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Huang X, Zhang M, Zhang Z. The Role of LMP1 in Epstein-Barr Virus-associated Gastric Cancer. Curr Cancer Drug Targets 2024; 24:127-141. [PMID: 37183458 DOI: 10.2174/1568009623666230512153741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 03/29/2023] [Accepted: 04/06/2023] [Indexed: 05/16/2023]
Abstract
EBV promotes many cancers such as lymphoma, nasopharyngeal carcinoma, and gastric; Latent Membrane Protein 1 (LMP1) is considered to be a major oncogenic protein encoded by Epstein- Barr virus (EBV). LMP1 functions as a carcinogen in lymphoma and nasopharyngeal carcinoma, and LMP1 may also promote gastric cancer. The expression level of LMP1 in host cells is a key determinant in tumorigenesis and maintenance of virus specificity. By promoting cell immortalization and cell transformation, promoting cell proliferation, affecting immunity, and regulating cell apoptosis, LMP1 plays a crucial tumorigenic role in epithelial cancers. However, very little is currently known about LMP1 in Epstein-Barr virus-associated gastric cancer (EBVaGC); the main reason is that the expression level of LMP1 in EBVaGC is comparatively lower than other EBV-encoded proteins, such as The Latent Membrane Protein 2A (LMP2A), Epstein-Barr nuclear antigen 1 (EBNA1) and BamHI-A rightward frame 1 (BARF1), to date, there are few studies related to LMP1 in EBVaGC. Recent studies have demonstrated that LMP1 promotes EBVaGC by affecting The phosphatidylinositol 3-kinase- Akt (PI3K-Akt), Nuclear factor-kappa B (NF-κB), and other signaling pathways to regulate many downstream targets such as Forkhead box class O (FOXO), C-X-C-motif chemokine receptor (CXCR), COX-2 (Cyclooxygenase-2); moreover, the gene methylation induced by LMP1 in EBVaGC has become one of the characteristics that distinguish this gastric cancer (GC) from other types of gastric cancer and LMP1 also promotes the formation of the tumor microenvironment (TME) of EBVaGC in several ways. This review synthesizes previous relevant literature, aiming to highlight the latest findings on the mechanism of action of LMP1 in EBVaGC, summarize the function of LMP1 in EBVaGC, lay the theoretical foundation for subsequent new research on LMP1 in EBVaGC, and contribute to the development of novel LMP1-targeted drugs.
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Affiliation(s)
- Xinqi Huang
- Department of Clinical Medicine, Grade 20, Hengyang Medical College, University of South China, Hengyang, Hunan, 421001, China
| | - Meilan Zhang
- Cancer Research Institute of Hengyang Medical College, University of South China, Hengyang, Hunan, 421001, China
| | - Zhiwei Zhang
- Cancer Research Institute of Hengyang Medical College, University of South China, Hengyang, Hunan, 421001, China
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Ceraolo MG, Romero-Medina MC, Gobbato S, Melita G, Krynska H, Sirand C, Gupta P, Viarisio D, Robitaille A, Marvel J, Tommasino M, Venuti A, Gheit T. HPV38 impairs UV-induced transcriptional activation of the IL-18 pro-inflammatory cytokine. mSphere 2023; 8:e0045023. [PMID: 37877723 PMCID: PMC10732055 DOI: 10.1128/msphere.00450-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 09/13/2023] [Indexed: 10/26/2023] Open
Abstract
IMPORTANCE Here, we demonstrate that the direct binding of p53 on the IL-18 promoter region regulates its gene expression. However, the presence of E6 and E7 from human papillomavirus type 38 impairs this mechanism via a new inhibitory complex formed by DNA methyltransferase 1 (DNMT1)/PKR/ΔNp73α, which binds to the region formerly occupied by p53 in primary keratinocytes.
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Affiliation(s)
- Maria Grazia Ceraolo
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
| | | | - Simone Gobbato
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
| | - Giusi Melita
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
| | - Hanna Krynska
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
- Biotechnology and Cell Signaling (CNRS/Université de Strasbourg, UMR 7242), Ecole Superieure de Biotechnologie de Strasbourg, Boulevard Sébastien Brant, Illkirch, France
| | - Cecilia Sirand
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
| | - Purnima Gupta
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
| | | | - Alexis Robitaille
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
| | - Jacqueline Marvel
- CIRI, Centre International de Recherche en Infectiologie, Université Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, Université Lyon, Lyon, France
| | | | - Assunta Venuti
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
| | - Tarik Gheit
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
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3
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Taverniti V, Krynska H, Venuti A, Straub ML, Sirand C, Lohmann E, Romero-Medina MC, Moro S, Robitaille A, Negroni L, Martinez-Zapien D, Masson M, Tommasino M, Zanier K. The E2F4/p130 Repressor Complex Cooperates with Oncogenic ΔNp73α To Inhibit Gene Expression in Human Papillomavirus 38 E6/E7-Transformed Keratinocytes and in Cancer Cells. mSphere 2023; 8:e0005623. [PMID: 36883841 PMCID: PMC10117100 DOI: 10.1128/msphere.00056-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 02/09/2023] [Indexed: 03/09/2023] Open
Abstract
