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Stella L, Santopaolo F, Gasbarrini A, Pompili M, Ponziani FR. Viral hepatitis and hepatocellular carcinoma: From molecular pathways to the role of clinical surveillance and antiviral treatment. World J Gastroenterol 2022; 28:2251-2281. [PMID: 35800182 PMCID: PMC9185215 DOI: 10.3748/wjg.v28.i21.2251] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 12/08/2021] [Accepted: 04/26/2022] [Indexed: 02/06/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is a global health challenge. Due to the high prevalence in low-income countries, hepatitis B virus (HBV) and hepatitis C virus infections remain the main risk factors for HCC occurrence, despite the increasing frequencies of non-viral etiologies. In addition, hepatitis D virus coinfection increases the oncogenic risk in patients with HBV infection. The molecular processes underlying HCC development are complex and various, either independent from liver disease etiology or etiology-related. The reciprocal interlinkage among non-viral and viral risk factors, the damaged cellular microenvironment, the dysregulation of the immune system and the alteration of gut-liver-axis are known to participate in liver cancer induction and progression. Oncogenic mechanisms and pathways change throughout the natural history of viral hepatitis with the worsening of liver fibrosis. The high risk of cancer incidence in chronic viral hepatitis infected patients compared to other liver disease etiologies makes it necessary to implement a proper surveillance, both through clinical-biochemical scores and periodic ultrasound assessment. This review aims to outline viral and microenvironmental factors contributing to HCC occurrence in patients with chronic viral hepatitis and to point out the importance of surveillance programs recommended by international guidelines to promote early diagnosis of HCC.
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Affiliation(s)
- Leonardo Stella
- Internal Medicine and Gastroenterology, Hepatology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome 00168, Italy
| | - Francesco Santopaolo
- Internal Medicine and Gastroenterology, Hepatology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome 00168, Italy
| | - Antonio Gasbarrini
- Internal Medicine and Gastroenterology, Hepatology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome 00168, Italy
| | - Maurizio Pompili
- Internal Medicine and Gastroenterology, Hepatology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome 00168, Italy
| | - Francesca Romana Ponziani
- Internal Medicine and Gastroenterology, Hepatology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome 00168, Italy
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2
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Rahman N, Sun J, Li Z, Pattnaik A, Mohallem R, Wang M, Kazemian M, Aryal UK, Andrisani O. The cytoplasmic LSm1-7 and nuclear LSm2-8 complexes exert opposite effects on Hepatitis B virus biosynthesis and interferon responses. Front Immunol 2022; 13:970130. [PMID: 36016928 PMCID: PMC9396650 DOI: 10.3389/fimmu.2022.970130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/15/2022] [Indexed: 12/12/2022] Open
Abstract
Despite many studies on host or viral gene expression, how the cellular proteome responds to internal or external cues during the infection process remains unclear. In this study, we used a Hepatitis B Virus (HBV) replication model and performed proteomic analyses to understand how HBV evades innate immunity as a function of cell cycle progression. Specifically, we performed proteomic analyses of HBV-replicating cells in G1/S and G2/M phases, as a function of IFN-α treatment. We identified that the conserved LSm (Like-Sm1-8) proteins were differentially regulated in HBV replicating cells treated with IFN-α. Specifically, in G2/M phase, IFN-α increased protein level of LSm1, the unique subunit of cytoplasmic LSm1-7 complex involved in mRNA decay. By contrast, IFN-α decreased LSm8, the unique subunit of nuclear LSm2-8 complex, a chaperone of U6 spliceosomal RNA, suggesting the cytoplasmic LSm1-7 complex is antiviral, whereas the nuclear LSm2-8 complex is pro-viral. In HBV replication and infection models, siRNA-mediated knockdown of LSm1 increased all viral RNAs. Conversely, LSm8 knockdown reduced viral RNA levels, dependent on N6-adenosine methylation (m6A) of the epsilon stem-loop at the 5' end of pre-Core/pregenomic (preC/pg) RNA. Methylated RNA immunoprecipitation (MeRIP) assays demonstrated reduced viral RNA methylation by LSm8 knockdown, dependent on the 5' m6A modification, suggesting the LSm2-8 complex has a role in mediating this modification. Interestingly, splicing inhibitor Cp028 acting upstream of the LSm2-8 complex suppressed viral RNA levels without reducing the 5' m6A modification. This observation suggests Cp028 has novel antiviral effects, likely potentiating IFN-α-mediated suppression of HBV biosynthesis.
