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Yang Y, Liu M, Han J, Wu H, Zhao C, Lyu X, Hu X, Liu Y, Xu D, Xie W, Huang J, Wu S, Li J, Lei J, Zhang Y, Zhang H, He Y, Peng Z, Wang Y, Shen H, Wang Q, Zhang Y, Yan D, Wang L, He Y, Ma X. Paternal Preconception Hepatitis B Virus Infection and Risk of Congenital Heart Disease in Offspring. JAMA Pediatr 2024; 178:1041-1048. [PMID: 39158862 PMCID: PMC11334012 DOI: 10.1001/jamapediatrics.2024.2680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 06/03/2024] [Indexed: 08/20/2024]
Abstract
Importance Previous evidence suggests that maternal hepatitis B virus (HBV) infection during prepregnancy or pregnancy is associated with congenital heart diseases (CHDs) in offspring. However, the association of paternal HBV infection with CHDs is not well examined. Objective To explore the association of paternal preconception HBV infection with CHDs in offspring. Design, Setting, and Participants This retrospective cohort study used propensity score matching of data from the Chinese National Free Preconception Checkup Project (NFPCP) from January 1, 2010, to December 31, 2018. Male participants whose wives were aged 20 to 49 years, were uninfected with HBV, and successfully conceived within 1 year after prepregnancy examination were enrolled. Data were analyzed from March 2023 to February 2024. Exposures The primary exposure was paternal preconception HBV infection status, including uninfected, previous infection (both serum hepatitis B surface antigen and hepatitis B envelope antigen negative), and new infection (serum hepatitis B surface antigen positive). Maternal HBV immune status was further classified as immune or susceptible. Main Outcomes and Measures The main outcome was CHDs, which were collected from the birth defect registration card of the NFPCP. Logistic regression with robust error variances was used to estimate the association between paternal preconception HBV infection and CHDs in offspring. Results A total of 6 675 540 couples participated in the NFPCP service. After matching husbands with and without preconception HBV infection in a 1:4 ratio, 3 047 924 couples (median age of husbands, 27 years [IQR, 25-30 years]) were included in this study. Of these couples, 0.025% had offspring with CHDs. Previous paternal HBV infection was independently associated with CHDs in offspring (adjusted relative risk [ARR], 1.40; 95% CI, 1.11-1.76) compared with no infection. Similar results were obtained in subgroup analyses according to maternal HBV immune status. Compared with couples with uninfected husbands and susceptible wives, the risk of CHDs in offspring among couples with previously HBV-infected husbands was similar in couples with wives with susceptible immune status (ARR, 1.49; 95% CI, 1.10-2.03) and in those with wives with immunity (ARR, 1.49; 95%CI, 1.07-2.09). A significantly higher CHD risk in offspring was found among couples with newly infected husbands and immune wives (ARR, 1.38; 95% CI, 1.05-1.82), but there was no difference in risk among those with newly infected husbands and susceptible wives (ARR, 0.99; 95% CI, 0.72-1.36). No interactions were found between maternal immune status and paternal HBV infection. Conclusions and Relevance In this cohort study using propensity score matching, previous paternal preconception HBV infection was associated with CHD risk in offspring. The findings suggest that personalized reproductive guidance regarding HBV screening and staying free of HBV infection should be provided for both wives and husbands.
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Affiliation(s)
- Ying Yang
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
- Graduate School of Peking Union Medical College, Beijing, China
| | - Meiya Liu
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
- Institute of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, China
| | - Jiancheng Han
- Maternal-Fetal Medicine Center in Fetal Heart Disease, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Hanbin Wu
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
| | - Chuanyu Zhao
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
- Graduate School of Peking Union Medical College, Beijing, China
| | - Xinyi Lyu
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
- Graduate School of Peking Union Medical College, Beijing, China
| | - Xuan Hu
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
| | - Youhong Liu
- Institute of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, China
| | - Die Xu
- Institute of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, China
| | - Wenlu Xie
- Institute of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, China
| | - Jiaxin Huang
- Institute of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, China
| | - Siyu Wu
- Institute of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, China
| | - Jiaxin Li
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
- Graduate School of Peking Union Medical College, Beijing, China
| | - Jueming Lei
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
| | - Ya Zhang
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
| | - Hongguang Zhang
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
| | - Yuan He
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
- Graduate School of Peking Union Medical College, Beijing, China
| | - Zuoqi Peng
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
| | - Yuanyuan Wang
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
- Graduate School of Peking Union Medical College, Beijing, China
| | - Haiping Shen
- Department of Maternal and Child Health, National Health Commission of the PRC, Beijing, China
| | - Qiaomei Wang
- Department of Maternal and Child Health, National Health Commission of the PRC, Beijing, China
| | - Yiping Zhang
- Department of Maternal and Child Health, National Health Commission of the PRC, Beijing, China
| | - Donghai Yan
- Department of Maternal and Child Health, National Health Commission of the PRC, Beijing, China
| | - Long Wang
- Institute of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, China
| | - Yihua He
- Maternal-Fetal Medicine Center in Fetal Heart Disease, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Xu Ma
- National Research Institute for Family Planning, Beijing, China
- National Human Genetic Resources Centre, Beijing, China
- Graduate School of Peking Union Medical College, Beijing, China
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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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3
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Yang Z, Zeng J, Chen Y, Wang M, Luo H, Huang AL, Deng H, Hu Y. Detection of HBV DNA integration in plasma cell-free DNA of different HBV diseases utilizing DNA capture strategy. Virol Sin 2024; 39:655-666. [PMID: 38852920 PMCID: PMC11401475 DOI: 10.1016/j.virs.2024.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 06/04/2024] [Indexed: 06/11/2024] Open
Abstract
The landscape of hepatitis B virus (HBV) integration in the plasma cell-free DNA (cfDNA) of HBV-infected patients with different stages of liver diseases [chronic hepatitis B (CHB), liver cirrhosis (LC), and hepatocellular carcinoma (HCC)] remains unclear. In this study, we developed an improved strategy for detecting HBV DNA integration in plasma cfDNA, based on DNA probe capture and next-generation sequencing. Using this optimized strategy, we successfully detected HBV integration events in chimeric artificial DNA samples and HBV-infected HepG2-NTCP cells at day one post infection, with high sensitivity and accuracy. The characteristics of HBV integration events in the HBV-infected HepG2-NTCP cells and plasma cfDNA from HBV-infected individuals (CHB, LC, and HCC) were further investigated. A total of 112 and 333 integration breakpoints were detected in the HepG2-NTCP cells and 22 out of 25 (88%) clinical HBV-infected samples, respectively. In vivo analysis showed that the normalized number of support unique sequences (nnsus) in HCC was significantly higher than in CHB or LC patients (P values < 0.05). All integration breakpoints are randomly distributed on human chromosomes and are enriched in the HBV genome around nt 1800. The majority of integration breakpoints (61.86%) are located in the gene-coding region. Both non-homologous end-joining (NHEJ) and microhomology-mediated end-joining (MMEJ) interactions occurred during HBV integration across the three different stages of liver diseases. Our study provides evidence that HBV DNA integration can be detected in the plasma cfDNA of HBV-infected patients, including those with CHB, LC, or HCC, using this optimized strategy.
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Affiliation(s)
- Zerui Yang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, 400016, China
| | - Jingyan Zeng
- Department of Infectious Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Yueyue Chen
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, 400016, China
| | - Mengchun Wang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, 400016, China
| | - Hongchun Luo
- Department of Infectious Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Ai-Long Huang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, 400016, China.
| | - Haijun Deng
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, 400016, China.
| | - Yuan Hu
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, 400016, China.
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4
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Gan W, Gao N, Gu L, Mo Z, Pang X, Lei Z, Gao Z. Reduction in Intrahepatic cccDNA and Integration of HBV in Chronic Hepatitis B Patients with a Functional Cure. J Clin Transl Hepatol 2023; 11:314-322. [PMID: 36643049 PMCID: PMC9817062 DOI: 10.14218/jcth.2022.00177] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/11/2022] [Accepted: 06/12/2022] [Indexed: 01/18/2023] Open
Abstract
Background and Aims Functional cure (FC) is characterized by the clearance of the hepatitis B surface antigen from the serum of patients with chronic hepatitis B (CHB). However, the level of intrahepatic covalently closed circular DNA (cccDNA) and hepatitis B virus (HBV) integration remains unclear. We conducted this study to determine them and reveal their value in the treatment of CHB. Methods There were two sessions to elucidate the changes in intrahepatic cccDNA and HBV integration after antiviral therapy. In the first session, 116 patients were enrolled and divided into FC, non-functional cure (NFC), and CHB groups, including 48 patients with functionally cured CHB, 27 with CHB without functional cure after antiviral treatment, and 41 with treatment-naïve CHB. Patients were tested for both intrahepatic cccDNA and other viral markers. All patients in the FC group were followed up for at least 24 weeks to observe relapse. In the second session, another ten patients were included for in-depth whole-genome sequencing to analyze HBV integration. Results Thirteen patients in the FC group were negative for intrahepatic cccDNA. Intrahepatic cccDNA was much higher in the CHB group compared with the FC group. Seven patients had HBsAg seroreversion, including two with virological relapse. Integration of HBV was detected in one (33.3%) functionally cured patients and in seven (100%) with CHB. 28.0% of the HBV breakpoints were assigned in the 1,500 nt to 1,900 nt range of the HBV genome. Conclusions After achieving an FC, the rate of intrahepatic cccDNA and HBV integration was significantly reduced in patients with CHB. For those patients who cleared intrahepatic cccDNA, the chances of developing virological relapse were even lower.
