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Kang I, Kim JA, Kim J, Lee JH, Kim MJ, Ahn JK. Hepatitis B virus X protein promotes epithelial-mesenchymal transition of hepatocellular carcinoma cells by regulating SOCS1. BMB Rep 2022. [PMID: 35168698 PMCID: PMC9152579 DOI: 10.5483/bmbrep.2022.55.5.157] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hepatocellular carcinoma (HCC), a primary type of liver cancer, is one of the leading causes of cancer related deaths worldwide. HCC patients have poor prognosis due to intrahepatic and extrahepatic metastasis. Hepatitis B virus (HBV) infection is one of the major causes of various liver diseases including HCC. Among HBV gene products, HBV X protein (HBx) plays an important role in the development and metastasis of HCC. However, the mechanism of HCC metastasis induced by HBx has not been elucidated yet. In this study, for the first time, we report that HBx interacts with the suppressor of cytokine signaling 1 (SOCS1) which negatively controls NF-κB by degrading p65, a subunit of NF-κB. NF-κB activates the transcription of factors associated with epithelial-mesenchymal transition (EMT), a crucial cellular process associated with invasiveness and migration of cancer cells. Here, we report that HBx physically binds to SOCS1, subsequently prevents the ubiquitination of p65, activates the transcription of EMT transcription factors and enhance cell migration and invasiveness, suggesting a new mechanism of HBV-associated HCC metastasis.
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Affiliation(s)
- Inho Kang
- Department of Microbiology & Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
| | - Ji Ae Kim
- Department of Microbiology & Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
| | - Jinchul Kim
- Department of Microbiology & Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
| | - Ju Hyeon Lee
- Department of Microbiology & Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
| | - Mi-jee Kim
- Department of Microbiology & Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
| | - Jeong Keun Ahn
- Department of Microbiology & Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
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Kang I, Kim JA, Kim J, Lee JH, Kim MJ, Ahn JK. Hepatitis B virus X protein promotes epithelial-mesenchymal transition of hepatocellular carcinoma cells by regulating SOCS1. BMB Rep 2022; 55:220-225. [PMID: 35168698 PMCID: PMC9152579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 11/15/2021] [Accepted: 12/26/2021] [Indexed: 03/08/2024] Open
Abstract
Hepatocellular carcinoma (HCC), a primary type of liver cancer, is one of the leading causes of cancer related deaths worldwide. HCC patients have poor prognosis due to intrahepatic and extrahepatic metastasis. Hepatitis B virus (HBV) infection is one of the major causes of various liver diseases including HCC. Among HBV gene products, HBV X protein (HBx) plays an important role in the development and metastasis of HCC. However, the mechanism of HCC metastasis induced by HBx has not been elucidated yet. In this study, for the first time, we report that HBx interacts with the suppressor of cytokine signaling 1 (SOCS1) which negatively controls NF-κB by degrading p65, a subunit of NF-κB. NF-κB activates the transcription of factors associated with epithelial-mesenchymal transition (EMT), a crucial cellular process associated with invasiveness and migration of cancer cells. Here, we report that HBx physically binds to SOCS1, subsequently prevents the ubiquitination of p65, activates the transcription of EMT transcription factors and enhance cell migration and invasiveness, suggesting a new mechanism of HBV-associated HCC metastasis. [BMB Reports 2022; 55(5): 220-225].
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Affiliation(s)
- Inho Kang
- Department of Microbiology & Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
| | - Ji Ae Kim
- Department of Microbiology & Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
| | - Jinchul Kim
- Department of Microbiology & Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
| | - Ju Hyeon Lee
- Department of Microbiology & Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
| | - Mi-jee Kim
- Department of Microbiology & Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
| | - Jeong Keun Ahn
- Department of Microbiology & Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
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Hepatitis B Viral Protein HBx and the Molecular Mechanisms Modulating the Hallmarks of Hepatocellular Carcinoma: A Comprehensive Review. Cells 2022; 11:cells11040741. [PMID: 35203390 PMCID: PMC8870387 DOI: 10.3390/cells11040741] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/10/2022] [Accepted: 02/16/2022] [Indexed: 02/06/2023] Open
Abstract
With 296 million cases estimated worldwide, chronic hepatitis B virus (HBV) infection is the most common risk factor for hepatocellular carcinoma (HCC). HBV-encoded oncogene X protein (HBx), a key multifunctional regulatory protein, drives viral replication and interferes with several cellular signalling pathways that drive virus-associated hepatocarcinogenesis. This review article provides a comprehensive overview of the role of HBx in modulating the various hallmarks of HCC by supporting tumour initiation, progression, invasion and metastasis. Understanding HBx-mediated dimensions of complexity in driving liver malignancies could provide the key to unlocking novel and repurposed combinatorial therapies to combat HCC.
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Abdoli A, Nakhaie M, Feizi N, Salimi Jeda A, Ramezani A. Harmonized Autophagy Versus Full-Fledged Hepatitis B Virus: Victorious or Defeated. Viral Immunol 2019; 32:322-334. [PMID: 31483214 DOI: 10.1089/vim.2019.0042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Autophagy is a finely tuned process in the regulation of innate immunity to avoid excessive inflammatory responses and inflammasome signaling. In contrast, the results of recent studies have shown that autophagy may disease-dependently contribute to the pathogenesis of liver diseases, such as fibrosis, cirrhosis, and hepatocellular carcinoma (HCC) during hepatitis B virus (HBV) infection. HBV has learned to subvert the cell's autophagic machinery to promote its replication. Given the great impact of the autophagy mechanism on the HBV infection and HCC, recognizing these factors may be offered new hope for human intervention and treatment of chronic HBV. This review focuses on recent findings viewing the dual role of autophagy plays in the pathogenesis of HBV infected hepatocytes.
