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Fan J, Qin Z. Roles of Human Endogenous Retrovirus-K-Encoded Np9 in Human Diseases: A Small Protein with Big Functions. Viruses 2024; 16:581. [PMID: 38675923 PMCID: PMC11054019 DOI: 10.3390/v16040581] [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: 03/24/2024] [Revised: 04/08/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024] Open
Abstract
Human Endogenous Retrovirus Sequences (HERVs) constitute up to 8% of the human genome, yet not all HERVs remain silent passengers within our genomes. Some HERVs, especially HERV type K (HERV-K), have been found to be frequently transactivated in a variety of inflammatory diseases and human cancers. Np9, a small protein translated from the HERV-K env reading frame, has been reported as an oncogenic protein and is present in a variety of tumors and transformed cells. The Np9 protein can crosstalk with many cellular factors and is involved in the pathogenicity of various diseases, including some oncogenic virus infections. In the current review, we summarize recent findings about Np9 clinical relevance/implications, its mediated cellular functions/mechanisms, and potential targeted therapies in development.
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Affiliation(s)
| | - 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;
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Li T, Qian K, Han J, Liu Y, Jia L, Wang X, Li T, Zhang B, Li J, Li H, Dou L, Li L. Higher Expression of Human Endogenous Retrovirus-K was Observed in Peripheral B Lymphocytes of Leukemia and Lymphoma Patients. AIDS Res Hum Retroviruses 2024; 40:268-279. [PMID: 38009220 DOI: 10.1089/aid.2023.0037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2023] Open
Abstract
Hematological malignant tumors (HMTs) are serious diseases that threaten human health and life with high mortality. Therefore, it is necessary to develop novel strategies for diagnosis and treatment. Human endogenous retroviruses (HERVs) have recently attracted increasing attention as potential targets for cancer diagnosis and therapy. In this study, we explored the association between HERV-K expression levels and HMTs development. Clinical data and peripheral blood samples were collected from 236 leukemia, 384 lymphoma patients, and 69 healthy controls. Quantitative polymerase chain reaction was used to detect the expression of HERV-K gag, pol, and env genes in peripheral blood mononuclear cells or different cell subpopulations. Differently expressed HERV-K genes were further tested by using deep sequencing method, and further analyzed with gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. B cell- and T cell-related cytokines in patients were also detected by enzyme-linked immunosorbent assay (ELISA). The results showed that the expression levels of the HERV-K gag, pol, and env genes in patients were significantly higher than in healthy controls. There was a correlation between the expression level of HERV-K and the clinicopathological parameters of leukemia patients. HERV-K expression was increased in the B lymphocytes of leukemia and lymphoma patients, but not in the T cells or neutrophils. The GO and KEGG analyses showed that abnormal expression of the HERV-K locus in patients affected immune regulation. The analysis of cytokines proved that the B cell-related cytokines, including interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-α, and interferon-gamma, were significantly decreased in patients, while the T cell-related cytokines, including IL-3, IL-12, and TNF-β, were not significantly changed. In conclusion, HERV-K genes might participate in the occurrence and development of leukemia and lymphoma, and might be biomarkers for the detection or evaluation of leukemia and lymphoma.
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Affiliation(s)
- Tianfu Li
- State Key Laboratory of Pathogen and Biosecurity, Department of AIDS Research, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Kun Qian
- Nankai University School of Medicine, Tianjin, China
| | - Jingwan Han
- State Key Laboratory of Pathogen and Biosecurity, Department of AIDS Research, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Yongjian Liu
- State Key Laboratory of Pathogen and Biosecurity, Department of AIDS Research, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Lei Jia
- State Key Laboratory of Pathogen and Biosecurity, Department of AIDS Research, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Xiaolin Wang
- State Key Laboratory of Pathogen and Biosecurity, Department of AIDS Research, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Tianyi Li
- State Key Laboratory of Pathogen and Biosecurity, Department of AIDS Research, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Bohan Zhang
- State Key Laboratory of Pathogen and Biosecurity, Department of AIDS Research, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Jingyun Li
- State Key Laboratory of Pathogen and Biosecurity, Department of AIDS Research, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Hanping Li
- State Key Laboratory of Pathogen and Biosecurity, Department of AIDS Research, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Liping Dou
- Department of Hematology, the Fifth Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Lin Li
- State Key Laboratory of Pathogen and Biosecurity, Department of AIDS Research, Beijing Institute of Microbiology and Epidemiology, Beijing, China
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Gaber N, Abdelhafiz AS, Abdel-Azim N, Shibl A, Fadel L, Hassan ZK, Ahmed EH. HERV-K np9 and HERV-R env: Two endogenous retrovirus products with potential Pathogenic roles in pediatric acute lymphoblastic leukemia. Int J Immunopathol Pharmacol 2024; 38:3946320241274255. [PMID: 39122243 PMCID: PMC11316263 DOI: 10.1177/03946320241274255] [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: 03/02/2024] [Accepted: 07/21/2024] [Indexed: 08/12/2024] Open
Abstract
OBJECTIVES Human endogenous retroviruses (HERVs) are integral components of the human genome, and their reactivation has been implicated in the pathogenesis of some malignancies. External viral co-infections are suspected to play a role in HERV transactivation. This study aimed to investigate the expression of HERV-K np9 elements and HERV-R env gene in pediatric acute lymphoblastic leukemia (ALL) patients. Additionally, we explored potential correlations between HERV expression and common viral infections prevalent in this group of patients. METHODS Blood samples were collected from 43 pediatric ALL patients and 48 age- and sex-matched healthy controls. Quantitative real-time PCR (qRT-PCR) was used to assess the expression of HERV-K np9 and HERV-R env, along with herpes simplex virus (HSV), parvovirus B19, and polyomavirus BK. RESULTS HERV-K np9 and HERV-R env showed significantly higher expression in the peripheral blood of ALL patients compared to healthy controls (p < .001 and p = .003, respectively). HSV positivity was associated with significantly increased HERV-K np9 expression. No significant correlations were observed between other investigated viruses and HERV gene expression. CONCLUSION The overexpression of HERV-K np9 and HERV-R env in pediatric ALL patients suggest their potential role in leukemogenesis. Our findings also suggest a possible link between HSV infection and HERV reactivation in this population. Future investigations are needed to understand the precise roles of these genes and viral infections in the development of ALL.
