends on the presence of a baseline immune response and on unleashing of pre-existing immunity. Therefore, a general consensus emerged on the central part played by effector T cells in the antitumour responses. Recent technological, analytical and mechanistic advances in immunology have enabled the identification of patients who are more likely to respond to immunotherapy. In this Review, we focus on defining hot, altered and cold tumours, the complexity of the tumour microenvironment, the Immunoscore and immune contexture of tumours, and we describe approaches to treat such tumours with combination immunotherapies, including checkpoint inhibitors. In the upcoming era of combination immunotherapy, it is becoming critical to understand the mechanisms responsible for hot, altered or cold immune tumours in order to boost a weak antitumour immunity. The impact of combination therapy on the immune response to convert an immune cold into a hot tumour will be discussed.
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19
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Kim S, Ku Y, Ku J, Kim Y. Evidence of Aberrant Immune Response by Endogenous Double-Stranded RNAs: Attack from Within. Bioessays 2019; 41:e1900023. [PMID: 31099409 DOI: 10.1002/bies.201900023] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/15/2019] [Indexed: 12/17/2022]
Abstract
Many innate immune response proteins recognize foreign nucleic acids from invading pathogens to initiate antiviral signaling. These proteins mostly rely on structural characteristics of the nucleic acids rather than their specific sequences to distinguish self and nonself. One feature utilized by RNA sensors is the extended stretch of double-stranded RNA (dsRNA) base pairs. However, the criteria for recognizing nonself dsRNAs are rather lenient, and hairpin structure of self-RNAs can also trigger an immune response. Consequently, aberrant activation of RNA sensors has been reported in numerous human diseases. Yet, in most cases, the activating antigens remain unknown. Recent studies have developed sequencing techniques tailored to specifically capture dsRNAs and identified that various noncoding elements in the nuclear and the mitochondrial genome can generate dsRNAs. Here, the identity of endogenous dsRNAs, their recognition by dsRNA sensors, and their implications in the pathogenesis of human diseases ranging from inflammatory to degenerative are presented.
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Affiliation(s)
- Sujin Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,KI for Health Science and Technology (KIHST), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Yongsuk Ku
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,KI for Health Science and Technology (KIHST), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Jayoung Ku
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,KI for Health Science and Technology (KIHST), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Yoosik Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,KI for Health Science and Technology (KIHST), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
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20
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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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21
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Smith CC, Beckermann KE, Bortone DS, De Cubas AA, Bixby LM, Lee SJ, Panda A, Ganesan S, Bhanot G, Wallen EM, Milowsky MI, Kim WY, Rathmell WK, Swanstrom R, Parker JS, Serody JS, Selitsky SR, Vincent BG. Endogenous retroviral signatures predict immunotherapy response in clear cell renal cell carcinoma. J Clin Invest 2018; 128:4804-4820. [PMID: 30137025 PMCID: PMC6205406 DOI: 10.1172/jci121476] [Citation(s) in RCA: 186] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 08/10/2018] [Indexed: 12/27/2022] Open
Abstract
Human endogenous retroviruses (hERVs) are remnants of exogenous retroviruses that have integrated into the genome throughout evolution. We developed a computational workflow, hervQuant, which identified more than 3,000 transcriptionally active hERVs within The Cancer Genome Atlas (TCGA) pan-cancer RNA-Seq database. hERV expression was associated with clinical prognosis in several tumor types, most significantly clear cell renal cell carcinoma (ccRCC). We explored two mechanisms by which hERV expression may influence the tumor immune microenvironment in ccRCC: (i) RIG-I-like signaling and (ii) retroviral antigen activation of adaptive immunity. We demonstrated the ability of hERV signatures associated with these immune mechanisms to predict patient survival in ccRCC, independent of clinical staging and molecular subtyping. We identified potential tumor-specific hERV epitopes with evidence of translational activity through the use of a ccRCC ribosome profiling (Ribo-Seq) dataset, validated their ability to bind HLA in vitro, and identified the presence of MHC tetramer-positive T cells against predicted epitopes. hERV sequences identified through this screening approach were significantly more highly expressed in ccRCC tumors responsive to treatment with programmed death receptor 1 (PD-1) inhibition. hervQuant provides insights into the role of hERVs within the tumor immune microenvironment, as well as evidence that hERV expression could serve as a biomarker for patient prognosis and response to immunotherapy.
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Affiliation(s)
- Christof C. Smith
- Department of Microbiology and Immunology, UNC School of Medicine, Chapel Hill, North Carolina, USA.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Kathryn E. Beckermann
- Division of Hematology and Oncology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Dante S. Bortone
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Lineberger Bioinformatics Group, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Aguirre A. De Cubas
- Division of Hematology and Oncology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Lisa M. Bixby
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Samuel J. Lee
- Department of Microbiology and Immunology, UNC School of Medicine, Chapel Hill, North Carolina, USA.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Anshuman Panda
- Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey, USA; and Department of Physics, Rutgers University, Piscataway, New Jersey, USA
| | - Shridar Ganesan
- Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey, USA; and Department of Physics, Rutgers University, Piscataway, New Jersey, USA
| | - Gyan Bhanot
- Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey, USA; and Department of Physics, Rutgers University, Piscataway, New Jersey, USA
| | - Eric M. Wallen
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Urology
| | - Matthew I. Milowsky
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Division of Hematology/Oncology, Department of Medicine
| | - William Y. Kim
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Urology,,Division of Hematology/Oncology, Department of Medicine,,Department of Genetics
| | - W. Kimryn Rathmell
- Division of Hematology and Oncology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Ronald Swanstrom
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Biochemistry and Biophysics, and
| | - Joel S. Parker
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Lineberger Bioinformatics Group, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Department of Genetics
| | - Jonathan S. Serody
- Department of Microbiology and Immunology, UNC School of Medicine, Chapel Hill, North Carolina, USA.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Division of Hematology/Oncology, Department of Medicine
| | - Sara R. Selitsky
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Lineberger Bioinformatics Group, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Benjamin G. Vincent
- Department of Microbiology and Immunology, UNC School of Medicine, Chapel Hill, North Carolina, USA.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.,Division of Hematology/Oncology, Department of Medicine,,Curriculum in Bioinformatics and Computational Biology, UNC School of Medicine, Chapel Hill, North Carolina, USA
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22
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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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23
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Montesion M, Williams ZH, Subramanian RP, Kuperwasser C, Coffin JM. Promoter expression of HERV-K (HML-2) provirus-derived sequences is related to LTR sequence variation and polymorphic transcription factor binding sites. Retrovirology 2018; 15:57. [PMID: 30126415 PMCID: PMC6102855 DOI: 10.1186/s12977-018-0441-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Accepted: 08/13/2018] [Indexed: 12/29/2022] Open
Abstract
Background Increased transcription of the human endogenous retrovirus group HERV-K (HML-2) is often seen during disease. Although the mechanism of its tissue-specific activation is unclear, research shows that LTR CpG hypomethylation alone is not sufficient to induce its promoter activity and that the transcriptional milieu of a malignant cell contributes, at least partly, to differential HML-2 expression. Results We analyzed the relationship between LTR sequence variation and promoter expression patterns in human breast cancer cell lines, finding them to be positively correlated. In particular, two proviruses (3q12.3 and 11p15.4) displayed increased activity in almost all tumorigenic cell lines sampled. Using a transcription factor binding site prediction algorithm, we identified two unique binding sites in each 5′ LTR that appeared to be associated with inducing promoter activity during neoplasia. Genomic analysis of the homologous proviruses in several non-human primates indicated post-integration genetic drift in two transcription factor binding sites, away from the ancestral sequence and towards the active form. Based on the sequences of 2504 individuals from the 1000 Genomes Project, the active form of the 11p15.4 site was found to be polymorphic within the human population, with an allele frequency of 51%, whereas the activating mutation in the 3q12.3 provirus was fixed in humans but not present in the orthologous provirus in chimpanzees or gorillas. Conclusions These data suggest that stage-specific transcription factors at least partly contribute to LTR promoter activity during transformation and that, in some cases, transcription factor binding site polymorphisms may be responsible for the differential HML-2 expression often seen between individuals. Electronic supplementary material The online version of this article (10.1186/s12977-018-0441-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Meagan Montesion
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.,Foundation Medicine, Inc., Cambridge, MA, USA
| | - Zachary H Williams
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
| | - Ravi P Subramanian
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.,Excerpta Medica, New York, NY, USA
| | - Charlotte Kuperwasser
- Department of Developmental, Chemical, and Molecular Biology, Tufts University School of Medicine, Boston, MA, USA.,Raymond and Beverly Sackler Convergence Laboratory, Tufts University School of Medicine, Boston, MA, USA
| | - John M Coffin
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.
