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Rocchi A, Wollebo HS, Khalili K. Neurotropic Viruses as Acute and Insidious Drivers of Aging. Biomolecules 2025; 15:514. [PMID: 40305226 PMCID: PMC12025245 DOI: 10.3390/biom15040514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2025] [Revised: 03/24/2025] [Accepted: 03/28/2025] [Indexed: 05/02/2025] Open
Abstract
Aging is the result of various compounding stresses that gradually overcome the homeostatic regulation of the cell, resulting in irreversible damage. This manifests as many acute and chronic conditions, the most common of which are neurodegeneration and dementia. Epidemiological studies have shown significant, strong correlations between viral infection and neurodegenerative diseases. This review overlays the characteristics of viral pathogenesis with the hallmarks of aging to discuss how active and latent viruses contribute to aging. Through our contextualization of myriad basic science papers, we offer explanations for premature aging via viral induction of common stress response pathways. Viruses induce many stresses: dysregulated homeostasis by exogenous viral proteins and overwhelmed protein quality control mechanisms, DNA damage through direct integration and epigenetic manipulation, immune-mediated oxidative stress and immune exhaustion, and general energy theft that is amplified in an aging system. Overall, this highlights the long-term importance of vaccines and antivirals in addition to their acute benefits.
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Affiliation(s)
| | - Hassen S. Wollebo
- Center for Neurovirology and Gene Editing, Department of Microbiology, Immunology and Inflammation, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA;
| | - Kamel Khalili
- Center for Neurovirology and Gene Editing, Department of Microbiology, Immunology and Inflammation, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA;
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2
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Zhao B. Epstein-Barr Virus B Cell Growth Transformation: The Nuclear Events. Viruses 2023; 15:832. [PMID: 37112815 PMCID: PMC10146190 DOI: 10.3390/v15040832] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/13/2023] [Accepted: 03/17/2023] [Indexed: 03/29/2023] Open
Abstract
Epstein-Barr virus (EBV) is the first human DNA tumor virus identified from African Burkitt's lymphoma cells. EBV causes ~200,000 various cancers world-wide each year. EBV-associated cancers express latent EBV proteins, EBV nuclear antigens (EBNAs), and latent membrane proteins (LMPs). EBNA1 tethers EBV episomes to the chromosome during mitosis to ensure episomes are divided evenly between daughter cells. EBNA2 is the major EBV latency transcription activator. It activates the expression of other EBNAs and LMPs. It also activates MYC through enhancers 400-500 kb upstream to provide proliferation signals. EBNALP co-activates with EBNA2. EBNA3A/C represses CDKN2A to prevent senescence. LMP1 activates NF-κB to prevent apoptosis. The coordinated activity of EBV proteins in the nucleus allows efficient transformation of primary resting B lymphocytes into immortalized lymphoblastoid cell lines in vitro.
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Affiliation(s)
- Bo Zhao
- Department of Medicine, Division of Infectious Diseases, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA 02115, USA
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3
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Wang C, Liu X, Liang J, Narita Y, Ding W, Li D, Zhang L, Wang H, Leong MML, Hou I, Gerdt C, Jiang C, Zhong Q, Tang Z, Forney C, Kottyan L, Weirauch MT, Gewurz BE, Zeng MS, Jiang S, Teng M, Zhao B. A DNA tumor virus globally reprograms host 3D genome architecture to achieve immortal growth. Nat Commun 2023; 14:1598. [PMID: 36949074 PMCID: PMC10033825 DOI: 10.1038/s41467-023-37347-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 03/13/2023] [Indexed: 03/24/2023] Open
Abstract
Epstein-Barr virus (EBV) immortalization of resting B lymphocytes (RBLs) to lymphoblastoid cell lines (LCLs) models human DNA tumor virus oncogenesis. RBL and LCL chromatin interaction maps are compared to identify the spatial and temporal genome architectural changes during EBV B cell transformation. EBV induces global genome reorganization where contact domains frequently merge or subdivide during transformation. Repressed B compartments in RBLs frequently switch to active A compartments in LCLs. LCLs gain 40% new contact domain boundaries. Newly gained LCL boundaries have strong CTCF binding at their borders while in RBLs, the same sites have much less CTCF binding. Some LCL CTCF sites also have EBV nuclear antigen (EBNA) leader protein EBNALP binding. LCLs have more local interactions than RBLs at LCL dependency factors and super-enhancer targets. RNA Pol II HiChIP and FISH of RBL and LCL further validate the Hi-C results. EBNA3A inactivation globally alters LCL genome interactions. EBNA3A inactivation reduces CTCF and RAD21 DNA binding. EBNA3C inactivation rewires the looping at the CDKN2A/B and AICDA loci. Disruption of a CTCF site at AICDA locus increases AICDA expression. These data suggest that EBV controls lymphocyte growth by globally reorganizing host genome architecture to facilitate the expression of key oncogenes.
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Affiliation(s)
- Chong Wang
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Xiang Liu
- Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, 33612, USA
| | - Jun Liang
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Yohei Narita
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Weiyue Ding
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Difei Li
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Luyao Zhang
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Hongbo Wang
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Merrin Man Long Leong
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Isabella Hou
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Catherine Gerdt
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Chang Jiang
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, 33612, USA
| | - Qian Zhong
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Zhonghui Tang
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510060, China
| | - Carmy Forney
- Center for Autoimmune Genomics and Etiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Leah Kottyan
- Center for Autoimmune Genomics and Etiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Matthew T Weirauch
- Center for Autoimmune Genomics and Etiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Benjamin E Gewurz
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Mu-Sheng Zeng
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Sizun Jiang
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02115, USA.
| | - Mingxiang Teng
- Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, 33612, USA.
| | - Bo Zhao
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA.
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4
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Wen KW, Wang L, Menke JR, Damania B. Cancers associated with human gammaherpesviruses. FEBS J 2022; 289:7631-7669. [PMID: 34536980 PMCID: PMC9019786 DOI: 10.1111/febs.16206] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 08/10/2021] [Accepted: 09/16/2021] [Indexed: 01/14/2023]
Abstract
Epstein-Barr virus (EBV; human herpesvirus 4; HHV-4) and Kaposi sarcoma-associated herpesvirus (KSHV; human herpesvirus 8; HHV-8) are human gammaherpesviruses that have oncogenic properties. EBV is a lymphocryptovirus, whereas HHV-8/KSHV is a rhadinovirus. As lymphotropic viruses, EBV and KSHV are associated with several lymphoproliferative diseases or plasmacytic/plasmablastic neoplasms. Interestingly, these viruses can also infect epithelial cells causing carcinomas and, in the case of KSHV, endothelial cells, causing sarcoma. EBV is associated with Burkitt lymphoma, classic Hodgkin lymphoma, nasopharyngeal carcinoma, plasmablastic lymphoma, lymphomatoid granulomatosis, leiomyosarcoma, and subsets of diffuse large B-cell lymphoma, post-transplant lymphoproliferative disorder, and gastric carcinoma. KSHV is implicated in Kaposi sarcoma, primary effusion lymphoma, multicentric Castleman disease, and KSHV-positive diffuse large B-cell lymphoma. Pathogenesis by these two herpesviruses is intrinsically linked to viral proteins expressed during the lytic and latent lifecycles. This comprehensive review intends to provide an overview of the EBV and KSHV viral cycles, viral proteins that contribute to oncogenesis, and the current understanding of the pathogenesis and clinicopathology of their related neoplastic entities.
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Affiliation(s)
- Kwun Wah Wen
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94158
| | - Linlin Wang
- Department of Laboratory Medicine, University of California, San Francisco, CA 94158
| | - Joshua R. Menke
- Department of Pathology, Stanford University, Palo Alto, CA 94304
| | - Blossom Damania
- Department of Microbiology & Immunology & Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599
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5
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Lurain K, Ramaswami R, Yarchoan R. The role of viruses in HIV-associated lymphomas. Semin Hematol 2022; 59:183-191. [PMID: 36805886 PMCID: PMC9971650 DOI: 10.1053/j.seminhematol.2022.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 11/15/2022] [Accepted: 11/26/2022] [Indexed: 12/03/2022]
Abstract
Lymphomas are among the most common cancers in people with HIV (PWH). The lymphoma subtypes and pathogenesis of lymphoma in PWH are different from the immunocompetent population. It is well-known that HIV causes severe CD4+ T cell lymphopenia in the absence of antiretroviral therapy (ART); however, the risk of developing certain subtypes of lymphoma remains elevated even in people receiving ART with preserved CD4+ T cells. HIV contributes to lymphomagenesis and causes decreased immune surveillance via T cell depletion and dysregulation, B cell dysregulation, and the potential contribution of HIV-encoded proteins. The oncogenic gammaherpesviruses, Epstein-Barr virus (EBV) and Kaposi sarcoma herpesvirus (KSHV, also known as human herpesvirus 8), are the causative agents in the majority of HIV-associated lymphomas. HIV-associated T cell depletion and dysregulation allows EBV and KSHV to proliferate in infected B cells. Specific EBV- and KSHV-encoded proteins participate in B cell activation, and proliferation leading to B cell transformation. Understanding the distinct pathogenesis of HIV-associated lymphomas affords opportunities to develop therapies that specifically target these unique aspects and improve lymphoma outcomes in PWH. Agents being studied that target the specific roles of HIV, EBV, and KSHV in lymphomagenesis include immunotherapies, targeted agents, and cellular therapies.
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Affiliation(s)
- Kathryn Lurain
- HIV & AIDS Malignancy Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD.
| | - Ramya Ramaswami
- HIV & AIDS Malignancy Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD
| | - Robert Yarchoan
- HIV & AIDS Malignancy Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD
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6
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Pietropaolo V, Prezioso C, Moens U. Role of Virus-Induced Host Cell Epigenetic Changes in Cancer. Int J Mol Sci 2021; 22:ijms22158346. [PMID: 34361112 PMCID: PMC8346956 DOI: 10.3390/ijms22158346] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/30/2021] [Accepted: 08/02/2021] [Indexed: 12/12/2022] Open
Abstract
The tumor viruses human T-lymphotropic virus 1 (HTLV-1), hepatitis C virus (HCV), Merkel cell polyomavirus (MCPyV), high-risk human papillomaviruses (HR-HPVs), Epstein-Barr virus (EBV), Kaposi’s sarcoma-associated herpes virus (KSHV) and hepatitis B virus (HBV) account for approximately 15% of all human cancers. Although the oncoproteins of these tumor viruses display no sequence similarity to one another, they use the same mechanisms to convey cancer hallmarks on the infected cell. Perturbed gene expression is one of the underlying mechanisms to induce cancer hallmarks. Epigenetic processes, including DNA methylation, histone modification and chromatin remodeling, microRNA, long noncoding RNA, and circular RNA affect gene expression without introducing changes in the DNA sequence. Increasing evidence demonstrates that oncoviruses cause epigenetic modifications, which play a pivotal role in carcinogenesis. In this review, recent advances in the role of host cell epigenetic changes in virus-induced cancers are summarized.
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Affiliation(s)
- Valeria Pietropaolo
- Department of Public Health and Infectious Diseases, “Sapienza” University, 00185 Rome, Italy;
- Correspondence: (V.P.); (U.M.)
| | - Carla Prezioso
- Department of Public Health and Infectious Diseases, “Sapienza” University, 00185 Rome, Italy;
- IRCSS San Raffaele Roma, Microbiology of Chronic Neuro-Degenerative Pathologies, 00161 Rome, Italy
| | - Ugo Moens
- Molecular Inflammation Research Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø—The Arctic University of Norway, 9037 Tromsø, Norway
- Correspondence: (V.P.); (U.M.)
