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Medhat A, Arzumanyan A, Feitelson MA. Hepatitis B x antigen (HBx) is an important therapeutic target in the pathogenesis of hepatocellular carcinoma. Oncotarget 2021; 12:2421-2433. [PMID: 34853663 PMCID: PMC8629409 DOI: 10.18632/oncotarget.28077] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 09/04/2021] [Indexed: 12/12/2022] Open
Abstract
Hepatitis B virus (HBV) is a human pathogen that has infected an estimated two billion people worldwide. Despite the availability of highly efficacious vaccines, universal screening of the blood supply for virus, and potent direct acting anti-viral drugs, there are more than 250 million carriers of HBV who are at risk for the sequential development of hepatitis, fibrosis, cirrhosis and hepatocellular carcinoma (HCC). More than 800,000 deaths per year are attributed to chronic hepatitis B. Many different therapeutic approaches have been developed to block virus replication, and although effective, none are curative. These treatments have little or no impact upon the portions of integrated HBV DNA, which often encode the virus regulatory protein, HBx. Although given little attention, HBx is an important therapeutic target because it contributes importantly to (a) HBV replication, (b) in protecting infected cells from immune mediated destruction during chronic infection, and (c) in the development of HCC. Thus, the development of therapies targeting HBx, combined with other established therapies, will provide a functional cure that will target virus replication and further reduce or eliminate both the morbidity and mortality associated with chronic liver disease and HCC. Simultaneous targeting of all these characteristics underscores the importance of developing therapies against HBx.
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Affiliation(s)
- Arvin Medhat
- Department of Molecular Cell Biology, Azad University, North Unit, Tehran, Iran
| | - Alla Arzumanyan
- Department of Biology, College of Science and Technology, Temple University, Philadelphia, PA, USA
| | - Mark A Feitelson
- Department of Biology, College of Science and Technology, Temple University, Philadelphia, PA, USA
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2
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Yuan Y, Yang F, Wang Y, Guo Y. Factors associated with liver cancer prognosis after hepatectomy: A retrospective cohort study. Medicine (Baltimore) 2021; 100:e27378. [PMID: 34678864 PMCID: PMC8542119 DOI: 10.1097/md.0000000000027378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Accepted: 09/13/2021] [Indexed: 01/05/2023] Open
Abstract
This article was to investigate risk factors influencing liver cancer prognosis after hepatectomy.Patients undergoing hepatectomy after being diagnosed with liver cancer in Zhongshan Hospital Affiliated to Xiamen University were collected in the retrospective cohort study between January 2012 and December 2017, and divided into disease progression and non-progression groups based on their prognostic status. Univariate analysis was performed on the patients' baseline and laboratory test data, with multivariate logistic regression further conducted to investigate the independent risk factors for liver cancer progression after hepatectomy.Among the 288 subjects, 159 had adverse outcomes (death or cancer recurrence). Hepatitis B and high levels of aspartate aminotransferase, gamma-glutamyltransferase, alkaline phosphatase (ALP), direct bilirubin, and total bilirubin as well as low level of lymphocyte (LYM) were found to be associated with disease progression in the univariate analysis, and were introduced into the multivariate logistic regression. The results indicated that patients with high ALP level (odds ratio [OR] = 1.004, 95%CI: 1.002-1.007, P = .003) and with a history of hepatitis B (OR = 2.182, 95%CI: 1.165-4.086, P = .015) had a higher risk of liver cancer progression compared with those of lower ALP level and those without hepatitis B respectively, whereas the elevated level of LYM (OR = 0.710, 95%CI: 0.516-0.978, P = .034) had favorable progression.The elevated ALP level and a history of hepatitis B may increase the risk of death or cancer recurrence, whereas high LYM level may decrease poor progression among liver cancer patients after hepatectomy. More importance should be attached to the improvement of the liver function and treatment of hepatitis B to enable a better outcome for the patients.
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Affiliation(s)
- Yutao Yuan
- Department of Clinical Laboratory, Xiamen Haicang Hospital, Xiamen, P.R. China
| | - Fangnian Yang
- Department of Blood Transfusion, Zhongshan Hospital Affiliated to Xiamen University, Xiamen, P.R. China
| | - Yuanyuan Wang
- Department of Blood Transfusion, Zhongshan Hospital Affiliated to Xiamen University, Xiamen, P.R. China
| | - Yusong Guo
- Department of Blood Transfusion, Zhongshan Hospital Affiliated to Xiamen University, Xiamen, P.R. China
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3
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Humanized Mouse Models for the Study of Hepatitis C and Host Interactions. Cells 2019; 8:cells8060604. [PMID: 31213010 PMCID: PMC6627916 DOI: 10.3390/cells8060604] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 06/09/2019] [Accepted: 06/13/2019] [Indexed: 12/11/2022] Open
Abstract
Hepatitis C virus (HCV) infection is commonly attributed as a major cause of chronic hepatotropic diseases, such as, steatosis, cirrhosis and hepatocellular carcinoma. As HCV infects only humans and primates, its narrow host tropism hampers in vivo studies of HCV-mammalian host interactions and the development of effective therapeutics and vaccines. In this context, we will focus our discussion on humanized mice in HCV research. Here, these humanized mice are defined as animal models that encompass either only human hepatocytes or both human liver and immune cells. Aspects related to immunopathogenesis, anti-viral interventions, drug testing and perspectives of these models for future HCV research will be discussed.
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Song F, Wei M, Wang J, Liu Y, Guo M, Li X, Luo J, Zhou J, Wang M, Guo D, Chen L, Sun G. Hepatitis B virus-regulated growth of liver cancer cells occurs through the microRNA-340-5p-activating transcription factor 7-heat shock protein A member 1B axis. Cancer Sci 2019; 110:1633-1643. [PMID: 30891870 PMCID: PMC6501011 DOI: 10.1111/cas.14004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 03/12/2019] [Accepted: 03/14/2019] [Indexed: 12/16/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is a common cancer with poor prognosis. Hepatitis B virus (HBV) is one of the leading causes of HCC, but the precise mechanisms by which this infection promotes cancer development are not fully understood. Recently, miR‐340‐5p, a microRNA (miRNA) that has been identified as a cancer suppressor gene, was found to inhibit the migration and invasion of liver cancer cells. However, the effect of miR‐340‐5p on cell proliferation and apoptosis in HBV‐associated HCC remains unknown. In our study, we show that miR‐340‐5p plays an important role during HBV infection and hepatocellular carcinoma development. Specifically, this miRNA directly binds to the mRNA encoding activating transcription factor 7 (ATF7), a protein that both promotes cell proliferation and suppresses apoptosis through its interaction with heat shock protein A member 1B (HSPA1B). We further found that miR‐340‐5p is downregulated by HBV, which enhances ATF7 expression, leading to enhanced cell proliferation and inhibition of apoptosis. Notably, ATF7 is upregulated in HCC tissue, suggesting that HBV may target miR‐340‐5p in vivo to promote ATF7/HSPA1B‐mediated proliferation and apoptosis and regulate liver cancer progression. This work helps to elucidate the complex interactions between HBV and host miRNAs and further suggests that miR‐340‐5p may represent a promising candidate for the development of improved therapeutic strategies for HCC.
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Affiliation(s)
- Feifei Song
- School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Mingcong Wei
- School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Jingwen Wang
- School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Yang Liu
- School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Mingxiong Guo
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xiaolu Li
- Department of Radiation Oncology, Hubei Cancer Hospital, Wuhan, China
| | - Jun Luo
- Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Junying Zhou
- Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Min Wang
- School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Deyin Guo
- School of Medicine, Sun Yat-sen University, Guangdong, China
| | - Lang Chen
- School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Guihong Sun
- School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Allergy and Immunology, Wuhan, China
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5
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Dodurga Y, Seçme M, Lale Şatıroğlu-Tufan N. A novel oncogene URG4/URGCP and its role in cancer. Gene 2018; 668:12-17. [DOI: 10.1016/j.gene.2018.05.047] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 05/13/2018] [Indexed: 01/17/2023]
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6
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Li C, Lin C, Cong X, Jiang Y. PDK1-WNK1 signaling is affected by HBx and involved in the viability and metastasis of hepatic cells. Oncol Lett 2018; 15:5940-5946. [PMID: 29563998 DOI: 10.3892/ol.2018.8001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Accepted: 12/22/2017] [Indexed: 01/04/2023] Open
Abstract
Hepatitis B virus (HBV)-encoded X antigen (HBx) contributes to the development of hepatocellular carcinoma (HCC). Although HBx has been implicated in the progression of HCC, its precise function in HBV-associated HCC remains unclear. In the present study, HBx affected 3-phosphoinositide-dependent protein kinase-1 (PDK1) and with-no-lysine (K) kinase (WNK1) signaling, which was identified to be involved in the viability and metastasis of hepatic cells. The phosphorylation of WNK1 was decreased when the hepatic cells were treated with a PDK1 inhibitor. The inhibition of PDK1 activity inhibited the viability and migration of hepatic cells. To the best of our knowledge, the present study is the first to identify the activation of PDK1 in HCC tissues, confirmed using western blot analysis. PDK1-WNK1 signaling may be a potential therapeutic target in HBV-associated liver cancer.