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24
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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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25
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Anderson M, Kashanchi F, Jacobson S. Role of Exosomes in Human Retroviral Mediated Disorders. J Neuroimmune Pharmacol 2018; 13:279-291. [PMID: 29656370 DOI: 10.1007/s11481-018-9784-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 03/15/2018] [Indexed: 02/07/2023]
Abstract
Retroviruses comprise an ancient and varied group of viruses with the unique ability to integrate DNA from an RNA transcript into the genome, a subset of which are able to integrate in humans. The timing of these integrations during human history has dictated whether these viruses have remained exogenous and given rise to various human diseases or have become inseparable from the host genome (endogenous retroviruses). Given the ability of retroviruses to integrate into the host and subsequently co-opt host cellular process for viral propagation, retroviruses have been shown to be closely associated with several cellular processes including exosome formation. Exosomes are 30-150 nm unilamellar extracellular vesicles that originate from intraluminal vesicles (ILVs) that form in the endosomal compartment. Exosomes have been shown to be important in intercellular communication and immune cell function. Almost every cell type studied has been shown to produce these types of vesicles, with the cell type dictating the contents, which include proteins, mRNA, and miRNAs. Importantly, recent evidence has shown that infection by viruses, including retroviruses, alter the contents and subsequent function of produced exosomes. In this review, we will discuss the important retroviruses associated with human health and disease. Furthermore, we will delve into the impact of exosome formation and manipulation by integrated retroviruses on human health, survival, and human retroviral disease pathogenesis.
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Affiliation(s)
- Monique Anderson
- National Institute of Neurological Disorders and Stroke, Neuroimmunology Branch, Viral Immunology Section, National Institutes of Health, Bethesda, MD, 20892, USA. .,Department of Pathology, Molecular and Cellular Basis of Disease Graduate Program, University of Virginia School of Medicine, Charlottesville, VA, 22903, USA.
| | - Fatah Kashanchi
- National Center for Biodefense and Infectious Disease, Laboratory of Molecular Virology, George Mason University, Manassas, VA, 20110, USA
| | - Steven Jacobson
- National Institute of Neurological Disorders and Stroke, Neuroimmunology Branch, Viral Immunology Section, National Institutes of Health, Bethesda, MD, 20892, USA
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26
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Bergallo M, Daprà V, Novelli M, Rassu M, Montanari P, Galliano I, Quaglino P, Fierro MT. Is HERV-K and HERV-W expression regulated by mir-155 in Sézary Syndrome? GIORN ITAL DERMAT V 2018; 155:477-482. [PMID: 29582620 DOI: 10.23736/s0392-0488.18.05897-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND According to the latest update, 2578 unique mature miRNAs are currently annotated in the human genome and participate in the regulation of multiple events, such as cellular proliferation or apoptosis. A previous study analyzing global miRNA expression patterns in GH cells (high HERV-K versus low) showed that two miRNAs (miR-663 and miR-638) are differentially regulated and exhibit expression parallel to that of HERV-K. The aim of this study was to evaluate HERV-K and -W pol gene and mir-155 expression in SS patients and possible relationship between them. METHODS The comparison between SS patients and healthy donor showed a significant difference in terms of mir-155 expression P=0.0003 as previously reported by our groups. RESULTS We demonstrated that HERV-K and -W pol gene expression was significantly higher in SS patients vs. healthy donor as previously reported by our groups. Our correlation data suggest that miR-155 are not directly involved in regulating the HERVs. CONCLUSIONS Furthermore, further studies including other cohorts of pathology with mir-155 and HERVs involvement such as inflammatory diseases are needed to investigate the role of mir-155 in the cross-activations of HERVs.
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Affiliation(s)
- Massimiliano Bergallo
- Department of Public Health and Pediatric Sciences, Medical School, University of Turin, Turin, Italy -
| | - Valentina Daprà
- Department of Public Health and Pediatric Sciences, Medical School, University of Turin, Turin, Italy
| | - Mauro Novelli
- Section of Dermatology, Department of Medical Sciences, University of Turin, Turin, Italy
| | - Marco Rassu
- Department of Public Health and Pediatric Sciences, Medical School, University of Turin, Turin, Italy
| | - Paola Montanari
- Department of Public Health and Pediatric Sciences, Medical School, University of Turin, Turin, Italy
| | - Ilaria Galliano
- Department of Public Health and Pediatric Sciences, Medical School, University of Turin, Turin, Italy
| | - Pietro Quaglino
- Section of Dermatology, Department of Medical Sciences, University of Turin, Turin, Italy
| | - Maria T Fierro
- Section of Dermatology, Department of Medical Sciences, University of Turin, Turin, Italy
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27
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Bannert N, Hofmann H, Block A, Hohn O. HERVs New Role in Cancer: From Accused Perpetrators to Cheerful Protectors. Front Microbiol 2018; 9:178. [PMID: 29487579 PMCID: PMC5816757 DOI: 10.3389/fmicb.2018.00178] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 01/25/2018] [Indexed: 02/02/2023] Open
Abstract
Initial indications that retroviruses are connected to neoplastic transformation were seen more than a century ago. This concept has also been tested for endogenized retroviruses (ERVs) that are abundantly expressed in many transformed cells. In healthy cells, ERV expression is commonly prevented by DNA methylation and other epigenetic control mechanisms. ERVs are remnants of former exogenous forms that invaded the germ line of the host and have since been vertically transmitted. Several examples of ERV-induced genomic recombination events and dysregulation of cellular genes that contribute to tumor formation have been well documented. Moreover, evidence is accumulating that certain ERV proteins have oncogenic properties. In contrast to these implications for supporting cancer induction, a recent string of papers has described favorable outcomes of increasing human ERV (HERV) RNA and DNA abundance by treatment of cancer cells with methyltransferase inhibitors. Analogous to an infecting agent, the ERV-derived nucleic acids are sensed in the cytoplasm and activate innate immune responses that drive the tumor cell into apoptosis. This "viral mimicry" induced by epigenetic drugs might offer novel therapeutic approaches to help target cancer cells that are normally difficult to treat using standard chemotherapy. In this review, we discuss both the detrimental and the new beneficial role of HERV reactivation in terms of its implications for cancer.
