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Amere Subbarao S. Cancer vs. SARS-CoV-2 induced inflammation, overlapping functions, and pharmacological targeting. Inflammopharmacology 2021; 29:343-366. [PMID: 33723711 PMCID: PMC7959277 DOI: 10.1007/s10787-021-00796-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 02/27/2021] [Indexed: 12/15/2022]
Abstract
Inflammation is an intrinsic defence mechanism triggered by the immune system against infection or injury. Chronic inflammation allows the host to recover or adapt through cellular and humoral responses, whereas acute inflammation leads to cytokine storms resulting in tissue damage. In this review, we present the overlapping outcomes of cancer inflammation with virus-induced inflammation. The study emphasises how anti-inflammatory drugs that work against cancer inflammation may work against the inflammation caused by the viral infection. It is established that the cytokine storm induced in response to SARS-CoV-2 infection contributes to disease-associated mortality. While cancer remains the second among the diseases associated with mortality worldwide, cancer patients' mortality rates are often observed upon extended periods after illness, usually ranging from months to years. However, the mortality rates associated with COVID-19 disease are robust. The cytokine storm induced by SARS-CoV-2 infection appeared to be responsible for the multi-organ failure and increased mortality rates. Since both cancer and COVID-19 disease share overlapping inflammatory mechanisms, repurposing some anticancer and anti-inflammatory drugs for COVID-19 may lower mortality rates. Here, we review some of these inflammatory mechanisms and propose some potential chemotherapeutic agents to intervene in them. We also discuss the repercussions of anti-inflammatory drugs such as glucocorticoids and hydroxychloroquine with zinc or antiviral drugs such as ivermectin and remdesivir against SARS-CoV-2 induced cytokine storm. In this review, we emphasise on various possibilities to reduce SARS-CoV-2 induced cytokine storm.
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2
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He C, Lv X, Huang C, Angeletti PC, Hua G, Dong J, Zhou J, Wang Z, Ma B, Chen X, Lambert PF, Rueda BR, Davis JS, Wang C. A Human Papillomavirus-Independent Cervical Cancer Animal Model Reveals Unconventional Mechanisms of Cervical Carcinogenesis. Cell Rep 2020; 26:2636-2650.e5. [PMID: 30840887 PMCID: PMC6812687 DOI: 10.1016/j.celrep.2019.02.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 12/30/2018] [Accepted: 02/01/2019] [Indexed: 01/17/2023] Open
Abstract
HPV infections are common in healthy women and only rarely cause cervical cancer, suggesting that individual genetic susceptibility may play a critical role in the establishment of persistent HPV infection and the development of cervical cancer. Here, we provide convincing in vitro and in vivo evidence showing that differential expression and activation of YAP1 oncogene determine individual susceptibility to HPV infection and cervical carcinogenesis. We found that hyperactivation of YAP1 in mouse cervical epithelium was sufficient to induce invasive cervical cancer. Cervical epithelial cell-specific HPV16 E6/E7 and YAP1 double-knockin mouse model demonstrated that high-risk HPV synergized with hyperactivated YAP1 to promote the initiation and progression of cervical cancer. Our mechanistic studies indicated that hyperactivation of YAP1 in cervical epithelial cells facilitated HPV infection by increasing the putative HPV receptor molecules and disrupting host cell innate immunity. Our finding reveals an unconventional mechanism for cervical carcinogenesis. HPV infections are common in healthy women and only rarely cause cervical cancer. He et al. provide evidence that hyperactivation of the YAP1 oncogene can drive cervical cancer initiation and progression. YAP1 hyperactivation in cervical epithelial cells increases the HPV receptors and disrupts host cell innate immunity, facilitating HPV infection.
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Affiliation(s)
- Chunbo He
- Vincent Center for Reproductive Biology, Vincent Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA 02114, USA; Olson Center for Women's Health, Department of Obstetrics & Gynecology, University of Nebraska Medical Center, Omaha, NE 68198, USA; College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiangmin Lv
- Vincent Center for Reproductive Biology, Vincent Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA 02114, USA; Olson Center for Women's Health, Department of Obstetrics & Gynecology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Cong Huang
- Vincent Center for Reproductive Biology, Vincent Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Peter C Angeletti
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
| | - Guohua Hua
- Olson Center for Women's Health, Department of Obstetrics & Gynecology, University of Nebraska Medical Center, Omaha, NE 68198, USA; College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jixin Dong
- Fred & Pamela Cancer Center, University of Nebraska Medical Center, Omaha NE 68198, USA
| | - Jin Zhou
- Olson Center for Women's Health, Department of Obstetrics & Gynecology, University of Nebraska Medical Center, Omaha, NE 68198, USA; Department of Obstetrics and Gynecology, The Eighth Affiliated Hospital of Sun Yat-Sen University, Shenzhen, 518033, China
| | - Zhengfeng Wang
- Olson Center for Women's Health, Department of Obstetrics & Gynecology, University of Nebraska Medical Center, Omaha, NE 68198, USA; Department of Hepatobiliary Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 45001 China
| | - Bowen Ma
- Olson Center for Women's Health, Department of Obstetrics & Gynecology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Xingcheng Chen
- Fred & Pamela Cancer Center, University of Nebraska Medical Center, Omaha NE 68198, USA
| | - Paul F Lambert
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Bo R Rueda
- Vincent Center for Reproductive Biology, Vincent Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - John S Davis
- Olson Center for Women's Health, Department of Obstetrics & Gynecology, University of Nebraska Medical Center, Omaha, NE 68198, USA; Omaha Veterans Affairs Medical Center, Omaha, NE 68105, USA
| | - Cheng Wang
- Vincent Center for Reproductive Biology, Vincent Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA 02114, USA; Olson Center for Women's Health, Department of Obstetrics & Gynecology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
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Khan MS, Gupta AK, Kumar M. ViralEpi v1.0: a high-throughput spectrum of viral epigenomic methylation profiles from diverse diseases. Epigenomics 2015; 8:67-75. [PMID: 26678852 DOI: 10.2217/epi.15.95] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
AIMS To develop a computational resource for viral epigenomic methylation profiles from diverse diseases. MATERIALS & METHODS Methylation patterns of Epstein-Barr virus and hepatitis B virus genomic regions are provided as web platform developed using open source Linux-Apache-MySQL-PHP (LAMP) bundle: programming and scripting languages, that is, HTML, JavaScript and PERL. RESULTS A comprehensive and integrated web resource ViralEpi v1.0 is developed providing well-organized compendium of methylation events and statistical analysis associated with several diseases. Additionally, it also facilitates 'Viral EpiGenome Browser' for user-affable browsing experience using JavaScript-based JBrowse. CONCLUSION This web resource would be helpful for research community engaged in studying epigenetic biomarkers for appropriate prognosis and diagnosis of diseases and its various stages.