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Affiliation(s)
- Chaoying Li
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Beijing Institute of Lifeomics, Beijing 102206, P.R. China
| | - Cong Lin
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Beijing Institute of Lifeomics, Beijing 102206, P.R. China
| | - Xianling Cong
- Biobank, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130031, P.R. China
| | - Ying Jiang
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Beijing Institute of Lifeomics, Beijing 102206, P.R. China
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7
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Liu Z, Dai X, Wang T, Zhang C, Zhang W, Zhang W, Zhang Q, Wu K, Liu F, Liu Y, Wu J. Hepatitis B virus PreS1 facilitates hepatocellular carcinoma development by promoting appearance and self-renewal of liver cancer stem cells. Cancer Lett 2017; 400:149-160. [PMID: 28455240 DOI: 10.1016/j.canlet.2017.04.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 03/09/2017] [Accepted: 04/13/2017] [Indexed: 12/12/2022]
Abstract
Hepatitis B virus (HBV) is a major etiologic agent of hepatocellular carcinoma (HCC). However, the molecular mechanism by which HBV infection contributes to HCC development is not fully understood. Here, we initially showed that HBV stimulates the production of cancer stem cells (CSCs)-related markers (CD133, CD117 and CD90) and CSCs-related genes (Klf4, Sox2, Nanog, c-Myc and Oct4) and facilitates the self-renewal of CSCs in human hepatoma cells. Cellular and clinical studies revealed that HBV facilitates hepatoma cell growth and migration, enhances white blood cell (WBC) production in the sera of patients, stimulates CD133 and CD117 expression in HCC tissues, and promotes the CSCs generation of human hepatoma cells and clinical cancer tissues. Detailed studies revealed that PreS1 protein of HBV is required for HBV-mediated CSCs generation. PreS1 activates CD133, CD117 and CD90 expression in normal hepatocyte derived cell line (L02) and human hepatoma cell line (HepG2 and Huh-7); facilitates L02 cells migration, growth and sphere formation; and finally enhances the abilities of L02 cells and HepG2 cells to induce tumorigeneses in nude mice. Thus, PreS1 acts as a new oncoprotein to play a key role in the appearance and self-renewal of CSCs during HCC development.
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Affiliation(s)
- Zhixin Liu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xuechen Dai
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Tianci Wang
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Chengcheng Zhang
- Department of Pathogen Biology and Immunology, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Wenjun Zhang
- Department of Pathogen Biology and Immunology, Guangdong Pharmaceutical University, Guangzhou 510006, China
| | - Wei Zhang
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Qi Zhang
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Kailang Wu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Fang Liu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China.
| | - Yingle Liu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China.
| | - Jianguo Wu
- State Key Laboratory of Virology and College of Life Sciences, Wuhan University, Wuhan 430072, China.
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8
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Bagga S, Rawat S, Ajenjo M, Bouchard MJ. Hepatitis B virus (HBV) X protein-mediated regulation of hepatocyte metabolic pathways affects viral replication. Virology 2016; 498:9-22. [DOI: 10.1016/j.virol.2016.08.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 07/20/2016] [Accepted: 08/06/2016] [Indexed: 12/25/2022]
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9
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Hepatitis C virus drives the pathogenesis of hepatocellular carcinoma: from immune evasion to carcinogenesis. Clin Transl Immunology 2016; 5:e101. [PMID: 27867514 PMCID: PMC5099426 DOI: 10.1038/cti.2016.55] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 08/23/2016] [Accepted: 08/23/2016] [Indexed: 02/08/2023] Open
Abstract
Persistent hepatitis C virus (HCV) infection is associated with high incidence of hepatocellular carcinoma (HCC), the most common primary malignancy of the liver with over half a million new cases diagnosed annually worldwide. The aryl hydrocarbon receptor (AhR) is a ubiquitously expressed transcription factor and its activation by environmental chemicals and by its endogenous ligand kynurenine (Kyn) has been implicated in a variety of tumour-promoting processes such as transformation, tumorigenesis and in immunosuppression that enables tumour survival and growth. Kyn is generated constitutively by human tumour cells via tryptophan (Trp)-2,3-dioxygenase (TDO), a Trp-degrading enzyme expressed in liver, brain and cancer cells. Notably, it has been shown that TDO-derived Kyn suppresses anti-tumour immune responses, thus promoting tumour-cell survival through activation of the AhR pathway. In the context of HCV infection-associated HCC, it was shown that AhR signalling is increased in HCV-infected hepatocytes, and that modifications in the expression of AhR pathway-specific genes are associated with the progression of HCV infection into HCC. Based on these observations, we present and discuss here the hypothesis that HCV infection promotes HCC by modulation of the TDO-Kyn-AhR pathway, resulting in tumorigenesis as well as in suppression of both anti-HCV and anti-tumour immune responses.
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Tornesello ML, Buonaguro L, Buonaguro FM. An overview of new biomolecular pathways in pathogen-related cancers. Future Oncol 2016; 11:1625-39. [PMID: 26043216 DOI: 10.2217/fon.15.87] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cancer molecular pathways are combinations of metabolic processes deregulated in neoplastic cells. Besides pathways specific to tissues from which cancers originate, common neoplastic traits are present among most tumors. Hanahan and Weinberg have described the most critical 'hallmarks' shared by many cancer types. In recent years, cancer stem cell specific properties and pathways have also been identified. Other altered pathways are peculiar of cancer type and cancer stage, even in different cancer stem cell types. In pathogen-related tumors, the alteration of inflammatory and immunologic response along with impairment of cell cycle control represents key molecular events of tumor progression. This article summarizes the recent discoveries of new altered pathways in cancer and their importance in cancer diagnosis and tailored therapies.
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11
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Cho MY, Cheong JY, Lim W, Jo S, Lee Y, Wang HJ, Han KH, Cho H. Prognostic significance of catalase expression and its regulatory effects on hepatitis B virus X protein (HBx) in HBV-related advanced hepatocellular carcinomas. Oncotarget 2015; 5:12233-46. [PMID: 25361011 PMCID: PMC4322996 DOI: 10.18632/oncotarget.2625] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 10/23/2014] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B virus X protein (HBx) plays a role in liver cancer development. We previously showed that ROS increased HBx levels and here, we investigated the role of antioxidants in the regulation of HBx expression and their clinical relevance. We found that overexpression of catalase induced a significant loss in HBx levels. The cysteine null mutant of HBx (Cys-) showed a dramatic reduction in its protein stability. In clonogenic proliferation assays, Huh7-X cells produced a significant number of colonies whereas Huh7-Cys- cells failed to generate them. The Cys at position 69 of HBx was crucial to maintain its protein stability and transactivation function in response to ROS. Among 50 HBV-related hepatocellular carcinoma (HCC) specimens, 72% of HCCs showed lower catalase levels than those of surrounding non-tumor tissues. In advanced stage IV, catalase levels in non-tumor tissues were increased whereas those in tumors were further reduced. Accordingly, patients with a high T/N ratio for catalase showed significantly longer survival than those with a low T/N ratio. Together, catalase expression in HCC patients can be clinically useful for prediction of patient survival, and restoration of catalase expression in HCCs could be an important strategy for intervention in HBV-induced liver diseases.
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Affiliation(s)
- Mi-Young Cho
- Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, The Graduate School, Ajou University, Suwon, Korea. Department of Biomedical Sciences, The Graduate School, Ajou University, Suwon, Korea
| | - Jae Youn Cheong
- Department of Gastroenterology, Ajou University Hospital, Ajou University School of Medicine, Suwon, Korea
| | - Wonchung Lim
- Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, The Graduate School, Ajou University, Suwon, Korea. Current address: Department of Sports Medicine, Cheongju University, Cheongju, Korea
| | - Sujin Jo
- Genomic Instability Research Center, Ajou University School of Medicine, Suwon, Korea
| | - Youngsoo Lee
- Genomic Instability Research Center, Ajou University School of Medicine, Suwon, Korea
| | - Hee-Jung Wang
- Department of Surgery, Ajou University Hospital, Ajou University School of Medicine, Suwon, Korea
| | - Kyou-Hoon Han
- Biomedical Translational Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
| | - Hyeseong Cho
- Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, The Graduate School, Ajou University, Suwon, Korea. Department of Biomedical Sciences, The Graduate School, Ajou University, Suwon, Korea. Genomic Instability Research Center, Ajou University School of Medicine, Suwon, Korea
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12
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Ringelhan M, O'Connor T, Protzer U, Heikenwalder M. The direct and indirect roles of HBV in liver cancer: prospective markers for HCC screening and potential therapeutic targets. J Pathol 2015; 235:355-67. [PMID: 25196558 DOI: 10.1002/path.4434] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 09/01/2014] [Accepted: 09/02/2014] [Indexed: 02/06/2023]
Abstract
Chronic hepatitis B virus (HBV) infection remains the number one risk factor for hepatocellular carcinoma (HCC), accounting for more than 600 000 deaths/year. Despite highly effective antiviral treatment options, chronic hepatitis B (CHB), subsequent end-stage liver disease and HCC development remain a major challenge worldwide. In CHB, liver damage is mainly caused by the influx of immune cells and destruction of infected hepatocytes, causing necro-inflammation. Treatment with nucleoside/nucleotide analogues can effectively suppress HBV replication in patients with CHB and thus decrease the risk for HCC development. Nevertheless, the risk of HCC in treated patients showing sufficient suppression of HBV DNA replication is significantly higher than in patients with inactive CHB, regardless of the presence of baseline liver cirrhosis, suggesting direct, long-lasting, predisposing effects of HBV. Direct oncogenic effects of HBV include integration in the host genome, leading to deletions, cis/trans-activation, translocations, the production of fusion transcripts and generalized genomic instability, as well as pleiotropic effects of viral transcripts (HBsAg and HBx). Analysis of these viral factors in active surveillance may allow early identification of high-risk patients, and their integration into a molecular classification of HCC subtypes might help in the development of novel therapeutic approaches.
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Affiliation(s)
- Marc Ringelhan
- Institute of Virology, Technische Universität München/Helmholtz Zentrum München, Munich, Germany; Second Medical Department, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany; German Centre for Infection research (DZIF), Munich Partner Site, Germany
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13
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Mesri EA, Feitelson MA, Munger K. Human viral oncogenesis: a cancer hallmarks analysis. Cell Host Microbe 2014; 15:266-82. [PMID: 24629334 DOI: 10.1016/j.chom.2014.02.011] [Citation(s) in RCA: 434] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Approximately 12% of all human cancers are caused by oncoviruses. Human viral oncogenesis is complex, and only a small percentage of the infected individuals develop cancer, often many years to decades after the initial infection. This reflects the multistep nature of viral oncogenesis, host genetic variability, and the fact that viruses contribute to only a portion of the oncogenic events. In this review, the Hallmarks of Cancer framework of Hanahan and Weinberg (2000 and 2011) is used to dissect the viral, host, and environmental cofactors that contribute to the biology of multistep oncogenesis mediated by established human oncoviruses. The viruses discussed include Epstein-Barr virus (EBV), high-risk human papillomaviruses (HPVs), hepatitis B and C viruses (HBV and HCV, respectively), human T cell lymphotropic virus-1 (HTLV-1), and Kaposi's sarcoma herpesvirus (KSHV).