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Affiliation(s)
- Weiqiang Gan
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Na Gao
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Lin Gu
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zhishuo Mo
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Xiuqing Pang
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Ziying Lei
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zhiliang Gao
- Department of Infectious Diseases, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
- Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, Guangdong, China
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5
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Shi XJ, Yao CG, Li HL, Wei YH, Hu KH. Chromosome hyperploidy induced by chronic hepatitis B virus infection and its targeted therapeutic strategy. Shijie Huaren Xiaohua Zazhi 2023; 31:299-306. [DOI: 10.11569/wcjd.v31.i8.299] [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: 04/28/2023] Open
Abstract
Chronic hepatitis B virus (HBV) infection induces chromosomal hyperploidy (including aneuploidy and polyploidy) and chromosomal instability in hepatocytes, which is one of the main causes of primary hepatocellular carcinoma (HCC). Although hepatocytes can regulate polyploidization of chromosomes under normal conditions, it is difficult to regulate hyperploidization caused by HBV infection and thus carcinogenesis. Studies have shown that HBV can cause dysregulation of many signal pathways such as PLK1/PRC1, and induce chromosome hyperploidy and malignant transformation of hepatocytes. Herein we review the mechanism of HBV infection-induced chromosomal hyperploidy of hepatocytes to cuase hepatocarcinogenesis and the advances in research of drugs targeting chromosomal hyperploidy.
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6
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Svicher V, Salpini R, Piermatteo L, Carioti L, Battisti A, Colagrossi L, Scutari R, Surdo M, Cacciafesta V, Nuccitelli A, Hansi N, Ceccherini Silberstein F, Perno CF, Gill US, Kennedy PTF. Whole exome HBV DNA integration is independent of the intrahepatic HBV reservoir in HBeAg-negative chronic hepatitis B. Gut 2021; 70:2337-2348. [PMID: 33402415 PMCID: PMC8588301 DOI: 10.1136/gutjnl-2020-323300] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 11/02/2020] [Accepted: 11/16/2020] [Indexed: 12/17/2022]
Abstract
OBJECTIVE The involvement of HBV DNA integration in promoting hepatocarcinogenesis and the extent to which the intrahepatic HBV reservoir modulates liver disease progression remains poorly understood. We examined the intrahepatic HBV reservoir, the occurrence of HBV DNA integration and its impact on the hepatocyte transcriptome in hepatitis B 'e' antigen (HBeAg)-negative chronic hepatitis B (CHB). DESIGN Liver tissue from 84 HBeAg-negative patients with CHB with low (n=12), moderate (n=25) and high (n=47) serum HBV DNA was analysed. Covalently closed circular DNA (cccDNA), pregenomic RNA (pgRNA) were evaluated by quantitative PCR, whole exome and transcriptome sequencing was performed by Illumina, and the burden of HBV DNA integrations was evaluated by digital droplet PCR. RESULTS Patients with low and moderate serum HBV DNA displayed comparable intrahepatic cccDNA and pgRNA, significantly lower than in patients with high HBV DNA, while hepatitis B core-related antigen correlated strongly with the intrahepatic HBV reservoir, reflecting cccDNA quantity. Whole exome integration was detected in a significant number of patients (55.6%, 14.3% and 25% in high, moderate and low viraemic patients, respectively), at a frequency ranging from 0.5 to 157 integrations/1000 hepatocytes. Hepatitis B surface antigen >5000 IU/mL predicted integration within the exome and these integrations localised in genes involved in hepatocarcinogenesis, regulation of lipid/drug metabolism and antiviral/inflammatory responses. Transcript levels of specific genes, including the proto-oncogene hRAS, were higher in patients with HBV DNA integration, supporting an underlying oncogenic risk in patients with low-level to moderate-level viraemia. CONCLUSIONS HBV DNA integration occurs across all HBeAg-negative patients with CHB, including those with a limited HBV reservoir; localising in genes involved in carcinogenesis and altering the hepatocyte transcriptome.
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Affiliation(s)
- Valentina Svicher
- Department of Experimental Medicine, University of Rome Tor Vergata, Roma, Lazio, Italy
| | - Romina Salpini
- Department of Experimental Medicine, University of Rome Tor Vergata, Roma, Lazio, Italy
| | - Lorenzo Piermatteo
- Department of Experimental Medicine, University of Rome Tor Vergata, Roma, Lazio, Italy
| | - Luca Carioti
- Department of Experimental Medicine, University of Rome Tor Vergata, Roma, Lazio, Italy
| | - Arianna Battisti
- Department of Experimental Medicine, University of Rome Tor Vergata, Roma, Lazio, Italy,Barts Liver Cente, Immunobiology, Blizard Institute, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Luna Colagrossi
- Department of Experimental Medicine, University of Rome Tor Vergata, Roma, Lazio, Italy,Department of Microbiology and Virology, University of Milan, Milano, Lombardia, Italy
| | - Rossana Scutari
- Department of Experimental Medicine, University of Rome Tor Vergata, Roma, Lazio, Italy
| | - Matteo Surdo
- Molecular Genetics Laboratory, Eurofins GENOMA, Roma, Lazio, Italy
| | | | | | - Navjyot Hansi
- Barts Liver Cente, Immunobiology, Blizard Institute, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | | | - Carlo Federico Perno
- Department of Oncology and Haematooncology, University of Milan, Milano, Lombardia, Italy
| | - Upkar S Gill
- Barts Liver Cente, Immunobiology, Blizard Institute, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Patrick T F Kennedy
- Barts Liver Cente, Immunobiology, Blizard Institute, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
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7
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Bousali M, Papatheodoridis G, Paraskevis D, Karamitros T. Hepatitis B Virus DNA Integration, Chronic Infections and Hepatocellular Carcinoma. Microorganisms 2021; 9:1787. [PMID: 34442866 PMCID: PMC8398950 DOI: 10.3390/microorganisms9081787] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/13/2021] [Accepted: 08/18/2021] [Indexed: 12/16/2022] Open
Abstract
Hepatitis B Virus (HBV) is an Old World virus with a high mutation rate, which puts its origins in Africa alongside the origins of Homo sapiens, and is a member of the Hepadnaviridae family that is characterized by a unique viral replication cycle. It targets human hepatocytes and can lead to chronic HBV infection either after acute infection via horizontal transmission usually during infancy or childhood or via maternal-fetal transmission. HBV has been found in ~85% of HBV-related Hepatocellular Carcinomas (HCC), and it can integrate the whole or part of its genome into the host genomic DNA. The molecular mechanisms involved in the HBV DNA integration is not yet clear; thus, multiple models have been described with respect to either the relaxed-circular DNA (rcDNA) or the double-stranded linear DNA (dslDNA) of HBV. Various genes have been found to be affected by HBV DNA integration, including cell-proliferation-related genes, oncogenes and long non-coding RNA genes (lincRNAs). The present review summarizes the advances in the research of HBV DNA integration, focusing on the evolutionary and molecular side of the integration events along with the arising clinical aspects in the light of WHO's commitment to eliminate HBV and viral hepatitis by 2030.
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Affiliation(s)
- Maria Bousali
- Bioinformatics and Applied Genomics Unit, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece;
| | - George Papatheodoridis
- Department of Gastroenterology, “Laiko” General Hospital of Athens, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | - Dimitrios Paraskevis
- Department of Hygiene Epidemiology and Medical Statistics, School of Medicine, National and Kapodistrian University of Athens, 15772 Athens, Greece;
| | - Timokratis Karamitros
- Bioinformatics and Applied Genomics Unit, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece;
- Laboratory of Medical Microbiology, Department of Microbiology, Hellenic Pasteur Institute, 11521 Athens, Greece
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8
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He Z, Zhu J, Mo J, Zhao H, Chen Q. HBV DNA integrates into upregulated ZBTB20 in patients with hepatocellular carcinoma. Mol Med Rep 2020; 22:380-386. [PMID: 32319639 PMCID: PMC7248478 DOI: 10.3892/mmr.2020.11074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 03/18/2020] [Indexed: 12/27/2022] Open
Abstract
Hepatitis B virus (HBV) affects the malignant phenotype of hepatocellular carcinoma (HCC). The aim of the present study was to investigate the integration sites of HBV DNA and the expression of the zinc finger protein, zinc finger and BTB domain containing 20 (ZBTB20) in patients with hepatocellular carcinoma. Integration of the HBV gene was detected using a high-throughput sequencing technique based on the HBV-Alu-PCR method. The expression of ZBTB20 was detected by western blotting. HBVX integration sites were detected in ~70% of the HCC tissue samples. HBV-integrated subgene X detection suggested that 67% of the integrated specimens were inserted into the host X gene in a forward direction, 57% in a reverse direction, 24% in both forward and reverse directions, and 38% had two HBV integration sites. A total of 3,320 HBV integration sites were identified, including 1,397 in HCC tissues, 1,205 in paracancerous tissues and 718 in normal liver tissues. HBV integration fragments displayed enrichment in the 200–800 bp region. Additionally, the results suggested that HBV was highly integrated into transmembrane phosphatase with tensin homology, long intergenic non-protein coding RNA (LINC)00618, LOC101929241, ACTR3 pseudogene 5, LINC00999, LOC101928775, deleted in oesophageal cancer 1, LINC00824, EBF transcription factor 2 and ZBTB20 in tumour tissues. Furthermore, the expression of ZBTB20 was upregulated in HCC tissues compared with normal control liver tissues, and was associated with HBV integration frequency. The present study suggested that HBV DNA integrated into upregulated ZBTB20 in patients with hepatocellular carcinoma, which might promote the occurrence and development of HCC. Furthermore, the results of the present study may provide a theoretical basis for the diagnosis and treatment of HCC.
