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Han J, Jang KL. All-trans retinoic acid downregulates HBx levels via E6-associated protein-mediated proteasomal degradation to suppress hepatitis B virus replication. PLoS One 2024; 19:e0305350. [PMID: 38861553 PMCID: PMC11166335 DOI: 10.1371/journal.pone.0305350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 05/28/2024] [Indexed: 06/13/2024] Open
Abstract
All-trans retinoic acid (ATRA), recognized as the principal and most biologically potent metabolite of vitamin A, has been identified for its inhibitory effects on hepatitis B virus (HBV) replication. Nevertheless, the underlying mechanism remains elusive. The present study reveals that ATRA induces E6-associated protein (E6AP)-mediated proteasomal degradation of HBx to suppress HBV replication in human hepatoma cells in a p53-dependent pathway. For this effect, ATRA induced promoter hypomethylation of E6AP in the presence of HBx, which resulted in the upregulation of E6AP levels in HepG2 but not in Hep3B cells, emphasizing the p53-dependent nature of this effect. As a consequence, ATRA augmented the interaction between E6AP and HBx, resulting in substantial ubiquitination of HBx and consequent reduction in HBx protein levels in both the HBx overexpression system and the in vitro HBV replication model. Additionally, the knockdown of E6AP under ATRA treatment reduced the interaction between HBx and E6AP and decreased the ubiquitin-dependent proteasomal degradation of HBx, which prompted a recovery of HBV replication in the presence of ATRA, as confirmed by increased levels of intracellular HBV proteins and secreted HBV levels. This study not only contributes to the understanding of the complex interactions between ATRA, p53, E6AP, and HBx but also provides an academic basis for the clinical employment of ATRA in the treatment of HBV infection.
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Affiliation(s)
- Jiwoo Han
- Department of Integrated Biological Science, The Graduate School, Pusan National University, Busan, Republic of Korea
| | - Kyung Lib Jang
- Department of Integrated Biological Science, The Graduate School, Pusan National University, Busan, Republic of Korea
- Department of Microbiology, College of Natural Science, Pusan National University, Busan, Republic of Korea
- Microbiological Resource Research Institute, Pusan National University, Busan, Republic of Korea
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2
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Islam B, Yu HY, Duan TQ, Pan J, Li M, Zhang RQ, Masroor M, Huang JF. Cell cycle kinases (AUKA, CDK1, PLK1) are prognostic biomarkers and correlated with tumor-infiltrating leukocytes in HBV related HCC. J Biomol Struct Dyn 2023; 41:11845-11861. [PMID: 36634158 DOI: 10.1080/07391102.2022.2164056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 12/24/2022] [Indexed: 01/14/2023]
Abstract
Hepatocellular carcinoma (HCC) is one of the high incidence cancers and third leading cause of cancer-related mortality. HBV is the top most risk factor accounting for 50-80% of the HCC cases. Kinases: Aurora kinase A (AURKA), cyclin-dependent kinase (CDK1) and Polo-like kinase 1 (PLK1), the key regulators of cell mitosis are overexpressed in varieties of cancers including HCC. However, the exact role of these genes in prognosis of HCC is not fully unveiled. In addition, there is no such an accurate prognostic biomarker for HBV-related HCC. To address this issue, we performed a multidimensional analysis of AURKA, CDK1 and PLK1 with a series of publicly available databases in multiple cancers and with experimental validation in HBV-related HCC tissues. Overexpression of AURKA, CDK1 and PLK1 was found in multiple cancers including HCC. Elevated expression of these genes could result from lowered DNA methylation and genomic alterations. Transcriptional overexpression was significantly correlated with poor prognosis of HCC patients. The expression levels were also significantly positively associated with tumor grades and stages. Furthermore, the expression levels of these genes had a strong correlation with infiltration of immune cells. Our analysis shows that AURKA, CDK1 and PLK1 are correlated with immune infiltration and are the prognostic biomarkers for HBV-induced HCC.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Baitul Islam
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Hai-Yang Yu
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Tian-Qi Duan
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Jing Pan
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Min Li
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Ru-Qi Zhang
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
| | - Matiullah Masroor
- Department of Cardiovascular Surgery, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Ju-Fang Huang
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, China
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3
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Yang L, Zou T, Chen Y, Zhao Y, Wu X, Li M, Du F, Chen Y, Xiao Z, Shen J. Hepatitis B virus X protein mediated epigenetic alterations in the pathogenesis of hepatocellular carcinoma. Hepatol Int 2022; 16:741-754. [PMID: 35648301 DOI: 10.1007/s12072-022-10351-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/25/2022] [Indexed: 12/13/2022]
Abstract
Chronic hepatitis B virus (HBV) infection is a worldwide health problem. Hepatitis B virus X protein (HBx), a pleiotropic regulatory protein encoded by HBV, is necessary for the transcription of HBV covalently closed circular DNA (cccDNA) minichromosomes, and affects the epigenetic regulation of host cells. The epigenetic reprogramming of HBx on host cell genome is strongly involved in HBV-related HCC carcinogenesis. Here, we review the latest findings of the epigenetic regulation induced by HBx protein in hepatocellular carcinoma (HCC), including DNA methylation, histone modification and non-coding RNA expression. The influence of HBx on the epigenetic regulation of cccDNA is also summarized. In addition, preliminary studies of targeted drugs for epigenetic changes induced by HBx are also discussed. The exploration of epigenetic markers as potential targets will help to develop new prevention and/or treatment methods for HBx-related HCC.
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Affiliation(s)
- Liqiong Yang
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China
- Cell Therapy and Cell Drugs of Luzhou Key Laboratory, Luzhou, 646000, China
- South Sichuan Institute of Translational Medicine, Luzhou, 646000, China
| | - Tao Zou
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China
- Cell Therapy and Cell Drugs of Luzhou Key Laboratory, Luzhou, 646000, China
- South Sichuan Institute of Translational Medicine, Luzhou, 646000, China
| | - Yao Chen
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China
- Cell Therapy and Cell Drugs of Luzhou Key Laboratory, Luzhou, 646000, China
- South Sichuan Institute of Translational Medicine, Luzhou, 646000, China
| | - Yueshui Zhao
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China
- Cell Therapy and Cell Drugs of Luzhou Key Laboratory, Luzhou, 646000, China
- South Sichuan Institute of Translational Medicine, Luzhou, 646000, China
| | - Xu Wu
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China
- Cell Therapy and Cell Drugs of Luzhou Key Laboratory, Luzhou, 646000, China
- South Sichuan Institute of Translational Medicine, Luzhou, 646000, China
| | - Mingxing Li
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China
- Cell Therapy and Cell Drugs of Luzhou Key Laboratory, Luzhou, 646000, China
- South Sichuan Institute of Translational Medicine, Luzhou, 646000, China
| | - Fukuan Du
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China
- Cell Therapy and Cell Drugs of Luzhou Key Laboratory, Luzhou, 646000, China
- South Sichuan Institute of Translational Medicine, Luzhou, 646000, China
| | - Yu Chen
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China
- Cell Therapy and Cell Drugs of Luzhou Key Laboratory, Luzhou, 646000, China
- South Sichuan Institute of Translational Medicine, Luzhou, 646000, China
| | - Zhangang Xiao
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China.