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Affiliation(s)
- Enrique A Mesri
- Viral Oncology Program, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA; AIDS Malignancies Scientific Working Group, Miami Center for AIDS Research, Department and Graduate Program in Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Mark A Feitelson
- Department of Biology, Temple University, Philadelphia, PA 19122, USA.
| | - Karl Munger
- Division of Infectious Diseases, Department of Medicine, Brigham and Women Hospital and Harvard Medical School, Boston, MA 02115, USA.
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14
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The hepatitis B virus (HBV) HBx protein activates AKT to simultaneously regulate HBV replication and hepatocyte survival. J Virol 2014; 89:999-1012. [PMID: 25355887 DOI: 10.1128/jvi.02440-14] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
UNLABELLED Chronic infection with hepatitis B virus (HBV) is a risk factor for developing liver diseases such as hepatocellular carcinoma (HCC). HBx is a multifunctional protein encoded by the HBV genome; HBx stimulates HBV replication and is thought to play an important role in the development of HBV-associated HCC. HBx can activate the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway in some cell lines; however, whether HBx regulates PI3K/AKT signaling in normal hepatocytes has not been evaluated. In studies described here, we assessed HBx activation of PI3K/AKT signaling in an ex vivo model of cultured primary hepatocytes and determined how this HBx activity affects HBV replication. We report that HBx activates AKT in primary hepatocytes and that the activation of AKT decreases HBV replication and HBV mRNA and core protein levels. We show that the transcription factor hepatocyte nuclear factor 4α (HNF4α) is a target of HBx-regulated AKT, and we link HNF4α to HBx-regulated AKT modulation of HBV transcription and replication. Although we and others have shown that HBx stimulates and is likely required for HBV replication, we now report that HBx also activates signals that can diminish the overall level of HBV replication. While this may seem counterintuitive, we show that an important effect of HBx activation of AKT is inhibition of apoptosis. Consequently, our studies suggest that HBx balances HBV replication and cell survival by stimulating signaling pathways that enhance hepatocyte survival at the expense of higher levels of HBV replication. IMPORTANCE Chronic hepatitis B virus (HBV) infection is a common cause of the development of liver cancer. Regulation of cell signaling pathways by the HBV HBx protein is thought to influence the development of HBV-associated liver cancer. HBx stimulates, and may be essential for, HBV replication. We show that HBx activates AKT in hepatocytes to reduce HBV replication. While this seems contradictory to an essential role of HBx during HBV replication, HBx activation of AKT inhibits hepatocyte apoptosis, and this may facilitate persistent, noncytopathic HBV replication. AKT regulates HBV replication by reducing the activity of the transcription factor hepatocyte nuclear factor 4α (HNF4α). HBx activation of AKT may contribute to the development of liver cancer by facilitating persistent HBV replication, augmenting the dedifferentiation of hepatocytes by inhibiting HNF4α functions, and activating AKT-regulated oncogenic pathways. AKT-regulated factors may provide therapeutic targets for inhibiting HBV replication and the development of HBV-associated liver cancer.
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15
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Suhail M, Abdel-Hafiz H, Ali A, Fatima K, Damanhouri GA, Azhar E, Chaudhary AGA, Qadri I. Potential mechanisms of hepatitis B virus induced liver injury. World J Gastroenterol 2014; 20:12462-12472. [PMID: 25253946 PMCID: PMC4168079 DOI: 10.3748/wjg.v20.i35.12462] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [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] [Accepted: 05/19/2014] [Indexed: 02/06/2023] Open
Abstract
Chronic active hepatitis (CAH) is acknowledged as an imperative risk factor for the development of liver injury and hepatocellular carcinoma. The histological end points of CAH are chronic inflammation, fibrosis and cirrhosis which are coupled with increased DNA synthesis in cirrhotic vs healthy normal livers. The potential mechanism involved in CAH includes a combination of processes leading to liver cell necrosis, inflammation and cytokine production and liver scaring (fibrosis). The severity of liver damage is regulated by Hepatitis B virus genotypes and viral components. The viral and cellular factors that contribute to liver injury are discussed in this article. Liver injury caused by the viral infection affects many cellular processes such as cell signaling, apoptosis, transcription, DNA repair which in turn induce radical effects on cell survival, growth, transformation and maintenance. The consequence of such perturbations is resulted in the alteration of bile secretion, gluconeogenesis, glycolysis, detoxification and metabolism of carbohydrates, proteins, fat and balance of nutrients. The identification and elucidation of the molecular pathways perturbed by the viral proteins are important in order to design effective strategy to minimize and/or restore the hepatocytes injury.
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Abstract
Chronic hepatitis B (CHB) infection is a major cause of human mortality worldwide. The majority of people with CHB are infected early in life, and 20-40% of men and 15% of women with chronic infection will develop hepatocellular carcinoma (HCC). Antiviral therapy is recommended for patients with CHB who have cirrhosis or active disease with the aims of reducing disease progression to cirrhosis, liver failure and liver cancer, thereby preventing death. Evidence that treatment with interferon or with early nucleos(t)ide analogue therapy reduces HCC has been somewhat conflicting, however evidence is emerging to support a significant role in HCC prevention of the more effective antivirals, entecavir and tenofovir. Older patients, those with cirrhosis, and those undergoing curative treatments for HCC derive the greatest medium-term benefit in terms of HCC reduction, but HCC can still occur and long-term surveillance is recommended.
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Affiliation(s)
- Simone I Strasser
- Royal Prince Alfred Hospital - AW Morrow Gastroenterology and Liver Centre, Missenden Rd, Camperdown, New South Wales 2050, Australia
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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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Lou X, Hou Y, Liang D. Effects of hepatitis B virus X protein on human T cell cytokines. Can J Microbiol 2013; 59:620-6. [PMID: 24011345 DOI: 10.1139/cjm-2013-0259] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Chronic infection with hepatitis B virus (HBV) plays a significant role in hepatocellular carcinoma development. To investigate the effect of hepatitis B virus X protein (HBx) on inflammatory cytokines of human T cell, a eukaryotic expression vector, HBx-pEGFP-C1, was constructed and transfected into the Jurkat human T-cell line. Jurkat cells were transfected transiently using Lipofectamine 2000 and activated by phytohemagglutinin (PHA). Interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), IL-4, IL-10, IL-13, and IL-14 mRNA was measured. The results showed that the vector HBx-pEGFP-C1 was successfully constructed, and HBx was expressed in Jurkat cells. Compared with a control group, mRNA of IL-1β and TNF-α was significantly elevated in the HBx-pEGFP-C1 group (p < 0.05), while IL-4, IL-10, IL-13, and IL-14 mRNA was decreased (p < 0.05). Therefore, transient overexpression of HBx promoted PHA-induced pro-inflammatory cytokine secretion and repressed anti-inflammatory cytokine secretion in human T cells.
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Affiliation(s)
- XiaoLi Lou
- Department of Central Laboratory, Songjiang Hospital Affiliated First People's Hospital, Shanghai Jiao Tong University, Shanghai 201600, People's Republic of China
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Arzumanyan A, Reis HMGPV, Feitelson MA. Pathogenic mechanisms in HBV- and HCV-associated hepatocellular carcinoma. Nat Rev Cancer 2013; 13:123-35. [PMID: 23344543 DOI: 10.1038/nrc3449] [Citation(s) in RCA: 599] [Impact Index Per Article: 54.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hepatocellular carcinoma (HCC) is a highly lethal cancer, with increasing worldwide incidence, that is mainly associated with chronic hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infections. There are few effective treatments partly because the cell- and molecular-based mechanisms that contribute to the pathogenesis of this tumour type are poorly understood. This Review outlines pathogenic mechanisms that seem to be common to both viruses and which suggest innovative approaches to the prevention and treatment of HCC.
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Affiliation(s)
- Alla Arzumanyan
- Department of Biology and Sbarro Health Research Organization, College of Science and Technology, Temple University, 1900 N. 12th Street, Philadelphia, Pennsylvania 19122, USA
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Tang RX, Kong FY, Fan BF, Liu XM, You HJ, Zhang P, Zheng KY. HBx activates FasL and mediates HepG2 cell apoptosis through MLK3-MKK7-JNKs signal module. World J Gastroenterol 2012; 18:1485-95. [PMID: 22509080 PMCID: PMC3319944 DOI: 10.3748/wjg.v18.i13.1485] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Revised: 10/02/2011] [Accepted: 01/18/2012] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the possible mechanism by which hepatitis B virus X protein (HBx) mediates apoptosis of HepG2 cells. METHODS HBx expression vector pcDNA3.1-X was transfected into HepG2 cells to establish an HBx high-expression cellular model as pcDNA3.1-X transfected group. The pcDNA3.1-X and pSilencer3.1-shHBX (HBx antagonist) were cotransfected into HepG2 cells to establish an HBx low-expression model as RNAi group. Untransfected HepG2 cells and HepG2 cells transfected with negative control plasmid were used as controls. Apoptosis rate, the expression of Fas/FasL signaling pathway-related proteins and the phosphorylation levels of MLK3, MKK7 and JNKs, which are upstream molecules of death receptor pathways and belong to the family of mitogen-activated protein kinases (MAPKs), were measured in each group. RESULTS Compared with HepG2 cell group and RNAi group, apoptosis rate, the expression of Fas and FasL proteins, and the activation of MLK3, MKK7 and JNKs were increased in the pcDNA3.1-X transfected group. The activation of JNKs and expression of FasL protein were inhibited in the pcDNA3.1-X transfected group when treated with a known JNK inhibitor, SP600125. When authors treated pcDNA3.1-X transfected group with K252a, a known MLK3 inhibitor, the activation of MLK3, MKK7 and JNKs as well as expression of FasL protein was inhibited. Furthermore, cell apoptosis rate was also significantly declined in the presence of K252a in the pcDNA3.1-X transfected group. CONCLUSION HBx can induce HepG2 cell apoptosis via a novel active MLK3-MKK7-JNKs signaling module to upregulate FasL protein expression.