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Affiliation(s)
- Zebao He
- Department of Neurology, Taizhou Enze Medical Center Enze Hospital, Taizhou, Zhejiang 318000, P.R. China
| | - Jiansheng Zhu
- Department of Neurology, Taizhou Enze Medical Center Enze Hospital, Taizhou, Zhejiang 318000, P.R. China
| | - Jinggang Mo
- Department of Neurology, Taizhou Central Hospital, Taizhou University Hospital, Taizhou, Zhejiang 318000, P.R. China
| | - Haihong Zhao
- Department of Neurology, Taizhou Enze Medical Center Enze Hospital, Taizhou, Zhejiang 318000, P.R. China
| | - Qiuyue Chen
- Department of Neurology, Taizhou Central Hospital, Taizhou University Hospital, Taizhou, Zhejiang 318000, P.R. China
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9
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Zhao LH, Liu X, Yan HX, Li WY, Zeng X, Yang Y, Zhao J, Liu SP, Zhuang XH, Lin C, Qin CJ, Zhao Y, Pan ZY, Huang G, Liu H, Zhang J, Wang RY, Yang Y, Wen W, Lv GS, Zhang HL, Wu H, Huang S, Wang MD, Tang L, Cao HZ, Wang L, Lee TL, Jiang H, Tan YX, Yuan SX, Hou GJ, Tao QF, Xu QG, Zhang XQ, Wu MC, Xu X, Wang J, Yang HM, Zhou WP, Wang HY. Genomic and oncogenic preference of HBV integration in hepatocellular carcinoma. Nat Commun 2016; 7:12992. [PMID: 27703150 PMCID: PMC5059470 DOI: 10.1038/ncomms12992] [Citation(s) in RCA: 212] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 08/24/2016] [Indexed: 02/08/2023] Open
Abstract
Hepatitis B virus (HBV) can integrate into the human genome, contributing to genomic instability and hepatocarcinogenesis. Here by conducting high-throughput viral integration detection and RNA sequencing, we identify 4,225 HBV integration events in tumour and adjacent non-tumour samples from 426 patients with HCC. We show that HBV is prone to integrate into rare fragile sites and functional genomic regions including CpG islands. We observe a distinct pattern in the preferential sites of HBV integration between tumour and non-tumour tissues. HBV insertional sites are significantly enriched in the proximity of telomeres in tumours. Recurrent HBV target genes are identified with few that overlap. The overall HBV integration frequency is much higher in tumour genomes of males than in females, with a significant enrichment of integration into chromosome 17. Furthermore, a cirrhosis-dependent HBV integration pattern is observed, affecting distinct targeted genes. Our data suggest that HBV integration has a high potential to drive oncogenic transformation. Hepatitis B infection is a risk factor for hepatocellular carcinoma. Here, the authors characterise viral infection in a cohort of hepatocellular carcinoma patients and find viral integration is more frequent in males than females.
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Affiliation(s)
- Ling-Hao Zhao
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China.,National Center for Liver Cancer, Shanghai 200438, China
| | - Xiao Liu
- BGI-Shenzhen, Shenzhen 518083, China
| | - He-Xin Yan
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China.,National Center for Liver Cancer, Shanghai 200438, China
| | - Wei-Yang Li
- BGI-Shenzhen, Shenzhen 518083, China.,School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China
| | - Xi Zeng
- BGI-Shenzhen, Shenzhen 518083, China.,Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong 999077, China
| | - Yuan Yang
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Jie Zhao
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | | | | | - Chuan Lin
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Chen-Jie Qin
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China.,National Center for Liver Cancer, Shanghai 200438, China
| | - Yi Zhao
- School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China
| | - Ze-Ya Pan
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Gang Huang
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Hui Liu
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Jin Zhang
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Ruo-Yu Wang
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Yun Yang
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Wen Wen
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China.,National Center for Liver Cancer, Shanghai 200438, China
| | - Gui-Shuai Lv
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China.,National Center for Liver Cancer, Shanghai 200438, China
| | - Hui-Lu Zhang
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China.,National Center for Liver Cancer, Shanghai 200438, China
| | - Han Wu
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China.,National Center for Liver Cancer, Shanghai 200438, China
| | - Shuai Huang
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Ming-Da Wang
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China.,National Center for Liver Cancer, Shanghai 200438, China
| | - Liang Tang
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China.,National Center for Liver Cancer, Shanghai 200438, China
| | | | - Ling Wang
- Department of Vascular and Endocrine Surgery, Xijing Hospital, Fourth Military Medical University, Xi An 710032, China
| | - Tin-Lap Lee
- Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong 999077, China
| | - Hui Jiang
- BGI-Shenzhen, Shenzhen 518083, China
| | - Ye-Xiong Tan
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China.,National Center for Liver Cancer, Shanghai 200438, China
| | - Sheng-Xian Yuan
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Guo-Jun Hou
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Qi-Fei Tao
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Qin-Guo Xu
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | | | - Meng-Chao Wu
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Xun Xu
- BGI-Shenzhen, Shenzhen 518083, China
| | - Jun Wang
- BGI-Shenzhen, Shenzhen 518083, China.,Department of Biology, University of Copenhagen, Ole Maaløes Vej 5,2200 Copenhagen, Denmark
| | | | - Wei-Ping Zhou
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China
| | - Hong-Yang Wang
- Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, China.,National Center for Liver Cancer, Shanghai 200438, China.,State Key Laboratory of Oncogenes and Related Genes, Cancer Institute of Renji Hospital, Shanghai Jiaotong University, Shanghai 200127, China
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10
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Niller HH, Ay E, Banati F, Demcsák A, Takacs M, Minarovits J. Wild type HBx and truncated HBx: Pleiotropic regulators driving sequential genetic and epigenetic steps of hepatocarcinogenesis and progression of HBV-associated neoplasms. Rev Med Virol 2015; 26:57-73. [PMID: 26593760 DOI: 10.1002/rmv.1864] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 09/30/2015] [Accepted: 10/15/2015] [Indexed: 12/23/2022]
Abstract
Hepatitis B virus (HBV) is one of the causative agents of hepatocellular carcinoma. The molecular mechanisms of tumorigenesis are complex. One of the host factors involved is apparently the long-lasting inflammatory reaction which accompanies chronic HBV infection. Although HBV lacks a typical viral oncogene, the HBx gene encoding a pleiotropic regulatory protein emerged as a major player in liver carcinogenesis. Here we review the tumorigenic functions of HBx with an emphasis on wild type and truncated HBx variants, and their role in the transcriptional dysregulation and epigenetic reprogramming of the host cell genome. We suggest that HBx acquired by the HBV genome during evolution acts like a cellular proto-onc gene that is activated by deletion during hepatocarcinogenesis. The resulting viral oncogene (v-onc gene) codes for a truncated HBx protein that facilitates tumor progression. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Hans Helmut Niller
- Institute for Medical Microbiology and Hygiene, University of Regensburg, Regensburg, Germany
| | - Eva Ay
- Department of Retrovirology, National Center for Epidemiology, Budapest, Hungary
| | - Ferenc Banati
- RT-Europe Nonprofit Research Center, Mosonmagyarovar, Hungary
| | - Anett Demcsák
- University of Szeged, Faculty of Dentistry, Department of Oral Biology and Experimental Dental Research, Szeged, Hungary
| | - Maria Takacs
- Division of Virology, National Center for Epidemiology, Budapest, Hungary
| | - Janos Minarovits
- University of Szeged, Faculty of Dentistry, Department of Oral Biology and Experimental Dental Research, Szeged, Hungary
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11
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Zeisel MB, Lucifora J, Mason WS, Sureau C, Beck J, Levrero M, Kann M, Knolle PA, Benkirane M, Durantel D, Michel ML, Autran B, Cosset FL, Strick-Marchand H, Trépo C, Kao JH, Carrat F, Lacombe K, Schinazi RF, Barré-Sinoussi F, Delfraissy JF, Zoulim F. Towards an HBV cure: state-of-the-art and unresolved questions--report of the ANRS workshop on HBV cure. Gut 2015; 64:1314-26. [PMID: 25670809 DOI: 10.1136/gutjnl-2014-308943] [Citation(s) in RCA: 215] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 01/10/2015] [Indexed: 12/11/2022]
Abstract
HBV infection is a major cause of liver cirrhosis and hepatocellular carcinoma. Although HBV infection can be efficiently prevented by vaccination, and treatments are available, to date there is no reliable cure for the >240 million individuals that are chronically infected worldwide. Current treatments can only achieve viral suppression, and lifelong therapy is needed in the majority of infected persons. In the framework of the French National Agency for Research on AIDS and Viral Hepatitis 'HBV Cure' programme, a scientific workshop was held in Paris in June 2014 to define the state-of-the-art and unanswered questions regarding HBV pathobiology, and to develop a concerted strategy towards an HBV cure. This review summarises our current understanding of HBV host-interactions leading to viral persistence, as well as the roadblocks to be overcome to ultimately address unmet medical needs in the treatment of chronic HBV infection.