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Affiliation(s)
- Naimur Rahman
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, United States.,Purdue Center for Cancer Research, Purdue University, West Lafayette, IN, United States
| | - Jiazeng Sun
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, United States.,Purdue Center for Cancer Research, Purdue University, West Lafayette, IN, United States
| | - Zhili Li
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, United States.,Purdue Center for Cancer Research, Purdue University, West Lafayette, IN, United States
| | - Aryamav Pattnaik
- Purdue Center for Cancer Research, Purdue University, West Lafayette, IN, United States.,Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Rodrigo Mohallem
- Purdue Proteomics Facility, Bindley Bioscience Center, Purdue University, West Lafayette, IN, United States.,Department of Comparative Pathobiology, Purdue University, West Lafayette, IN, United States
| | - Mengbo Wang
- Purdue Center for Cancer Research, Purdue University, West Lafayette, IN, United States.,Department of Biochemistry, Purdue University, West Lafayette, IN, United States
| | - Majid Kazemian
- Purdue Center for Cancer Research, Purdue University, West Lafayette, IN, United States.,Department of Biochemistry, Purdue University, West Lafayette, IN, United States.,Department of Computer Science, Purdue University, West Lafayette, IN, United States
| | - Uma K Aryal
- Purdue Proteomics Facility, Bindley Bioscience Center, Purdue University, West Lafayette, IN, United States.,Department of Comparative Pathobiology, Purdue University, West Lafayette, IN, United States
| | - Ourania Andrisani
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, United States.,Purdue Center for Cancer Research, Purdue University, West Lafayette, IN, United States
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3
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Sladky VC, Eichin F, Reiberger T, Villunger A. Polyploidy control in hepatic health and disease. J Hepatol 2021; 75:1177-1191. [PMID: 34228992 DOI: 10.1016/j.jhep.2021.06.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/25/2021] [Accepted: 06/15/2021] [Indexed: 12/24/2022]
Abstract
A balanced increase in DNA content (ploidy) is observed in some human cell types, including bone-resorbing osteoclasts, platelet-producing megakaryocytes, cardiomyocytes or hepatocytes. The impact of increased hepatocyte ploidy on normal physiology and diverse liver pathologies is still poorly understood. Recent findings suggest swift genetic adaptation to hepatotoxic stress and the protection from malignant transformation as beneficial effects. Herein, we discuss the molecular mechanisms regulating hepatocyte polyploidisation and its implication for different liver diseases and hepatocellular carcinoma. We report on centrosomes' role in limiting polyploidy by activating the p53 signalling network (via the PIDDosome multiprotein complex) and we discuss the role of this pathway in liver disease. Increased hepatocyte ploidy is a hallmark of hepatic inflammation and may play a protective role against liver cancer. Our evolving understanding of hepatocyte ploidy is discussed from the perspective of its potential clinical application for risk stratification, prognosis, and novel therapeutic strategies in liver disease and hepatocellular carcinoma.
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Affiliation(s)
- Valentina C Sladky
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Felix Eichin
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Thomas Reiberger
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, 1090 Vienna, Austria; Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases (LBI-RUD), 1090 Vienna, Austria; CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Andreas Villunger
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria; Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases (LBI-RUD), 1090 Vienna, Austria; CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria.
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4
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Donne R, Sangouard F, Celton-Morizur S, Desdouets C. Hepatocyte Polyploidy: Driver or Gatekeeper of Chronic Liver Diseases. Cancers (Basel) 2021; 13:cancers13205151. [PMID: 34680300 PMCID: PMC8534039 DOI: 10.3390/cancers13205151] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/11/2021] [Accepted: 10/11/2021] [Indexed: 12/25/2022] Open
Abstract
Polyploidy, also known as whole-genome amplification, is a condition in which the organism has more than two basic sets of chromosomes. Polyploidy frequently arises during tissue development and repair, and in age-associated diseases, such as cancer. Its consequences are diverse and clearly different between systems. The liver is a particularly fascinating organ in that it can adapt its ploidy to the physiological and pathological context. Polyploid hepatocytes are characterized in terms of the number of nuclei per cell (cellular ploidy; mononucleate/binucleate hepatocytes) and the number of chromosome sets in each nucleus (nuclear ploidy; diploid, tetraploid, octoploid). The advantages and disadvantages of polyploidy in mammals are not fully understood. About 30% of the hepatocytes in the human liver are polyploid. In this review, we explore the mechanisms underlying the development of polyploid cells, our current understanding of the regulation of polyploidization during development and pathophysiology and its consequences for liver function. We will also provide data shedding light on the ways in which polyploid hepatocytes cope with centrosome amplification. Finally, we discuss recent discoveries highlighting the possible roles of liver polyploidy in protecting against tumor formation, or, conversely, contributing to liver tumorigenesis.