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Affiliation(s)
- Asghar Abdoli
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran
| | - Mohsen Nakhaie
- Department of Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Neda Feizi
- Dipartimento di Medicina Interna e Specialità Mediche, Sapienza Università di Roma, Rome, Italy
| | - Ali Salimi Jeda
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Amitis Ramezani
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran
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Kranidioti H, Manolakopoulos S, Kontos G, Breen MS, Kourikou A, Deutsch M, Quesada-Del-Bosque ME, Martinez-Nunez RT, Naiyer MM, Woelk CH, Sanchez-Elsner T, Hadziyannis E, Papatheodoridis G, Khakoo SI. Immunological biomarkers as indicators for outcome after discontinuation of nucleos(t)ide analogue therapy in patients with HBeAg-negative chronic hepatitis B. J Viral Hepat 2019; 26:697-709. [PMID: 30702196 DOI: 10.1111/jvh.13068] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 01/09/2019] [Indexed: 02/07/2023]
Abstract
The optimal duration of treatment with nucleos(t)ide analogues (NAs) for patients with HBeAg-negative chronic hepatitis B (CHB) is unknown. The aim of this study was to identify an immune signature associated with off-treatment remission to NA therapy. We performed microarray analysis of peripheral blood mononuclear cell (PBMCs) from six patients with chronic hepatitis B who stopped NA therapy (three with off-treatment remission, three with relapse) and five patients with chronic HBV infection (previously termed 'inactive carriers') served as controls. Results were validated using qRT-PCR on a second group of 21 individuals (17 patients who stopped treatment and four controls). PBMCs from 38 patients on long-term NA treatment were analysed for potential to stop treatment. Microarray analysis indicated that patients with off-treatment remission segregated as a distinct out-group. Twenty-one genes were selected for subsequent validation. Ten of these were expressed at significantly lower levels in the patients with off-treatment remission compared to the patients with relapse and predicted remission with AUC of 0.78-0.92. IFNγ, IL-8, FASLG and CCL4 were the most significant by logistic regression. Twelve (31.6%) of 38 patients on long-term NA therapy had expression levels of all these four genes below cut-off values and hence were candidates for stopping treatment. Our data suggest that patients with HBeAg-negative CHB who remain in off-treatment remission 3 years after NA cessation have a distinct immune signature and that PBMC RNA levels of IFNγ, IL-8, FASLG and CCL4 may serve as potential biomarkers for stopping NA therapy.
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Affiliation(s)
- Hariklia Kranidioti
- Department of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.,2nd Academic Department of Internal Medicine, Hippokration General Hospital of Athens, Athens, Greece
| | - Spilios Manolakopoulos
- 2nd Academic Department of Internal Medicine, Hippokration General Hospital of Athens, Athens, Greece.,Academic Department of Gastroenterology, Laiko General Hospital of Athens, Athens, Greece
| | - George Kontos
- 2nd Academic Department of Internal Medicine, Hippokration General Hospital of Athens, Athens, Greece
| | - Michael S Breen
- Department of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Anastasia Kourikou
- 2nd Academic Department of Internal Medicine, Hippokration General Hospital of Athens, Athens, Greece
| | - Melanie Deutsch
- 2nd Academic Department of Internal Medicine, Hippokration General Hospital of Athens, Athens, Greece
| | | | - Rocio T Martinez-Nunez
- Department of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Mohammed M Naiyer
- Department of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Christopher H Woelk
- Department of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Tilman Sanchez-Elsner
- Department of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Emilia Hadziyannis
- Academic Department of Gastroenterology, Laiko General Hospital of Athens, Athens, Greece
| | - George Papatheodoridis
- Academic Department of Gastroenterology, Laiko General Hospital of Athens, Athens, Greece
| | - Salim I Khakoo
- Department of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
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6
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Zhang Q, Lou Y, Bai XL, Liang TB. Immunometabolism: A novel perspective of liver cancer microenvironment and its influence on tumor progression. World J Gastroenterol 2018; 24:3500-3512. [PMID: 30131656 PMCID: PMC6102497 DOI: 10.3748/wjg.v24.i31.3500] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 05/29/2018] [Accepted: 06/27/2018] [Indexed: 02/06/2023] Open
Abstract
The initiation and progression of liver cancer, including hepatocellular carcinoma and intrahepatic cholangiocarcinoma, are dependent on its tumor microenvironment. Immune cells are key players in the liver cancer microenvironment and show complicated crosstalk with cancer cells. Emerging evidence has shown that the functions of immune cells are closely related to cell metabolism. However, the effects of metabolic changes of immune cells on liver cancer progression are largely undefined. In this review, we summarize the recent findings of immunometabolism and relate these findings to liver cancer progression. We also explore the translation of the understanding of immunometabolism for clinical use.
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Affiliation(s)
- Qi Zhang
- Department of Hepatobiliary and Pancreatic Surgery, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Key Laboratory of Pancreatic Disease, Hangzhou 310009, Zhejiang Province, China
| | - Yu Lou
- Department of Hepatobiliary and Pancreatic Surgery, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Key Laboratory of Pancreatic Disease, Hangzhou 310009, Zhejiang Province, China
| | - Xue-Li Bai
- Department of Hepatobiliary and Pancreatic Surgery, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Key Laboratory of Pancreatic Disease, Hangzhou 310009, Zhejiang Province, China
| | - Ting-Bo Liang
- Department of Hepatobiliary and Pancreatic Surgery, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, Zhejiang Province, China
- Zhejiang Provincial Key Laboratory of Pancreatic Disease, Hangzhou 310009, Zhejiang Province, China
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7
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HBV infection increases the risk of macular degeneration: the roles of HBx-mediated sensitization of retinal pigment epithelial cells to UV and blue light irradiation. J Transl Med 2018; 16:221. [PMID: 30097062 PMCID: PMC6086029 DOI: 10.1186/s12967-018-1594-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 08/02/2018] [Indexed: 11/29/2022] Open
Abstract
Background Hepatitis B virus (HBV) infection is strongly associated with hepatocellular carcinoma due to the main pathogenic X protein of HBV (HBx). Whether HBV infection and the HBx protein could result in macular degeneration (MD) is not known. The aim of this study is to assess the association and underlying mechanisms between HBV infection and MD. Methods The National Health Research Institutes in Taiwan built a large database, the National Health Insurance Research Database (NHIRD), which includes the claims data from the Taiwan National Health Insurance (NHI) program. The Taiwan NHI is a single-payer, compulsory health insurance program for Taiwan citizens. The data for the present study were derived from the Longitudinal Health Insurance Database, which contains the claims data of 1 million insured people within the NHIRD, including beneficiary registration, inpatient and outpatient files, drug use, and other medical services. In this study, we first investigated the association of HBV infection and the risk of MD by a population-based cohorts study enrolling 39,796 HBV-infected patients and 159,184 non-HBV-infected patients. Results After adjustment of age, sex, and comorbidities, the risk of MD was significantly higher in the HBV-infected cohort than in the non-HBV-infected cohort (adjusted HR = 1.31; 95% CI = 1.17–1.46). In vitro, we provided evidence to demonstrate that overexpression of HBx in the human retinal pigment epithelial (RPE) cell line, ARPE19, significantly reduced cell viability and clonogenic survival upon UV and blue light irradiation. By gene microarray analysis, we further showed that almost all genes in DNA repair pathways including base excision repair, nucleotide excision repair, mismatch repair, and homologous recombination were significantly down-regulated in the UV-induced cell death of HBx-transfected ARPE19 cells. Conclusions The HBx protein may sensitize RPE cells to UV and blue light irradiation and increase the risk of HBV-infection-associated MD through down-regulation of multiple DNA repair pathways. Electronic supplementary material The online version of this article (10.1186/s12967-018-1594-4) contains supplementary material, which is available to authorized users.