- Cell Therapy and Cell Drugs of Luzhou Key Laboratory, Luzhou, 646000, China.
- South Sichuan Institute of Translational Medicine, Luzhou, 646000, China.
| | - Jing Shen
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, 646000, China.
- Cell Therapy and Cell Drugs of Luzhou Key Laboratory, Luzhou, 646000, China.
- South Sichuan Institute of Translational Medicine, Luzhou, 646000, China.
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4
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Melis M, Tang XH, Trasino SE, Gudas LJ. Retinoids in the Pathogenesis and Treatment of Liver Diseases. Nutrients 2022; 14:1456. [PMID: 35406069 PMCID: PMC9002467 DOI: 10.3390/nu14071456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/24/2022] [Accepted: 03/28/2022] [Indexed: 02/06/2023] Open
Abstract
Vitamin A (VA), all-trans-retinol (ROL), and its analogs are collectively called retinoids. Acting through the retinoic acid receptors RARα, RARβ, and RARγ, all-trans-retinoic acid, an active metabolite of VA, is a potent regulator of numerous biological pathways, including embryonic and somatic cellular differentiation, immune functions, and energy metabolism. The liver is the primary organ for retinoid storage and metabolism in humans. For reasons that remain incompletely understood, a body of evidence shows that reductions in liver retinoids, aberrant retinoid metabolism, and reductions in RAR signaling are implicated in numerous diseases of the liver, including hepatocellular carcinoma, non-alcohol-associated fatty liver diseases, and alcohol-associated liver diseases. Conversely, restoration of retinoid signaling, pharmacological treatments with natural and synthetic retinoids, and newer agonists for specific RARs show promising benefits for treatment of a number of these liver diseases. Here we provide a comprehensive review of the literature demonstrating a role for retinoids in limiting the pathogenesis of these diseases and in the treatment of liver diseases.
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Affiliation(s)
- Marta Melis
- Department of Pharmacology, Weill Cornell Medical College of Cornell University, New York, NY 10021, USA; (M.M.); (X.-H.T.)
| | - Xiao-Han Tang
- Department of Pharmacology, Weill Cornell Medical College of Cornell University, New York, NY 10021, USA; (M.M.); (X.-H.T.)
| | - Steven E. Trasino
- Nutrition Program, Hunter College, City University of New York, New York, NY 10065, USA;
| | - Lorraine J. Gudas
- Department of Pharmacology, Weill Cornell Medical College of Cornell University, New York, NY 10021, USA; (M.M.); (X.-H.T.)
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5
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Hepatitis B Viral Protein HBx and the Molecular Mechanisms Modulating the Hallmarks of Hepatocellular Carcinoma: A Comprehensive Review. Cells 2022; 11:cells11040741. [PMID: 35203390 PMCID: PMC8870387 DOI: 10.3390/cells11040741] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/10/2022] [Accepted: 02/16/2022] [Indexed: 02/06/2023] Open
Abstract
With 296 million cases estimated worldwide, chronic hepatitis B virus (HBV) infection is the most common risk factor for hepatocellular carcinoma (HCC). HBV-encoded oncogene X protein (HBx), a key multifunctional regulatory protein, drives viral replication and interferes with several cellular signalling pathways that drive virus-associated hepatocarcinogenesis. This review article provides a comprehensive overview of the role of HBx in modulating the various hallmarks of HCC by supporting tumour initiation, progression, invasion and metastasis. Understanding HBx-mediated dimensions of complexity in driving liver malignancies could provide the key to unlocking novel and repurposed combinatorial therapies to combat HCC.
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6
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Costantini L, Molinari R, Farinon B, Merendino N. Retinoic Acids in the Treatment of Most Lethal Solid Cancers. J Clin Med 2020; 9:E360. [PMID: 32012980 PMCID: PMC7073976 DOI: 10.3390/jcm9020360] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 01/21/2020] [Accepted: 01/24/2020] [Indexed: 12/14/2022] Open
Abstract
Although the use of oral administration of pharmacological all-trans retinoic acid (ATRA) concentration in acute promyelocytic leukaemia (APL) patients was approved for over 20 years and used as standard therapy still to date, the same use in solid cancers is still controversial. In the present review the literature about the top five lethal solid cancers (lung, stomach, liver, breast, and colon cancer), as defined by The Global Cancer Observatory of World Health Organization, and retinoic acids (ATRA, 9-cis retinoic acid, and 13-cis retinoic acid, RA) was compared. The action of retinoic acids in inhibiting the cell proliferation was found in several cell pathways and compartments: from membrane and cytoplasmic signaling, to metabolic enzymes, to gene expression. However, in parallel in the most aggressive phenotypes several escape routes have evolved conferring retinoic acids-resistance. The comparison between different solid cancer types pointed out that for some cancer types several information are still lacking. Moreover, even though some pathways and escape routes are the same between the cancer types, sometimes they can differently respond to retinoic acid therapy, so that generalization cannot be made. Further studies on molecular pathways are needed to perform combinatorial trials that allow overcoming retinoic acids resistance.
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Affiliation(s)
- Lara Costantini
- Department of Ecological and Biological Sciences (DEB), Tuscia University, Largo dell’Università snc, 01100 Viterbo, Italy
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7
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Tao S, Pan S, Gu C, Wei L, Kang N, Xie Y, Liu J. Characterization and engineering of broadly reactive monoclonal antibody against hepatitis B virus X protein that blocks its interaction with DDB1. Sci Rep 2019; 9:20323. [PMID: 31889135 PMCID: PMC6937242 DOI: 10.1038/s41598-019-56819-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 12/17/2019] [Indexed: 12/20/2022] Open
Abstract
Hepatitis B virus (HBV) X protein (HBx) plays diverse roles in both viral life cycle and HBV-related carcinogenesis. Its interaction with DNA damage-binding protein 1 (DDB1) was shown to be essential for engendering cellular conditions favorable for optimal viral transcription and replication. Previously, we described a mouse monoclonal antibody against HBx (anti-HBx 2A7) recognizing HBx encoded by representative strains from 7 of 8 known HBV genotypes. In this work, we further characterized 2A7 in order to explore its potential usefulness in HBx-targeting applications. We demonstrated that 2A7 recognizes a linear epitope mapped to L89PKVLHKR96 on HBx, a segment that is highly conserved across genotypes and coincidentally overlaps with the DDB1-interacting segment. HBx-DDB1 binding could be inhibited by 2A7 in vitro, suggesting therapeutic potential. Nucleic acid and amino acid sequences of 2A7 were then obtained, which allowed construction of recombinant antibody and single chain variable fragments (scFv). 2A7-derived recombinant antibody and scFv recapitulate 2A7's HBx-binding capacity and epitope specificity. We also reported preliminary results using cell-penetrating peptide for delivering 2A7 antibody across cell membrane to target intracellular HBx. Anti-HBx 2A7 and 2A7-derived scFv characterized here may give rise to novel HBx-targeting diagnostics and therapeutics for HBV- and HBx-related pathologies.
