1
|
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.
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
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.
Collapse
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,
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Dolci M, Favero C, Toumi W, Favi E, Tarantini L, Signorini L, Basile G, Bollati V, D'Alessandro S, Bagnoli P, Ferrante P, Delbue S. Human Endogenous Retroviruses Long Terminal Repeat Methylation, Transcription, and Protein Expression in Human Colon Cancer. Front Oncol 2020; 10:569015. [PMID: 33194657 PMCID: PMC7653092 DOI: 10.3389/fonc.2020.569015] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 09/14/2020] [Indexed: 12/19/2022] Open
Abstract
Colon cancer is the fourth most common malignancy in both incidence and mortality in developed countries. Infectious agents are among the risk factors for colon cancer. Variations in human endogenous retrovirus (HERV) transcript and protein levels are associated with several types of cancers, but few studies address HERV expression in colon cancer. Fifty-eight patients with advanced-stage colon cancer were enrolled in this study. HERV-H, -K (HML-2), -P LTRs, Alu, and LINE-1 methylation levels and transcription of HERV-H, -K (HML-2), and -P env and HERV-K pol genes in normal adjacent and tumor tissues were investigated by pyrosequencing and RT-qPCR, respectively. Expression of the HERV-K (HML-2) Pol and Env proteins in selected tissues was examined by Western blotting. Associations between HERV transcript expression and methylation levels and between clinical characteristics and HERV expression were evaluated. Compared to adjacent normal tissues, LINE-1 was hypomethylated in tumor tissues (p < 0.05), whereas Alu, HERV-K (HML-2), and -H LTRs showed a decreasing trend in tumor tissue compared to normal tissue, though without a significant difference. The transcription levels of HERV env and pol genes were similar. However, the HERV-K (HML-2) Pol protein was more highly expressed (p < 0.01) in surrounding normal tissues, but the HERV-K (HML-2) Env protein was only expressed in tumor tissues. Although HERV LTR methylation and gene expression did not show significant differences between tumor and normal tissues, HERV protein expression differed greatly. Pol protein expression in normal cells may induce reverse transcription and subsequent integration into the host genome, likely favoring cell transformation; in contrast, the Env protein in tumor tissue may contribute to cancer progression through cell-to-cell fusion.
Collapse
Affiliation(s)
- Maria Dolci
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
| | - Chiara Favero
- EPIGET-Epidemiology, Epigenetics and Toxicology Lab, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Wafa Toumi
- Laboratory Services, Viral and Molecular Tumor Diagnostics Unit, Habib Thameur Hospital, Tunis, Tunisia
| | - Evaldo Favi
- Renal Transplantation, Fondazione Scientific Institute for Research, Hospitalization and Health Care Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy.,Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Letizia Tarantini
- EPIGET-Epidemiology, Epigenetics and Toxicology Lab, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Lucia Signorini
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
| | - Giuseppe Basile
- Orthopedic Department, San Siro Clinical Institute, Milan, Italy
| | - Valentina Bollati
- EPIGET-Epidemiology, Epigenetics and Toxicology Lab, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Sarah D'Alessandro
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
| | - Pietro Bagnoli
- Surgical Department, Istituto Clinico Città Studi, Milan, Italy
| | - Pasquale Ferrante
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
| | - Serena Delbue
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
| |
Collapse
|
6
|
Dolci M, Favero C, Tarantini L, Villani S, Bregni M, Signorini L, Della Valle A, Crivelli F, D'Alessandro S, Ferrante P, Bollati V, Delbue S. Human endogenous retroviruses env gene expression and long terminal repeat methylation in colorectal cancer patients. Med Microbiol Immunol 2020; 209:189-199. [PMID: 32040616 DOI: 10.1007/s00430-020-00662-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 01/30/2020] [Indexed: 02/07/2023]
Abstract
Human endogenous retroviruses (HERV) are remnants of exogenous retroviral infections, representing 8% of the human genome. Their regulation is based on the DNA methylation of promoters, the long terminal repeats (LTRs). Transcripts from HERV have been associated with cancers, but reports concerning HERV expression in colorectal cancer remain sporadic. Sixty-three patients with advanced stages of colorectal cancer were enrolled in this study. The expressions of HERV env gene, and HERV-H, -K, -R and -P LTRs and Alu, LINE-1 methylation levels, were investigated in the tumor, normal adjacent tissues, and, where possible, blood and plasmatic extracellular vesicles (EVs). Associations among HERV env expression, methylation status and clinical characteristics were evaluated. No differences were observed in HERV env gene expression levels among the clinical specimens, while Alu, LINE-1, HERV-H and -K LTRs were demethylated in the tumor compared to the normal adjacent tissues (p < 0.05).The HERV env gene was expressed in the EVs at of 54% (-H), 38% (-K), 31% (-R) patients. Association was not found between HERV env expression and LTR methylation, but significant higher expression of HERV-P and -R env was found in tumor tissues arising from the right colon. Our findings do not demonstrate significant overexpression of the studied HERV in colorectal cancer, but their association with tumor localization and specificity of the changes in DNA methylation of retroelements are shown. HERV sequences were packaged in the EVs and might be transferred from one cell to another.