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7
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Transcription Repressor Protein ZBTB25 Associates with HDAC1-Sin3a Complex in Mycobacterium tuberculosis-Infected Macrophages, and Its Inhibition Clears Pathogen by Autophagy. mSphere 2021; 6:6/1/e00036-21. [PMID: 33627504 PMCID: PMC8544881 DOI: 10.1128/msphere.00036-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Downregulation of host gene expression is a key strategy employed by intracellular pathogens for their survival in macrophages and subsequent pathogenesis. In a previous study, we have shown that histone deacetylase 1 (HDAC1) levels go up in macrophages infected with Mycobacterium tuberculosis, and it hypoacetylates histone H3 at the promoter of IL-12B gene, leading to its downregulation. We now show that after infection with M. tuberculosis, HDAC1 is phosphorylated, and the levels of phosphorylated HDAC1 (pHDAC1) increase significantly in macrophages. We found that transcriptional repressor protein zinc finger and BTB domain 25 (ZBTB25) and transcriptional corepressor Sin3a associate with the HDAC1 silencing complex, which is recruited to the promoter of IL-12B to downregulate its expression in infected macrophages. Knocking down of ZBTB25 enhanced release of IL-12p40 from infected macrophages. Inhibition of HDAC1 and ZBTB25 promoted colocalization of M. tuberculosis and LC3 (microtubule-associated protein 1A/1B-light chain 3) in autophagosomes. Induction of autophagy resulted in the killing of intracellular M. tuberculosis. Enhanced phosphorylation of JAK2 and STAT4 was observed in macrophages upon treatment with HDAC1 and ZBTB inhibitors, and inhibition of JAK2/STAT4 negated the killing of the intracellular pathogen, suggesting their role in the autophagy-mediated killing of intracellular M. tuberculosis. In view of the emergence of drug resistance in M. tuberculosis, host-directed therapy is an attractive alternative strategy to combat tuberculosis (TB). HDACs have been proposed to be host targets for TB treatment. Our study indicates that ZBTB25, a functional subunit of the HDAC1/Sin3a repressor complex involved in IL-12B suppression, could be an alternative target for host-directed anti-TB therapy. IMPORTANCE Following infection with M. tuberculosis, levels of HDAC1 go up in macrophages, and it is recruited to the promoter of IL-12B where it hypoacetylates histone H3, leading to the downregulation of the gene. Here, we show that host transcriptional repressor protein ZBTB25 and transcriptional corepressor Sin3a associate with HDAC1 in the silencing complex. Knocking down of ZBTB25 prevented the recruitment of the complex to the promoter and consequently enhanced the gene expression and the release of IL-12p40 from infected macrophages. Pharmacological inhibition of ZBTB25 in infected macrophages resulted in the induction of autophagy and killing of intracellular M. tuberculosis. Drug-resistant TB is a serious challenge to TB control programs all over the world which calls for finding alternative therapeutic methods. Host-directed therapy is gaining significant momentum in treating infectious diseases. We propose that ZBTB25 is a potential target for host-directed treatment of TB.
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8
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Liao Y, Lupiani B, Izumiya Y, Reddy SM. Marek's disease virus Meq oncoprotein interacts with chicken HDAC 1 and 2 and mediates their degradation via proteasome dependent pathway. Sci Rep 2021; 11:637. [PMID: 33437016 PMCID: PMC7803728 DOI: 10.1038/s41598-020-80792-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/28/2020] [Indexed: 12/02/2022] Open
Abstract
Marek's disease virus (MDV) encodes a basic-leucine zipper (BZIP) protein, Meq, which is considered the major MDV oncoprotein. It has been reported that the oncogenicity of Meq is associated with its interaction with C-terminal binding protein 1 (CtBP), which is also an interaction partner of Epstein-Barr virus encoded EBNA3A and EBNA3C oncoproteins. Since both EBNA3C and CtBP interact with histone deacetylase 1 (HDAC1) and HDAC2, we examined whether Meq shares this interaction with chicken HDAC1 (chHDAC1) and chHDAC2. Using confocal microscopy analysis, we show that Meq co-localizes with chHDAC1 and chHDAC2 in the nuclei of MDV lymphoblastoid tumor cells. In addition, immunoprecipitation assays demonstrate that Meq interacts with chHDAC1 and chHDAC2 in transfected cells and MDV lymphoblastoid tumor cells. Using deletion mutants, interaction domains were mapped to the N-terminal dimerization domain of chHDAC1 and chHDAC2, and the BZIP domain of Meq. Our results further demonstrate that this interaction mediates the degradation of chHDAC1 and chHDAC2 via the proteasome dependent pathway. In addition, our results show that Meq also induces the reduction of global ubiquitinated proteins through a proteasome dependent pathway. In conclusion, our results provide evidence that Meq interacts with chHDAC1 and chHDAC2, and induces their proteasome dependent degradation.
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Affiliation(s)
- Yifei Liao
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, MS4467, TAMU, College Station, TX, 77843, USA
| | - Blanca Lupiani
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, MS4467, TAMU, College Station, TX, 77843, USA
| | - Yoshihiro Izumiya
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Sanjay M Reddy
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, MS4467, TAMU, College Station, TX, 77843, USA.
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9
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Parmar N, Chandrakar P, Kar S. Leishmania donovani Subverts Host Immune Response by Epigenetic Reprogramming of Macrophage M(Lipopolysaccharides + IFN-γ)/M(IL-10) Polarization. THE JOURNAL OF IMMUNOLOGY 2020; 204:2762-2778. [DOI: 10.4049/jimmunol.1900251] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 03/16/2020] [Indexed: 01/19/2023]
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10
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Maloney EM, Busque VA, Hui ST, Toh J, Fernandez-Vina M, Krams SM, Esquivel CO, Martinez OM. Genomic variations in EBNA3C of EBV associate with posttransplant lymphoproliferative disorder. JCI Insight 2020; 5:131644. [PMID: 32213705 DOI: 10.1172/jci.insight.131644] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 02/26/2020] [Indexed: 01/22/2023] Open
Abstract
Epstein-Barr Virus (EBV) is a ubiquitous virus linked to a variety of lymphoid and epithelial malignancies. In solid organ and hematopoietic stem cell transplant recipients, EBV is causally associated with posttransplant lymphoproliferative disorder (PTLD), a group of heterogeneous lymphoid diseases. EBV+ B cell lymphomas that develop in the context of PTLD are generally attributed to the immunosuppression required to promote graft survival, but little is known regarding the role of EBV genome diversity in the development of malignancy. We deep-sequenced the EBV genome from the peripheral blood of 18 solid organ transplant recipients, including 6 PTLD patients. Sequences from 6 EBV+ spontaneous lymphoblastoid B cell lines (SLCL) were similarly analyzed. The EBV genome from PTLD patients had a significantly greater number of variations than EBV from transplant recipients without PTLD. Importantly, there were 15 nonsynonymous variations, including 8 in the latent cycle gene EBNA3C that were associated with the development of PTLD. One of the nonsynonymous variations in EBNA3C is located within a previously defined T cell epitope. These findings suggest that variations in the EBV genome can contribute to the pathogenesis of PTLD.
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Affiliation(s)
| | - Vincent A Busque
- Division of Abdominal Transplantation, Department of Surgery, and
| | - Sin Ting Hui
- Division of Abdominal Transplantation, Department of Surgery, and
| | | | - Marcelo Fernandez-Vina
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Sheri M Krams
- Stanford Immunology.,Division of Abdominal Transplantation, Department of Surgery, and
| | | | - Olivia M Martinez
- Stanford Immunology.,Division of Abdominal Transplantation, Department of Surgery, and
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11
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Mirzaei H, Ghorbani S, Khanizadeh S, Namdari H, Faghihloo E, Akbari A. Histone deacetylases in virus-associated cancers. Rev Med Virol 2019; 30:e2085. [PMID: 31743548 DOI: 10.1002/rmv.2085] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/31/2019] [Accepted: 09/03/2019] [Indexed: 12/24/2022]
Abstract
Oncogenic viruses are one of the most important causes of cancer worldwide. The pathogens contribute to the establishment of human malignancies by affecting various cellular events. Epigenetic mechanisms, such as histone modification methylation/demethylation, are one of the most critical events manipulated by oncogenic viruses to drive tumorigenesis. Histone modifications are mediated by histone acetylation and deacetylation, regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs), respectively. Dysregulation of HDACs activity affects viral tumorigenesis in several ways, such as manipulating tumor suppressor and viral gene expression. The present review aims to describe the vital interactions between both cancer-caused/associated viruses and the HDAC machinery, particularly by focusing on those viruses involved in gastrointestinal tumors, as some of the most common viral-mediated cancers.
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Affiliation(s)
- Habibollah Mirzaei
- Hepatitis Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran.,Department of Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Saeed Ghorbani
- Student Research Committee, Iran University of Medical Sciences, Tehran, Iran.,Department of Virology, Faculty of Medicine, Iran University of Medical Science, Tehran, Iran
| | - Sayyad Khanizadeh
- Hepatitis Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran.,Department of Virology, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Haideh Namdari
- Colorectal Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Ebrahim Faghihloo
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abolfazl Akbari
- Colorectal Research Center, Iran University of Medical Sciences, Tehran, Iran
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12
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Lang F, Singh RK, Pei Y, Zhang S, Sun K, Robertson ES. EBV epitranscriptome reprogramming by METTL14 is critical for viral-associated tumorigenesis. PLoS Pathog 2019; 15:e1007796. [PMID: 31226160 PMCID: PMC6588254 DOI: 10.1371/journal.ppat.1007796] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/28/2019] [Indexed: 01/07/2023] Open
Abstract
Epstein-Barr virus (EBV) is a ubiquitous oncogenic virus that induces many cancers. N6-Methyladenosine (m6A) modification regulates many cellular processes. We explored the role of m6A in EBV gene regulation and associated cancers. We have comprehensively defined m6A modification of EBV latent and lytic transcripts. Furthermore, m6A modification demonstrated a functional role in regulation of the stability of viral transcripts. The methyltransferase METTL14 was induced at the transcript and protein levels, and knock-down of METTL14 led to decreased expression of latent EBV transcripts. METTL14 was also significantly induced in EBV-positive tumors, promoted growth of EBV-transformed cells and tumors in Xenograft animal models. Mechanistically, the viral-encoded latent oncoprotein EBNA3C activated transcription of METTL14, and directly interacted with METTL14 to promote its stability. This demonstrated that EBV hijacks METTL14 to drive EBV-mediated tumorigenesis. METTL14 is now a new target for development of therapeutics for treatment of EBV-associated cancers.
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Affiliation(s)
- Fengchao Lang
- Departments of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Rajnish Kumar Singh
- Departments of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Yonggang Pei
- Departments of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Shengwei Zhang
- Departments of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kunfeng Sun
- Departments of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Erle S. Robertson
- Departments of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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Hui KF, Yiu SPT, Tam KP, Chiang AKS. Viral-Targeted Strategies Against EBV-Associated Lymphoproliferative Diseases. Front Oncol 2019; 9:81. [PMID: 30873380 PMCID: PMC6400835 DOI: 10.3389/fonc.2019.00081] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/29/2019] [Indexed: 12/14/2022] Open
Abstract
Epstein-Barr virus (EBV) is strongly associated with a spectrum of EBV-associated lymphoproliferative diseases (EBV-LPDs) ranging from post-transplant lymphoproliferative disorder, B cell lymphomas (e.g., endemic Burkitt lymphoma, Hodgkin lymphoma, and diffuse large B cell lymphoma) to NK or T cell lymphoma (e.g., nasal NK/T-cell lymphoma). The virus expresses a number of latent viral proteins which are able to manipulate cell cycle and cell death processes to promote survival of the tumor cells. Several FDA-approved drugs or novel compounds have been shown to induce killing of some of the EBV-LPDs by inhibiting the function of latent viral proteins or activating the viral lytic cycle from latency. Here, we aim to provide an overview on the mechanisms by which EBV employs to drive the pathogenesis of various EBV-LPDs and to maintain the survival of the tumor cells followed by a discussion on the development of viral-targeted strategies based on the understanding of the patho-mechanisms.