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Affiliation(s)
- Noha Gaber
- Clinical Pathology Department, South Egypt Cancer Institute, Assiut University, Assiut, Egypt
| | - Ahmed Samir Abdelhafiz
- Clinical Pathology Department, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Nivin Abdel-Azim
- Cancer Biology Department, South Egypt Cancer Institute, Assiut University, Assiut, Egypt
| | - Azza Shibl
- Pediatric Oncology Department, South Egypt Cancer Institute, Assiut University, Assiut, Egypt
| | - Lamiaa Fadel
- Cancer Biology Department, South Egypt Cancer Institute, Assiut University, Assiut, Egypt
| | - Zeinab Korany Hassan
- Virology and Immunology Unit, Cancer Biology Department, National Cancer Institute, Cairo University, Cairo, Egypt
| | - Eman Hassan Ahmed
- Clinical Pathology Department, South Egypt Cancer Institute, Assiut University, Assiut, Egypt
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Dubowsky M, Theunissen F, Carr JM, Rogers ML. The Molecular Link Between TDP-43, Endogenous Retroviruses and Inflammatory Neurodegeneration in Amyotrophic Lateral Sclerosis: a Potential Target for Triumeq, an Antiretroviral Therapy. Mol Neurobiol 2023; 60:6330-6345. [PMID: 37450244 PMCID: PMC10533598 DOI: 10.1007/s12035-023-03472-y] [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: 04/12/2023] [Accepted: 06/30/2023] [Indexed: 07/18/2023]
Abstract
Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND), is a progressive neurological disorder, characterised by the death of upper and lower motor neurons. The aetiology of ALS remains unknown, and treatment options are limited. Endogenous retroviruses (ERVs), specifically human endogenous retrovirus type K (HERV-K), have been proposed to be involved in the propagation of neurodegeneration in ALS. ERVs are genomic remnants of ancient viral infection events, with most being inactive and not retaining the capacity to encode a fully infectious virus. However, some ERVs retain the ability to be activated and transcribed, and ERV transcripts have been found to be elevated within the brain tissue of MND patients. A hallmark of ALS pathology is altered localisation of the transactive response (TAR) DNA binding protein 43 kDa (TDP-43), which is normally found within the nucleus of neuronal and glial cells and is involved in RNA regulation. In ALS, TDP-43 aggregates within the cytoplasm and facilitates neurodegeneration. The involvement of ERVs in ALS pathology is thought to occur through TDP-43 and neuroinflammatory mediators. In this review, the proposed involvement of TDP-43, HERV-K and immune regulators on the onset and progression of ALS will be discussed. Furthermore, the evidence supporting a therapy based on targeting ERVs in ALS will be reviewed.
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Affiliation(s)
- Megan Dubowsky
- College of Medicine and Public Health and Flinders Health and Medical Research Institute, Flinders University, Bedford Park, SA, Australia.
| | - Frances Theunissen
- Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Murdoch, WA, Australia
| | - Jillian M Carr
- College of Medicine and Public Health and Flinders Health and Medical Research Institute, Flinders University, Bedford Park, SA, Australia
| | - Mary-Louise Rogers
- College of Medicine and Public Health and Flinders Health and Medical Research Institute, Flinders University, Bedford Park, SA, Australia
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Costa B, Vale N. Exploring HERV-K (HML-2) Influence in Cancer and Prospects for Therapeutic Interventions. Int J Mol Sci 2023; 24:14631. [PMID: 37834078 PMCID: PMC10572383 DOI: 10.3390/ijms241914631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/19/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023] Open
Abstract
This review investigates the intricate role of human endogenous retroviruses (HERVs) in cancer development and progression, explicitly focusing on HERV-K (HML-2). This paper sheds light on the latest research advancements and potential treatment strategies by examining the historical context of HERVs and their involvement in critical biological processes such as embryonic development, immune response, and disease progression. This review covers computational modeling for drug-target binding assessment, systems biology modeling for simulating HERV-K viral cargo dynamics, and using antiviral drugs to combat HERV-induced diseases. The findings presented in this review contribute to our understanding of HERV-mediated disease mechanisms and provide insights into future therapeutic approaches. They emphasize why HERV-K holds significant promise as a biomarker and a target.