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Affiliation(s)
- Mohd Shoaib Khan
- Bioinformatics Centre, Institute of Microbial Technology, Council of Scientific & Industrial Research (CSIR), Sector 39-A, Chandigarh-160036, India
| | - Amit Kumar Gupta
- Bioinformatics Centre, Institute of Microbial Technology, Council of Scientific & Industrial Research (CSIR), Sector 39-A, Chandigarh-160036, India
| | - Manoj Kumar
- Bioinformatics Centre, Institute of Microbial Technology, Council of Scientific & Industrial Research (CSIR), Sector 39-A, Chandigarh-160036, India
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Monot M, Archer F, Gomes M, Mornex JF, Leroux C. Advances in the study of transmissible respiratory tumours in small ruminants. Vet Microbiol 2015; 181:170-7. [PMID: 26340900 DOI: 10.1016/j.vetmic.2015.08.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Sheep and goats are widely infected by oncogenic retroviruses, namely Jaagsiekte Sheep RetroVirus (JSRV) and Enzootic Nasal Tumour Virus (ENTV). Under field conditions, these viruses induce transformation of differentiated epithelial cells in the lungs for Jaagsiekte Sheep RetroVirus or the nasal cavities for Enzootic Nasal Tumour Virus. As in other vertebrates, a family of endogenous retroviruses named endogenous Jaagsiekte Sheep RetroVirus (enJSRV) and closely related to exogenous Jaagsiekte Sheep RetroVirus is present in domestic and wild small ruminants. Interestingly, Jaagsiekte Sheep RetroVirus and Enzootic Nasal Tumour Virus are able to promote cell transformation, leading to cancer through their envelope glycoproteins. In vitro, it has been demonstrated that the envelope is able to deregulate some of the important signaling pathways that control cell proliferation. The role of the retroviral envelope in cell transformation has attracted considerable attention in the past years, but it appears to be highly dependent of the nature and origin of the cells used. Aside from its health impact in animals, it has been reported for many years that the Jaagsiekte Sheep RetroVirus-induced lung cancer is analogous to a rare, peculiar form of lung adenocarcinoma in humans, namely lepidic pulmonary adenocarcinoma. The implication of a retrovirus related to Jaagsiekte Sheep RetroVirus is still controversial and under investigation, but the identification of an infectious agent associated with the development of lepidic pulmonary adenocarcinomas might help us to understand cancer development. This review explores the mechanisms of induction of respiratory cancers in small ruminants and the possible link between retrovirus and lepidic pulmonary adenocarcinomas in humans.
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Affiliation(s)
- M Monot
- INRA UMR754-Université Lyon 1, Retrovirus and Comparative Pathology, France; Université de Lyon, France
| | - F Archer
- INRA UMR754-Université Lyon 1, Retrovirus and Comparative Pathology, France; Université de Lyon, France
| | - M Gomes
- INRA UMR754-Université Lyon 1, Retrovirus and Comparative Pathology, France; Université de Lyon, France
| | - J-F Mornex
- INRA UMR754-Université Lyon 1, Retrovirus and Comparative Pathology, France; Université de Lyon, France; Hospices Civils de Lyon, France
| | - C Leroux
- INRA UMR754-Université Lyon 1, Retrovirus and Comparative Pathology, France; Université de Lyon, France.
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Watanabe Y, Yamamoto H, Oikawa R, Toyota M, Yamamoto M, Kokudo N, Tanaka S, Arii S, Yotsuyanagi H, Koike K, Itoh F. DNA methylation at hepatitis B viral integrants is associated with methylation at flanking human genomic sequences. Genome Res 2015; 25:328-37. [PMID: 25653310 PMCID: PMC4352876 DOI: 10.1101/gr.175240.114] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Integration of DNA viruses into the human genome plays an important role in various types of tumors, including hepatitis B virus (HBV)–related hepatocellular carcinoma. However, the molecular details and clinical impact of HBV integration on either human or HBV epigenomes are unknown. Here, we show that methylation of the integrated HBV DNA is related to the methylation status of the flanking human genome. We developed a next-generation sequencing-based method for structural methylation analysis of integrated viral genomes (denoted G-NaVI). This method is a novel approach that enables enrichment of viral fragments for sequencing using unique baits based on the sequence of the HBV genome. We detected integrated HBV sequences in the genome of the PLC/PRF/5 cell line and found variable levels of methylation within the integrated HBV genomes. Allele-specific methylation analysis revealed that the HBV genome often became significantly methylated when integrated into highly methylated host sites. After integration into unmethylated human genome regions such as promoters, however, the HBV DNA remains unmethylated and may eventually play an important role in tumorigenesis. The observed dynamic changes in DNA methylation of the host and viral genomes may functionally affect the biological behavior of HBV. These findings may impact public health given that millions of people worldwide are carriers of HBV. We also believe our assay will be a powerful tool to increase our understanding of the various types of DNA virus-associated tumorigenesis.