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Affiliation(s)
- Norbert Bannert
- HIV and Other Retroviruses, Robert Koch Institute, Berlin, Germany
| | - Henning Hofmann
- HIV and Other Retroviruses, Robert Koch Institute, Berlin, Germany
| | - Adriana Block
- HIV and Other Retroviruses, Robert Koch Institute, Berlin, Germany
| | - Oliver Hohn
- HIV and Other Retroviruses, Robert Koch Institute, Berlin, Germany
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28
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Topper MJ, Vaz M, Chiappinelli KB, DeStefano Shields CE, Niknafs N, Yen RWC, Wenzel A, Hicks J, Ballew M, Stone M, Tran PT, Zahnow CA, Hellmann MD, Anagnostou V, Strissel PL, Strick R, Velculescu VE, Baylin SB. Epigenetic Therapy Ties MYC Depletion to Reversing Immune Evasion and Treating Lung Cancer. Cell 2017; 171:1284-1300.e21. [PMID: 29195073 DOI: 10.1016/j.cell.2017.10.022] [Citation(s) in RCA: 311] [Impact Index Per Article: 44.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 08/07/2017] [Accepted: 10/13/2017] [Indexed: 12/25/2022]
Abstract
Combining DNA-demethylating agents (DNA methyltransferase inhibitors [DNMTis]) with histone deacetylase inhibitors (HDACis) holds promise for enhancing cancer immune therapy. Herein, pharmacologic and isoform specificity of HDACis are investigated to guide their addition to a DNMTi, thus devising a new, low-dose, sequential regimen that imparts a robust anti-tumor effect for non-small-cell lung cancer (NSCLC). Using in-vitro-treated NSCLC cell lines, we elucidate an interferon α/β-based transcriptional program with accompanying upregulation of antigen presentation machinery, mediated in part through double-stranded RNA (dsRNA) induction. This is accompanied by suppression of MYC signaling and an increase in the T cell chemoattractant CCL5. Use of this combination treatment schema in mouse models of NSCLC reverses tumor immune evasion and modulates T cell exhaustion state towards memory and effector T cell phenotypes. Key correlative science metrics emerge for an upcoming clinical trial, testing enhancement of immune checkpoint therapy for NSCLC.
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Affiliation(s)
- Michael J Topper
- Department of Oncology, The Johns Hopkins School of Medicine, The Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287, USA; The Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Michelle Vaz
- Department of Oncology, The Johns Hopkins School of Medicine, The Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287, USA
| | - Katherine B Chiappinelli
- Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University Cancer Center, Washington, DC 20052, USA
| | - Christina E DeStefano Shields
- Department of Oncology, The Johns Hopkins School of Medicine, The Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287, USA
| | - Noushin Niknafs
- Department of Oncology, The Johns Hopkins School of Medicine, The Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287, USA
| | - Ray-Whay Chiu Yen
- Department of Oncology, The Johns Hopkins School of Medicine, The Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287, USA
| | - Alyssa Wenzel
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jessica Hicks
- Department of Urologic Pathology, The Johns Hopkins School of Medicine, The Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287, USA
| | - Matthew Ballew
- Department of Radiation Oncology & Molecular Radiation Sciences, The Johns Hopkins School of Medicine, The Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287, USA
| | - Meredith Stone
- Department of Oncology, The Johns Hopkins School of Medicine, The Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287, USA; The Graduate Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Phuoc T Tran
- Department of Radiation Oncology & Molecular Radiation Sciences, The Johns Hopkins School of Medicine, The Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287, USA
| | - Cynthia A Zahnow
- Department of Oncology, The Johns Hopkins School of Medicine, The Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287, USA
| | - Matthew D Hellmann
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Valsamo Anagnostou
- Department of Oncology, The Johns Hopkins School of Medicine, The Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287, USA
| | - Pamela L Strissel
- Department of Gynecology and Obstetrics, Laboratory for Molecular Medicine, University-Clinic Erlangen, 91054 Erlangen, Germany
| | - Reiner Strick
- Department of Gynecology and Obstetrics, Laboratory for Molecular Medicine, University-Clinic Erlangen, 91054 Erlangen, Germany
| | - Victor E Velculescu
- Department of Oncology, The Johns Hopkins School of Medicine, The Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287, USA
| | - Stephen B Baylin
- Department of Oncology, The Johns Hopkins School of Medicine, The Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD 21287, USA.
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29
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Bourneuf E. The MeLiM Minipig: An Original Spontaneous Model to Explore Cutaneous Melanoma Genetic Basis. Front Genet 2017; 8:146. [PMID: 29081790 PMCID: PMC5645500 DOI: 10.3389/fgene.2017.00146] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/25/2017] [Indexed: 12/19/2022] Open
Abstract
Melanoma is the deadliest skin cancer and is a major public health concern with a growing incidence worldwide. As for other complex diseases, animal models are needed in order to better understand the mechanisms leading to pathology, identify potential biomarkers to be used in the clinics, and eventually molecular targets for therapeutic solutions. Cutaneous melanoma, arising from skin melanocytes, is mainly caused by environmental factors such as UV radiation; however a significant genetic component participates in the etiology of the disease. The pig is a recognized model for spontaneous development of melanoma with features similar to the human ones, followed by a complete regression and a vitiligo-like depigmentation. Three different pig models (MeLiM, Sinclair, and MMS-Troll) have been maintained through the last decades, and different genetic studies have evidenced a complex inheritance of the disease. As in humans, pigmentation seems to play a prominent role, notably through MC1R and MITF signaling. Conversely, cell cycle genes as CDKN2A and CDK4 have been excluded as predisposing for melanoma in MeLiM. So far, only sparse studies have focused on somatic changes occurring during oncogenesis, and have revealed major cytological changes and a potential dysfunction of the telomere maintenance system. Finally, the spontaneous tumor progression and regression occurring in these models could shed light on the interplay between endogenous retroviruses, melanomagenesis, and adaptive immune response.
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Affiliation(s)
- Emmanuelle Bourneuf
- LREG, CEA, Université Paris-Saclay, Jouy-en-Josas, France.,GABI, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
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30
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DEMETER plant DNA demethylase induces antiviral response by interferon signalling in animal cells. Sci Rep 2017; 7:9160. [PMID: 28831075 PMCID: PMC5567224 DOI: 10.1038/s41598-017-08827-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/17/2017] [Indexed: 12/20/2022] Open
Abstract
DNA methylation is a prominent epigenetic modification in plants and animals regulated by similar mechanisms but the process of DNA demethylation is profoundly different. Unlike vertebrates that require a series of enzymatic conversions of 5-methylcytosine (5mC) into other bases for DNA demethylation, plants utilize the DEMETER (DME) family of 5mC DNA glycosylases to catalyze a direct removal of 5mC from DNA. Here we introduced Arabidopsis DME into human HEK-293T cells to allow direct 5mC excision, and observed that direct DNA demethylation activity was successfully implemented by DME expression. In addition, DME induced diverse cellular responses such as cell proliferation inhibition, cell cycle dysregulation and S phase arrest. Microarray and methylome analyses revealed that DME upregulated a number of genes including cell cycle components, heat shock proteins, and notably, various interferon-stimulated genes. Moreover, DME-mediated DNA demethylation activated endogenous repeat elements, which are likely to form dsRNAs as viral mimics and eventually trigger interferon cascades to establish the antiviral state. This work demonstrates that plant DNA demethylase catalyzes DNA demethylation with a bypass of initial base conversion steps, and the interferon signaling plays a pivotal role to alleviate genotoxic stresses associated with DME-induced DNA demethylation in mammalian cells.