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Affiliation(s)
- Mirjam B Zeisel
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France Université de Strasbourg, Strasbourg, France
| | - Julie Lucifora
- Inserm U1052, CNRS UMR 5286, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL), Lyon, France
| | | | - Camille Sureau
- INTS, Laboratoire de Virologie Moléculaire, Paris, France
| | - Jürgen Beck
- Department of Internal Medicine 2/Molecular Biology, University Hospital Freiburg, Freiburg, Germany
| | - Massimo Levrero
- Center for Life Nanosciences (CNLS)-IIT/Sapienza, Rome, Italy Laboratory of Gene Expression, Department of Internal Medicine (DMISM), Sapienza University of Rome, Italy
| | - Michael Kann
- Université de Bordeaux, Microbiologie fondamentale et Pathogénicité, UMR 5234, Bordeaux, France CNRS, Microbiologie fondamentale et Pathogénicité, UMR 5234, Bordeaux, France CHU de Bordeaux, Bordeaux, France
| | - Percy A Knolle
- Technische Universität München, Institut für Molekulare Immunologie, München, Germany
| | - Monsef Benkirane
- Institut de Génétique Humaine, Laboratoire de Virologie Moléculaire, CNRS UPR1142, Montpellier, France
| | - David Durantel
- Inserm U1052, CNRS UMR 5286, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL), Lyon, France
| | - Marie-Louise Michel
- Laboratoire de Pathogenèse des Virus de l'Hépatite B, Département de Virologie, Institut Pasteur, Paris, France
| | - Brigitte Autran
- Laboratory of Immunity and Infection, Inserm U945, Paris, France Laboratory of Immunity and Infection, UPMC University Paris 06, Unité mixte de recherche-S945, Paris, France Inserm, IFR 113, Immunité-Cancer-Infection, Paris, France
| | - François-Loïc Cosset
- CIRI-International Center for Infectiology Research, Team EVIR, Université de Lyon, Lyon, France. Inserm, U1111, Lyon, France Ecole Normale Supérieure de Lyon, Lyon, France. CNRS, UMR5308, Lyon, France LabEx Ecofect, Université de Lyon, Lyon, France
| | | | - Christian Trépo
- Inserm U1052, CNRS UMR 5286, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL), Lyon, France Department of Hepatology, Croix-Rousse Hospital, Hospices Civils de Lyon, Lyon, France
| | - Jia-Horng Kao
- Department of Internal Medicine, Department of Medical Research, Graduate Institute of Clinical Medicine, and Hepatitis Research Center, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
| | - Fabrice Carrat
- Inserm, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France Sorbonne Universités, UPMC Univ Paris 06, Paris, France Assistance Publique Hôpitaux de Paris, Hôpital Saint Antoine, Paris, France
| | - Karine Lacombe
- Inserm, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France Sorbonne Universités, UPMC Univ Paris 06, Paris, France Assistance Publique Hôpitaux de Paris, Hôpital Saint Antoine, Paris, France
| | - Raymond F Schinazi
- Center for AIDS Research, Emory University School of Medicine and Veterans Affairs Medical Center, Atlanta, Georgia, USA
| | - Françoise Barré-Sinoussi
- Inserm and Unit of Regulation of Retroviral Infections, Department of Virology, Institut Pasteur, Paris, France
| | | | - Fabien Zoulim
- Inserm U1052, CNRS UMR 5286, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL), Lyon, France Department of Hepatology, Croix-Rousse Hospital, Hospices Civils de Lyon, Lyon, France
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12
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Abstract
The hepatitis B virus (HBV) is a widespread human pathogen that causes liver inflammation, cirrhosis, and hepatocellular carcinoma (HCC). Recent sequencing technologies have refined our knowledge of the genomic landscape and pathogenesis of HCC, but the mechanisms by which HBV exerts its oncogenic role remain controversial. In a prevailing view, inflammation, liver damage, and regeneration may foster the accumulation of genetic and epigenetic defects leading to cancer onset. However, a more direct and specific contribution of the virus is supported by clinical and biological observations. Among genetically heterogeneous HCCs, HBV-related tumors display high genomic instability, which may be attributed to the ability of HBV to integrate its DNA into the host cell genome, provoking chromosomal alterations and insertional mutagenesis of cancer genes. The viral transactivator HBx may also participate in transformation by deregulating diverse cellular machineries. A better understanding of the complex mechanisms linking HBV to HCC will improve prevention and treatment strategies.
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Affiliation(s)
- Marie-Annick Buendia
- Pathogenesis and Treatment of Acute Hepatitis and Liver Cancer Unit, INSERM U785, University Paris-Sud, Paul Brousse Hospital, 94800 Villejuif, France
| | - Christine Neuveut
- Hepacivirus and Innate Immunity Unit, URA CNRS 3015, Institut Pasteur, 75015 Paris, France
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13
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Abstract
In silico screening of metazoan genome data identified multiple endogenous hepadnaviral elements in the budgerigar (Melopsittacus undulatus) genome, most notably two elements comprising about 1.3 × and 1.0 × the full-length genome. Phylogenetic and molecular dating analyses show that endogenous budgerigar hepatitis B viruses (eBHBV) share an ancestor with extant avihepadnaviruses and infiltrated the budgerigar genome millions of years ago. Identification of full-length genomes with preserved key features like ε signals could enable resurrection of ancient BHBV.
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14
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Buendia MA, Paterlini‐Bréchot P, Tiollais P, Bréchot C. Hepatocellular Carcinoma: Molecular Aspects in Hepatitis B. VIRAL HEPATITIS 2005:269-294. [DOI: 10.1002/9780470987131.ch17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2025]
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15
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Bonilla Guerrero R, Roberts LR. The role of hepatitis B virus integrations in the pathogenesis of human hepatocellular carcinoma. J Hepatol 2005; 42:760-77. [PMID: 15826727 DOI: 10.1016/j.jhep.2005.02.005] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Ruben Bonilla Guerrero
- Center for Basic Research in Digestive Diseases, Division of Gastroenterology and Hepatology and Mayo Clinic Cancer Center, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
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16
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Momosaki S, Hsia CC, Nakashima Y, Kojiro M, Tabor E. Integration of hepatitis B virus containing mutations in the core promoter/X gene in patients with hepatocellular carcinoma. Dig Liver Dis 2003; 35:795-800. [PMID: 14674670 DOI: 10.1016/s1590-8658(03)00462-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
UNLABELLED Integration of hepatitis B virus is thought to be an essential step in hepatitis B virus associated hepatocarcinogenesis. Mutations at nucleotides 1762 and 1764 in the hepatitis B virus, within a sequence encoding both the core promoter gene and the X gene, have been found frequently in patients with hepatocellular carcinoma. However, integration of these mutant sequences has not been reported to date. METHODS A 228-base pair segment of the hepatitis B virus core promoter gene was amplified from hepatocellular carcinomas and adjacent non-tumourous liver tissue by nested PCR and sequenced. Integration of hepatitis B virus into human genomic DNA was investigated using the 'genome walking' method. RESULTS Point mutations were found in both hepatitis B virus nucleotides 1762 and 1764 in 8 of 14 hepatocellular carcinoma tissues (57%) and in 11 of 14 adjacent non-tumourous liver tissues (79%). Three patients were evaluated using the 'genome walking' method; all were found to have hepatitis B virus DNA integrated in their hepatocellular carcinoma (two patients) and/or in their non-tumourous liver tissue (three patients). Integration occurred in all tissues near host genomic sites that are prone to integration. Hepatitis B virus was integrated at or near the hepatitis B virus DR1 site in all samples, and all contained truncated X gene sequences that have been reported to be capable of producing fusion transcripts with transactivation potential. CONCLUSIONS Integrated hepatitis B virus DNA containing core promoter mutations at nucleotides 1762 and 1764 was found in hepatocellular carcinoma and/or adjacent non-tumourous liver tissue of three patients. These findings leave open the possibility that insertional mutagenesis or transactivation by fusion transcripts resulting from hepatitis B virus integration could play a role in hepatocarcinogenesis in some patients.
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Affiliation(s)
- S Momosaki
- Division of Emerging and Transfusion Transmitted Diseases, Food and Drug Administration, Center for Biologics Evaluation and Research, 1401 Rockville Pike, HFM-300, Rockville, MD 20852-1448, USA
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17
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Huang JM, Huang TH, Qiu HY, Fang XW, Zhuang TG, Liu HX, Wang YH, Deng LZ, Qiu JW. Effects of hepatitis B virus infection on human sperm chromosomes. World J Gastroenterol 2003; 9:736-40. [PMID: 12679922 PMCID: PMC4611440 DOI: 10.3748/wjg.v9.i4.736] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To evaluate the level of sperm chromosome aberrations in male patients with hepatitis B, and to directly detect whether there are HBV DNA integrations in sperm chromosomes of hepatitis B patients.
METHODS: Sperm chromosomes of 14 tested subjects (5 healthy controls, 9 patients with HBV infection, including 1 with acute hepatitis B, 2 with chronic active hepatitis B, 4 with chronic persistent hepatitis B, 2 chronic HBsAg carriers with no clinical symptoms) were prepared using interspecific in vitro fertilization between zona-free golden hamster ova and human spermatozoa, and the frequencies of aberration spermatozoa were compared between subjects of HBV infection and controls. Fluorescence in situ hybridization (FISH) to sperm chromosome spreads was carried out with biotin-labeled full length HBV DNA probe to detect the specific HBV DNA sequences in the sperm chromosomes.
RESULTS: The total frequency of sperm chromosome aberrations in HBV infection group (14.8%, 33/223) was significantly higher than that in the control group (4.3%, 5/116). Moreover, the sperm chromosomes in HBV infection patients commonly presented stickiness, clumping, failure to staining, etc, which would affect the analysis of sperm chromosomes. Specific fluorescent signal spots for HBV DNA were seen in sperm chromosomes of one patient with chronic persistent hepatitis. In 9 (9/42) sperm chromosome complements containing fluorescent signal spots, one presented 5 obvious FISH spots, others presented 2 to 4 signals. There was significant difference of fluorescence intensity among the signal spots. The distribution of signal sites among chromosomes was random.
CONCLUSION: HBV infection can bring about mutagenic effects on sperm chromosomes. Integrations of viral DNA into sperm chromosomes which are multisites and nonspecific, can further increase the instability of sperm chromosomes. This study suggested that HBV infection can create extensively hereditary effects by alteration genetic constituent and/or induction chromosome aberrations, as well as the possibility of vertical transmission of HBV via the germ line to the next generation.
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Affiliation(s)
- Jian-Min Huang
- Department of Cell Biology and Medical Genetics, Shantou University Medical College, Shantou 515031, Guangdong Province, China
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18
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Abstract
Hepatitis B virus (HBV) is at the origin of severe liver diseases like chronic active hepatitis, liver cirrhosis and hepatocellular carcinoma. There are some groups of patients with high risk of generation of HBV mutants: infected infants, immunosuppressed individuals (including hemodialysis patients), patients treated with interferon and lamivudine for chronic HBV infection. These groups are the target for molecular investigations reviewed in this paper. The emergence of lamivudine- or other antiviral-resistant variants, rises concern regarding long term use of these drugs. Infection or immunization with one HBV subtype confers immunity to all subtypes. However, reinfection or reactivation of latent HBV infection with HBV mutants have been reported in patients undergoing transplant and those infected with HIV. Mutations of the viral genome which are not replicative incompetent can be selected in further course of infection or under prolonged antiviral treatment and might maintain the liver disease. Four open reading frames (ORF) which are called S-gene, C-gene, X-gene and P-gene were identified within the HBV genome. Mutations may affect each of the ORFs. Mutated S-genes were described to be responsible for HBV-infections in successfully vaccinated persons, mutated C-genes were found to provoke severe chronic liver diseases, mutated X-genes could cause serious medical problems in blood donors by escaping the conventional test systems and mutated P-genes were considered to be the reason for chemotherapeutic drug resistance. This paper reviews molecular, immunological and clinical aspects of the HBV mutants.