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Affiliation(s)
- Yoshiyuki Watanabe
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki 216-8511, Japan; Internal Medicine, Kawasaki Rinko General Hospital, Kawasaki 210-0806, Japan
| | - Hiroyuki Yamamoto
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki 216-8511, Japan
| | - Ritsuko Oikawa
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki 216-8511, Japan
| | - Minoru Toyota
- Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan
| | - Masakazu Yamamoto
- Department of Surgery, Institute of Gastroenterology, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Norihiro Kokudo
- Hepato-Biliary-Pancreatic Surgery Division, Artificial Organ and Transplantation Division, Department of Surgery, Graduate School of Medicine, University of Tokyo 113-8655, Japan
| | - Shinji Tanaka
- Department of Hepatobiliary Pancreatic Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo 113-0034, Japan
| | - Shigeki Arii
- Department of Hepatobiliary Pancreatic Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo 113-0034, Japan
| | - Hiroshi Yotsuyanagi
- Department of Infectious Diseases, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan
| | - Kazuhiko Koike
- Department of Gastroenterology, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan
| | - Fumio Itoh
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki 216-8511, Japan
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Abstract
To replicate their genomes in cells and generate new progeny, viruses typically require factors provided by the cells that they have infected. Subversion of the cellular machinery that controls replication of the infected host cell is a common activity of many viruses. Viruses employ different strategies to deregulate cell cycle checkpoint controls and modulate cell proliferation pathways. A number of DNA and RNA viruses encode proteins that target critical cell cycle regulators to achieve cellular conditions that are beneficial for viral replication. Many DNA viruses induce quiescent cells to enter the cell cycle; this is thought to increase pools of deoxynucleotides and thus, facilitate viral replication. In contrast, some viruses can arrest cells in a particular phase of the cell cycle that is favorable for replication of the specific virus. Cell cycle arrest may inhibit early cell death of infected cells, allow the cells to evade immune defenses, or help promote virus assembly. Although beneficial for the viral life cycle, virus-mediated alterations in normal cell cycle control mechanisms could have detrimental effects on cellular physiology and may ultimately contribute to pathologies associated with the viral infection, including cell transformation and cancer progression and maintenance. In this chapter, we summarize various strategies employed by DNA and RNA viruses to modulate the replication cycle of the virus-infected cell. When known, we describe how these virus-associated effects influence replication of the virus and contribute to diseases associated with infection by that specific virus.
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Affiliation(s)
- Eishi Noguchi
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania USA
| | - Mariana C. Gadaleta
- Dept of Biochemistry & Molecular Biology, Drexel University College of Medicine, Philadelphia, USA
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Avanzi S, Alvisi G, Ripalti A. How virus persistence can initiate the tumorigenesis process. World J Virol 2013; 2:102-9. [PMID: 24175234 PMCID: PMC3785046 DOI: 10.5501/wjv.v2.i2.102] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 04/04/2013] [Accepted: 04/10/2013] [Indexed: 02/05/2023] Open
Abstract
Human oncogenic viruses are defined as necessary but not sufficient to initiate cancer. Experimental evidence suggests that the oncogenic potential of a virus is effective in cells that have already accumulated a number of genetic mutations leading to cell cycle deregulation. Current models for viral driven oncogenesis cannot explain why tumor development in carriers of tumorigenic viruses is a very rare event, occurring decades after virus infection. Considering that viruses are mutagenic agents per se and human oncogenic viruses additionally establish latent and persistent infections, we attempt here to provide a general mechanism of tumor initiation both for RNA and DNA viruses, suggesting viruses could be both necessary and sufficient in triggering human tumorigenesis initiation. Upon reviewing emerging evidence on the ability of viruses to induce DNA damage while subverting the DNA damage response and inducing epigenetic disturbance in the infected cell, we hypothesize a general, albeit inefficient hit and rest mechanism by which viruses may produce a limited reservoir of cells harboring permanent damage that would be initiated when the virus first hits the cell, before latency is established. Cells surviving virus generated damage would consequently become more sensitive to further damage mediated by the otherwise insufficient transforming activity of virus products expressed in latency, or upon episodic reactivations (viral persistence). Cells with a combination of genetic and epigenetic damage leading to a cancerous phenotype would emerge very rarely, as the probability of such an occurrence would be dependent on severity and frequency of consecutive hit and rest cycles due to viral reinfections and reactivations.
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8
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Nascimento R, Costa H, Parkhouse RME. Virus manipulation of cell cycle. PROTOPLASMA 2012; 249:519-528. [PMID: 21986922 DOI: 10.1007/s00709-011-0327-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 09/28/2011] [Indexed: 05/31/2023]
Abstract
Viruses depend on host cell resources for replication and access to those resources may be limited to a particular phase of the cell cycle. Thus manipulation of cell cycle is a commonly employed strategy of viruses for achieving a favorable cellular environment. For example, viruses capable of infecting nondividing cells induce S phase in order to activate the host DNA replication machinery and provide the nucleotide triphosphates necessary for viral DNA replication (Flemington in J Virol 75:4475-4481, 2001; Sullivan and Pipas in Microbiol Mol Biol Rev 66:179-202, 2002). Viruses have developed several strategies to subvert the cell cycle by association with cyclin and cyclin-dependent kinase complexes and molecules that regulate their activity. Viruses tend to act on cellular proteins involved in a network of interactions in a way that minimal protein-protein interactions lead to a major effect. The complex and interactive nature of intracellular signaling pathways controlling cell division affords many opportunities for virus manipulation strategies. Taking the maxim "Set a thief to catch a thief" as a counter strategy, however, provides us with the very same virus evasion strategies as "ready-made tools" for the development of novel antivirus therapeutics. The most obvious are attenuated virus vaccines with critical evasion genes deleted. Similarly, vaccines against viruses causing cancer are now being successfully developed. Finally, as viruses have been playing chess with our cell biology and immune responses for millions of years, the study of their evasion strategies will also undoubtedly reveal new control mechanisms and their corresponding cellular intracellular signaling pathways.
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Affiliation(s)
- R Nascimento
- Instituto Gulbenkian de Ciencia, Oeiras, Portugal.