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31
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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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32
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Hurst TP, Magiorkinis G. Epigenetic Control of Human Endogenous Retrovirus Expression: Focus on Regulation of Long-Terminal Repeats (LTRs). Viruses 2017; 9:v9060130. [PMID: 28561791 PMCID: PMC5490807 DOI: 10.3390/v9060130] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 05/22/2017] [Accepted: 05/22/2017] [Indexed: 12/25/2022] Open
Abstract
Transposable elements, including endogenous retroviruses (ERVs), comprise almost 45% of the human genome. This could represent a significant pathogenic burden but it is becoming more evident that many of these elements have a positive contribution to make to normal human physiology. In particular, the contributions of human ERVs (HERVs) to gene regulation and the expression of noncoding RNAs has been revealed with the help of new and emerging genomic technologies. HERVs have the common provirus structure of coding open reading frames (ORFs) flanked by two long-terminal repeats (LTRs). However, over the course of evolution and as a consequence of host defence mechanisms, most of the sequences contain INDELs, mutations or have been reduced to single LTRs by recombination. These INDELs and mutations reduce HERV activity. However, there is a trade-off for the host cells in that HERVs can provide beneficial sources of genetic variation but with this benefit comes the risk of pathogenic activity and spread within the genome. For example, the LTRs are of critical importance as they contain promoter sequences and can regulate not only HERV expression but that of human genes. This is true even when the LTRs are located in intergenic regions or are in antisense orientation to the rest of the gene. Uncontrolled, this promoter activity could disrupt normal gene expression or transcript processing (e.g., splicing). Thus, control of HERVs and particularly their LTRs is essential for the cell to manage these elements and this control is achieved at multiple levels, including epigenetic regulations that permit HERV expression in the germline but silence it in most somatic tissues. We will discuss some of the common epigenetic mechanisms and how they affect HERV expression, providing detailed discussions of HERVs in stem cell, placenta and cancer biology.
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Affiliation(s)
- Tara P Hurst
- Department of Zoology, University of Oxford, Oxford OX1 3PS, UK.
| | - Gkikas Magiorkinis
- Department of Zoology, University of Oxford, Oxford OX1 3PS, UK.
- Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece.
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33
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Dunn J, Rao S. Epigenetics and immunotherapy: The current state of play. Mol Immunol 2017; 87:227-239. [PMID: 28511092 DOI: 10.1016/j.molimm.2017.04.012] [Citation(s) in RCA: 143] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 04/14/2017] [Accepted: 04/22/2017] [Indexed: 12/14/2022]
Abstract
Cancer cells employ a number of mechanisms to escape immunosurveillance and facilitate tumour progression. The recent explosion of interest in immunotherapy, especially immune checkpoint blockade, is a result of discoveries about the fundamental ligand-receptor interactions that occur between immune and cancer cells within the tumour microenvironment. Distinct ligands expressed by cancer cells engage with cell surface receptors on immune cells, triggering inhibitory pathways (such as PD-1/PD-L1) that render immune cells immunologically tolerant. Importantly, recent studies on the role of epigenetics in immune evasion have exposed a key role for epigenetic modulators in augmenting the tumour microenvironment and restoring immune recognition and immunogenicity. Epigenetic drugs such as DNA methyltransferase and histone deacetylase inhibitors can reverse immune suppression via several mechanisms such as enhancing expression of tumour-associated antigens, components of the antigen processing and presenting machinery pathways, immune checkpoint inhibitors, chemokines, and other immune-related genes. These discoveries have established a highly promising basis for studies using combined epigenetic and immunotherapeutic agents as anti-cancer therapies. In this review, we discuss the exciting role of epigenetic immunomodulation in tumour immune escape, emphasising its significance in priming and sensitising the host immune system to immunotherapies through mechanisms such as the activation of the viral defence pathway. With this background in mind, we highlight the promise of combined epigenetic therapy and immunotherapy, focusing on immune checkpoint blockade, to improve outcomes for patients with many different cancer types.
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Affiliation(s)
- Jennifer Dunn
- Health Research Institute, Faculty of Education, Science, Technology and Mathematics, University of Canberra, Bruce, ACT, 2601, Australia.
| | - Sudha Rao
- Health Research Institute, Faculty of Education, Science, Technology and Mathematics, University of Canberra, Bruce, ACT, 2601, Australia.
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34
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Wolff F, Leisch M, Greil R, Risch A, Pleyer L. The double-edged sword of (re)expression of genes by hypomethylating agents: from viral mimicry to exploitation as priming agents for targeted immune checkpoint modulation. Cell Commun Signal 2017; 15:13. [PMID: 28359286 PMCID: PMC5374693 DOI: 10.1186/s12964-017-0168-z] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/21/2017] [Indexed: 12/20/2022] Open
Abstract
Hypomethylating agents (HMAs) have been widely used over the last decade, approved for use in myelodysplastic syndrome (MDS), chronic myelomonocytic leukemia (CMML) and acute myeloid leukemia (AML). The proposed central mechanism of action of HMAs, is the reversal of aberrant methylation in tumor cells, thus reactivating CpG-island promoters and leading to (re)expression of tumor suppressor genes. Recent investigations into the mode of action of azacitidine (AZA) and decitabine (DAC) have revealed new molecular mechanisms that impinge on tumor immunity via induction of an interferon response, through activation of endogenous retroviral elements (ERVs) that are normally epigenetically silenced. Although the global demethylation of DNA by HMAs can induce anti-tumor effects, it can also upregulate the expression of inhibitory immune checkpoint receptors and their ligands, resulting in secondary resistance to HMAs. Recent studies have, however, suggested that this could be exploited to prime or (re)sensitize tumors to immune checkpoint inhibitor therapies. In recent years, immune checkpoints have been targeted by novel therapies, with the aim of (re)activating the host immune system to specifically eliminate malignant cells. Antibodies blocking checkpoint receptors have been FDA-approved for some solid tumors and a plethora of clinical trials testing these and other checkpoint inhibitors are under way. This review will discuss AZA and DAC novel mechanisms of action resulting from the re-expression of pathologically hypermethylated promoters of gene sets that are related to interferon signaling, antigen presentation and inflammation. We also review new insights into the molecular mechanisms of action of transient, low-dose HMAs on various tumor types and discuss the potential of new treatment options and combinations.
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Affiliation(s)
- Florian Wolff
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - Michael Leisch
- 3rd Medical Department with Hematology and Medical Oncology, Hemostaseology, Rheumatology and Infectious Diseases, Laboratory for Immunological and Molecular Cancer Research, Oncologic Center, Paracelsus Medical University Salzburg, Müllner Hauptstraße 48, A-5020, Salzburg, Austria
| | - Richard Greil
- 3rd Medical Department with Hematology and Medical Oncology, Hemostaseology, Rheumatology and Infectious Diseases, Laboratory for Immunological and Molecular Cancer Research, Oncologic Center, Paracelsus Medical University Salzburg, Müllner Hauptstraße 48, A-5020, Salzburg, Austria.,Salzburg Cancer Research Institute - Center for Clinical Cancer and Immunology Trials, Salzburg, Austria.,Cancer Cluster Salzburg, Salzburg, Austria
| | - Angela Risch
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria.,Cancer Cluster Salzburg, Salzburg, Austria
| | - Lisa Pleyer
- 3rd Medical Department with Hematology and Medical Oncology, Hemostaseology, Rheumatology and Infectious Diseases, Laboratory for Immunological and Molecular Cancer Research, Oncologic Center, Paracelsus Medical University Salzburg, Müllner Hauptstraße 48, A-5020, Salzburg, Austria. .,Salzburg Cancer Research Institute - Center for Clinical Cancer and Immunology Trials, Salzburg, Austria. .,Cancer Cluster Salzburg, Salzburg, Austria.