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Affiliation(s)
- C Kreutz
- International Technology for Evaluation of Clinical Pharmacology, Paris, France.
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19
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Abstract
Topoisomerase I is a ubiquitous and essential enzyme in multicellular organisms. It is involved in multiple DNA transactions including DNA replication, transcription, chromosome condensation and decondensation, and probably DNA recombination. Besides its activity of DNA relaxation necessary to eliminate torsional stresses associated with these processes, topoisomerase I may have other functions related to its interaction with other cellular proteins. Topoisomerase I is the target of the novel anticancer drugs, the camptothecins. Recently a broad range of physiological and environmentally-induced DNA modifications have also been shown to poison topoisomerases. This review summarizes the various factors that enhance or suppress top1 cleavage complexes and discusses the significance of such effects. We also review the different mechanisms that have been proposed for the repair of topoisomerase I-mediated DNA lesions.
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Affiliation(s)
- P Pourquier
- Laboratory of Molecular Pharmacology, Division of Basic Sciences, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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20
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Zoulim F. Therapy of chronic hepatitis B virus infection: inhibition of the viral polymerase and other antiviral strategies. Antiviral Res 1999; 44:1-30. [PMID: 10588330 DOI: 10.1016/s0166-3542(99)00056-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Chronic hepatitis B infection remains a major public health problem worldwide. The hepatitis B virus belongs to the family of hepadnaviruses that replicate their DNA genome via a reverse transcription pathway. The chronicity of infection in infected hepatocytes is maintained by the persistence of the viral covalently closed circular DNA. The main strategies to combat chronic HBV infection rely on the stimulation of the specific antiviral immune response and on the inhibition of viral replication. While the prolonged administration of reverse transcriptase inhibitors is most often associated with a control of viral replication rather than eradication, it may select for resistant mutants. The search for new viral targets is therefore mandatory to design combination strategies to prevent the emergence of resistant mutants and eventually clear viral infection.
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21
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Abstract
Mammalian DNA topoisomerase I is a multifunctional enzyme which is essential for embryonal development. In addition to its classical DNA nicking-closing activities which are needed for relaxation of supercoiled DNA, topoisomerase I can phosphorylate certain splicing factors. The enzyme is also involved in transcriptional regulation through its ability to associate with other proteins in the TFIID-, and possibly TFIIH-, transcription complexes, and is implicated in the recognition of DNA lesions. Finally, topoisomerase I is a recombinase which can mediate illegitimate recombination. A crucial reaction intermediate during relaxation of DNA is the formation of a DNA-topoisomerase I complex (the cleavable complex) where topoisomerase I is covalently linked to a 3 -end of DNA thereby creating a single stranded DNA break. Cleavable complexes are also formed in the vicinity of DNA lesions and in the presence of the antitumor agent, camptothecin. While formation of cleavable complexes may be necessary for the initial stages of the DNA damage response, these complexes are also potentially dangerous to the cell due to their ability to mediate illegitimate recombination, which can lead to genomic instability and oncogenesis. Thus the levels and stability of these complexes have to be strictly regulated. This is obtained by maintaining the enzyme levels relatively constant, by limiting the stability of the cleavable complexes through physical interaction with the oncogene suppressor protein p53 and by degradation of the topoisomerase I by the proteasome system. Emerging evidence suggest that these regulatory functions are perturbed in tumor cells, explaining at the same time why topoisomerase I activities so often are increased in certain human tumors, and why these cells are sensitized to the cytotoxic effects of camptothecins.
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Affiliation(s)
- A K Larsen
- Institut Gustave-Roussy, Laboratory of Biology and Pharmacology of DNA Topoisomerases 39, Rue Camille Desmoulins, Villejuif, 94805, France.
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22
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Yamamoto T, Kajino K, Kudo M, Sasaki Y, Arakawa Y, Hino O. Determination of the clonal origin of multiple human hepatocellular carcinomas by cloning and polymerase chain reaction of the integrated hepatitis B virus DNA. Hepatology 1999; 29:1446-52. [PMID: 10216128 DOI: 10.1002/hep.510290523] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The poor prognosis of hepatocellular carcinoma (HCC) is partly the result of the high rate of recurrence that is caused either by intrahepatic metastasis (IM) or independent multicentric occurrence (MO). For convenience, discrimination of IM and MO is based on pathological findings, but reliable parameters are not sufficiently established. In the case of hepatitis B virus (HBV)-associated HCC, molecular discrimination of IM from MO can be achieved by comparison of integrated HBV DNAs. However, Southern blotting cannot be used for this purpose when one tumor is saved in frozen form and the other is in paraffin-embedded form. To solve this problem, we employed polymerase chain reaction (PCR) assays to confirm the clonality of primary and recurrent tumors. From the frozen tissue, we determined the junction between the integrated HBV and flanking genomic DNA by molecular cloning, and checked the existence of an identical junction in the DNA of paraffin-embedded tissue by PCR. Using this method, as well as Southern blotting, we proved in 6 of 8 patients that two nodular HCC lesions resected metachronously or simultaneously were caused by MO, while the remaining 2 cases were caused by IM. In 1 IM case, band patterns between two HCCs detected by Southern blotting were not identical.
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Affiliation(s)
- T Yamamoto
- Department of Experimental Pathology, Cancer Institute, Kami-Ikebukuro, Toshima-ku, Tokyo, Japan
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23
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Laskus T, Radkowski M, Wang LF, Nowicki M, Rakela J. Detection and sequence analysis of hepatitis B virus integration in peripheral blood mononuclear cells. J Virol 1999; 73:1235-8. [PMID: 9882326 PMCID: PMC103945 DOI: 10.1128/jvi.73.2.1235-1238.1999] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A PCR-based technique was used to detect hepatitis B virus (HBV) integration in peripheral blood mononuclear cells from patients with chronic hepatitis B. Integrated HBV DNA sequences, with virus-cell junctions located in the cohesive region between direct repeat 1 (DR1) and DR2, were found in 2 of 10 studied patients.
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Affiliation(s)
- T Laskus
- Division of Gastroenterology and Hepatology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15213, USA.
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24
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Pommier Y, Pourquier P, Fan Y, Strumberg D. Mechanism of action of eukaryotic DNA topoisomerase I and drugs targeted to the enzyme. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1400:83-105. [PMID: 9748515 DOI: 10.1016/s0167-4781(98)00129-8] [Citation(s) in RCA: 402] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
DNA topoisomerase I is essential for cellular metabolism and survival. It is also the target of a novel class of anticancer drugs active against previously refractory solid tumors, the camptothecins. The present review describes the topoisomerase I catalytic mechanisms with particular emphasis on the cleavage complex that represents the enzyme's catalytic intermediate and the site of action for camptothecins. Roles of topoisomerase I in DNA replication, transcription and recombination are also reviewed. Because of the importance of topoisomerase I as a chemotherapeutic target, we review the mechanisms of action of camptothecins and the other topoisomerase I inhibitors identified to date.
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Affiliation(s)
- Y Pommier
- Laboratory of Molecular Pharmacology, Division of Basic Sciences, National Cancer Institute, Bethesda, MD 20892-4255, USA.
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25
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Abstract
Hepatocellular carcinoma (HCC) is estimated to have an annual worldwide incidence of 0.25 to 1.2 million new cases per year. Both the prevalence and incidence of HCC vary markedly as a function of geography and the local prevalence of chronic viral hepatitis. Both chronic hepatitis B and chronic hepatitis C are recognized as risk factors for HCC. The prevalence of cirrhosis in individuals with HCC and chronic hepatitis B or C is reported to be 80.9% and 75.8%, respectively. HCC occurs at a lower rate in chronic viral hepatitis in the absence of cirrhosis. Moreover, hepatitis C virus (HCV) rather than hepatitis B virus (HBV) is associated with the majority of non-cirrhotic cases of HCC. It is probable that the ongoing process of hepatocyte necrosis and liver cell renewal coupled with inflammation, which is characteristic of chronic viral hepatitis, causes not only nodular regeneration and cirrhosis but also progressive genomic errors in hepatocytes as well as unregulated growth and repair mechanisms leading to hepatocyte dysplasia and, in some cases, hepatic carcinoma. Current concepts concerning virus-induced HCC are reported and discussed in the following review.
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Affiliation(s)
- R Idilman
- Transplant Center, Loyola University, Maywood, IL, USA
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26
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Zoulim F, Trépo C. Drug therapy for chronic hepatitis B: antiviral efficacy and influence of hepatitis B virus polymerase mutations on the outcome of therapy. J Hepatol 1998; 29:151-68. [PMID: 9696505 DOI: 10.1016/s0168-8278(98)80191-8] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- F Zoulim
- Inserm Unit 271, Hôtel Dieu Hospital, Lyon, France.
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27
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Laskus T, Radkowski M, Nowicki M, Wang LF, Vargas H, Rakela J. Association between hepatitis B virus core promoter rearrangements and hepatocellular carcinoma. Biochem Biophys Res Commun 1998; 244:812-4. [PMID: 9535748 DOI: 10.1006/bbrc.1998.8249] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hepatitis B virus (HBV) is the major etiological agent of hepatocellular carcinoma (HCC). Whether any particular viral variants are associated with HCC is unknown. We studied 53 Gambian patients with HCC and 33 HBsAg positive controls. A functional part of HBV core promoter and whole precore region were sequenced directly and/or after cloning. HBV DNA was amplified from sera from 27 HCC patients and in all controls. Fourteen (52%) patients and 12 (36%) controls (NS) were found to harbor an HBV strain with G to A transition mutation at position 1896 leading to HBeAg negative phenotype. Nine (33%) HCC patients and 2 (6%) controls (p < 0.01) harbored a mixture of wild type and HBV strains with deletions/insertions; strong consensus sequences for topoisomerase I breakage were located in the vicinity of these changes. In Africa, HCC is associated with HBV strains that have deletions/insertions in the HBV core promoter region.