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9
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Lu JW, Hsia Y, Tu HC, Hsiao YC, Yang WY, Wang HD, Yuh CH. Liver development and cancer formation in zebrafish. ACTA ACUST UNITED AC 2011; 93:157-72. [DOI: 10.1002/bdrc.20205] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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10
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Park IS, Chang X, Loyo M, Wu G, Chuang A, Kim MS, Chae YK, Lyford-Pike S, Westra WH, Saunders JR, Sidransky D, Pai SI. Characterization of the methylation patterns in human papillomavirus type 16 viral DNA in head and neck cancers. Cancer Prev Res (Phila) 2011; 4:207-17. [PMID: 21292634 DOI: 10.1158/1940-6207.capr-10-0147] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Human papillomavirus (HPV) type 16 can integrate into the host genome, thereby rendering the viral coding genes susceptible to epigenetic modification. Using bisulfite genomic sequencing, we determined the methylation status of all 110 CpG sites within the viral epigenome in advanced stage III/IV HPV-16-associated head and neck cancers. We found that the viral genome was hypomethylated in the majority of head and neck cancers, in particular within the viral regulatory region, long control region (LCR), which controls transcription of the E6 and E7 oncogenes. The hypomethylation status of LCR correlated with detectable levels of E6 and E7 expression, which suggests that the tumors may still be dependent on these viral oncogenes to maintain the malignant phenotype. In addition to the methylation status of LCR, we report other potential factors which may influence intratumoral E6 and E7 expression including viral copy number and integration site. We were able to detect the viral epigenetic alterations in sampled body fluids, such as serum and saliva, which correlated with the changes observed in the primary tumors. Because viral epigenetic changes occur in the setting of viral integration into the human genome, the detection of methylated HPV genes in the serum and/or saliva may have diagnostic potential for early detection strategies of viral integration and assessment of risk for cancer development in high-risk individuals. Our findings also support continued targeting of the E6 and/or E7 antigens through various vaccine strategies against HPV-associated cancers.
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Affiliation(s)
- Il-Seok Park
- Departments of Otolaryngology-Head and Neck Surgery, The Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA
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Poreba E, Broniarczyk JK, Gozdzicka-Jozefiak A. Epigenetic mechanisms in virus-induced tumorigenesis. Clin Epigenetics 2011; 2:233-47. [PMID: 22704339 PMCID: PMC3365383 DOI: 10.1007/s13148-011-0026-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2010] [Accepted: 02/28/2011] [Indexed: 12/14/2022] Open
Abstract
About 15–20% of human cancers worldwide have viral etiology. Emerging data clearly indicate that several human DNA and RNA viruses, such as human papillomavirus, Epstein–Barr virus, Kaposi’s sarcoma-associated herpesvirus, hepatitis B virus, hepatitis C virus, and human T-cell lymphotropic virus, contribute to cancer development. Human tumor-associated viruses have evolved multiple molecular mechanisms to disrupt specific cellular pathways to facilitate aberrant replication. Although oncogenic viruses belong to different families, their strategies in human cancer development show many similarities and involve viral-encoded oncoproteins targeting the key cellular proteins that regulate cell growth. Recent studies show that virus and host interactions also occur at the epigenetic level. In this review, we summarize the published information related to the interactions between viral proteins and epigenetic machinery which lead to alterations in the epigenetic landscape of the cell contributing to carcinogenesis.
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Affiliation(s)
- Elzbieta Poreba
- Department of Molecular Virology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland
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12
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Chaurushiya MS, Weitzman MD. Viral manipulation of DNA repair and cell cycle checkpoints. DNA Repair (Amst) 2009; 8:1166-76. [PMID: 19473887 DOI: 10.1016/j.dnarep.2009.04.016] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Recognition and repair of DNA damage is critical for maintaining genomic integrity and suppressing tumorigenesis. In eukaryotic cells, the sensing and repair of DNA damage are coordinated with cell cycle progression and checkpoints, in order to prevent the propagation of damaged DNA. The carefully maintained cellular response to DNA damage is challenged by viruses, which produce a large amount of exogenous DNA during infection. Viruses also express proteins that perturb cellular DNA repair and cell cycle pathways, promoting tumorigenesis in their quest for cellular domination. This review presents an overview of strategies employed by viruses to manipulate DNA damage responses and cell cycle checkpoints as they commandeer the cell to maximize their own viral replication. Studies of viruses have identified key cellular regulators and revealed insights into molecular mechanisms governing DNA repair, cell cycle checkpoints, and transformation.
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Affiliation(s)
- Mira S Chaurushiya
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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13
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Conca P, Tarantino G. Hepatitis C virus lymphotropism and peculiar immunological phenotype: Effects on natural history and antiviral therapy. World J Gastroenterol 2009; 15:2305-8. [PMID: 19452570 PMCID: PMC2684594 DOI: 10.3748/wjg.15.2305] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) has been recognized to be both a hepato- and lymphotropic virus. HCV lymphotropism represents an essential lap in the pathogenesis of virus-related autoimmune and lymphoproliferative disorders, ranging from clonal expansion of B-cells with organ- and non-organ-specific autoantibody production up to overt non-Hodgkin’s lymphoma along a continuous step-by-step model of B-cell lymphomagenesis, where the intermediated mixed cryoglobulinemia could be considered as a stage of suppressible antigen-driven lymphoproliferation. HCV infection of lymphoid cells could set up privileged reservoirs able to interfere with the host viral clearance efficiency and may be implicated in viral recurrence after apparently successful antiviral therapy. The HCV long-lasting extrahepatic replicative state generates an abnormal systemic immunological response, easily detectable by searching simple laboratory and clinical parameters, mainly represented by vasculitis-like skin features and hypocomplementemia. The presence or absence of this hypersensitivity pattern seems to correlate with the antiviral response and could be identified as a novel immunological cofactor. Further research is required to fully verify the real impact on therapeutic choice/regimen.