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Affiliation(s)
- Shuai Tao
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Department of Microbiology and Parasitology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Shaokun Pan
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Department of Microbiology and Parasitology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.,National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Chenjian Gu
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Department of Microbiology and Parasitology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Lili Wei
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Department of Microbiology and Parasitology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Ning Kang
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Department of Microbiology and Parasitology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Youhua Xie
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Department of Microbiology and Parasitology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.
| | - Jing Liu
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), Department of Microbiology and Parasitology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China. .,Key Laboratory of Medical Epigenetics and Metabolism, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.
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8
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Charostad J, Astani A, Goudarzi H, Faghihloo E. DNA methyltransferases in virus-associated cancers. Rev Med Virol 2018; 29:e2022. [PMID: 30511446 DOI: 10.1002/rmv.2022] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Revised: 10/24/2018] [Accepted: 10/24/2018] [Indexed: 12/19/2022]
Abstract
Human tumor viruses are either casually linked or contribute in the development of human cancers. Viruses can stimulate oncogenesis through affecting diverse biological pathways in human cells. Growing data have demonstrated frequent involvement of one of the most characteristic parts of cellular epigenetic machinery, DNA methylation, in the oncogenesis. DNA methylation of cellular genes is catalyzed by DNA methyltransferases (DNMTs) as a key effector enzyme in this process. Dysregulation of DNMTs can cause aberrant gene methylation in promoter of cancer-related genes including tumor suppressor genes, resulting in gene silencing. In this regard, the role of tumor viruses is remarkable. Here, in this review, we used published information to elucidate whether tumor viruses are able to manipulate DNMT regulation, and if so, what are its consequences in the process of oncogenesis. This essay also aims to shed light on which cellular pathways have been engaged by viruses to induce DNMTs.
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Affiliation(s)
- Javad Charostad
- Department of Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Akram Astani
- Zoonotic Diseases Research Center, School of Public Health, Sahid Sadoughi University of Medical Sciences, Yazd, Iran.,Department of Microbiology, Shahid Sadoghi University of Medical Science, Yazd, Iran
| | - Hossein Goudarzi
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ebrahim Faghihloo
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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9
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Identification of Retinoic Acid Receptor Agonists as Potent Hepatitis B Virus Inhibitors via a Drug Repurposing Screen. Antimicrob Agents Chemother 2018; 62:AAC.00465-18. [PMID: 30224536 DOI: 10.1128/aac.00465-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/05/2018] [Indexed: 12/14/2022] Open
Abstract
Currently available therapies for chronic hepatitis B virus (HBV) infection can efficiently reduce viremia but induce hepatitis B surface antigen (HBsAg) loss in very few patients; also, these therapies do not greatly affect the viral covalently closed circular DNA (cccDNA). To discover new agents with complementary anti-HBV effects, we performed a drug repurposing screen of 1,018 Food and Drug Administration (FDA)-approved compounds using HBV-infected primary human hepatocytes (PHH). Several compounds belonging to the family of retinoic acid receptor (RAR) agonists were identified that reduced HBsAg levels in a dose-dependent manner without significant cytotoxicity. Among them, tazarotene exhibited the most potent anti-HBV effect, with a half-maximal inhibitory concentration (IC50) for HBsAg of less than 30 nM in PHH. The inhibitory effect was also observed in HBV-infected differentiated HepaRG (dHepaRG) models, but not in HepG2.215 cells, and HBV genotypes A to D were similarly inhibited. Tazarotene was further demonstrated to repress HBV cccDNA transcription, as determined by the levels of HBV cccDNA and RNAs and the activation of HBV promoters. Moreover, RNA sequence analysis showed that tazarotene did not induce an interferon response but altered the expression of a number of genes associated with RAR and metabolic pathways. Inhibition of RARβ, but not RARα, by a specific antagonist significantly attenuated the anti-HBV activity of tazarotene, suggesting that tazarotene inhibits HBV in part through RARβ. Finally, a synergistic effect of tazarotene and entecavir on HBV DNA levels was observed. Therefore, RAR agonists as represented by tazarotene were identified as potential novel anti-HBV agents.
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10
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Lu Z. The function of HBx in HBV-induced hepatocellular carcinoma. INFECTION INTERNATIONAL 2018. [DOI: 10.1515/ii-2017-0157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AbstractHepatocellular carcinoma (HCC) is the second cause cancer death in the world. HCC is frequently diagnosed at advanced stages with intrahepatic metstasis or vascular invasion and has a poor prognosis with a high mortality rate. In the world, hepatitis B virus (HBV) caused over 50% HCC, making it the most common carcinogen after tobacco. Notably, accumulating evidence suggests HBV X gene (HBx) play an important role in tumorigenesis of HBV-related HCC. In this review, we will summarize the functions of HBx proteins in tumorigenesis and discuss their potential implications in cancer therapy.
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Affiliation(s)
- Zhaoliang Lu
- The First Affiliated Hospital, Biomedical Translational Research Institute, Jinan University, 601 West Huangpu Avenue, Guangzhou, Guangdong 510632, China
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11
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DNA Tumor Virus Regulation of Host DNA Methylation and Its Implications for Immune Evasion and Oncogenesis. Viruses 2018; 10:v10020082. [PMID: 29438328 PMCID: PMC5850389 DOI: 10.3390/v10020082] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 02/07/2018] [Accepted: 02/07/2018] [Indexed: 12/11/2022] Open
Abstract
Viruses have evolved various mechanisms to evade host immunity and ensure efficient viral replication and persistence. Several DNA tumor viruses modulate host DNA methyltransferases for epigenetic dysregulation of immune-related gene expression in host cells. The host immune responses suppressed by virus-induced aberrant DNA methylation are also frequently involved in antitumor immune responses. Here, we describe viral mechanisms and virus–host interactions by which DNA tumor viruses regulate host DNA methylation to evade antiviral immunity, which may contribute to the generation of an immunosuppressive microenvironment during cancer development. Recent trials of immunotherapies have shown promising results to treat multiple cancers; however, a significant number of non-responders necessitate identifying additional targets for cancer immunotherapies. Thus, understanding immune evasion mechanisms of cancer-causing viruses may provide great insights for reversing immune suppression to prevent and treat associated cancers.