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Affiliation(s)
- Bárbara Costa
- OncoPharma Research Group, Center for Health Technology and Services Research (CINTESIS), Rua Doutor Plácido da Costa, s/n, 4200-450 Porto, Portugal;
- CINTESIS@RISE, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
- Department of Community Medicine, Information and Health Decision Sciences (MEDCIDS), Faculty of Medicine, University of Porto, Rua Doutor Plácido da Costa, s/n, 4200-450 Porto, Portugal
| | - Nuno Vale
- OncoPharma Research Group, Center for Health Technology and Services Research (CINTESIS), Rua Doutor Plácido da Costa, s/n, 4200-450 Porto, Portugal;
- CINTESIS@RISE, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
- Department of Community Medicine, Information and Health Decision Sciences (MEDCIDS), Faculty of Medicine, University of Porto, Rua Doutor Plácido da Costa, s/n, 4200-450 Porto, Portugal
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Shah AH, Rivas SR, Doucet-O’Hare TT, Govindarajan V, DeMarino C, Wang T, Ampie L, Zhang Y, Banasavadi-Siddegowda YK, Walbridge S, Maric D, Garcia-Montojo M, Suter RK, Lee MH, Zaghloul KA, Steiner J, Elkahloun AG, Chandar J, Seetharam D, Desgraves J, Li W, Johnson K, Ivan ME, Komotar RJ, Gilbert MR, Heiss JD, Nath A. Human endogenous retrovirus K contributes to a stem cell niche in glioblastoma. J Clin Invest 2023; 133:e167929. [PMID: 37395282 PMCID: PMC10313366 DOI: 10.1172/jci167929] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 05/19/2023] [Indexed: 07/04/2023] Open
Abstract
Human endogenous retroviruses (HERVs) are ancestral viral relics that constitute nearly 8% of the human genome. Although normally silenced, the most recently integrated provirus HERV-K (HML-2) can be reactivated in certain cancers. Here, we report pathological expression of HML-2 in malignant gliomas in both cerebrospinal fluid and tumor tissue that was associated with a cancer stem cell phenotype and poor outcomes. Using single-cell RNA-Seq, we identified glioblastoma cellular populations with elevated HML-2 transcripts in neural progenitor-like cells (NPC-like) that drive cellular plasticity. Using CRISPR interference, we demonstrate that HML-2 critically maintained glioblastoma stemness and tumorigenesis in both glioblastoma neurospheres and intracranial orthotopic murine models. Additionally, we demonstrate that HML-2 critically regulated embryonic stem cell programs in NPC-derived astroglia and altered their 3D cellular morphology by activating the nuclear transcription factor OCT4, which binds to an HML-2-specific long-terminal repeat (LTR5Hs). Moreover, we discovered that some glioblastoma cells formed immature retroviral virions, and inhibiting HML-2 expression with antiretroviral drugs reduced reverse transcriptase activity in the extracellular compartment, tumor viability, and pluripotency. Our results suggest that HML-2 fundamentally contributes to the glioblastoma stem cell niche. Because persistence of glioblastoma stem cells is considered responsible for treatment resistance and recurrence, HML-2 may serve as a unique therapeutic target.
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Affiliation(s)
- Ashish H. Shah
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Sarah R. Rivas
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Tara T. Doucet-O’Hare
- Neuro-Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Vaidya Govindarajan
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Catherine DeMarino
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Tongguang Wang
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Leonel Ampie
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Yong Zhang
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | | | - Stuart Walbridge
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Dragan Maric
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Marta Garcia-Montojo
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Robert K. Suter
- Georgetown University, Bioinformatics Section, Washington, DC, USA
| | - Myoung-Hwa Lee
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Kareem A. Zaghloul
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Joseph Steiner
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Abdel G. Elkahloun
- Cancer Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, Maryland, USA
| | - Jay Chandar
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Deepa Seetharam
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Jelisah Desgraves
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Wenxue Li
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Kory Johnson
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Michael E. Ivan
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Ricardo J. Komotar
- University of Miami School of Medicine, Department of Neurosurgery, Miami, Florida, USA
| | - Mark R. Gilbert
- Neuro-Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - John D. Heiss
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
| | - Avindra Nath
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
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Hosseiniporgham S, Sechi LA. Anti-HERV-K Drugs and Vaccines, Possible Therapies against Tumors. Vaccines (Basel) 2023; 11:vaccines11040751. [PMID: 37112663 PMCID: PMC10144246 DOI: 10.3390/vaccines11040751] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 03/31/2023] Open
Abstract
The footprint of human endogenous retroviruses (HERV), specifically HERV-K, has been found in malignancies, such as melanoma, teratocarcinoma, osteosarcoma, breast cancer, lymphoma, and ovary and prostate cancers. HERV-K is characterized as the most biologically active HERV due to possession of open reading frames (ORF) for all Gag, Pol, and Env genes, which enables it to be more infective and obstructive towards specific cell lines and other exogenous viruses, respectively. Some factors might contribute to carcinogenicity and at least one of them has been recognized in various tumors, including overexpression/methylation of long interspersed nuclear element 1 (LINE-1), HERV-K Gag, and Env genes themselves plus their transcripts and protein products, and HERV-K reverse transcriptase (RT). Therapies effective for HERV-K-associated tumors mostly target invasive autoimmune responses or growth of tumors through suppression of HERV-K Gag or Env protein and RT. To design new therapeutic options, more studies are needed to better understand whether HERV-K and its products (Gag/Env transcripts and HERV-K proteins/RT) are the initiators of tumor formation or just the disorder’s developers. Accordingly, this review aims to present evidence that highlights the association between HERV-K and tumorigenicity and introduces some of the available or potential therapies against HERV-K-induced tumors.
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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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10
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Agoni L. Alternative and aberrant splicing of human endogenous retroviruses in cancer. What about head and neck? —A mini review. Front Oncol 2022; 12:1019085. [PMID: 36338752 PMCID: PMC9631305 DOI: 10.3389/fonc.2022.1019085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 10/03/2022] [Indexed: 11/13/2022] Open
Abstract
Human endogenous retroviruses (HERVs) are transcribed in many cancer types, including head and neck cancer. Because of accumulating mutations at proviral loci over evolutionary time, HERVs are functionally defective and cannot complete their viral life cycle. Despite that, HERV transcripts, including full-length viral RNAs and viral RNAs spliced as expected at the conventional viral splice sites, can be detected in particular conditions, such as cancer. Interestingly, non-viral–related transcription, including aberrant, non-conventionally spliced RNAs, has been reported as well. The role of HERV transcription in cancer and its contribution to oncogenesis or progression are still debated. Nonetheless, HERVs may constitute a suitable cancer biomarker or a target for therapy. Thus, ongoing research aims both to clarify the basic mechanisms underlying HERV transcription in cancer and to exploit its potential toward clinical application. In this mini-review, we summarize the current knowledge, the most recent findings, and the future perspectives of research on HERV transcription and splicing, with particular focus on head and neck cancer.