Collapse
Affiliation(s)
- Maria Dolci
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Via Carlo Pascal, 36, 20133, Milan, Italy
| | - Chiara Favero
- EPIGET - Epidemiology, Epigenetics and Toxicology Lab, Department of Clinical Sciences and Community Health, University of Milan, Via San Barnaba 8, Milan, Italy
| | - Letizia Tarantini
- Department of Preventive Medicine, Fondazione IRCSS Ca' Granda, Ospedale Maggiore Policlinico, Via San Barnaba 8, Milan, Italy
| | - Sonia Villani
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Via Carlo Pascal, 36, 20133, Milan, Italy
| | - Marco Bregni
- Hematology Unit, ASST Valle Olona, Ospedale di Circolo di Busto Arsizio, Via Arnaldo da Brescia 3, Busto Arsizio, Italy
| | - Lucia Signorini
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Via Carlo Pascal, 36, 20133, Milan, Italy
| | - Alberto Della Valle
- General Surgery Unit, Istituto Clinico Città Studi, Via Jommelli 19, Milan, Italy
| | - Filippo Crivelli
- Pathology Unit, ASST Valle Olona, Ospedale di Circolo di Busto Arsizio, Via Arnaldo da Brescia 3, Busto Arsizio, Italy
| | - Sarah D'Alessandro
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Via Carlo Pascal, 36, 20133, Milan, Italy
| | - Pasquale Ferrante
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Via Carlo Pascal, 36, 20133, Milan, Italy
| | - Valentina Bollati
- EPIGET - Epidemiology, Epigenetics and Toxicology Lab, Department of Clinical Sciences and Community Health, University of Milan, Via San Barnaba 8, Milan, Italy.,Department of Preventive Medicine, Fondazione IRCSS Ca' Granda, Ospedale Maggiore Policlinico, Via San Barnaba 8, Milan, Italy
| | - Serena Delbue
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Via Carlo Pascal, 36, 20133, Milan, Italy.
| |
Collapse
|
7
|
Zhang M, Liang JQ, Zheng S. Expressional activation and functional roles of human endogenous retroviruses in cancers. Rev Med Virol 2019; 29:e2025. [PMID: 30614117 PMCID: PMC6590502 DOI: 10.1002/rmv.2025] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 10/26/2018] [Accepted: 11/05/2018] [Indexed: 12/26/2022]
Abstract
Human endogenous retroviruses (HERVs) are widely believed to be remnants of ancestral germ line infections by exogenous retroviruses. Although HERVs are deemed as “nonfunctional DNAs” due to loss of most of their viral protein coding capacity during evolution as part of the human genome, cumulative evidences are showing the expressional activation and potential roles of HERVs in diseases especially cancers. Work by other researchers and us has observed the dysregulation of HERVs in cancers, identified new HERV‐related genes, and revealed their potential importance in cancer development. Here, we summarized the current knowledge on the mechanisms of the expressional activation and functional roles of HERVs, with a focus on the H family HERV (HERV‐H), in carcinogenesis. HERV expression is regulated by external chemical or physical substances and exogenous virus infection, as well as host factors such as epigenetic DNA methylation, transcription factors, cytokines, and small RNAs. Diverse roles of HERVs have been proposed by acting in the forms of noncoding RNAs, proteins, and transcriptional regulators during carcinogenesis. However, much remains to be learnt about the contributions of HERVs to human cancers. More investigation is warranted to elucidate the functions of these “fossil remnants” yet important viral DNAs in the human genome.