Tumor suppressor p53 and its related proteins, p63 and p73, can be synthesized as multiple isoforms lacking part of the N- or C-terminal regions. Specifically, high expression of the ΔNp73α isoform is notoriously associated with various human malignancies characterized by poor prognosis. This isoform is also accumulated by oncogenic viruses, such as Epstein-Barr virus (EBV), as well as genus beta human papillomaviruses (HPV) that appear to be involved in carcinogenesis. To gain additional insight into ΔNp73α mechanisms, we have performed proteomics analyses using human keratinocytes transformed by the E6 and E7 proteins of the beta-HPV type 38 virus as an experimental model (38HK). We find that ΔNp73α associates with the E2F4/p130 repressor complex through a direct interaction with E2F4. This interaction is favored by the N-terminal truncation of p73 characteristic of ΔNp73 isoforms. Moreover, it is independent of the C-terminal splicing status, suggesting that it could represent a general feature of ΔNp73 isoforms (α, β, γ, δ, ε, ζ, θ, η, and η1). We show that the ΔNp73α-E2F4/p130 complex inhibits the expression of specific genes, including genes encoding for negative regulators of proliferation, both in 38HK and in HPV-negative cancer-derived cell lines. Such genes are not inhibited by E2F4/p130 in primary keratinocytes lacking ΔNp73α, indicating that the interaction with ΔNp73α rewires the E2F4 transcriptional program. In conclusion, we have identified and characterized a novel transcriptional regulatory complex with potential implications in oncogenesis. IMPORTANCE The TP53 gene is mutated in about 50% of human cancers. In contrast, the TP63 and TP73 genes are rarely mutated but rather expressed as ΔNp63 and ΔNp73 isoforms in a wide range of malignancies, where they act as p53 antagonists. Accumulation of ΔNp63 and ΔNp73, which is associated with chemoresistance, can result from infection by oncogenic viruses such as EBV or HPV. Our study focuses on the highly carcinogenic ΔNp73α isoform and uses a viral model of cellular transformation. We unveil a physical interaction between ΔNp73α and the E2F4/p130 complex involved in cell cycle control, which rewires the E2F4/p130 transcriptional program. Our work shows that ΔNp73 isoforms can establish interactions with proteins that do not bind to the TAp73α tumor suppressor. This situation is analogous to the gain-of-function interactions of p53 mutants supporting cellular proliferation.
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Affiliation(s)
- Valerio Taverniti
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
| | - Hanna Krynska
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
- Biotechnology and Cell Signaling (CNRS/Université de Strasbourg, UMR 7242), Ecole Superieure de Biotechnologie de Strasbourg, Boulevard Sébastien Brant, Illkirch, France
| | - Assunta Venuti
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
| | - Marie-Laure Straub
- Biotechnology and Cell Signaling (CNRS/Université de Strasbourg, UMR 7242), Ecole Superieure de Biotechnologie de Strasbourg, Boulevard Sébastien Brant, Illkirch, France
| | - Cécilia Sirand
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
| | - Eugenie Lohmann
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
| | | | - Stefano Moro
- Biotechnology and Cell Signaling (CNRS/Université de Strasbourg, UMR 7242), Ecole Superieure de Biotechnologie de Strasbourg, Boulevard Sébastien Brant, Illkirch, France
| | - Alexis Robitaille
- International Agency for Research on Cancer (IARC), World Health Organization, Lyon, France
| | - Luc Negroni
- Proteomics platform, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC)/INSERM U964/CNRS UMR 7104/Université de Strasbourg, Illkirch, France
| | - Denise Martinez-Zapien
- Biotechnology and Cell Signaling (CNRS/Université de Strasbourg, UMR 7242), Ecole Superieure de Biotechnologie de Strasbourg, Boulevard Sébastien Brant, Illkirch, France
| | - Murielle Masson
- Biotechnology and Cell Signaling (CNRS/Université de Strasbourg, UMR 7242), Ecole Superieure de Biotechnologie de Strasbourg, Boulevard Sébastien Brant, Illkirch, France
| | | | - Katia Zanier
- Biotechnology and Cell Signaling (CNRS/Université de Strasbourg, UMR 7242), Ecole Superieure de Biotechnologie de Strasbourg, Boulevard Sébastien Brant, Illkirch, France
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Klatka M, Rysz I, Hymos A, Polak A, Mertowska P, Mertowski S, Smolak K, Grywalska E. Effect of Epstein-Barr Virus Infection on Selected Immunological Parameters in Children with Type 1 Diabetes. Int J Mol Sci 2023; 24:ijms24032392. [PMID: 36768715 PMCID: PMC9917181 DOI: 10.3390/ijms24032392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 01/27/2023] Open
Abstract
Diabetes mellitus is a group of metabolic disorders with different etiologies, pathogeneses and clinical pictures, characterized by chronic hyperglycemia due to abnormal insulin secretion or action. Type 1 diabetes mellitus is the most common type of diabetes mellitus in children and adolescents, accounting for about 90% of diabetes in the population under the age of 18. The etiopathogenesis of type 1 diabetes is multifactorial. The disease occurs as a result of the interaction of three factors: genetic predisposition, environmental factors and the immune response. Research in recent years has focused on the involvement of Epstein-Barr virus (EBV) in the pathogenesis of type I diabetes. The goals of treating type 1 diabetes include maintaining blood-glucose, fructosamine and glycated hemoglobin (HbA1c) levels; therefore, the main purpose of this study was to evaluate the effect of EBV infection on the activation of selected immune cells, fructosamine levels and HbA1c levels in children with type I diabetes. Based on our study, we found a lower percentage of CD8+ T lymphocytes with expression of the CD69 molecule in patients with anti-VCA antibodies in the IgG class, and a lower percentage of CD8+ T lymphocytes with expression of the CD25+ molecule in patients with anti-EBNA-1 antibodies in the IgG class, which may indicate limited control of the immune system during EBV infection in patients. There was a lower percentage of CD3+CD4+ T lymphocytes secreting IL-4 in the study group, indicating that a deficiency in IL-4 production may be related to the development of type 1 diabetes. There was an increase in the percentage of CD4+CD3+IL-10 lymphocytes in the study group with anti-VCA antibodies present in the IgG class and anti-EBNA-1 antibodies in the IgG class compared to the patients without antibodies. In addition, there was a significant increase in fructosamine levels and higher glycated hemoglobin levels in the study group with antibodies to EBV antigens. In addition, an increase in the percentage of T lymphocytes with a CD4+CD3+IL-17+ phenotype in the patients with anti-VCA IgG antibodies was confirmed, and higher HbA1c levels may suggest that EBV infection is accompanied by an increase in IL-17 secretion.