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11
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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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12
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Zhang M, Zheng S, Liang JQ. Transcriptional and reverse transcriptional regulation of host genes by human endogenous retroviruses in cancers. Front Microbiol 2022; 13:946296. [PMID: 35928153 PMCID: PMC9343867 DOI: 10.3389/fmicb.2022.946296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/29/2022] [Indexed: 11/16/2022] Open
Abstract
Human endogenous retroviruses (HERVs) originated from ancient retroviral infections of germline cells millions of years ago and have evolved as part of the host genome. HERVs not only retain the capacity as retroelements but also regulate host genes. The expansion of HERVs involves transcription by RNA polymerase II, reverse transcription, and re-integration into the host genome. Fast progress in deep sequencing and functional analysis has revealed the importance of domesticated copies of HERVs, including their regulatory sequences, transcripts, and proteins in normal cells. However, evidence also suggests the involvement of HERVs in the development and progression of many types of cancer. Here we summarize the current state of knowledge about the expression of HERVs, transcriptional regulation of host genes by HERVs, and the functions of HERVs in reverse transcription and gene editing with their reverse transcriptase.
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Affiliation(s)
- Mengwen Zhang
- The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
- Ministry of Education Key Laboratory of Cancer Prevention and Intervention, Second Affiliated Hospital, Cancer Institute, Zhejiang University School of Medicine, Hangzhou, China
| | - Shu Zheng
- The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
- Ministry of Education Key Laboratory of Cancer Prevention and Intervention, Second Affiliated Hospital, Cancer Institute, Zhejiang University School of Medicine, Hangzhou, China
- *Correspondence: Shu Zheng,
| | - Jessie Qiaoyi Liang
- Department of Medicine and Therapeutics, Faculty of Medicine, Center for Gut Microbiota Research, Li Ka Shing Institute of Health Sciences, Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong, Hong Kong SAR, China
- Jessie Qiaoyi Liang,
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13
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Fayzullina D, Kharwar RK, Acharya A, Buzdin A, Borisov N, Timashev P, Ulasov I, Kapomba B. FNC: An Advanced Anticancer Therapeutic or Just an Underdog? Front Oncol 2022; 12:820647. [PMID: 35223502 PMCID: PMC8867032 DOI: 10.3389/fonc.2022.820647] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/13/2022] [Indexed: 12/14/2022] Open
Abstract
Azvudine (FNC) is a novel cytidine analogue that has both antiviral and anticancer activities. This minireview focuses on its underlying molecular mechanisms of suppressing viral life cycle and cancer cell growth and discusses applications of this nucleoside drug for advanced therapy of tumors and malignant blood diseases. FNC inhibits positive-stand RNA viruses, like HCV, EV, SARS-COV-2, HBV, and retroviruses, including HIV, by suppressing their RNA-dependent polymerase enzymes. It may also inhibit such enzyme (reverse transcriptase) in the human retrotransposons, including human endogenous retroviruses (HERVs). As the activation of retrotransposons can be the major factor of ongoing cancer genome instability and consequently higher aggressiveness of tumors, FNC has a potential to increase the efficacy of multiple anticancer therapies. Furthermore, FNC also showed other aspects of anticancer activity by inhibiting adhesion, migration, invasion, and proliferation of malignant cells. It was also reported to be involved in cell cycle arrest and apoptosis, thereby inhibiting the progression of cancer through different pathways. To the date, the grounds of FNC effects on cancer cells are not fully understood and hence additional studies are needed for better understanding molecular mechanisms of its anticancer activities to support its medical use in oncology.
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Affiliation(s)
- Daria Fayzullina
- World-Class Research Center “Digital Biodesign and Personalized Healthcare”, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Rajesh Kumar Kharwar
- Endocrine Research Lab, Department of Zoology, Kutir Post Graduate College, Chakkey, Jaunpur, India
| | - Arbind Acharya
- Tumor Immunology Lab, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Anton Buzdin
- World-Class Research Center “Digital Biodesign and Personalized Healthcare”, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Nicolas Borisov
- Department of Medical and Biological Physics, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Peter Timashev
- World-Class Research Center “Digital Biodesign and Personalized Healthcare”, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Ilya Ulasov
- World-Class Research Center “Digital Biodesign and Personalized Healthcare”, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Byron Kapomba
- Department of General Surgery, Parirenyatwa Group of Hospitals, Harare, Zimbabwe,*Correspondence: Byron Kapomba,
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14
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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; 23:1330. [PMID: 35163254 PMCID: PMC8836156 DOI: 10.3390/ijms23031330] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [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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15
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HERV-K and HERV-H Env Proteins Induce a Humoral Response in Prostate Cancer Patients. Pathogens 2022; 11:pathogens11010095. [PMID: 35056043 PMCID: PMC8778306 DOI: 10.3390/pathogens11010095] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/10/2022] [Accepted: 01/13/2022] [Indexed: 02/01/2023] Open
Abstract
A higher expression of human endogenous retroviruses (HERVs) has been associated with several malignancies, including prostate cancer, implying a possible use as a diagnostic or prognostic cancer biomarker. For this reason, we examined the humoral response against different epitopes obtained from the envelope protein of HERV-K (HERV-K env-su19–37, HERV-K env-su109–126), HERV-H (HERV-H env-su229–241, HERV-H env387–399) and HERV-W (HERV-W env-su93–108, HERV-W env-su248–262) in the plasma of patients affected by prostate cancer (PCa), and compared to that of benign prostate hyperplasia (BPH) and a borderline group of patients with atypical small acinar proliferation (ASAP) and prostate intraepithelial neoplasia (PIN) and healthy controls. A significant antibody response was observed against HERV-K env-su109–126 (p = 0.004) and HERV-H env-su229–241 (p < 0.0001) in PCa patients compared to HCs, BPH and borderline cohorts, whilst no significance difference was found in the antibodies against HERV-W env-su93–108 and HERV-W env-su248–262 in patients with PCa. Our results provided further proof of the association between HERV-K and PCa and added new evidence about the possible involvement of HERV-H in PCa pathogenesis, highlighting their possibility of being used as biomarkers of the disease.