Collapse
Affiliation(s)
- Mengwen Zhang
- The Department of Plastic and Reconstructive Surgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Cancer Institute, Second Affiliated Hospital, and Ministry of Education Key Laboratory of Cancer Prevention and Intervention, Zhejiang University School of Medicine, Hangzhou, China
| | - Jessie Qiaoyi Liang
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong, China
| | - Shu Zheng
- Cancer Institute, Second Affiliated Hospital, and Ministry of Education Key Laboratory of Cancer Prevention and Intervention, Zhejiang University School of Medicine, Hangzhou, China.,The Department of surgical oncology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| |
Collapse
|
8
|
Pérot P, Mullins CS, Naville M, Bressan C, Hühns M, Gock M, Kühn F, Volff JN, Trillet-Lenoir V, Linnebacher M, Mallet F. Expression of young HERV-H loci in the course of colorectal carcinoma and correlation with molecular subtypes. Oncotarget 2016; 6:40095-111. [PMID: 26517682 PMCID: PMC4741882 DOI: 10.18632/oncotarget.5539] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Accepted: 10/13/2015] [Indexed: 01/02/2023] Open
Abstract
Background Expression of the human endogenous retrovirus (HERV)-H family has been associated with colorectal carcinomas (CRC), yet no individual HERV-H locus expression has been thoroughly correlated with clinical data. Here, we characterized HERV-H reactivations in clinical CRC samples by integrating expression profiles, molecular patterns and clinical data. Expression of relevant HERV-H sequences was analyzed by qRT-PCR on two well-defined clinical cohorts (n = 139 pairs of tumor and adjacent normal colon tissue) including samples from adenomas (n = 21) and liver metastases (n = 16). Correlations with clinical and molecular data were assessed. Results CRC specific HERV-H sequences were validated and found expressed throughout CRC disease progression. Correlations between HERV-H expression and lymph node invasion of tumor cells (p = 0.0006) as well as microsatellite instable tumors (p < 0.0001) were established. No association with regard to age, tumor localization, grading or common mutations became apparent. Interestingly, CRC expressed elements belonged to specific young HERV-H subfamilies and their 5′ LTR often presented active histone marks. Conclusion These results suggest a functional role of HERV-H sequences in colorectal carcinogenesis. The pronounced connection with microsatellite instability warrants a more detailed investigation. Thus, HERV-H sequences in addition to tumor specific mutations may represent clinically relevant, truly CRC specific markers for diagnostic, prognostic and therapeutic purposes.
Collapse
Affiliation(s)
- Philippe Pérot
- Cancer Biomarkers Research Group, Joint Unit Hospices Civils de Lyon, bioMérieux, Centre Hospitalier Lyon Sud, Pierre Bénite, France.,Current address: Institut Pasteur, Laboratory for Pathogen Discovery, Paris, France
| | - Christina Susanne Mullins
- Cancer Biomarkers Research Group, Joint Unit Hospices Civils de Lyon, bioMérieux, Centre Hospitalier Lyon Sud, Pierre Bénite, France.,Centre d'Investigation des Thérapeutiques en Oncologie et Hématologie, EMR 3738 Lyon Claude Bernard University, Institut de Cancérologie des Hospices Civils de Lyon, Lyon, France
| | - Magali Naville
- Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure de Lyon, CNRS/Université Lyon I, Lyon, France
| | - Cédric Bressan
- Cancer Biomarkers Research Group, Joint Unit Hospices Civils de Lyon, bioMérieux, Centre Hospitalier Lyon Sud, Pierre Bénite, France
| | - Maja Hühns
- Institute of Pathology, University Medicine Rostock, Rostock, Germany
| | - Michael Gock
- Department of General, Thoracic, Vascular and Transplantation Surgery, University Medicine Rostock, Rostock, Germany
| | - Florian Kühn
- Department of General, Thoracic, Vascular and Transplantation Surgery, University Medicine Rostock, Rostock, Germany
| | - Jean-Nicolas Volff
- Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure de Lyon, CNRS/Université Lyon I, Lyon, France
| | - Véronique Trillet-Lenoir
- Centre d'Investigation des Thérapeutiques en Oncologie et Hématologie, EMR 3738 Lyon Claude Bernard University, Institut de Cancérologie des Hospices Civils de Lyon, Lyon, France
| | - Michael Linnebacher
- Department of General Surgery, Molecular Oncology and Immunotherapy, University Medicine Rostock, Rostock, Germany
| | - François Mallet
