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Dai L, Fan J, Qin Z. Development of human endogenous retrovirus type K- related treatments for human diseases. J Med Virol 2024; 96:e29532. [PMID: 38497450 DOI: 10.1002/jmv.29532] [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: 02/12/2024] [Revised: 03/03/2024] [Accepted: 03/06/2024] [Indexed: 03/19/2024]
Abstract
Human endogenous retroviruses (HERVs) constitute approximately 8% of the human genome and have long been regarded as silent passengers within our genomes. However, the reactivation of HERVs has been increasingly linked to a range of human diseases, particularly the HERV-K (HML-2) family. Many studies are dedicated to elucidating the potential role of HERV-K in pathogenicity. While the underlying mechanisms require further investigation, targeting HERV-K transactivation emerges as a promising avenue for treating human diseases, including cancer, autoimmune disorders, neurodegenerative conditions, and infectious diseases. In this review, we summarize recent advancements in the development of HERV-K-targeted therapeutic strategies against various human diseases, including antiretroviral drugs, immunotherapy, and vaccines.
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Affiliation(s)
- Lu Dai
- Department of Pathology, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Jiaojiao Fan
- Department of Pathology, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Zhiqiang Qin
- Department of Pathology, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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2
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Cherkasova EA, Chen L, Childs RW. Mechanistic regulation of HERV activation in tumors and implications for translational research in oncology. Front Cell Infect Microbiol 2024; 14:1358470. [PMID: 38379771 PMCID: PMC10877039 DOI: 10.3389/fcimb.2024.1358470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 01/22/2024] [Indexed: 02/22/2024] Open
Abstract
Transcription of distinct loci of human endogenous retroviruses (HERVs) and in some cases, translation of these transcripts have been consistently observed in many types of cancer. It is still debated whether HERV activation serves as a trigger for carcinogenesis or rather occurs as a consequence of epigenetic alterations and other molecular sequelae that characterize cellular transformation. Here we review the known molecular and epigenetic mechanisms of HERV activation in cancer cells as well as its potential contribution to carcinogenesis. Further, we describe the use of HERV expression in cancer diagnostic and characterize the potential of HERV-derived antigens to serve as novel targets for cancer immunotherapy. We believe this review, which summarizes both what is known as well as unknown in this rapidly developing field, will boost interest in research on the therapeutic potential of targeting HERV elements in tumors and the impact of HERV activation in oncogenesis.
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Affiliation(s)
| | | | - Richard W. Childs
- Laboratory of Transplantation Immunotherapy, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States
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3
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Shin W, Mun S, Han K. Human Endogenous Retrovirus-K (HML-2)-Related Genetic Variation: Human Genome Diversity and Disease. Genes (Basel) 2023; 14:2150. [PMID: 38136972 PMCID: PMC10742618 DOI: 10.3390/genes14122150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/23/2023] [Accepted: 11/26/2023] [Indexed: 12/24/2023] Open
Abstract
Human endogenous retroviruses (HERVs) comprise a significant portion of the human genome, making up roughly 8%, a notable comparison to the 2-3% represented by coding sequences. Numerous studies have underscored the critical role and importance of HERVs, highlighting their diverse and extensive influence on the evolution of the human genome and establishing their complex correlation with various diseases. Among HERVs, the HERV-K (HML-2) subfamily has recently attracted significant attention, integrating into the human genome after the divergence between humans and chimpanzees. Its insertion in the human genome has received considerable attention due to its structural and functional characteristics and the time of insertion. Originating from ancient exogenous retroviruses, these elements succeeded in infecting germ cells, enabling vertical transmission and existing as proviruses within the genome. Remarkably, these sequences have retained the capacity to form complete viral sequences, exhibiting activity in transcription and translation. The HERV-K (HML-2) subfamily is the subject of active debate about its potential positive or negative effects on human genome evolution and various pathologies. This review summarizes the variation, regulation, and diseases in human genome evolution arising from the influence of HERV-K (HML-2).
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Affiliation(s)
- Wonseok Shin
- NGS Clinical Laboratory, Division of Cancer Research, Dankook University Hospital, Cheonan 31116, Republic of Korea;
- Smart Animal Bio Institute, Dankook University, Cheonan 31116, Republic of Korea;
| | - Seyoung Mun
- Smart Animal Bio Institute, Dankook University, Cheonan 31116, Republic of Korea;
- College of Science & Technology, Dankook University, Cheonan 31116, Republic of Korea
- Center for Bio-Medical Engineering Core Facility, Dankook University, Cheonan 31116, Republic of Korea
| | - Kyudong Han
- Smart Animal Bio Institute, Dankook University, Cheonan 31116, Republic of Korea;
- Center for Bio-Medical Engineering Core Facility, Dankook University, Cheonan 31116, Republic of Korea
- Department of Microbiology, College of Science & Technology, Dankook University, Cheonan 31116, Republic of Korea
- Department of Bioconvergence Engineering, Dankook University, Yongin 16890, Republic of Korea
- R&D Center, HuNBiome Co., Ltd., Seoul 08507, Republic of Korea
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Abstract
Our defenses against infection rely on the ability of the immune system to distinguish invading pathogens from self. This task is exceptionally challenging, if not seemingly impossible, in the case of retroviruses that have integrated almost seamlessly into the host. This review examines the limits of innate and adaptive immune responses elicited by endogenous retroviruses and other retroelements, the targets of immune recognition, and the consequences for host health and disease. Contrary to theoretical expectation, endogenous retroelements retain substantial immunogenicity, which manifests most profoundly when their epigenetic repression is compromised, contributing to autoinflammatory and autoimmune disease and age-related inflammation. Nevertheless, recent evidence suggests that regulated immune reactivity to endogenous retroelements is integral to immune system development and function, underpinning cancer immunosurveillance, resistance to infection, and responses to the microbiota. Elucidation of the interaction points with endogenous retroelements will therefore deepen our understanding of immune system function and contribution to disease.
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Affiliation(s)
- George Kassiotis
- Retroviral Immunology Laboratory, The Francis Crick Institute, London, United Kingdom;
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
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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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Kitsou K, Lagiou P, Magiorkinis G. Human endogenous retroviruses in cancer: Oncogenesis mechanisms and clinical implications. J Med Virol 2023; 95:e28350. [PMID: 36428242 PMCID: PMC10108094 DOI: 10.1002/jmv.28350] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 11/22/2022] [Accepted: 11/23/2022] [Indexed: 11/28/2022]
Abstract
Human Endogenous Retroviruses (HERVs) are viral sequences integrated into the human genome, resulting from the infection of human germ-line cells by ancient exogenous retroviruses. Despite losing their replication and retrotransposition abilities, HERVs appear to have been co-opted in human physiological functions while their aberrant expression is linked to human disease. The role of HERVs in multiple malignancies has been demonstrated, however, the extent to which HERV activation and expression participate in the development of cancer is not yet fully comprehended. In this review article, we discuss the presumed role of HERVs in carcinogenesis and their promising diagnostic and prognostic implications. Additionally, we explore recent data on the HERVs in cancer therapeutics, either through the manipulation of their expression, to induce antitumor innate immunity responses or as cancer immunotherapy targets. Finally, more precise and higher resolution high-throughput sequencing approaches will further elucidate HERV participation in human physiological and pathological processes.
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Affiliation(s)
- Konstantina Kitsou
- Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National and Kapodistrian, University of Athens, Goudi, Greece
| | - Pagona Lagiou
- Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National and Kapodistrian, University of Athens, Goudi, Greece
| | - Gkikas Magiorkinis
- Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National and Kapodistrian, University of Athens, Goudi, Greece
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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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Müller MD, Holst PJ, Nielsen KN. A Systematic Review of Expression and Immunogenicity of Human Endogenous Retroviral Proteins in Cancer and Discussion of Therapeutic Approaches. Int J Mol Sci 2022; 23:ijms23031330. [PMID: 35163254 PMCID: PMC8836156 DOI: 10.3390/ijms23031330] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 02/06/2023] Open
Abstract
Human endogenous retroviruses (HERVs) are remnants of ancient retroviral infections that have become fixed in the human genome. While HERV genes are typically silenced in healthy somatic cells, there are numerous reports of HERV transcription and translation across a wide spectrum of cancers, while T and B cell responses against HERV proteins have been detected in cancer patients. This review systematically categorizes the published evidence on the expression of and adaptive immune response against specific HERVs in distinct cancer types. A systematic literature search was performed using Medical Search Headings (MeSH) in the PubMed/Medline database. Papers were included if they described the translational activity of HERVs. We present multiple tables that pair the protein expression of specific HERVs and cancer types with information on the quality of the evidence. We find that HERV-K is the most investigated HERV. HERV-W (syncytin-1) is the second-most investigated, while other HERVs have received less attention. From a therapeutic perspective, HERV-K and HERV-E are the only HERVs with experimental demonstration of effective targeted therapies, but unspecific approaches using antiviral and demethylating agents in combination with chemo- and immunotherapies have also been investigated.
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Affiliation(s)
- Mikkel Dons Müller
- Institute of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark;
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Endogenous Retroviral Elements in Human Development and Central Nervous System Embryonal Tumors. J Pers Med 2021; 11:jpm11121332. [PMID: 34945804 PMCID: PMC8708524 DOI: 10.3390/jpm11121332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 01/21/2023] Open
Abstract
Human endogenous retroviruses (HERVs), which are critical to normal embryologic development and downregulated during normal maturation, have been implicated in a variety of cancers. Abnormal persistent production of HERVs has been suggested to play a role in oncogenesis and to confer stem cell properties to cells. We recently demonstrated that the most recently incorporated HERV element (HERV-K HML-2) has been associated with the pathogenesis of the embryonal atypical teratoid rhabdoid tumor (AT/RT), shifting our understanding of embryonal tumor development. HML-2 expression is vital for proper human development and its expression is suppressed via methylation or chromatin remodeling as cells differentiate. We previously found that dysfunctional chromatin remodeling due to loss of SMARCB1 expression induces HML-2 envelope (env) expression, impairing cellular differentiation and migration, and facilitating tumor growth in AT/RT. Epigenetic dysregulation in other embryonal tumors with concomitant expression of stem-cell markers may facilitate HML-2 expression. Future studies could utilize HML-2 as potential diagnostic criteria, use its expression as a treatment biomarker, and investigate the efficacy of therapies targeting cells with high HML-2 expression.