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Liao HH, Nawarak J, Chang KL, Hsieh WY, Tsai HY, Chen ST, Cheng SL. Screening and Identification of Peptides that Bind Specifically to the X gene Promoter of Hepatitis B Virus Using a Combinatorial Peptide Library Approach. J CHIN CHEM SOC-TAIP 2011. [DOI: 10.1002/jccs.201190138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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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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Guo C, Li D, Lin N, Huang YH, Chen ZX, Wang XZ. Establishment of a mouse model harboring the hepatitis B virus X gene and analysis of expression of apoptosis factors in liver cells of this mouse line. Shijie Huaren Xiaohua Zazhi 2011; 19:1225-1230. [DOI: 10.11569/wcjd.v19.i12.1225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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
AIM: To investigate the impact of the hepatitis B virus X gene (HBVX) on the expression of apoptosis factors in liver cells.
METHODS: The eukaryotic expression vector PCDNA3.1-HBVX was injected into the caudal vein of mice to establish a mouse model expressing the HBVX gene. Mice injected with empty PCDNA3.1 vector or normal saline were used as controls. RT-PCR and Western blot were performed to detect the expression of HBVX in liver tissue 48 h after injection. Semi-quantitative RT-PCR was used to evaluate the expression of bax, bcl-2, and c-myc in liver cells of different groups of mice.
RESULTS: HBX mRNA and protein were detected in liver tissue in mice injected with the PCDNA3.1-HBVX vector, but not in controls. Compared to controls, the expression of bax, c-myc and bcl-2 was up-regulated in liver tissue in mice injected with the PCDNA3.1-HBVX vector (bax: 1.3127 ± 0.0900 vs 1.0023 ± 0.1670, 0.9094 ± 0.1081; c-myc: 1.6294 ± 0.0672 vs 1.2869 ± 0.0880, 0.9757 ± 0.0397; bcl-2: 1.5567 ± 0.1257 vs 0.6856 ± 0.1554, 0.5488 ± 0.1278, all P < 0.05).
CONCLUSION: A mouse model harboring the HBVX gene has been established successfully. Expression of the HBx gene can up-regulate the expression of Bax, c-Myc and Bcl-2 in liver cells.
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Fan R, Li X, Du W, Zou X, Du R, Zhao L, Luo G, Mo P, Xia L, Pan Y, Shi Y, Lian Z, Feitelson MA, Nie Y, Liu J, Fan D. Adenoviral-mediated RNA interference targeting URG11 inhibits growth of human hepatocellular carcinoma. Int J Cancer 2010; 128:2980-93. [PMID: 20725996 DOI: 10.1002/ijc.25624] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Accepted: 07/30/2010] [Indexed: 01/25/2023]
Abstract
Hepatocellular carcinoma (HCC) is the second most common malignancy in Asia, with a 5-year survival rate of less than 5% due to high recurrence after surgery and resistance to chemotherapy. A variety of therapeutic interventions to treat HCC, particularly gene therapy, have recently been investigated in tumor model systems to provide a more complete understanding of hepatocarcinogenesis and effectively design therapeutic strategies to treat this disease. In our study, we constructed an adenoviral vector expressing small interfering RNA (siRNA) targeting a newly discovered gene named upregulated gene 11 (URG11). We introduced this vector into HCC cells to investigate the role of URG11 in HCC carcinogenesis. We observed that upon URG11 knockdown, HCC cell proliferation was inhibited through downregulation of several G1-S phase related molecules including cyclin D1 and apoptosis was induced as a result of Bcl-2 downregulation. Besides decreased expression of cyclin D1, CDK4, pRb and Bcl-2, URG11 also suppressed several other proteins including CAPN9, which was identified by cDNA microarray and 2D gel electrophoresis. Moreover, Ad-URG11-siRNA significantly suppressed HCC tumor growth in nude mice. In conclusion, Ad-URG11-siRNA can significantly suppress HCC tumor growth in vitro and in vivo by silencing the URG11 gene, and the use of this vector for gene therapy may represent a novel strategy to treat human HCC.
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Affiliation(s)
- Rui Fan
- State Key Laboratory of Cancer Biology, Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, Xi'an, Shaanxi Province, People's Republic of China
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25
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Guan ZJ, Guo B, Huo YL, Guan ZP, Wei YH. Overview of expression of hepatitis B surface antigen in transgenic plants. Vaccine 2010; 28:7351-62. [PMID: 20850538 DOI: 10.1016/j.vaccine.2010.08.100] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2010] [Revised: 08/20/2010] [Accepted: 08/31/2010] [Indexed: 11/18/2022]
Abstract
Hepatitis B virus (HBV), a pathogen for chronic liver infection, afflicts more than 350 million people world-wide. The effective way to control the virus is to take HBV vaccine. Hepatitis B surface antigen (HBsAg) is an effective protective antigen suitable for vaccine development. At present, "edible" vaccine based on transgenic plants is one of the most promising directions in novel types of vaccines. HBsAg production from transgenic plants has been carried out, and the transgenic plant expression systems have developed from model plants (such as tobacco, potato and tomato) to other various plant platforms. Crude or purified extracts of transformed plants have been found to conduct immunological responses and clinical trials for hepatitis B, which gave the researches of plant-based HBsAg production a big boost. The aim of this review was to summarize the recent data about plant-based HBsAg development including molecular biology of HBsAg gene, selection of expression vector, the expression of HBsAg gene in plants, as well as corresponding immunological responses in animal models or human.
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Affiliation(s)
- Zheng-jun Guan
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education Northwest University, Xi'an 710069, China.
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HBx-Induced Hepatic Steatosis and Apoptosis Are Regulated by TNFR1- and NF-κB-Dependent Pathways. J Mol Biol 2010; 397:917-31. [DOI: 10.1016/j.jmb.2010.02.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 02/05/2010] [Accepted: 02/09/2010] [Indexed: 12/15/2022]
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Holotnakova T, Tylkova L, Takacova M, Kopacek J, Petrik J, Pastorekova S, Pastorek J. Role of the HBx oncoprotein in carbonic anhydrase 9 induction. J Med Virol 2010; 82:32-40. [PMID: 19950233 DOI: 10.1002/jmv.21671] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Carbonic anhydrase 9 (CA9), as one of the most hypoxia-responsive genes, has been associated almost exclusively with hypoxic tumors. Its principal role is in pH regulation which helps tumor cells overcome intracellular acidosis and survive extended periods of time with low oxygen. Hypoxia-inducible factor 1 (HIF-1) is the main transcriptional activator of CA9. Hepatitis B virus X protein (HBx) has been shown to increase the transcriptional activity of HIF-1. HBx is often expressed from the gene integrated in the hepatocytes infected persistently and contributes significantly to alterations in host gene expression that can lead to the development of hepatocellular carcinoma (HCC) associated with Hepatitis B virus (HBV). The aim of this study was to determine the effect of HBx on expression of CA9. Transient transfection of HBx led to an increase in the expression of CA9 as assessed by RT-PCR and Western blotting. HBx was able to increase CA9 promoter activity significantly in several cell lines. The effect was mediated via HIF-1 and a functional HRE element located -10/-3 bp upstream of the CA9 transcription initiation site. These data suggest that CA9 may be involved in the development of HCC by contributing to the survival of hepatocytes infected with HBV in liver tissue with fibrosis.
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Affiliation(s)
- Tereza Holotnakova
- Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovak Republic
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28
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Feitelson MA, Arzumanyan A. Mitochondria-associated HBV x antigen: what is going on? Future Virol 2009. [DOI: 10.2217/17460794.4.2.127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Evaluation of: Clippinger AJ, Bouchard MJ: Hepatitis B virus HBx protein localizes to mitochondria in primary rat hepatocytes and modulates mitochrondrial membrane potential. J. Virol. 82(14), 6798–6811 (2008). Over 350 million people are chronically infected with HBV, and a significant number of these individuals develop primary liver cancer. HBV encodes seven viral proteins, including the nonstructural Hepatitis B x (HBx) protein. The results of studies with immortalized or transformed cells and with HBx transgenic mice demonstrated that HBx can interact with mitochondria. However, no studies with normal hepatocytes have characterized the precise mitochondrial localization of HBx or the effect of HBx on mitochondrial physiology. We have used cultured primary rat hepatocytes as a model system to characterize the mitochondrial localization of HBx and the effect of HBx expression on mitochondrial physiology. We now show that a fraction of HBx co-localizes with density gradient-purified mitochondria and associates with the outer mitochondrial membrane. We also demonstrate that HBx regulates mitochondrial membrane potential in hepatocytes, and that this function of HBx varies depending upon the status of NF-κB activity. In primary rat hepatocytes, HBx activation of NF-κB prevented mitochondrial membrane depolarization; however, when NF-κB activity was inhibited, HBx induced membrane depolarization through modulation of the mitochondrial permeability transition pore. Collectively, these results define potential pathways through which HBx may act in order to modulate mitochondrial physiology, thereby altering many cellular activities and ultimately contributing to the development of HBV-associated liver cancer.
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Affiliation(s)
- Mark A Feitelson
- Suite 409 BioLife Science Building, Department of Biology, Center for Biotechnology, Temple University, 1900 N 12th Street, Philadelphia, PA 19122, USA
| | - Alla Arzumanyan
- Suite 409 BioLife Science Building, Department of Biology, Center for Biotechnology, Temple University, 1900 N 12th Street, Philadelphia, PA 19122, USA
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Putative roles of hepatitis B x antigen in the pathogenesis of chronic liver disease. Cancer Lett 2009; 286:69-79. [PMID: 19201080 DOI: 10.1016/j.canlet.2008.12.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 11/18/2008] [Accepted: 12/02/2008] [Indexed: 12/18/2022]
Abstract
Under most circumstances, hepatitis B virus (HBV) is noncytopathic. However, hepatocellular regeneration that accompanies each bout of hepatitis appears to be associated with increased integration of HBV DNA fragments expressing the virus encoded hepatitis B x antigen (HBxAg). Intrahepatic HBxAg staining correlates with the intensity and progression of chronic liver disease (CLD), and additional work has shown that HBxAg blocks immune mediated killing by Fas and by tumor necrosis factor alpha (TNFalpha). This is not only associated with the blockage of caspase activities by HBxAg, but also by the constitutive stimulation of hepatoprotective pathways, such as nuclear factor kappa B (NF-kappaB), phosphoinositol 3-kinase (PI3K), and beta-catenin (beta-catenin). HBxAg also appears to promote fibrogenesis, by stimulating the production of fibronectin. HBxAg also stimulates the production and activity of transforming growth factor beta1 (TGFbeta1) by several mechanisms, thereby promoting the profibrogenic and tumorigenic properties of this important cytokine. In addition, HBxAg appears to remodel the extracellular matrix (ECM) by altering the expression of several matrix metalloproteinases (MMPs), which may promote tumor metastasis. Hence, HBxAg appears to promote chronic infection by preventing immune mediated apoptosis of infected hepatocytes, by promoting the establishment and persistence of fibrosis and cirrhosis preceding the development of HCC, and by promoting the remodeling of EMC during tumor progression.