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Affiliation(s)
- Kwai Fung Hui
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong
| | - Stephanie Pei Tung Yiu
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong
| | - Kam Pui Tam
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong
| | - Alan Kwok Shing Chiang
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong.,Center for Nasopharyngeal Carcinoma Research, The University of Hong Kong, Hong Kong, Hong Kong
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14
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Zhang S, Pei Y, Lang F, Sun K, Singh RK, Lamplugh ZL, Saha A, Robertson ES. EBNA3C facilitates RASSF1A downregulation through ubiquitin-mediated degradation and promoter hypermethylation to drive B-cell proliferation. PLoS Pathog 2019; 15:e1007514. [PMID: 30615685 PMCID: PMC6336319 DOI: 10.1371/journal.ppat.1007514] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 01/17/2019] [Accepted: 12/08/2018] [Indexed: 12/15/2022] Open
Abstract
EBV latent antigen 3C (EBNA3C) is essential for EBV-induced primary B-cell transformation. Infection by EBV induces hypermethylation of a number of tumor suppressor genes, which contributes to the development of human cancers. The Ras association domain family isoform 1A (RASSF1A) is a cellular tumor suppressor, which regulates a broad range of cellular functions, including apoptosis, cell-cycle arrest, mitotic arrest, and migration. However, the expression of RASSF1A is lost in many human cancers by epigenetic silencing. In the present study, we showed that EBNA3C promoted B-cell transformation by specifically suppressing the expression of RASSF1A. EBNA3C directly interacted with RASSF1A and induced RASSF1A degradation via the ubiquitin-proteasome-dependent pathway. SCFSkp2, an E3-ubiquitin ligase, was recruited by EBNA3C to enhance RASSF1A degradation. Moreover, EBNA3C decreased the transcriptional activity of RASSF1A promoter by enhancing its methylation through EBNA3C-mediated modulation of DNMTs expression. EBNA3C also inhibited RASSF1A-mediated cell apoptosis, disrupted RASSF1A-mediated microtubule and chromosomal stability, and promoted cell proliferation by upregulating Cyclin D1 and Cyclin E expression. Our data provides new details, which sheds light on additional mechanisms by which EBNA3C can induce B-cell transformation. This will also facilitate the development of novel therapeutic approaches through targeting of the RASSF1A pathway.
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Affiliation(s)
- Shengwei Zhang
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Yonggang Pei
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Fengchao Lang
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kunfeng Sun
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Rajnish Kumar Singh
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Zachary L. Lamplugh
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Abhik Saha
- Department of Life Sciences, Presidency University, Kolkata, India
| | - Erle S. Robertson
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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15
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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: 0.7] [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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16
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Li L, Ma BBY, Chan ATC, Chan FKL, Murray P, Tao Q. Epstein-Barr Virus-Induced Epigenetic Pathogenesis of Viral-Associated Lymphoepithelioma-Like Carcinomas and Natural Killer/T-Cell Lymphomas. Pathogens 2018; 7:pathogens7030063. [PMID: 30022006 PMCID: PMC6161003 DOI: 10.3390/pathogens7030063] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 07/13/2018] [Accepted: 07/17/2018] [Indexed: 12/13/2022] Open
Abstract
Cancer genome studies of Epstein-Barr virus (EBV)-associated tumors, including lymphoepithelioma-like carcinomas (LELC) of nasopharyngeal (NPC), gastric (EBVaGC) and lung tissues, and natural killer (NK)/T-cell lymphoma (NKTCL), reveal a unique feature of genomic alterations with fewer gene mutations detected than other common cancers. It is known now that epigenetic alterations play a critical role in the pathogenesis of EBV-associated tumors. As an oncogenic virus, EBV establishes its latent and lytic infections in B-lymphoid and epithelial cells, utilizing hijacked cellular epigenetic machinery. EBV-encoded oncoproteins modulate cellular epigenetic machinery to reprogram viral and host epigenomes, especially in the early stage of infection, using host epigenetic regulators. The genome-wide epigenetic alterations further inactivate a series of tumor suppressor genes (TSG) and disrupt key cellular signaling pathways, contributing to EBV-associated cancer initiation and progression. Profiling of genome-wide CpG methylation changes (CpG methylome) have revealed a unique epigenotype of global high-grade methylation of TSGs in EBV-associated tumors. Here, we have summarized recent advances of epigenetic alterations in EBV-associated tumors (LELCs and NKTCL), highlighting the importance of epigenetic etiology in EBV-associated tumorigenesis. Epigenetic study of these EBV-associated tumors will discover valuable biomarkers for their early detection and prognosis prediction, and also develop effective epigenetic therapeutics for these cancers.
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Affiliation(s)
- Lili Li
- Cancer Epigenetics Laboratory, Department of Clinical Oncology, State Key Laboratory of Oncology in South China, Sir YK Pao Center for Cancer and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China.
| | - Brigette B Y Ma
- Cancer Epigenetics Laboratory, Department of Clinical Oncology, State Key Laboratory of Oncology in South China, Sir YK Pao Center for Cancer and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China.
| | - Anthony T C Chan
- Cancer Epigenetics Laboratory, Department of Clinical Oncology, State Key Laboratory of Oncology in South China, Sir YK Pao Center for Cancer and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China.
| | - Francis K L Chan
- Institute of Digestive Disease and State Key Laboratory of Digestive Diseases, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China.
| | - Paul Murray
- School of Cancer Sciences, University of Birmingham, Birmingham B15 2TT, UK.
| | - Qian Tao
- Cancer Epigenetics Laboratory, Department of Clinical Oncology, State Key Laboratory of Oncology in South China, Sir YK Pao Center for Cancer and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China.
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17
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Vázquez-Ulloa E, Lizano M, Sjöqvist M, Olmedo-Nieva L, Contreras-Paredes A. Deregulation of the Notch pathway as a common road in viral carcinogenesis. Rev Med Virol 2018; 28:e1988. [PMID: 29956408 DOI: 10.1002/rmv.1988] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 03/27/2018] [Accepted: 05/23/2018] [Indexed: 12/15/2022]
Abstract
The Notch pathway is a conserved signaling pathway and a form of direct cell-cell communication related to many biological processes during development and adulthood. Deregulation of the Notch pathway is involved in many diseases, including cancer. Almost 20% of all cancer cases have an infectious etiology, with viruses responsible for at least 1.5 million new cancer cases per year. Seven groups of viruses have been classified as oncogenic: hepatitis B and C viruses (HBV and HCV respectively), Epstein-Barr virus (EBV), Kaposi sarcoma-associated herpesvirus (KSHV), human T lymphotropic virus (HTLV-1), human papillomavirus (HPV), and Merkel cell polyomavirus (MCPyV). These viruses share the ability to manipulate a variety of cell pathways that are critical in proliferation and differentiation, leading to malignant transformation. Viral proteins interact directly or indirectly with different members of the Notch pathway, altering their normal function. This review focuses exclusively on the direct interactions of viral oncoproteins with Notch elements, providing a deeper understanding of the dual behavior of the Notch pathway as activator or suppressor of neoplasia in virus-related cancers.
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Affiliation(s)
- Elenaé Vázquez-Ulloa
- Programa de Maestría y Doctorado en Ciencias Bioquímicas, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, Mexico.,Tecnológico Nacional de México, Instituto Tecnológico de Gustavo A. Madero, Mexico City, Mexico
| | - Marcela Lizano
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología-Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Marika Sjöqvist
- Faculty of Science and Engineering, Biosciences, Åbo Akademi University, Turku, Finland
| | - Leslie Olmedo-Nieva
- Programa de Maestría y Doctorado en Ciencias Bioquímicas, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Adriana Contreras-Paredes
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología-Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
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18
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Transcriptional and epigenetic modulation of autophagy promotes EBV oncoprotein EBNA3C induced B-cell survival. Cell Death Dis 2018; 9:605. [PMID: 29789559 PMCID: PMC5964191 DOI: 10.1038/s41419-018-0668-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 03/26/2018] [Accepted: 04/23/2018] [Indexed: 11/09/2022]
Abstract
Epstein-Barr virus (EBV) oncoprotein EBNA3C is indispensable for primary B-cell transformation and maintenance of lymphoblastoid cells outgrowth. EBNA3C usurps two putative cellular pathways-cell-cycle and apoptosis, essentially through modulating ubiquitin-mediated protein-degradation or gene transcription. In cancer cells, these two pathways are interconnected with autophagy,-a survival-promoting catabolic network in which cytoplasmic material including mis/un-folded protein aggregates and damaged organelles along with intracellular pathogens are degraded and recycled in lysosomal compartments. Studies have shown that tumor viruses including EBV can manipulate autophagy as a survival strategy. Here, we demonstrate that EBNA3C elevates autophagy, which serves as a prerequisite for apoptotic inhibition and maintenance of cell growth. Using PCR based micro-array we show that EBNA3C globally accelerates autophagy gene transcription under growth limiting conditions. Reanalyzing the ENCODE ChIP-sequencing data (GSE52632 and GSE26386) followed by ChIP-PCR demonstrate that EBNA3C recruits several histone activation epigenetic marks (H3K4me1, H3K4me3, H3K9ac, and H3K27ac) for transcriptional activation of autophagy genes, notably ATG3, ATG5, and ATG7 responsible for autophagosome formation. Moreover, under growth limiting conditions EBNA3C further stimulates the autophagic response through upregulation of a number of tumor suppressor genes, notably cyclin-dependent kinase inhibitors-CDKN1B (p27Kip1) and CDKN2A (p16INK4a) and autophagy mediated cell-death modulators-DRAM1 and DAPK1. Together our data highlight a new role of an essential EBV oncoprotein in regulating autophagy cascade as a survival mechanism and offer novel-targets for potential therapeutic expansion against EBV induced B-cell lymphomas.
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19
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Hui KF, Yeung PL, Tam KP, Chiang AKS. Counteracting survival functions of EBNA3C in Epstein-Barr virus (EBV)-driven lymphoproliferative diseases by combination of SAHA and bortezomib. Oncotarget 2018; 9:25101-25114. [PMID: 29861856 PMCID: PMC5982749 DOI: 10.18632/oncotarget.25341] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 04/06/2018] [Indexed: 12/13/2022] Open
Abstract
Combination of suberoylanilide hydroxamic acid (SAHA) and bortezomib (SAHA/bortezomib) was shown to synergistically induce killing of lymphoblastoid cell lines (LCL) and Burkitt lymphoma (BL) of type III or Wp-restricted latency, both of which express EBNA3A, -3B and -3C proteins. We hypothesize that SAHA/bortezomib can counteract the survival functions conferred by the EBNA3 proteins. We tested the effect of SAHA/bortezomib on the survival of BL cell lines containing EBNA3A, -3B or -3C knockout EBV with or without the respective revertant EBNA3 genes. Isobologram analysis showed that SAHA/bortezomib induced significantly greater synergistic killing of EBNA3C-revertant cells when compared with EBNA3C-knockout cells. Such differential response was not observed in either EBNA3A or -3B revertant versus their knockout pairs. Interestingly, EBNA3C-knockout cells showed significant G2/M arrest whilst EBNA3C-revertant cells and LCLs escaped G2/M arrest induced by SAHA/bortezomib and became more susceptible to the induction of apoptosis. In parallel, SAHA/bortezomib induced stronger expression of p21WAF1 but weaker expression of p-cdc25c, an M-phase inducer phosphatase, in EBNA3C-expressing cells when compared with EBNA3C-knockout cells. SAHA/bortezomib also induced greater growth suppression of EBNA3C-expressing xenografts (EBNA3C-revertant and LCL) than that of EBNA3C-knockout xenografts in SCID mice. In conclusion, our data showed that SAHA/bortezomib could synergistically induce killing of BL and LCL through counteracting the survival functions of EBNA3C, providing a strong basis for clinical testing of this drug combination in patients with EBV-associated lymphoproliferative diseases.