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Fu S, Zhou RR, Li N, Huang Y, Fan XG. Hepatitis B virus X protein in liver tumor microenvironment. Tumour Biol 2016; 37:10.1007/s13277-016-5406-2. [PMID: 27658781 PMCID: PMC5250643 DOI: 10.1007/s13277-016-5406-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 09/13/2016] [Indexed: 12/18/2022] Open
Abstract
Encoded by the hepatitis B virus, hepatitis B virus X protein (HBx) is a multifunctional, potentially oncogenic protein that acts primarily during the progression from chronic hepatitis B to cirrhosis and hepatocellular carcinoma (HCC). In recent decades, it has been established that chronic inflammation generates a tumor-supporting microenvironment. HCC is a typical chronic inflammation-related cancer, and inflammation is the main risk factor for HCC progression. The viral transactivator HBx plays a pivotal role in the initiation and maintenance of hepatic inflammatory processes through interactions with components of the tumor microenvironment including tumor cells and the surrounding peritumoral stroma. The complex interactions between HBx and this microenvironment are thought to regulate tumor growth, progression, invasion, metastasis, and angiogenesis. In this review, we have summarized the current evidence evaluating the function of HBx and its contribution to the inflammatory liver tumor microenvironment.
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Affiliation(s)
- Sha Fu
- Department of Infectious Diseases, Key Laboratory of Viral Hepatitis of Hunan Province, Xiangya Hospital, Central South University, P. O. Box: 410008, Changsha, China
| | - Rong-Rong Zhou
- Department of Infectious Diseases, Key Laboratory of Viral Hepatitis of Hunan Province, Xiangya Hospital, Central South University, P. O. Box: 410008, Changsha, China.
| | - Ning Li
- Department of Blood Transfusion, Xiangya Hospital, Central South University, Changsha, China
| | - Yan Huang
- Department of Infectious Diseases, Key Laboratory of Viral Hepatitis of Hunan Province, Xiangya Hospital, Central South University, P. O. Box: 410008, Changsha, China
| | - Xue-Gong Fan
- Department of Infectious Diseases, Key Laboratory of Viral Hepatitis of Hunan Province, Xiangya Hospital, Central South University, P. O. Box: 410008, Changsha, China.
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9
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Chao CCK. Inhibition of apoptosis by oncogenic hepatitis B virus X protein: Implications for the treatment of hepatocellular carcinoma. World J Hepatol 2016; 8:1061-1066. [PMID: 27660672 PMCID: PMC5026997 DOI: 10.4254/wjh.v8.i25.1061] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/27/2016] [Accepted: 07/22/2016] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B virus X protein (HBx) plays an important role in the development of hepatocellular carcinoma (HCC). In addition, hepatoma upregulated protein (HURP) is a cellular oncogene that is upregulated in a majority of HCC cases. We highlight here recent findings demonstrating a link between HBx, HURP and anti-apoptosis effects observed in cisplatin-treated HCC cells. We observed that Hep3B cells overexpressing HBx display increased HURP mRNA and protein levels, and show resistance to cisplatin-induced apoptosis. Knockdown of HURP in HBx-expressing cells reverses this effect, and sensitizes cells to cisplatin. The anti-apoptotic effect of HBx requires activation of the p38/MAPK pathway as well as expression of SATB1, survivin and HURP. Furthermore, silencing of HURP using short-hairpin RNA promotes accumulation of p53 and reduces cell proliferation in SK-Hep-1 cells (p53+/–), whereas these effects are not observed in p53-mutant Mahlavu cells. Similarly, HURP silencing does not affect the proliferation of H1299 lung carcinoma cells or Hep3B HCC cells which lack p53. Silencing of HURP sensitizes SK-Hep-1 cells to cisplatin. While HURP overexpression promotes p53 ubiquitination and degradation by the proteasome, HURP silencing reverses these effects. Inoculation of SK-Hep-1 cancer cells in which HURP has been silenced produces smaller tumors than control in nude mice. Besides, gankyrin, a positive regulator of the E3 ubiquitin ligase MDM2, is upregulated following HURP expression, and silencing of gankyrin reduces HURP-mediated downregulation of p53. In addition, we observed a positive correlation between HURP and gankyrin protein levels in HCC patients (r2 = 0.778; n = 9). These findings suggest a role for the viral protein HBx and the host protein HURP in preventing p53-mediated apoptosis during cancer progression and establishment of chemoresistance.