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Feitelson MA, Reis HMGPV, Pan J, Clayton M, Sun B, Satiroglu-Tufan NL, Lian Z. HBV X protein: elucidating a role in oncogenesis. Future Virol 2008. [DOI: 10.2217/17460794.3.5.455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chronic HBV infection is associated with the development of hepatocellular carcinoma (HCC). HBV contributes to tumorigenesis by encoding hepatitis B x antigen (HBxAg), which is a trans-regulatory protein that appears to contribute to HCC by altering patterns of host gene expression. In this review, recent data is presented that outlines some of the putative mechanisms whereby HBxAg contributes to HCC. With the development of animal models of HBxAg-mediated HCC, the relevance and temporal order of putative steps in this process can now be dissected to elucidate what is rate limiting and when. This will have a profound impact on the design of novel and specific therapeutics for HCC.
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Affiliation(s)
- Mark A Feitelson
- Department of Biology, College of Science & Technology, Temple University, PA 19122, USA. and, Center for Biotechnology, College of Science & Technology, Temple University, PA 19122, USA
| | - Helena MGPV Reis
- MIT Portugal Program, Av. Antonio Jose de Almeida, 12 1000–043 Lisboa, Portugal
| | - Jingbo Pan
- Department of Pathology, Anatomy & Cell Biology, Thomas Jefferson University, PA 19107, USA
| | - Marcy Clayton
- Department of Biology, College of Science & Technology, Temple University, PA 19122, USA
| | - Bill Sun
- Department of Biology, College of Science & Technology, Temple University, PA 19122, USA
| | - N Lale Satiroglu-Tufan
- Department of Medical Biology, Pamukkale University School of Medicine, Kinikli Kampusu Morfoloji Binasi, 20020 Denizli, Turkey
| | - Zhaorui Lian
- Department of Biology, College of Science & Technology, Temple University, PA 19122, USA
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Feitelson MA, Clayton MM, Sun B, Schinazi RF. Development of a novel mouse model to evaluate drug candidates against hepatitis B virus. Antivir Chem Chemother 2008; 18:213-23. [PMID: 17907379 PMCID: PMC7656857 DOI: 10.1177/095632020701800405] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Woodchuck hepatitis virus (WHV)-infected woodchucks have been used for preclinical development of drugs against hepatitis B virus (HBV). However, there is no simple in vivo model to evaluate small amounts of compounds against HBV. To develop such a model, HepAD38 cells, in which HBV replication is regulated by tetracycline (tet), were grown as subcutaneous tumours in nude mice. Mice developing viraemia were then left untreated or given tet in the drinking water. In some of the mice given tet, it was removed and the mice were injected intraperitoneally with phosphate buffer saline (PBS), lamivudine (3TC), clevudine (CLV) or tenofovir dipivoxil fumarate (TDF). Virus DNA titres were measured by real-time PCR during and after drug treatment. In water-fed and PBS-injected mice, virus titres reached approximately 10(9) copies/ml serum within 35 days of HepAD38 injection, whereas in tet-treated mice, virus titres remained at 10(4)-10(5) copies/ml. HBV DNA levels were suppressed by 3TC, TDF and CLV, with the latter two drugs showing more sustained virus suppression compared with 3TC. Combination therapy with CLV plus TDF was much more effective than either drug alone in suppressing virus titre for at least 3 weeks after the end of treatment. There was no demonstrable toxicity to HepAD38 cells in drug-treated mice. Hence, a robust tet-controlled system for HBV replication in vivo was demonstrated, validated with monotherapies against HBV and shown to be useful in assessing combination therapy. This system will be useful for preclinical assessment of small amounts of single or multiple compounds against HBV in vivo.
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Affiliation(s)
- Mark A Feitelson
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA.
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The hepatitis B x antigen effector, URG7, blocks tumour necrosis factor α-mediated apoptosis by activation of phosphoinositol 3-kinase and β-catenin. J Gen Virol 2007; 88:3275-3285. [DOI: 10.1099/vir.0.83214-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Hepatitis B x antigen (HBxAg) contributes significantly to the pathogenesis of chronic infection and development of hepatocellular carcinoma. To discern some of its operative pathways, HepG2 cells were stably transduced with HBx or the bacterial chloramphenicol acetyltransferase (CAT) gene. Differential gene expression has previously revealed an upregulated gene, clone 7 (URG7), that conferred resistance to anti-Fas killing on HepG2X cells. Given that tumour necrosis factor alpha (TNFα) is also an important mediator of chronic hepatitis, and partially shares signalling with Fas, experiments were designed to test whether URG7 blocks TNFα killing of HepG2X cells. HepG2X cells expressing URG7 and HepG2 cells overexpressing URG7 in the absence of HBxAg were resistant to TNFα killing compared with HepG2CAT cells. URG7 small interfering RNA restored the sensitivity of HepG2X cells to TNFα killing. Killing was associated with the activation of caspases 3 and 8, suggesting that URG7 blocked these caspases. This resistance was also associated with activation of phosphoinositol 3-kinase/Akt. Given that Akt and HBxAg also activate β-catenin, experiments were designed to determine whether URG7 blocked apoptosis via activation of β-catenin. Both HBxAg and URG7 activated fragments of the β-catenin promoter, and also promoted expression of β-catenin target genes. Hence, URG7 inhibits TNFα-mediated killing by blocking one or more caspases in the apoptotic pathway and by activating phosphoinositol 3-kinase and β-catenin, thereby overriding the apoptotic signalling of TNFα. This suggests that URG7 helps to protect virus-infected hepatocytes during chronic hepatitis B virus infection.
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Lian Z, Liu J, Wu M, Wang HY, Arbuthnot P, Kew M, Feitelson MA. Hepatitis B x antigen up-regulates vascular endothelial growth factor receptor 3 in hepatocarcinogenesis. Hepatology 2007; 45:1390-9. [PMID: 17539024 DOI: 10.1002/hep.21610] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Hepatitis B x antigen (HBxAg) is a trans-activating protein that contributes to liver cancer, in part, by altering the expression of cellular genes. However, few natural effectors of HBxAg have been identified. Hence, HBxAg positive and negative HepG2 cells were prepared and analyzed by PCR select cDNA subtraction. The results identified elevated vascular endothelial growth factor receptor-3 short form splice variant (VEGFR-3(S)) expression in HBxAg positive compared to negative cells. Normally, VEGFR-3 activates Akt signaling in lymphatic endothelial cells, resulting in lymphangiogenesis. In contrast, the results here show that the expression of VEGFR-3(S) is up-regulated in >75% of HBxAg positive hepatocellular carcinoma (HCC) nodules. VEGFR-3(S) up-regulation correlates with the expression of HBxAg, is associated with decreased survival in tumor bearing patients, and when over-expressed in HepG2 cells, strongly stimulated cell growth in culture, in soft agar, and accelerated tumor formation in a ligand independent manner. VEGFR-3(S) siRNA partially blocked the ability of HBxAg to promote hepatocellular growth. In conclusion, HBxAg may short circuit VEGFR-3(S) signaling in liver cancer. Blocking VEGFR-3(S) signaling may be effective in preventing tumor development and/or prolonging survival in tumor bearing patients.
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Affiliation(s)
- Zhaorui Lian
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
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Kim S, Kim HY, Lee S, Kim SW, Sohn S, Kim K, Cho H. Hepatitis B virus x protein induces perinuclear mitochondrial clustering in microtubule- and Dynein-dependent manners. J Virol 2007; 81:1714-26. [PMID: 17151129 PMCID: PMC1797565 DOI: 10.1128/jvi.01863-06] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The hepatitis B virus (HBV) X protein (HBx) is thought to play a key role in HBV replication and the development of liver cancer. It became apparent that HBx induces mitochondrial clustering at the nuclear periphery, but the molecular basis for mitochondrial clustering is not understood. Since mitochondria move along the cytoskeleton as a cargo of motor proteins, we hypothesized that mitochondrial clustering induced by HBx occurs by an altered intracellular motility. Here, we demonstrated that the treatment of HBx-expressing cells with a microtubule-disrupting drug (nocodazole) abrogated mitochondrial clustering, while the removal of nocodazole restored clustering within 30 to 60 min, indicating that mitochondrial transport is occurring in a microtubule-dependent manner. The addition of a cytochalasin D-disrupting actin filament, however, did not measurably affect mitochondrial clustering. Mitochondrial clustering was further studied by observations of HBV-related hepatoma cells and HBV-replicating cells. Importantly, the abrogation of the dynein activity in HBx-expressing cells by microinjection of a neutralizing anti-dynein intermediate-chain antibody, dynamitin overexpression, or the addition of a dynein ATPase inhibitor significantly suppressed the mitochondrial clustering. In addition, HBx induced the activation of the p38 mitogen-activated protein kinase (MAPK) and inhibition of the p38 kinase activity by SB203580-attenuated HBx-induced mitochondrial clustering. Taken together, HBx activation of the p38 MAPK contributed to the increase in the microtubule-dependent dynein activity. The data suggest that HBx plays a novel regulatory role in subcellular transport systems, perhaps facilitating the process of maturation and/or assembly of progeny particles during HBV replication. Furthermore, mitochondrion aggregation induced by HBx may represent a cellular process that underlies disease progression during chronic viral infection.