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Affiliation(s)
- Kwai Fung Hui
- Department of Pediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong SAR, China
| | - Po Ling Yeung
- Department of Pediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong SAR, China
| | - Kam Pui Tam
- Department of Pediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong SAR, China
| | - Alan Kwok Shing Chiang
- Department of Pediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong SAR, China
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20
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The Cooperative Functions of the EBNA3 Proteins Are Central to EBV Persistence and Latency. Pathogens 2018; 7:pathogens7010031. [PMID: 29562595 PMCID: PMC5874757 DOI: 10.3390/pathogens7010031] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 02/26/2018] [Accepted: 03/07/2018] [Indexed: 02/04/2023] Open
Abstract
The Epstein–Barr nuclear antigen 3 (EBNA3) family of proteins, comprising EBNA3A, EBNA3B, and EBNA3C, play pivotal roles in the asymptomatic persistence and life-long latency of Epstein–Barr virus (EBV) in the worldwide human population. EBNA3-mediated transcriptional reprogramming of numerous host cell genes promotes in vitro B cell transformation and EBV persistence in vivo. Despite structural and sequence similarities, and evidence of substantial cooperative activity between the EBNA3 proteins, they perform quite different, often opposing functions. Both EBNA3A and EBNA3C are involved in the repression of important tumour suppressive pathways and are considered oncogenic. In contrast, EBNA3B exhibits tumour suppressive functions. This review focuses on how the EBNA3 proteins achieve the delicate balance required to support EBV persistence and latency, with emphasis on the contribution of the Allday laboratory to the field of EBNA3 biology.
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21
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Therapeutic Strategies against Epstein-Barr Virus-Associated Cancers Using Proteasome Inhibitors. Viruses 2017; 9:v9110352. [PMID: 29160853 PMCID: PMC5707559 DOI: 10.3390/v9110352] [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: 10/31/2017] [Revised: 11/17/2017] [Accepted: 11/20/2017] [Indexed: 12/15/2022] Open
Abstract
Epstein-Barr virus (EBV) is closely associated with several lymphomas (endemic Burkitt lymphoma, Hodgkin lymphoma and nasal NK/T-cell lymphoma) and epithelial cancers (nasopharyngeal carcinoma and gastric carcinoma). To maintain its persistence in the host cells, the virus manipulates the ubiquitin-proteasome system to regulate viral lytic reactivation, modify cell cycle checkpoints, prevent apoptosis and evade immune surveillance. In this review, we aim to provide an overview of the mechanisms by which the virus manipulates the ubiquitin-proteasome system in EBV-associated lymphoid and epithelial malignancies, to evaluate the efficacy of proteasome inhibitors on the treatment of these cancers and discuss potential novel viral-targeted treatment strategies against the EBV-associated cancers.
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22
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Chromatin reorganisation in Epstein-Barr virus-infected cells and its role in cancer development. Curr Opin Virol 2017; 26:149-155. [DOI: 10.1016/j.coviro.2017.08.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 08/07/2017] [Accepted: 08/17/2017] [Indexed: 11/23/2022]
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23
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West MJ, Farrell PJ. Roles of RUNX in B Cell Immortalisation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 962:283-298. [PMID: 28299664 DOI: 10.1007/978-981-10-3233-2_18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
RUNX1 and RUNX3 are the main RUNX genes expressed in B lymphocytes. Both are expressed throughout B-cell development and play key roles at certain key developmental transitions. The tumour-associated Epstein-Barr virus (EBV) has potent B-cell transforming ability and manipulates RUNX3 and RUNX1 transcription through novel mechanisms to control B cell growth. In contrast to resting mature B cells where RUNX1 expression is high, in EBV-infected cells RUNX1 levels are low and RUNX3 levels are high. Downregulation of RUNX1 in these cells results from cross-regulation by RUNX3 and serves to relieve RUNX1-mediated growth repression. RUNX3 is upregulated by the EBV transcription factor (TF) EBNA2 and represses RUNX1 transcription through RUNX sites in the RUNX1 P1 promoter. Recent analysis revealed that EBNA2 activates RUNX3 transcription through an 18 kb upstream super-enhancer in a manner dependent on the EBNA2 and Notch DNA-binding partner RBP-J. This super-enhancer also directs RUNX3 activation by two further RBP-J-associated EBV TFs, EBNA3B and 3C. Counter-intuitively, EBNA2 also hijacks RBP-J to target a super-enhancer region upstream of RUNX1 to maintain some RUNX1 expression in certain cell backgrounds, although the dual functioning EBNA3B and 3C proteins limit this activation. Interestingly, the B-cell genome binding sites of EBV TFs overlap extensively with RUNX3 binding sites and show enrichment for RUNX motifs. Therefore in addition to B-cell growth manipulation through the long-range control of RUNX transcription, EBV may also use RUNX proteins as co-factors to deregulate the transcription of many B cell genes during immortalisation.
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Affiliation(s)
- Michelle J West
- School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK.
| | - Paul J Farrell
- Section of Virology, Faculty of Medicine, Imperial College London, Norfolk Place, London, W2 1PG, UK
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24
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Epigenetic Impact on EBV Associated B-Cell Lymphomagenesis. Biomolecules 2016; 6:biom6040046. [PMID: 27886133 PMCID: PMC5197956 DOI: 10.3390/biom6040046] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 11/02/2016] [Accepted: 11/07/2016] [Indexed: 01/09/2023] Open
Abstract
Epigenetic modifications leading to either transcriptional repression or activation, play an indispensable role in the development of human cancers. Epidemiological study revealed that approximately 20% of all human cancers are associated with tumor viruses. Epstein-Barr virus (EBV), the first human tumor virus, demonstrates frequent epigenetic alterations on both viral and host genomes in associated cancers—both of epithelial and lymphoid origin. The cell type-dependent different EBV latent gene expression patterns appear to be determined by the cellular epigenetic machinery and similarly viral oncoproteins recruit epigenetic regulators in order to deregulate the cellular gene expression profile resulting in several human cancers. This review elucidates the epigenetic consequences of EBV–host interactions during development of multiple EBV-induced B-cell lymphomas, which may lead to the discovery of novel therapeutic interventions against EBV-associated B-cell lymphomas by alteration of reversible patho-epigenetic markings.
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25
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Pei Y, Banerjee S, Sun Z, Jha HC, Saha A, Robertson ES. EBV Nuclear Antigen 3C Mediates Regulation of E2F6 to Inhibit E2F1 Transcription and Promote Cell Proliferation. PLoS Pathog 2016; 12:e1005844. [PMID: 27548379 PMCID: PMC4993364 DOI: 10.1371/journal.ppat.1005844] [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] [Received: 04/13/2016] [Accepted: 08/05/2016] [Indexed: 12/15/2022] Open
Abstract
Epstein–Barr virus (EBV) is considered a ubiquitous herpesvirus with the ability to cause latent infection in humans worldwide. EBV-association is evidently linked to different types of human malignancies, mainly of epithelial and lymphoid origin. Of interest is the EBV nuclear antigen 3C (EBNA3C) which is critical for EBV-mediated immortalization. Recently, EBNA3C was shown to bind the E2F1 transcription regulator. The E2F transcription factors have crucial roles in various cellular functions, including cell cycle, DNA replication, DNA repair, cell mitosis, and cell fate. Specifically, E2F6, one of the unique E2F family members, is known to be a pRb-independent transcription repressor of E2F-target genes. In our current study, we explore the role of EBNA3C in regulating E2F6 activities. We observed that EBNA3C plays an important role in inducing E2F6 expression in LCLs. Our study also shows that EBNA3C physically interacts with E2F6 at its amino and carboxy terminal domains and they form a protein complex in human cells. In addition, EBNA3C stabilizes the E2F6 protein and is co-localized in the nucleus. We also demonstrated that both EBNA3C and E2F6 contribute to reduction in E2F1 transcriptional activity. Moreover, E2F1 forms a protein complex with EBNA3C and E2F6, and EBNA3C competes with E2F1 for E2F6 binding. E2F6 is also recruited by EBNA3C to the E2F1 promoter, which is critical for EBNA3C-mediated cell proliferation. These results demonstrate a critical role for E2F family members in EBV-induced malignancies, and provide new insights for targeting E2F transcription factors in EBV-associated cancers as potential therapeutic intervention strategies. EBV is associated with a broad range of human cancers. EBV-encoded nuclear antigen 3C (EBNA3C) is one of the essential latent antigens important for deregulating the functions of numerous host transcription factors which play vital roles in B-cell immortalization. The family of E2F transcription factors are involved in diverse cellular functions. More specifically, E2F6 is one of the E2F family members with a unique property of transcriptional repression. Our current study now demonstrates that EBNA3C can enhance E2F6 repressive functions, and is also responsible for increased E2F6 protein expression in EBV-transformed LCLs. EBNA3C directly interacts with E2F6 at its amino and carboxy terminal domains. Additionally, E2F6 was stabilized by EBNA3C and co-localized in nuclear compartments. Our study also demonstrated that EBNA3C and E2F6 expression resulted in decreased transcriptional activity of E2F1, and that EBNA3C, E2F6 and E2F1 can form a protein complex, and EBNA3C competes with E2F1 for E2F6 binding. The recruitment of E2F6 by EBNA3C was also shown to be important for its related cell proliferation. These results showed a crucial role for EBNA3C-mediated deregulation of E2F6 and its impact on the activities of other E2F family members. Our findings also provide new insights for targeting these E2F transcription factors as potential therapeutic intervention strategies in EBV-associated cancers.
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Affiliation(s)
- Yonggang Pei
- Department of Otorhinolaryngology-Head and Neck Surgery, and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Shuvomoy Banerjee
- Department of Otorhinolaryngology-Head and Neck Surgery, and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Zhiguo Sun
- Department of Otorhinolaryngology-Head and Neck Surgery, and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Hem Chandra Jha
- Department of Otorhinolaryngology-Head and Neck Surgery, and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Abhik Saha
- Department of Biological Sciences, Presidency University, Kolkata, India
| | - Erle S Robertson
- Department of Otorhinolaryngology-Head and Neck Surgery, and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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Jha HC, Shukla SK, Lu J, Aj MP, Banerjee S, Robertson ES. Dissecting the contribution of EBNA3C domains important for EBV-induced B-cell growth and proliferation. Oncotarget 2016; 6:30115-29. [PMID: 26336822 PMCID: PMC4745785 DOI: 10.18632/oncotarget.5002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 08/07/2015] [Indexed: 12/21/2022] Open
Abstract
Epstein-Barr virus (EBV) is an oncogenic gammaherpes virus which is linked to pathogenesis of several human lymphatic malignancies. The EBV essential latent antigen EBNA3C is critical for efficient conversion of primary human B-lymphocytes to lymphoblastic cell lines and for continued LCL growth. EBNA3C, an EBV latent antigen with oncogenic potential can bind and regulate the functions of a wide range of cellular transcription factors. In our current reverse genetics study, we deleted the full length EBNA3C, and independently the RBP-Jκ and Nm23-H1 binding sites within EBNA3C using BACmid recombinant engineering methodology. Our experiments demonstrated that deletion of the EBV EBNA3C open reading frame (ORF) and more specifically the residues 621–675 which binds Nm23H1 and SUMO-1 showed a significant reduction in the ability of the cells to proliferate. Furthermore, they exhibited lower infectivity of human peripheral blood mononuclear cells (PBMCs). We also showed that recombinant EBV with deletions of the EBNA3C ORF, as well as a recombinant with residues 621–675 within EBNA3C ORF deleted had diminished abilities to activate CD40. Our study also revealed that the full length (1–992) and 621–675 aa deletions of EBNA3C when compared to wild type EBV infected PBMCs had differential expression patterns for the phosphorylation of MAP kinases specifically p38, JNK and ERK. Regulation of β-catenin also differed among wild type and EBNA3C deleted mutants. These temporal differences in signaling activities of these recombinant viruses in PBMCs is likely important in defining their functional importance in EBV-mediated B-cell transformation.