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Dong Y, Shen X, He M, Wu Z, Zheng Q, Wang Y, Chen Y, Wu S, Cui J, Zeng Z. Activation of the JNK-c-Jun pathway in response to irradiation facilitates Fas ligand secretion in hepatoma cells and increases hepatocyte injury. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2016; 35:114. [PMID: 27431384 PMCID: PMC4950705 DOI: 10.1186/s13046-016-0394-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 07/11/2016] [Indexed: 01/09/2023]
Abstract
Background It is well established that some irradiated liver non-parenchymal cells secrete pro-inflammatory cytokines to facilitate the development of radiation-induced liver disease. However, little is known on whether the irradiated hepatoma cells-mediated non-irradiated hepatocyte injury occurs in HCC patients. Here, we elucidated the roles of the irradiated hepatoma cells in driving non-irradiated hepatocyte injury and its underlying mechanism. Methods SMMC7721 cells were cultured and divided into irradiated (4-Gy X-ray, R) and non-irradiated (NR) groups. At 24th hour after irradiation, conditioned medium (CM) from these cultures was mixed with normal culture medium in specific proportions, and termed as 7721-R-CM and 7721-NR-CM. Following incubation with these CM compound, the biological characteristics of L02 cells related to liver cell injury including viability, apoptosis and liver dysfunction indices were comparatively analyzed. Simultaneously, the levels of proliferation- and apoptosis-related cytokines in irradiated and non-irradiated SMMC7721 cells were also measured. FasL as a cytokine with significantly differential expression, was selected to clarify its effects on L02 apoptosis. Subsequently, FasL expression following irradiation was examined in SMMC7721 and other HCC cells with varying malignant potentials, as well as in HCC tissues, the related mechanism of higher expression of FasL in irradiated HCC cells was further investigated. Results Apoptosis and liver dysfunction indices were all significantly enhanced in L02 cells treated with 7721-R-CM, whereas viability was suppressed, compared to those with 7721-NR-CM stimulation. FasL was identified as a leading differential cytokine in the irradiated SMMC7721 cells. Higher proportion of apoptosis was also found in L02 cells following FasL incubation. A recombinant Fas-Fc protein, which blocks Fas-FasL interaction, ameliorated 7721-R-CM-induced apoptosis in L02 cells. FasL was highly expressed in a dose-dependent manner, and peaked at the 24th hour post-irradiation in different HCC cells and their culture supernatant. Meanwhile, phosphorylation levels of JNK, ERK, Akt, and p38 were all upregulated significantly in irradiated HCC cells. But, only JNK inhibition was validated to block radiation-induced FasL expression in HCC cells. c-Jun, the target transcription factor of JNK, was also activated. Conclusion In HCC cells, the JNK-c-Jun pathway plays an important role in mediating irradiation- induced FasL expression, which may be critical in determining non-irradiated hepatocyte injury. Electronic supplementary material The online version of this article (doi:10.1186/s13046-016-0394-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yinying Dong
- Department of Radiation Oncology, Zhongshan Hospital, Fudan University, 180 Feng Lin Road, Shanghai, 200032, People's Republic of China
| | - Xiaoyun Shen
- Department of Radiation Oncology, Zhongshan Hospital, Fudan University, 180 Feng Lin Road, Shanghai, 200032, People's Republic of China
| | - Mingyan He
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, 180 Feng Lin Road, Shanghai, 200032, People's Republic of China
| | - Zhifeng Wu
- Department of Radiation Oncology, Zhongshan Hospital, Fudan University, 180 Feng Lin Road, Shanghai, 200032, People's Republic of China
| | - Qiongdan Zheng
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, 180 Feng Lin Road, Shanghai, 200032, People's Republic of China
| | - Yaohui Wang
- Department of Radiology, Shanghai Cancer Center, Fudan University, Shanghai, 200032, People's Republic of China
| | - Yuhan Chen
- Department of Radiation Oncology, Zhongshan Hospital, Fudan University, 180 Feng Lin Road, Shanghai, 200032, People's Republic of China
| | - Sifan Wu
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, 180 Feng Lin Road, Shanghai, 200032, People's Republic of China
| | - Jiefeng Cui
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, 180 Feng Lin Road, Shanghai, 200032, People's Republic of China.
| | - Zhaochong Zeng
- Department of Radiation Oncology, Zhongshan Hospital, Fudan University, 180 Feng Lin Road, Shanghai, 200032, People's Republic of China.
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11
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Fu S, Fan XG. Pathophysiological implications of hepatitis B X protein in tumor microenvironment of hepatocellular carcinoma. Shijie Huaren Xiaohua Zazhi 2016; 24:1477-1484. [DOI: 10.11569/wcjd.v24.i10.1477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B X protein (HBx), encoded by hepatitis B virus (HBV), is a multifunctional and potentially oncogenic protein that has significant functions during the progression from chronic hepatitis B to cirrhosis and eventually to hepatocellular carcinoma (HCC). Over the past decades, it has been widely established that chronic inflammation orchestrates a tumor-supporting microenvironment. HCC is a typical chronic inflammation-related cancer and inflammation is the main risk factor for the progression of HCC. As a major viral transactivator, HBx is thought to play a pivotal role in the activation and maintenance of hepatic inflammatory process through interaction with various components of the tumor microenvironment including tumor cell and surrounding peritumoral stroma. Complex interactions between HBx and these cell types in this microenvironment will regulate tumor growth, progression, metastasis, and angiogenesis. In this review, we mainly summarize the current understanding of HBx and its contribution to the inflammatory tumor microenvironment of HBV-related HCC.
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12
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Kong F, You H, Zhao J, Liu W, Hu L, Luo W, Hu W, Tang R, Zheng K. The enhanced expression of death receptor 5 (DR5) mediated by HBV X protein through NF-kappaB pathway is associated with cell apoptosis induced by (TNF-α related apoptosis inducing ligand) TRAIL in hepatoma cells. Virol J 2015; 12:192. [PMID: 26577955 PMCID: PMC4650207 DOI: 10.1186/s12985-015-0416-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 11/03/2015] [Indexed: 01/28/2023] Open
Abstract
Background HBV X protein (HBX) is associated with cell apoptosis mediated by TNF-α related apoptosis inducing ligand (TRAIL), while the role of HBX on the expressions of TRAIL receptors death receptor 4 (DR4) and DR5 are unclear. In this study, we detected the cell apoptosis induced by TRAIL as well as gene and protein expressions of DR4 and DR5 in Huh-7 cells steadily transfected with HBX (Huh-7-HBX cells). In addition, we investigated the activation of different pathways associated with the expressions of TRAIL receptors in Huh-7-HBX cells. Methods The apoptosis of Huh-7-HBX cells induced by TRAIL was evaluated by flow cytometry analysis. The levels of DR4 and DR5 expression in cells were determined by real-time PCR and western blotting analysis. The activities of JNK pathway and NF-kappaB (NF-κB) pathway were demonstrated by western blotting assay. Results Compared to control cells, the percentage of cell apoptosis was increased in Huh-7-HBX cells. The increased expressions of DR4 and DR5 on gene and protein levels were observed in Huh-7-HBX cells. Further researches suggested that activation of JNK pathway was increased but not involved in the expression of TRAIL receptors in HBX positive cells. The activation of NF-κB pathway increased and was responsible for DR5 expression and cell apoptosis in HBX positive cells. Conclusions These results demonstrate that increased apoptosis induced by TRAIL is associated with increased expression of DR5 that mediated by HBX through NF-κB pathway. This finding provides a critical insight into the mechanism of hepatocyte apoptosis mediated by HBX in HBV infection.