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Mihelson N, McGavern DB. Viral Control of Glioblastoma. Viruses 2021; 13:v13071264. [PMID: 34209584 PMCID: PMC8310222 DOI: 10.3390/v13071264] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 12/11/2022] Open
Abstract
Glioblastoma multiforme (GBM) is a universally lethal cancer of the central nervous system. Patients with GBM have a median survival of 14 months and a 5-year survival of less than 5%, a grim statistic that has remained unchanged over the last 50 years. GBM is intransigent for a variety of reasons. The immune system has a difficult time mounting a response against glioblastomas because they reside in the brain (an immunologically dampened compartment) and generate few neoantigens relative to other cancers. Glioblastomas inhabit the brain like sand in the grass and display a high degree of intra- and inter-tumoral heterogeneity, impeding efforts to therapeutically target a single pathway. Of all potential therapeutic strategies to date, virotherapy offers the greatest chance of counteracting each of the obstacles mounted by GBM. Virotherapy can xenogenize a tumor that is deft at behaving like “self”, triggering adaptive immune recognition in an otherwise immunologically quiet compartment. Viruses can also directly lyse tumor cells, creating damage and further stimulating secondary immune reactions that are detrimental to tumor growth. In this review, we summarize the basic immune mechanisms underpinning GBM immune evasion and the recent successes achieved using virotherapies.
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HERV-K Gag RNA and Protein Levels Are Elevated in Malignant Regions of the Prostate in Males with Prostate Cancer. Viruses 2021; 13:v13030449. [PMID: 33802118 PMCID: PMC7999808 DOI: 10.3390/v13030449] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/04/2021] [Accepted: 03/08/2021] [Indexed: 12/14/2022] Open
Abstract
Heightened expression of human endogenous retrovirus (HERV) sequences has been associated with a range of malignancies, including prostate cancer, suggesting that they may serve as useful diagnostic or prognostic cancer biomarkers. We analysed the expression of HERV-K (Gag and Env/Np9 regions), HERV-E 4.1 (Pol and Env regions), HERV-H (Pol) and HERV-W (Gag) sequences in prostate cancer cells lines and normal prostate epithelial cells using qRT-PCR. HERV expression was also analysed in matched malignant and benign prostate tissue samples from men with prostate cancer (n = 27, median age 65.2 years (range 47-70)) and compared to prostate cancer-free male controls (n = 11). Prostate cancer epithelial cell lines exhibited a signature of HERV RNA overexpression, with all HERVs analysed, except HERV-E Pol, showing heightened expression in at least two, but more commonly all, cell lines analysed. Analysis of primary prostate material indicated increased expression of HERV-E Pol but decreased expression of HERV-E Env in both malignant and benign regions of the prostate in men with prostate cancer as compared to those without. Expression of HERV-K Gag was significantly higher in malignant regions of the prostate in men with prostate cancer as compared to matched benign regions and prostate cancer-free men (p < 0.001 for both), with 85.2% of prostate cancers donors showing malignancy-associated upregulation of HERV-K Gag RNA. HERV-K Gag protein was detected in 12/18 (66.7%) malignant tissues using immunohistochemistry, but only 1/18 (5.6%) benign tissue sections. Heightened expression of HERV-K Gag RNA and protein appears to be a sensitive and specific biomarker of prostate malignancy in this cohort of men with prostate carcinoma, supporting its potential utility as a non-invasive, adjunct clinical biomarker.
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Grabski DF, Ratan A, Gray LR, Bekiranov S, Rekosh D, Hammarskjold ML, Rasmussen SK. Upregulation of human endogenous retrovirus-K (HML-2) mRNAs in hepatoblastoma: Identification of potential new immunotherapeutic targets and biomarkers. J Pediatr Surg 2021; 56:286-292. [PMID: 32682541 DOI: 10.1016/j.jpedsurg.2020.05.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/28/2020] [Accepted: 05/18/2020] [Indexed: 12/28/2022]
Abstract
PURPOSE Hepatoblastoma is the most common liver malignancy in children. In order to advance therapy against hepatoblastoma, novel immunologic targets and biomarkers are needed. Our purpose in this investigation is to examine hepatoblastoma transcriptomes for the expression of a class of genomic elements known as Human Endogenous Retrovirus (HERVs). HERVs are abundant in the human genome and are biologically active elements that have been associated with multiple malignancies and proposed as immunologic targets in a subset of tumors. A sub-family of HERVs, HERV-K(HML-2) (HERV-K), have been shown to be tightly regulated in fetal development, making investigation of these elements in pediatric tumors paramount. METHODS We first created a HERVK-FASTA file utilizing 91 previously described HML-2 proviruses. We then concatenated the file onto the GRCh38.95 cDNA library from Ensembl. We used this reference database to evaluate existing RNA-seq data from 10 hepatoblastoma tumors and 3 normal liver controls (GEO accession ID: GSE8977575). Quantification and differential proviral expression analysis between hepatoblastoma and normal liver controls was performed using the pseudo-alignment program Salmon and DESeq2, respectively. RESULTS HERV-K mRNA was expressed in hepatoblastoma from multiple proviral loci. All expressed HERV-K proviral loci were upregulated in hepatoblastoma compared to normal liver controls. Five HERV-K proviruses (1q21.3, 3q27.2, 7q22.2, 12q24.33 and 17p13.1) were significantly differentially expressed (p-adjusted value <0.05, |log2 fold change| > 1.5) across conditions. The provirus at 17p13.1 had an approximately 300-fold increased expression in hepatoblastoma as compared to normal liver. This was in part due to the near absence of HERV-K mRNA at the 17p13.1 locus in fully differentiated liver samples. CONCLUSIONS Our investigation demonstrates that HERV-K is expressed from multiple loci in hepatoblastoma and that the expression is increased for several proviruses compared to normal liver controls. Our results suggest that HERV-K mRNA expression may be useful as a biomarker in hepatoblastoma, given the large differential expression profiles in hepatoblastoma, with very low mRNA levels in liver control samples.
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Affiliation(s)
- David F Grabski
- Department of Surgery, University of Virginia School of Medicine, Charlottesville, Virginia; Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia
| | - Aakrosh Ratan
- Center for Public Health Genomics, Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Laurie R Gray
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia; Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Stefan Bekiranov
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia
| | - David Rekosh
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia; Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Marie-Louise Hammarskjold
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia; Department of Microbiology, Immunology and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Sara K Rasmussen
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia; Seattle Children's Hospital, Division of Transplantation, University of Washington Department of Surgery, 4800 Sand Point Way, Seattle, WA 98105.
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Liu CH, Grandi N, Palanivelu L, Tramontano E, Lin LT. Contribution of Human Retroviruses to Disease Development-A Focus on the HIV- and HERV-Cancer Relationships and Treatment Strategies. Viruses 2020; 12:E852. [PMID: 32759845 PMCID: PMC7472297 DOI: 10.3390/v12080852] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/28/2020] [Accepted: 07/31/2020] [Indexed: 02/06/2023] Open
Abstract
Animal retroviruses are known for their transforming potential, and this is also true for the ones hosted by humans, which have gathered expanding attention as one of the potent causative agents in various disease, including specific cancer types. For instance, Human T Lymphotropic virus (HTLV) is a well-studied class of oncoviruses causing T cell leukemia, while human immunodeficiency virus (HIV) leads to acquired immunodeficiency syndrome (AIDS), which is linked to a series of defining cancers including Kaposi sarcoma, certain types of non-Hodgkin lymphoma, and cervical cancer. Of note, in addition to these "modern" exogenous retroviruses, our genome harbors a staggering number of human endogenous retroviruses (HERVs). HERVs are the genetic remnants of ancient retroviral germline infection of human ancestors and are typically silenced in normal tissues due to inactivating mutations and sequence loss. While some HERV elements have been appropriated and contribute to human physiological functions, others can be reactivated through epigenetic dysregulations to express retroviral elements and promote carcinogenesis. Conversely, HERV replication intermediates or protein products can also serve as intrinsic pathogen-associated molecular patterns that cause the immune system to interpret it as an exogenous infection, thereby stimulating immune responses against tumors. As such, HERVs have also been targeted as a potential internal strategy to sensitize tumor cells for promising immunotherapies. In this review, we discuss the dynamic role of human retroviruses in cancer development, focusing on HIV and HERVs contribution. We also describe potential treatment strategies, including immunotherapeutic targeting of HERVs, inhibiting DNA methylation to expose HERV signatures, and the use of antiretroviral drugs against HIV and HERVs, which can be employed as prospective anti-cancer modalities.