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Affiliation(s)
- Maria Klatka
- Department of Pediatric Endocrinology and Diabetology, Medical University of Lublin, 20-093 Lublin, Poland
| | - Izabela Rysz
- Department of Pediatric Endocrinology and Diabetology, Medical University of Lublin, 20-093 Lublin, Poland
| | - Anna Hymos
- Department of Experimental Immunology, Medical University of Lublin, 20-093 Lublin, Poland
| | - Agnieszka Polak
- Department of Endocrinology, Medical University of Lublin, 20-093 Lublin, Poland
| | - Paulina Mertowska
- Department of Experimental Immunology, Medical University of Lublin, 20-093 Lublin, Poland
- Correspondence: (P.M.); (S.M.)
| | - Sebastian Mertowski
- Department of Experimental Immunology, Medical University of Lublin, 20-093 Lublin, Poland
- Correspondence: (P.M.); (S.M.)
| | - Konrad Smolak
- Department of Experimental Immunology, Medical University of Lublin, 20-093 Lublin, Poland
| | - Ewelina Grywalska
- Department of Experimental Immunology, Medical University of Lublin, 20-093 Lublin, Poland
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5
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Li B, Chng WJ. EZH2 abnormalities in lymphoid malignancies: underlying mechanisms and therapeutic implications. J Hematol Oncol 2019; 12:118. [PMID: 31752930 PMCID: PMC6868783 DOI: 10.1186/s13045-019-0814-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 10/27/2019] [Indexed: 02/08/2023] Open
Abstract
EZH2 is the catalytic subunit of the polycomb repressive complex 2 (PRC2), which along with other PRC2 components mediates gene expression suppression via the methylation of Histone H3 at lysine 27. Recent studies have revealed a dichotomous role of EZH2 in physiology and in the pathogenesis of cancer. While it plays an essential role in the development of the lymphoid system, its deregulation, whether due to genetic or non-genetic causes, promotes B cell- and T cell-related lymphoma or leukemia. These findings triggered a boom in the development of therapeutic EZH2 inhibitors in recent years. Here, we discuss physiologic and pathogenic function of EZH2 in lymphoid context, various internal causes of EZH2 aberrance and how EZH2 modulates lymphomagenesis through epigenetic silencing, post-translational modifications (PTMs), orchestrating with surrounding tumor micro-environment and associating with RNA or viral partners. We also summarize different strategies to directly inhibit PRC2-EZH2 or to intervene EZH2 upstream signaling.
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Affiliation(s)
- Boheng Li
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Wee-Joo Chng
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore. .,Department of Haematology-Oncology, National University Cancer Institute of Singapore, Singapore, Singapore. .,Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
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6
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The interplay between Epstein-Bar virus (EBV) with the p53 and its homologs during EBV associated malignancies. Heliyon 2019; 5:e02624. [PMID: 31840114 PMCID: PMC6893087 DOI: 10.1016/j.heliyon.2019.e02624] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 07/26/2019] [Accepted: 10/08/2019] [Indexed: 12/12/2022] Open
Abstract
p53, p63, and p73, the members of the p53 family of proteins, are structurally similar proteins that play central roles regulating cell cycle and apoptotic cell death. Alternative splicing at the carboxyl terminus and the utilization of different promoters further categorizes these proteins as having different isoforms for each. Among such isoforms, TA and ΔN versions of each protein serve as the pro and the anti-apoptotic proteins, respectively. Changes in the expression patterns of these isoforms are noted in many human cancers. Proteins of certain human herpesviruses, like Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV), interact with p53 family members and alter their expressions in many malignancies. Upon infections in the B cells and epithelial cells, EBV expresses different lytic or latent proteins during viral replication and latency respectively to preserve viral copy number, chromosomal integrity and viral persistence inside the host. In this review, we have surveyed and summarised the interactions of EBV gene products, known so far, with the p53 family proteins. The interactions between P53 and EBV oncoproteins are observed in stomach cancer, non-Hodgkin's lymphoma (NHL) of the head and neck, Nasopharyngeal Cancer (NPC), Gastric carcinoma (GC) and Burkitt's lymphoma (BL). EBV latent protein EBNA1, EBNA3C, LMP-1, and lytic proteins BZLF-1 can alter p53 expressions in many cancer cell lines. Interactions of p63 with EBNA-1, 2, 5, LMP-2A and BARF-1 have also been investigated in several cancers. Similarly, associations of p73 isoform with EBV latent proteins EBNA3C and LMP-1 have been reported. Methylation and single nucleotide polymorphisms in p53 have also been found to be correlated with EBV infection. Therefore, interactions and altered expression strategies of the isoforms of p53 family proteins in EBV associated cancers propose an important field for further molecular research.