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Affiliation(s)
- T Laskus
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pennsylvania, USA
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28
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Livezey KW, Simon D. Accumulation of genetic alterations in a human hepatoma cell line transfected with hepatitis B virus. Mutat Res 1997; 377:187-98. [PMID: 9247614 DOI: 10.1016/s0027-5107(97)00068-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Chromosome and molecular analyses of the hepatitis B virus (HBV)-transfected HepG2T14.1 variant of the HepG2 cell line was conducted. In HepG2T14.1 cells several genetic alterations such as de novo aberrations of chromosomes 9, 14, 15, and 20 were identified that are not present in the parental HepG2 cell line. Furthermore, HepG2T14.1 cells showed loss of heterozygosity (LOH) in the q region of chromosome 14. The single HBV integration site in HepG2T14.1 cells mapped to the 2q35-36 region of one copy of chromosome 2 by fluorescence in situ hybridization (FISH). No genetic changes were identified at or near the HBV integration site at the level of these analyses. In addition, growth rates in vivo and in vitro were dramatically accelerated in HepG2T14.1 cells. These results document that a HBV-transfected hepatoma cell line has de novo genetic mutations at several sites of the host genome, one HBV integration site in an non-rearranged chromosome and an altered phenotype. These findings support our hypothesis that HBV might play a role in cellular transformation by interfering with cellular processes responsible for the stability of the genome.
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Affiliation(s)
- K W Livezey
- Hahnemann School of Medicine, Department of Pathology and Laboratory Medicine, Philadelphia, PA 19129, USA
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29
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Aoki H, Kajino K, Arakawa Y, Hino O. Molecular cloning of a rat chromosome putative recombinogenic sequence homologous to the hepatitis B virus encapsidation signal. Proc Natl Acad Sci U S A 1996; 93:7300-4. [PMID: 8692987 PMCID: PMC38978 DOI: 10.1073/pnas.93.14.7300] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Previously, we reported that a 61-bp subgenomic HBV DNA sequence (designated as 15AB, nt 1855-1915) is a hot spot for genomic recombination and that a cellular protein binding to 15AB may be the putative recombinogenic protein. In the present study, we established the existence of a 15AB-like sequence in human and rat chromosomal DNA by Southern blot analysis. The 15AB-like sequence isolated from the rat chromosome demonstrated a 80.9% identity with 5'-CCAAGCTGTGCCTTGGGTGGC-3', at 1872-1892 of the hepatitis B virus genome, thought to be the essential region for recombination. Interestingly, this 15AB-like sequence also contained the pentanucleotide motifs GCTGG and CCAGC as an inverted repeat, part of the chi known hot spot for recombination in Escherichia coli. Importantly, a portion of the 15AB-like sequence is homologous (82.1%, 23/28 bp) to break point clusters of the human promyelocytic leukemia (PML) gene, characterized by a translocation [t(15;17)], and to rearranged mouse DNA for the immunoglobulin kappa light chain. Moreover, 15AB and 15AB-like sequences have striking homologies (12/15 = 80.0% and 13/15 = 86.7%, respectively) to the consensus sequence for topoisomerase II. Our present results suggest that this 15AB-like sequence in the rat genome might be a recombinogenic candidate triggering genomic instability in carcinogenesis.
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Affiliation(s)
- H Aoki
- Department of Experimental Pathology, Cancer Institue, Tokyo, Japan
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30
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Brechot C. Hepatitis B and C viruses and primary liver cancer. BAILLIERE'S CLINICAL GASTROENTEROLOGY 1996; 10:335-73. [PMID: 8864037 DOI: 10.1016/s0950-3528(96)90010-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The data presented indicate that viral agents (namely, HBV and HCV) are major environmental aetiological factors for human primary liver cancer. It is important to elucidate the molecular mechanisms further because HCC is one of the few examples of virus-related human cancers. In addition, the available evidence points to the possibility of at least partial prevention of the tumour by large-scale vaccination.
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Affiliation(s)
- C Brechot
- INSERM U370 and Liver Unit, CHU Necker, Paris, France
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31
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Choo KB, Chen CM, Han CP, Cheng WT, Au LC. Molecular analysis of cellular loci disrupted by papillomavirus 16 integration in cervical cancer: frequent viral integration in topologically destabilized and transcriptionally active chromosomal regions. J Med Virol 1996; 49:15-22. [PMID: 8732866 DOI: 10.1002/(sici)1096-9071(199605)49:1<15::aid-jmv3>3.0.co;2-n] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
To discern the structural features of cellular loci that are disrupted by type 16 human papillomavirus (HPV-16) integration in cervical cancer, a polymerase chain reaction (PCR)-based strategy was employed for direct amplification and sequence analysis of four such cellular loci in cancer biopsy samples. One of the HPV-16-disrupted loci was found to be the microtubule-associated protein (MAP-2) gene and the other three loci were uncharacterized and were designated PID-1 to -3 (for papillomavirus integration-disrupted). The junctional sequences of the viral integration sites in the four loci analyzed are bracketed by long tracts of homogeneous purine or pyrimidine or alternating purine-pyrimidine which are known to destabilize the B-form conformation of the DNA structure. Using a panel of human/hamster hybrid cell DNAs and PCR analysis, the four loci were assigned to chromosomes 2 (MAP-2), 9 (PID-1), 1 (PID-2) and 8 (PID-3), respectively. These chromosomes carry numerous other previously determined viral integration and chromosomal fragile sites and the myc oncogenes. The PID-1 locus was further found in Southern analysis to be rearranged and amplified in another cervical cancer biopsy and a cervical carcinoma cell line (CaSki). On Northern analysis, the PID-1 and -3 probes detected a 3.0- and a 3.6-kb transcript, respectively, in normal cervical cells and in cervical cancer cell lines. The findings suggest that HPV-16 genome integrates frequently into topologically destabilized and transcriptionally active chromosomal sites. It remains to be elucidated whether the MAP-2 and the PID loci contribute to the pathogenesis of cervical cancer.
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Affiliation(s)
- K B Choo
- Department of Medical Research and Education, Veterans General Hospital, Taipei, Taiwan, Republic of China
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32
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Gong SS, Jensen AD, Wang H, Rogler CE. Duck hepatitis B virus integrations in LMH chicken hepatoma cells: identification and characterization of new episomally derived integrations. J Virol 1995; 69:8102-8. [PMID: 7494330 PMCID: PMC189762 DOI: 10.1128/jvi.69.12.8102-8108.1995] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
While the cytoplasmic phase of the hepadnavirus replication cycle is well understood, very little is known about the nuclear phase. In contrast to retroviruses, proviral integration is not required for hepadnavirus replication; however, some of the viral DNAs in the nucleus are diverted into an integration pathway. Under certain conditions these integrations function as carcinogenic agents. In order to study the integration process, we have utilized LMH-D2 cells, which replicate wild-type duck hepatitis B virus (DHBV), to develop the first protocol to detect and characterize integrations of DHBV originating from episomal viral DNAs. Contrary to expectations, our results showed that stable new integrations are readily detectable in subclones of LMH-D2 cells. Complete characterization of one integration revealed a single-genome-length integrant with the structure of double-stranded linear (DSL) DHBV DNAs which are produced by in situ priming during viral replication. The integration contained a terminal redundancy of 6 bp from the r region of the virus DNA minus strand as well as a direct repeat of 70 bp of cellular DNA. On the basis of the structure of the integrant and the cellular DNA target site, we propose a molecular model for the integration mechanism that has some similarities to that of retroviruses. Identification of DSL hepadnavirus DNA integration suggests the possibility that modified DSL viral DNAs may be the precursors to a class of simple, unrearranged hepadnavirus integrations.
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Affiliation(s)
- S S Gong
- Marion Bessin Liver Research Center, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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33
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Gupta M, Fujimori A, Pommier Y. Eukaryotic DNA topoisomerases I. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1262:1-14. [PMID: 7772596 DOI: 10.1016/0167-4781(95)00029-g] [Citation(s) in RCA: 183] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- M Gupta
- Laboratory of Molecular Pharmacology, National Cancer Institute, National Institute of Health, Bethesda, MD 20892-4255, USA
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34
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Abstract
Some of the multiple factors involved in the molecular pathogenesis of hepatocellular carcinoma have been elucidated in recent years but no clear picture of how and in what sequence these factors interact at the molecular level has emerged yet. Transformation of hepatocytes to the malignant phenotype may occur irrespective of the aetiological agent through a pathway of chronic liver injury, regeneration and cirrhosis. The activation of cellular oncogenes, the inactivation of tumour suppressor genes and overexpression of certain growth factors contribute to the development of HCC. There is increasing evidence that the hepatitis B virus may play a direct role in the molecular pathogenesis of HCC. Aflatoxins have been shown to induce specific mutations of the p53 tumour suppressor gene thus providing a clue to how an environmental factor may contribute to tumour development at the molecular level.
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Affiliation(s)
- D Moradpour
- Molecular Hepatology Laboratory, Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown 02129, USA
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35
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Laskus T, Rakela J, Tong MJ, Nowicki MJ, Mosley JW, Persing DH. Naturally occurring hepatitis B virus mutants with deletions in the core promoter region. J Hepatol 1994; 20:837-41. [PMID: 7930487 DOI: 10.1016/s0168-8278(05)80158-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A novel class of hepatitis B virus mutants in patients with chronic hepatitis B is described. The predicted effect of the mutations is to disrupt the X open reading frame. The location of the genetic alterations within the putative precore promoter also suggests that they may ameliorate precore transcription, which would provide an alternate mechanism for HBeAg(-) escape variation. Definitive conclusions regarding the effects of these mutations must await additional in vitro and in vivo studies.