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16
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Durnaoglu S, Lee SK, Ahnn J. Human Endogenous Retroviruses as Gene Expression Regulators: Insights from Animal Models into Human Diseases. Mol Cells 2021; 44:861-878. [PMID: 34963103 PMCID: PMC8718366 DOI: 10.14348/molcells.2021.5016] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 11/27/2022] Open
Abstract
The human genome contains many retroviral elements called human endogenous retroviruses (HERVs), resulting from the integration of retroviruses throughout evolution. HERVs once were considered inactive junk because they are not replication-competent, primarily localized in the heterochromatin, and silenced by methylation. But HERVs are now clearly shown to actively regulate gene expression in various physiological and pathological conditions such as developmental processes, immune regulation, cancers, autoimmune diseases, and neurological disorders. Recent studies report that HERVs are activated in patients suffering from coronavirus disease 2019 (COVID-19), the current pandemic caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection. In this review, we describe internal and external factors that influence HERV activities. We also present evidence showing the gene regulatory activity of HERV LTRs (long terminal repeats) in model organisms such as mice, rats, zebrafish, and invertebrate models of worms and flies. Finally, we discuss several molecular and cellular pathways involving various transcription factors and receptors, through which HERVs affect downstream cellular and physiological events such as epigenetic modifications, calcium influx, protein phosphorylation, and cytokine release. Understanding how HERVs participate in various physiological and pathological processes will help develop a strategy to generate effective therapeutic approaches targeting HERVs.
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Affiliation(s)
- Serpen Durnaoglu
- Department of Life Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
- Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Sun-Kyung Lee
- Department of Life Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
- Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Joohong Ahnn
- Department of Life Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
- Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
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17
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Rodríguez-Frías F, Quer J, Tabernero D, Cortese MF, Garcia-Garcia S, Rando-Segura A, Pumarola T. Microorganisms as Shapers of Human Civilization, from Pandemics to Even Our Genomes: Villains or Friends? A Historical Approach. Microorganisms 2021; 9:2518. [PMID: 34946123 PMCID: PMC8708650 DOI: 10.3390/microorganisms9122518] [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: 10/25/2021] [Revised: 11/23/2021] [Accepted: 11/30/2021] [Indexed: 02/07/2023] Open
Abstract
Universal history is characterized by continuous evolution, in which civilizations are born and die. This evolution is associated with multiple factors, among which the role of microorganisms is often overlooked. Viruses and bacteria have written or decisively contributed to terrible episodes of history, such as the Black Death in 14th century Europe, the annihilation of pre-Columbian American civilizations, and pandemics such as the 1918 Spanish flu or the current COVID-19 pandemic caused by the coronavirus SARS-CoV-2. Nevertheless, it is clear that we could not live in a world without these tiny beings. Endogenous retroviruses have been key to our evolution and for the regulation of gene expression, and the gut microbiota helps us digest compounds that we could not otherwise process. In addition, we have used microorganisms to preserve or prepare food for millennia and more recently to obtain drugs such as antibiotics or to develop recombinant DNA technologies. Due to the enormous importance of microorganisms for our survival, they have significantly influenced the population genetics of different human groups. This paper will review the role of microorganisms as "villains" who have been responsible for tremendous mortality throughout history but also as "friends" who help us survive and evolve.
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Affiliation(s)
- Francisco Rodríguez-Frías
- Clinical Biochemistry Research Group, Department of Biochemistry, Vall d’Hebron Institut Recerca-Hospital Universitari Vall d’Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (M.F.C.); (S.G.-G.)
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, 28029 Madrid, Spain;
- Liver Pathology Unit, Departments of Biochemistry and Microbiology, Hospital Universitari Vall d’Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain;
| | - Josep Quer
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, 28029 Madrid, Spain;
- Liver Unit, Liver Disease Laboratory-Viral Hepatitis, Vall d’Hebron Institut Recerca, Hospital Universitari Vall d’Hebron, Vall d’Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain
| | - David Tabernero
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, 28029 Madrid, Spain;
| | - Maria Francesca Cortese
- Clinical Biochemistry Research Group, Department of Biochemistry, Vall d’Hebron Institut Recerca-Hospital Universitari Vall d’Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (M.F.C.); (S.G.-G.)
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, 28029 Madrid, Spain;
| | - Selene Garcia-Garcia
- Clinical Biochemistry Research Group, Department of Biochemistry, Vall d’Hebron Institut Recerca-Hospital Universitari Vall d’Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; (M.F.C.); (S.G.-G.)