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Interplay between the Epigenetic Enzyme Lysine (K)-Specific Demethylase 2B and Epstein-Barr Virus Infection. J Virol 2019; 93:JVI.00273-19. [PMID: 30996097 DOI: 10.1128/jvi.00273-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 04/04/2019] [Indexed: 02/08/2023] Open
Abstract
The histone modifier lysine (K)-specific demethylase 2B (KDM2B) plays a role in the differentiation of hematopoietic cells, and its expression appears to be deregulated in certain cancers of hematological and lymphoid origins. We have previously found that the KDM2B gene is differentially methylated in cell lines derived from Epstein-Barr virus (EBV)-associated endemic Burkitt lymphoma (eBL) compared with that in EBV-negative sporadic Burkitt lymphoma-derived cells. However, whether KDM2B plays a role in eBL development has not been previously investigated. Oncogenic viruses have been shown to hijack the host cell epigenome to complete their life cycle and to promote the transformation process by perturbing cell chromatin organization. Here, we investigated whether EBV alters KDM2B levels to enable its life cycle and promote B-cell transformation. We show that infection of B cells with EBV leads to downregulation of KDM2B levels. We also show that LMP1, one of the main EBV transforming proteins, induces increased DNMT1 recruitment to the KDM2B gene and augments its methylation. By altering KDM2B levels and performing chromatin immunoprecipitation in EBV-infected B cells, we show that KDM2B is recruited to the EBV gene promoters and inhibits their expression. Furthermore, forced KDM2B expression in immortalized B cells led to altered mRNA levels of some differentiation-related genes. Our data show that EBV deregulates KDM2B levels through an epigenetic mechanism and provide evidence for a role of KDM2B in regulating virus and host cell gene expression, warranting further investigations to assess the role of KDM2B in the process of EBV-mediated lymphomagenesis.IMPORTANCE In Africa, Epstein-Barr virus infection is associated with endemic Burkitt lymphoma, a pediatric cancer. The molecular events leading to its development are poorly understood compared with those leading to sporadic Burkitt lymphoma. In a previous study, by analyzing the DNA methylation changes in endemic compared with sporadic Burkitt lymphoma cell lines, we identified several differential methylated genomic positions in the proximity of genes with a potential role in cancer, and among them was the KDM2B gene. KDM2B encodes a histone H3 demethylase already shown to be involved in some hematological disorders. However, whether KDM2B plays a role in the development of Epstein-Barr virus-mediated lymphoma has not been investigated before. In this study, we show that Epstein-Barr virus deregulates KDM2B expression and describe the underlying mechanisms. We also reveal a role of the demethylase in controlling viral and B-cell gene expression, thus highlighting a novel interaction between the virus and the cellular epigenome.
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Lang F, Pei Y, Lamplugh ZL, Robertson ES. Molecular Biology of EBV in Relationship to HIV/AIDS-Associated Oncogenesis. Cancer Treat Res 2019; 177:81-103. [PMID: 30523622 DOI: 10.1007/978-3-030-03502-0_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Herpesvirus-induced disease is one of the most lethal factors which leads to high mortality in HIV/AIDS patients. EBV, also known as human herpesvirus 4, can transform naive B cells into immortalized cells in vitro through the regulation of cell cycle, cell proliferation, and apoptosis. EBV infection is associated with several lymphoma and epithelial cancers in humans, which occurs at a much higher rate in immune deficient individuals than in healthy people, demonstrating that the immune system plays a vital role in inhibiting EBV activities. EBV latency infection proteins can mimic suppression cytokines or upregulate PD-1 on B cells to repress the cytotoxic T cells response. Many malignancies, including Hodgkin Lymphoma and non-Hodgkin's lymphomas occur at a much higher frequency in EBV positive individuals than in EBV negative people during the development of HIV infection. Importantly, understanding EBV pathogenesis at the molecular level will aid the development of novel therapies for EBV-induced diseases in HIV/AIDS patients.
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Affiliation(s)
- Fengchao Lang
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology and Global Cancer Programs, Abramson Cancer Center, Philadelphia, USA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Yonggang Pei
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology and Global Cancer Programs, Abramson Cancer Center, Philadelphia, USA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Zachary L Lamplugh
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology and Global Cancer Programs, Abramson Cancer Center, Philadelphia, USA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Erle S Robertson
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology and Global Cancer Programs, Abramson Cancer Center, Philadelphia, USA. .,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA. .,, 3610 Hamilton Walk, 201E Johnson Pavilion, Philadelphia, PA, 19104, USA.
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9
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EBV and KSHV Infection Dysregulates Autophagy to Optimize Viral Replication, Prevent Immune Recognition and Promote Tumorigenesis. Viruses 2018; 10:v10110599. [PMID: 30384495 PMCID: PMC6266050 DOI: 10.3390/v10110599] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/22/2018] [Accepted: 10/30/2018] [Indexed: 12/12/2022] Open
Abstract
Autophagy is a catabolic process strongly involved in the immune response, and its dysregulation contributes to the onset of several diseases including cancer. The human oncogenic gammaherpesviruses, Epstein—Barr virus (EBV) and Kaposi’s sarcoma-associated herpesvirus (KSHV), manipulate autophagy, either during the de novo infection or during the lytic reactivation, in naturally latently-infected lymphoma cells. In particular, the gammaherpesvirus infection reduces autophagy in immune cells, such as monocytes, resulting in the impairment of cell survival and cell differentiation into dendritic cells (DCs), which are essential for initiating and regulating the immune response. In the case of EBV, the reduction of autophagy in these cells, leading to p62 accumulation, activated the p62-NRF2-antioxidant response, reducing ROS, and further inhibiting autophagy. KSHV inhibits autophagy in monocytes by de-phosphorylating JNK2, altering the calpains–calpastatin balance and increasing the calpain activity responsible for the cleavage of ATG5. To further impair the immune response, KSHV also inhibits autophagy in differentiated DCs by hyper-phosphorylating STAT3. Conversely, when the lytic cycle is induced in vitro in latently-infected lymphoma B cells, both EBV and KSHV promote autophagy to enhance their replication, although the final autophagic steps are blocked through the down-regulation of Rab7. This strategy allows viruses to avoid the destructive environment of lysosomes, and to exploit the autophagic machinery for intracellular transportation. EBV and KSHV encode for proteins that may either inhibit or promote autophagy and, in addition, they can modulate the cellular pathways that control this process. In this review we will discuss the findings that indicate that autophagy is dysregulated by gammaherpesvirus to promote immune suppression, facilitate viral replication and contribute to the onset and maintenance of gammaherpesvirus-associated malignancies.