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12
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Choi JH, Jeong H, Jang KL. Hepatitis B virus X protein suppresses all-trans retinoic acid-induced apoptosis in human hepatocytes by repressing p14 expression via DNA methylation. J Gen Virol 2017; 98:2786-2798. [PMID: 29068287 DOI: 10.1099/jgv.0.000958] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
All-trans retinoic acid (ATRA), the most biologically active metabolite of vitamin A, is known to activate p14 expression via promoter hypermethylation to induce p53-dependent apoptosis in human hepatocytes. In this study, we found that the oncogenic hepatitis B virus (HBV) X protein (HBx) of HBV, derived from both overexpression and 1.2-mer replicon systems, suppresses ATRA-induced apoptosis in p53-positive human hepatocytes. For this effect, HBx upregulated both protein and enzyme activity levels of DNA methyltransferase 1, 3a and 3b, in the presence of ATRA and thereby inhibited p14 expression via promoter hypermethylation, resulting in inactivation of the p14-mouse double minute 2 pathway and subsequent downregulation of p53 levels. As a result, HBx was able to impair the potential of ATRA to activate apoptosis-related molecules, including Bax, p53-upregulated modulator of apoptosis, caspase-9, caspase-3 and poly (ADP-ribose) polymerase. In conclusion, the present study provides a new oncogenic action mechanism of HBx, namely by suppressing the anticancer potential of ATRA to induce p53-dependent apoptosis in HBV-infected hepatocytes.
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Affiliation(s)
- Jung-Hye Choi
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Hyerin Jeong
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Kyung Lib Jang
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea
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13
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Interference of Apoptosis by Hepatitis B Virus. Viruses 2017; 9:v9080230. [PMID: 28820498 PMCID: PMC5580487 DOI: 10.3390/v9080230] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 08/07/2017] [Accepted: 08/10/2017] [Indexed: 12/16/2022] Open
Abstract
Hepatitis B virus (HBV) causes liver diseases that have been a consistent problem for human health, leading to more than one million deaths every year worldwide. A large proportion of hepatocellular carcinoma (HCC) cases across the world are closely associated with chronic HBV infection. Apoptosis is a programmed cell death and is frequently altered in cancer development. HBV infection interferes with the apoptosis signaling to promote HCC progression and viral proliferation. The HBV-mediated alteration of apoptosis is achieved via interference with cellular signaling pathways and regulation of epigenetics. HBV X protein (HBX) plays a major role in the interference of apoptosis. There are conflicting reports on the HBV interference of apoptosis with the majority showing inhibition of and the rest reporting induction of apoptosis. In this review, we described recent studies on the mechanisms of the HBV interference with the apoptosis signaling during the virus infection and provided perspective.
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14
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Hepatoepigenetic Alterations in Viral and Nonviral-Induced Hepatocellular Carcinoma. BIOMED RESEARCH INTERNATIONAL 2016; 2016:3956485. [PMID: 28105421 PMCID: PMC5220417 DOI: 10.1155/2016/3956485] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 11/30/2016] [Indexed: 12/13/2022]
Abstract
Hepatocellular carcinoma (HCC) is a major public health concern and one of the leading causes of tumour-related deaths worldwide. Extensive evidence endorses that HCC is a multifactorial disease characterised by hepatic cirrhosis mostly associated with chronic inflammation and hepatitis B/C viral infections. Interaction of viral products with the host cell machinery may lead to increased frequency of genetic and epigenetic aberrations that cause harmful alterations in gene transcription. This may provide a progressive selective advantage for neoplastic transformation of hepatocytes associated with phenotypic heterogeneity of intratumour HCC cells, thus posing even more challenges in HCC treatment development. Epigenetic aberrations involving DNA methylation, histone modifications, and noncoding miRNA dysregulation have been shown to be intimately linked with and play a critical role in tumour initiation, progression, and metastases. The current review focuses on the aberrant hepatoepigenetics events that play important roles in hepatocarcinogenesis and their utilities in the development of HCC therapy.
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Kim H, Lee SA, Kim BJ. X region mutations of hepatitis B virus related to clinical severity. World J Gastroenterol 2016; 22:5467-5478. [PMID: 27350725 PMCID: PMC4917607 DOI: 10.3748/wjg.v22.i24.5467] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 05/17/2016] [Accepted: 06/02/2016] [Indexed: 02/06/2023] Open
Abstract
Chronic hepatitis B virus (HBV) infection remains a major health problem, with more than 240 million people chronically infected worldwide and potentially 650000 deaths per year due to advanced liver diseases including liver cirrhosis and hepatocellular carcinoma (HCC). HBV-X protein (HBx) contributes to the biology and pathogenesis of HBV via stimulating virus replication or altering host gene expression related to HCC. The HBV X region contains only 465 bp encoding the 16.5 kDa HBx protein, which also contains several critical cis-elements such as enhancer II, the core promoter and the microRNA-binding region. Thus, mutations in this region may affect not only the HBx open reading frame but also the overlapped cis-elements. Recently, several types of HBx mutations significantly associated with clinical severity have been described, although the functional mechanism in most of these cases remains unsolved. This review article will mainly focus on the HBx mutations proven to be significantly related to clinical severity via epidemiological studies.
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16
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Ancey PB, Testoni B, Gruffaz M, Cros MP, Durand G, Le Calvez-Kelm F, Durantel D, Herceg Z, Hernandez-Vargas H. Genomic responses to hepatitis B virus (HBV) infection in primary human hepatocytes. Oncotarget 2015; 6:44877-91. [PMID: 26565721 PMCID: PMC4792598 DOI: 10.18632/oncotarget.6270] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/14/2015] [Indexed: 01/04/2023] Open
Abstract
Viral infections are able to modify the host's cellular programs, with DNA methylation being a biological intermediate in this process. The extent to which viral infections deregulate gene expression and DNA methylation is not fully understood. In the case of Hepatitis B virus (HBV), there is evidence for an interaction between viral proteins and the host DNA methylation machinery. We studied the ability of HBV to modify the host transcriptome and methylome, using naturally infected primary human hepatocytes to better mimic the clinical setting.Gene expression was especially sensitive to culture conditions, independently of HBV infection. However, we identified non-random changes in gene expression and DNA methylation occurring specifically upon HBV infection. There was little correlation between expression and methylation changes, with transcriptome being a more sensitive marker of time-dependent changes induced by HBV. In contrast, a set of differentially methylated sites appeared early and were stable across the time course experiment. Finally, HBV-induced DNA methylation changes were defined by a specific chromatin context characterized by CpG-poor regions outside of gene promoters.These data support the ability of HBV to modulate host cell expression and methylation programs. In addition, it may serve as a reference for studies addressing the genome-wide consequences of HBV infection in human hepatocytes.