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Affiliation(s)
- Hem Chandra Jha
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, United States of America
| | - Sanket Kumar Shukla
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, United States of America
| | - Jie Lu
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, United States of America
| | - Mahadesh Prasad Aj
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, United States of America
| | - Shuvomoy Banerjee
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, United States of America
| | - Erle S Robertson
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, United States of America
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Bhattacharjee S, Ghosh Roy S, Bose P, Saha A. Role of EBNA-3 Family Proteins in EBV Associated B-cell Lymphomagenesis. Front Microbiol 2016; 7:457. [PMID: 27092119 PMCID: PMC4824013 DOI: 10.3389/fmicb.2016.00457] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 03/21/2016] [Indexed: 12/28/2022] Open
Abstract
Epstein-Barr virus (EBV) is highly ubiquitous in human population and establishes a lifelong asymptomatic infection within the infected host unless the immune system is compromised. Following initial infection in the oropharyngeal epithelial cells, EBV primarily infects naive B-lymphocytes and develops a number of B-cell lymphomas particularly in immune-deficient individuals. In vitro, EBV can also infect and subsequently transform quiescent B-lymphocytes into continuously proliferating lymphoblastoid cell lines (LCLs) resembling EBV-induced lymphoproliferative disorders in which a subset of latent transcripts are detected. Genetic studies revealed that EBNA-3 family comprising of three adjacent genes in the viral genome-EBNA-3A and -3C, but not -3B, are critical for B-cell transformation. Nevertheless, all three proteins appear to significantly contribute to maintain the overall proliferation and viability of transformed cells, suggesting a critical role in lymphoma development. Apart from functioning as important viral transcriptional regulators, EBNA-3 proteins associate with many cellular proteins in different signaling networks, providing a suitable platform for lifelong survival of the virus and concurrent lymphoma development in the infected host. The chapter describes the function of each these EBV nuclear antigen 3 proteins employed by the virus as a means to understand viral pathogenesis of several EBV-associated B-cell malignancies.
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Affiliation(s)
| | | | - Priyanka Bose
- Department of Biological Sciences, Presidency University Kolkata, India
| | - Abhik Saha
- Department of Biological Sciences, Presidency University Kolkata, India
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EBNA3C regulates p53 through induction of Aurora kinase B. Oncotarget 2016; 6:5788-803. [PMID: 25691063 PMCID: PMC4467402 DOI: 10.18632/oncotarget.3310] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 01/02/2015] [Indexed: 01/08/2023] Open
Abstract
In multicellular organisms p53 maintains genomic integrity through activation of DNA repair, and apoptosis. EBNA3C can down regulate p53 transcriptional activity. Aurora kinase (AK) B phosphorylates p53, which leads to degradation of p53. Aberrant expression of AK-B is a hallmark of numerous human cancers. Therefore changes in the activities of p53 due to AK-B and EBNA3C expression is important for understanding EBV-mediated cell transformation. Here we show that the activities of p53 and its homolog p73 are dysregulated in EBV infected primary cells which can contribute to increased cell transformation. Further, we showed that the ETS-1 binding site is crucial for EBNA3C-mediated up-regulation of AK-B transcription. Further, we determined the Ser 215 residue of p53 is critical for functional regulation by AK-B and EBNA3C and that the kinase domain of AK-B which includes amino acid residues 106, 111 and 205 was important for p53 regulation. AK-B with a mutation at residue 207 was functionally similar to wild type AK-B in terms of its kinase activities and knockdown of AK-B led to enhanced p73 expression independent of p53. This study explores an additional mechanism by which p53 is regulated by AK-B and EBNA3C contributing to EBV-induced B-cell transformation.
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Jha HC, Banerjee S, Robertson ES. The Role of Gammaherpesviruses in Cancer Pathogenesis. Pathogens 2016; 5:pathogens5010018. [PMID: 26861404 PMCID: PMC4810139 DOI: 10.3390/pathogens5010018] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 01/27/2016] [Indexed: 12/15/2022] Open
Abstract
Worldwide, one fifth of cancers in the population are associated with viral infections. Among them, gammaherpesvirus, specifically HHV4 (EBV) and HHV8 (KSHV), are two oncogenic viral agents associated with a large number of human malignancies. In this review, we summarize the current understanding of the molecular mechanisms related to EBV and KSHV infection and their ability to induce cellular transformation. We describe their strategies for manipulating major cellular systems through the utilization of cell cycle, apoptosis, immune modulation, epigenetic modification, and altered signal transduction pathways, including NF-kB, Notch, Wnt, MAPK, TLR, etc. We also discuss the important EBV latent antigens, namely EBNA1, EBNA2, EBNA3’s and LMP’s, which are important for targeting these major cellular pathways. KSHV infection progresses through the engagement of the activities of the major latent proteins LANA, v-FLIP and v-Cyclin, and the lytic replication and transcription activator (RTA). This review is a current, comprehensive approach that describes an in-depth understanding of gammaherpes viral encoded gene manipulation of the host system through targeting important biological processes in viral-associated cancers.
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Affiliation(s)
- Hem Chandra Jha
- Department of Microbiology and Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 201E Johnson Pavilion, 3610, Hamilton Walk, Philadelphia, PA 19104, USA.
| | - Shuvomoy Banerjee
- Department of Microbiology and Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 201E Johnson Pavilion, 3610, Hamilton Walk, Philadelphia, PA 19104, USA.
| | - Erle S Robertson
- Department of Microbiology and Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 201E Johnson Pavilion, 3610, Hamilton Walk, Philadelphia, PA 19104, USA.
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EBNA3C Directs Recruitment of RBPJ (CBF1) to Chromatin during the Process of Gene Repression in EBV Infected B Cells. PLoS Pathog 2016; 12:e1005383. [PMID: 26751214 PMCID: PMC4708995 DOI: 10.1371/journal.ppat.1005383] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 12/14/2015] [Indexed: 12/05/2022] Open
Abstract
It is well established that Epstein-Barr virus nuclear antigen 3C (EBNA3C) can act as a potent repressor of gene expression, but little is known about the sequence of events occurring during the repression process. To explore further the role of EBNA3C in gene repression–particularly in relation to histone modifications and cell factors involved–the three host genes previously reported as most robustly repressed by EBNA3C were investigated. COBLL1, a gene of unknown function, is regulated by EBNA3C alone and the two co-regulated disintegrin/metalloproteases, ADAM28 and ADAMDEC1 have been described previously as targets of both EBNA3A and EBNA3C. For the first time, EBNA3C was here shown to be the main regulator of all three genes early after infection of primary B cells. Using various EBV-recombinants, repression over orders of magnitude was seen only when EBNA3C was expressed. Unexpectedly, full repression was not achieved until 30 days after infection. This was accurately reproduced in established LCLs carrying EBV-recombinants conditional for EBNA3C function, demonstrating the utility of the conditional system to replicate events early after infection. Using this system, detailed chromatin immunoprecipitation analysis revealed that the initial repression was associated with loss of activation-associated histone modifications (H3K9ac, H3K27ac and H3K4me3) and was independent of recruitment of polycomb proteins and deposition of the repressive H3K27me3 modification, which were only observed later in repression. Most remarkable, and in contrast to current models of RBPJ in repression, was the observation that this DNA-binding factor accumulated at the EBNA3C-binding sites only when EBNA3C was functional. Transient reporter assays indicated that repression of these genes was dependent on the interaction between EBNA3C and RBPJ. This was confirmed with a novel EBV-recombinant encoding a mutant of EBNA3C unable to bind RBPJ, by showing this virus was incapable of repressing COBLL1 or ADAM28/ADAMDEC1 in newly infected primary B cells. The Epstein-Barr nuclear protein EBNA3C is a well-characterised repressor of host gene expression in B cells growth-transformed by EBV. It is also well established that EBNA3C can interact with the cellular factor RBPJ, a DNA-binding factor in the Notch signalling pathway conserved from worms to humans. However, prior to this study, little was known about the role of the interaction between these two proteins during the repression of host genes. We therefore chose three genes–the expression of which is very robustly repressed by EBNA3C –to explore the molecular interactions involved. Hitherto these genes had not been shown to require RBPJ for EBNA3C-mediated repression. We have described the sequence of events during repression and challenge a widely held assumption that if a protein interacts with RBPJ it would be recruited to DNA because of the intrinsic capacity of RBPJ to bind specific sequences. We show that interaction with RBPJ is essential for the repression of all three genes during the infection of B cells by EBV, but that RBPJ itself is only recruited to the genes when EBNA3C is functional. These data suggest an unexpectedly complex interaction of multiple proteins when EBNA3C prevents the expression of cellular genes.
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Epigenetic Alterations in Epstein-Barr Virus-Associated Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 879:39-69. [PMID: 26659263 DOI: 10.1007/978-3-319-24738-0_3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Oxidative stress enables Epstein-Barr virus-induced B-cell transformation by posttranscriptional regulation of viral and cellular growth-promoting factors. Oncogene 2015; 35:3807-16. [PMID: 26592445 DOI: 10.1038/onc.2015.450] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/14/2015] [Accepted: 10/22/2015] [Indexed: 12/13/2022]
Abstract
Infection of human B lymphocytes by Epstein-Barr virus (EBV) leads to the establishment of immortalized lymphoblastoid cell lines (LCLs) that are widely used as a model of viral oncogenesis. An early consequence of infection is the induction of DNA damage and activation of the DNA damage response, which limits the efficiency of growth transformation. The cause of the DNA damage remains poorly understood. We have addressed this question by comparing the response of B lymphocytes infected with EBV or stimulated with a potent B-cell mitogen. We found that although the two stimuli induce comparable proliferation during the first 10 days of culture, the EBV-infected blasts showed significantly higher levels of DNA damage, which correlated with stronger and sustained accumulation of reactive oxygen species (ROS). Treatment with ROS scavengers decreased DNA damage in both mitogen-stimulated and EBV-infected cells. However, while mitogen-induced proliferation was slightly improved, the proliferation of EBV-infected cells and the establishment of LCLs were severely impaired. Quenching of ROS did not affect the kinetics and magnitude of viral gene expression but was associated with selective downregulation of the viral LMP1 and phosphorylated cellular transcription factor STAT3 that have key roles in transformation. Analysis of the mechanism by which high levels of ROS support LMP1 expression revealed selective inhibition of viral microRNAs that target the LMP1 transcript. Our study provides novel insights into the role of EBV-induced oxidative stress in promoting B-cell immortalization and malignant transformation.
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Epstein-Barr Virus Proteins EBNA3A and EBNA3C Together Induce Expression of the Oncogenic MicroRNA Cluster miR-221/miR-222 and Ablate Expression of Its Target p57KIP2. PLoS Pathog 2015; 11:e1005031. [PMID: 26153983 PMCID: PMC4496050 DOI: 10.1371/journal.ppat.1005031] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/18/2015] [Indexed: 12/27/2022] Open
Abstract
We show that two host-encoded primary RNAs (pri-miRs) and the corresponding microRNA (miR) clusters--widely reported to have cell transformation-associated activity--are regulated by EBNA3A and EBNA3C. Utilising a variety of EBV-transformed lymphoblastoid cell lines (LCLs) carrying knockout-, revertant- or conditional-EBV recombinants, it was possible to demonstrate unambiguously that EBNA3A and EBNA3C are both required for transactivation of the oncogenic miR-221/miR-222 cluster that is expressed at high levels in multiple human tumours--including lymphoma/leukemia. ChIP, ChIP-seq, and chromosome conformation capture analyses indicate that this activation results from direct targeting of both EBV proteins to chromatin at the miR-221/miR-222 genomic locus and activation via a long-range interaction between enhancer elements and the transcription start site of a long non-coding pri-miR located 28 kb upstream of the miR sequences. Reduced levels of miR-221/miR-222 produced by inactivation or deletion of EBNA3A or EBNA3C resulted in increased expression of the cyclin-dependent kinase inhibitor p57KIP2, a well-established target of miR-221/miR-222. MiR blocking experiments confirmed that miR-221/miR-222 target p57KIP2 expression in LCLs. In contrast, EBNA3A and EBNA3C are necessary to silence the tumour suppressor cluster miR-143/miR-145, but here ChIP-seq suggests that repression is probably indirect. This miR cluster is frequently down-regulated or deleted in human cancer, however, the targets in B cells are unknown. Together these data indicate that EBNA3A and EBNA3C contribute to B cell transformation by inhibiting multiple tumour suppressor proteins, not only by direct repression of protein-encoding genes, but also by the manipulation of host long non-coding pri-miRs and miRs.
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Abstract
Latent Epstein–Barr virus (EBV) infection has a substantial role in causing many human disorders. The persistence of these viral genomes in all malignant cells, yet with the expression of limited latent genes, is consistent with the notion that EBV latent genes are important for malignant cell growth. While the EBV-encoded nuclear antigen-1 (EBNA-1) and latent membrane protein-2A (LMP-2A) are critical, the EBNA-leader proteins, EBNA-2, EBNA-3A, EBNA-3C and LMP-1, are individually essential for in vitro transformation of primary B cells to lymphoblastoid cell lines. EBV-encoded RNAs and EBNA-3Bs are dispensable. In this review, the roles of EBV latent genes are summarized.