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Fernandez AF, Rosales C, Lopez-Nieva P, Graña O, Ballestar E, Ropero S, Espada J, Melo SA, Lujambio A, Fraga MF, Pino I, Javierre B, Carmona FJ, Acquadro F, Steenbergen RD, Snijders PJ, Meijer CJ, Pineau P, Dejean A, Lloveras B, Capella G, Quer J, Buti M, Esteban JI, Allende H, Rodriguez-Frias F, Castellsague X, Minarovits J, Ponce J, Capello D, Gaidano G, Cigudosa JC, Gomez-Lopez G, Pisano DG, Valencia A, Piris MA, Bosch FX, Cahir-McFarland E, Kieff E, Esteller M. The dynamic DNA methylomes of double-stranded DNA viruses associated with human cancer. Genes Dev 2009; 19:438-51. [PMID: 19208682 PMCID: PMC2661803 DOI: 10.1101/gr.083550.108] [Citation(s) in RCA: 184] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The natural history of cancers associated with virus exposure is intriguing, since only a minority of human tissues infected with these viruses inevitably progress to cancer. However, the molecular reasons why the infection is controlled or instead progresses to subsequent stages of tumorigenesis are largely unknown. In this article, we provide the first complete DNA methylomes of double-stranded DNA viruses associated with human cancer that might provide important clues to help us understand the described process. Using bisulfite genomic sequencing of multiple clones, we have obtained the DNA methylation status of every CpG dinucleotide in the genome of the Human Papilloma Viruses 16 and 18 and Human Hepatitis B Virus, and in all the transcription start sites of the Epstein-Barr Virus. These viruses are associated with infectious diseases (such as hepatitis B and infectious mononucleosis) and the development of human tumors (cervical, hepatic, and nasopharyngeal cancers, and lymphoma), and are responsible for 1 million deaths worldwide every year. The DNA methylomes presented provide evidence of the dynamic nature of the epigenome in contrast to the genome. We observed that the DNA methylome of these viruses evolves from an unmethylated to a highly methylated genome in association with the progression of the disease, from asymptomatic healthy carriers, through chronically infected tissues and pre-malignant lesions, to the full-blown invasive tumor. The observed DNA methylation changes have a major functional impact on the biological behavior of the viruses.
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Affiliation(s)
- Agustin F. Fernandez
- Cancer Epigenetics Group, Spanish National Cancer Research Centre (CNIO), Madrid E-28029, Spain
- Cancer Epigenetics and Biology Program, Bellvitge Institute for Biomedical Research-Catalan Institute of Oncology (IDIBELL-ICO), Barcelona, Catalonia 08907, Spain
| | - Cecilia Rosales
- Cancer Epigenetics Group, Spanish National Cancer Research Centre (CNIO), Madrid E-28029, Spain
| | - Pilar Lopez-Nieva
- Cancer Epigenetics Group, Spanish National Cancer Research Centre (CNIO), Madrid E-28029, Spain
| | - Osvaldo Graña
- Bioinformatics Unit and Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre, Madrid E-28029, Spain
| | - Esteban Ballestar
- Cancer Epigenetics Group, Spanish National Cancer Research Centre (CNIO), Madrid E-28029, Spain
| | - Santiago Ropero
- Cancer Epigenetics Group, Spanish National Cancer Research Centre (CNIO), Madrid E-28029, Spain
| | - Jesus Espada
- Cancer Epigenetics Group, Spanish National Cancer Research Centre (CNIO), Madrid E-28029, Spain
| | - Sonia A. Melo
- Cancer Epigenetics Group, Spanish National Cancer Research Centre (CNIO), Madrid E-28029, Spain
| | - Amaia Lujambio
- Cancer Epigenetics Group, Spanish National Cancer Research Centre (CNIO), Madrid E-28029, Spain
| | - Mario F. Fraga
- Cancer Epigenetics Group, Spanish National Cancer Research Centre (CNIO), Madrid E-28029, Spain
| | - Irene Pino
- Cancer Epigenetics Group, Spanish National Cancer Research Centre (CNIO), Madrid E-28029, Spain
| | - Biola Javierre
- Cancer Epigenetics Group, Spanish National Cancer Research Centre (CNIO), Madrid E-28029, Spain
| | - Francisco J. Carmona
- Cancer Epigenetics Group, Spanish National Cancer Research Centre (CNIO), Madrid E-28029, Spain
- Cancer Epigenetics and Biology Program, Bellvitge Institute for Biomedical Research-Catalan Institute of Oncology (IDIBELL-ICO), Barcelona, Catalonia 08907, Spain
| | - Francesco Acquadro
- Molecular Cytogenetics Group and CIBERER, Human Cancer Genetics Programme, Spanish National Cancer Research Centre, Madrid E-28029, Spain
| | - Renske D.M. Steenbergen
- Department of Pathology, Unit of Molecular Pathology, Vrije Universiteit Medical Center, Amsterdam 1007 MB, The Netherlands
| | - Peter J.F. Snijders
- Department of Pathology, Unit of Molecular Pathology, Vrije Universiteit Medical Center, Amsterdam 1007 MB, The Netherlands
| | - Chris J. Meijer
- Department of Pathology, Unit of Molecular Pathology, Vrije Universiteit Medical Center, Amsterdam 1007 MB, The Netherlands
| | - Pascal Pineau
- Nuclear Organization and Oncogenesis Unit, INSERM U579, Pasteur Institute, Paris 75724, France
| | - Anne Dejean
- Nuclear Organization and Oncogenesis Unit, INSERM U579, Pasteur Institute, Paris 75724, France
| | - Belen Lloveras
- Translational Research Laboratory, Catalan Institute of Oncology (ICO), Barcelona, Catalonia 08907, Spain
| | - Gabriel Capella
- Translational Research Laboratory, Catalan Institute of Oncology (ICO), Barcelona, Catalonia 08907, Spain
| | - Josep Quer
- Liver Unit, Department of Medicine, Hospital Vall Hebron, and Universitat Autonoma Barcelona and CIBEREHD, Barcelona 08035, Spain
| | - Maria Buti
- Liver Unit, Department of Medicine, Hospital Vall Hebron, and Universitat Autonoma Barcelona and CIBEREHD, Barcelona 08035, Spain
| | - Juan-Ignacio Esteban