- Cancer Biomarkers Research Group, Joint Unit Hospices Civils de Lyon, bioMérieux, Centre Hospitalier Lyon Sud, Pierre Bénite, France
| |
Collapse
|
9
|
Mullins CS, Hühns M, Krohn M, Peters S, Cheynet V, Oriol G, Guillotte M, Ducrot S, Mallet F, Linnebacher M. Generation, Characterization and Application of Antibodies Directed against HERV-H Gag Protein in Colorectal Samples. PLoS One 2016; 11:e0153349. [PMID: 27119520 PMCID: PMC4847760 DOI: 10.1371/journal.pone.0153349] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 03/28/2016] [Indexed: 01/01/2023] Open
Abstract
Introduction A substantial part of the human genome originates from transposable elements, remnants of ancient retroviral infections. Roughly 8% of the human genome consists of about 400,000 LTR elements including human endogenous retrovirus (HERV) sequences. Mainly, the interplay between epigenetic and post-transcriptional mechanisms is thought to silence HERV expression in most physiological contexts. Interestingly, aberrant reactivation of several HERV-H loci appears specific to colorectal carcinoma (CRC). Results The expression of HERV-H Gag proteins (Gag-H) was assessed using novel monoclonal mouse anti Gag-H antibodies. In a flow cytometry screen four antibody clones were tested on a panel of primary CRC cell lines and the most well performing ones were subsequently validated in western blot analysis. Finally, Gag-H protein expression was analyzed by immune histology on cell line cytospins and on clinical samples. There, we found a heterogeneous staining pattern with no background staining of endothelial, stromal and infiltrating immune cells but diffuse staining of the cytoplasm for positive tumor and normal crypt cells of the colonic epithelium. Conclusion Taken together, the Gag-H antibody clone(s) present a valuable tool for staining of cells with colonic origin and thus form the basis for future more detailed investigations. The observed Gag-H protein staining in colonic epithelium crypt cells demands profound analyses of a potential role for Gag-H in the normal physiology of the human gut.
Collapse
Affiliation(s)
- Christina S. Mullins
- University Medicine Rostock, Department of General Surgery, Molecular Oncology and Immunotherapy, Schillingallee 69, 18057 Rostock, Germany
| | - Maja Hühns
- University Medicine Rostock, Institute of Pathology, Strempelstraße 14, 18055 Rostock, Germany
| | - Mathias Krohn
- University Medicine Rostock, Department of General Surgery, Molecular Oncology and Immunotherapy, Schillingallee 69, 18057 Rostock, Germany
| | - Sven Peters
- University Medicine Rostock, Department of General Surgery, Molecular Oncology and Immunotherapy, Schillingallee 69, 18057 Rostock, Germany
| | - Valérie Cheynet
- Joint Unit Hospices Civils de Lyon, bioMérieux, Cancer Biomarkers Research Group, Centre Hospitalier Lyon Sud, Bâtiment 3F, 69495, Pierre Bénite cedex, Lyon, France
| | - Guy Oriol
- Joint Unit Hospices Civils de Lyon, bioMérieux, Cancer Biomarkers Research Group, Centre Hospitalier Lyon Sud, Bâtiment 3F, 69495, Pierre Bénite cedex, Lyon, France
| | | | - Sandrine Ducrot
- R&D Immunoassay, bioMérieux, Raw Material Department, Marcy l’Etoile, France
| | - François Mallet
- Joint Unit Hospices Civils de Lyon, bioMérieux, Cancer Biomarkers Research Group, Centre Hospitalier Lyon Sud, Bâtiment 3F, 69495, Pierre Bénite cedex, Lyon, France
- EA Pathophysiology of injury-induced immunosuppression, University of Lyon1–Hospices Civils de Lyon–bioMérieux,Hôpital Edouard Herriot, 5, Place d’Arsonval, 69437 LYON Cedex 3, Lyon, France
| | - Michael Linnebacher
- University Medicine Rostock, Department of General Surgery, Molecular Oncology and Immunotherapy, Schillingallee 69, 18057 Rostock, Germany
- * E-mail:
| |
Collapse
|
10
|
Pérot P, Mugnier N, Montgiraud C, Gimenez J, Jaillard M, Bonnaud B, Mallet F. Microarray-based sketches of the HERV transcriptome landscape. PLoS One 2012; 7:e40194. [PMID: 22761958 PMCID: PMC3386233 DOI: 10.1371/journal.pone.0040194] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 06/02/2012] [Indexed: 12/15/2022] Open
Abstract