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Affiliation(s)
- Romain Donne
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
- Liver Cancer Program, Division of Liver Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, Tisch Cancer Institute, New York, NY 10029, USA
- Icahn School of Medicine at Mount Sinai, The Precision Immunology Institute, New York, NY 10029, USA
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Flora Sangouard
- Laboratory of Proliferation, Stress and Liver Physiopathology, Centre de Recherche des Cordeliers, F-75006 Paris, France;
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, F-75006 Paris, France
| | - Séverine Celton-Morizur
- Laboratory of Proliferation, Stress and Liver Physiopathology, Centre de Recherche des Cordeliers, F-75006 Paris, France;
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, F-75006 Paris, France
- Correspondence: (S.C.-M.); (C.D.)
| | - Chantal Desdouets
- Laboratory of Proliferation, Stress and Liver Physiopathology, Centre de Recherche des Cordeliers, F-75006 Paris, France;
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, F-75006 Paris, France
- Correspondence: (S.C.-M.); (C.D.)
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5
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Herbein G, Nehme Z. Polyploid Giant Cancer Cells, a Hallmark of Oncoviruses and a New Therapeutic Challenge. Front Oncol 2020; 10:567116. [PMID: 33154944 PMCID: PMC7591763 DOI: 10.3389/fonc.2020.567116] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/11/2020] [Indexed: 12/19/2022] Open
Abstract
Tumors are renowned as intricate systems that harbor heterogeneous cancer cells with distinctly diverse molecular signatures, sizes and genomic contents. Among those various genomic clonal populations within the complex tumoral architecture are the polyploid giant cancer cells (PGCC). Although described for over a century, PGCC are increasingly being recognized for their prominent role in tumorigenesis, metastasis, therapy resistance and tumor repopulation after therapy. A shared characteristic among all tumors triggered by oncoviruses is the presence of polyploidy. Those include Human Papillomaviruses (HPV), Epstein Barr Virus (EBV), Hepatitis B and C viruses (HBV and HCV, respectively), Human T-cell lymphotropic virus-1 (HTLV-1), Kaposi's sarcoma herpesvirus (KSHV) and Merkel polyomavirus (MCPyV). Distinct viral proteins, for instance Tax for HTLV-1 or HBx for HBV have demonstrated their etiologic role in favoring the appearance of PGCC. Different intriguing biological mechanisms employed by oncogenic viruses, in addition to viruses with high oncogenic potential such as human cytomegalovirus, could support the generation of PGCC, including induction of endoreplication, inactivation of tumor suppressors, development of hypoxia, activation of cellular senescence and others. Interestingly, chemoresistance and radioresistance have been reported in the context of oncovirus-induced cancers, for example KSHV and EBV-associated lymphomas and high-risk HPV-related cervical cancer. This points toward a potential linkage between the previously mentioned players and highlights PGCC as keystone cancer cells in virally-induced tumors. Subsequently, although new therapeutic approaches are actively needed to fight PGCC, attention should also be drawn to reveal the relationship between PGCC and oncoviruses, with the ultimate goal of establishing effective therapeutic platforms for treatment of virus-associated cancers. This review discusses the presence of PGCCs in tumors induced by oncoviruses, biological mechanisms potentially favoring their appearance, as well as their consequent implication at the clinical and therapeutic level.
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Affiliation(s)
- Georges Herbein
- Pathogens & Inflammation/EPILAB Laboratory, EA 4266, University of Franche-Comté, Université Bourgogne Franche-Comté (UBFC), Besançon, France.,Department of Virology, CHRU Besancon, Besançon, France
| | - Zeina Nehme
- Pathogens & Inflammation/EPILAB Laboratory, EA 4266, University of Franche-Comté, Université Bourgogne Franche-Comté (UBFC), Besançon, France.,Faculty of Sciences, Lebanese University, Beirut, Lebanon
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6
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Mani SKK, Yan B, Cui Z, Sun J, Utturkar S, Foca A, Fares N, Durantel D, Lanman N, Merle P, Kazemian M, Andrisani O. Restoration of RNA helicase DDX5 suppresses hepatitis B virus (HBV) biosynthesis and Wnt signaling in HBV-related hepatocellular carcinoma. Theranostics 2020; 10:10957-10972. [PMID: 33042264 PMCID: PMC7532671 DOI: 10.7150/thno.49629] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/11/2020] [Indexed: 02/07/2023] Open
Abstract
Rationale: RNA helicase DDX5 is downregulated during hepatitis B virus (HBV) replication, and poor prognosis HBV-related hepatocellular carcinoma (HCC). The aim of this study is to determine the mechanism and significance of DDX5 downregulation for HBV-driven HCC, and identify biologics to prevent DDX5 downregulation. Methods: Molecular approaches including immunoblotting, qRT-PCR, luciferase transfections, hepatosphere assays, Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq), and RNA-seq were used with cellular models of HBV replication, HBV infection, and HBV-related liver tumors, as well as bioinformatic analyses of liver cancer cells from two independent cohorts. Results: We demonstrate that HBV infection induces expression of the proto-oncogenic miR17~92 and miR106b~25 clusters which target the downregulation of DDX5. Increased expression of these miRNAs is also detected in HBV-driven HCCs exhibiting reduced DDX5 mRNA. Stable DDX5 knockdown (DDX5KD) in HBV replicating hepatocytes increased viral replication, and resulted in hepatosphere formation, drug resistance, Wnt activation, and pluripotency gene expression. ATAC-seq of DDX5KD compared to DDX5 wild-type (WT) cells identified accessible chromatin regions enriched in regulation of Wnt signaling genes. RNA-seq analysis comparing WT versus DDX5KD cells identified enhanced expression of multiple genes involved in Wnt pathway. Additionally, expression of Disheveled, DVL1, a key regulator of Wnt pathway activation, was significantly higher in liver cancer cells with low DDX5 expression, from two independent cohorts. Importantly, inhibitors (antagomirs) to miR17~92 and miR106b~25 restored DDX5 levels, reduced DVL1 expression, and suppressed both Wnt activation and viral replication. Conclusion : DDX5 is a negative regulator of Wnt signaling and hepatocyte reprogramming in HCCs. Restoration of DDX5 levels by miR17~92 / miR106b~25 antagomirs in HBV-infected patients can be explored as both antitumor and antiviral strategy.