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Benešová M, Trejbalová K, Kovářová D, Vernerová Z, Hron T, Kučerová D, Hejnar J. DNA hypomethylation and aberrant expression of the human endogenous retrovirus ERVWE1/syncytin-1 in seminomas. Retrovirology 2017; 14:20. [PMID: 28302141 PMCID: PMC5356313 DOI: 10.1186/s12977-017-0342-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 03/03/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Syncytin-1 and 2, human fusogenic glycoproteins encoded by the env genes of the endogenous retroviral loci ERVWE1 and ERVFRDE1, respectively, contribute to the differentiation of multinucleated syncytiotrophoblast in chorionic villi. In non-trophoblastic cells, however, the expression of syncytins has to be suppressed to avoid potential pathogenic effects. Previously, we have shown that the transcriptional suppression of ERVWE1 promoter is controlled epigenetically by DNA methylation and chromatin modifications. In this study, we describe the aberrant expression of syncytin-1 in biopsies of testicular germ cell tumors. RESULTS We found efficient expression and splicing of syncytin-1 in seminomas and mixed germ cell tumors with seminoma component. Although another fusogenic gene, syncytin-2 was also derepressed in seminomas, its expression was significantly lower than that of syncytin-1. Neither the transcription factor GCM1 nor the increased copy number of ERVWE1 were sufficient for this aberrant expression of syncytin-1 in seminomas. In accordance with our recent finding of the highly increased expression of TET1 dioxygenase in most seminomas, the ERVWE1 promoter was significantly hypomethylated in comparison with the matched controls. In contrast, 5-hydroxymethylcytosine levels were not detectable at the ERVWE1 promoter. We further describe that another endogenous retroviral element adjacent to ERVWE1 remains transcriptionally suppressed and two additional HERV-W family members are only slightly upregulated in seminomas. CONCLUSIONS We conclude that DNA demethylation of the ERVWE1 promoter in seminomas is a prerequisite for syncytin-1 derepression. We propose the spliced syncytin-1 expression as a marker of seminoma and suggest that aberrant expression of endogenous retroviruses might be a correlate of the hypomethylated genome of seminomas.
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Affiliation(s)
- Martina Benešová
- Institute of Molecular Genetics, Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Kateřina Trejbalová
- Institute of Molecular Genetics, Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic.
| | - Denisa Kovářová
- Institute of Molecular Genetics, Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Zdenka Vernerová
- Department of Pathology, Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Tomáš Hron
- Institute of Molecular Genetics, Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Dana Kučerová
- Institute of Molecular Genetics, Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic
| | - Jiří Hejnar
- Institute of Molecular Genetics, Czech Academy of Sciences, Videnska 1083, 14220, Prague 4, Czech Republic.
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Argaw-Denboba A, Balestrieri E, Serafino A, Cipriani C, Bucci I, Sorrentino R, Sciamanna I, Gambacurta A, Sinibaldi-Vallebona P, Matteucci C. HERV-K activation is strictly required to sustain CD133+ melanoma cells with stemness features. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2017; 36:20. [PMID: 28125999 PMCID: PMC5270369 DOI: 10.1186/s13046-016-0485-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 12/27/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Melanoma is a heterogeneous tumor in which phenotype-switching and CD133 marker have been associated with metastasis promotion and chemotherapy resistance. CD133 positive (CD133+) subpopulation has also been suggested as putative cancer stem cell (CSC) of melanoma tumor. Human endogenous retrovirus type K (HERV-K) has been described to be aberrantly activated during melanoma progression and implicated in the etiopathogenesis of disease. Earlier, we reported that stress-induced HERV-K activation promotes cell malignant transformation and reduces the immunogenicity of melanoma cells. Herein, we investigated the correlation between HERV-K and the CD133+ melanoma cells during microenvironmental modifications. METHODS TVM-A12 cell line, isolated in our laboratory from a primary human melanoma lesion, and other commercial melanoma cell lines (G-361, WM-115, WM-266-4 and A375) were grown and maintained in the standard and stem cell media. RNA interference, Real-time PCR, flow cytometry analysis, self-renewal and migration/invasion assays were performed to characterize cell behavior and HERV-K expression. RESULTS Melanoma cells, exposed to stem cell media, undergo phenotype-switching and expansion of CD133+ melanoma cells, concomitantly promoted by HERV-K activation. Notably, the sorted CD133+ subpopulation showed stemness features, characterized by higher self-renewal ability, embryonic genes expression, migration and invasion capacities compared to the parental cell line. RNA interference-mediated downregulation experiments showed that HERV-K has a decisive role to expand and maintain the CD133+ melanoma subpopulation during microenvironmental modifications. Similarly, non nucleoside reverse transcriptase inhibitors (NNRTIs) efavirenz and nevirapine were effective to restrain the activation of HERV-K in melanoma cells, to antagonize CD133+ subpopulation expansion and to induce selective high level apoptosis in CD133+ cells. CONCLUSIONS HERV-K activation promotes melanoma cells phenotype-switching and is strictly required to expand and maintain the CD133+ melanoma cells with stemness features in response to microenvironmental modifications.
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Affiliation(s)
- Ayele Argaw-Denboba
- 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
| | - Annalucia Serafino
- Institute of Translational Pharmacology, National Research Council, Via Fosso del Cavaliere 100, 00133, Rome, Italy
| | - Chiara Cipriani
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy
| | - Ilaria Bucci
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy
| | - Roberta Sorrentino
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy
| | - Ilaria Sciamanna
- S.B.G.S.A. Istituto Superiore di Sanità (Italian National Institute of Health), Viale Regina Elena 299, 00161, Rome, Italy
| | - Alessandra Gambacurta
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier 1, 00133, 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
| | - Claudia Matteucci
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy.
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A New Molecular Mechanism Underlying the Antitumor Effect of DNA Methylation Inhibitors via an Antiviral Immune Response. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017; 106:227-242. [DOI: 10.1016/bs.apcsb.2016.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Human Endogenous Retroviruses-K (HML-2) Expression Is Correlated with Prognosis and Progress of Hepatocellular Carcinoma. BIOMED RESEARCH INTERNATIONAL 2016; 2016:8201642. [PMID: 28070518 PMCID: PMC5192314 DOI: 10.1155/2016/8201642] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 11/07/2016] [Accepted: 11/22/2016] [Indexed: 12/14/2022]
Abstract
Background. The association between human endogenous retroviruses-K (HERV-K) (HML-2) and human disease, including a variety of cancers, has been indicated. However, the function of HERV-K (HML-2) in the progression of hepatocellular carcinoma (HCC) still remains largely unclear. Methods. We detected the expression of HERV-K (HML-2) in 84 HCC tissues and adjacent nontumor tissues by quantitative real-time PCR (qRT-PCR) and analyzed its correlation with the clinical parameters. Result. The HEVR-K level was significantly increased in HCC compared with adjacent normal tissues (P < 0.01) which was proved to be significantly associated with cirrhosis (P < 0.05), tumor differentiation (P < 0.05), and TNM stage (P < 0.05). Moreover, the high expression of HERV-K (HML-2) had a poorer overall survival than patients with lower expression by a Kaplan-Meier survival analysis (P < 0.01). The multivariate Cox regression analysis indicated that the level of HERV-K (HML-2) was an independent prognostic factor for the overall survival rate of HCC patients. Receiver operating characteristic (ROC) curves demonstrated the diagnostic accuracy of HERV-K (HML-2) expression in HCC (AUC = 0.729, 74.7% sensitivity, and 67.8% specificity). Conclusions. Our results suggested that upregulation of HERV-K (HML-2) in HCC patients was significantly related to cancer progression and poor outcome, indicating that HERV-K (HML-2) might be a novel candidate prognostic biomarker for HCC.