Human endogenous retroviruses (HERVs) are spread throughout the genome and their long terminal repeats (LTRs) constitute a wide collection of putative regulatory sequences. Phylogenetic similarities and the profusion of integration sites, two inherent characteristics of transposable elements, make it difficult to study individual locus expression in a large-scale approach, and historically apart from some placental and testis-regulated elements, it was generally accepted that HERVs are silent due to epigenetic control. Herein, we have introduced a generic method aiming to optimally characterize individual loci associated with 25-mer probes by minimizing cross-hybridization risks. We therefore set up a microarray dedicated to a collection of 5,573 HERVs that can reasonably be assigned to a unique genomic position. We obtained a first view of the HERV transcriptome by using a composite panel of 40 normal and 39 tumor samples. The experiment showed that almost one third of the HERV repertoire is indeed transcribed. The HERV transcriptome follows tropism rules, is sensitive to the state of differentiation and, unexpectedly, seems not to correlate with the age of the HERV families. The probeset definition within the U3 and U5 regions was used to assign a function to some LTRs (i.e. promoter or polyA) and revealed that (i) autonomous active LTRs are broadly subjected to operational determinism (ii) the cellular gene density is substantially higher in the surrounding environment of active LTRs compared to silent LTRs and (iii) the configuration of neighboring cellular genes differs between active and silent LTRs, showing an approximately 8 kb zone upstream of promoter LTRs characterized by a drastic reduction in sense cellular genes. These gathered observations are discussed in terms of virus/host adaptive strategies, and together with the methods and tools developed for this purpose, this work paves the way for further HERV transcriptome projects.
Collapse
Affiliation(s)
- Philippe Pérot
- Joint Unit Hospices Civils de Lyon, bioMérieux, Cancer Biomarkers Research Group, Centre Hospitalier Lyon Sud, Lyon, France
| | - Nathalie Mugnier
- BioMérieux, Data and Knowledge Laboratory, Marcy l’Etoile, France
| | - Cécile Montgiraud
- Joint Unit Hospices Civils de Lyon, bioMérieux, Cancer Biomarkers Research Group, Centre Hospitalier Lyon Sud, Lyon, France
| | - Juliette Gimenez
- Joint Unit Hospices Civils de Lyon, bioMérieux, Cancer Biomarkers Research Group, Centre Hospitalier Lyon Sud, Lyon, France
| | - Magali Jaillard
- BioMérieux, Data and Knowledge Laboratory, Marcy l’Etoile, France
| | - Bertrand Bonnaud
- BioMérieux, Data and Knowledge Laboratory, Marcy l’Etoile, France
| | - François Mallet
- Joint Unit Hospices Civils de Lyon, bioMérieux, Cancer Biomarkers Research Group, Centre Hospitalier Lyon Sud, Lyon, France
- * E-mail:
| |
Collapse
|
11
|
Expression patterns of non-coding spliced transcripts from human endogenous retrovirus HERV-H elements in colon cancer. PLoS One 2012; 7:e29950. [PMID: 22238681 PMCID: PMC3253121 DOI: 10.1371/journal.pone.0029950] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 12/07/2011] [Indexed: 11/25/2022] Open
Abstract
Background Up-regulation of the most abundant H family human endogenous retrovirus (HERV-H), especially env-related transcripts, correlates with colon cancer. However, expression pattern of spliced non-coding transcripts of HERV-H is not clear. Methodology/Principal Findings In this study, expression of HERV-H spliced transcripts in colon cancer was investigated by a RT-PCR strategy using primers targeting the tRNAHis primer-binding site and the R region in the 3′ long terminal repeat (LTR), followed by cloning and sequencing of the amplicons. Sequences were then assigned to individual HERV-H loci by employing private nucleotide differences between loci. Different expression patterns of HERV-H spliced transcripts from distinct active elements were found in colon cancer cell lines HT29, LS 174T, RKO, SW480 and SW620. Furthermore, the expression patterns in SW480 and RKO were significantly changed by demethylation treatment. Interestingly, more HERV-H elements were found to be transcriptionally active in colon tumor tissues than in adjacent normal tissues (14 vs. 7). Conclusions/Significance This is the first research to study the character of expression of non-coding spliced transcripts of HERV-H elements in colon cancer. Expression patterns of HERV-H spliced transcripts differed among colon cancer cell lines and could be affected by genomic DNA methylation levels. More importantly, besides the commonly accepted view of up-regulation of HERV-H expression in colon tumor tissues, we found more active HERV-H loci in colon tumor as compared with adjacent normal tissues.