- Liver Unit, Department of Medicine, Hospital Vall Hebron, and Universitat Autonoma Barcelona and CIBEREHD, Barcelona 08035, Spain
| | - Helena Allende
- Pathology Department, Hospital Vall Hebron, Barcelona 08035, Spain
| | | | - Xavier Castellsague
- Service of Epidemiology and Cancer Register, Catalan Institute of Oncology (ICO), Barcelona, Catalonia 08907, Spain
| | - Janos Minarovits
- Microbiological Reseach Group, National Center for Epidemiology, Budapest 1529, Hungary
| | - Jordi Ponce
- Service of Gynecology, Hospital Universitari de Bellvitge, L'Hospitalet, Catalonia 08907, Spain
| | - Daniela Capello
- Division of Hematology, Department of Clinical and Experimental Medicine and Department of Oncology, Amedeo Avogadro University of Eastern Piedmont, Vercelli, Alessandria, Novara 13100, Italy
| | - Gianluca Gaidano
- Division of Hematology, Department of Clinical and Experimental Medicine and Department of Oncology, Amedeo Avogadro University of Eastern Piedmont, Vercelli, Alessandria, Novara 13100, Italy
| | - Juan Cruz Cigudosa
- Molecular Cytogenetics Group and CIBERER, Human Cancer Genetics Programme, Spanish National Cancer Research Centre, Madrid E-28029, Spain
| | - Gonzalo Gomez-Lopez
- Bioinformatics Unit and Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre, Madrid E-28029, Spain
- Biomedical Foundation Complexo Hospitalario, Universitario de Vigo (CHUVI), Vigo 36211, Spain
| | - David G. Pisano
- Bioinformatics Unit and Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre, Madrid E-28029, Spain
| | - Alfonso Valencia
- Bioinformatics Unit and Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre, Madrid E-28029, Spain
| | - Miguel Angel Piris
- Lymphoma Group, Molecular Pathology Programme, Spanish National Cancer Research Centre, Madrid E-28029, Spain
| | - Francesc X. Bosch
- Service of Epidemiology and Cancer Register, Catalan Institute of Oncology (ICO), Barcelona, Catalonia 08907, Spain
| | - Ellen Cahir-McFarland
- Departments of Medicine, Microbiology, and Molecular Genetics, Harvard University, Boston, Massachusetts 02115, USA
| | - Elliott Kieff
- Departments of Medicine, Microbiology, and Molecular Genetics, Harvard University, Boston, Massachusetts 02115, USA
- Infectious Disease Division, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
| | - Manel Esteller
- Cancer Epigenetics Group, Spanish National Cancer Research Centre (CNIO), Madrid E-28029, Spain
- Cancer Epigenetics and Biology Program, Bellvitge Institute for Biomedical Research-Catalan Institute of Oncology (IDIBELL-ICO), Barcelona, Catalonia 08907, Spain
- Institucio Catalana de Recerca i Estudis Avançats (ICREA), Barcelona 08010, Spain
- Corresponding author.E-mail ; fax 34-91-2246923
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15
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Affiliation(s)
- Clara Balsano
- Dipartimento di Medicina Interna e Sanità Pubblica (MISP), University of L'Aquila, L'Aquila, Italy.
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16
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Abstract
The inherent immortality of embryonic stem cells demonstrates that replicative senescence as possibly the aging of species are epigenetic phenomena. The cellular level of expression of the housekeeping molecular chaperones correlates with longevity and cancer resistance of species. The chaperones are cancer antagonists by acting as genetic buffers, stabilizing the normal phenotype. Probably the progressive age-related silencing of the housekeeping genes contributes to the phenotype of aging, with the associated increase in cancer incidence. The present review concerns epigenetic chemical, immunological, and hormonal mechanisms, activating chaperone- and immune-response genes, which have proved effective in increasing longevity and cancer resistance. The relation of steroid hormone levels to species longevity, the anticarcinogenic activity of pregnancy hormones, and the influence of hormones on the longevity of social insects, illustrates the importance of hormonal mechanisms for the activation of longevity genes.
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Affiliation(s)
- Jens Krøll
- Hafnia Unit of Biogerontology, Godthåbsvej 111,3 DK-2000, Frederiksberg, Denmark.
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17
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Leroux C, Girard N, Cottin V, Greenland T, Mornex JF, Archer F. Jaagsiekte Sheep Retrovirus (JSRV): from virus to lung cancer in sheep. Vet Res 2007; 38:211-28. [PMID: 17257570 DOI: 10.1051/vetres:2006060] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Accepted: 11/23/2006] [Indexed: 01/16/2023] Open
Abstract
Jaagsiekte Sheep Retrovirus (JSRV) is a betaretrovirus infecting sheep. This virus is responsible for a pulmonary adenocarcinoma, by transformation of epithelial cells from the bronchioli and alveoli. This animal cancer is similar to human bronchioloalveolar cancer (BAC), a specific form of human lung cancer for which a viral aetiology has not yet been identified. JSRV interacts with target cells through the membrane receptor Hyal2. The JSRV genome is simple and contains no recognised oncogene. It is now well established that the viral envelope protein is oncogenic by itself, via the cytoplasmic domain of the transmembrane glycoprotein and some domains of the surface glycoprotein. Activation of the PI3K/Akt and MAPK pathways participates in the envelope-induced transformation. Tumour development is associated with telomerase activation. This review will focus on the induction of cancer by JSRV.
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Affiliation(s)
- Caroline Leroux
- Université de Lyon 1, INRA, UMR754, Ecole Nationale Vétérinaire de Lyon, IFR 128, F-69007, Lyon, France.