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Affiliation(s)
- Sujeong Kim
- Department of Biochemistry, Ajou University School of Medicine, 5 Wonchon-dong, Yeongtong-gu, Suwon 443-721, Korea
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Lian Z, Liu J, Li L, Li X, Clayton M, Wu MC, Wang HY, Arbuthnot P, Kew M, Fan D, Feitelson MA. Enhanced cell survival of Hep3B cells by the hepatitis B x antigen effector, URG11, is associated with upregulation of beta-catenin. Hepatology 2006; 43:415-24. [PMID: 16496348 DOI: 10.1002/hep.21053] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Intrahepatic expression of hepatitis B x antigen (HBxAg) is associated with the development of hepatocellular carcinoma (HCC), perhaps through trans-activation of selected cellular genes. When this was examined by PowerBlot analysis, upregulated levels of beta-catenin and several known beta-catenin effectors were observed in HBxAg-positive compared with HBxAg-negative HepG2 cells. When HBxAg was introduced into Hep3B cells, upregulated expression of wild-type beta-catenin was observed. This was also observed in Hep3B cells overexpressing the HBxAg upregulated gene, URG11. Upregulated expression of URG11 and beta-catenin correlated with HBxAg trans-activation function. Transient transfection assays with fragments of the beta-catenin promoter showed that it was activated by both HBxAg and URG11 and inhibited by URG11-specific small inhibitory RNA. The latter also inhibited the growth of Hep3BX cells in a serum-free medium, which correlated with depressed levels of beta-catenin. Activation of beta-catenin effector genes was observed in cells stably expressing HBxAg or overexpressing URG11 compared with control cells transfected with the pTOPFLASH reporter plasmid. Extensive costaining between HBxAg, URG11, and beta-catenin was observed in infected liver and HCC nodules, suggesting a close relationship in vivo. In conclusion, wild-type beta-catenin is activated by HBxAg, in part, through the upregulated expression of the HBxAg effector URG11. URG11 stimulates the beta-catenin promoter and hepatocellular growth and survival. These observations also suggest that URG11 may be a regulatory element in the beta-catenin signaling pathway and may be a target for chemoprevention of HCC.
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Affiliation(s)
- Zhaorui Lian
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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Zhu R, Huang H, Zhang H, Wang Z, Hu X, Zhai W, Lin Y, Wang J, Zhu H. Prognostic analysis in chronic hepatitis B patients: a retrospective study of 216 cases about Scheuer scores, in situ expression of viral antigens and tissue hepatitis B virus DNA levels. Liver Int 2006; 26:82-9. [PMID: 16420513 DOI: 10.1111/j.1478-3231.2005.01199.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND Most of the previous studies of patients with chronic hepatitis B virus (HBV) infection concentrated on serum samples. Liver biopsy specimens for HBV have not been systematically analyzed. This study was performed to analyze some histopathological indicators (Scheuer scores, the expression of HBV antigens in situ, HBV DNA quantification) in the biopsy samples and showed the relationship among them and the prognosis of chronic hepatitis. METHODS A total of 216 consecutive chronic HBV-infected patients were followed up by clinical and laboratory data and classified into two groups at first: carcinogenesis and non-carcinogenesis. The non-carcinogenesis also included two groups: cirrhosis and non-cirrhosis. The non-cirrhosis was still divided into fluctuation and normalization at last. Histological activity index was described by Scheuer scores. Two-step immunohistochemical staining showed the expression of viral antigens in situ. Tissue HBV DNA levels were determined by fluorescence quantitative real-time PCR. RESULTS Regression analysis revealed significant positive correlations between the expression of hepatitis B e antigen (HBeAg) and grading, as well as between hepatitis Bx (HBx) protein and grading or staging of Scheuer scores. Positive correlations between grading or staging and prognosis were statistically significant. The expressions of HBeAg and HBx protein were higher in patients with cirrhosis than those without cirrhosis. Scheuer score was the most important indicator of prognosis. CONCLUSIONS HBeAg and HBx protein can be used as indicators of hepatitis activity and their positive expressions increase the risk for cirrhosis remarkably. In addition to be a marker of liver damage, Scheuer score is the most reliable indicator of the prognosis.
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Affiliation(s)
- Rong Zhu
- Department of Pathology and Pathology Research Center, Shanghai Medical College, Shanghai, China
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Mishiro T, Hamamoto S, Furuta K, Ishimura N, Rumi MAK, Miyake T, Sato S, Ishihara S, Adachi K, Kinoshita Y. Quantitative measurement of hepatitis B virus DNA in different areas of hepatic lobules in patients with chronic hepatitis B. J Med Virol 2005; 78:37-43. [PMID: 16299726 DOI: 10.1002/jmv.20501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Liver histology in chronic hepatitis B is marked by inflammatory infiltration involving the peripheral zones. The cause of such cellular infiltration remains unknown. The aim of the present study was to investigate the amounts of intrahepatic hepatitis B virus (HBV) DNA separately in the peripheral and central zones, using laser capture microdissection coupled with real-time quantitative polymerase chain reaction. Fourteen patients with chronic hepatitis B were included in the study. Liver biopsy samples were taken and hepatocytes were microdissected separately from peripheral and central zones. DNA was extracted from hepatocytes in each zone and evaluated the amounts of HBV-DNA. Immunohistochemical study for hepatitis B core antigen (HBcAg) was also performed. The amounts of total intrahepatic HBV-DNA in patients positive for hepatitis Be antigen (HBeAg) were greater than those in HBeAg-negative patients. There was no difference in HBV-DNA between the peripheral and central zones. Immunohistochemistry also showed that HBcAg-positive cells were distributed homogeneously in the hepatic lobules. In patients with peripherally predominant HBV-DNA, the serum alanine aminotransferase (ALT) level was lower than in patients with centrally predominant HBV-DNA. HBV-DNA was distributed homogeneously in the hepatic lobules. In patients with lower amounts of HBV-DNA in the peripheral zone, the serum ALT level tended to be higher than in other patients.
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Affiliation(s)
- Tomoko Mishiro
- Department of Gastroenterology and Hepatology, Shimane University School of Medicine, Izumo, Japan
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Abstract
AIM: To investigate the effect of hepatitis B virus (HBV) X gene on apoptosis and expressions of apoptosis factors in X gene-transfected HepG2 cells.
METHODS: The HBV X gene eukaryon expression vector pcDNA3-X was transiently transfected into HepG2 cells by lipid-media transfection. Untransfected HepG2 and HepG2 transfected with pcDNA3 were used as controls. Expression of HBx in HepG2 was identified by RT-PCR. MTT and TUNEL were employed to measure proliferation and apoptosis of cells in three groups. Semi-quantified RT-PCR was used to evaluate the expression levels of Fas/FasL, Bax/Bcl-xL, and c-myc in each group.
RESULTS: HBV X gene was transfected into HepG2 cells successfully. RT-PCR showed that HBx was only expressed in HepG2/pcDNA3-X cells, but not expressed in HepG2 and HepG2/pcDNA3 cells. Analyzed by MTT, cell proliferation capacity was obviously lower in HepG2/pcDNA3-X cells (0.08910±0.003164) than in HepG2 (0.14410±0.004927) and HepG2/pcDNA3 cells (0.12150±0.007159) (P<0.05 and P<0.01). Analyzed by TUNEL, cell apoptosis was much more in HepG2/pcDNA3-X cells (980/2 000) than HepG2 (420/2 000), HepG2/pcDNA3 cells (520/2 000) (P<0.05 and P<0.01). Evaluated by semi-quantified RT-PCR, the expression level of Fas/FasL was significantly higher in HepG2 cells transfected with HBx than in HepG2 and HepG2/pcDNA3cells (P<0.05 and P<0.01). Bax/Bcl-xL expression level was also elevated in HepG2/pcDNA3-X cells (P<0.05 and P<0.01). Expression of c-myc was markedly higher in HepG2/pcDNA3-X cells than in HepG2 and HepG2/pcDNA3 cells (P<0.05 andP<0.01).
CONCLUSION: HBV X gene can impair cell proliferation capacity, improve cell apoptosis, and upregulate expression of apoptosis factors. The intervention of HBV X gene on the expression of apoptosis factors may be a possible mechanism responsible for the change in cell apoptosis and proliferation.
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Affiliation(s)
- Na Lin
- Department of Gastroenterology, Affiliated Union Hospital, Fujian Medical University, Fuzhou 350001, Fujian Province, China
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Ge JH, Zhang LZ, Li JX, Liu H, Liu HM, He J, Yao YC, Yang YJ, Yu HY, Hu YP. Replication and gene expression of mutant hepatitis B virus in a transgenic mouse containing the complete viral genome with mutant s gene. World J Gastroenterol 2004; 10:3141-5. [PMID: 15457560 PMCID: PMC4611258 DOI: 10.3748/wjg.v10.i21.3141] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIM: To establish the transgenic mouse line harbouring complete hepatitis B virus (HBV) genome with mutant s gene (adr subtype).
METHODS: Transgenic mice were generated by microinjecting HBV genome into fertilized eggs. Integration, expression, replication of HBV gene and histological changes in transgenic mice were estimated by genomic DNA PCR, serum DNA PCR, Southern blot, ELISA, HE staining, immunohistochemistry and transmission electron microscopy. Transgenic mice with HBsAg positive in serum were bred and analyzed.
RESULTS: A total of 288 eggs survived from microinjections were transplanted into the oviducts of 13 pseudopregnant mice and 49 pups were produced. Twenty-six mice were identified to have the integrated HBV gene. Serum HBsAg and HBeAg were detected in 2 of 43 mice. HBsAg and HBcAg in cytoplasm or nuclei of hepatocytes were detected in 10 mice. Founders with HBsAg in serum were named lineages G145R-15 and G145R-18. Of the 16 F1 offsprings generated by G145R-15 founder, 12 were positive for HBV genome with PCR, 10 were positive for HBsAg and HBcAg with immunohistochemistry and 7 were positive for HBsAg and HBeAg with ELISA. Only 1 of 8 F1 offsprings generated by G145R-18 founder was survived and it was detected positive for HBV genome, HBsAg, HBcAg and HBeAg. Both of the two lineages had some pathological characteristics of mild chronic hepatitis B in the liver, such as swelling of hepatocytes and focal hepatocellular necrosis and parenchymal lymphomononuclear cell infiltrate.