Collapse
|
12
|
Kines KJ, Belancio VP. Expressing genes do not forget their LINEs: transposable elements and gene expression. FRONT BIOSCI-LANDMRK 2012; 17:1329-44. [PMID: 22201807 DOI: 10.2741/3990] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Historically the accumulated mass of mammalian transposable elements (TEs), particularly those located within gene boundaries, was viewed as a genetic burden potentially detrimental to the genomic landscape. This notion has been strengthened by the discovery that transposable sequences can alter the architecture of the transcriptome, not only through insertion, but also long after the integration process is completed. Insertions previously considered harmless are now known to impact the expression of host genes via modification of the transcript quality or quantity, transcriptional interference, or by the control of pathways that affect the mRNA life-cycle. Conversely, several examples of the evolutionary advantageous impact of TEs on the host gene structure that diversified the cellular transcriptome are reported. TE-induced changes in gene expression can be tissue- or disease-specific, raising the possibility that the impact of TE sequences may vary during development, among normal cell types, and between normal and disease-affected tissues. The understanding of the rules and abundance of TE-interference with gene expression is in its infancy, and its contribution to human disease and/or evolution remains largely unexplored.
Collapse
Affiliation(s)
- Kristine J Kines
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane University Cancer Center and Tulane Center for Aging
| | | |
Collapse
|
13
|
Liang Q, Ding J, Xu R, Xu Z, Zheng S. The novel human endogenous retrovirus-related gene, psiTPTE22-HERV, is silenced by DNA methylation in cancers. Int J Cancer 2010; 127:1833-43. [PMID: 20112338 DOI: 10.1002/ijc.25213] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The psiTPTE22 gene has been designated as a TPTE pseudogene. Our study found that the 5' part of psiTPTE22 has no sequence similarity to TPTE and contains a 3.8-kb human endogenous retrovirus (HERV) element. Because of the HERV element, the 5' part of psiTPTE22 (psiTPTE22-HERV) expresses independently as a gene. Comparison between the DNA sequences of humans and chimps indicated that psiTPTE22-HERV is human specific. We identified 3 alternatively spliced transcript variants from psiTPTE22-HERV by a PCR-based strategy, which use the transcriptional termination signal contained in the HERV element. A 402-nt ORF was contained in the 2 longer transcripts. Western blotting using antibodies produced with chemically synthesized peptide confirmed that a 15-kDa protein was translated from this ORF. RT-PCR results indicated that the ORF-containing transcripts were mainly expressed in psiTPTE22-HERV-expressing samples. Real-time quantitative RT-PCR results showed that expression of the 402-nt ORF was upregulated in normal tissues of kidney, liver, stomach, and lung but downregulated in corresponding tumor tissues. This gene is located near the centromere of chromosome 22 and has a high GC content around the promoter region. Bisulfite sequencing PCR results indicated that it is silenced in cancers by DNA methylation. The expression of psiTPTE22-HERV can be recovered in cancer cells using DNA methylation and histone deacetylase inhibitors. These results suggest psiTPTE22-HERV is regulated epigenetically by DNA methylation. Our study paved the way for further study on an interesting HERV-related human-specific gene, which is silenced in cancers by DNA methylation.
Collapse
Affiliation(s)
- Qiaoyi Liang
- Cancer Institute, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | | | | | | | | |
Collapse
|
14
|
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: 76] [Impact Index Per Article: 5.4] [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.
Collapse
Affiliation(s)
- M T Romanish
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada.
| | | | | |
Collapse
|