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7
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Hu WY, Wei HY, Liu LY, Li KM, Wang RB, Xu XQ, Feng R. miR-3607, a biomarker of hepatocellular carcinoma invasion and aggressiveness: Its relationship with epithelial-mesenchymal transition process. IUBMB Life 2020; 72:1686-1697. [PMID: 32311821 DOI: 10.1002/iub.2291] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 03/31/2020] [Accepted: 04/03/2020] [Indexed: 01/13/2023]
Abstract
microRNA-3607 (miR-3607) has been identified as an important biomarker, and its aberrant expression exerts a significant role in tumorigenesis. However, the biological function of miR-3607 in hepatocellular carcinoma (HCC) needs to be deciphered comprehensively. Clinical samples of HCC patients, as well as normal cases, were derived from The Cancer Genome Atlas database. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting analyses were utilized to detect the expression levels of indicated genes. Cell counting kit-8 (CCK-8), colony formation, and transwell assays were performed to assess the effect of miR-3607 in HCC cell viability, migration, and invasion. Bioinformatics analysis and luciferase reporter gene assay was applied to screen the target genes of miR-3607 and verified the association between miR-3607 and its potential target gene. Our study showed that miR-3607 expression was decreased in HCC tissues and cell lines, and its downregulation was linked with poor outcomes of HCC patients. miR-3607 was noted to inhibit HCC cell growth, colony formation, migration, and invasion. Besides, minichromosome maintenance (MCM5) was a possible target gene of miR-3607 in HCC. Overexpression of MCM5 was observed in HCC and induced unfavorable prognosis. MCM5 expression had a negative correlation with miR-3607. MCM5 can abolish the suppressive impacts of miR-3607 on HCC cell malignant behaviors and the epithelial-mesenchymal transition (EMT) process. To sum up, our results unveiled that miR-3607 could inhibit HCC cell growth, migration, and invasion by regulating MCM5 and mediating EMT process, suggesting a new probable biomarker for further treatment of HCC.
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Affiliation(s)
- Wen-Yu Hu
- Department of chemotherapy, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academic of Medical Science, Jinan, People's Republic of China
| | - Hai-Yan Wei
- Department of Physical and Chemical Laboratory, Shandong Academy of Occupational Health and Occupational Medicine, Jinan, People's Republic of China
| | - Lu-Yun Liu
- Department of Physical and Chemical Laboratory, Shandong Academy of Occupational Health and Occupational Medicine, Jinan, People's Republic of China
| | - Ke-Ming Li
- Department of Pharmacology, Shandong Academy of Traditional Chinese Medicine, Jinan, People's Republic of China
| | - Ren-Ben Wang
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academic of Medical Science, Jinan, People's Republic of China
| | - Xiao-Qing Xu
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academic of Medical Science, Jinan, People's Republic of China
| | - Rui Feng
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academic of Medical Science, Jinan, People's Republic of China
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8
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Hepatitis B virus X protein promotes DNA damage propagation through disruption of liver polyploidization and enhances hepatocellular carcinoma initiation. Oncogene 2018; 38:2645-2657. [PMID: 30538294 DOI: 10.1038/s41388-018-0607-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 10/15/2018] [Accepted: 10/17/2018] [Indexed: 12/19/2022]
Abstract
Hepatitis B virus X protein (HBx) contributes to Hepatitis B virus (HBV)-related liver cancer. However, its impact on hepatocyte proliferation and genomic stability remains elusive. We studied the role of HBx expression on the progression of cell cycle and liver polyploidization during proliferation and liver carcinogenesis. Full-length HBx transgenic mice (FL-HBx) were developed to investigate liver ploidy as well as hepatocyte proliferation, along normal liver maturation and during cancer initiation (chemical carcinogen treatment). Investigation of postnatal liver development in FL-HBx showed an aberrant G1/S and G2/M transitions, triggered (1) a delay of the formation of hepatocytes binucleation, (2) the early synthesis of polyploidy nuclei (≥4n) and (3) DNA damage appearance. Moreover, HBV infection during hepatocytes proliferation in a humanized liver mouse model led, to modifications in polyploidy of hepatocytes. In initiation of hepatocellular carcinoma, FL-HBx protein decreased ChK1 phosphorylation, Mre11 and Rad51 expression, upregulated IL-6 expression and impaired apoptosis. This was related to DNA damage accumulation in FL-HBx mice. At day 75 after initiation of hepatocellular carcinoma, FL-HBx mice revealed significant cell cycle changes related to the increased amount of 4n nuclei and of markers of cancer progenitor cells. Finally, PLK1 upregulation and p38/ERK activation in FL-HBx mice were implicated in aberrant polyploidization favoring DNA damage propagation and hepatocyte transformation. In conclusion, our data indicate that FL-HBx protein increases DNA damage through the hijack of hepatocyte polyploidization. That leads to enhancement of hepatocellular carcinoma initiation in an inflammatory context.