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, 28029 Madrid, Spain;
| | - Ariadna Rando-Segura
- Liver Pathology Unit, Departments of Biochemistry and Microbiology, Hospital Universitari Vall d’Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain;
- Department of Microbiology, Hospital Universitari Vall d’Hebron, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain;
| | - Tomas Pumarola
- Department of Microbiology, Hospital Universitari Vall d’Hebron, Vall d’Hebron Barcelona Hospital Campus, Passeig Vall d’Hebron 119-129, 08035 Barcelona, Spain;
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18
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Kitsou K, Iliopoulou M, Spoulou V, Lagiou P, Magiorkinis G. Viral Causality of Human Cancer and Potential Roles of Human Endogenous Retroviruses in the Multi-Omics Era: An Evolutionary Epidemiology Review. Front Oncol 2021; 11:687631. [PMID: 34778024 PMCID: PMC8586426 DOI: 10.3389/fonc.2021.687631] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 10/12/2021] [Indexed: 12/20/2022] Open
Abstract
Being responsible for almost 12% of cancers worldwide, viruses are among the oldest known and most prevalent oncogenic agents. The quality of the evidence for the in vivo tumorigenic potential of microorganisms varies, thus accordingly, viruses were classified in 4 evidence-based categories by the International Agency for Research on Cancer in 2009. Since then, our understanding of the role of viruses in cancer has significantly improved, firstly due to the emergence of high throughput sequencing technologies that allowed the “brute-force” recovery of unknown viral genomes. At the same time, multi-omics approaches unravelled novel virus-host interactions in stem-cell biology. We now know that viral elements, either exogenous or endogenous, have multiple sometimes conflicting roles in human pathophysiology and the development of cancer. Here we integrate emerging evidence on viral causality in human cancer from basic mechanisms to clinical studies. We analyze viral tumorigenesis under the scope of deep-in-time human-virus evolutionary relationships and critically comment on the evidence through the eyes of clinical epidemiology, firstly by reviewing recognized oncoviruses and their mechanisms of inducing tumorigenesis, and then by examining the potential role of integrated viruses in our genome in the process of carcinogenesis.
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Affiliation(s)
- Konstantina Kitsou
- Department of Hygiene, Epidemiology and Medical Statistics, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece.,Immunobiology and Vaccinology Research Laboratory, First Department of Peadiatrics, "Aghia Sophia" Children's Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Maria Iliopoulou
- Department of Hygiene, Epidemiology and Medical Statistics, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Vana Spoulou
- Immunobiology and Vaccinology Research Laboratory, First Department of Peadiatrics, "Aghia Sophia" Children's Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Pagona Lagiou
- Department of Hygiene, Epidemiology and Medical Statistics, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Gkikas Magiorkinis
- Department of Hygiene, Epidemiology and Medical Statistics, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
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19
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Mao J, Zhang Q, Cong YS. Human endogenous retroviruses in development and disease. Comput Struct Biotechnol J 2021; 19:5978-5986. [PMID: 34849202 PMCID: PMC8604659 DOI: 10.1016/j.csbj.2021.10.037] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 12/16/2022] Open
Abstract
Human endogenous retroviruses (HERVs) represent ∼8% of human genome, deriving from exogenous retroviral infections of germ line cells occurred millions of years ago and being inherited by the offspring in a Mendelian fashion. Most of HERVs are nonprotein-coding because of the accumulation of mutations, insertions, deletions, and/or truncations. It has been long thought that HERVs were "junk DNA". However, it is now known that HERVs are involved in various biological processes through encoding proteins, acting as promoters/enhancers, or lncRNAs to affect human health and disease. In this review, we summarized recent findings about HERVs, with implications in embryonic development, pluripotency, cancer, aging, and neurodegenerative diseases.
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Affiliation(s)
- Jian Mao
- Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Hangzhou Normal University School of Basic Medical Sciences, Hangzhou, China
| | - Qian Zhang
- Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Hangzhou Normal University School of Basic Medical Sciences, Hangzhou, China
| | - Yu-Sheng Cong
- Key Laboratory of Aging and Cancer Biology of Zhejiang Province, Hangzhou Normal University School of Basic Medical Sciences, Hangzhou, China
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20
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Dervan E, Bhattacharyya DD, McAuliffe JD, Khan FH, Glynn SA. Ancient Adversary - HERV-K (HML-2) in Cancer. Front Oncol 2021; 11:658489. [PMID: 34055625 PMCID: PMC8155577 DOI: 10.3389/fonc.2021.658489] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/23/2021] [Indexed: 12/11/2022] Open
Abstract
Human endogenous retroviruses (HERV), ancient integrations of exogenous viruses, make up 8% of our genome. Long thought of as mere vestigial genetic elements, evidence is now accumulating to suggest a potential functional role in numerous pathologies including neurodegenerative diseases, autoimmune disorders, and multiple cancers. The youngest member of this group of transposable elements is HERV-K (HML-2). Like the majority of HERV sequences, significant post-insertional mutations have disarmed HERV-K (HML-2), preventing it from producing infectious viral particles. However, some insertions have retained limited coding capacity, and complete open reading frames for all its constituent proteins can be found throughout the genome. For this reason HERV-K (HML-2) has garnered more attention than its peers. The tight epigenetic control thought to suppress expression in healthy tissue is lost during carcinogenesis. Upregulation of HERV-K (HML-2) derived mRNA and protein has been reported in a variety of solid and liquid tumour types, and while causality has yet to be established, progressively more data are emerging to suggest this phenomenon may contribute to tumour growth and metastatic capacity. Herein we discuss its potential utility as a diagnostic tool and therapeutic target in light of the current in vitro, in vivo and clinical evidence linking HERV-K (HML-2) to tumour progression.