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Expression patterns of endogenous avian retrovirus ALVE1 and its response to infection with exogenous avian tumour viruses. Arch Virol 2016; 162:89-101. [PMID: 27686071 DOI: 10.1007/s00705-016-3086-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 09/21/2016] [Indexed: 02/01/2023]
Abstract
Endogenous retroviruses (ERVs) are genomic elements that are present in a wide range of vertebrates and have been implicated in a variety of human diseases, including cancer. However, the characteristic expression patterns of ERVs, particularly in virus-induced tumours, is not fully clear. DNA methylation was analysed by bisulfite pyrosequencing, and gene expression was analysed by RT-qPCR. In this study, we first found that the endogenous avian retrovirus ALVE1 was highly expressed in some chicken tissues (including the heart, bursa, thymus, and spleen) at 2 days of age, but its expression was markedly decreased at 35 days of age. In contrast, the CpG methylation level of ALVE1 was significantly lower in heart and bursa at 2 days than at 35 days of age. Moreover, we found that the expression of ALVE1 was significantly inhibited in chicken embryo fibroblast cells (CEFs) and MSB1 cells infected with avian leukosis virus subgroup J (ALVJ) and reticuloendotheliosis virus (REV) at the early stages of infection. In contrast, the expression of the ALVE1 env gene was significantly induced in CEFs and MSB1 cells infected with Marek's disease virus (MDV). However, the methylation and expression levels of the ALVE1 long terminal repeat (LTR) did not show obvious alterations in response to viral infection. The present study revealed the expression patterns of ALVE1 in a variety of chicken organs and tissues and in chicken cells in response to avian tumour virus infection. These findings may be of significance for understanding the role and function of ERVs that are present in the host genome.
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40
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Hanke K, Hohn O, Bannert N. HERV-K(HML-2), a seemingly silent subtenant - but still waters run deep. APMIS 2016; 124:67-87. [PMID: 26818263 DOI: 10.1111/apm.12475] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/12/2015] [Indexed: 01/26/2023]
Abstract
A large proportion of the human genome consists of endogenous retroviruses, some of which are well preserved, showing transcriptional activity, and expressing retroviral proteins. The HERV-K(HML-2) family represents the most intact members of these elements, with some having open and intact reading frames for viral proteins and the ability to form virus-like particles. Although generally suppressed in most healthy tissues by a variety of epigenetic processes and antiviral mechanisms, there is evidence that some members of this family are (at least partly) still active - particularly in certain stem cells and various tumors. This raises the possibility of their involvement in tumor induction or in developmental processes. In recent years, many new insights into this fascinating field have been attained, and this review focuses on new discoveries about coevolutionary events and intracellular defense mechanisms against HERV-K(HML-2) activity. We also describe what might occur when these mechanisms fail or become modulated by viral proteins or other viruses and discuss the new vistas opened up by the reconstitution of ancestral viral proteins and even complete HML-2 viruses.
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Affiliation(s)
- Kirsten Hanke
- Department HIV and Other Retroviruses, Robert Koch Institute, Berlin, Germany
| | - Oliver Hohn
- Department HIV and Other Retroviruses, Robert Koch Institute, Berlin, Germany
| | - Norbert Bannert
- Department HIV and Other Retroviruses, Robert Koch Institute, Berlin, Germany
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41
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Hohn O, Mostafa S, Norley S, Bannert N. Development of an antigen-capture ELISA for the detection of the p27-CA protein of HERV-K(HML-2). J Virol Methods 2016; 234:186-92. [PMID: 27142113 DOI: 10.1016/j.jviromet.2016.04.016] [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: 12/11/2015] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 10/21/2022]
Abstract
The detection or quantification of retroviruses is often achieved using an antigen-capture ELISA (AC-ELISA) that targets the Gag capsid (CA) protein. We report here the development of an AC-ELISA specific for the p27-CA protein of HERV-K(HML-2). A monoclonal p27-specific antibody is used for capture and a polyclonal anti-p27-CA immune serum generated in rabbits serves for detection. The assay was shown to be specific for HERV-K(HML-2), showing no evidence of cross reactivity with the human retroviruses HIV-1, HIV-2 and HTLV-1 or with XMRV (as a model non-human gammaretrovirus). Using purified recombinant antigen, the limit of detection was shown to be 130pg/ml. The AC-ELISA can be used to quantify HERV-K(HML-2) expression in teratocarcinoma cell lines and to normalize HERV particles generated by transfecting HEK 293T cells with full-length molecular clones. This novel AC-ELISA also proved useful in studies of virus regulation, for example in demonstrating that HERV-K(HML-2) expression is dramatically enhanced by overexpression of Staufen-1, a binding partner of the HERV-K(HML-2) Rec protein. This specific and sensitive HERV-K(HML-2) AC-ELISA will be a useful tool for investigating many aspects of endogenous retroviruses, from basic research to the role they may play in human diseases or as a surrogate marker for particular diseases.
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Affiliation(s)
- Oliver Hohn
- Robert Koch Institute, Division for HIV and Other Retroviruses, Nordufer 20, 13353 Berlin, Germany
| | - Saeed Mostafa
- Robert Koch Institute, Division for HIV and Other Retroviruses, Nordufer 20, 13353 Berlin, Germany
| | - Stephen Norley
- Robert Koch Institute, Division for HIV and Other Retroviruses, Nordufer 20, 13353 Berlin, Germany
| | - Norbert Bannert
- Robert Koch Institute, Division for HIV and Other Retroviruses, Nordufer 20, 13353 Berlin, Germany.
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Chiappinelli KB, Zahnow CA, Ahuja N, Baylin SB. Combining Epigenetic and Immunotherapy to Combat Cancer. Cancer Res 2016; 76:1683-9. [PMID: 26988985 PMCID: PMC4873370 DOI: 10.1158/0008-5472.can-15-2125] [Citation(s) in RCA: 219] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 10/16/2015] [Indexed: 12/14/2022]
Abstract
The most exciting recent advance for achieving durable management of advanced human cancers is immunotherapy, especially the concept of immune checkpoint blockade. However, with the exception of melanoma, most patients do not respond to immunotherapy alone. A growing body of work has shown that epigenetic drugs, specifically DNA methyltransferase inhibitors, can upregulate immune signaling in epithelial cancer cells through demethylation of endogenous retroviruses and cancer testis antigens. These demethylating agents may induce T-cell attraction and enhance immune checkpoint inhibitor efficacy in mouse models. Current clinical trials are testing this combination therapy as a potent new cancer management strategy. Cancer Res; 76(7); 1683-9. ©2016 AACR.
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Affiliation(s)
- Katherine B Chiappinelli
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland
| | - Cynthia A Zahnow
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland
| | - Nita Ahuja
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland
| | - Stephen B Baylin
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland.
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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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44
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Chiappinelli KB, Strissel PL, Desrichard A, Li H, Henke C, Akman B, Hein A, Rote NS, Cope LM, Snyder A, Makarov V, Budhu S, Buhu S, Slamon DJ, Wolchok JD, Pardoll DM, Beckmann MW, Zahnow CA, Merghoub T, Mergoub T, Chan TA, Baylin SB, Strick R. Inhibiting DNA Methylation Causes an Interferon Response in Cancer via dsRNA Including Endogenous Retroviruses. Cell 2015; 162:974-86. [PMID: 26317466 PMCID: PMC4556003 DOI: 10.1016/j.cell.2015.07.011] [Citation(s) in RCA: 1150] [Impact Index Per Article: 127.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 05/04/2015] [Accepted: 06/26/2015] [Indexed: 12/18/2022]
Abstract
We show that DNA methyltransferase inhibitors (DNMTis) upregulate immune signaling in cancer through the viral defense pathway. In ovarian cancer (OC), DNMTis trigger cytosolic sensing of double-stranded RNA (dsRNA) causing a type I interferon response and apoptosis. Knocking down dsRNA sensors TLR3 and MAVS reduces this response 2-fold and blocking interferon beta or its receptor abrogates it. Upregulation of hypermethylated endogenous retrovirus (ERV) genes accompanies the response and ERV overexpression activates the response. Basal levels of ERV and viral defense gene expression significantly correlate in primary OC and the latter signature separates primary samples for multiple tumor types from The Cancer Genome Atlas into low versus high expression groups. In melanoma patients treated with an immune checkpoint therapy, high viral defense signature expression in tumors significantly associates with durable clinical response and DNMTi treatment sensitizes to anti-CTLA4 therapy in a pre-clinical melanoma model.
