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Li D, Hamadalnil Y, Tu T. Hepatitis B Viral Protein HBx: Roles in Viral Replication and Hepatocarcinogenesis. Viruses 2024; 16:1361. [PMID: 39339838 PMCID: PMC11437454 DOI: 10.3390/v16091361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2024] [Revised: 08/20/2024] [Accepted: 08/21/2024] [Indexed: 09/30/2024] Open
Abstract
Hepatitis B virus (HBV) infection remains a major public health concern worldwide, with approximately 296 million individuals chronically infected. The HBV-encoded X protein (HBx) is a regulatory protein of 17 kDa, reportedly responsible for a broad range of functions, including viral replication and oncogenic processes. In this review, we summarize the state of knowledge on the mechanisms underlying HBx functions in viral replication, the antiviral effect of therapeutics directed against HBx, and the role of HBx in liver cancer development (including a hypothetical model of hepatocarcinogenesis). We conclude by highlighting major unanswered questions in the field and the implications of their answers.
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Affiliation(s)
- Dong Li
- The Westmead Institute for Medical Research, Faculty of Medicine, The University of Sydney, Westmead, NSW 2145, Australia;
| | | | - Thomas Tu
- The Westmead Institute for Medical Research, Faculty of Medicine, The University of Sydney, Westmead, NSW 2145, Australia;
- Centre for Infectious Diseases and Microbiology, Sydney Infectious Diseases Institute, The University of Sydney at Westmead Hospital, Westmead, NSW 2145, Australia
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Zhang M, Chen H, Liu H, Tang H. The impact of integrated hepatitis B virus DNA on oncogenesis and antiviral therapy. Biomark Res 2024; 12:84. [PMID: 39148134 PMCID: PMC11328401 DOI: 10.1186/s40364-024-00611-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Accepted: 06/29/2024] [Indexed: 08/17/2024] Open
Abstract
The global burden of hepatitis B virus (HBV) infection remains high, with chronic hepatitis B (CHB) patients facing a significantly increased risk of developing cirrhosis and hepatocellular carcinoma (HCC). The ultimate objective of antiviral therapy is to achieve a sterilizing cure for HBV. This necessitates the elimination of intrahepatic covalently closed circular DNA (cccDNA) and the complete eradication of integrated HBV DNA. This review aims to summarize the oncogenetic role of HBV integration and the significance of clearing HBV integration in sterilizing cure. It specifically focuses on the molecular mechanisms through which HBV integration leads to HCC, including modulation of the expression of proto-oncogenes and tumor suppressor genes, induction of chromosomal instability, and expression of truncated mutant HBV proteins. The review also highlights the impact of antiviral therapy in reducing HBV integration and preventing HBV-related HCC. Additionally, the review offers insights into future objectives for the treatment of CHB. Current strategies for HBV DNA integration inhibition and elimination include mainly antiviral therapies, RNA interference and gene editing technologies. Overall, HBV integration deserves further investigation and can potentially serve as a biomarker for CHB and HBV-related HCC.
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Affiliation(s)
- Mingming Zhang
- Center of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, 610041, China
- Laboratory of Infectious and Liver Diseases, Institute of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Han Chen
- Center of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, 610041, China
- Laboratory of Infectious and Liver Diseases, Institute of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Huan Liu
- Center of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, 610041, China
- Laboratory of Infectious and Liver Diseases, Institute of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Hong Tang
- Center of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, 610041, China.
- Laboratory of Infectious and Liver Diseases, Institute of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, 610041, China.
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Kusunoki H, Sakamoto T, Kobayashi N, Kohno T, Wakamatsu K, Nagata T. Structural Insights into the Interaction between the C-Terminal-Deleted BH3-like Motif Peptide of Hepatitis B Virus X Protein and Bcl-x L. Biochemistry 2024; 63:632-643. [PMID: 38377677 DOI: 10.1021/acs.biochem.3c00709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Hepatitis B virus X protein (HBx) plays a crucial role in the development of hepatocellular carcinoma (HCC) associated with hepatitis B virus (HBV) infection. The full-length HBx protein interacts with Bcl-xL and is involved in the HBV replication and cell death processes. The three hydrophobic residues Trp120, Leu123, and Ile127 of the HBx BH3-like motif are essential for the Bcl-xL-binding. On the other hand, various lengths of C-terminal-truncated HBx mutants are frequently detected in HCC tissues, and these mutants, rather than the full-length HBx, appear to be responsible for HCC development. Notably, the region spanning residues 1-120 of HBx [HBx(1 and 120)] has been strongly associated with an increased risk of HCC development. However, the mode of interaction between HBx(1-120) and Bcl-xL remains unclear. HBx(1-120) possesses only Trp120 among the three hydrophobic residues essential for the Bcl-xL-binding. To elucidate this interaction mode, we employed a C-terminal-deleted HBx BH3-like motif peptide composed of residues 101-120. Here, we present the NMR complex structure of Bcl-xL and HBx(101-120). Our results demonstrate that HBx(101-120) binds to Bcl-xL in a weaker manner. Considering the high expression of Bcl-xL in HCC cells, this weak interaction, in conjunction with the overexpression of Bcl-xL in HCC cells, may potentially contribute to HCC development through the interaction between C-terminal-truncated HBx and Bcl-xL.
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Affiliation(s)
- Hideki Kusunoki
- Research Center for Biological Products in the Next Generation, National Institute of Infectious Diseases, Musashimurayama, Tokyo 208-0011, Japan
| | - Taiichi Sakamoto
- Department of Life Science, Faculty of Advanced Engineering, Chiba Institute of Technology, Narashino, Chiba 275-0016, Japan
| | - Naohiro Kobayashi
- Laboratory for Advanced NMR Application and Development, RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan
| | - Toshiyuki Kohno
- Department of Medical Informatics, Research and Development Center for Medical Education, Kitasato University School of Medicine, Sagamihara, Kanagawa 252-0374, Japan
| | - Kaori Wakamatsu
- Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Takashi Nagata
- Institute of Advanced Energy, Kyoto University, Kyoto, Uji 611-0011, Japan
- Graduate School of Energy Science, Kyoto University, Kyoto, Uji 611-0011, Japan
- Integrated Research Center for Carbon Negative Science, Kyoto University, Kyoto, Uji 611-0011, Japan
- Biomass Product Tree Industry-Academia Collaborative Research Laboratory, Kyoto University, Kyoto, Uji 611-0011, Japan
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Xu P. Nuclear Receptors in Health and Diseases. Int J Mol Sci 2023; 24:9153. [PMID: 37298107 PMCID: PMC10252477 DOI: 10.3390/ijms24119153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 05/11/2023] [Accepted: 05/18/2023] [Indexed: 06/12/2023] Open
Abstract
Nuclear receptors (NRs) are a vital superfamily of transcription factors that play crucial roles in physiology and pharmacology [...].
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Affiliation(s)
- Pengfei Xu
- Department of Hepatobiliary and Pancreatic Surgery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China;
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261, USA
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