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Affiliation(s)
- Myung-Soo Kang
- 1] Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Samsung Medical Center, Sungkyunkwan University, Seoul, Korea [2] Samsung Biomedical Research Institute (SBRI), Samsung Medical Center, Sungkyunkwan University, Seoul, Korea
| | - Elliott Kieff
- Department of Medicine, Brigham and Women's Hospital, Program in Virology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
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The EBNA3 Family: Two Oncoproteins and a Tumour Suppressor that Are Central to the Biology of EBV in B Cells. Curr Top Microbiol Immunol 2015; 391:61-117. [PMID: 26428372 DOI: 10.1007/978-3-319-22834-1_3] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Epstein-Barr virus nuclear antigens EBNA3A , EBNA3B and EBNA3C are a family of three large latency-associated proteins expressed in B cells induced to proliferate by the virus. Together with the other nuclear antigens (EBNA-LP, EBNA2 and EBNA1), they are expressed from a polycistronic transcription unit that is probably unique to B cells. However, compared with the other EBNAs, hitherto the EBNA3 proteins were relatively neglected and their roles in EBV biology rather poorly understood. In recent years, powerful new technologies have been used to show that these proteins are central to the latency of EBV in B cells, playing major roles in reprogramming the expression of host genes affecting cell proliferation, survival, differentiation and immune surveillance. This indicates that the EBNA3s are critical in EBV persistence in the B cell system and in modulating B cell lymphomagenesis. EBNA3A and EBNA3C are necessary for the efficient proliferation of EBV-infected B cells because they target important tumour suppressor pathways--so operationally they are considered oncoproteins. In contrast, it is emerging that EBNA3B restrains the oncogenic capacity of EBV, so it can be considered a tumour suppressor--to our knowledge the first to be described in a tumour virus. Here, we provide a general overview of the EBNA3 genes and proteins. In particular, we describe recent research that has highlighted the complexity of their functional interactions with each other, with specific sites on the human genome and with the molecular machinery that controls transcription and epigenetic states of diverse host genes.
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Abstract
Persistent infection by EBV is explained by the germinal center model (GCM) which provides a satisfying and currently the only explanation for EBVs disparate biology. Since the GCM touches on every aspect of the virus, this chapter will serve as an introduction to the subsequent chapters. EBV is B lymphotropic, and its biology closely follows that of normal mature B lymphocytes. The virus persists quiescently in resting memory B cells for the lifetime of the host in a non-pathogenic state that is also invisible to the immune response. To access this compartment, the virus infects naïve B cells in the lymphoepithelium of the tonsils and activates these cells using the growth transcription program. These cells migrate to the GC where they switch to a more limited transcription program, the default program, which helps rescue them into the memory compartment where the virus persists. For egress, the infected memory cells return to the lymphoepithelium where they occasionally differentiate into plasma cells activating viral replication. The released virus can either infect more naïve B cells or be amplified in the epithelium for shedding. This cycle of infection and the quiescent state in memory B cells allow for lifetime persistence at a very low level that is remarkably stable over time. Mathematically, this is a stable fixed point where the mechanisms regulating persistence drive the state back to equilibrium when perturbed. This is the GCM of EBV persistence. Other possible sites and mechanisms of persistence will also be discussed.
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Epstein-Barr virus nuclear antigen 3A partially coincides with EBNA3C genome-wide and is tethered to DNA through BATF complexes. Proc Natl Acad Sci U S A 2014; 112:554-9. [PMID: 25540416 DOI: 10.1073/pnas.1422580112] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Epstein-Barr Virus (EBV) conversion of B-lymphocytes to Lymphoblastoid Cell Lines (LCLs) requires four EBV nuclear antigen (EBNA) oncoproteins: EBNA2, EBNALP, EBNA3A, and EBNA3C. EBNA2 and EBNALP associate with EBV and cell enhancers, up-regulate the EBNA promoter, MYC, and EBV Latent infection Membrane Proteins (LMPs), which up-regulate BCL2 to protect EBV-infected B-cells from MYC proliferation-induced cell death. LCL proliferation induces p16(INK4A) and p14(ARF)-mediated cell senescence. EBNA3A and EBNA3C jointly suppress p16(INK4A) and p14(ARF), enabling continuous cell proliferation. Analyses of the EBNA3A human genome-wide ChIP-seq landscape revealed 37% of 10,000 EBNA3A sites to be at strong enhancers; 28% to be at weak enhancers; 4.4% to be at active promoters; and 6.9% to be at weak and poised promoters. EBNA3A colocalized with BATF-IRF4, ETS-IRF4, RUNX3, and other B-cell Transcription Factors (TFs). EBNA3A sites clustered into seven unique groups, with differing B-cell TFs and epigenetic marks. EBNA3A coincidence with BATF-IRF4 or RUNX3 was associated with stronger EBNA3A ChIP-Seq signals. EBNA3A was at MYC, CDKN2A/B, CCND2, CXCL9/10, and BCL2, together with RUNX3, BATF, IRF4, and SPI1. ChIP-re-ChIP revealed complexes of EBNA3A on DNA with BATF. These data strongly support a model in which EBNA3A is tethered to DNA through a BATF-containing protein complexes to enable continuous cell proliferation.
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Hui KF, Leung YY, Yeung PL, Middeldorp JM, Chiang AKS. Combination of SAHA and bortezomib up-regulates CDKN2A and CDKN1A and induces apoptosis of Epstein-Barr virus-positive Wp-restricted Burkitt lymphoma and lymphoblastoid cell lines. Br J Haematol 2014; 167:639-50. [PMID: 25155625 DOI: 10.1111/bjh.13089] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 07/15/2014] [Indexed: 01/22/2023]
Abstract
Epstein-Barr virus (EBV) latent proteins exert anti-apoptotic effects on EBV-transformed lymphoid cells by down-regulating BCL2L11 (BIM), CDKN2A (p16(INK4A) ) and CDKN1A (p21(WAF1) ). However, the potential therapeutic effects of targeting these anti-apoptotic mechanisms remain unexplored. Here, we tested both in vitro and in vivo effects of the combination of histone deacetylase (HDAC) and proteasome inhibitors on the apoptosis of six endemic Burkitt lymphoma (BL) lines of different latency patterns (types I and III and Wp-restricted) and three lymphoblastoid cell lines (LCLs). We found that the combination of HDAC and proteasome inhibitors (e.g. SAHA/bortezomib) synergistically induced the killing of Wp-restricted and latency III BL and LCLs but not latency I BL cells. The synergistic killing was due to apoptosis, as evidenced by the high percentage of annexin V positivity and strong cleavage of PARP1 (PARP) and CASP3 (caspase-3). Concomitantly, SAHA/bortezomib up-regulated the expression of CDKN2A and CDKN1A but did not affect the level of BCL2L11 or BHRF1 (viral homologue of BCL2). The apoptotic effects were dependent on reactive oxygen species generation. Furthermore, SAHA/bortezomib suppressed the growth of Wp-restricted BL xenografts in nude mice. This study provides the rationale to test the novel application of SAHA/bortezomib on the treatment of EBV-associated Wp-restricted BL and post-transplant lymphoproliferative disorder.
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Affiliation(s)
- Kwai Fung Hui
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong, SAR, China
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Banerjee S, Lu J, Cai Q, Sun Z, Jha HC, Robertson ES. EBNA3C augments Pim-1 mediated phosphorylation and degradation of p21 to promote B-cell proliferation. PLoS Pathog 2014; 10:e1004304. [PMID: 25121590 PMCID: PMC4133388 DOI: 10.1371/journal.ppat.1004304] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 06/28/2014] [Indexed: 12/11/2022] Open
Abstract
Epstein–Barr virus (EBV), a ubiquitous human herpesvirus, can latently infect the human population. EBV is associated with several types of malignancies originating from lymphoid and epithelial cell types. EBV latent antigen 3C (EBNA3C) is essential for EBV-induced immortalization of B-cells. The Moloney murine leukemia provirus integration site (PIM-1), which encodes an oncogenic serine/threonine kinase, is linked to several cellular functions involving cell survival, proliferation, differentiation, and apoptosis. Notably, enhanced expression of Pim-1 kinase is associated with numerous hematological and non-hematological malignancies. A higher expression level of Pim-1 kinase is associated with EBV infection, suggesting a crucial role for Pim-1 in EBV-induced tumorigenesis. We now demonstrate a molecular mechanism which reveals a direct role for EBNA3C in enhancing Pim-1 expression in EBV-infected primary B-cells. We also showed that EBNA3C is physically associated with Pim-1 through its amino-terminal domain, and also forms a molecular complex in B-cells. EBNA3C can stabilize Pim-1 through abrogation of the proteasome/Ubiquitin pathway. Our results demonstrate that EBNA3C enhances Pim-1 mediated phosphorylation of p21 at the Thr145 residue. EBNA3C also facilitated the nuclear localization of Pim-1, and promoted EBV transformed cell proliferation by altering Pim-1 mediated regulation of the activity of the cell-cycle inhibitor p21/WAF1. Our study demonstrated that EBNA3C significantly induces Pim-1 mediated proteosomal degradation of p21. A significant reduction in cell proliferation of EBV-transformed LCLs was observed upon stable knockdown of Pim-1. This study describes a critical role for the oncoprotein Pim-1 in EBV-mediated oncogenesis, as well as provides novel insights into oncogenic kinase-targeted therapeutic intervention of EBV-associated cancers. The oncogenic serine/threonine kinase Pim-1 is upregulated in a number of human cancers including lymphomas, gastric, colorectal and prostate carcinomas. EBV nuclear antigen 3C (EBNA3C) is essential for EBV-induced transformation of human primary B-lymphocytes. Our current study revealed that EBNA3C significantly enhances Pim-1 kinase expression at both the transcript and protein levels. EBNA3C also interacts with Pim-1 and can form a complex in EBV-transformed cells. Moreover, EBNA3C increases nuclear localization of Pim-1 and stabilizes Pim-1 protein levels by inhibiting its poly-ubiquitination. Additionally, EBNA3C augments Pim-1 mediated phosphorylation of p21 and its proteosomal degradation. Stable knockdown of Pim-1 using si-RNA showed a significant decrease in proliferation of EBV transformed lymphoblastoid cell lines and subsequent induction of apoptosis by triggering the intrinsic apoptotic pathway. Therefore, our study demonstrated a new mechanism by which the oncogenic Pim-1 kinase targeted by EBV latent antigen 3C can inhibit p21 function, and is therefore a potential therapeutic target for the treatment of EBV-associated malignancies.
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Affiliation(s)
- Shuvomoy Banerjee
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jie Lu
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Qiliang Cai
- Key Laboratory of Molecular Medical Virology (Ministries of Education and Health), School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
| | - Zhiguo Sun
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Hem Chandra Jha
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Erle S. Robertson
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Bazot Q, Deschamps T, Tafforeau L, Siouda M, Leblanc P, Harth-Hertle ML, Rabourdin-Combe C, Lotteau V, Kempkes B, Tommasino M, Gruffat H, Manet E. Epstein-Barr virus nuclear antigen 3A protein regulates CDKN2B transcription via interaction with MIZ-1. Nucleic Acids Res 2014; 42:9700-16. [PMID: 25092922 PMCID: PMC4150796 DOI: 10.1093/nar/gku697] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The Epstein-Barr virus (EBV) nuclear antigen 3 family of protein is critical for the EBV-induced primary B-cell growth transformation process. Using a yeast two-hybrid screen we identified 22 novel cellular partners of the EBNA3s. Most importantly, among the newly identified partners, five are known to play direct and important roles in transcriptional regulation. Of these, the Myc-interacting zinc finger protein-1 (MIZ-1) is a transcription factor initially characterized as a binding partner of MYC. MIZ-1 activates the transcription of a number of target genes including the cell cycle inhibitor CDKN2B. Focusing on the EBNA3A/MIZ-1 interaction we demonstrate that binding occurs in EBV-infected cells expressing both proteins at endogenous physiological levels and that in the presence of EBNA3A, a significant fraction of MIZ-1 translocates from the cytoplasm to the nucleus. Moreover, we show that a trimeric complex composed of a MIZ-1 recognition DNA element, MIZ-1 and EBNA3A can be formed, and that interaction of MIZ-1 with nucleophosmin (NPM), one of its coactivator, is prevented by EBNA3A. Finally, we show that, in the presence of EBNA3A, expression of the MIZ-1 target gene, CDKN2B, is downregulated and repressive H3K27 marks are established on its promoter region suggesting that EBNA3A directly counteracts the growth inhibitory action of MIZ-1.