CONCLUSION: Transgenic mice harbouring HBV with mutant s gene can be generated. The HBV genes are integrated in the transgenic mice genome and can be expressed, replicated, packaged and excreted. HBV DNA can be stably transmitted in the transgenic mice.
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Affiliation(s)
- Jun-Hui Ge
- Department of Pathology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, China. gerllini@ yahoo.com.cn
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Hann HWL, Lee J, Bussard A, Liu C, Jin YR, Guha K, Clayton MM, Ardlie K, Pellini MJ, Feitelson MA. Preneoplastic Markers of Hepatitis B Virus-Associated Hepatocellular Carcinoma. Cancer Res 2004; 64:7329-35. [PMID: 15492253 DOI: 10.1158/0008-5472.can-04-1095] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hepatitis B virus (HBV) carriers are at high risk for the development of hepatocellular carcinoma (HCC), but there are no reliable markers that will identify such high-risk carriers. The objective of this work is to identify serologic markers that may indicate the early presence of HCC. Since HBV-encoded X antigen (HBxAg) likely contributes to HCC by up- or down-regulation of host gene expression, X positive and negative HepG2 cells were made and subjected to cDNA subtraction. When specific ELISAs were constructed measuring differentially expressed antigens and corresponding antibodies, antibodies to several differentially expressed genes were detected. In cross-sectional and longitudinal studies, antibodies were predominantly present in patients with HBV-associated cirrhosis and HCC, but not in most carriers with hepatic inflammation alone or without active liver disease. Antibodies were also present in patients with hepatitis C virus (HCV)-related HCC, but rarely detected in sera from uninfected individuals, those with tumors other than HCC, or those with drug-induced hepatitis. Statistical analysis showed that HCC patients with four or more antibodies detectable before the appearance of HCC had decreased survival, suggesting that these markers may reflect stepwise hepatocarcinogenesis. Hence, these antibodies may serve as preneoplastic markers for HCC in HBV carriers with chronic liver disease, and may be identified by a simple blood test.
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Affiliation(s)
- Hie-Won L Hann
- Department of Medicine, Division of Gastroenterology and Hepatology, Jefferson Medical College, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, USA
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Norton PA, Reis HMGPV, Prince S, Larkin J, Pan J, Liu J, Gong Q, Zhu M, Feitelson MA. Activation of fibronectin gene expression by hepatitis B virus x antigen. J Viral Hepat 2004; 11:332-41. [PMID: 15230856 DOI: 10.1111/j.1365-2893.2004.00555.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
The development of fibrosis and cirrhosis during chronic hepatitis B virus (HBV) infection correlates with the persistent expression of HBV x antigen (HBxAg), which acts in part, by stimulating selected signal transduction pathways, including nuclear factor kappa B (NF-kappa B). To identify NF-kappa B responsive genes that are differentially expressed in HBxAg-positive cells, HepG2 cells were stably transfected with HBxAg, and then with pZeoSV2 or pZeoSV2-I kappa B alpha. When RNAs from each culture were compared by PCR-select cDNA subtraction, fibronectin (FN) mRNA was shown to be strongly down-regulated by I kappa B alpha. Up-regulated expression of FN and co-expression between FN and HBxAg were observed in liver sections from HBV carriers that were stained for HBxAg and analysed for FN mRNA by in situ hybridization (ISH). In liver cell cultures, HBxAg increased the levels of FN mRNA and protein. This was because of the HBxAg-mediated trans-activation of the FN promoter, which was NF-kappa B-dependent. HBxAg also antagonized the repression of the FN promoter by the tumour suppressor, p53. Hence, the FN gene may be a natural target for HBxAg trans-activation, perhaps through activation of NF-kappa B and inactivation of p53, thereby contributing to the accumulation of FN in the liver over the course of chronic HBV infection.
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Affiliation(s)
- P A Norton
- Department of Biochemistry and Molecular Pharmacology, Jefferson Center for Biomedical Research, Thomas Jefferson University, Philadelphia, PA 18901, USA.
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Chen HY, Tang NH, Li XJ, Zhang SJ, Chen ZX, Wang XZ. Transfection and expression of hepatitis B virus x gene and its effect on apoptosis in HL-7702 cells. World J Gastroenterol 2004; 10:959-64. [PMID: 15052674 PMCID: PMC4717112 DOI: 10.3748/wjg.v10.i7.959] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIM: To investigate the effects of hepatitis B virus x gene and its protein product HBxAg on apoptosis in hepatocyte line HL-7702.
METHODS: The reconstituted plasmid pcDNA3-x was established through recombination DNA technique; pcDNA3-X was transfected into HL-7702 cells by lipid-mediated trasfection. Positive clones were screened by G418, and HL-7702/HBx cells were analysed by the RT-PCR to confirm the steady expression of X gene in HL-7702 cells. The apoptosis rate in HL-7702 cells was determined by flow cytometry, TUNEL technology, electronic microscope. At the mean time, pcDNA3-X was transfected transiently into HL-7702 cells, and total RNA from HL-7702 cells was extracted 24, 48, 72, 96 and 120 h after the transient transfection, and semi-quantitative analysis was performed by RT-PCR to detect the expression of HBV X gene. Furthermore, apoptosis rate in HL-7702 cells was determined by flow cytometry analysis at the different times.
RESULTS: RT-PCR analysis showed that HBV X gene could be expressed stably in HL-7702 cells. Both flow cytometry and TUNEL technology revealed that the apoptosis rates of HL-7702/HBx cells were much higher than those of HL-7702/ pcDNA3 and HL-7702 cells. Furthermore, the apoptotic phenomena and apoptotic body were observed in HL-7702/ HBx cells under electronic microscope, but not in HL-7702/ pcDNA3 and HL-7702 cells. In the experiment of transient transfection, RT-PCR reveals that X gene was expressed most at 72 h after transfection; and the apoptosis rate reached the highest at the same time. After that, the apoptosis rate was reduced with the decrease of the X gene expression.
CONCLUSION: HBV X gene and X protein can promote the apoptosis in hepatocyte. And there exist a quantity-effect relationship between the X gene expression and apoptosis rate in hepatocyte.
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Affiliation(s)
- Hong-Ying Chen
- Department of Gastroenterology, Union Hospital, Fujian Medical University, Fuzhou 350001, Fujian Province, China.
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Pan J, Clayton M, Feitelson MA. Hepatitis B virus X antigen promotes transforming growth factor-beta1 (TGF-beta1) activity by up-regulation of TGF-beta1 and down-regulation of alpha2-macroglobulin. J Gen Virol 2004; 85:275-282. [PMID: 14769885 DOI: 10.1099/vir.0.19650-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Hepatitis B virus (HBV) X antigen (HBxAg) may contribute to the development of hepatocellular carcinoma (HCC) by activation of signalling pathways such as NF-kappaB. To identify NF-kappaB target genes differentially expressed in HBxAg-positive compared to -negative cells, HepG2 cells consistently expressing HBxAg (HepG2X cells) were stably transfected with pZeoSV2 or pZeoSV2-IkappaBalpha. mRNA from each culture was isolated and compared by PCR select cDNA subtraction. The results showed lower levels of alpha(2)-macroglobulin (alpha(2)-M) in HepG2X-pZeoSV2 compared to HepG2X-pZeoSV2-IkappaBalpha cells. This was confirmed by Northern and Western blotting, and by measurement of extracellular alpha(2)-M levels. Elevated transforming growth factor-beta1 (TGF-beta1) levels were also seen in HepG2X compared to control cells. Serum-free conditioned medium (SFCM) from HepG2X cells suppressed DNA synthesis in a TGF-beta-sensitive cell line, Mv1Lu. The latter was reversed when the SFCM was pretreated with exogenous, activated alpha(2)-M or with anti-TGF-beta. Since elevated TGF-beta1 promotes the development of many tumour types, these observations suggest that the HBxAg-mediated alteration in TGF-beta1 and alpha(2)-M production may contribute importantly to the pathogenesis of HCC.
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Affiliation(s)
- Jingbo Pan
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Room 222 Alumni Hall, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Marcy Clayton
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Room 222 Alumni Hall, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Mark A Feitelson
- Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Room 222 Alumni Hall, 1020 Locust Street, Philadelphia, PA 19107, USA
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Chen HY, Tang NH, Zhang SJ, Chen ZX, Wang XZ. Construction of hepatitis B virus X gene expression vector in eucaryotic cells and its transfection in HL-7702 cells. Shijie Huaren Xiaohua Zazhi 2004; 12:614-617. [DOI: 10.11569/wcjd.v12.i3.614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To establish a human hepatocyte cell line which can express hepatitis B virus (HBV) X gene.
METHODS: HBV X gene was obtained through PCR techn-ology. After A-tailing added, X gene was connected into vector PUCmT. Vector PUCmT-X and PcDNA3 were digested with EcoRI and HindIII. The fragments of X and PcDNA3 were connected to establish reconstituted plasmid PcDNA3-X. Then PcDNA3-X and PcDNA3 were transfected into HL-7702 cells by lipid-mediated transfection. After selected with G418, HL-7702/HBx cells were analysed by the reverse transcription-PCR to confirm the steady expression of X gene in HL-7702.
RESULTS: Reconstituted plasmid PcDNA3-X included the anticipated fragment of HBV X gene was proved by auto-sequencing assay. RT-PCR analysis showed that reconstituted plasmid PcDNA3-X could express the X protein efficiently in HL-7702 cells.
CONCLUSION: Hepatocyte can express HBV X gene, which is an ideal model to study the effect of HBV X gene on the development of hepatitis and hepatocelular carcinoma.
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Wei R, Xia ZL, Chen B, Han JJ, Ren DL, Yang MF. CD14 + cell dysfunction in patients with chronic active hepatitis B. Shijie Huaren Xiaohua Zazhi 2004; 12:618-621. [DOI: 10.11569/wcjd.v12.i3.618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To study the functional states of CD14+ cells in peripheral blood mononuclear cell (PBMCs) by analyzing the expression of early active antigen, production of pro-inflammatory cytokines and phagocytosis with flow cytometry (FCM).