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Affiliation(s)
- Ching-Hsuan Liu
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan;
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Nicole Grandi
- Department of Life and Environmental Sciences, University of Cagliari, Monserrato, 09042 Cagliari, Italy; (N.G.); (E.T.)
| | - Lalitha Palanivelu
- International Master Program in Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan;
| | - Enzo Tramontano
- Department of Life and Environmental Sciences, University of Cagliari, Monserrato, 09042 Cagliari, Italy; (N.G.); (E.T.)
| | - Liang-Tzung Lin
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan;
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
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14
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Xue B, Sechi LA, Kelvin DJ. Human Endogenous Retrovirus K (HML-2) in Health and Disease. Front Microbiol 2020; 11:1690. [PMID: 32765477 PMCID: PMC7380069 DOI: 10.3389/fmicb.2020.01690] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 06/29/2020] [Indexed: 02/05/2023] Open
Abstract
Human endogenous retroviruses (HERVs) are derived from exogenous retrovirus infections in the evolution of primates and account for about 8% of the human genome. They were considered as silent passengers within our genomes for a long time, however, reactivation of HERVs has been associated with tumors and autoimmune diseases, especially the HERV-K (HML-2) family, the most recent integration groups with the least number of mutations and the most biologically active to encode functional retroviral proteins and produce retrovirus-like particles. Increasing studies are committed to determining the potential role of HERV-K (HML-2) in pathogenicity. Although there is still no evidence for HERV-K (HML-2) as a direct cause of diseases, aberrant expression profiles of the HERV-K (HML-2) transcripts and their regulatory function to their proximal host-genes were identified in different diseases. In this review, we summarized the advances between HERV-K (HML-2) and diseases to provide basis for further studies on the causal relationship between HERV-K (HML-2) and diseases. We recommended more attention to polymorphic integrated HERV-K (HML-2) loci which could be genetic causative factors and be associated with inter-individual differences in tumorigenesis and autoimmune diseases.
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Affiliation(s)
- Bei Xue
- Division of Immunology, Shantou University Medical College, Shantou, China
- Department of Microbiology and Immunology, Canadian Center for Vaccinology, Dalhousie University, Halifax, NS, Canada
| | - Leonardo A. Sechi
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
- Mediterranean Center for Disease Control, University of Sassari, Sassari, Italy
| | - David J. Kelvin
- Division of Immunology, Shantou University Medical College, Shantou, China
- Department of Microbiology and Immunology, Canadian Center for Vaccinology, Dalhousie University, Halifax, NS, Canada
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
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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: 39] [Impact Index Per Article: 9.8] [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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Ye X, Waite JC, Dhanik A, Gupta N, Zhong M, Adler C, Malahias E, Ni M, Wei Y, Gurer C, Zhang W, Macdonald LE, Murphy AJ, Sleeman MA, Skokos D. Endogenous retroviral proteins provide an immunodominant but not requisite antigen in a murine immunotherapy tumor model. Oncoimmunology 2020; 9:1758602. [PMID: 32923116 PMCID: PMC7458611 DOI: 10.1080/2162402x.2020.1758602] [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] [Indexed: 12/15/2022] Open
Abstract
Clinical observations suggest that responses to cancer immunotherapy are correlated with intra-tumoral T cell receptor (TCR) clonality, tumor mutation burden (TMB) and host HLA genotype, highlighting the importance of host T cell recognition of tumor antigens. However, the dynamic interplay between T cell activation state and changes in TCR repertoire in driving the identification of potential immunodominant antigen(s) remains largely unexplored. Here, we performed single-cell RNA-sequencing on CD8+ tumor-infiltrating T cells (TILs) using the murine colorectal tumor model MC38 to identify unique TCR sequences and validate their tumor reactivity. We found that the majority of clonally expanded TILs are tumor-reactive and their TCR repertoire is unique amongst individual MC38 tumor-bearing mice. Our query identified that multiple expanded TCR clones recognized the retroviral epitope p15E as an immunodominant antigen. In addition, we found that the endogenous retroviral genome encoding for p15E is highly expressed in MC38 tumors, but not in normal tissues, due to epigenetic derepression. Further, we demonstrated that the p15E-specific TILs exhibit an activated phenotype and an increase in frequency upon treatment with anti-41BB and anti-PD-1 combination immunotherapy. Importantly, we showed that although p15E-specific TILs are not required to mount a primary anti-tumor response, they contributed to the development of strong immune memory. Overall our results revealed that endogenous retroviral antigens expressed by tumor cells may represent an important and underappreciated category of tumor antigens that could be readily targeted in the clinic.
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Affiliation(s)
- Xuan Ye
- Cancer Immunology, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Janelle C Waite
- Cancer Immunology, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Ankur Dhanik
- Cancer Immunology, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Namita Gupta
- Cancer Immunology, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Maggie Zhong
- Cancer Immunology, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Christina Adler
- Cancer Immunology, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | | | - Min Ni
- Cancer Immunology, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Yi Wei
- Cancer Immunology, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Cagan Gurer
- Cancer Immunology, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Wen Zhang
- Cancer Immunology, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Lynn E Macdonald
- Cancer Immunology, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Andrew J Murphy
- Cancer Immunology, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | | | - Dimitris Skokos
- Cancer Immunology, Regeneron Pharmaceuticals, Tarrytown, NY, USA
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Wang M, Qiu Y, Liu H, Liang B, Fan B, Zhou X, Liu D. Transcription profile of human endogenous retroviruses in response to dengue virus serotype 2 infection. Virology 2020; 544:21-30. [PMID: 32174511 DOI: 10.1016/j.virol.2020.01.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 01/14/2020] [Accepted: 01/27/2020] [Indexed: 12/12/2022]
Abstract
Human endogenous retroviruses (HERVs), the remains of retroviruses infection in our ancestors' germline cell over millions of years, take up about 8% of the human genome in total. HERV transcription has been detected in various cancers and diseases. However, the interaction between HERV expression and viral infection has not been fully elucidated. Here, we provided the first transcriptional profile of HERVs in dengue virus serotype 2 (DENV-2) infected A549 cells by using high-throughput RNA sequencing. The results showed that a number of HERVs and human genes were significantly differentially expressed in response to DENV-2 infection. Further bioinformatic analyses indicated a correlation between HERVs and human genes. In particular, the genes near the HERVs activated by dengue infection were dominantly enriched in the antiviral immune response. Taken together, our findings suggest that activated HERVs may be involved in the cellular immune response to viral infection by coexpressing with nearby host genes.
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Affiliation(s)
- Miao Wang
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, 430071, China; Computational Virology Group, Center for Bacteria and Viruses Resources and Bioinformation, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yang Qiu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Haizhou Liu
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, 430071, China; Computational Virology Group, Center for Bacteria and Viruses Resources and Bioinformation, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bilin Liang
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, 430071, China; Computational Virology Group, Center for Bacteria and Viruses Resources and Bioinformation, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Baofeng Fan
- Airforce Medical Center, PLA, Beijing, 100142, China
| | - Xi Zhou
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Di Liu
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, 430071, China; Computational Virology Group, Center for Bacteria and Viruses Resources and Bioinformation, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China; University of Chinese Academy of Sciences, Beijing, 100049, China; First Affiliated Hospital of Xinjiang Medical University, Urumqi, 830054, China.
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Close to the Bedside: A Systematic Review of Endogenous Retroviruses and Their Impact in Oncology. J Surg Res 2019; 240:145-155. [PMID: 30933828 DOI: 10.1016/j.jss.2019.02.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 12/22/2018] [Accepted: 02/04/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND Human endogenous retroviruses (HERVs) are genetic elements in the human genome, which resulted from ancient retroviral germline infections. HERVs have strong transcriptional promoters and enhancers that affect a cell's transcriptome. They also encode proteins that can exert effects in human cells. This review examines how our increased understanding of HERVs have led to their potential use as biomarkers and immunologic targets. MATERIAL AND METHODS PubMed/Medline, Embase, Web of Science, and Cochrane databases were used in a systematic search to identify all articles studying the potential impact of HERVs on surgical diseases. The search included studies that involved clinical patient samples in diseases including cancer, inflammatory conditions, and autoimmune disease. Articles focused on conditions not routinely managed by surgeons were excluded. RESULTS Eighty six articles met inclusion and quality criteria for this review and were included. Breast cancer and melanoma have robust evidence regarding the use of HERVs as potential tumor markers and immunologic targets. Reported evidence of the activity of HERVs in colorectal cancer, pancreatic cancer, hepatocellular cancer, prostate and ovarian cancer, germ cell tumors as well as idiopathic pulmonary hypertension, and the inflammatory response in burns was also reviewed. CONCLUSIONS Increasingly convincing evidence indicates that HERVs may play a role in solid organ malignancy and present important biomarkers or immunologic targets in multiple cancers. Innovative investigation of HERVs is a valuable focus of translational research and can deepen our understanding of cellular physiology and the effects of endogenous retroviruses on human biology. As strategies for treatment continue to focus on genome-based interventions, understanding the impact of endogenous retroviruses on human disease will be critical.
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19
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Chen J, Foroozesh M, Qin Z. Transactivation of human endogenous retroviruses by tumor viruses and their functions in virus-associated malignancies. Oncogenesis 2019; 8:6. [PMID: 30643113 PMCID: PMC6331641 DOI: 10.1038/s41389-018-0114-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 10/24/2018] [Accepted: 11/26/2018] [Indexed: 02/07/2023] Open
Abstract
Human endogenous retroviruses (HERVs), viral-associated sequences, are normal components of the human genome and account for 8–9% of our genome. These original provirus sequences can be transactivated to produce functional products. Several reactivated HERVs have been implicated in cancers and autoimmune diseases. An emerging body of literature supports a potential role of reactivated HERVs in viral diseases, in particular viral-associated neoplasms. Demystifying studies on the mechanism(s) of HERV reactivation could provide a new framework for the development of treatment and prevention strategies targeting virus-associated tumors. Although available data suggest that co-infection by other viruses, such as Kaposi’s Sarcoma-associated herpesvirus (KSHV) and Epstein–Barr virus (EBV), may be a crucial driving force to transactivate HERV boom, the mechanisms of action of viral infection-induced HERV transactivation and the contributions of HERVs to viral oncogenesis warrant further studies. Here, we review viral co-infection contributes to HERVs transactivation with focus on human viral infection associated oncogenesis and diseases, including the abilities of viral regulators involved in HERV reactivation, and physiological effects of viral infection response on HERV reactivation.