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10
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Hu B, Huo Y, Yang L, Chen G, Luo M, Yang J, Zhou J. ZIKV infection effects changes in gene splicing, isoform composition and lncRNA expression in human neural progenitor cells. Virol J 2017; 14:217. [PMID: 29116029 PMCID: PMC5688814 DOI: 10.1186/s12985-017-0882-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 10/30/2017] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND The Zika virus (ZIKV) is a mosquito-borne flavivirus that causes microcephaly and Guillain-Barré syndrome in infected individuals. To obtain insights into the mechanism of ZIKV infection and pathogenesis, we analyzed the transcriptome of ZIKV infected human neural progenitor cells (hNPCs) for changes in alternative splicing (AS), gene isoform (ISO) composition and long noncoding RNAs (lncRNAs) expression. METHODS We analyzed differentially expressed lncRNAs, AS, ISO from RNA-seq data in ZIKV infected hNPCs. RESULTS We obtained 149 differentially expressed lncRNAs, including potential viral targets to modulate cellular processes such as cell cycle, apoptosis and immune response. The infection induced 262 cases of AS occurring in 229 genes, which were enriched in cell death, RNA processing, transport, and neuron development. Among 691 differentially expressed ISOs, upregulated ISOs were enriched in signaling, regulation of transcription, and amino acid biosynthesis, while downregulated ISOs were mostly enriched in cell cycle. Importantly, these analyses revealed specific links between ZIKV induced changes in cellular pathways and the type of changes in the host transcriptome, suggesting important regulatory mechanisms. CONCLUSIONS Our analyses revealed candidate lncRNAs, AS events and ISOs which may function in ZIKV infection induced cell cycle disruption, apoptosis and attenuation of neurogenesis, and shed light on the roles of lncRNAs, AS and ISOs in virus-host interactions, and would facilitate future studies of ZIKV infection and pathogenesis.
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Affiliation(s)
- Benxia Hu
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, 650223, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, China
| | - Yongxia Huo
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, 650223, China
| | - Liping Yang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, 650223, China
| | - Guijun Chen
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, 650223, China
| | - Minhua Luo
- State Key Laboratory of Virology, CAS Center for Excellence in Brain Science and Intelligence Technology (CEBSIT), Wuhan Institute of Virology, Wuhan, 430071, China
| | - Jinlong Yang
- BGI-Yunnan, BGI-Shenzhen, Kunming, 650000, China.,College of Life Sciences, Yunnan University, Kunming, 650091, China
| | - Jumin Zhou
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, 650223, China.
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Carrasco-Avino G, Riquelme I, Padilla O, Villaseca M, Aguayo FR, Corvalan AH. The conundrum of the Epstein-Barr virus-associated gastric carcinoma in the Americas. Oncotarget 2017; 8:75687-75698. [PMID: 29088902 PMCID: PMC5650457 DOI: 10.18632/oncotarget.18497] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 05/29/2017] [Indexed: 02/07/2023] Open
Abstract
Epstein-Barr virus-associated gastric carcinoma shows a higher prevalence in the Americas than Asia. We summarize all studies of Epstein Barr virus-associated gastric carcinoma in the Americas, focusing on host characteristics, environmental associations and phylogeographic diversity of Epstein-Barr virus strains. In the Americas, the prevalence of Epstein Barr virus-associated gastric carcinoma is 11.4%, more frequent in males and portray predominantly diffuse-type histology. EBERs, EBNAs, BARTs and LMP are the highest expressed genes; their variations in healthy individuals may explain the phylogeographic diversity of Epstein-Barr virus across the region. Gastric cancer cases harbor exclusively the western genotype (subtype D and kept Xho I site), suggesting a disrupted co-evolution between the pathogen and its host. Epstein-Barr virus-associated gastric carcinoma molecular subtype cases from The Cancer Genome Atlas display PIK3CA gene mutations, amplification of JAK2, PD-L1 and PD-L2 and CpG island methylator phenotype, leading to more extensive methylation of host and viral genomes than any other subtypes from the study. Environmental conditions include negative- and positive- associations with being firstborn child and smoking, respectively. A marginal association with H. pylori has also been reported. Lymphoepithelioma-like carcinoma is associated with Epstein Barr virus in 80%-86% of cases, most of which have been included as part of Epstein Barr virus-associated gastric carcinoma series (prevalence 1.1%-7.6%). Whether these cases represent a variant of Epstein-Barr virus-associated gastric carcinoma is discussed. We propose novel research strategies to solve the conundrum of the high prevalence of Epstein-Barr virus-associated gastric carcinoma in the Americas.