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Affiliation(s)
- Pierre-Benoit Ancey
- Epigenetics Group, International Agency for Research on Cancer (IARC), Lyon, France
| | - Barbara Testoni
- INSERM U1052, Molecular Physiopathology and New Treatments of Viral Hepatitis, Centre de Recherche en Cancérologie (CRCL), Lyon, France
| | - Marion Gruffaz
- INSERM U1052, Molecular Physiopathology and New Treatments of Viral Hepatitis, Centre de Recherche en Cancérologie (CRCL), Lyon, France
| | - Marie-Pierre Cros
- Epigenetics Group, International Agency for Research on Cancer (IARC), Lyon, France
| | - Geoffroy Durand
- Genetic Cancer Susceptibility Group, International Agency for Research on Cancer (IARC), Lyon, France
| | - Florence Le Calvez-Kelm
- Genetic Cancer Susceptibility Group, International Agency for Research on Cancer (IARC), Lyon, France
| | - David Durantel
- INSERM U1052, Molecular Physiopathology and New Treatments of Viral Hepatitis, Centre de Recherche en Cancérologie (CRCL), Lyon, France
| | - Zdenko Herceg
- Epigenetics Group, International Agency for Research on Cancer (IARC), Lyon, France
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Minarovits J, Demcsák A, Banati F, Niller HH. Epigenetic Dysregulation in Virus-Associated Neoplasms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 879:71-90. [DOI: 10.1007/978-3-319-24738-0_4] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Niller HH, Ay E, Banati F, Demcsák A, Takacs M, Minarovits J. Wild type HBx and truncated HBx: Pleiotropic regulators driving sequential genetic and epigenetic steps of hepatocarcinogenesis and progression of HBV-associated neoplasms. Rev Med Virol 2015; 26:57-73. [PMID: 26593760 DOI: 10.1002/rmv.1864] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 09/30/2015] [Accepted: 10/15/2015] [Indexed: 12/23/2022]
Abstract
Hepatitis B virus (HBV) is one of the causative agents of hepatocellular carcinoma. The molecular mechanisms of tumorigenesis are complex. One of the host factors involved is apparently the long-lasting inflammatory reaction which accompanies chronic HBV infection. Although HBV lacks a typical viral oncogene, the HBx gene encoding a pleiotropic regulatory protein emerged as a major player in liver carcinogenesis. Here we review the tumorigenic functions of HBx with an emphasis on wild type and truncated HBx variants, and their role in the transcriptional dysregulation and epigenetic reprogramming of the host cell genome. We suggest that HBx acquired by the HBV genome during evolution acts like a cellular proto-onc gene that is activated by deletion during hepatocarcinogenesis. The resulting viral oncogene (v-onc gene) codes for a truncated HBx protein that facilitates tumor progression. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Hans Helmut Niller
- Institute for Medical Microbiology and Hygiene, University of Regensburg, Regensburg, Germany
| | - Eva Ay
- Department of Retrovirology, National Center for Epidemiology, Budapest, Hungary
| | - Ferenc Banati
- RT-Europe Nonprofit Research Center, Mosonmagyarovar, Hungary
| | - Anett Demcsák
- University of Szeged, Faculty of Dentistry, Department of Oral Biology and Experimental Dental Research, Szeged, Hungary
| | - Maria Takacs
- Division of Virology, National Center for Epidemiology, Budapest, Hungary
| | - Janos Minarovits
- University of Szeged, Faculty of Dentistry, Department of Oral Biology and Experimental Dental Research, Szeged, Hungary
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Zhang C, Li G. Role of alpha-fetoprotein in hepatitis B virus-induced hepatocellular carcinoma: Prospect in clinical application. Shijie Huaren Xiaohua Zazhi 2015; 23:3171-3181. [DOI: 10.11569/wcjd.v23.i20.3171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Mammalian alpha-fetoprotein (AFP) as a fetal specific alpha-globulin that has been used as a serum fetal defect/tumor marker for diagnosis and prediction of liver disease. Over the past decade, research indicates that AFP as an intracellular signal molecule is not only a biomarker but also interacts with hepatitis B virus (HBV) and hepatitis B virus protein x and plays multifarious roles in the development of hepatocellular carcinoma, especially in HBV-induced liver cancer.
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20
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Ryu SH, Jang MK, Kim WJ, Lee D, Chung YH. Metastatic tumor antigen in hepatocellular carcinoma: golden roads toward personalized medicine. Cancer Metastasis Rev 2014; 33:965-80. [PMID: 25325987 DOI: 10.1007/s10555-014-9522-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hepatocellular carcinoma (HCC), a prototype of hypervascular tumors, is one of the most common malignancies in the world, especially hyperendemic in the Far East where chronic hepatitis B virus (HBV) infection is highly prevalent. It is characterized by the clinical feature of a poor prognosis or a high mortality due to its already far advanced stages at diagnosis. It is so multifactorial that hepatocarcinogenesis cannot be explained by a single molecular mechanism. To date, a number of pathways have been known to contribute to the development, growth, angiogenesis, and even metastasis of HCC. Among the various factors, metastatic tumor antigens (MTAs) or metastasis-associated proteins have been vigorously investigated as an intriguing target in the field of hepatocarcinogenesis. According to recent studies including ours, MTAs are not only involved in the HCC development and growth (molecular carcinogenesis), but also closely associated with the post-operative recurrence and a poor prognosis or a worse response to post-operative anti-cancer therapy (clinical significance). Herein, we review MTAs in light of their essential structure, functions, and molecular mechanism in hepatocarcinogenesis. We will also focus in detail on the interaction between hepatitis B x protein (HBx) of HBV and MTA in order to clarify the HBV-associated HCC development. Finally, we will discuss the prognostic significance and clinical application of MTA in HCC. We believe that this review will help clinicians to understand the meaning and use of the detection of MTA in order to more effectively manage their HCC patients.