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Mani SKK, Andrisani O. Hepatitis B Virus-Associated Hepatocellular Carcinoma and Hepatic Cancer Stem Cells. Genes (Basel) 2018; 9:genes9030137. [PMID: 29498629 PMCID: PMC5867858 DOI: 10.3390/genes9030137] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 02/23/2018] [Accepted: 02/23/2018] [Indexed: 02/06/2023] Open
Abstract
Chronic Hepatitis B Virus (HBV) infection is linked to hepatocellular carcinoma (HCC) pathogenesis. Despite the availability of a HBV vaccine, current treatments for HCC are inadequate. Globally, 257 million people are chronic HBV carriers, and children born from HBV-infected mothers become chronic carriers, destined to develop liver cancer. Thus, new therapeutic approaches are needed to target essential pathways involved in HCC pathogenesis. Accumulating evidence supports existence of hepatic cancer stem cells (hCSCs), which contribute to chemotherapy resistance and cancer recurrence after treatment or surgery. Understanding how hCSCs form will enable development of therapeutic strategies to prevent their formation. Recent studies have identified an epigenetic mechanism involving the downregulation of the chromatin modifying Polycomb Repressive Complex 2 (PRC2) during HBV infection, which results in re-expression of hCSC marker genes in infected hepatocytes and HBV-associated liver tumors. However, the genesis of hCSCs requires, in addition to the expression of hCSC markers cellular changes, rewiring of metabolism, cell survival, escape from programmed cell death, and immune evasion. How these changes occur in chronically HBV-infected hepatocytes is not yet understood. In this review, we will present the basics about HBV infection and hepatocarcinogenesis. Next, we will discuss studies describing the mutational landscape of liver cancers and how epigenetic mechanisms likely orchestrate cellular reprograming of hepatocytes to enable formation of hCSCs.
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Affiliation(s)
- Saravana Kumar Kailasam Mani
- Department of Basic Medical Sciences and Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
| | - Ourania Andrisani
- Department of Basic Medical Sciences and Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
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10
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Role of HBx in hepatitis B virus persistence and its therapeutic implications. Curr Opin Virol 2018; 30:32-38. [PMID: 29454995 DOI: 10.1016/j.coviro.2018.01.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/17/2018] [Accepted: 01/24/2018] [Indexed: 12/12/2022]
Abstract
Chronic hepatitis B virus infection is a significant risk factor for cirrhosis and hepatocellular carcinoma. The HBx protein is required for virus replication, but the lack of robust infection models has hindered our understanding of HBx functions that could be targeted for antiviral purposes. We briefly review three properties of HBx: its binding to DDB1 and its regulation of cell survival and metabolism, to illustrate how a single viral protein can have multiple effects in a cell. We propose that different functions of HBx are needed, depending on the changing hepatocyte environment encountered during a chronic virus infection, and that these functions might serve as novel therapeutic targets for inhibiting hepatitis B virus replication and the development of associated diseases.
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11
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Yuan Y, Ma XS, Liang QX, Xu ZY, Huang L, Meng TG, Lin F, Schatten H, Wang ZB, Sun QY. Geminin deletion in pre-meiotic DNA replication stage causes spermatogenesis defect and infertility. J Reprod Dev 2017; 63:481-488. [PMID: 28690291 PMCID: PMC5649097 DOI: 10.1262/jrd.2017-036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Geminin plays a critical role in cell cycle regulation by regulating DNA replication and serves as a transcriptional molecular switch that directs cell fate decisions. Spermatogonia lacking Geminin disappear
during the initial wave of mitotic proliferation, while geminin is not required for meiotic progression of spermatocytes. It is unclear whether geminin plays a role in pre-meiotic DNA replication in later-stage spermatogonia and
their subsequent differentiation. Here, we selectively disrupted Geminin in the male germline using the Stra8-Cre/loxP conditional knockout system.