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Affiliation(s)
- Jungang Chen
- Department of Pathology, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, 4301 W Markham St, Little Rock, AR, 72205, USA
| | - Maryam Foroozesh
- Department of Chemistry, Xavier University of Louisiana, 1 Drexel Drive, New Orleans, LA, 70125, USA
| | - Zhiqiang Qin
- Department of Pathology, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, 4301 W Markham St, Little Rock, AR, 72205, USA. .,Department of Pediatrics, East Hospital, Tongji University School of Medicine, 200120, Shanghai, China. .,Research Center for Translational Medicine and Key Laboratory of Arrhythmias, East Hospital, Tongji University School of Medicine, 200120, Shanghai, China.
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20
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Attermann A, Bjerregaard AM, Saini S, Grønbæk K, Hadrup S. Human endogenous retroviruses and their implication for immunotherapeutics of cancer. Ann Oncol 2018; 29:2183-2191. [DOI: 10.1093/annonc/mdy413] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Bronkhorst AJ, Wentzel JF, Ungerer V, Peters DL, Aucamp J, de Villiers EP, Holdenrieder S, Pretorius PJ. Sequence analysis of cell-free DNA derived from cultured human bone osteosarcoma (143B) cells. Tumour Biol 2018; 40:1010428318801190. [PMID: 30261820 DOI: 10.1177/1010428318801190] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The true importance of cell-free DNA in human biology, together with the potential scale of its clinical utility, is tarnished by a lack of understanding of its composition and origin. In investigating the cell-free DNA present in the growth medium of cultured 143B cells, we previously demonstrated that the majority of cell-free DNA is neither a product of apoptosis nor necrosis. In the present study, we investigated the composition and origin of this cell-free DNA population using next-generation sequencing. We found that the cell-free DNA comprises mainly of repetitive DNA, including α-satellite DNA, mini satellites, and transposons that are currently active or exhibit the capacity to become reactivated. A significant portion of these cell-free DNA fragments originates from specific chromosomes, especially chromosomes 1 and 9. In healthy adult somatic cells, the centromeric and pericentromeric regions of these chromosomes are normally densely methylated. However, in many cancer types, these regions are preferentially hypomethylated. This can lead to double-stranded DNA breaks or it can directly impair the formation of proper kinetochore structures. This type of chromosomal instability is a precursor to the formation of nuclear anomalies, including lagging chromosomes and anaphase bridges. DNA fragments derived from these structures can recruit their own nuclear envelope and form secondary nuclear structures known as micronuclei, which can localize to the nuclear periphery and bud out from the membrane. We postulate that the majority of cell-free DNA present in the growth medium of cultured 143B cells originates from these micronuclei.
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Affiliation(s)
- Abel Jacobus Bronkhorst
- 1 Institute for Laboratory Medicine, German Heart Centre, Technical University Munich, Munich, Germany
| | - Johannes F Wentzel
- 2 Centre of Excellence for Nutrition (CEN), North-West University, Potchefstroom, South Africa
| | - Vida Ungerer
- 1 Institute for Laboratory Medicine, German Heart Centre, Technical University Munich, Munich, Germany
| | - Dimetrie L Peters
- 3 Human Metabolomics, Biochemistry Division, North-West University, Potchefstroom, South Africa
| | - Janine Aucamp
- 4 Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom, South Africa
| | | | - Stefan Holdenrieder
- 1 Institute for Laboratory Medicine, German Heart Centre, Technical University Munich, Munich, Germany
| | - Piet J Pretorius
- 3 Human Metabolomics, Biochemistry Division, North-West University, Potchefstroom, South Africa
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22
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Kassiotis G, Stoye JP. Making a virtue of necessity: the pleiotropic role of human endogenous retroviruses in cancer. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0277. [PMID: 28893944 PMCID: PMC5597744 DOI: 10.1098/rstb.2016.0277] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/09/2017] [Indexed: 12/18/2022] Open
Abstract
Like all other mammals, humans harbour an astonishing number of endogenous retroviruses (ERVs), as well as other retroelements, embedded in their genome. These remnants of ancestral germline infection with distinct exogenous retroviruses display various degrees of open reading frame integrity and replication capability. Modern day exogenous retroviruses, as well as the infectious predecessors of ERVs, are demonstrably oncogenic. Further, replication-competent ERVs continue to cause cancers in many other species of mammal. Moreover, human cancers are characterized by transcriptional activation of human endogenous retroviruses (HERVs). These observations conspire to incriminate HERVs as causative agents of human cancer. However, exhaustive investigation of cancer genomes suggests that HERVs have entirely lost the ability for re-infection and thus the potential for insertional mutagenic activity. Although there may be non-insertional mechanisms by which HERVs contribute to cancer development, recent evidence also uncovers potent anti-tumour activities exerted by HERV replication intermediates or protein products. On balance, it appears that HERVs, despite their oncogenic past, now represent potential targets for immune-mediated anti-tumour mechanisms. This article is part of the themed issue ‘Human oncogenic viruses’.
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Affiliation(s)
- George Kassiotis
- Retroviral Immunology, The Francis Crick Institute, London, UK .,Department of Medicine, Faculty of Medicine, Imperial College London, London, UK
| | - Jonathan P Stoye
- Retrovirus-Host Interactions, The Francis Crick Institute, London, UK .,Department of Medicine, Faculty of Medicine, Imperial College London, London, UK
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Kim HJ, Moon BI, Lee JW, Kim SC, Kim HJ. Age-related reduction of antibody response against the human endogenous retrovirus K envelope in women. Oncotarget 2017; 7:17327-37. [PMID: 26872058 PMCID: PMC4951215 DOI: 10.18632/oncotarget.7307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 01/29/2016] [Indexed: 01/14/2023] Open
Abstract
In the present study, the correlation between the antibody response against human endogenous retrovirus K (HERV-K) envelope and human age was investigated. Antibody levels were compared in groups in their 20s (n = 25), 30s (n = 39), 40s (n = 68), 50s (n = 32), and 60s and over (n = 25), which included healthy individuals and breast cancer and/or cervical cancer patients. It appeared that both IgM and IgG responses against the HERV-K envelope fell with increasing age. There were no differences in anti-HERV-K envelope antibody levels between healthy individuals and cancer patients. Therefore, our results indicated that the anti-HERV-K antibody levels cannot be considered as cancer-specific marker. Also, IgG1 appeared to be the predominant subtype in the reduction of the IgG response by age. Receiver operating characteristic curves of anti-HERV-K envelope IgM levels indicated that the groups of people in their 20s or 30s could be distinguished from those in their 40s, 50s or 60s and over with satisfactory sensitivity and specificity. These findings indicate that the serum antibody level of HERV-K envelope is a critical parameter reflecting person's age.
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Affiliation(s)
- Hyoung Jin Kim
- Laboratory of Virology, College of Pharmacy, Chung-Ang University, Dongjak-Gu, Seoul 06974, South Korea
| | - Byung-In Moon
- Breast and Thyroid Cancer Center, Ewha Womans University College of Medicine, Yangcheon-Gu, Seoul 07985, South Korea
| | - Jun Woo Lee
- Breast and Thyroid Cancer Center, Ewha Womans University College of Medicine, Yangcheon-Gu, Seoul 07985, South Korea
| | - Seung Cheol Kim
- Department of Obstetrics and Gynecology, Ewha Womans University College of Medicine, Yangcheon-Gu, Seoul 07985, South Korea
| | - Hong-Jin Kim
- Laboratory of Virology, College of Pharmacy, Chung-Ang University, Dongjak-Gu, Seoul 06974, South Korea
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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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25
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Fava P, Bergallo M, Astrua C, Brizio M, Galliano I, Montanari P, Tovo PA, Novelli M, Savoia P, Quaglino P, Fierro MT. Human Endogenous Retrovirus Expression in Primary Cutaneous T-Cell Lymphomas. Dermatology 2015; 232:38-43. [DOI: 10.1159/000438669] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 07/12/2015] [Indexed: 11/19/2022] Open
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26
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Suntsova M, Garazha A, Ivanova A, Kaminsky D, Zhavoronkov A, Buzdin A. Molecular functions of human endogenous retroviruses in health and disease. Cell Mol Life Sci 2015; 72:3653-75. [PMID: 26082181 PMCID: PMC11113533 DOI: 10.1007/s00018-015-1947-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 05/29/2015] [Accepted: 06/03/2015] [Indexed: 12/13/2022]
Abstract
Human endogenous retroviruses (HERVs) and related genetic elements form 504 distinct families and occupy ~8% of human genome. Recent success of high-throughput experimental technologies facilitated understanding functional impact of HERVs for molecular machinery of human cells. HERVs encode active retroviral proteins, which may exert important physiological functions in the body, but also may be involved in the progression of cancer and numerous human autoimmune, neurological and infectious diseases. The spectrum of related malignancies includes, but not limits to, multiple sclerosis, psoriasis, lupus, schizophrenia, multiple cancer types and HIV. In addition, HERVs regulate expression of the neighboring host genes and modify genomic regulatory landscape, e.g., by providing regulatory modules like transcription factor binding sites (TFBS). Indeed, recent bioinformatic profiling identified ~110,000 regulatory active HERV elements, which formed at least ~320,000 human TFBS. These and other peculiarities of HERVs might have played an important role in human evolution and speciation. In this paper, we focus on the current progress in understanding of normal and pathological molecular niches of HERVs, on their implications in human evolution, normal physiology and disease. We also review the available databases dealing with various aspects of HERV genetics.
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Affiliation(s)
- Maria Suntsova
- Group for Genomic Regulation of Cell Signaling Systems, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia.
- Laboratory of Bioinformatics, D. Rogachyov Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, 117198, Russia.
| | - Andrew Garazha
- Group for Genomic Regulation of Cell Signaling Systems, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia.