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Affiliation(s)
- T Laskus
- Mayo Clinic, Rochester, MN 55905
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36
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Tsuei DJ, Hsu TY, Chen JY, Chang MH, Hsu HC, Yang CS. Analysis of integrated hepatitis B virus DNA and flanking cellular sequences in a childhood hepatocellular carcinoma. J Med Virol 1994; 42:287-93. [PMID: 8006642 DOI: 10.1002/jmv.1890420316] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The DNA of tumor tissue K1 obtained at autopsy from a case of hepatocellular carcinoma (HCC) in a 9-year-old boy contained integrated hepatitis B virus (HBV) DNA at a single site in the chromosome (case 2, Chang et al.: Hepatology 13:316-320, 1991). To characterize further the integrated viral DNA sequences, a genomic library of the K1 DNA was constructed in the lambda L47.1 vector. One phage clone, designated KTM-1, containing integrated HBV DNA and cellular flanking sequences was obtained from this library. The restriction map and DNA sequence of this clone showed that the integrated HBV DNA was partially deleted and rearranged. The most conserved viral DNA sequences were surface and X genes and arranged in the opposite orientation. The viral core gene was not present. Using chloramphenicol acetyltransferase (CAT) assay, the C-terminal truncated X open reading frame was demonstrated to retain its trans-activating ability. The result suggested that the functional integrated X gene may play a role in hepatocarcinogenesis. The study also showed that the right cellular flanking sequences were human alphoid repetitive sequences.
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Affiliation(s)
- D J Tsuei
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Republic of China
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37
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Schirmacher P, Rogler CE, Dienes HP. Current pathogenetic and molecular concepts in viral liver carcinogenesis. VIRCHOWS ARCHIV. B, CELL PATHOLOGY INCLUDING MOLECULAR PATHOLOGY 1993; 63:71-89. [PMID: 8094924 DOI: 10.1007/bf02899246] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Hepatocellular carcinoma (HCC) is one of the most frequent malignancies in humans and in most cases a consequence of chronic infection of the liver by hepatotropic viruses (Hepatitis B Virus (HBV) and possibly Hepatitis C Virus (HCV)). Formation of HCC results from a stepwise process involving different preneoplastic lesions that reflect multiple genetic events, like protooncogene activation, tumor suppressor gene inactivation, and growth factor over- or reexpression. Recent investigations have gained new insights into how these factors are activated and may interact. In addition, improved knowledge of the molecular biology of HBV has led to better understanding of its pleiotropic effects on induction and progression in hepatocarcinogenesis.
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Affiliation(s)
- P Schirmacher
- Institute of Pathology, University Hospital, Mainz, Federal Republic of Germany
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38
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Kew MC, Miller RH, Chen HS, Tennant BC, Purcell RH. Mutant woodchuck hepatitis virus genomes from virions resemble rearranged hepadnaviral integrants in hepatocellular carcinoma. Proc Natl Acad Sci U S A 1993; 90:10211-5. [PMID: 8234278 PMCID: PMC47744 DOI: 10.1073/pnas.90.21.10211] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Although hepadnaviruses are implicated in the etiology of hepatocellular carcinoma, the pathogenic mechanisms involved remain uncertain. Clonally propagated integrations of hepadnaviral DNA into cellular DNA can be demonstrated in most virally induced hepatocellular carcinomas. Integration occurs at random sites in cellular DNA, but the highly preferred sites in viral DNA are adjacent to the directly repeated sequence DR1, less often DR2, or in the cohesive overlap region. Integrants invariably contain simple deletions or complex rearrangements that have been thought to occur after integration. We report here the detection of mutant woodchuck hepatitis virus (WHV) genomes cloned from virions in serum that are strikingly similar to the rearranged hepadnaviral genomes found previously as integrated sequences in cellular DNA. Of 102 cloned genomes studied, 2 had large inverted duplications, 1 a 219-nucleotide direct duplication, and 1 a 219-nucleotide deletion. Virus-virus DNA junctions occurred either adjacent to DR1 or DR2 or in the cohesive overlap region at preferred topoisomerase I cleavage sites. Since these sites are located in the single-stranded regions of the genome, cleavage by topoisomerase I would produce linear molecules that would be expected to be highly recombinogenic since this enzyme, possessing nicking and ligating activities, would remain covalently attached. Sucrose density gradient centrifugation coupled with polymerase chain reaction studies confirmed that the mutant WHV DNA forms resided in virions and did not represent free viral DNA released from infected cells or were unlikely to be an artifact of the cloning process. Thus, the finding in virions of mutant WHV DNA similar to WHV DNA integrated into cellular DNA suggests that the processes of mutation and integration are linked in some instances. Furthermore, the mutant genomes that are preferentially integrated into cellular DNA may have an etiologic role in hepatocarcinogenesis.
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MESH Headings
- Animals
- Base Sequence
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/microbiology
- Centrifugation, Density Gradient
- Cloning, Molecular
- DNA Topoisomerases, Type I/metabolism
- DNA, Neoplasm/genetics
- DNA, Neoplasm/isolation & purification
- DNA, Viral/blood
- DNA, Viral/genetics
- DNA, Viral/isolation & purification
- Gene Rearrangement
- Genome, Viral
- Hepadnaviridae/genetics
- Hepadnaviridae/isolation & purification
- Hepatitis B Virus, Woodchuck/genetics
- Liver Neoplasms/genetics
- Liver Neoplasms/microbiology
- Marmota/microbiology
- Molecular Sequence Data
- Polymerase Chain Reaction
- Virion/genetics
- Virion/isolation & purification
- Virus Integration
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Affiliation(s)
- M C Kew
- Hepatitis Viruses Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
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39
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Kew MC. Do mutant woodchuck hepatitis viruses play a role in hepatocellular carcinogenesis? RESEARCH IN VIROLOGY 1993; 144:293-6. [PMID: 8210711 DOI: 10.1016/s0923-2516(06)80043-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Although hepadnaviruses are implicated in the aetiology of hepatocellular carcinoma, the pathogenic mechanisms involved remain uncertain. Clonally propagated integrations of hepadnaviral DNA into cellular DNA can be demonstrated in most virally induced hepatocellular carcinomas. Integration occurs at random sites in cellular DNA, but the highly preferred sites in viral DNA are adjacent to the directly repeated sequence, DR1, less often DR2, or in the cohesive overlap region. Integrants invariably contain simple deletions or complex rearrangements that have been thought to occur after integration. We report here the detection, in the serum of woodchucks with hepatocellular carcinoma, of mutant woodchuck hepatitis viruses that are strikingly similar to the rearranged genomes found previously as integrated sequences in cellular DNA. Of the four mutants studied, two had large inverted duplications, one a 219 nucleotide direct duplication, and one a 219 nucleotide deletion. Virus-virus DNA junctions occurred either adjacent to DR1 or DR2 or in the cohesive overlap region at topoisomerase I cleavage sites. Thus, it is possible that rearrangement of the hepadnavirus genome precedes integration of viral DNA into cellular DNA and that mutant genomes that are preferentially integrated into cellular DNA have an aetiological role in hepatocarcinogenesis.
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MESH Headings
- Animals
- Carcinoma, Hepatocellular/etiology
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/microbiology
- DNA Topoisomerases, Type I/metabolism
- DNA, Viral/blood
- DNA, Viral/genetics
- Gene Rearrangement/genetics
- Hepatitis B/complications
- Hepatitis B/genetics
- Hepatitis B Virus, Woodchuck/genetics
- Hepatitis B Virus, Woodchuck/isolation & purification
- Liver Neoplasms, Experimental/etiology
- Liver Neoplasms, Experimental/genetics
- Liver Neoplasms, Experimental/microbiology
- Marmota/microbiology
- Mutation/genetics
- Repetitive Sequences, Nucleic Acid/genetics
- Virus Integration
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Affiliation(s)
- M C Kew
- Department of Medicine, Witwatersrand University Medical School, Johannesburg, South Africa
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40
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Abstract
Chronic infections with hepatitis B virus (HBV) of humans and animal hepadnavirus infections in their natural hosts are strongly associated with primary hepatocellular carcinoma (HCC). Although viral integrations are found in cells of many HCC, no general viral-specific hepatocarcinogenic mechanism for hepadnaviruses has been identified. In approximately one half of HCC in woodchuck hepatitis virus (WHV) infected woodchucks, viral integrations near the c-myc or N-myc genes have been reported which result in enhanced expression of the respective gene. Such host gene-specific insertional mutagenesis has not been found in HCC of other hepadnavirus infected hosts. Thus in humans, ground squirrels and ducks hepadnaviral integrations appear to be at different host chromosomal DNA sites in each HCC and few integrations have been found within or near any cellular gene. Other possible hepadnavirus-specific carcinogenic mechanisms that are being investigated include transactivation of cellular gene expression by an hepadnavirus gene product (e.g. the X-gene), and mutation of host genes by unknown hepadnavirus-specific mechanisms. It should be noted, however, that chronic hepadnavirus infection is associated with chronic necroinflammatory liver disease with hepatocellular necrosis and regeneration (sometimes leading to cirrhosis in humans), a pathological process that is common to numerous other risk factors for HCC. This suggests the possibility that this pathological process is hepatocarcinogenic irrespective of the inciting agent and the role of hepadnavirus infection is no different from that of other risk factors in causing chronic necroinflammatory liver disease.
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Affiliation(s)
- W S Robinson
- Stanford University School of Medicine, California
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41
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Abstract
For many years, epidemiological studies have demonstrated a strong link between chronic hepatitis B virus (HBV) infection and the development of primary hepatocellular carcinoma (PHC). Other hepatocarcinogens such as hepatitis C virus and aflatoxin also contribute to hepatocarcinogenesis either in conjunction with HBV infection or alone. Cellular and molecular biological studies are providing explanations for the HBV-PHC relationship, and models are now being formulated to further test the relative importance of various factors such as viral DNA integration, activation of oncogenes, genetic instability, loss of tumor suppressor genes, and trans-activating properties of HBV to the pathogenesis of PHC. Further research will probably define more than a single mechanism whereby chronic HBV infection results in PHC.