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18
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Fisher SG, Fisher RI. The emerging concept of antigen-driven lymphomas: epidemiology and treatment implications. Curr Opin Oncol 2006; 18:417-24. [PMID: 16894287 DOI: 10.1097/01.cco.0000239878.31463.0b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW Dramatic increases in the incidence of lymphomas worldwide have stimulated considerable efforts to identify factors that contribute to the etiology of this heterogeneous group of malignancies. The treatment and, ultimately, the prevention of lymphoma depend on our understanding of the complex interaction of exogenous agents with the molecular milieu which initiates and sustains a lymphoid malignancy. This review discusses the current evidence for the role of foreign or self antigens in the initiation of lymphomagenesis. RECENT FINDINGS Recent data have demonstrated an increased risk of lymphoma among individuals with chronic inflammatory conditions, persistent infections or immunodeficient states. Common to these clinical conditions is antigenic stimulation leading to an inflammatory cascade of cellular and cytokine reactions that may tax the host immune response, provoke tissue injury and eventually result in lymphoid neoplasia. SUMMARY Efforts to detect and suppress chronic, antigen-driven inflammation have suggested that neoplastic progression may often be interrupted and controlled. Elucidation of the etiologic mechanisms critical to the survival of these malignancies would provide promising alternatives for the prevention and treatment of some lymphomas.
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Affiliation(s)
- Susan G Fisher
- Division of Epidemiology, Department of Community & Preventive Medicine and James P. Wilmot Cancer Center, University of Rochester, Rochester, New York 14642, USA.
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19
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Cougot D, Wu Y, Cairo S, Caramel J, Renard CA, Lévy L, Buendia MA, Neuveut C. The hepatitis B virus X protein functionally interacts with CREB-binding protein/p300 in the regulation of CREB-mediated transcription. J Biol Chem 2006; 282:4277-4287. [PMID: 17158882 DOI: 10.1074/jbc.m606774200] [Citation(s) in RCA: 162] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The hepatitis B virus infects more than 350 million people worldwide and is a leading cause of liver cancer. The virus encodes a multifunctional regulator, the hepatitis B virus X protein (HBx), that is essential for virus replication. HBx is involved in modulating signal transduction pathways and transcription mediated by various factors, notably CREB that requires the recruitment of the co-activators CREB-binding protein (CBP)/p300. Here we investigated the role of HBx and its potential interaction with CBP/p300 in regulating CREB transcriptional activity. We show that HBx and CBP/p300 synergistically enhanced CREB activity and that CREB phosphorylation by protein kinase A was a prerequisite for the cooperative action of HBx and CBP/p300. We further show that HBx interacted directly with CBP/p300 in vitro and in vivo. Using chromatin immunoprecipitation, we provide evidence that HBx physically occupied the CREB-binding domain of CREB-responsive promoters of endogenous cellular genes such as interleukin 8 and proliferating cell nuclear antigen. Moreover expression of HBx increased the recruitment of p300 to the interleukin 8 and proliferating cell nuclear antigen promoters in cells, and this is associated with increased gene expression. As recruitment of CBP/p300 is known to represent the limiting event for activating CREB target genes, HBx may disrupt this cellular regulation, thus predisposing cells to transformation.
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Affiliation(s)
- Delphine Cougot
- Unité d'Oncogene`se et Virologie Moléculaire, Institut Pasteur and INSERM U579, 28 rue du Dr. Roux, 75015 Paris, France
| | - Yuanfei Wu
- Unité d'Oncogene`se et Virologie Moléculaire, Institut Pasteur and INSERM U579, 28 rue du Dr. Roux, 75015 Paris, France
| | - Stefano Cairo
- Unité d'Oncogene`se et Virologie Moléculaire, Institut Pasteur and INSERM U579, 28 rue du Dr. Roux, 75015 Paris, France
| | - Julie Caramel
- Unité d'Oncogene`se et Virologie Moléculaire, Institut Pasteur and INSERM U579, 28 rue du Dr. Roux, 75015 Paris, France
| | - Claire-Angélique Renard
- Unité d'Oncogene`se et Virologie Moléculaire, Institut Pasteur and INSERM U579, 28 rue du Dr. Roux, 75015 Paris, France
| | - Laurence Lévy
- Unité d'Oncogene`se et Virologie Moléculaire, Institut Pasteur and INSERM U579, 28 rue du Dr. Roux, 75015 Paris, France
| | - Marie Annick Buendia
- Unité d'Oncogene`se et Virologie Moléculaire, Institut Pasteur and INSERM U579, 28 rue du Dr. Roux, 75015 Paris, France
| | - Christine Neuveut
- Unité d'Oncogene`se et Virologie Moléculaire, Institut Pasteur and INSERM U579, 28 rue du Dr. Roux, 75015 Paris, France.
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20
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Hersoug LG, Arnau J. A built-in co-carcinogenic effect due to viruses involved in latent or persistent infections. Med Hypotheses 2006; 68:1001-8. [PMID: 17125934 DOI: 10.1016/j.mehy.2006.10.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2006] [Accepted: 10/03/2006] [Indexed: 11/29/2022]
Abstract
A new hypothesis for some cancers, which combines the chromosomal instability theories with a co-carcinogenic effect of viruses causing latent or persistent infection, is presented. The hypothesis incorporates the multi-step model of cancer and that pre-cancerous cells reach a state of chromosomal instability. Because of chromosomal instability, the genome of these cell lines will lead to changes from generation to generation and will face a remarkable selection pressure both from lost traits, apoptosis, and from the immune system. Viruses causing latent or persistent infections have evolved many different genes capable to evade the immune system. If these viruses are harboured in the genome of pre-cancerous cells they could provide them with "superpowers" and with genes that may assist the cells to elude the immune system. The theory explains why cancer predominantly is a disease of old age. Upon aging, the immune system becomes reduced including the ability to control and suppress the viruses that cause latent or persistent infections. The risk of cancer could thereby increase as the immune functions decrease. The theory provides new insights to the genesis of cancers.
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Affiliation(s)
- Lars-Georg Hersoug
- Research Centre for Prevention and Health, Glostrup University Hospital, 57 Nrd Ringvej, Building 84/85, DK-2600 Glostrup, Denmark.