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Affiliation(s)
- Eoin Dervan
- Discipline of Pathology, Lambe Institute for Translational Research, School of Medicine, National University of Ireland Galway (NUIG), Galway, Ireland
| | - Dibyangana D Bhattacharyya
- Discipline of Pathology, Lambe Institute for Translational Research, School of Medicine, National University of Ireland Galway (NUIG), Galway, Ireland.,Laboratory of Cancer ImmunoMetabolism, National Cancer Institute, National Institutes of Health, Frederick, MD, United States
| | - Jake D McAuliffe
- Discipline of Pathology, Lambe Institute for Translational Research, School of Medicine, National University of Ireland Galway (NUIG), Galway, Ireland
| | - Faizan H Khan
- Discipline of Pathology, Lambe Institute for Translational Research, School of Medicine, National University of Ireland Galway (NUIG), Galway, Ireland
| | - Sharon A Glynn
- Discipline of Pathology, Lambe Institute for Translational Research, School of Medicine, National University of Ireland Galway (NUIG), Galway, Ireland
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21
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Padmanabhan Nair V, Liu H, Ciceri G, Jungverdorben J, Frishman G, Tchieu J, Cederquist GY, Rothenaigner I, Schorpp K, Klepper L, Walsh RM, Kim TW, Cornacchia D, Ruepp A, Mayer J, Hadian K, Frishman D, Studer L, Vincendeau M. Activation of HERV-K(HML-2) disrupts cortical patterning and neuronal differentiation by increasing NTRK3. Cell Stem Cell 2021; 28:1566-1581.e8. [PMID: 33951478 DOI: 10.1016/j.stem.2021.04.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 03/05/2021] [Accepted: 04/12/2021] [Indexed: 12/20/2022]
Abstract
The biological function and disease association of human endogenous retroviruses (HERVs) are largely elusive. HERV-K(HML-2) has been associated with neurotoxicity, but there is no clear understanding of its role or mechanistic basis. We addressed the physiological functions of HERV-K(HML-2) in neuronal differentiation using CRISPR engineering to activate or repress its expression levels in a human-pluripotent-stem-cell-based system. We found that elevated HERV-K(HML-2) transcription is detrimental for the development and function of cortical neurons. These effects are cell-type-specific, as dopaminergic neurons are unaffected. Moreover, high HERV-K(HML-2) transcription alters cortical layer formation in forebrain organoids. HERV-K(HML-2) transcriptional activation leads to hyperactivation of NTRK3 expression and other neurodegeneration-related genes. Direct activation of NTRK3 phenotypically resembles HERV-K(HML-2) induction, and reducing NTRK3 levels in context of HERV-K(HML-2) induction restores cortical neuron differentiation. Hence, these findings unravel a cell-type-specific role for HERV-K(HML-2) in cortical neuron development.
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Affiliation(s)
| | - Hengyuan Liu
- Department of Genome-Oriented Bioinformatics, Technical University Munich, Munich, Germany
| | - Gabriele Ciceri
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Johannes Jungverdorben
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Goar Frishman
- Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Jason Tchieu
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Gustav Y Cederquist
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ina Rothenaigner
- Assay Development and Screening Platform, Helmholtz Zentrum München, Neuherberg, Germany
| | - Kenji Schorpp
- Assay Development and Screening Platform, Helmholtz Zentrum München, Neuherberg, Germany
| | - Lena Klepper
- Institute of Virology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Ryan M Walsh
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Tae Wan Kim
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Daniela Cornacchia
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Andreas Ruepp
- Institute of Experimental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Jens Mayer
- Institute of Human Genetics, University of Saarland, Homburg, Germany
| | - Kamyar Hadian
- Assay Development and Screening Platform, Helmholtz Zentrum München, Neuherberg, Germany
| | - Dmitrij Frishman
- Department of Genome-Oriented Bioinformatics, Technical University Munich, Munich, Germany
| | - Lorenz Studer
- Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Michelle Vincendeau
- Institute of Virology, Helmholtz Zentrum München, Neuherberg, Germany; Developmental Biology and Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
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22
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Keegan RM, Talbot LR, Chang YH, Metzger MJ, Dubnau J. Intercellular viral spread and intracellular transposition of Drosophila gypsy. PLoS Genet 2021; 17:e1009535. [PMID: 33886543 PMCID: PMC8096092 DOI: 10.1371/journal.pgen.1009535] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 05/04/2021] [Accepted: 04/06/2021] [Indexed: 01/12/2023] Open
Abstract
It has become increasingly clear that retrotransposons (RTEs) are more widely expressed in somatic tissues than previously appreciated. RTE expression has been implicated in a myriad of biological processes ranging from normal development and aging, to age related diseases such as cancer and neurodegeneration. Long Terminal Repeat (LTR)-RTEs are evolutionary ancestors to, and share many features with, exogenous retroviruses. In fact, many organisms contain endogenous retroviruses (ERVs) derived from exogenous retroviruses that integrated into the germ line. These ERVs are inherited in Mendelian fashion like RTEs, and some retain the ability to transmit between cells like viruses, while others develop the ability to act as RTEs. The process of evolutionary transition between LTR-RTE and retroviruses is thought to involve multiple steps by which the element loses or gains the ability to transmit copies between cells versus the ability to replicate intracellularly. But, typically, these two modes of transmission are incompatible because they require assembly in different sub-cellular compartments. Like murine IAP/IAP-E elements, the gypsy family of retroelements in arthropods appear to sit along this evolutionary transition. Indeed, there is some evidence that gypsy may exhibit retroviral properties. Given that gypsy elements have been found to actively mobilize in neurons and glial cells during normal aging and in models of neurodegeneration, this raises the question of whether gypsy replication in somatic cells occurs via intracellular retrotransposition, intercellular viral spread, or some combination of the two. These modes of replication in somatic tissues would have quite different biological implications. Here, we demonstrate that Drosophila gypsy is capable of both cell-associated and cell-free viral transmission between cultured S2 cells of somatic origin. Further, we demonstrate that the ability of gypsy to move between cells is dependent upon a functional copy of its viral envelope protein. This argues that the gypsy element has transitioned from an RTE into a functional endogenous retrovirus with the acquisition of its envelope gene. On the other hand, we also find that intracellular retrotransposition of the same genomic copy of gypsy can occur in the absence of the Env protein. Thus, gypsy exhibits both intracellular retrotransposition and intercellular viral transmission as modes of replicating its genome.