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Affiliation(s)
- Fanyun Kong
- Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, Jiangsu, 221004, China.
| | - Hongjuan You
- Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, Jiangsu, 221004, China.
| | - Jinjin Zhao
- Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, Jiangsu, 221004, China.
| | - Wen Liu
- Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, Jiangsu, 221004, China.
| | - Lei Hu
- Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, Jiangsu, 221004, China.
| | - Wenya Luo
- Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, Jiangsu, 221004, China.
| | - Wei Hu
- Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, Jiangsu, 221004, China.
| | - Renxian Tang
- Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, Jiangsu, 221004, China.
| | - Kuiyang Zheng
- Department of Pathogenic Biology and Immunology, Laboratory of Infection and Immunity, Xuzhou Medical College, 209 Tongshan Road, Xuzhou, Jiangsu, 221004, China.
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Jung SY, Kim YJ. C-terminal region of HBx is crucial for mitochondrial DNA damage. Cancer Lett 2012; 331:76-83. [PMID: 23246371 DOI: 10.1016/j.canlet.2012.12.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 12/04/2012] [Accepted: 12/04/2012] [Indexed: 02/07/2023]
Abstract
HBx is strongly associated with hepatocellular carcinoma development through transcription factor activation and reactive oxygen species (ROSs) production. However, the exact role of HBx during hepatocellular carcinogenesis is not fully understood. Recently, it was reported that C-terminal truncated HBx is associated with tumor metastasis. In the present study, we confirmed that the C-terminal region of HBx is required for ROS production and 8-oxoguanine (8-oxoG) formation, which is considered as a reliable biomarker of oxidative stress. These results suggest ROS production induced by the C-terminal region of HBx leads to mitochondrial DNA damage, which may play a role in HCC development.
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Affiliation(s)
- Seung-Youn Jung
- Department of Molecular Biology, Pusan National University, Busan 609-735, Republic of Korea
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Tang R, Kong F, Hu L, You H, Zhang P, Du W, Zheng K. Role of hepatitis B virus X protein in regulating LIM and SH3 protein 1 (LASP-1) expression to mediate proliferation and migration of hepatoma cells. Virol J 2012; 9:163. [PMID: 22897902 PMCID: PMC3459728 DOI: 10.1186/1743-422x-9-163] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 07/10/2012] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Hepatitis B virus X protein (HBx) has been shown to be responsible for the development of hepatocellular carcinoma (HCC) caused by Hepatitis B virus infection. However, its potential effect on the progression of hepatocellular carcinoma remains yet unclear. LIM and SH3 protein 1 (LASP-1), a focal adhesion protein, is expressed in an up-regulation manner in the HCC tissues. LASP-1 plays an important role in the regulation of proliferation and migration of HCC. In this study, we investigated the effect of LASP-1 involved in HBx-related tumor progression. METHODS LASP-1 levels in the HBx stable transfected HepG2 and Huh-7 cells were detected by RT-PCR and western blot analysis. The cellular localization of LASP-1 was assessed by immunofluorescence analysis. The activity of phosphatidylinositol 3-kinase (PI3-K) pathway was demonstrated by western blot assay. The HBx-expressing cells were transfected with specific small interference RNA (siRNA) against LASP-1. The proliferation and migration ability of cells were evaluated by cell viability assay and plate clone formation assay. The migration ability of cells was detected by transwell assay and wound healing assay. RESULTS RT-PCR and western blot analysis indicated the expression of LASP-1 was increased in the stable HBx-expressing cells compared with the control cells. Immunofluorescence study revealed that the distributions of LASP-1 in HepG2-HBX cells were mainly in pseudopods and the cytoplasm while they were mainly localized in the cytoplasm of HepG2-Mock cells. The cellular localizations of LASP-1 in Huh-7-HBX cells were in the perinuclear fractions while they were mainly localized in the cytoplasm of Huh-7-Mock cells. The upregulation of LASP-1 was inhibited after treatment with LY294002, PI3-K pathway inhibitor. Overexpression of LASP-1 in the stable HBx-expressing cells enhanced the proliferation and migration ability of hepatocellular cells. siRNA-mediated LASP-1 knowdown in the stable HBx-expressing cells significantly suppressed hepatocellular cells proliferation and migration. CONCLUSIONS These results demonstrated that HBx could upregulate LASP-1 through PI3-K pathway to promote the proliferation and migration of hepatoma cells.
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Affiliation(s)
- Renxian Tang
- Department of Pathogenic biology and Laboratory of Infection and Immunology, Xuzhou Medical College, 84 West Huaihai Road, Xuzhou 221002, Jiangsu Province, China
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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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Ma J, Sun T, Park S, Shen G, Liu J. The role of hepatitis B virus X protein is related to its differential intracellular localization. Acta Biochim Biophys Sin (Shanghai) 2011; 43:583-8. [PMID: 21693548 DOI: 10.1093/abbs/gmr048] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Chronic hepatitis B virus (HBV) infection has been strongly associated with hepatocellular carcinoma. HBV encodes an oncogenic hepatitis B virus X protein (HBx), which is a multifunctional regulator that modulates signal transduction, transcription, cell cycle progress, protein degradation, apoptosis, and genetic stability through direct and indirect interaction with host factors. The subcellular localization of HBx is primarily cytoplasmic, with a small fraction in the nucleus. In addition, high levels of HBx expression lead to an abnormal mitochondrial distribution. The dynamic distribution of HBx could be important to the multiple functions of HBx at different stages of the HBV life cycle. This short review presents an overview of the differential roles of HBx as a function of its intracellular localization.