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Affiliation(s)
- Quentin Bazot
- CIRI, International Center for Infectiology Research, Oncogenic Herpesviruses team, Université de Lyon, Lyon 69364, France Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France
| | - Thibaut Deschamps
- CIRI, International Center for Infectiology Research, Oncogenic Herpesviruses team, Université de Lyon, Lyon 69364, France Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France
| | - Lionel Tafforeau
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France Ecole Normale Supérieure de Lyon, Lyon 69364, France
| | - Maha Siouda
- International Agency for Research on Cancer, World Health Organization, Lyon 69372, France
| | - Pascal Leblanc
- CNRS, UMR5308, Lyon 69364, France CNRS UMR5239, Laboratoire de Biologie de la Cellule, Lyon 69364, France
| | - Marie L Harth-Hertle
- Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany
| | - Chantal Rabourdin-Combe
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France Ecole Normale Supérieure de Lyon, Lyon 69364, France
| | - Vincent Lotteau
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France Ecole Normale Supérieure de Lyon, Lyon 69364, France
| | - Bettina Kempkes
- Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany
| | - Massimo Tommasino
- International Agency for Research on Cancer, World Health Organization, Lyon 69372, France
| | - Henri Gruffat
- CIRI, International Center for Infectiology Research, Oncogenic Herpesviruses team, Université de Lyon, Lyon 69364, France Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France
| | - Evelyne Manet
- CIRI, International Center for Infectiology Research, Oncogenic Herpesviruses team, Université de Lyon, Lyon 69364, France Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France
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Price AM, Luftig MA. Dynamic Epstein-Barr virus gene expression on the path to B-cell transformation. Adv Virus Res 2014; 88:279-313. [PMID: 24373315 DOI: 10.1016/b978-0-12-800098-4.00006-4] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Epstein-Barr virus (EBV) is an oncogenic human herpesvirus in the γ-herpesvirinae subfamily that contains a 170-180kb double-stranded DNA genome. In vivo, EBV commonly infects B and epithelial cells and persists for the life of the host in a latent state in the memory B-cell compartment of the peripheral blood. EBV can be reactivated from its latent state, leading to increased expression of lytic genes that primarily encode for enzymes necessary to replicate the viral genome and structural components of the virion. Lytic cycle proteins also aid in immune evasion, inhibition of apoptosis, and the modulation of other host responses to infection. In vitro, EBV has the potential to infect primary human B cells and induce cellular proliferation to yield effectively immortalized lymphoblastoid cell lines, or LCLs. EBV immortalization of B cells in vitro serves as a model system for studying EBV-mediated lymphomagenesis. While much is known about the steady-state viral gene expression within EBV-immortalized LCLs and other EBV-positive cell lines, relatively little is known about the early events after primary B-cell infection. It was previously thought that upon latent infection, EBV only expressed the well-characterized latency-associated transcripts found in LCLs. However, recent work has characterized the early, but transient, expression of lytic genes necessary for efficient transformation and delayed responses in the known latency genes. This chapter summarizes these recent findings that show how dynamic and controlled expression of multiple EBV genes can control the activation of B cells, entry into the cell cycle, the inhibition of apoptosis, and innate and adaptive immune responses.
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Affiliation(s)
- Alexander M Price
- Department of Molecular Genetics and Microbiology, Center for Virology, Duke University Medical Center, Durham, North Carolina, 27710 USA
| | - Micah A Luftig
- Department of Molecular Genetics and Microbiology, Center for Virology, Duke University Medical Center, Durham, North Carolina, 27710 USA.
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Silmon de Monerri NC, Kim K. Pathogens hijack the epigenome: a new twist on host-pathogen interactions. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:897-911. [PMID: 24525150 DOI: 10.1016/j.ajpath.2013.12.022] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 12/01/2013] [Accepted: 12/05/2013] [Indexed: 02/07/2023]
Abstract
Pathogens have evolved strategies to promote their survival by dramatically modifying the transcriptional profile and protein content of the host cells they infect. Modifications of the host transcriptome and proteome are mediated by pathogen-encoded effector molecules that modulate host cells through a variety of different mechanisms. Recent studies highlight the importance of the host chromatin and other epigenetic regulators as targets of pathogens. Host gene regulatory mechanisms may be targeted through cytoplasmic signaling, directly by pathogen effector proteins, and possibly by pathogen RNA. Although many of these changes are short-lived and persist only during the course of infection, several studies indicate that pathogens are able to induce long-term, heritable changes that are essential to pathogenesis of infectious diseases and persistence of pathogens within their hosts. In this review, we discuss how pathogens modulate the epigenome of host cells, a new and flourishing avenue of host-pathogen interaction studies.
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Affiliation(s)
- Natalie C Silmon de Monerri
- Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York
| | - Kami Kim
- Departments of Medicine, Pathology, and Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York.
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43
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Epstein-Barr virus nuclear antigen 3C binds to BATF/IRF4 or SPI1/IRF4 composite sites and recruits Sin3A to repress CDKN2A. Proc Natl Acad Sci U S A 2013; 111:421-6. [PMID: 24344258 DOI: 10.1073/pnas.1321704111] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Epstein-Barr virus nuclear antigen 3C (EBNA3C) repression of CDKN2A p14(ARF) and p16(INK4A) is essential for immortal human B-lymphoblastoid cell line (LCL) growth. EBNA3C ChIP-sequencing identified >13,000 EBNA3C sites in LCL DNA. Most EBNA3C sites were associated with active transcription; 64% were strong H3K4me1- and H3K27ac-marked enhancers and 16% were active promoters marked by H3K4me3 and H3K9ac. Using ENCODE LCL transcription factor ChIP-sequencing data, EBNA3C sites coincided (±250 bp) with RUNX3 (64%), BATF (55%), ATF2 (51%), IRF4 (41%), MEF2A (35%), PAX5 (34%), SPI1 (29%), BCL11a (28%), SP1 (26%), TCF12 (23%), NF-κB (23%), POU2F2 (23%), and RBPJ (16%). EBNA3C sites separated into five distinct clusters: (i) Sin3A, (ii) EBNA2/RBPJ, (iii) SPI1, and (iv) strong or (v) weak BATF/IRF4. EBNA3C signals were positively affected by RUNX3, BATF/IRF4 (AICE) and SPI1/IRF4 (EICE) cooccupancy. Gene set enrichment analyses correlated EBNA3C/Sin3A promoter sites with transcription down-regulation (P < 1.6 × 10(-4)). EBNA3C signals were strongest at BATF/IRF4 and SPI1/IRF4 composite sites. EBNA3C bound strongly to the p14(ARF) promoter through SPI1/IRF4/BATF/RUNX3, establishing RBPJ-, Sin3A-, and REST-mediated repression. EBNA3C immune precipitated with Sin3A and conditional EBNA3C inactivation significantly decreased Sin3A binding at the p14(ARF) promoter (P < 0.05). These data support a model in which EBNA3C binds strongly to BATF/IRF4/SPI1/RUNX3 sites to enhance transcription and recruits RBPJ/Sin3A- and REST/NRSF-repressive complexes to repress p14(ARF) and p16(INK4A) expression.
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Sahu SK, Mohanty S, Kumar A, Kundu CN, Verma SC, Choudhuri T. Epstein-Barr virus nuclear antigen 3C interact with p73: Interplay between a viral oncoprotein and cellular tumor suppressor. Virology 2013; 448:333-43. [PMID: 24314664 DOI: 10.1016/j.virol.2013.10.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 03/15/2013] [Accepted: 10/17/2013] [Indexed: 12/12/2022]
Abstract
The p73 protein has structural and functional homology with the tumor suppressor p53, which plays an important role in cell cycle regulation, apoptosis, and DNA repair. The p73 locus encodes both a tumor suppressor (TAp73) and a putative oncogene (ΔNp73). p73 May play a significant role in p53-deficient lymphomas infected with Epstein-Barr virus (EBV). EBV produces an asymptomatic infection in the majority of the global population, but it is associated with several human B-cell malignancies. The EBV-encoded Epstein-Barr virus nuclear antigen 3C (EBNA3C) is thought to disrupt the cell cycle checkpoint by interacting directly with p53 family proteins. Doxorubicin, a commonly used chemotherapeutic agent, induces apoptosis through p53 and p73 signaling such that the lowΔNp73 level promotes the p73-mediated intrinsic pathway of apoptosis. In this report, we investigated the mechanism by which EBV infection counters p73α-induced apoptosis through EBNA3C.
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Affiliation(s)
- Sushil Kumar Sahu
- Division of Infectious Disease Biology, Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar 751023, India
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45
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Harth-Hertle ML, Scholz BA, Erhard F, Glaser LV, Dölken L, Zimmer R, Kempkes B. Inactivation of intergenic enhancers by EBNA3A initiates and maintains polycomb signatures across a chromatin domain encoding CXCL10 and CXCL9. PLoS Pathog 2013; 9:e1003638. [PMID: 24068939 PMCID: PMC3777872 DOI: 10.1371/journal.ppat.1003638] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 08/03/2013] [Indexed: 01/28/2023] Open
Abstract
Epstein-Barr virus (EBV) causes a persistent infection in human B cells by establishing specific transcription programs to control B cell activation and differentiation. Transcriptional reprogramming of EBV infected B cells is predominantly driven by the action of EBV nuclear antigens, among them the transcriptional repressor EBNA3A. By comparing gene expression profiles of wt and EBNA3A negative EBV infected B cells, we have previously identified a broad array of cellular genes controlled by EBNA3A. We now find that genes repressed by EBNA3A in these cells are significantly enriched for the repressive histone mark H3K27me3, which is installed by Polycomb group (PcG) proteins. This PcG-controlled subset of genes also carries H3K27me3 marks in a variety of other tissues, suggesting that the commitment to PcG silencing is an intrinsic feature of these gene loci that can be used by EBNA3A. In addition, EBNA3A targets frequently reside in co-regulated gene clusters. To study the mechanism of gene repression by EBNA3A and to evaluate the relative contribution of PcG proteins during this process, we have selected the genomic neighbors CXCL10 and CXCL9 as a model for co-repressed and PcG-controlled genes. We show that EBNA3A binds to CBF1 occupied intergenic enhancers located between CXCL10 and CXCL9 and displaces the transactivator EBNA2. This impairs enhancer activity, resulting in a rapid transcriptional shut-down of both genes in a CBF1-dependent manner and initiation of a delayed gain of H3K27me3 marks covering an extended chromatin domain. H3K27me3 marks increase gradually and are maintained by EBNA3A. Our study provides direct evidence that repression by EBNA3A requires CBF1 and that EBNA3A and EBNA2 compete for access to CBF1 at identical genomic sites. Most importantly, our results demonstrate that transcriptional silencing by EBNA3A precedes the appearance of repressive PcG marks and indicate that both events are triggered by loss of enhancer activity. Epstein-Barr virus (EBV) is a γ-herpesvirus which establishes a latent infection in human B cells and is associated with the pathogenesis of several types of cancer. Here, we report that cellular genes repressed by the EBV nuclear antigen 3A (EBNA3A) in EBV infected B cells frequently form contiguous clusters in the human genome and are committed to epigenetic silencing by Polycomb group (PcG) proteins. The chemokine genes CXCL10 and CXCL9 and their receptors on NK and T cells are critical weapons of the infected host to control herpesvirus infections. CXCL10 and CXCL9 are close neighbors within an extended PcG-controlled domain. We show that EBNA3A binds to intergenic enhancers located between CXCL10 and CXCL9 and displaces the transactivator EBNA2. This process impairs enhancer activity, resulting in a rapid transcriptional shut-down of both genes followed by a delayed gain of PcG histone marks. These PcG marks increase within the following weeks and are maintained by EBNA3A. Our results show that rapid transcriptional shut-down of distal genes and domain-wide PcG silencing is triggered by loss of enhancer activity and suggest that EBNA3A can reprogram the cellular genome in order to escape the immune surveillance of the host.