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21
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Shadan FF. A circadian model for viral persistence. Med Hypotheses 2006; 68:546-53. [PMID: 17030450 DOI: 10.1016/j.mehy.2006.08.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2006] [Accepted: 08/11/2006] [Indexed: 01/20/2023]
Abstract
Persistently infecting DNA viruses depend heavily on host cell DNA synthesis machinery. Replication of cellular and viral DNA is inhibited by mutagenic stress. It is hypothesized that diurnal regulation of viral DNA replication may occur at the level of cell cycle checkpoints and DNA repair, to protect DNA from exposure to UV light or other mutagens. This highly conserved mechanism is traced back to viruses that persist in prokaryotes and eukaryotes. Inhibition of viral DNA replication and the cell cycle in response to UV light may represent a functional building block in the evolution of circadian-gated DNA replication. Viral DNA replication appears to be closely linked to the circadian clock by interaction of viral promoters, early viral proteins and transcription factors. It is proposed here that under certain conditions viral oncogene expression is phase-shifted relative to that of tumor suppressor and DNA repair genes. The resulting desynchrony of checkpoint controls and DNA repair from diurnal genotoxic exposure produces cyclic periods of suboptimal response to DNA damage. This temporal vulnerability to genotoxic stress produces a "mutator phenotype" with inherent genome instability. The proposed model delineates areas of research with implications for viral pathogenesis and therapeutics.
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Affiliation(s)
- Farhad F Shadan
- The Scripps Research Institute and Scripps Clinic, 10666 N. Torrey Pines Road, 403C, La Jolla, CA 92037, USA.
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22
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Gatza ML, Marriott SJ. Genotoxic stress and cellular stress alter the subcellular distribution of human T-cell leukemia virus type 1 tax through a CRM1-dependent mechanism. J Virol 2006; 80:6657-68. [PMID: 16775353 PMCID: PMC1488944 DOI: 10.1128/jvi.02270-05] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Accepted: 04/14/2006] [Indexed: 12/17/2022] Open
Abstract
Human T-cell leukemia virus type 1 Tax is a predominantly nuclear viral oncoprotein that colocalizes with cellular proteins in nuclear foci known as Tax speckled structures (TSS). Tax is also diffusely distributed throughout the cytoplasm, where it interacts with and affects the functions of cytoplasmic cellular proteins. Mechanisms that regulate the distribution of Tax between the cytoplasm and nucleus remain to be identified. Since Tax has been shown to promote genome instability by perturbing cell cycle progression and DNA repair mechanisms following DNA damage, we examined the effect of genotoxic stress on the subcellular distribution and interacting partners of Tax. Tax localization was altered in response to various forms of cellular stress, resulting in an increase in cytoplasmic Tax and a decrease in Tax speckled structures. Concomitantly, colocalization of Tax with sc35 (a TSS protein) decreased following stress. Tax translocation required the CRM1 nuclear export pathway, and a transient interaction between Tax and CRM1 was observed following stress. These results suggest that the subcellular distribution of Tax and the interactions between Tax and cellular proteins respond dynamically to cellular stress. Changes in Tax distribution and interacting partners are likely to affect cellular processes that regulate cellular transformation.
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Affiliation(s)
- Michael L Gatza
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, One Baylor Plaza MS-385, Houston, TX 77030, USA
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23
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Karpinets TV, Foy BD. Tumorigenesis: the adaptation of mammalian cells to sustained stress environment by epigenetic alterations and succeeding matched mutations. Carcinogenesis 2005; 26:1323-34. [PMID: 15802302 DOI: 10.1093/carcin/bgi079] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Recent studies indicate that during tumorigenic transformations, cells may generate mutations by themselves as a result of error-prone cell division with participation of error-prone polymerases and aberrant mitosis. These mechanisms may be activated in cells by continuing proliferative and survival signaling in a sustained stress environment (SSE). The paper hypothesizes that long-term exposure to this signaling epigenetically reprograms the genome of some cells and, in addition, leads to their senescence. The epigenetic reprogramming results in: (i) hypermethylation of tumor-suppressor genes involved in the onset of cell-cycle arrest, apoptosis and DNA repair; (ii) hypomethylation of proto-oncogenes associated with persistent proliferative activity; and (iii) the global demethylation of the genome and activation of DNA repeats. These epigenetic changes in the proliferating cells associate with their replicative senescence and allow the reprogrammed senescent cells to overcome the cell-cycle arrest and to activate error-prone replications. It is hypothesized that the generation of mutations in the error-prone replications of the epigenetically reprogrammed cells is not random. The mutations match epigenetic alterations in the cellular genome, namely gain of function mutations in the case of hypomethylation and loss of functions in the case of hypermethylation. In addition, continuing proliferation of the cells imposed by signaling in SSE speeds up the natural selection of the mutant cells favoring the survival of the cells with mutations that are beneficial in the environment. In this way, a stress-induced replication of the cells epigenetically reprograms their genome for quick adaptation to stressful environments providing an increased rate of mutations, epigenetic tags to beneficial mutations and quick selection process. In combination, these processes drive the origin of the transformed mammalian cells, cancer development and progression. Support from genomic, biochemical and medical studies for the proposed hypothesis, and its implementations are discussed.
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Affiliation(s)
- Tatiana V Karpinets
- Department of Plant Sciences, University of Tennessee, 2431 Center Drive Knoxville, TN 37996-4500, USA.
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24
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Abstract
Viruses of the retrovirus and herpesvirus families are aetiological agents of human leukaemias and lymphomas. The human T-cell leukaemia virus type 1 causes adult T-cell leukaemia and the Epstein-Barr virus is associated with Burkitt's lymphoma, lymphomas in immunosuppressed people, and Hodgkin lymphoma. The discovery of human herpesvirus type 8 has led to the identification of a rare and unusual group of virus-associated lymphoproliferative diseases. Individuals infected with the human immunodeficiency virus are at greatly increased risk of developing lymphoma but here the mechanism of lymphomagenesis is indirect. Recent data suggest that hepatitis C virus infection is also associated with an increased incidence of lymphoma, whereas data relating to SV40 remain controversial.
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Affiliation(s)
- Ruth F Jarrett
- LRF Virus Centre, Institute of Comparative Medicine, University of Glasgow, UK.
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