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Affiliation(s)
- Soo Hyung Ryu
- Department of Internal Medicine, Inje University College of Medicine, Seoul Paik Hospital, Seoul, South Korea
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Ali A, Abdel-Hafiz H, Suhail M, Al-Mars A, Zakaria MK, Fatima K, Ahmad S, Azhar E, Chaudhary A, Qadri I. Hepatitis B virus, HBx mutants and their role in hepatocellular carcinoma. World J Gastroenterol 2014; 20:10238-10248. [PMID: 25132741 PMCID: PMC4130832 DOI: 10.3748/wjg.v20.i30.10238] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Revised: 04/30/2014] [Accepted: 05/26/2014] [Indexed: 02/06/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is one of the leading causes of death induced by cancer in the modern world and majority of the cases are related to chronic hepatitis B virus (HBV) infection. HBV-encoded X protein (HBx) is known to play a pivotal role in the pathogenesis of viral induced HCC. HBx is a multifunctional protein of 17 kDa which modulates several cellular processes by direct or indirect interaction with a repertoire of host factors resulting in HCC. HBX might interfere with several cellular processes such as oxidative stress, DNA repair, signal transduction, transcription, protein degradation, cell cycle progression and apoptosis. A number of reports have indicated that HBx is one of the most common viral ORFs that is often integrated into the host genome and its sequence variants play a crucial role in HCC. By mutational or deletion analysis it was shown that carboxy terminal of HBx has a likely role in protein-protein interactions, transcriptional transactivation, DNA repair, cell, signaling and pathogenesis of HCC. The accumulated evidence thus far suggests that it is difficult to understand the mechanistic nature of HBx associated HCC, and HBx mediated transcriptional transactivation and signaling pathways may be a major determinant. This article addresses the role of HBx in the development of HCC with particular emphasis on HBx mutants and their putative targets.
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Mao K, Zhang J, He C, Xu K, Liu J, Sun J, Wu G, Tan C, Zeng Y, Wang J, Xiao Z. Restoration of miR-193b sensitizes Hepatitis B virus-associated hepatocellular carcinoma to sorafenib. Cancer Lett 2014; 352:245-52. [PMID: 25034398 DOI: 10.1016/j.canlet.2014.07.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 06/29/2014] [Accepted: 07/03/2014] [Indexed: 12/12/2022]
Abstract
BACKGROUND Chronic infection with Hepatitis B virus (HBV) is the major risk factor of Hepatocellular Carcinoma (HCC). This study is to explore the mechanism of sorafenib resistance and find an effective strategy to sensitize HBV-associated HCC to sorafenib. METHODS Cytotoxicity to sorafenib was evaluated in HBV-positive/negative HCC cell lines. Expression of miR-193b and myeloid cell leukemia-1 (Mcl-1) protein were assessed by Q-PCR, in situ hybridization and western blot, immunohistochemistry, respectively. A luciferase reporter of Mcl-1 3'-UTR was used for validation as a target of miR-193b. Cell apoptosis was measured by flow cytometry, caspase-3 activity assay and DAPI staining. RESULT The IC50 to sorafenib was significantly higher in HBV-positive HCC cells than those without HBV infection. Significant downregulation of miR-193b and a higher level of Mcl-1 were observed in HBV-positive HCC cells and tissues. The activity of Mcl-1 3'-UTR reporter was inhibited by co-transfection with miR-193b mimic. Restoring the expression of miR-193b sensitized HBV-associated HCC cells to sorafenib treatment and facilitated sorafenib-induced apoptosis. CONCLUSIONS Modulation of miRNAs expression might be a potential way to enhance response to sorafenib in HBV-associated HCC.
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Affiliation(s)
- Kai Mao
- Department of Hepatobiliary Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Jianlong Zhang
- Department of Hepatobiliary Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Chuanchao He
- Department of Hepatobiliary Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Kang Xu
- Department of Hepatobiliary Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Jieqiong Liu
- Department of Breast Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Jian Sun
- Department of Hepatobiliary Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Gang Wu
- Department of Hepatobiliary Surgery, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China
| | - Cui Tan
- Department of Pathology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Yunjie Zeng
- Department of Pathology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Jie Wang
- Department of Hepatobiliary Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
| | - Zhiyu Xiao
- Department of Hepatobiliary Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
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23
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Feitelson MA, Bonamassa B, Arzumanyan A. The roles of hepatitis B virus-encoded X protein in virus replication and the pathogenesis of chronic liver disease. Expert Opin Ther Targets 2014; 18:293-306. [PMID: 24387282 DOI: 10.1517/14728222.2014.867947] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Hepatitis B virus (HBV) is a major cause of chronic liver disease (CLD) and hepatocellular carcinoma (HCC) worldwide. More than 350 million people are at risk for HCC, and with few treatment options available, therapeutic approaches to targets other than the virus polymerase will be needed. This review suggests that the HBV-encoded X protein, HBx, would be an outstanding target because it contributes to the biology and pathogenesis of HBV in three fundamental ways. AREAS COVERED First, HBx is a trans-activating protein that stimulates virus gene expression and replication, thereby promoting the development and persistence of the carrier state. Second, HBx partially blocks the development of immune responses that would otherwise clear the virus, and protects infected hepatocytes from immune-mediated destruction. Thus, HBx contributes to the development of CLD without virus clearance. Third, HBx alters patterns of host gene expression that make possible the emergence of HCC. The selected literature cited is from the National Library of Medicine (Pubmed and Medline). EXPERT OPINION Understanding the mechanisms, whereby HBx supports virus replication and promotes pathogenesis, suggests that HBx will be an important therapeutic target against both virus replication and CLD aimed at the chemoprevention of HCC.
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Affiliation(s)
- Mark A Feitelson
- Temple University, College of Science and Technology, Department of Biology , Room 409 BioLife Science Building, 1900 N. 12th Street, Philadelphia, PA 19122 , USA +1 215 204 8434 ; +1 215 204 8359 ;
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24
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Spaniel C, Honda M, Selitsky SR, Yamane D, Shimakami T, Kaneko S, Lanford RE, Lemon SM. microRNA-122 abundance in hepatocellular carcinoma and non-tumor liver tissue from Japanese patients with persistent HCV versus HBV infection. PLoS One 2013; 8:e76867. [PMID: 24130799 PMCID: PMC3793926 DOI: 10.1371/journal.pone.0076867] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Accepted: 08/29/2013] [Indexed: 02/06/2023] Open
Abstract
Mechanisms of hepatic carcinogenesis in chronic hepatitis B and hepatitis C are incompletely defined but often assumed to be similar and related to immune-mediated inflammation. Despite this, several studies hint at differences in expression of miR-122, a liver-specific microRNA with tumor suppressor properties, in hepatocellular carcinoma (HCC) associated with hepatitis B virus (HBV) versus hepatitis C virus (HCV) infection. Differences in the expression of miR-122 in these cancers would be of interest, as miR-122 is an essential host factor for HCV but not HBV replication. To determine whether the abundance of miR-122 in cancer tissue is influenced by the nature of the underlying virus infection, we measured miR-122 by qRT-PCR in paired tumor and non-tumor tissues from cohorts of HBV- and HCV-infected Japanese patients. miR-122 abundance was significantly reduced from normal in HBV-associated HCC, but not in liver cancer associated with HCV infection. This difference was independent of the degree of differentiation of the liver cancer. Surprisingly, we also found significant differences in miR-122 expression in non-tumor tissue, with miR-122 abundance reduced from normal in HCV- but not HBV-infected liver. Similar differences were observed in HCV- vs. HBV-infected chimpanzees. Among HCV-infected Japanese subjects, reductions in miR-122 abundance in non-tumor tissue were associated with a single nucleotide polymorphism near the IL28B gene that predicts poor response to interferon-based therapy (TG vs. TT genotype at rs8099917), and correlated negatively with the abundance of multiple interferon-stimulated gene transcripts. Reduced levels of miR-122 in chronic hepatitis C thus appear to be associated with endogenous interferon responses to the virus, while differences in miR-122 expression in HCV- versus HBV-associated HCC likely reflect virus-specific mechanisms contributing to carcinogenesis. The continued expression of miR-122 in HCV-associated HCC may signify an important role for HCV replication late in the progression to malignancy.