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Affiliation(s)
- Jingwei Ma
- Department of Immunology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
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Kim HJ, Kim JC, Min JS, Kim MJ, Kim JA, Kor MH, Yoo HS, Ahn JK. Aqueous extract of Tribulus terrestris Linn induces cell growth arrest and apoptosis by down-regulating NF-κB signaling in liver cancer cells. JOURNAL OF ETHNOPHARMACOLOGY 2011; 136:197-203. [PMID: 21549825 DOI: 10.1016/j.jep.2011.04.060] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 03/31/2011] [Accepted: 04/21/2011] [Indexed: 05/30/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE A medicinal herb Tribulus terrestris Linn has been used to treat various diseases including hepatocellular carcinoma. The aim of the present study was to investigate the anticancer activity of Tribulus terrestris Linn (TT) in liver cancer cells. MATERIALS AND METHODS The antitumor activity of aqueous TT extract was analyzed by testing the cytotoxicity and the effect on clonogenecity in HepG2 cells. Apoptosis and cell cycle arrest induced by TT were dissected by flow cytometry and its inhibitory effect on NF-κB activity was determined by analyzing the expression levels of NF-κB/IκB subunit proteins. The suppression of NF-κB-regulated gene expression by TT was assessed by RT-PCR. RESULTS TT extract repressed clonogenecity and proliferation, induced apoptosis, and enhanced accumulation in the G0/G1 phase of liver cancer cells. It also turned out that TT extract inhibited NF-κB-dependent reporter gene expression and NF-κB subunit p50 expression, while it enhanced the cellular level of IκBα by inhibiting the phosphorylation and degradation of IκBα. In addition, IKK activity was inhibited in a dose-dependent manner. Furthermore, TT extract suppressed the transcription of genes associated with cell cycle regulation, anti-apoptosis, and invasion. CONCLUSION These data showed that TT extract blocks proliferation and induces apoptosis in human liver cancer cells through the inhibition of NF-κB signaling. Aqueous TT extract can be used as an anticancer drug for hepatocellular carcinoma patients.
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Affiliation(s)
- Hye Jin Kim
- Department of Microbiology, Chungnam National University, Daejeon 305-764, South Korea
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Wu HY, Chang CI, Lin BW, Yu FL, Lin PY, Hsu JL, Yen CH, Liao MH, Shih WL. Suppression of hepatitis B virus x protein-mediated tumorigenic effects by ursolic Acid. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:1713-22. [PMID: 21314126 DOI: 10.1021/jf1045624] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This study investigated the potential effects of natural products ursolic acid (UA) and oleanolic acid (OA) against HBx-mediated tumorigenic activities in vitro and in vivo. HBx transactivated Sp-1 and Smad 3/4 in Huh7 and FL83B hepatocytes and induced cell migration of Huh7 and HepG2. HBx also induced MMP-3 secretion in Huh7 and acted against TGF-β-induced apoptosis in Hep3B. UA almost completely blocked the HBx-mediated effects, while OA had a partial inhibitive effect. Utilization of specific MAPK inhibitors and immunoblotting demonstrated that UA selectively activated MAPK signaling in certain tested cells. Preintraperitoneal injection of UA fully prevented the tumor growth of HBV-containing 2.2.15 cells, while OA-treated mice had smaller tumors than the control group. Our results suggested that UA possesses a hepatoprotective ability and illustrated the evident effects against HBx-mediated tumorigenic activities without toxicity in a mouse model.
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Affiliation(s)
- Hong-Yin Wu
- Graduate Institute of Biotechnology, National Pingtung University of Science and Technology, 1, Shuefu Rd., Neipu, Pingtung, 91201, Taiwan
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19
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Zhao R, Wang TZ, Kong D, Zhang L, Meng HX, Jiang Y, Wu YQ, Yu ZX, Jin XM. Hepatoma cell line HepG2.2.15 demonstrates distinct biological features compared with parental HepG2. World J Gastroenterol 2011; 17:1152-9. [PMID: 21448419 PMCID: PMC3063907 DOI: 10.3748/wjg.v17.i9.1152] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 11/29/2010] [Accepted: 12/06/2010] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the biological features of hepatitis B virus (HBV)-transfected HepG2.2.15 cells.
METHODS: The cell ultrastructure, cell cycle and apoptosis, and the abilities of proliferation and invasion of HBV-transfected HepG2.2.15 and the parent HepG2 cells were examined by electron microscopy, flow cytometry, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and trans-well assay. Oncogenicity of the two cell lines was compared via subcutaneous injection and orthotopic injection or implantation in nude mice, and the pathological analysis of tumor formation was performed. Two cytoskeletal proteins were detected by Western blotting.
RESULTS: Compared with HepG2 cells, HepG2.2.15 cells showed organelle degeneration and filopodia disappearance under electron microscope. HepG2.2.15 cells proliferated and migrated slowly in vitro, and hardly formed tumor and lung metastasis in nude mice. Flow cytometry showed that the majority of HepG2.2.15 cells were arrested in G1 phase, and apoptosis was minor in both cell lines. Furthermore, the levels of cytoskeletal proteins F-actin and Ezrin were decreased in HepG2.2.15 cells.
CONCLUSION: HepG2.2.15 cells demonstrated a lower proliferation and invasion ability than the HepG2 cells due to HBV transfection.
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Lee MJ, Jin YH, Kim K, Choi Y, Kim HC, Park S. Expression of hepatitis B virus x protein in hepatocytes suppresses CD8 T cell activity. Immune Netw 2010; 10:126-34. [PMID: 20844737 PMCID: PMC2939357 DOI: 10.4110/in.2010.10.4.126] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 07/20/2010] [Accepted: 07/23/2010] [Indexed: 01/07/2023] Open
Abstract
Background CD8+ T cells contribute to the clearance of Hepatitis B virus (HBV) infection and an insufficient CD8+ T cell response may be one of the major factors leading to chronic HBV infection. Since the HBx antigen of HBV can up-regulate cellular expression of several immunomodulatory molecules, we hypothesized that HBx expression in hepatocytes might affect CD8+ T cell activity. Methods We analyzed the activation and apoptosis of CD8+ T cells co-cultured with primary hepatocytes rendered capable of expressing HBx by recombinant baculovirus infection. Results Expression of HBx in hepatocytes induced low production of interferon-γ and apoptosis of CD8+ T cells, with no effect on CD8 T cell proliferation. However, transcriptional levels of H-2K, ICAM-1 and PD-1 ligand did not correlate with HBx expression in hepatocytes. Conclusion Our results suggest that HBx may inhibit CD8+ T cell response by regulation of interferon-γ production and apoptosis.