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Affiliation(s)
- Richard M. Keegan
- Program in Neuroscience, Department of Neurobiology and Behavior, Stony Brook University, New York City, New York, United States of America
| | - Lillian R. Talbot
- Medical Scientist Training Program, Department of Neurobiology and Behavior, Stony Brook University, New York City, New York, United States of America
| | - Yung-Heng Chang
- Department of Anesthesiology, Stony Brook School of Medicine, New York City, New York, United States of America
| | - Michael J. Metzger
- Pacific Northwest Research Institute, Seattle, Washington, United States of America
| | - Josh Dubnau
- Program in Neuroscience, Department of Neurobiology and Behavior, Stony Brook University, New York City, New York, United States of America
- Department of Anesthesiology, Stony Brook School of Medicine, New York City, New York, United States of America
- Pacific Northwest Research Institute, Seattle, Washington, United States of America
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23
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Gao Y, Yu XF, Chen T. Human endogenous retroviruses in cancer: Expression, regulation and function. Oncol Lett 2020; 21:121. [PMID: 33552242 PMCID: PMC7798031 DOI: 10.3892/ol.2020.12382] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/27/2020] [Indexed: 12/16/2022] Open
Abstract
Human endogenous retroviruses (HERVs) are the remnants of ancient retroviruses that infected human germline cells and became integrated into the human genome millions of years ago. Although most of these sequences are incomplete and silent, several potential pathological roles of HERVs have been observed in numerous diseases, such as multiple sclerosis and rheumatoid arthritis, and especially cancer, including breast cancer and pancreatic carcinoma. The present review investigates the expression signatures and complex regulatory mechanisms of HERVs in cancer. The long terminal repeats-driven transcriptional initiation of HERVs are regulated by transcription factors (such as Sp3) and epigenetic modifications (such as DNA methylation), and are influenced by environmental factors (such as ultraviolet radiation). In addition, this review focuses on the dual opposing effects of HERVs in cancer. HERVs can suppress cancer via immune activation; however, they can also promote cancer. HERV env gene serves a prime role in promoting carcinogenesis in certain malignant tumors, including breast cancer, pancreatic cancer, germ cell tumors, leukemia and Kaposi's sarcoma. Also, HERV ENV proteins can promote cancer via immune suppression. Targeting ENV proteins is a potential future antitumor treatment modality.
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Affiliation(s)
- Yuan Gao
- Cancer Institute, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zheijang 310009, P.R. China
| | - Xiao-Fang Yu
- Cancer Institute, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zheijang 310009, P.R. China
| | - Ting Chen
- Cancer Institute, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zheijang 310009, P.R. China
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24
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Turelli P, Playfoot C, Grun D, Raclot C, Pontis J, Coudray A, Thorball C, Duc J, Pankevich EV, Deplancke B, Busskamp V, Trono D. Primate-restricted KRAB zinc finger proteins and target retrotransposons control gene expression in human neurons. SCIENCE ADVANCES 2020; 6:eaba3200. [PMID: 32923624 PMCID: PMC7455193 DOI: 10.1126/sciadv.aba3200] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 07/16/2020] [Indexed: 05/11/2023]
Abstract
In the first days of embryogenesis, transposable element-embedded regulatory sequences (TEeRS) are silenced by Kruppel-associated box (KRAB) zinc finger proteins (KZFPs). Many TEeRS are subsequently co-opted in transcription networks, but how KZFPs influence this process is largely unknown. We identify ZNF417 and ZNF587 as primate-specific KZFPs repressing HERVK (human endogenous retrovirus K) and SVA (SINE-VNTR-Alu) integrants in human embryonic stem cells (ESCs). Expressed in specific regions of the human developing and adult brain, ZNF417/587 keep controlling TEeRS in ESC-derived neurons and brain organoids, secondarily influencing the differentiation and neurotransmission profile of neurons and preventing the induction of neurotoxic retroviral proteins and an interferon-like response. Thus, evolutionarily recent KZFPs and their TE targets partner up to influence human neuronal differentiation and physiology.
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Affiliation(s)
- Priscilla Turelli
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Christopher Playfoot
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Dephine Grun
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Charlène Raclot
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Julien Pontis
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Alexandre Coudray
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Christian Thorball
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Julien Duc
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Eugenia V. Pankevich
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Bart Deplancke
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Volker Busskamp
- Center for Regenerative Therapies, Technische Universität Dresden, Dresden, Germany
- Faculty of Medicine, Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Didier Trono
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Corresponding author.
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25
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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: 57] [Impact Index Per Article: 14.3] [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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26
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Human Endogenous Retrovirus K in Cancer: A Potential Biomarker and Immunotherapeutic Target. Viruses 2020; 12:v12070726. [PMID: 32640516 PMCID: PMC7412025 DOI: 10.3390/v12070726] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/26/2020] [Accepted: 06/29/2020] [Indexed: 12/16/2022] Open
Abstract
In diseases where epigenetic mechanisms are changed, such as cancer, many genes show altered gene expression and inhibited genes become activated. Human endogenous retrovirus type K (HERV-K) expression is usually inhibited in normal cells from healthy adults. In tumor cells, however, HERV-K mRNA expression has been frequently documented to increase. Importantly, HERV-K-derived proteins can act as tumor-specific antigens, a class of neoantigens, and induce immune responses in different types of cancer. In this review, we describe the function of the HERV-K HML-2 subtype in carcinogenesis as biomarkers, and their potential as targets for cancer immunotherapy.
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