Geminin-deficient mice showed atrophic testes and infertility, concomitant with impaired spermatogenesis and reduced sperm motility. The number of undifferentiated spermatogonia and spermatocytes was significantly
reduced; the pachytene stage was impaired most severely. Expression of cell proliferation-associated genes was reduced in Gmnnfl/Δ; Stra8-Cre testes compared to in controls. Increased
DNA damage, decreased Cdt1, and increased phosphorylation of Chk1/Chk2 were observed in Geminin-deficient germ cells. These results suggest that geminin plays important roles in pre-meiotic DNA replication and
subsequent spermatogenesis.
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Affiliation(s)
- Yue Yuan
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100101, China
| | - Xue-Shan Ma
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,The Reproductive Medical Center, the First Affiliated Hospital, Zhengzhou University, Zhengzhou 450052, China
| | - Qiu-Xia Liang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhao-Yang Xu
- The Reproductive Medical Center, the First Affiliated Hospital, Zhengzhou University, Zhengzhou 450052, China
| | - Lin Huang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Tie-Gang Meng
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100101, China
| | - Fei Lin
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Heide Schatten
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
| | - Zhen-Bo Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100101, China
| | - Qing-Yuan Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100101, China
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12
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Zhang R, Real CI, Liu C, Baba HA, Gerken G, Lu M, Broering R. Hepatic expression of oncogenes Bmi1 and Dkk1 is up-regulated in hepatitis B virus surface antigen-transgenic mice and can be induced by treatment with HBV particles or lipopolysaccharides in vitro. Int J Cancer 2017; 141:354-363. [PMID: 28419472 DOI: 10.1002/ijc.30742] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 04/03/2017] [Indexed: 12/25/2022]
Abstract
Previous studies have shown that hepatocellular carcinoma (HCC) develops more frequently in hepatitis B virus surface antigen (HBsAg)-transgenic mice (Alb/HBs) than in wild-type (WT) mice. However, the mechanism of this HCC model has not been well documented. Toll-like receptor 4 (Tlr4) signaling probably links innate immunity and HCC progression. This study was designed to investigate the role of innate immunity in hepatocarcinogenesis in Alb/HBs mice. Immunohistochemical analysis of liver specimens from Alb/HBs mice (16 per group) showed that the oncogenes Bmi1 (16/16, 100%) and Dkk1 (13/16, 81.25%) were highly expressed in Alb/HBs mice, whereas the other oncogenes evaluated were expressed in smaller percentages of mice (Afp, 9/16, 56.2%; Ctnnb1, 5/16, 31.3%; Epcam, 0/16; 0%). Comparable results were obtained by quantitative PCR analysis. Hepatic gene expression of Tlr2, Tlr4, Il6 and Tnf was additionally elevated in Alb/HBs mice. Stimulation of primary murine hepatocytes with cell culture-derived HBV particles or LPS increased the expression of oncogenes (Bmi1, Dkk1) and inflammatory factors (Tnf, Il6, Tlr4). Proliferation and colony formation of hepatoma cells were enhanced by treatment with HBV and LPS and were impaired by the suppression of Bmi1 and Dkk1 by small interfering RNAs. Substantial induction of BMI1 and DKK1 was found in liver biopsy samples from patients with HBV-related HCC but not in HCC samples without HBV infection background. These findings suggest that innate immunity may link inflammation and tumor progression during chronic HBV infection, involving the oncogenes BMI1 and DKK1.