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Affiliation(s)
- Carolyn Spaniel
- Departments of Medicine and Microbiology & Immunology and the Lineberger Comprehensive Cancer Center, the University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Masao Honda
- Department of Gastroenterology, Kanazawa University Graduate School of Medicine, Takara-Machi, Kanazawa, Japan
| | - Sara R. Selitsky
- Departments of Medicine and Microbiology & Immunology and the Lineberger Comprehensive Cancer Center, the University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Genetics, the University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Daisuke Yamane
- Departments of Medicine and Microbiology & Immunology and the Lineberger Comprehensive Cancer Center, the University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Tetsuro Shimakami
- Department of Gastroenterology, Kanazawa University Graduate School of Medicine, Takara-Machi, Kanazawa, Japan
| | - Shuichi Kaneko
- Department of Gastroenterology, Kanazawa University Graduate School of Medicine, Takara-Machi, Kanazawa, Japan
| | - Robert E. Lanford
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, Texas, United States of America
| | - Stanley M. Lemon
- Departments of Medicine and Microbiology & Immunology and the Lineberger Comprehensive Cancer Center, the University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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Lee H, Sohn JB, Kim SS, Jang KL. DNA methyltransferase inhibitor assay system based on the HBx-induced DNA methylation of E-cadherin. Biochem Biophys Res Commun 2013; 438:540-5. [PMID: 23906757 DOI: 10.1016/j.bbrc.2013.07.094] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 07/23/2013] [Indexed: 01/01/2023]
Abstract
We here report a simple assay system for DNA methyltransferase (DNMT) inhibitors based on the HBx-induced DNA methylation of E-cadherin. A stable cell line named G1 was generated by co-transfecting E-cadherin luciferase reporter and HBx-expression plasmid into HepG2 cells. Treatment of G1 cells with DNMT inhibitors, 5-azacytidine, 5-aza-2'-deoxycytidine, and procainamaid, dose-dependently inhibited DNA methylation of E-cadherin promoter in the reporter, resulting in up-regulation of luciferase levels and its enzyme activity. Treatment with all-trans retinoic acid that is known to inhibit DNMT expression, also induced similar effects. Our system can be useful for development of epi-drugs targeting DNA methylation in malignancies.
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Affiliation(s)
- Hyehyeon Lee
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 609-735, Republic of Korea
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26
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Hepatitis C virus Core protein overcomes all-trans retinoic acid-induced cell growth arrest by inhibiting retinoic acid receptor-β2 expression via DNA methylation. Cancer Lett 2013; 335:372-9. [DOI: 10.1016/j.canlet.2013.02.057] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 02/21/2013] [Accepted: 02/24/2013] [Indexed: 02/08/2023]
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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: 6.3] [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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Hepatitis B virus X protein-induced aberrant epigenetic modifications contributing to human hepatocellular carcinoma pathogenesis. Mol Cell Biol 2013; 33:2810-6. [PMID: 23716588 DOI: 10.1128/mcb.00205-13] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hepatocellular carcinoma (HCC) remains one of the most prevalent malignant diseases worldwide, and the majority of cases are related to hepatitis B virus (HBV) infection. Interactions between the HBV-encoded X (HBx) protein and host factors are known to play major roles in the onset and progression of HBV-related HCC. These dynamic molecular mechanisms are extremely complex and lead to prominent changes in the host genetic and epigenetic architecture. This review summarizes the current knowledge about HBx-induced epigenetic changes, including aberrations in DNA methylation, histone modifications, and microRNA expression, and their roles in HBV-infected liver cells and HBV-related HCC. Moreover, the HBx-mediated epigenetic control of HBV covalently closed circular DNA (cccDNA) is also discussed. Although this field of study is relatively new, the accumulated evidence has indicated that the epigenetic events induced by HBx play important roles in the development of HBV-related HCC. Ongoing research will help to identify practical applications of the HBV-related epigenetic signatures as biomarkers for early HCC detection or as potential targets to prevent and treat HBV-related HCC.
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Epigenetic control of metastasis-associated protein 1 gene expression by hepatitis B virus X protein during hepatocarcinogenesis. Oncogenesis 2012; 1:e25. [PMID: 23552838 PMCID: PMC3503295 DOI: 10.1038/oncsis.2012.26] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Expression of metastasis-associated protein 1 (MTA1) gene correlates with the degree of invasion and metastasis in hepatocellular carcinoma (HCC). Expression of MTA1 is induced by hepatitis B virus X protein (HBx); however, little is known about the transcriptional regulation of MTA1 gene expression. Here, we report that the 5′-flanking region of the human MTA1 promoter contains two CpG islands. Transient expression of HBx in Chang liver cells increased the methylation of the CpG island1 from 18 to 49% when measured by bisulfite-modified direct sequencing. Chromatin immunoprecipitation showed that HBx recruited DNA methyltransferase 3a (DNMT3a) and DNMT3b to the CpG island1. In silico analysis of CpG island1 predicted the existence of putative p53-binding sequences. p53 was pulled down by a DNA probe encoding the p53-binding sequences but not by the methylated DNA probe. The mouse MTA1 promoter also contains a CpG island encoding a p53-binding sequence of which p53 binding was decreased in the presence of HBx, and the expression of MTA1 and DNMT3 was increased in the liver of HBx-transgenic mice. Comparison of MTA1 and DNMT3a expression in the human normal liver and HCC specimens produced a significant correlation coefficient >0.5 (r=0.5686, P=0.0001) for DNMT3a, and a marginally significant coefficient (r=0.3162, P=0.0103) for DNMT3b. These data show that HBx induces methylation of CpG island in the MTA1 promoter, which interferes with DNA binding of p53 in the specific DNA region. This result may explain the molecular mechanism responsible for the induction of MTA1 gene expression by HBx.