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Affiliation(s)
- Katherine B Chiappinelli
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD 21287, USA
| | - Pamela L Strissel
- Department of Gynaecology and Obstetrics, Laboratory for Molecular Medicine, University-Clinic Erlangen, 91054 Erlangen, Germany
| | - Alexis Desrichard
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Huili Li
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD 21287, USA
| | - Christine Henke
- Department of Gynaecology and Obstetrics, Laboratory for Molecular Medicine, University-Clinic Erlangen, 91054 Erlangen, Germany
| | - Benjamin Akman
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD 21287, USA
| | - Alexander Hein
- Department of Gynaecology and Obstetrics, Laboratory for Molecular Medicine, University-Clinic Erlangen, 91054 Erlangen, Germany
| | - Neal S Rote
- Department of Reproductive Biology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Leslie M Cope
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD 21287, USA
| | - Alexandra Snyder
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Vladimir Makarov
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | | | - Sadna Buhu
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Dennis J Slamon
- The Jonsson Comprehensive Cancer Center, University of California-Los Angeles, Los Angeles, CA 90095, USA
| | - Jedd D Wolchok
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Drew M Pardoll
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD 21287, USA
| | - Matthias W Beckmann
- Department of Gynaecology and Obstetrics, Laboratory for Molecular Medicine, University-Clinic Erlangen, 91054 Erlangen, Germany
| | - Cynthia A Zahnow
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD 21287, USA
| | | | - Taha Mergoub
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Timothy A Chan
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Stephen B Baylin
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD 21287, USA.
| | - Reiner Strick
- Department of Gynaecology and Obstetrics, Laboratory for Molecular Medicine, University-Clinic Erlangen, 91054 Erlangen, Germany.
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Miousse IR, Chalbot MCG, Lumen A, Ferguson A, Kavouras IG, Koturbash I. Response of transposable elements to environmental stressors. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2015; 765:19-39. [PMID: 26281766 PMCID: PMC4544780 DOI: 10.1016/j.mrrev.2015.05.003] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 05/27/2015] [Accepted: 05/28/2015] [Indexed: 12/21/2022]
Abstract
Transposable elements (TEs) comprise a group of repetitive sequences that bring positive, negative, as well as neutral effects to the host organism. Earlier considered as "junk DNA," TEs are now well-accepted driving forces of evolution and critical regulators of the expression of genetic information. Their activity is regulated by epigenetic mechanisms, including methylation of DNA and histone modifications. The loss of epigenetic control over TEs, exhibited as loss of DNA methylation and decondensation of the chromatin structure, may result in TEs reactivation, initiation of their insertional mutagenesis (retrotransposition) and has been reported in numerous human diseases, including cancer. Accumulating evidence suggests that these alterations are not the simple consequences of the disease, but often may drive the pathogenesis, as they can be detected early during disease development. Knowledge derived from the in vitro, in vivo, and epidemiological studies, clearly demonstrates that exposure to ubiquitous environmental stressors, many of which are carcinogens or suspected carcinogens, are capable of causing alterations in methylation and expression of TEs and initiate retrotransposition events. Evidence summarized in this review suggests that TEs are the sensitive endpoints for detection of effects caused by such environmental stressors, as ionizing radiation (terrestrial, space, and UV-radiation), air pollution (including particulate matter [PM]-derived and gaseous), persistent organic pollutants, and metals. Furthermore, the significance of these effects is characterized by their early appearance, persistence and presence in both, target organs and peripheral blood. Altogether, these findings suggest that TEs may potentially be introduced into safety and risk assessment and serve as biomarkers of exposure to environmental stressors. Furthermore, TEs also show significant potential to become invaluable surrogate biomarkers in clinic and possible targets for therapeutic modalities for disease treatment and prevention.
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Affiliation(s)
- Isabelle R Miousse
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Marie-Cecile G Chalbot
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Annie Lumen
- Division of Biochemical Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA.
| | - Alesia Ferguson
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Ilias G Kavouras
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Igor Koturbash
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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Bergallo M, Galliano I, Montanari P, Gambarino S, Mareschi K, Ferro F, Fagioli F, Tovo PA, Ravanini P. CMV induces HERV-K and HERV-W expression in kidney transplant recipients. J Clin Virol 2015; 68:28-31. [PMID: 26071331 DOI: 10.1016/j.jcv.2015.04.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 04/16/2015] [Accepted: 04/21/2015] [Indexed: 11/29/2022]
Abstract
BACKGROUND Human endogenous retrovirus (HERVs) constitute approximately 8% of the human genome. Induction of HERV transcription is possible under certain circumstances, and may have a possible role in some pathological conditions. OBJECTIVES The aim of this study was to evaluate HERV-K and -W pol gene expression in kidney transplant recipients and to investigate the possible relationship between HERVs gene expression and CMV infection in these patients. STUDY DESIGN Thirty-three samples of kidney transplant patients and twenty healthy blood donors were used to analyze, HERV-K and -W pol gene RNA expression by relative quantitative relative Real-Time PCR. RESULT We demonstrated that HERVs pol gene expression levels were higher in kidney transplant recipients than in healthy subjects. Moreover, HERV-K and -W pol gene expression was significantly higher in the group of kidney transplant recipients with high CMV viral load than in the groups with no or moderate CMV viral load. CONCLUSION Our data suggest that CMV may facilitate in vivo HERV activation.
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Affiliation(s)
- Massimiliano Bergallo
- Department of Public Health and Pediatric Sciences, University of Turin, Medical School, 10136 Turin, Italy; Laboratory of Citoimmunodiagnostics, University Hospital City of Science and Health of Turin, Regina Margherita Children's Hospital, Turin, Italy.
| | - Ilaria Galliano
- Department of Public Health and Pediatric Sciences, University of Turin, Medical School, 10136 Turin, Italy; Laboratory of Citoimmunodiagnostics, University Hospital City of Science and Health of Turin, Regina Margherita Children's Hospital, Turin, Italy.
| | - Paola Montanari
- Department of Public Health and Pediatric Sciences, University of Turin, Medical School, 10136 Turin, Italy; Laboratory of Citoimmunodiagnostics, University Hospital City of Science and Health of Turin, Regina Margherita Children's Hospital, Turin, Italy.
| | - Stefano Gambarino
- Laboratory of Citoimmunodiagnostics, University Hospital City of Science and Health of Turin, Regina Margherita Children's Hospital, Turin, Italy.
| | - Katia Mareschi
- Department of Public Health and Pediatric Sciences, University of Turin, Medical School, 10136 Turin, Italy; Pediatric Onco-Hematology, Stem Cell Transplantation and Cellular Therapy Division, City of Science and Health of Turin, Regina Margherita Children's Hospital, Turin, Italy.
| | - Francesca Ferro
- Laboratory of Citoimmunodiagnostics, University Hospital City of Science and Health of Turin, Regina Margherita Children's Hospital, Turin, Italy.
| | - Franca Fagioli
- Pediatric Onco-Hematology, Stem Cell Transplantation and Cellular Therapy Division, City of Science and Health of Turin, Regina Margherita Children's Hospital, Turin, Italy.
| | - Pier-Angelo Tovo
- Department of Public Health and Pediatric Sciences, University of Turin, Medical School, 10136 Turin, Italy; Laboratory of Citoimmunodiagnostics, University Hospital City of Science and Health of Turin, Regina Margherita Children's Hospital, Turin, Italy.
| | - Paolo Ravanini
- Laboratory of Molecular Virology, Azienda Ospedaliero-Universitaria Maggiore della Carità, Novara, Italy.