METHODS: PBMCs were isolated from 11 patients with chronic active hepatitis B and 10 healthy blood donors, and 4-color flow cytometry and gate setting techniques were applied. The percentage of CD14+ cells and level of CD14 antigen were tested by FCM, after gate setting with CD14, side scatter (SSC) and activation-linked surface antigen (CD69) expression rate, percentage of TNF-α producing cells, level of intro-cellular TNF-α, the percentage of phagocytes and the ability of phagocytosis were investigated.
RESULTS: The SSC mean value of CD14+ cell of HBV patients was higher than that of health control (P < 0.01); There were no difference between two testing groups on the percentage of CD14+ cells and level of CD14 antigen, however the level of CD14 antigen was positively associated with the percentage of CD14+ cells. CD14/69 double expression rate was significantly higher than that of control group (P < 0.01); No difference was observed on CD14/TNF-α double stain cells between testing groups; In comparison with control group, the level of cellular TNF-α in HBV group was higher (P < 0.05). In control group, the percentage of TNF-α producing cells were correlated with SSC value and number of phagocytes that expressed CD14/69. There was no difference in phagocytes that expressed CD14/69 in two groups. As compared with the control group, there was more phagocytostic CD14+ cells in HBV group (P < 0.01), but the mean phagocytosis amount was significantly lower in this group (P < 0.05), and the number of phagocyte was negatively correlated with the level of CD14 antigen; while the SSC value and number of TNF-αproducing cells were negatively correlated with level of CD14 antigen.
CONCLUSION: CD14+ cells in PBMCs from chronic active hepatitis B patients are over activated in a dysfunction stage.
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Wang JH, Yun C, Kim S, Lee JH, Yoon G, Lee MO, Cho H. Reactive oxygen species modulates the intracellular level of HBx viral oncoprotein. Biochem Biophys Res Commun 2003; 310:32-9. [PMID: 14511644 DOI: 10.1016/j.bbrc.2003.08.113] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
HBx (hepatitis B virus X) viral oncoprotein is a multifunctional protein of which the cellular level may be one of the important factors in determining HBV-mediated pathological progression of liver diseases, chronic hepatitis, and hepatocellular carcinoma. Our previous work revealed that adriamycin, a chemotherapeutic agent, caused a marked increase in the intracellular level of HBx by retarding its rapid degradation. In the present study, modulation of HBx expression was found to be confined to adriamycin but not to other chemotherapeutic agents, cisplatin and 5-fluorouracil. Interestingly, adriamycin caused a rapid increase of reactive oxygen species (ROS) and its accumulation continued until 24h. In contrast, two other agents had little effect on ROS generation, suggesting the possible involvement of ROS in the HBx regulation. In fact, direct addition of H(2)O(2) to the cells significantly increased the level of HBx protein in HBx-expressing ChangX-34 cells as well as in hepatitis B virus-related hepatoma cells, PLC/PRF/5 and HepG2.2.15 cells. Furthermore, antioxidants, N-acetyl-cysteine and pyrrolidinedithiocarbamate (PDTC), completely abolished the increase of HBx protein induced by adriamycin, indicating that adriamycin modulates the intracellular HBx level via ROS generation. Together, these findings provide a novel aspect of HBx regulation by cellular ROS level. Therefore, intracellular microenvironments generating ROS such as severe inflammation may aggravate the pathogenesis of liver disease by accumulating the HBx level.
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Affiliation(s)
- Jin-Hee Wang
- Department of Biochemistry, Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, 5 Wonchon-dong, Paldal-gu, Suwon 442-741, Republic of Korea
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Kaplan DE, Reddy KR. Rising incidence of hepatocellular carcinoma: the role of hepatitis B and C; the impact on transplantation and outcomes. Clin Liver Dis 2003; 7:683-714. [PMID: 14509534 DOI: 10.1016/s1089-3261(03)00060-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hepatocellular carcinoma caused by hepatitis B and hepatitis C are global scourges but are likely to peak in incidence in the next 2 decades and then decline. Universal vaccination has been effective in stemming the incidence of chronic hepatitis B and early-onset HCC in regions of high endemicity where implemented, but preventive measures in HCV are not yet available. After the attrition of older affected generations, the incidence of HCC will likely decline rapidly. While no vaccine is currently available for hepatitis C, cases are projected to peak and decline because of a marked reduction in transmission as a result of behavioral modification and safeguarding of blood supplies. Until these epidemiologic projections come to pass, management of hepatocellular carcinoma will continue to become a progressively more frequently encountered clinical challenge. Therapy for chronic hepatitis may ameliorate but will not eliminate the development of tumors. The demand for orthotopic liver transplantation will continue to climb, and palliative therapies for non-resectable cases will require studies aimed at optimization of benefit. LDLT may remain an option for high-risk patients affording tumor-free survival for some otherwise terminal patients.
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Affiliation(s)
- David E Kaplan
- Division of Gastroenterology and Hepatology, University of Pennsylvania School of Medicine, 3 Raydin, 3400 Spruce Street, Philadelphia, PA 19104, USA
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Lian Z, Liu J, Li L, Li X, Tufan NLS, Clayton M, Wu MC, Wang HY, Arbuthnot P, Kew M, Feitelson MA. Upregulated expression of a unique gene by hepatitis B x antigen promotes hepatocellular growth and tumorigenesis. Neoplasia 2003; 5:229-44. [PMID: 12869306 PMCID: PMC1502406 DOI: 10.1016/s1476-5586(03)80055-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Hepatitis B x antigen (HB x Ag) is a trans-activating protein that may be involved in hepatocarcinogenesis, although few natural effectors of HB x Ag that participate in this process have been identified. To identify additional effectors, whole cell RNA isolated from HB x Ag-positive and HB x Ag-negative HepG2 cells were compared by polymerase chain reaction select cDNA subtraction, and one clone, upregulated gene, clone 11 (URG11), was chosen for further characterization. Elevated levels of URG11 mRNA and protein were observed in HB x Ag-positive compared to HB x Ag-negative HepG2 cells. Costaining was observed in infected liver (P < 0.01). URG11 stimulated cell growth in culture (P < 0.01), anchorage-independent growth in soft agar (P < 0.001), and accelerated tumor formation (P < 0.01), and yielded larger tumors (P < 0.02) in SCID mice injected subcutaneously with HepG2 cells. These data suggest that URG11 is a natural effector of HB x Ag that may promote the development of hepatocellular carcinoma.
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Affiliation(s)
- Zhaorui Lian
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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Tarn C, Zou L, Hullinger RL, Andrisani OM. Hepatitis B virus X protein activates the p38 mitogen-activated protein kinase pathway in dedifferentiated hepatocytes. J Virol 2002; 76:9763-72. [PMID: 12208955 PMCID: PMC136494 DOI: 10.1128/jvi.76.19.9763-9772.2002] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2002] [Accepted: 06/15/2002] [Indexed: 12/22/2022] Open
Abstract
Hepatitis B virus X protein (pX) is implicated in hepatocarcinogenesis by an unknown mechanism. Employing a cellular model linked to pX-mediated transformation, we investigated the role of the previously reported Stat3 activation by pX in hepatocyte transformation. Our model is composed of a differentiated hepatocyte (AML12) 3pX-1 cell line that undergoes pX-dependent transformation and a dedifferentiated hepatocyte (AML12) 4pX-1 cell line that does not exhibit transformation by pX. We report that pX-dependent Stat3 activation occurs only in non-pX-transforming 4pX-1 cells and conclude that Stat3 activation is not linked to pX-mediated transformation. Maximum Stat3 transactivation requires Ser727 phosphorylation, mediated by mitogenic pathway activation. Employing dominant negative mutants and inhibitors of mitogenic pathways, we demonstrate that maximum, pX-dependent Stat3 transactivation is inhibited by the p38 mitogen-activated protein kinase (MAPK)-specific inhibitor SB 203580. Using transient-transreporter and in vitro kinase assays, we demonstrate for the first time that pX activates the p38 MAPK pathway only in 4pX-1 cells. pX-mediated Stat3 and p38 MAPK activation is Ca(2+) and c-Src dependent, in agreement with the established cellular action of pX. Importantly, pX-dependent activation of p38 MAPK inactivates Cdc25C by phosphorylation of Ser216, thus initiating activation of the G(2)/M checkpoint, resulting in 4pX-1 cell growth retardation. Interestingly, pX expression in the less differentiated hepatocyte 4pX-1 cells activates signaling pathways known to be active in regenerating hepatocytes. These results suggest that pX expression in the infected liver effects distinct mitogenic pathway activation in less differentiated versus differentiated hepatocytes.
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Affiliation(s)
- Chi Tarn
- Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana 47904-1246, USA
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Yun C, Lee JH, Wang JH, Seong JK, Oh SH, Yu DY, Cho H. Expression of hepatitis B virus X (HBx) gene is up-regulated by adriamycin at the post-transcriptional level. Biochem Biophys Res Commun 2002; 296:1157-63. [PMID: 12207895 DOI: 10.1016/s0006-291x(02)02058-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Hepatitis B virus (HBV) X protein (HBx) is thought to be involved in the development of liver cancer and alteration of cellular HBx level may influence the pathological progression of HBV-induced liver diseases. We found that the cellular levels of HBx mRNA transcript and protein in cells were greatly enhanced by adriamycin, a topoisomerase II inhibitor. Up-regulation of HBx mRNA by adriamycin was also observed in HBx transgenic mice, which was accompanied with a significant increase of VEGF mRNA, the downstream target of HBx. When we investigated the underlying mechanism, we found that half-life of HBx mRNA in HBx-expressing Chang cells was about 3h, but was prolonged to >6h in the presence of adriamycin. Moreover, half-life of rapidly degrading HBx protein was determined as about 15min however, it remained almost constant until 60min in the presence of adriamycin. These results provide the first evidence that the cellular level of HBx gene can be increased at the post-transcriptional level.
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Affiliation(s)
- Chawon Yun
- Department of Biochemistry, Ajou University School of Medicine, 5 Wonchon-dong, Paldal-ku, 442-749, Suwon, Republic of Korea
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