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Affiliation(s)
- Rui Zhang
- Department of Gastroenterology and Hepatology, University Hospital Essen, University Duisburg-Essen, Germany.,Department of Biliary-Pancreatic Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Catherine I Real
- Department of Gastroenterology and Hepatology, University Hospital Essen, University Duisburg-Essen, Germany
| | - Chao Liu
- Department of Biliary-Pancreatic Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Hideo A Baba
- Department of Pathology and Neuropathology, University Hospital Essen, University Duisburg-Essen, Germany
| | - Guido Gerken
- Department of Gastroenterology and Hepatology, University Hospital Essen, University Duisburg-Essen, Germany
| | - Mengji Lu
- Institute of Virology, University Hospital Essen, University Duisburg-Essen, Germany
| | - Ruth Broering
- Department of Gastroenterology and Hepatology, University Hospital Essen, University Duisburg-Essen, Germany
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13
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Li H, Sheng C, Wang S, Yang L, Liang Y, Huang Y, Liu H, Li P, Yang C, Yang X, Jia L, Xie J, Wang L, Hao R, Du X, Xu D, Zhou J, Li M, Sun Y, Tong Y, Li Q, Qiu S, Song H. Removal of Integrated Hepatitis B Virus DNA Using CRISPR-Cas9. Front Cell Infect Microbiol 2017; 7:91. [PMID: 28382278 PMCID: PMC5360708 DOI: 10.3389/fcimb.2017.00091] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/07/2017] [Indexed: 12/12/2022] Open
Abstract
The presence of hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) and the permanent integration of HBV DNA into the host genome confers the risk of viral reactivation and hepatocellular carcinoma. Nucleoside/nucleotide analogs alone have little or no capacity to eliminate replicative HBV templates consisting of cccDNA or integrated HBV DNA. Recently, CRISPR/Cas9 technology has been widely applied as a promising genome-editing tool, and HBV-specific CRISPR-Cas9 systems were shown to effectively mediate HBV cccDNA disruption. However, the integrated HBV DNA fragments are considered as important pro-oncogenic properties and it serves as an important template for viral replication and expression in stable HBV cell line. In this study, we completely excised a full-length 3,175-bp integrated HBV DNA fragment and disrupted HBV cccDNA in a stable HBV cell line. In HBV-excised cell line, the HBV cccDNA inside cells, supernatant HBV DNA, HBsAg, and HBeAg remained below the negative critical values for more than 10 months. Besides, by whole genome sequencing, we analyzed off-target effects and excluded cell contamination. It is the first time that the HBV infection has been fully eradicated in a stable HBV cell line. These findings demonstrate that the CRISPR-Cas9 system is a potentially powerful tool capable of promoting a radical or “sterile” HBV cure.
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Affiliation(s)
- Hao Li
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Chunyu Sheng
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Shan Wang
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Lang Yang
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Yuan Liang
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Yong Huang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology Beijing, China
| | - Hongbo Liu
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Peng Li
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Chaojie Yang
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Xiaoxia Yang
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Leili Jia
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Jing Xie
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Ligui Wang
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Rongzhang Hao
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Xinying Du
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Dongping Xu
- Research Centre for Liver Failure, Beijing 302nd Hospital Beijing, China
| | - Jianjun Zhou
- Research Center for Translational Medicine, Cancer Stem Cell Institute, East Hospital, Tongji University School of MedicineShanghai, China; Gladcan Consulting CompanyBeijing, China
| | - Mingzhen Li
- Research and Development Department, Beijing Center for Physical and Chemical Analysis Beijing, China
| | - Yansong Sun
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Yigang Tong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology Beijing, China
| | - Qiao Li
- Department of Surgery, University of Michigan Ann Arbor, MI, USA
| | - Shaofu Qiu
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
| | - Hongbin Song
- Center for Infectious Disease Control, Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China
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14
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Kushwaha PP, Rapalli KC, Kumar S. Geminin a multi task protein involved in cancer pathophysiology and developmental process: A review. Biochimie 2016; 131:115-127. [PMID: 27702582 DOI: 10.1016/j.biochi.2016.09.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 09/29/2016] [Indexed: 02/05/2023]
Abstract
DNA replicates in a timely manner with each cell division. Multiple proteins and factors are involved in the initiation of DNA replication including a dynamic interaction between Cdc10-dependent transcript (Cdt1) and Geminin (GMNN). A conformational change between GMNN-Cdt1 heterotrimer and heterohexamer complex is responsible for licensing or inhibition of the DNA replication. This molecular switch ensures a faithful DNA replication during each S phase of cell cycle. GMNN inhibits Cdt1-mediated minichromosome maintenance helicases (MCM) loading onto the chromatin-bound origin recognition complex (ORC) which results in the inhibition of pre-replication complex assembly. GMNN modulates DNA replication by direct binding to Cdt1, and thereby alters its stability and activity. GMNN is involved in various stages of development such as pre-implantation, germ layer formation, cell commitment and specification, maintenance of genome integrity at mid blastula transition, epithelial to mesenchymal transition during gastrulation, neural development, organogenesis and axis patterning. GMNN interacts with different proteins resulting in enhanced hematopoietic stem cell activity thereby activating the development-associated genes' transcription. GMNN expression is also associated with cancer pathophysiology and development. In this review we discussed the structure and function of GMNN in detail. Inhibitors of GMNN and their role in DNA replication, repair, cell cycle and apoptosis are reviewed. Further, we also discussed the role of GMNN in virus infected host cells.
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Affiliation(s)
- Prem Prakash Kushwaha
- School of Basic and Applied Sciences, Centre for Biochemistry and Microbial Sciences, Central University of Punjab, Bathinda, 151001, India
| | - Krishna Chaitanya Rapalli
- School of Basic and Applied Sciences, Centre for Animal Sciences, Central University of Punjab, Bathinda, 151001, India
| | - Shashank Kumar
- School of Basic and Applied Sciences, Centre for Biochemistry and Microbial Sciences, Central University of Punjab, Bathinda, 151001, India.