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Vincendeau M, Göttesdorfer I, Schreml JMH, Wetie AGN, Mayer J, Greenwood AD, Helfer M, Kramer S, Seifarth W, Hadian K, Brack-Werner R, Leib-Mösch C. Modulation of human endogenous retrovirus (HERV) transcription during persistent and de novo HIV-1 infection. Retrovirology 2015; 12:27. [PMID: 25886562 PMCID: PMC4375885 DOI: 10.1186/s12977-015-0156-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 03/05/2015] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The human genome contains multiple LTR elements including human endogenous retroviruses (HERVs) that together account for approximately 8-9% of the genomic DNA. At least 40 different HERV groups have been assigned to three major HERV classes on the basis of their homologies to exogenous retroviruses. Although most HERVs are silenced by a variety of genetic and epigenetic mechanisms, they may be reactivated by environmental stimuli such as exogenous viruses and thus may contribute to pathogenic conditions. The objective of this study was to perform an in-depth analysis of the influence of HIV-1 infection on HERV activity in different cell types. RESULTS A retrovirus-specific microarray that covers major HERV groups from all three classes was used to analyze HERV transcription patterns in three persistently HIV-1 infected cell lines of different cellular origins and in their uninfected counterparts. All three persistently infected cell lines showed increased transcription of multiple class I and II HERV groups. Up-regulated transcription of five HERV taxa (HERV-E, HERV-T, HERV-K (HML-10) and two ERV9 subgroups) was confirmed by quantitative reverse transcriptase PCR analysis and could be reversed by knock-down of HIV-1 expression with HIV-1-specific siRNAs. Cells infected de novo by HIV-1 showed stronger transcriptional up-regulation of the HERV-K (HML-2) group than persistently infected cells of the same origin. Analysis of transcripts from individual members of this group revealed up-regulation of predominantly two proviral loci (ERVK-7 and ERVK-15) on chromosomes 1q22 and 7q34 in persistently infected KE37.1 cells, as well as in de novo HIV-1 infected LC5 cells, while only one single HML-2 locus (ERV-K6) on chromosome 7p22.1 was activated in persistently infected LC5 cells. CONCLUSIONS Our results demonstrate that HIV-1 can alter HERV transcription patterns of infected cells and indicate a correlation between activation of HERV elements and the level of HIV-1 production. Moreover, our results suggest that the effects of HIV-1 on HERV activity may be far more extensive and complex than anticipated from initial studies with clinical material.
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Affiliation(s)
- 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.
| | - Ingmar Göttesdorfer
- Institute of Virology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.
| | - Julia M H Schreml
- Department of Hematology and Oncology, University Hospital Mannheim, University of Heidelberg, Mannheim, Germany.
| | - Armand G Ngounou Wetie
- Institute of Virology, 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.
| | - Alex D Greenwood
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany.
| | - Markus Helfer
- Institute of Virology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.
| | - Susanne Kramer
- Institute of Virology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.
| | - Wolfgang Seifarth
- Department of Hematology and Oncology, University Hospital Mannheim, University of Heidelberg, Mannheim, Germany.
| | - Kamyar Hadian
- Research Unit Cellular Signal Integration, Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany. .,Assay Development and Screening Platform, Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.
| | - Ruth Brack-Werner
- Institute of Virology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.
| | - Christine Leib-Mösch
- Institute of Virology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany. .,Department of Hematology and Oncology, University Hospital Mannheim, University of Heidelberg, Mannheim, Germany.
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48
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Emmer A, Staege MS, Kornhuber ME. The retrovirus/superantigen hypothesis of multiple sclerosis. Cell Mol Neurobiol 2014; 34:1087-96. [PMID: 25138639 DOI: 10.1007/s10571-014-0100-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 08/09/2014] [Indexed: 12/21/2022]
Abstract
The pathogenesis of multiple sclerosis (MS) is as yet unknown. Commonly, MS is assumed to be due to an autoimmune inflammation of the central nervous system (CNS). Neurodegeneration is regarded to be a secondary reaction. This concept is increasingly being challenged. Human endogenous retroviruses (HERV) that could be locally activated in the CNS have been proposed as an alternative concept. HERV-encoded envelope proteins (env) can act as strong immune stimulators (superantigens). Thus, slow disease progression following neurodegeneration might be induced by re-activation of HERV expression directly, while relapses in parallel to inflammation might be secondary to the expression of HERV-encoded superantigens. It has been shown previously that T-cell superantigens are capable to induce a cellular inflammatory reaction in the CNS of experimental animals similar to that in MS. Furthermore, B-cell superantigens have been shown to activate blood leucocytes in vitro to produce immunoglobulin in an oligoclonal manner. It remains to be established, whether the outlined hypothesis accords with all known features of MS. Furthermore, anti-HERV agents may be taken into consideration to enrich and improve MS therapy.
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Affiliation(s)
- Alexander Emmer
- Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany,
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49
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Downey RF, Sullivan FJ, Wang-Johanning F, Ambs S, Giles FJ, Glynn SA. Human endogenous retrovirus K and cancer: Innocent bystander or tumorigenic accomplice? Int J Cancer 2014; 137:1249-57. [PMID: 24890612 PMCID: PMC6264888 DOI: 10.1002/ijc.29003] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 05/02/2014] [Accepted: 05/09/2014] [Indexed: 12/20/2022]
Abstract
Harbored as relics of ancient germline infections, human endogenous retroviruses (HERVs) now constitute up to 8% of our genome. A proportion of this sequence has been co-opted for molecular and cellular processes, beneficial to human physiology, such as the fusogenic activity of the envelope protein, a vital component of placentogenesis. However, the discovery of high levels of HERV-K mRNA and protein and even virions in a wide array of cancers has revealed that HERV-K may be playing a more sinister role–a role as an etiological agent in cancer itself. Whether the presence of this retroviral material is simply an epiphenomenon, or an actual causative factor, is a hotly debated topic. This review will summarize the current state of knowledge regarding HERV-K and cancer and attempt to outline the potential mechanisms by which HERV-K could be involved in the onset and promotion of carcinogenesis.
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Affiliation(s)
- Ronan F Downey
- Prostate Cancer Institute, National University of Ireland Galway, Galway, Ireland
| | - Francis J Sullivan
- Prostate Cancer Institute, National University of Ireland Galway, Galway, Ireland.,Department of Radiation Oncology, Galway University Hospitals, Galway, Ireland
| | | | - Stefan Ambs
- Laboratory of Human Carcinogenesis, National Cancer Institute, Bethesda, MD
| | - Francis J Giles
- Prostate Cancer Institute, National University of Ireland Galway, Galway, Ireland.,HRB Clinical Research Facilities Galway & Dublin, National University of Ireland Galway and Trinity College Dublin, Galway, Ireland
| | - Sharon A Glynn
- Prostate Cancer Institute, National University of Ireland Galway, Galway, Ireland
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50
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Douville RN, Nath A. Human endogenous retroviruses and the nervous system. HANDBOOK OF CLINICAL NEUROLOGY 2014; 123:465-85. [PMID: 25015500 DOI: 10.1016/b978-0-444-53488-0.00022-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Renée N Douville
- Department of Microbiology, University of Winnipeg, Winnipeg, Manitoba, Canada
| | - Avindra Nath
- Section of Infections of the Nervous System, National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, MD, USA.
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