- Laboratory of Bioinformatics, D. Rogachyov Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, 117198, Russia.
| | - Alena Ivanova
- Group for Genomic Regulation of Cell Signaling Systems, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia.
- Pathway Pharmaceuticals, Wan Chai, Hong Kong, Hong Kong SAR.
| | - Dmitry Kaminsky
- Pathway Pharmaceuticals, Wan Chai, Hong Kong, Hong Kong SAR.
| | - Alex Zhavoronkov
- Pathway Pharmaceuticals, Wan Chai, Hong Kong, Hong Kong SAR.
- Department of Translational and Regenerative Medicine, Moscow Institute of Physics and Technology, 9 Institutskiy per., Dolgoprudny, Moscow, 141700, Russia.
| | - Anton Buzdin
- Group for Genomic Regulation of Cell Signaling Systems, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia.
- Pathway Pharmaceuticals, Wan Chai, Hong Kong, Hong Kong SAR.
- National Research Centre "Kurchatov Institute", Centre for Convergence of Nano-, Bio-, Information and Cognitive Sciences and Technologies, 1, Akademika Kurchatova sq., Moscow, 123182, Russia.
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Differential expression of HERV-K (HML-2) proviruses in cells and virions of the teratocarcinoma cell line Tera-1. Viruses 2015; 7:939-68. [PMID: 25746218 PMCID: PMC4379556 DOI: 10.3390/v7030939] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/09/2015] [Accepted: 02/19/2015] [Indexed: 01/12/2023] Open
Abstract
Human endogenous retrovirus (HERV-K (HML-2)) proviruses are among the few endogenous retroviral elements in the human genome that retain coding sequence. HML-2 expression has been widely associated with human disease states, including different types of cancers as well as with HIV-1 infection. Understanding of the potential impact of this expression requires that it be annotated at the proviral level. Here, we utilized the high throughput capabilities of next-generation sequencing to profile HML-2 expression at the level of individual proviruses and secreted virions in the teratocarcinoma cell line Tera-1. We identified well-defined expression patterns, with transcripts emanating primarily from two proviruses located on chromosome 22, only one of which was efficiently packaged. Interestingly, there was a preference for transcripts of recently integrated proviruses, over those from other highly expressed but older elements, to be packaged into virions. We also assessed the promoter competence of the 5’ long terminal repeats (LTRs) of expressed proviruses via a luciferase assay following transfection of Tera-1 cells. Consistent with the RNASeq results, we found that the activity of most LTRs corresponded to their transcript levels.
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Fuchs NV, Loewer S, Daley GQ, Izsvák Z, Löwer J, Löwer R. Human endogenous retrovirus K (HML-2) RNA and protein expression is a marker for human embryonic and induced pluripotent stem cells. Retrovirology 2013; 10:115. [PMID: 24156636 PMCID: PMC3819666 DOI: 10.1186/1742-4690-10-115] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 09/29/2013] [Indexed: 11/30/2022] Open
Abstract
Background Malignant human embryonal carcinoma cells (ECCs) rely on similar transcriptional networks as non-malignant embryonic stem cells (ESCs) to control selfrenewal, maintain pluripotency, and inhibit differentiation. Because re-activation of silenced HERV-K(HML-2) loci is a hallmark of ECCs, we asked if this HERV group was also reactivated in ESCs and induced pluripotent stem cells (iPSCs). Findings Using RT-PCR and Western Blot, we demonstrate HERV-K(HML-2) RNA and protein expression in undifferentiated human ESCs and iPSCs. Induction of differentiation by embryoid body formation resulted in rapid silencing of HERV-K(HML-2) provirus expression. Sequencing analysis of a conserved region of the gag gene showed that proviral expression in ESCs and iPSCs represents at least 11 of the 66 nearly full length HERV-K(HML-2) loci, with slightly varying patterns in individual cell lines. These proviruses are human specific integrations and harbor promoter competent long terminal repeats (LTR5hs subgroup). We observed high mRNA levels of the NP9 and Gag encoding proviruses K101(22q11.21) in all and K10(5q33.3) in most of the ECC, ESC, and iPSC lines tested, while K37(11q23.3) mRNA was detected only in ESCs and iPSCs. In addition, we detected expression of proviral mRNA encoding the RNA export adaptor Rec in all cell lines studied. Proviral mRNA originating from the K108(7p22.1) locus, which inter alia codes for functional Rec and Env proteins, was only reactivated in malignant ECC lines, not in benign ESCs or iPSCs. Conclusions HERV-K(HML-2) RNA and protein expression is a marker for pluripotent human stem cells. Initiation of differentiation results in rapid down-regulation. Further studies are needed to explore a putative functional role of HERV-K(HML-2) RNA and proteins in pluripotent stem cells.
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Affiliation(s)
- Nina V Fuchs
- Paul-Ehrlich-Institute, Federal Institute for Vaccines and Biomedicines, Paul-Ehrlich-Str, 51-59, D- 63225 Langen, Germany.
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Hohn O, Hanke K, Bannert N. HERV-K(HML-2), the Best Preserved Family of HERVs: Endogenization, Expression, and Implications in Health and Disease. Front Oncol 2013; 3:246. [PMID: 24066280 PMCID: PMC3778440 DOI: 10.3389/fonc.2013.00246] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 09/05/2013] [Indexed: 12/14/2022] Open
Abstract
Retroviruses that have the ability to infect germ line cells can become an integral and inherited part of the host genome. About 8% of the human chromosomal DNA consists of sequences derived from infections by retroviruses that presumably circulated 2-40 millions of years ago, and some elements are actually much older. Post-insertional recombinations, deletions, and mutations have rendered all known human endogenous retroviruses (HERVs) non-infectious. However some, particularly the most recently acquired proviruses of the HERV-K(HML-2) family, can expresses viral proteins and produce viral particles. In this review we will first discuss the major aspects of the endogenization process and peculiarities of the different HERV-K families. We will then focus on the genes and proteins encoded by HERV-K(HML-2) as well as inactivation of these proviruses by postinsertional mutations and their inhibition by antiretroviral factors. After describing the evolutionary interplay between host and endogenous retrovirus we will delve deeper into the currently limited understanding of HERV-K and its possible association with disease, particularly tumorigenesis.
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Affiliation(s)
- Oliver Hohn
- Division for HIV and Other Retroviruses, Robert Koch Institute , Berlin , Germany
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Wang-Johanning F, Li M, Esteva FJ, Hess KR, Yin B, Rycaj K, Plummer JB, Garza JG, Ambs S, Johanning GL. Human endogenous retrovirus type K antibodies and mRNA as serum biomarkers of early-stage breast cancer. Int J Cancer 2013; 134:587-95. [PMID: 23873154 DOI: 10.1002/ijc.28389] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 06/21/2013] [Accepted: 06/28/2013] [Indexed: 01/10/2023]
Abstract
A simple and accurate test to detect early-stage breast cancer has not been developed. Previous studies indicate that the level of human endogenous retrovirus type K (group HERV-K(HML-2)) transcription may be increased in human breast tumors. We hypothesized that HERV-K(HML-2) reactivation can serve as a biomarker for early detection of breast cancer. Serum samples were collected from women without cancer (controls) and patients with ductal carcinoma in situ (DCIS) and invasive breast cancer. ELISA assays were used to detect serum anti-HERV-K(HML-2) antibody titers. RNA was extracted from sera and analyzed by real-time RT-PCR to quantitate the level of HERV-K(HML-2) mRNA. We measured significantly higher serum mRNA and serum antibody titers against HERV-K(HML-2) proteins in women with DCIS and stage I disease than in women without cancer. At optimized cutoffs for the antibody titers, the assay produced an area under the receiver operating characteristic curve (AUC) of 0.89 (95% confidence interval 0.77-1.00) for DCIS and of 0.95 (95% confidence interval 0.89-1.00) for invasive breast cancer. These AUCs are comparable to those observed for mammograms. We also found that serum HERV-K(HML-2) mRNA tended to be higher in breast cancer patients with a primary tumor who later on developed the metastatic disease than in patients who did not develop cancer metastasis. Our results show that HERV-K(HML-2) antibodies and mRNA are already elevated in the blood at an early stage of breast cancer, and further increase in patients who are at risk of developing a metastatic disease.
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Affiliation(s)
- Feng Wang-Johanning
- Department of Veterinary Sciences, The University of Texas M.D. Anderson Cancer Center, Houston, TX; Department of Immunology, The University of Texas M.D. Anderson Cancer Center, Houston, TX; Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, TX
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Vaccination directed against the human endogenous retrovirus-K envelope protein inhibits tumor growth in a murine model system. PLoS One 2013; 8:e72756. [PMID: 24023643 PMCID: PMC3758348 DOI: 10.1371/journal.pone.0072756] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 07/12/2013] [Indexed: 01/01/2023] Open
Abstract
Human endogenous retrovirus (HERV) genomes are chromosomally integrated in all cells of an individual. They are normally transcriptionally silenced and transmitted only vertically. Enhanced expression of HERV-K accompanied by the emergence of anti-HERV-K-directed immune responses has been observed in tumor patients and HIV-infected individuals. As HERV-K is usually not expressed and immunological tolerance development is unlikely, it is an appropriate target for the development of immunotherapies. We generated a recombinant vaccinia virus (MVA-HKenv) expressing the HERV-K envelope glycoprotein (ENV), based on the modified vaccinia virus Ankara (MVA), and established an animal model to test its vaccination efficacy. Murine renal carcinoma cells (Renca) were genetically altered to express E. coli beta-galactosidase (RLZ cells) or the HERV-K ENV gene (RLZ-HKenv cells). Intravenous injection of RLZ-HKenv cells into syngenic BALB/c mice led to the formation of pulmonary metastases, which were detectable by X-gal staining. A single vaccination of tumor-bearing mice with MVA-HKenv drastically reduced the number of pulmonary RLZ-HKenv tumor nodules compared to vaccination with wild-type MVA. Prophylactic vaccination of mice with MVA-HKenv precluded the formation of RLZ-HKenv tumor nodules, whereas wild-type MVA-vaccinated animals succumbed to metastasis. Protection from tumor formation correlated with enhanced HERV-K ENV-specific killing activity of splenocytes. These data demonstrate for the first time that HERV-K ENV is a useful target for vaccine development and might offer new treatment opportunities for diverse types of cancer.