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Affiliation(s)
- Marie L. Harth-Hertle
- Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany
| | - Barbara A. Scholz
- Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany
| | - Florian Erhard
- Institut für Informatik, Ludwig-Maximilians-Universität München, München, Germany
| | - Laura V. Glaser
- Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany
| | - Lars Dölken
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Ralf Zimmer
- Institut für Informatik, Ludwig-Maximilians-Universität München, München, Germany
| | - Bettina Kempkes
- Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany
- * E-mail:
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46
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McClellan MJ, Wood CD, Ojeniyi O, Cooper TJ, Kanhere A, Arvey A, Webb HM, Palermo RD, Harth-Hertle ML, Kempkes B, Jenner RG, West MJ. Modulation of enhancer looping and differential gene targeting by Epstein-Barr virus transcription factors directs cellular reprogramming. PLoS Pathog 2013; 9:e1003636. [PMID: 24068937 PMCID: PMC3771879 DOI: 10.1371/journal.ppat.1003636] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Accepted: 08/03/2013] [Indexed: 12/28/2022] Open
Abstract
Epstein-Barr virus (EBV) epigenetically reprogrammes B-lymphocytes to drive immortalization and facilitate viral persistence. Host-cell transcription is perturbed principally through the actions of EBV EBNA 2, 3A, 3B and 3C, with cellular genes deregulated by specific combinations of these EBNAs through unknown mechanisms. Comparing human genome binding by these viral transcription factors, we discovered that 25% of binding sites were shared by EBNA 2 and the EBNA 3s and were located predominantly in enhancers. Moreover, 80% of potential EBNA 3A, 3B or 3C target genes were also targeted by EBNA 2, implicating extensive interplay between EBNA 2 and 3 proteins in cellular reprogramming. Investigating shared enhancer sites neighbouring two new targets (WEE1 and CTBP2) we discovered that EBNA 3 proteins repress transcription by modulating enhancer-promoter loop formation to establish repressive chromatin hubs or prevent assembly of active hubs. Re-ChIP analysis revealed that EBNA 2 and 3 proteins do not bind simultaneously at shared sites but compete for binding thereby modulating enhancer-promoter interactions. At an EBNA 3-only intergenic enhancer site between ADAM28 and ADAMDEC1 EBNA 3C was also able to independently direct epigenetic repression of both genes through enhancer-promoter looping. Significantly, studying shared or unique EBNA 3 binding sites at WEE1, CTBP2, ITGAL (LFA-1 alpha chain), BCL2L11 (Bim) and the ADAMs, we also discovered that different sets of EBNA 3 proteins bind regulatory elements in a gene and cell-type specific manner. Binding profiles correlated with the effects of individual EBNA 3 proteins on the expression of these genes, providing a molecular basis for the targeting of different sets of cellular genes by the EBNA 3s. Our results therefore highlight the influence of the genomic and cellular context in determining the specificity of gene deregulation by EBV and provide a paradigm for host-cell reprogramming through modulation of enhancer-promoter interactions by viral transcription factors. Epstein-Barr virus (EBV) is associated with numerous cancers. The ability of the virus to infect B-cells and convert them from short-lived into immortal cells is the key to its cancer-promoting properties. A small number of EBV transcription factors are required for immortalization and act in concert to drive cell growth by deregulating the expression of cellular genes through largely unknown mechanisms. We have demonstrated that four of these key transcription factors function cooperatively by targeting common genes via long-range enhancer elements and modulating their looping interactions with gene promoters. Specifically we show that gene repression by the EBV EBNA 3 family of proteins can be mediated through the modulation of enhancer-promoter looping. Our results also reveal that different subsets of EBNA 3 proteins are bound at different genes and that this differential binding can vary in lymphoma cells compared to cells immortalized in culture, indicating that cell-background-specific gene regulation may be important in lymphoma development. Our results demonstrate how cellular genes can be deregulated by an oncogenic virus through modulation of enhancer-promoter looping with the specificity of binding by viral transcription factors controlling cellular reprogramming in a gene and cell-type specific manner.
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Affiliation(s)
- Michael J. McClellan
- School of Life Sciences, John Maynard-Smith Building, University of Sussex, Falmer, Brighton, United Kingdom
| | - C. David Wood
- School of Life Sciences, John Maynard-Smith Building, University of Sussex, Falmer, Brighton, United Kingdom
| | - Opeoluwa Ojeniyi
- School of Life Sciences, John Maynard-Smith Building, University of Sussex, Falmer, Brighton, United Kingdom
| | - Tim J. Cooper
- School of Life Sciences, John Maynard-Smith Building, University of Sussex, Falmer, Brighton, United Kingdom
| | - Aditi Kanhere
- MRC Centre for Medical Molecular Virology, Division of Infection and Immunity, Paul O'Gorman Building, University College London, London, United Kingdom
| | - Aaron Arvey
- Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Helen M. Webb
- School of Life Sciences, John Maynard-Smith Building, University of Sussex, Falmer, Brighton, United Kingdom
| | - Richard D. Palermo
- School of Life Sciences, John Maynard-Smith Building, University of Sussex, Falmer, Brighton, United Kingdom
| | - Marie L. Harth-Hertle
- Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany
| | - Bettina Kempkes
- Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany
| | - Richard G. Jenner
- MRC Centre for Medical Molecular Virology, Division of Infection and Immunity, Paul O'Gorman Building, University College London, London, United Kingdom
| | - Michelle J. West
- School of Life Sciences, John Maynard-Smith Building, University of Sussex, Falmer, Brighton, United Kingdom
- * E-mail:
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47
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Saha A, Robertson ES. Impact of EBV essential nuclear protein EBNA-3C on B-cell proliferation and apoptosis. Future Microbiol 2013; 8:323-52. [PMID: 23464371 DOI: 10.2217/fmb.12.147] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
For over 40 years, EBV infection has been implicated in the etiology of a variety of lymphoid malignancies with the exceptional ability to drive resting B cells to continuously proliferate by successfully overriding cellular apoptotic stimuli. EBV utilizes the normal physiology of B-cell differentiation to persist within the memory B-cell pool of the immunocompetent host and subsequently establishes a life-long latent infection. During latency, out of a subset of viral genes expressed, EBNA-3C is one of the essential antigens required for in vitro primary B-cell transformation. EBNA-3C acts as a transcriptional coregulator by interacting with various cellular and viral factors. For the last 10 years, we have been actively engaged in discerning the biological significance of these interactions and revealed that EBNA-3C primarily targets two important cellular pathways - cell cycle and apoptosis. This review aims to summarize our current knowledge on EBNA-3C-mediated functions and describe how EBNA-3C seizes these cellular pathways that eventually promote B-cell lymphomagenesis. A scrupulous understanding of the critical relationship between EBNA-3C and these cellular machineries will not only aid in elucidating EBV pathogenesis, but also largely facilitate the development of novel diagnostic, as well as therapeutic, strategies against a vast range of EBV-associated B-cell lymphomas.
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Affiliation(s)
- Abhik Saha
- Presidency University, Department of Biotechnology, 86/1, College Street, Kolkata-700073, West Bengal, India
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48
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Guise AJ, Budayeva HG, Diner BA, Cristea IM. Histone deacetylases in herpesvirus replication and virus-stimulated host defense. Viruses 2013; 5:1607-32. [PMID: 23807710 PMCID: PMC3738950 DOI: 10.3390/v5071607] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 06/17/2013] [Accepted: 06/18/2013] [Indexed: 02/06/2023] Open
Abstract
Emerging evidence highlights a critical role for protein acetylation during herpesvirus infection. As prominent modulators of protein acetylation, histone deacetylases (HDACs) are essential transcriptional and epigenetic regulators. Not surprisingly, viruses have evolved a wide array of mechanisms to subvert HDAC functions. Here, we review the mechanisms underlying HDAC regulation during herpesvirus infection. We next discuss the roles of acetylation in host defense against herpesvirus infection. Finally, we provide a perspective on the contribution of current mass spectrometry-based “omic” technologies to infectious disease research, offering a systems biology view of infection.
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Affiliation(s)
| | | | | | - Ileana M. Cristea
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-609-258-9417; Fax: +1-609-258-4575
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49
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Herceg Z, Lambert MP, van Veldhoven K, Demetriou C, Vineis P, Smith MT, Straif K, Wild CP. Towards incorporating epigenetic mechanisms into carcinogen identification and evaluation. Carcinogenesis 2013; 34:1955-67. [PMID: 23749751 DOI: 10.1093/carcin/bgt212] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Remarkable progress in the field of epigenetics has turned academic, medical and public attention to the potential applications of these new advances in medicine and various fields of biomedical research. The result is a broader appreciation of epigenetic phenomena in the a etiology of common human diseases, most notably cancer. These advances also represent an exciting opportunity to incorporate epigenetics and epigenomics into carcinogen identification and safety assessment. Current epigenetic studies, including major international sequencing projects, are expected to generate information for establishing the 'normal' epigenome of tissues and cell types as well as the physiological variability of the epigenome against which carcinogen exposure can be assessed. Recently, epigenetic events have emerged as key mechanisms in cancer development, and while our search of the Monograph Volume 100 revealed that epigenetics have played a modest role in evaluating human carcinogens by the International Agency for Research on Cancer (IARC) Monographs so far, epigenetic data might play a pivotal role in the future. Here, we review (i) the current status of incorporation of epigenetics in carcinogen evaluation in the IARC Monographs Programme, (ii) potential modes of action for epigenetic carcinogens, (iii) current in vivo and in vitro technologies to detect epigenetic carcinogens, (iv) genomic regions and epigenetic modifications and their biological consequences and (v) critical technological and biological issues in assessment of epigenetic carcinogens. We also discuss the issues related to opportunities and challenges in the application of epigenetic testing in carcinogen identification and evaluation. Although the application of epigenetic assays in carcinogen evaluation is still in its infancy, important data are being generated and valuable scientific resources are being established that should catalyse future applications of epigenetic testing.
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Affiliation(s)
- Zdenko Herceg
- International Agency for Research on Cancer (IARC), 150 Cours Albert Thomas, F-69008 Lyon, France
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50
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Marek's disease virus infection induces widespread differential chromatin marks in inbred chicken lines. BMC Genomics 2012; 13:557. [PMID: 23072359 PMCID: PMC3505159 DOI: 10.1186/1471-2164-13-557] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 10/08/2012] [Indexed: 11/10/2022] Open
Abstract
Background Marek’s disease (MD) is a neoplastic disease in chickens caused by the MD virus (MDV). Successful vaccine development against MD has resulted in increased virulence of MDV and the understanding of genetic resistance to the disease is, therefore, crucial to long-term control strategies. Also, epigenetic factors are believed to be one of the major determinants of disease response. Results Here, we carried out comprehensive analyses of the epigenetic landscape induced by MDV, utilizing genome-wide histone H3 lysine 4 and lysine 27 trimethylation maps from chicken lines with varying resistance to MD. Differential chromatin marks were observed on genes previously implicated in the disease such as MX1 and CTLA-4 and also on genes reported in other cancers including IGF2BP1 and GAL. We detected bivalent domains on immune-related transcriptional regulators BCL6, CITED2 and EGR1, which underwent dynamic changes in both lines as a result of MDV infection. In addition, putative roles for GAL in the mechanism of MD progression were revealed. Conclusion Our results confirm the presence of widespread epigenetic differences induced by MD in chicken lines with different levels of genetic resistance. A majority of observed epigenetic changes were indicative of increased levels of viral infection in the susceptible line symptomatic of lowered immunocompetence in these birds caused by early cytolytic infection. The GAL system that has known anti-proliferative effects in other cancers is also revealed to be potentially involved in MD progression. Our study provides further insight into the mechanisms of MD progression while revealing a complex landscape of epigenetic regulatory mechanisms that varies depending on host factors.
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