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Affiliation(s)
- Gonzalo Carrasco-Avino
- Advanced Center for Chronic Diseases (ACCDIS), Pontificia Universidad Catolica de Chile, Santiago, Chile
- Department of Pathology, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Ismael Riquelme
- Scientific and Technological Bioresource Nucleus (BIOREN), Universidad de la Frontera, Temuco, Chile
- Department of Pathology, Universidad de la Frontera, Temuco, Chile
| | - Oslando Padilla
- Department of Public Health, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Miguel Villaseca
- Department of Pathology, Universidad de la Frontera, Temuco, Chile
| | - Francisco R. Aguayo
- Advanced Center for Chronic Diseases (ACCDIS), Pontificia Universidad Catolica de Chile, Santiago, Chile
- Department of Basic and Clinical Oncology, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Alejandro H. Corvalan
- Advanced Center for Chronic Diseases (ACCDIS), Pontificia Universidad Catolica de Chile, Santiago, Chile
- UC-Center for Investigational Oncology (CITO), Pontificia Universidad Catolica de Chile, Santiago, Chile
- Department of Hematology and Oncology, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile
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12
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Martínez-Campos C, Burguete-García AI, Madrid-Marina V. Role of TLR9 in Oncogenic Virus-Produced Cancer. Viral Immunol 2017; 30:98-105. [DOI: 10.1089/vim.2016.0103] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Affiliation(s)
- Cecilia Martínez-Campos
- Dirección de Infecciones Crónicas y Cáncer, Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, Mexico
| | - Ana I. Burguete-García
- Dirección de Infecciones Crónicas y Cáncer, Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, Mexico
| | - Vicente Madrid-Marina
- Dirección de Infecciones Crónicas y Cáncer, Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, Mexico
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13
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Jha HC, Pei Y, Robertson ES. Epstein-Barr Virus: Diseases Linked to Infection and Transformation. Front Microbiol 2016; 7:1602. [PMID: 27826287 PMCID: PMC5078142 DOI: 10.3389/fmicb.2016.01602] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 09/26/2016] [Indexed: 12/16/2022] Open
Abstract
Epstein–Barr virus (EBV) was first discovered in 1964, and was the first known human tumor virus now shown to be associated with a vast number of human diseases. Numerous studies have been conducted to understand infection, propagation, and transformation in various cell types linked to human diseases. However, a comprehensive lens through which virus infection, reactivation and transformation of infected host cells can be visualized is yet to be formally established and will need much further investigation. Several human cell types infected by EBV have been linked to associated diseases. However, whether these are a direct result of EBV infection or indirectly due to contributions by additional infectious agents will need to be fully investigated. Therefore, a thorough examination of infection, reactivation, and cell transformation induced by EBV will provide a more detailed view of its contributions that drive pathogenesis. This undoubtedly expand our knowledge of the biology of EBV infection and the signaling activities of targeted cellular factors dysregulated on infection. Furthermore, these insights may lead to identification of therapeutic targets and agents for clinical interventions. Here, we review the spectrum of EBV-associated diseases, the role of the encoded latent antigens, and the switch to latency or lytic replication which occurs in EBV infected cells. Furthermore, we describe the cellular processes and critical factors which contribute to cell transformation. We also describe the fate of B-cells and epithelial cells after EBV infection and the expected consequences which contribute to establishment of viral-associated pathologies.
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Affiliation(s)
- Hem C Jha
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia PA, USA
| | - Yonggang Pei
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia PA, USA
| | - Erle S Robertson
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia PA, USA
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14
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Epstein-Barr Virus Oncoprotein LMP1 Mediates Epigenetic Changes in Host Gene Expression through PARP1. J Virol 2016; 90:8520-30. [PMID: 27440880 DOI: 10.1128/jvi.01180-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 07/11/2016] [Indexed: 12/14/2022] Open
Abstract
UNLABELLED The latent infection of Epstein-Barr virus (EBV) is associated with 1% of human cancer incidence. Poly(ADP-ribosyl)ation (PARylation) is a posttranslational modification catalyzed by poly(ADP-ribose) polymerases (PARPs) that mediate EBV replication during latency. In this study, we detail the mechanisms that drive cellular PARylation during latent EBV infection and the effects of PARylation on host gene expression and cellular function. EBV-infected B cells had higher PAR levels than EBV-negative B cells. Moreover, cellular PAR levels were up to 2-fold greater in type III than type I latently infected EBV B cells. We identified a positive association between expression of the EBV genome-encoded latency membrane protein 1 (LMP1) and PAR levels that was dependent upon PARP1. PARP1 regulates gene expression by numerous mechanisms, including modifying chromatin structure and altering the function of chromatin-modifying enzymes. Since LMP1 is essential in establishing EBV latency and promoting tumorigenesis, we explored the model that disruption in cellular PARylation, driven by LMP1 expression, subsequently promotes epigenetic alterations to elicit changes in host gene expression. PARP1 inhibition resulted in the accumulation of the repressive histone mark H3K27me3 at a subset of LMP1-regulated genes. Inhibition of PARP1, or abrogation of PARP1 expression, also suppressed the expression of LMP1-activated genes and LMP1-mediated cellular transformation, demonstrating an essential role for PARP1 activity in LMP1-induced gene expression and cellular transformation associated with LMP1. In summary, we identified a novel mechanism by which LMP1 drives expression of host tumor-promoting genes by blocking generation of the inhibitory histone modification H3K27me3 through PARP1 activation. IMPORTANCE EBV is causally linked to several malignancies and is responsible for 1% of cancer incidence worldwide. The EBV-encoded protein LMP1 is essential for promoting viral tumorigenesis by aberrant activation of several well-known intracellular signaling pathways. We have identified and defined an additional novel molecular mechanism by which LMP1 regulates the expression of tumor-promoting host genes. We found that LMP1 activates the cellular protein PARP1, leading to a decrease in a repressive histone modification, accompanied by induction in expression of multiple cancer-related genes. PARP1 inhibition or depletion led to a decrease in LMP1-induced cellular transformation. Therefore, targeting PARP1 activity may be an effective treatment for EBV-associated malignancies.