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Affiliation(s)
- Mi Jin Lee
- Department of Microbiology and Immunology, Ajou University School of Medicine, Suwon 442-721, Korea
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21
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Kim KH. [Pro-apoptotic function of hepatitis B virus X protein]. THE KOREAN JOURNAL OF HEPATOLOGY 2010; 16:112-22. [PMID: 20606495 DOI: 10.3350/kjhep.2010.16.2.112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Infection of hepatitis B virus (HBV) is a main cause of liver diseases including hepatitis, cirrhosis and hepatocellular carcinoma (HCC). Among the HBV-encoded proteins, the HBV X protein (HBx) has been suspected to be strongly involved in HBV-associated liver pathogenesis. HBx, a virally encoded multifunctional regulator, has been shown to induce apoptosis, anti-apoptosis, proliferation, and transformation of cells depending on the cell lines, model systems used, assay protocols, and research groups. Among the several activities of HBx, the pro-apoptotic function of HBx will be discussed in this review. Given that the disruption of apoptosis pathway by HBx contributes to the liver pathogenesis, a better understanding of the molecular interference in the cellular pro-apoptotic networks by HBx will provide useful clues for the intervention in HBV-mediated liver diseases.
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Affiliation(s)
- Kyun-Hwan Kim
- Department of Pharmacology, School of Medicine and Center for Cancer Research and Diagnostic Medicine, IBST, Konkuk University, Seoul, Korea.
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Kuo TC, Chao CCK. Hepatitis B virus X protein prevents apoptosis of hepatocellular carcinoma cells by upregulating SATB1 and HURP expression. Biochem Pharmacol 2010; 80:1093-102. [PMID: 20541537 DOI: 10.1016/j.bcp.2010.06.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 05/28/2010] [Accepted: 06/03/2010] [Indexed: 02/06/2023]
Abstract
Protein X from hepatitis B virus (HBV) appears to play a critical role in the development of hepatocellular carcinoma (HCC). The hepatoma upregulated protein (HURP) is also upregulated in a majority of HCC cases, therefore suggesting that HURP represents an oncogene. In this study, we describe a link between the viral protein HBx, HURP, and the establishment of cisplatin chemoresistance in HCC cells. Hep3B cells which express HBx displayed increased levels of HURP mRNA and protein, and showed resistance to cisplatin-induced apoptosis. Knockdown of HURP in HBx-expressing cells reversed this effect and sensitized Hep3B cells to cisplatin. Interestingly, SATB1, a global gene regulator which is often overexpressed in malignant breast cancer, was also induced following expression of HBx. The anti-apoptotic effect of HBx was shown to require activation of the p38/MAPK pathway in Hep3B cells. In addition, the expression of survivin, an anti-apoptotic protein, was also upregulated by HBx in an HURP-dependent manner. Taken together, these results indicate that HBx activates the expression of HURP via the p38/MAPK pathway and the SATB1 protein, culminating with the accumulation of the anti-apoptotic protein survivin. Our findings illustrate the role of the viral protein HBx in preventing apoptosis during cancer progression and establishment of chemoresistance.
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Affiliation(s)
- Tzu-Ching Kuo
- Department of Biochemistry and Molecular Biology, Graduate Institute of Biomedical Sciences, Chang Gung University, Gueishan, Taoyuan 333, Taiwan, ROC
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Kim HJ, Yoo HS, Kim JC, Park CS, Choi MS, Kim M, Choi H, Min JS, Kim YS, Yoon SW, Ahn JK. Antiviral effect of Curcuma longa Linn extract against hepatitis B virus replication. JOURNAL OF ETHNOPHARMACOLOGY 2009; 124:189-196. [PMID: 19409970 DOI: 10.1016/j.jep.2009.04.046] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 03/19/2009] [Accepted: 04/20/2009] [Indexed: 05/27/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE A medicinal herb Curcuma longa Linn has been used for treating various liver diseases caused by hepatitis B virus (HBV) in Asia. AIM OF THE STUDY The study was performed in order to investigate the antiviral activity of Curcuma longa Linn against HBV replication in liver cells. MATERIALS AND METHODS Aqueous extract of Curcuma longa Linn (CLL) was prepared and used to analyze its antiviral activity against HBV replication in HepG 2.2.15 cells, which contain HBV genomes. The inhibitory effect of CLL on HBV replication was examined by testing the levels of secreted HBV surface antigens (HBsAg), HBV DNAs, and HBV RNAs in HepG 2.2.15 cells using ELISA, Southern blot, and Northern blot analyses. Cytotoxic activities of CLL extract on various liver cells were analyzed by MTT assay. To dissect the inhibitory mechanism of CLL extract on HBV replication, the levels of p53 protein and p53 mRNAs were analyzed by Western blot and RT-PCR in HepG 2.2.15 cells. The repression of CLL extract on HBV transcription was analyzed by RT-PCR and CAT assay. RESULTS CLL extract repressed the secretion of HBsAg from HepG 2.2.15 cells. CLL extract also suppressed the production of HBV particles and the level of intracellular HBV RNAs in HepG 2.2.15 cells, suggesting that CLL extract inhibits HBV replication. We found that the anti-HBV activity of CLL extract is mediated through enhancing the cellular accumulation of p53 protein by transactivating the transcription of p53 gene as well as increasing the stability of p53 protein. It turned out that CLL extract repressed the transcription of HBx gene by suppressing HBV enhancer I and X promoter through p53 protein. In addition, CLL extract did not have any cytotoxic effects on liver cells. CONCLUSION These data showed that CLL extract represses HBV replication through enhancing the level of p53 protein. CLL extract can be used as a safe and specific drug for patients with liver diseases caused by HBV infection.