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Young GR, Ploquin MJY, Eksmond U, Wadwa M, Stoye JP, Kassiotis G. Negative selection by an endogenous retrovirus promotes a higher-avidity CD4+ T cell response to retroviral infection. PLoS Pathog 2012; 8:e1002709. [PMID: 22589728 PMCID: PMC3349761 DOI: 10.1371/journal.ppat.1002709] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 04/04/2012] [Indexed: 11/18/2022] Open
Abstract
Effective T cell responses can decisively influence the outcome of retroviral infection. However, what constitutes protective T cell responses or determines the ability of the host to mount such responses is incompletely understood. Here we studied the requirements for development and induction of CD4+ T cells that were essential for immunity to Friend virus (FV) infection of mice, according to their TCR avidity for an FV-derived epitope. We showed that a self peptide, encoded by an endogenous retrovirus, negatively selected a significant fraction of polyclonal FV-specific CD4+ T cells and diminished the response to FV infection. Surprisingly, however, CD4+ T cell-mediated antiviral activity was fully preserved. Detailed repertoire analysis revealed that clones with low avidity for FV-derived peptides were more cross-reactive with self peptides and were consequently preferentially deleted. Negative selection of low-avidity FV-reactive CD4+ T cells was responsible for the dominance of high-avidity clones in the response to FV infection, suggesting that protection against the primary infecting virus was mediated exclusively by high-avidity CD4+ T cells. Thus, although negative selection reduced the size and cross-reactivity of the available FV-reactive naïve CD4+ T cell repertoire, it increased the overall avidity of the repertoire that responded to infection. These findings demonstrate that self proteins expressed by replication-defective endogenous retroviruses can heavily influence the formation of the TCR repertoire reactive with exogenous retroviruses and determine the avidity of the response to retroviral infection. Given the overabundance of endogenous retroviruses in the human genome, these findings also suggest that endogenous retroviral proteins, presented by products of highly polymorphic HLA alleles, may shape the human TCR repertoire that reacts with exogenous retroviruses or other infecting pathogens, leading to interindividual heterogeneity.
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Affiliation(s)
- George R. Young
- Division of Immunoregulation, MRC National Institute for Medical Research, London, United Kingdom
| | - Mickaël J.-Y. Ploquin
- Division of Immunoregulation, MRC National Institute for Medical Research, London, United Kingdom
| | - Urszula Eksmond
- Division of Immunoregulation, MRC National Institute for Medical Research, London, United Kingdom
| | - Munisch Wadwa
- Division of Immunoregulation, MRC National Institute for Medical Research, London, United Kingdom
| | - Jonathan P. Stoye
- Division of Virology, MRC National Institute for Medical Research, London, United Kingdom
| | - George Kassiotis
- Division of Immunoregulation, MRC National Institute for Medical Research, London, United Kingdom
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Wang-Johanning F, Rycaj K, Plummer JB, Li M, Yin B, Frerich K, Garza JG, Shen J, Lin K, Yan P, Glynn SA, Dorsey TH, Hunt KK, Ambs S, Johanning GL. Immunotherapeutic potential of anti-human endogenous retrovirus-K envelope protein antibodies in targeting breast tumors. J Natl Cancer Inst 2012; 104:189-210. [PMID: 22247020 DOI: 10.1093/jnci/djr540] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The envelope (env) protein of the human endogenous retrovirus type K (HERV-K) family is commonly expressed on the surface of breast cancer cells. We assessed whether HERV-K env is a potential target for antibody-based immunotherapy of breast cancer. METHODS We examined the expression of HERV-K env protein in various malignant (MDA-MB-231, MCF-7, SKBR3, MDA-MB-453, T47D, and ZR-75-1) and nonmalignant (MCF-10A and MCF-10AT) human breast cell lines by immunoblot, enzyme-linked immunosorbent assay, immunofluorescence staining, and flow cytometry. Anti-HERV-K env monoclonal antibodies (mAbs; 6H5, 4D1, 4E11, 6E11, and 4E6) were used to target expression of HERV-K, and antitumor effects were assessed by quantifying growth and apoptosis of breast cancer cells in vitro, and tumor growth in vivo in mice (n = 5 per group) bearing xenograft tumors. The mechanisms responsible for 6H5 mAb-mediated effects were investigated by microarray assays, flow cytometry, immunoblot, and immunofluorescence staining. The expression of HERV-K env protein was assessed in primary breast tumors (n = 223) by immunohistochemistry. All statistical tests were two-sided. RESULTS The expression of HERV-K env protein in malignant breast cancer cell lines was substantially higher than nonmalignant breast cells. Anti-HERV-K-specific mAbs inhibited growth and induced apoptosis of breast cancer cells in vitro. Mice treated with 6H5 mAb showed statistically significantly reduced growth of xenograft tumors compared with mice treated with control immunoglobulin (control [mIgG] vs 6H5 mAb, for tumors originating from MDA-MB-231 cells, mean size = 1448.33 vs 475.44 mm(3); difference = 972.89 mm(3), 95% CI = 470.17 to 1475.61 mm(3); P < .001). Several proteins involved in the apoptotic signaling pathways were overexpressed in vitro in 6H5 mAb-treated malignant breast cells compared with mIgG-treated control. HERV-K expression was detected in 148 (66%) of 223 primary breast tumors, and a higher rate of lymph node metastasis was associated with HERV-K-positive compared with HERV-K-negative tumors (43% vs 23%, P = .003). CONCLUSION Monoclonal antibodies against HERV-K env protein show potential as novel immunotherapeutic agents for breast cancer therapy.
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Affiliation(s)
- Feng Wang-Johanning
- Department of Veterinary Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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Tumour microvesicles contain retrotransposon elements and amplified oncogene sequences. Nat Commun 2011; 2:180. [PMID: 21285958 DOI: 10.1038/ncomms1180] [Citation(s) in RCA: 868] [Impact Index Per Article: 66.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 01/07/2011] [Indexed: 12/14/2022] Open
Abstract
Tumour cells release an abundance of microvesicles containing a selected set of proteins and RNAs. Here, we show that tumour microvesicles also carry DNA, which reflects the genetic status of the tumour, including amplification of the oncogene c-Myc. We also find amplified c-Myc in serum microvesicles from tumour-bearing mice. Further, we find remarkably high levels of retrotransposon RNA transcripts, especially for some human endogenous retroviruses, such as LINE-1 and Alu retrotransposon elements, in tumour microvesicles and these transposable elements could be transferred to normal cells. These findings expand the nucleic acid content of tumour microvesicles to include: elevated levels of specific coding and non-coding RNA and DNA, mutated and amplified oncogene sequences and transposable elements. Thus, tumour microvesicles contain a repertoire of genetic information available for horizontal gene transfer and potential use as blood biomarkers for cancer.
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Expression of the human endogenous retrovirus (HERV) group HML-2/HERV-K does not depend on canonical promoter elements but is regulated by transcription factors Sp1 and Sp3. J Virol 2011; 85:3436-48. [PMID: 21248046 DOI: 10.1128/jvi.02539-10] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
After fixation in the human genome, human endogenous retroviruses (HERVs) are bona fide cellular genes despite their exogenous origin. To be able to spread within the germ line and the early embryo, the ancient retroviral promoters must have adapted to the requirements for expression in these cell types. We describe that in contrast to the case for current exogenous retroviruses, which replicate in specific somatic cells, the long terminal repeat (LTR) of the human endogenous retrovirus HERV-K acts as a TATA- and initiator element-independent promoter with a variable transcription start site. We present evidence that the HERV-K LTR is regulated by the transcription factors Sp1 and Sp3. Mutating specific GC boxes, which are binding sites for Sp proteins, and knocking down Sp1 and Sp3 by use of small interfering RNA (siRNA) significantly reduced the promoter activity. Binding of Sp1 and Sp3 to the promoter region was confirmed using electrophoretic mobility shift assays (EMSAs) and chromatin immunoprecipitation (ChIP). Our data explain why certain HERV-K proviruses have lost promoter competence. Since vertebrate promoters lacking canonical core promoter elements are common but poorly studied, understanding the HERV-K promoter not only will provide insight into the regulation of endogenous retroviruses but also can serve as a paradigm for understanding the regulation of this class of cellular genes.
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Do infantile testicular germ cell tumors histogenetically develop from conventional intratubular germ cell neoplasia? Urol Oncol 2010; 29:1-3. [PMID: 20870431 DOI: 10.1016/j.urolonc.2010.04.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 04/14/2010] [Accepted: 04/26/2010] [Indexed: 11/20/2022]
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Romanish MT, Cohen CJ, Mager DL. Potential mechanisms of endogenous retroviral-mediated genomic instability in human cancer. Semin Cancer Biol 2010; 20:246-53. [PMID: 20685251 DOI: 10.1016/j.semcancer.2010.05.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 05/12/2010] [Accepted: 05/19/2010] [Indexed: 01/13/2023]
Abstract
Malignancy results from a complex combination of genetic and epigenetic changes, the full effects of which are still largely unknown. Here we summarize current knowledge of the origin, retrotranspositional activity, epigenetic state, and transcription of human endogenous retroviruses (HERVs), and then discuss the potential effects of their deregulation in cancer. Evidence suggests that cancer-associated epigenetic changes most likely underlie potential HERV-mediated effects on genome and transcriptome instability and may play a role in malignancy. Despite our currently limited understanding of the importance of HERVs or other transposable elements in cancer development, we believe that the emerging era of high-throughput sequencing of cancer genomes, epigenomes, and transcriptomes will provide unprecedented opportunities to investigate these roles in the future.