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Lim JS, Park SH, Jang KL. All-trans retinoic acid induces cellular senescence by up-regulating levels of p16 and p21 via promoter hypomethylation. Biochem Biophys Res Commun 2011; 412:500-5. [DOI: 10.1016/j.bbrc.2011.07.130] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 07/30/2011] [Indexed: 01/08/2023]
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Abstract
Chronic hepatitis B virus (HBV) infection has been identified as a major risk factor in hepatocellular carcinoma (HCC), which is one of the most common cancers worldwide. The pathogenesis of HBV-mediated hepatocarcinogenesis is, however, incompletely understood. Evidence suggests that the HBV X protein (HBx) plays a crucial role in HCC development. HBx is a multifunctional regulator that modulates transcription, signal transduction, cell cycle progression, apoptosis, protein degradation pathways, and genetic stability through interaction with host factors. This review describes the current state of knowledge of the molecular pathogenesis of HBV-induced HCC, with a focus on the role of HBx in hepatocarcinogenesis.
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Affiliation(s)
- Sue-Ann Ng
- University of New South Wales, Sydney, Australia.
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Park SH, Lim JS, Jang KL. All-trans retinoic acid induces cellular senescence via upregulation of p16, p21, and p27. Cancer Lett 2011; 310:232-9. [PMID: 21803488 DOI: 10.1016/j.canlet.2011.07.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 07/04/2011] [Accepted: 07/07/2011] [Indexed: 11/19/2022]
Abstract
We here present a new anti-tumor mechanism of all-trans retinoic acid (ATRA). ATRA induced several biomarkers of cellular senescence including irreversible G1 arrest, morphological changes, senescence-associated β-galactosidase, and heterochromatin foci in HepG2 cells. ATRA also upregulated levels of p16, p21, and p27 which lead to activation of Rb and subsequent inactivation of E2F1. These effects were abolished by the RNA interference-mediated silencing of p16, p21, and p27. Moreover, ATRA failed to induce cellular senescence in Huh7 and HCT116, in which p16, p21, and p27 were not upregulated by ATRA, confirming that ATRA induces cellular senescence via upregulation of p16, p21, and p27.
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Affiliation(s)
- Sun-Hye Park
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 609-735, Republic of Korea
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Park SH, Jung JK, Lim JS, Tiwari I, Jang KL. Hepatitis B virus X protein overcomes all-trans retinoic acid-induced cellular senescence by downregulating levels of p16 and p21 via DNA methylation. J Gen Virol 2011; 92:1309-1317. [PMID: 21325480 DOI: 10.1099/vir.0.029512-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Despite current molecular evidence suggesting that hepatitis B virus (HBV) X protein (HBx) plays an important role during HBV-mediated hepatocarcinogenesis, the detailed mechanism is still controversial. Here, it was shown that HBx overcomes cellular senescence provoked by all-trans retinoic acid (ATRA) in HepG2 cells, as demonstrated by the impaired induction of irreversible G(1) arrest and senescence-associated β-galactosidase activity by ATRA in the presence of HBx. The anti-senescence effect of HBx was also observed in another human hepatoma cell line, Hep3B, but not in Huh-7 cells in which the p16 and p21 proteins are absent. In addition, HBx suppressed ATRA-mediated induction of p16 and p21 in HepG2 cells via promoter hypermethylation, resulting in inactivation of retinoblastoma protein. Furthermore, the ability of HBx to overcome ATRA-induced cellular senescence almost completely disappeared when the levels of p16 and p21 in the HBx-expressing cells became similar to those in the control cells by complementation in the former by exogenous expression, knockdown of their expression in the latter using specific small interfering RNA or treatment with a DNA methylation inhibitor, 5-Aza-2'-deoxycytidine. These results suggest that HBx executes its potential by downregulating levels of p16 and p21 via DNA methylation. As cellular senescence is a tumour-suppression process, the present study provides a new strategy by which HBV promotes hepatocarcinogenesis.
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Affiliation(s)
- Sun-Hye Park
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 609-735, Republic of Korea
| | - Jin Kyu Jung
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 609-735, Republic of Korea
| | - Joo Song Lim
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 609-735, Republic of Korea
| | - Indira Tiwari
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 609-735, Republic of Korea
| | - Kyung Lib Jang
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 609-735, Republic of Korea
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Kew MC. Hepatitis B virus x protein in the pathogenesis of hepatitis B virus-induced hepatocellular carcinoma. J Gastroenterol Hepatol 2011; 26 Suppl 1:144-52. [PMID: 21199526 DOI: 10.1111/j.1440-1746.2010.06546.x] [Citation(s) in RCA: 205] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Currently available evidence supports a role for the hepatitis B virus (HBV) x gene and protein in the pathogenesis of HBV-induced hepatocellular carcinoma (HCC). HBx gene is often included, and remains functionally active, in the HBV DNA that is frequently integrated into cellular DNA during hepatocellular carcinogenesis. HBx protein promotes cell cycle progression, inactivates negative growth regulators, and binds to and inhibits the expression of p53 tumour suppressor gene and other tumour suppressor genes and senescence-related factors. However, the molecular mechanisms responsible for HBx protein-induced HCC remain uncertain. Only some of the more fully documented or more recently recognised mechanisms are reviewed. During recent years evidence has accumulated that HBx protein modulates transcription of methyl transferases, causing regional hypermethylation of DNA that results in silencing of tumour suppressor genes, or global hypomethylation that results in chromosomal instability, thereby playing a role in hepatocarcinogenesis. HBx protein has both anti-apoptotic and pro-apoptotic actions, apparently contradictory effects that have yet to be explained. Particularly important among the anti-apoptotic properties is inhibition of p53. Recent experimental observations suggest that HBx protein may increase the expression of TERT and telomerase activity, prolonging the life-span of hepatocytes and contributing to malignant transformation. The protein also interferes with nucleotide excision repair through both p53-dependent and p53- independent mechanisms. Carboxy-terminal truncated HBx protein loses its inhibitory effects on cell proliferation and pro-apoptotic properties, and it may enhance the protein's ability to transform oncogenes. Dysregulation of IGF-II enhances proliferation and anti-apoptotic effects of oncogenes, resulting in uncontrolled cell growth.
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Affiliation(s)
- Michael C Kew
- Department of Medicine, University of Cape Town, Groote Schuur Hospital, South Africa.
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