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Affiliation(s)
- Hye Jin Kim
- Department of Microbiology, Chungnam National University, Daejeon 305-764, South Korea
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24
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Kim HJ, Kim SY, Kim J, Lee H, Choi M, Kim JK, Ahn JK. Hepatitis B virus X protein induces apoptosis by enhancing translocation of Bax to mitochondria. IUBMB Life 2008; 60:473-80. [PMID: 18481805 DOI: 10.1002/iub.68] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Hepatitis B virus X protein (HBx) is essential for viral replication and plays an important role in viral pathogenesis. HBx transactivates many viral and cellular genes and participates in cellular signal transduction pathways, proliferation, and apoptosis. In the present study, we report that HBx induces apoptosis by enhancing the translocation of Bax to mitochondria, followed by inducing the loss of mitochondrial membrane potential and release of cytochrome C. In addition, Bcl-2, inhibitor of Bax, rescues the disruption of mitochondrial membrane potential and DNA fragmentation induced by serum starvation in HepG2-X cells expressing HBx. We also found that HBx binds directly to Bax and interferes with the interaction between Bax and 14-3-3epsilon to enhance the translocation of Bax to mitochondria. Taken together, our data suggest that HBx induces apoptosis by interacting with Bax and enhancing its translocation to mitochondria.
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Affiliation(s)
- Hye Jin Kim
- Department of Microbiology, School of Bioscience and Biotechnology, Chungnam National University, Daejeon 305-764, Korea
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25
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Kim SY, Kim JC, Kim JK, Kim HJ, Lee HM, Choi MS, Maeng PJ, Ahn JK. Hepatitis B virus X protein enhances NFκB activity through cooperating with VBP1. BMB Rep 2008; 41:158-63. [DOI: 10.5483/bmbrep.2008.41.2.158] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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26
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Wen Y, Golubkov VS, Strongin AY, Jiang W, Reed JC. Interaction of hepatitis B viral oncoprotein with cellular target HBXIP dysregulates centrosome dynamics and mitotic spindle formation. J Biol Chem 2007; 283:2793-803. [PMID: 18032378 DOI: 10.1074/jbc.m708419200] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Hepatitis B virus infection is associated with hepatocellular carcinoma, claiming 1 million lives annually worldwide. To understand the carcinogenic mechanism of hepatitis B virus-encoded oncoprotein HBx, we explored the function of HBx interaction with its cellular target HBXIP. Previously, we demonstrated that viral HBx and cellular HBXIP control mitotic spindle formation, regulating centrosome splitting. By using various fragments of HBx, we determined that residues (137)CRHK(140) within HBx are necessary for binding HBXIP. Mutation of the (137)CRHK(140) motif in HBx abolished its ability to bind HBXIP and to dysregulate centrosome dynamics in HeLa and immortal diploid RPE-1 cells. Unlike wild-type HBx, which targets to centrosomes as determined by subcellular fractionation and immunofluorescence microscopy, HBx mutants failed to localize to centrosomes. Overexpression of viral HBx wild-type protein and knockdown of endogenous HBXIP altered centrosome assembly and induced modifications of pericentrin and centrin-2, two essential proteins required for centrosome formation and function, whereas HBXIP nonbinding mutants of HBx did not. Overexpression of HBXIP or fragments of HBXIP that bind HBx neutralized the effects of viral HBx on centrosome dynamics and spindle formation. These results suggest that HBXIP is a critical target of viral HBx for promoting genetic instability through formation of defective spindles and subsequent aberrant chromosome segregation.
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Affiliation(s)
- Yunfei Wen
- Program on Apoptosis and Cell Death Research, Burnham Institute for Medical Research, 10901 N. Torrey Pines Road, La Jolla, CA 92037, USA
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Abstract
Chronic ethanol consumption is associated with serious and potentially fatal alcohol-related liver injuries such as hepatomegaly, alcoholic hepatitis and cirrhosis. Moreover, it has been documented that the clinical progression of alcohol-induced liver damage may be associated with an increase in hepatocellular death that involves apoptotic mechanisms. Although much information has been learned about the clinical manifestations associated with alcohol-related diseases, the search continues for a better understanding of the molecular and/or cellular mechanisms by which ethanol exerts its deleterious effects such as the induction of pro-apoptotic mechanisms and related cell damaging events. As part of the effort to enhance our understanding of those particular cellular pathways and mechanisms associated with ethanol toxicity, researchers over the years have utilized a variety of model systems. Recently, work has come forth demonstrating the utility of a hybrid cell line (WIF-B) as a cell culture model system for the study of alcohol-associated alterations in hepatocellular mechanisms. Success with such emerging model systems could aid in the development of potential therapeutic treatments for the prevention of alcohol-induced apoptotic cell death that may ultimately serve as a significant target in delaying the onset and/or progression of clinical symptoms of alcohol-mediated liver disease. This review article summarizes the current understanding of ethanol-mediated modifications in cell survival and thus the promotion of pro-apoptotic events with emphasis on analyses made in various experimental model systems, particularly the more recently characterized WIF-B cell system.
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Affiliation(s)
- Benita L McVicker
- Veterans Affairs Medical Center, Research Service (151), 4101 Woolworth Avenue, Omaha, NE 68105, USA.
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28
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Lu YW, Chen WN. Human hepatitis B virus X protein induces apoptosis in HepG2 cells: Role of BH3 domain. Biochem Biophys Res Commun 2005; 338:1551-6. [PMID: 16274670 DOI: 10.1016/j.bbrc.2005.10.117] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2005] [Accepted: 10/19/2005] [Indexed: 11/25/2022]
Abstract
The smallest protein of hepatitis B virus, HBX, has been implicated in the development of liver diseases by interfering with normal cellular processes. Its role in cell proliferation has been unclear as both pro-apoptotic and anti-apoptotic activities have been reported. We showed molecular evidence that HBX induced apoptosis in HepG2 cells. A Bcl-2 Homology Domain 3 was identified in HBX, which interacted with anti-apoptotic but not pro-apoptotic members of the Bcl-2 family of proteins. HBX induced apoptosis when transfected into HepG2 cells, as demonstrated by both flow cytometry and caspase-3 activity. However, HBX protein may not be stable in apoptotic cells triggered by its own expression as only its mRNA or the fusion protein with the glutathione-S-transferase was detected in transfected cells. Our results suggested that HBX behaved as a pro-apoptotic protein and was able to induce apoptosis.
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Affiliation(s)
- Yi Wei Lu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive 05N-10, Singapore 637551, Singapore
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