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Guo M, Wei J, Huang X, Zhou Y, Yan Y, Qin Q. JNK1 Derived from Orange-Spotted Grouper, Epinephelus coioides, Involving in the Evasion and Infection of Singapore Grouper Iridovirus (SGIV). Front Microbiol 2016; 7:121. [PMID: 26903999 PMCID: PMC4748057 DOI: 10.3389/fmicb.2016.00121] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 01/22/2015] [Indexed: 01/16/2023] Open
Abstract
c-Jun N-terminal kinase (JNK) regulates cellular responses to various extracellular stimuli, environmental stresses, pathogen infections, and apoptotic agents. Here, a JNK1, Ec-JNK1, was identified from orange-spotted grouper, Epinephelus coioides. Ec-JNK1 has been found involving in the immune response to pathogen challenges in vivo, and the infection of Singapore grouper iridovirus (SGIV) and SGIV-induced apoptosis in vitro. SGIV infection activated Ec-JNK1, of which phosphorylation of motif TPY is crucial for its activity. Over-expressing Ec-JNK1 phosphorylated transcription factors c-Jun and promoted the infection and replication of SGIV, while partial inhibition of the phosphorylation of Ec-JNK1 showed the opposite effects by over-expressing the dominant-negative EcJNK1-Δ183-185 mutant. Interestingly, SGIV enhanced the viral infectivity by activating Ec-JNK1 which in turn drastically inhibited the antiviral responses of type 1 IFN, indicating that Ec-JNK1 could be involved in blocking IFN signaling during SGIV infection. In addition, Ec-JNK1 enhanced the activation of AP-1, p53, and NF-κB, and resulted in increasing the levels of SGIV-induced cell death. The caspase 3-dependent activation correlated with the phosphorylation of Ec-JNK1 and contributed to SGIV-induced apoptosis. Taken together, SGIV modulated the phosphorylation of Ec-JNK1 to inactivate the antiviral signaling, enhance the SGIV-induced apoptosis and activate transcription factors for efficient infection and replication. The “positive cooperativity” molecular mechanism mediated by Ec-JNK1 contributes to the successful evasion and infection of iridovirus pathogenesis.
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Affiliation(s)
- Minglan Guo
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China
| | - Jingguang Wei
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China
| | - Xiaohong Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China
| | - Yongcan Zhou
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University Haikou, China
| | - Yang Yan
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China
| | - Qiwei Qin
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and TechnologyQingdao, China
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16
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Frecha C, Chevalier SA, van Uden P, Rubio I, Siouda M, Saidj D, Cohen C, Lomonte P, Accardi R, Tommasino M. Expression of the epidermodysplasia verruciformis-associated genes EVER1 and EVER2 is activated by exogenous DNA and inhibited by LMP1 oncoprotein from Epstein-Barr virus. J Virol 2015; 89:1461-7. [PMID: 25378492 PMCID: PMC4300658 DOI: 10.1128/jvi.02936-14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 10/29/2014] [Indexed: 12/31/2022] Open
Abstract
EVER1 and EVER2 are mutated in epidermodysplasia verruciformis patients, who are susceptible to human betapapillomavirus (HPV) infection. It is unknown whether their products control the infection of other viruses. Here, we show that the expression of both genes in B cells is activated immediately after Epstein-Barr virus (EBV) infection, whereas at later stages, it is strongly repressed via activation of the NF-κB signaling pathway by latent membrane protein 1 (LMP1). Ectopic expression of EVER1 impairs the ability of EBV to infect B cells.
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Affiliation(s)
- Cecilia Frecha
- Section of Infections, Infections and Cancer Biology Group, International Agency for Research on Cancer, Lyon, France
| | - Sébastien A Chevalier
- Section of Infections, Infections and Cancer Biology Group, International Agency for Research on Cancer, Lyon, France
| | - Patrick van Uden
- Section of Infections, Infections and Cancer Biology Group, International Agency for Research on Cancer, Lyon, France
| | - Ivonne Rubio
- Section of Infections, Infections and Cancer Biology Group, International Agency for Research on Cancer, Lyon, France
| | - Maha Siouda
- Section of Infections, Infections and Cancer Biology Group, International Agency for Research on Cancer, Lyon, France
| | - Djamel Saidj
- Section of Infections, Infections and Cancer Biology Group, International Agency for Research on Cancer, Lyon, France
| | - Camille Cohen
- Virus & Centromère Team, Centre de Génétique et Physiologie Moléculaire et Cellulaire, CNRS, UMR5534, Lyon, France Université de Lyon 1, Lyon, France Laboratoire d'Excellence, LabEX DEVweCAN, Lyon, France
| | - Patrick Lomonte
- Virus & Centromère Team, Centre de Génétique et Physiologie Moléculaire et Cellulaire, CNRS, UMR5534, Lyon, France Université de Lyon 1, Lyon, France Laboratoire d'Excellence, LabEX DEVweCAN, Lyon, France
| | - Rosita Accardi
- Section of Infections, Infections and Cancer Biology Group, International Agency for Research on Cancer, Lyon, France
| | - Massimo Tommasino
- Section of Infections, Infections and Cancer Biology Group, International Agency for Research on Cancer, Lyon, France
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Epstein-Barr virus down-regulates tumor suppressor DOK1 expression. PLoS Pathog 2014; 10:e1004125. [PMID: 24809689 PMCID: PMC4014463 DOI: 10.1371/journal.ppat.1004125] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 04/01/2014] [Indexed: 12/29/2022] Open
Abstract