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Affiliation(s)
- M Feitelson
- Department of Pathology and Cell Biology, Jefferson Medical School, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
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42
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Bova R, Micheli MR, Nardiello S. Molecular biology of hepatocellular carcinoma and hepatitis B virus association. INTERNATIONAL JOURNAL OF CLINICAL & LABORATORY RESEARCH 1992; 21:190-8. [PMID: 1667738 DOI: 10.1007/bf02591643] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The involvement of the hepatitis B virus in the pathogenesis of hepatocellular carcinoma was initially suggested on the basis of epidemiological studies. In recent years several kinds of experimental evidence have supported this hypothesis; however, the role played by hepatitis B virus in hepatocarcinogenesis still needs to be elucidated. Several groups of researchers are presently involved in establishing whether hepatitis B virus makes a specific genetic contribution to carcinogenesis or predisposes to neoplastic transformation by causing chronic inflammation and cell regeneration. A comprehensive examination of the data available in the literature suggests that the two hypotheses may not be mutually exclusive.
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MESH Headings
- Animals
- Carcinoma, Hepatocellular/epidemiology
- Carcinoma, Hepatocellular/etiology
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/microbiology
- Case-Control Studies
- Chromosome Aberrations
- Cocarcinogenesis
- DNA, Viral/genetics
- Gene Amplification
- Gene Expression Regulation, Neoplastic
- Gene Expression Regulation, Viral
- Genes, Recessive
- Genetic Predisposition to Disease
- Genome, Viral
- Hepatitis B/complications
- Hepatitis B virus/genetics
- Hepatitis B virus/pathogenicity
- Hepatitis, Viral, Animal/complications
- Hepatitis, Viral, Animal/microbiology
- Humans
- Incidence
- Liver Neoplasms/epidemiology
- Liver Neoplasms/etiology
- Liver Neoplasms/genetics
- Liver Neoplasms/microbiology
- Liver Neoplasms, Experimental/microbiology
- Liver Regeneration
- Models, Biological
- Proto-Oncogenes
- Tumor Cells, Cultured
- Virus Integration
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Affiliation(s)
- R Bova
- Istituto Internazionale di Genetica e Biofisica, CNR, Naples, Italy
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43
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Affiliation(s)
- K Okuda
- Department of Medicine, Chiba University Hospital, Japan
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44
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Affiliation(s)
- M A Buendia
- Département des Rétrovirus, INSERM U163, Institut Pasteur, Paris, France
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45
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Tokino T, Tamura H, Hori N, Matsubara K. Chromosome deletions associated with hepatitis B virus integration. Virology 1991; 185:879-82. [PMID: 1962459 DOI: 10.1016/0042-6822(91)90564-r] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Integrated hepatitis B virus (HBV) DNA is often found in hepatocellular carcinomas which develop in HBV carriers. We previously found that chromosomal abnormalities such as translocations and inversions are often associated with HBV integration. Here we report deletions that were found with three integrants, by comparing the physical maps of the flanking cellular DNA of the integrants with those of the unoccupied cellular sequences. The sizes of the deletions were 25, 12, and 11 kb, respectively. Each integrant carried only a small fragment of the viral genome, from which the cohesive end region, the preferred site of integration, was deleted. We speculate that these deletions were made from primary integrants by recombination of regions between the viral DNA and the flanking cellular sequence.
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Affiliation(s)
- T Tokino
- Institute for Molecular and Cellular Biology, Osaka University, Japan
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46
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Hino O, Tabata S, Hotta Y. Evidence for increased in vitro recombination with insertion of human hepatitis B virus DNA. Proc Natl Acad Sci U S A 1991; 88:9248-52. [PMID: 1656466 PMCID: PMC52691 DOI: 10.1073/pnas.88.20.9248] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Chromosomal translocation, deletion, and inversion/duplication directly linked to hepatitis B virus (HBV) DNA integration occur frequently in host DNA of human hepatocellular carcinomas. To test the possible recombinogenic effect of HBV DNA, we have utilized an in vitro recombination assay. Fragments containing the region spanning DR1, which is believed to be the origin of viral replication and a preferred site in the viral genome for integration, increased the recombination events reproducibly in the presence of extracts from actively dividing cells (e.g., hepatocellular carcinoma) but not resting cells (e.g., normal liver). Moreover, in these extracts we have found a protein(s) that specifically binds to these HBV DNA fragments. These results support the notion that in some instances integrated HBV DNAs cause further genomic instability, possibly involving specific cellular protein(s). The fact that extracts from nondividing, normal liver did not increase recombination events suggests that genomic instability depends upon active cellular growth, a feature more commonly found subsequent to HBV-induced hepatocellular injury than in healthy liver. Our results offer an explanation for the high incidence of liver cancer that accompanies chronic hepatitis and add HBV to the list of agents that can cause genetic recombination.
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Affiliation(s)
- O Hino
- Department of Pathology, Cancer Institute, Tokyo, Japan
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47
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Paterlini P, Bréchot C. The detection of hepatitis B virus (HBV) in HBsAG negative individuals with primary liver cancer. Dig Dis Sci 1991; 36:1122-9. [PMID: 1650688 DOI: 10.1007/bf01297458] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The importance of chronic hepatitis B virus (HBV) infection in the development of primary liver cancer has been established by epidemiological studies. However, the evidence for a direct role of the virus in liver carcinogenesis is still tentative. In addition, the findings of HBV DNA sequences in HBsAg-negative subjects with liver cancer has been reported, although it is controversial. Here we report the use of the polymerase chain reaction to detect HBV DNA in the serum and liver of HBsAg-negative patients. This technique allows both for the detection and cloning of HBV variants. In addition, the demonstration of HBV DNA and RNA molecules in HCC of HBsAg-negative individuals as determined by standard techniques reinforces the role of HBV in the pathogenesis of this tumor.
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Affiliation(s)
- P Paterlini
- INSERM U-75, Unité d'Hépatologie, CHU Laënnec-Necker, Paris, France
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48
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Hilger C, Velhagen I, Zentgraf H, Schröder CH. Diversity of hepatitis B virus X gene-related transcripts in hepatocellular carcinoma: a novel polyadenylation site on viral DNA. J Virol 1991; 65:4284-91. [PMID: 1649331 PMCID: PMC248866 DOI: 10.1128/jvi.65.8.4284-4291.1991] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
RNA was isolated from tissue of two patients with hepatocellular carcinoma developed on the background of a chronic hepatitis B virus infection. For identification and characterization of 3' ends of X gene open reading frame (ORF)-related transcripts, RNA was reverse transcribed into cDNA and subjected to polymerase chain reaction. Cloned amplification products from tumor tissue of one patient represented an approximately even distribution of transcripts terminating at the established poly(A) signal (standard transcripts) and of truncated transcripts terminating at a CATAAA poly(A) signal within the 3' end region of X gene ORF (truncated transcripts). Amplified cDNA from tumor tissue of the second patient could be attributed mainly to the standard type of transcripts, whereas cDNA from the nontumor tissue of the same patient could be assigned to four groups of transcripts: (i) standard transcripts, (ii) transcripts with internal deletions affecting the 3' end of the X gene, (iii) truncated transcripts, and (iv) hybrid transcripts displaying 5' sequences from the X gene ORF fused to cellular sequences.
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Affiliation(s)
- C Hilger
- Institut für Virusforschung/ATV, Deutsches Krebsforschungszentrum, Heidelberg, Germany
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49
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Abstract
Hepadnaviruses integrate in cellular DNA via an illegitimate recombination mechanism, and clonally propagated integrations are present in most hepatocellular carcinomas which arise in hepadnavirus carriers. Although integration is not specific for any viral or cellular sequence, highly preferred integration sites have been identified near the DR1 and DR2 sequences and in the cohesive overlap region of virion DNA. We have mapped a set of preferred topoisomerase I (Topo I) cleavage sites in the region of DR1 on plus-strand DNA and in the cohesive overlap near DR2 and have tested whether Topo I is capable of mediating illegitimate recombination of woodchuck hepatitis virus (WHV) DNA with cellular DNA by developing an in vitro assay for Topo I-mediated linking. Four in vitro-generated virus-cell hybrid molecules have been cloned, and sequence analysis demonstrated that Topo I can mediate both linkage of WHV DNA to 5'OH acceptor ends of heterologous DNA fragments and linkage of WHV DNA into internal sites of a linear double-stranded cellular DNA. The in vitro integrations occurred at preferred Topo I cleavage sites in WHV DNA adjacent to the DR1 and were nearly identical to a subset of integrations cloned from hepatocellular carcinomas. The end specificity and polarity of viral sequences in the integrations allows us to propose a prototype integration mechanism for both ends of a linearized hepadnavirus DNA molecule.
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Affiliation(s)
- H P Wang
- Marion Bessin Liver Research Center, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461
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50
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Woodchuck hepatitis virus is a more efficient oncogenic agent than ground squirrel hepatitis virus in a common host. J Virol 1991; 65:1673-9. [PMID: 2002538 PMCID: PMC239970 DOI: 10.1128/jvi.65.4.1673-1679.1991] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Chronic infection with hepatitis B viruses (hepadnaviruses) is a major cause of hepatocellular carcinoma (HCC), but the incubation time varies from 1 to 2 years to several decades in different host species infected with indigenous viruses. To discern the influence of viral and host factors on the kinetics of induction of HCC, we exploited the recent observation that ground squirrel hepatitis virus (GSHV) is infectious in woodchucks (C. Seeger, P. L. Marion, D. Ganem, and H. E. Varmus, J. Virol. 61:3241-3247, 1987) to compare the pathogenic potential of GSHV and woodchuck hepatitis virus (WHV) in chronically infected woodchucks. Chronic GSHV infection in woodchucks produces mild to moderate portal hepatitis, similar to that observed in woodchucks chronically infected with WHV. However, HCC developed in GSHV carriers about 18 months later than in WHV carriers. Thus, although both viruses are oncogenic in woodchucks, GSHV and WHV differ in oncogenic determinants that can affect the kinetics of appearance of HCC in chronically infected animals.
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