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Affiliation(s)
- M T Romanish
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada.
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Singh S, Kaye S, Gore ME, McClure MO, Bunker CB. The role of human endogenous retroviruses in melanoma. Br J Dermatol 2009; 161:1225-31. [PMID: 19785608 DOI: 10.1111/j.1365-2133.2009.09415.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sequencing of the human genome has established that our DNA harbours many endogenous retrovirus (ERV) sequences, remnants of ancestral exogenous retroviral infections fixed in the germline DNA. In recent years, human ERVs (HERVs) have been implicated in melanomagenesis. Retrovirus-like particles and the expression of HERV mRNA and proteins have been demonstrated in melanoma tissue. In addition, antibodies to HERV proteins have been observed in patients with melanoma. In vitro and mouse models have provided fascinating insights into the potential mechanisms of HERVs in melanomagenesis. This review considers the evidence associating HERVs with melanoma.
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Affiliation(s)
- S Singh
- Department of Dermatology, Chelsea and Westminster Hospital, Imperial College Faculty of Medicine, London, U.K.
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Ruggieri A, Maldener E, Sauter M, Mueller-Lantzsch N, Meese E, Fackler OT, Mayer J. Human endogenous retrovirus HERV-K(HML-2) encodes a stable signal peptide with biological properties distinct from Rec. Retrovirology 2009; 6:17. [PMID: 19220907 PMCID: PMC2649029 DOI: 10.1186/1742-4690-6-17] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Accepted: 02/16/2009] [Indexed: 11/26/2022] Open
Abstract
Background The human endogenous retrovirus HERV-K(HML-2) family is associated with testicular germ cell tumors (GCT). Various HML-2 proviruses encode viral proteins such as Env and Rec. Results We describe here that HML-2 Env gives rise to a 13 kDa signal peptide (SP) that harbors a different C-terminus compared to Rec. Subsequent to guiding Env to the endoplasmatic reticulum (ER), HML-2 SP is released into the cytosol. Biochemical analysis and confocal microscopy demonstrated that similar to Rec, SP efficiently translocates to the granular component of nucleoli. Unlike Rec, SP does not shuttle between nucleus and cytoplasm. SP is less stable than Rec as it is subjected to proteasomal degradation. Moreover, SP lacks export activity towards HML-2 genomic RNA, the main function of Rec in the original viral context, and SP does not interfere with Rec's RNA export activity. Conclusion SP is a previously unrecognized HML-2 protein that, besides targeting and translocation of Env into the ER lumen, may exert biological functions distinct from Rec. HML-2 SP represents another functional similarity with the closely related Mouse Mammary Tumor Virus that encodes an Env-derived SP named p14. Our findings furthermore support the emerging concept of bioactive SPs as a conserved retroviral strategy to modulate their host cell environment, evidenced here by a "retroviral fossil". While the specific role of HML-2 SP remains to be elucidated in the context of human biology, we speculate that it may be involved in immune evasion of GCT cells or tumorigenesis.
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Affiliation(s)
- Alessia Ruggieri
- Department of Human Genetics, Medical Faculty, University of Saarland, Homburg, Germany.
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Hahn S, Ugurel S, Hanschmann KM, Strobel H, Tondera C, Schadendorf D, Löwer J, Löwer R. Serological response to human endogenous retrovirus K in melanoma patients correlates with survival probability. AIDS Res Hum Retroviruses 2008; 24:717-23. [PMID: 18462078 DOI: 10.1089/aid.2007.0286] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
A few years ago, reactivation of human endogenous retrovirus K (HERV-K) proviruses in melanoma was described. The expression of HERV-K proteins induces humoral immune responses. The aim of the present study was to elucidate the prognostic relevance of serological anti-HERV-K reactivity in melanoma patients. In a retrospective study, anti-HERV-K Gag and Env antibodies were detected in 51 of the 312 randomly selected and blinded sera from melanoma patients, but not in any of the 70 sera from healthy controls. Comparing serological HERV-K reactivity with established melanoma markers revealed a significant correlation (p = 0.018, Chi-square test) with the stage of disease classified according to the American Joint Committee on Cancer (AJCC). Anti-HERV-K reactivity was elevated in patients with acrolentiginous/mucosal/uveal melanoma (tumor subtypes developing at sun-protected sites) compared to patients with lentigo/nodular/superficial spreading melanoma (p = 0.011, Chi-square test). Patients with anti-HERV-K antibodies had a significantly decreased disease-specific overall survival (stage I-IV, p < 0.001; stage I-III, p = 0.005, log-rank test). Significantly, multivariate Cox regression analysis including prognostic markers in clinical use (e.g., AJCC stage, T-class, serum level of S100-beta) revealed serological HERV-K reactivity as an independent marker of reduced survival probability (p = 0.027) in melanoma patients with the early stages of the disease (AJCC I-III). This is the first report that the humoral anti-HERV-K immune response may provide additional prognostic information to that of established melanoma markers.
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Affiliation(s)
- Silvia Hahn
- Retroelement Section, Paul-Ehrlich-Institut, Langen, Germany
| | - Selma Ugurel
- Retroelement Section, Paul-Ehrlich-Institut, Langen, Germany
- Skin Cancer Unit, German Cancer Research Center Heidelberg/Department of Dermatology, University Hospital of Mannheim, Mannheim, Germany
- Present address: Department of Dermatology, University Clinic of Würzburg, Würzburg, Germany
| | | | - Heike Strobel
- Retroelement Section, Paul-Ehrlich-Institut, Langen, Germany
| | | | - Dirk Schadendorf
- Skin Cancer Unit, German Cancer Research Center Heidelberg/Department of Dermatology, University Hospital of Mannheim, Mannheim, Germany
| | - Johannes Löwer
- Retroelement Section, Paul-Ehrlich-Institut, Langen, Germany
| | - Roswitha Löwer
- Retroelement Section, Paul-Ehrlich-Institut, Langen, Germany
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Boller K, Schönfeld K, Lischer S, Fischer N, Hoffmann A, Kurth R, Tönjes RR. Human endogenous retrovirus HERV-K113 is capable of producing intact viral particles. J Gen Virol 2008; 89:567-572. [PMID: 18198388 DOI: 10.1099/vir.0.83534-0] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Of all human endogenous retroviruses known today, HERV-K is the only one that has been shown to produce viral particles. While the first of the approximately 30 HERV-K sequences integrated into the human genome more than 40 million years ago, evidence is accumulating that HERV-K was active more recently, provirus HERV-K113 being the youngest sequence found. However, it is unclear which HERV-K sequences code for the viral particles that are produced by human germ-cell tumours or melanomas. Here, we show that the provirus HERV-K113, cloned into a baculovirus expression vector, is capable of producing intact particles of retroviral morphology, exhibiting the typical structure of those particles that were characterized in cell lines derived from human germ-cell tumours. Thus, the HERV-K113 sequence is a candidate for particle production in vivo and for an active human endogenous retrovirus of today.
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Affiliation(s)
- Klaus Boller
- Paul-Ehrlich-Institut, Paul-Ehrlich-Straße 51-59, D-63225 Langen, Germany
| | - Kurt Schönfeld
- Paul-Ehrlich-Institut, Paul-Ehrlich-Straße 51-59, D-63225 Langen, Germany
| | - Stefanie Lischer
- Paul-Ehrlich-Institut, Paul-Ehrlich-Straße 51-59, D-63225 Langen, Germany
| | - Nicole Fischer
- Paul-Ehrlich-Institut, Paul-Ehrlich-Straße 51-59, D-63225 Langen, Germany
| | - Andreas Hoffmann
- Paul-Ehrlich-Institut, Paul-Ehrlich-Straße 51-59, D-63225 Langen, Germany
| | - Reinhard Kurth
- Robert Koch-Institut, Nordufer 20, D-13353 Berlin, Germany
| | - Ralf R Tönjes
- Paul-Ehrlich-Institut, Paul-Ehrlich-Straße 51-59, D-63225 Langen, Germany
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Voisset C, Weiss RA, Griffiths DJ. Human RNA "rumor" viruses: the search for novel human retroviruses in chronic disease. Microbiol Mol Biol Rev 2008; 72:157-96, table of contents. [PMID: 18322038 PMCID: PMC2268285 DOI: 10.1128/mmbr.00033-07] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Retroviruses are an important group of pathogens that cause a variety of diseases in humans and animals. Four human retroviruses are currently known, including human immunodeficiency virus type 1, which causes AIDS, and human T-lymphotropic virus type 1, which causes cancer and inflammatory disease. For many years, there have been sporadic reports of additional human retroviral infections, particularly in cancer and other chronic diseases. Unfortunately, many of these putative viruses remain unproven and controversial, and some retrovirologists have dismissed them as merely "human rumor viruses." Work in this field was last reviewed in depth in 1984, and since then, the molecular techniques available for identifying and characterizing retroviruses have improved enormously in sensitivity. The advent of PCR in particular has dramatically enhanced our ability to detect novel viral sequences in human tissues. However, DNA amplification techniques have also increased the potential for false-positive detection due to contamination. In addition, the presence of many families of human endogenous retroviruses (HERVs) within our DNA can obstruct attempts to identify and validate novel human retroviruses. Here, we aim to bring together the data on "novel" retroviral infections in humans by critically examining the evidence for those putative viruses that have been linked with disease and the likelihood that they represent genuine human infections. We provide a background to the field and a discussion of potential confounding factors along with some technical guidelines. In addition, some of the difficulties associated with obtaining formal proof of causation for common or ubiquitous agents such as HERVs are discussed.