The DOK1 tumor suppressor gene encodes an adapter protein that acts as a negative regulator of several signaling pathways. We have previously reported that DOK1 expression is up-regulated upon cellular stress, via the transcription factor E2F1, and down-regulated in a variety of human malignancies due to aberrant hypermethylation of its promoter. Here we show that Epstein Barr virus (EBV) infection of primary human B-cells leads to the down-regulation of DOK1 gene expression via the viral oncoprotein LMP1. LMP1 alone induces recruitment to the DOK1 promoter of at least two independent inhibitory complexes, one containing E2F1/pRB/DNMT1 and another containing at least EZH2. These events result in tri-methylation of histone H3 at lysine 27 (H3K27me3) of the DOK1 promoter and gene expression silencing. We also present evidence that the presence of additional EBV proteins leads to further repression of DOK1 expression with an additional mechanism. Indeed, EBV infection of B-cells induces DNA methylation at the DOK1 promoter region including the E2F1 responsive elements that, in turn, lose the ability to interact with E2F complexes. Treatment of EBV-infected B-cell-lines with the methyl-transferase inhibitor 5-aza-2′-deoxycytidine rescues DOK1 expression. In summary, our data show the deregulation of DOK1 gene expression by EBV and provide novel insights into the regulation of the DOK1 tumor suppressor in viral-related carcinogenesis. Many oncogenic viruses exhibit cellular transforming properties, often involving oncogenes activation and tumor suppressor genes inactivation. The DOK1 gene is a newly identified tumor suppressor gene with altered expression via hypermethylation of its promoter in a variety of human cancers, including head and neck, lung, gastric and others. In addition, a correlation has been reported between DOK1 aberrant hypermethylation and the presence of oncogenic viruses such as hepatitis B virus (HBV) in hepatocellular carcinoma (HCC) and Epstein-Barr virus (EBV) in Burkitt's lymphoma-derived cell lines. Here we demonstrate for the first time that EBV is directly involved in the inhibition of DOK1 expression in B-cells. We show that EBV leads to epigenetic repression of DOK1 through increased DNA methylation of its promoter and H3K27 tri-methylation. The LMP1 oncoprotein plays a key role in the repression of DOK1 expression. It promotes the formation and the recruitment to the DOK1 promoter of transcriptionally inhibitory complexes composed of E2F1/pRB/DNMT1 and of EZH2 which is part of the polycomb repressive complex 2. Interestingly, one or more additional EBV protein(s) cooperate(s) with LMP1 in inducing massive DNA methylation at the DOK1 promoter, leading to the loss of E2F1 complexes recruitment and even stronger repression of DOK1 expression.
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18
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Tommasino M. The human papillomavirus family and its role in carcinogenesis. Semin Cancer Biol 2013; 26:13-21. [PMID: 24316445 DOI: 10.1016/j.semcancer.2013.11.002] [Citation(s) in RCA: 255] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 11/22/2013] [Accepted: 11/27/2013] [Indexed: 01/17/2023]
Abstract
Human papillomaviruses (HPVs) are a family of small double-stranded DNA viruses that have a tropism for the epithelia of the genital and upper respiratory tracts and for the skin. Approximately 150 HPV types have been discovered so far, which are classified into several genera based on their DNA sequence. Approximately 15 high-risk mucosal HPV types are clearly associated with cervical cancer; HPV16 and HPV18 are the most carcinogenic since they are responsible for approximately 50% and 20% of all cervical cancers worldwide, respectively. It is now also clear that these viruses are linked to a subset of other genital cancers, as well as head and neck cancers. Due to their high level of carcinogenic activity, HPV16 and HPV18 are the most studied HPV types so far. Biological studies have highlighted the key roles in cellular transformation of the products of two viral early genes, E6 and E7. Many of the mechanisms of E6 and E7 in subverting the regulation of fundamental cellular events have been fully characterized, contributing not only to our knowledge of how the oncogenic viruses promote cancer development but also to our understanding of basic cell biology. Despite HPV research resulting in extraordinary achievements in the last four decades, significantly improving the screening and prophylaxis of HPV-induced lesions, additional research is necessary to characterize the biology and epidemiology of the vast number of HPV types that have been poorly investigated so far, with a final aim of clarifying their potential roles in other human diseases.
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Affiliation(s)
- Massimo Tommasino
- Infections and Cancer Biology Group, International Agency for Research on Cancer - World Health Organization, 150 Cours Albert-Thomas, 69372 Lyon cedex 08, France.
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Oncoprotein E7 from beta human papillomavirus 38 induces formation of an inhibitory complex for a subset of p53-regulated promoters. J Virol 2013; 87:12139-50. [PMID: 24006445 DOI: 10.1128/jvi.01047-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Our previous studies on cutaneous beta human papillomavirus 38 (HPV38) E6 and E7 oncoproteins highlighted a novel activity of IκB kinase beta (IKKβ) in the nucleus of human keratinocytes, where it phosphorylates and stabilizes ΔNp73α, an antagonist of p53/p73 functions. Here, we further characterize the role of the IKKβ nuclear form. We show that IKKβ nuclear translocation and ΔNp73α accumulation are mediated mainly by HPV38 E7 oncoprotein. Chromatin immunoprecipitation (ChIP)/Re-ChIP experiments showed that ΔNp73α and IKKβ are part, together with two epigenetic enzymes DNA methyltransferase 1 (DNMT1) and the enhancer of zeste homolog 2 (EZH2), of a transcriptional regulatory complex that inhibits the expression of some p53-regulated genes, such as PIG3. Recruitment to the PIG3 promoter of EZH2 and DNMT1 resulted in trimethylation of histone 3 on lysine 27 and in DNA methylation, respectively, both events associated with gene expression silencing. Decreases in the intracellular levels of HPV38 E7 or ΔNp73α strongly affected the recruitment of the inhibitory transcriptional complex to the PIG3 promoter, with consequent restoration of p53-regulated gene expression. Finally, the ΔNp73α/IKKβ/DNMT1/EZH2 complex appears to bind a subset of p53-regulated promoters. In fact, the complex is efficiently recruited to several promoters of genes encoding proteins involved in DNA repair and apoptosis, whereas it does not influence the expression of the prosurvival factor Survivin. In summary, our data show that HPV38 via E7 protein promotes the formation of a multiprotein complex that negatively regulates the expression of several p53-regulated genes.
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