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Affiliation(s)
- Cécile Voisset
- CNRS-UMR8161, Institut de Biologie de Lille et Institut Pasteur de Lille, Lille, France
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Abstract
The ability to fuse cells is shared by many viruses, including common human pathogens and several endogenous viruses. Here we will discuss how cell fusion can link viruses to cancer, what types of cancers it can affect, how the existence of this link can be tested and how the hypotheses that we propose might affect the search for human oncogenic viruses. In particular, we will focus on the ability of cell fusion that is caused by viruses to induce chromosomal instability, a common affliction of cancer cells that has been thought to underlie the malignant properties of cancerous tumours.
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Affiliation(s)
- Dominik Duelli
- Department of Pathology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois 60064, USA.
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Wang-Johanning F, Huang M, Liu J, Rycaj K, Plummer JB, Barnhart KF, Satterfield WC, Johanning GL. Sheep stromal-epithelial cell interactions and ovarian tumor progression. Int J Cancer 2007; 121:2346-54. [PMID: 17657741 DOI: 10.1002/ijc.22960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Previous studies suggest that underlying ovarian stromal cues may regulate the ovarian surface epithelium. However, little is known about the interaction between ovarian stromal cells (OSC) and ovarian surface epithelial cells (OSE) under normal physiologic and pathologic conditions, largely because of the lack of a suitable model. In the current study, the OSC obtained from a sheep were immortalized with SV-40 T/t antigen (designated IOSC) and telomerase reverse transcriptase (designated IOSCH), followed by transfection with the oncogenic allele of the human H-Ras oncogene (designated IOSChR). IOSC cells transfected with H-Ras before immortalization with telomerase were designated IOSCRH. These sheep OSCs were used in both in vitro and in vivo model systems to evaluate mechanisms by which OSCs influence ovarian tumor progression. Normal sheep OSCs were found to inhibit the growth of SKOV3 and OVCAR3 human ovarian cancer cells, but not normal sheep OSE and human OSE cells (hOSE137 cells). In contrast, IOSChR and IOSCRH cells stimulated the growth of normal sheep and human OSE cells, as well as cancer cells. These findings were confirmed by in vivo studies. Our data provide compelling support for the importance of stromal-epithelial cell interactions during tumor progression, and show for the first time that immortalized and transformed OSCs promote growth of ovarian epithelial tumors.
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Affiliation(s)
- Feng Wang-Johanning
- Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, The University of Texas M.D. Anderson Cancer Center, Bastrop, TX, USA.
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46
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Abstract
OBJECTIVE To address the activation and replicative activity of HERV-K102 in vivo associated with HIV viremia. DESIGN AND METHODS Initially serology was performed on HERV-K102 specific envelope peptides to determine if HERV-K102 may become activated with HIV viremia. Before developing a quantitative PCR (qPCR) assay, we first determined whether plasma associated particles contained DNA or RNA genomes in a pilot study which surprisingly revealed predominantly DNA genomes. A relative, ddCt qPCR ratio method was then devised to detect excess levels of HERV-K102 pol DNA templates over genomic levels which served as a surrogate marker to reliably index the level of particles found in plasma. RESULTS Both the peptide serology and ddCt qPCR excess ratio methods suggested the activation of HERV-K102 in about 70-80% of HIV viremic cases whereas only 2-3% of normal healthy adults had marginally activated HERV-K102 (P < 0.0001). Moreover, by digestion with dUTPase we were able to confirm that the vast majority of excess DNA template in plasma related to cDNA production rather than representing genomic copies. CONCLUSIONS Our work uniquely suggests the common activation of HERV-K102 with HIV viremia and may be first to directly demonstrate HERV-K102 cDNA production in vivo. The potential implications of the induction of HERV-K102 activation and replication for the prevention and control of HIV are discussed.
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47
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Wentzensen N, Coy JF, Knaebel HP, Linnebacher M, Wilz B, Gebert J, von Knebel Doeberitz M. Expression of an endogenous retroviral sequence from the HERV-H group in gastrointestinal cancers. Int J Cancer 2007; 121:1417-23. [PMID: 17546591 DOI: 10.1002/ijc.22826] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Human endogenous retroviruses (HERVs) account for approximately 8% of the human genome. Since the majority of HERV elements have accumulated inactivating mutations in the viral genes, only few expressed viral open reading frames (ORFs) have been described. In this study, we have analyzed the expression of a HERV-H copy located on Xp22.3 encompassing a potential ORF immediately downstream of the viral promoter. Conventional and real time RT-PCR based expression analysis of this specific HERV-H sequence showed overexpression in 16 of 34 (47%) colorectal, 25 of 63 (40%) gastric and 2 of 12 (17%) pancreatic cancers, whereas no overexpression was detected in bronchial and cervical cancers. Normal human testis, placenta and breast tissue did not show expression of this sequence. CpG methylation analysis of the viral promoter revealed a loss of methylation in cell lines expressing the HERV-H sequence as compared to nonexpressing cell lines and lymphocyte DNA derived from healthy individuals. Further investigations of the HERV-H long terminal repeat and the HERV-H RNA are necessary to assess the functional relevance of the HERV-H expression.
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Affiliation(s)
- Nicolas Wentzensen
- Department of Applied Tumor Biology, Institute of Pathology, University of Heidelberg, Heidelberg, Germany.
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48
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Schulz WA, Steinhoff C, Florl AR. Methylation of endogenous human retroelements in health and disease. Curr Top Microbiol Immunol 2006; 310:211-50. [PMID: 16909913 DOI: 10.1007/3-540-31181-5_11] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Retroelements constitute approximately 45% of the human genome. Long interspersed nuclear element (LINE) autonomous retrotransposons are predominantly represented by LINE-1, nonautonomous small interspersed nuclear elements (SINEs) are primarily represented by ALUs, and LTR retrotransposons by several families of human endogenous retroviruses (HERVs). The vast majority of LINE and HERV elements are densely methylated in normal somatic cells and contained in inactive chromatin. Methylation and chromatin structure together ensure a stable equilibrium between retroelements and their host. Hypomethylation and expression in developing germ cells opens a "window of opportunity" for retrotransposition and recombination that contribute to human evolution, but also inherited disease. In somatic cells, the presence of retroelements may be exploited to organize the genome into active and inactive regions, to separate domains and functional regions within one chromatin domain, to suppress transcriptional noise, and to regulate transcript stability. Retroelements, particularly ALUs, may also fulfill physiological roles during responses to stress and infections. Reactivation and hypomethylation of LINEs and HERVs may be important in the pathophysiology of cancer and various autoimmune diseases, contributing to chromosomal instability and chronically aberrant immune responses. The emerging insights into the pathophysiological importance of endogenous retroelements accentuate the gaps in our knowledge of how these elements are controlled in normal developing and mature cells.
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Affiliation(s)
- W A Schulz
- Urologische Klinik, Heinrich Heine Universität, Düsseldorf, Germany.
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49
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Humer J, Waltenberger A, Grassauer A, Kurz M, Valencak J, Rapberger R, Hahn S, Löwer R, Wolff K, Bergmann M, Muster T, Mayer B, Pehamberger H. Identification of a Melanoma Marker Derived from Melanoma-Associated Endogenous Retroviruses. Cancer Res 2006; 66:1658-63. [PMID: 16452225 DOI: 10.1158/0008-5472.can-05-2452] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We previously described the expression of melanoma-associated endogenous retrovirus (MERV) proteins and viral particles in human melanomas and metastases. The objective of the present study was to determine whether a humoral immune response to MERV proteins occurs in melanoma. Candidate B-cell epitopes on MERV proteins were predicted using bioinformatic screening. The reactivity of MERV peptides corresponding to the predicted epitopes with antibodies prevalent in sera of melanoma patients was analyzed. An immunodominant peptide located in the env protein of MERV was identified. Subsequent analyzes using 81 samples from stage I to stage IV melanoma patients and 95 sera from healthy subjects revealed statistically significant differences in seroprevalence of antibodies in melanoma sera samples when compared with reference samples from healthy subjects. The prevalence of anti-MERV antibodies in melanoma patient sera was confirmed by immunofluorescence on env-transfected cells. These data indicate the potential of this candidate peptide as target for diagnosis and immunotherapy.
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Affiliation(s)
- Johannes Humer
- Department of Dermatology, Division of General Dermatology, Green Hills Biotechnology GmbH, Gersthoferstrasse 29-31, 1180 Vienna, Austria
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50
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Rakoff-Nahoum S, Kuebler PJ, Heymann JJ, E Sheehy M, Ortiz GM, S Ogg G, Barbour JD, Lenz J, Steinfeld AD, Nixon DF. Detection of T lymphocytes specific for human endogenous retrovirus K (HERV-K) in patients with seminoma. AIDS Res Hum Retroviruses 2006; 22:52-6. [PMID: 16438646 DOI: 10.1089/aid.2006.22.52] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Human endogenous retrovirus K (HERV-K) is distinctive among the retroviruses that comprise about 8% of the human genome in that multiple HERV-K proviruses encode full-length viral proteins, and many HERV-K proviruses formed during recent human evolution. HERV-K gag proteins are found in the cytoplasm of primary tumor cells of patients with seminoma. We identified HERV-K-specific T cells in patients with a past history of seminoma using the interferon-gamma ELISPOT assay and an MHC-HERV-K peptide-specific tetramer. A minority of apparently healthy subjects without evident germ cell tumors also made HERV-K-specific T cell responses. In summary, we detected T cell reactivity to HERV-K peptides in both past seminoma patients and a minority of apparently healthy controls.
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Affiliation(s)
- Seth Rakoff-Nahoum
- J.D. Gladstone Institutes, Gladstone Institute of Virology and Immunology, San Francisco, California 94158, USA
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