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15
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Yin Y, Rothenberg E. Probing the Spatial Organization of Molecular Complexes Using Triple-Pair-Correlation. Sci Rep 2016; 6:30819. [PMID: 27545293 PMCID: PMC4992864 DOI: 10.1038/srep30819] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 07/08/2016] [Indexed: 11/25/2022] Open
Abstract
Super-resolution microscopy coupled with multiplexing techniques can resolve specific spatial arrangements of different components within molecular complexes. However, reliable quantification and analysis of such specific organization is extremely problematic because it is frequently obstructed by random co-localization incidents between crowded molecular species and the intrinsic heterogeneity of molecular complexes. To address this, we present a Triple-Pair-Correlation (TPC) analysis approach for unbiased interpretation of the spatial organization of molecular assemblies in crowded three-color super-resolution (SR) images. We validate this approach using simulated data, as well as SR images of DNA replication foci in human cells. This demonstrates the applicability of TPC in deciphering the specific spatial organization of molecular complexes hidden in dense multi-color super-resolution images.
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Affiliation(s)
- Yandong Yin
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, 550 1st Avenue, New York, NY 10016, USA
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, 550 1st Avenue, New York, NY 10016, USA
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16
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Karavias D, Maroulis I, Papadaki H, Gogos C, Kakkos S, Karavias D, Bravou V. Overexpression of CDT1 Is a Predictor of Poor Survival in Patients with Hepatocellular Carcinoma. J Gastrointest Surg 2016; 20:568-79. [PMID: 26408331 DOI: 10.1007/s11605-015-2960-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 09/16/2015] [Indexed: 01/31/2023]
Abstract
BACKGROUND Genomic instability is a common feature in hepatocellular carcinoma. Deregulation of replication licensing factors has been shown to trigger DNA damage response contributing to genomic instability. Overexpression of DNA replication licensing factors chromatin licensing and DNA replication factor 1 (CDT1) and minichromosome maintenance complex component 7 (MCM7) has been previously reported in several human cancers. The aim of the present study was to evaluate the expression and prognostic significance of CDT1 and MCM7 in association with DNA damage response markers and p53 in patients with hepatocellular carcinoma. METHODS Expression of CDT1, MCM7, p-H2A histone family member X (H2AX), phospho-ataxia telangiectasia-mutated (ATM)/ataxia telangiectasia rad3-related (ATR) substrate, and p53 was evaluated by immunohistochemistry on formalin-fixed paraffin-embedded surgical specimens from 111 patients who underwent hepatectomy for hepatocellular carcinoma. Statistical analysis was performed to evaluate associations between the studied proteins, clinicopathological parameters, and patient survival. RESULTS CDT1 expression correlated with p-H2AX (p = 0.038), while MCM7 correlated with p-H2AX and phospho-ATM/ATR substrate (p < 0.001). Increased CDT1 expression was associated with higher tumor grade (p = 0.006) and tumor-node-metastasis (TNM) stage (p = 0.033). High CDT1 expression correlated significantly with reduced overall survival (60.8 and 26.5 % vs 82.8 and 53.0 %, for low CDT1 expression, at 2 and 5 years, respectively, p = 0.012) and was identified by multivariate analysis as an independent predictor of poor overall survival (p = 0.049). CONCLUSIONS Overexpression of CDT1 and MCM7 in hepatocellular carcinoma correlates with DNA damage response, and CDT1 overexpression is a significant prognostic biomarker in hepatocellular carcinoma.
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Affiliation(s)
- Dimitrios Karavias
- Department of Surgery, University Hospital of Patras, Rio, 26500, Greece.
| | - Ioannis Maroulis
- Department of Surgery, University Hospital of Patras, Rio, 26500, Greece
| | - Helen Papadaki
- Department of Anatomy, Histology and Embryology, School of Medicine, University of Patras, Rio, Greece
| | - Charalambos Gogos
- Department of Internal Medicine, University Hospital of Patras, Rio, Greece
| | - Stavros Kakkos
- Department of Vascular Surgery, University Hospital of Patras, Rio, Greece
| | | | - Vasiliki Bravou
- Department of Anatomy, Histology and Embryology, School of Medicine, University of Patras, Rio, Greece
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17
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Li YW, Yang FC, Lu HQ, Zhang JS. Hepatocellular carcinoma and hepatitis B surface protein. World J Gastroenterol 2016; 22:1943-1952. [PMID: 26877602 PMCID: PMC4726670 DOI: 10.3748/wjg.v22.i6.1943] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 07/27/2015] [Accepted: 12/01/2015] [Indexed: 02/06/2023] Open
Abstract
The tumorigenesis of hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) has been widely studied. HBV envelope proteins are important for the structure and life cycle of HBV, and these proteins are useful for judging the natural disease course and guiding treatment. Truncated and mutated preS/S are produced by integrated viral sequences that are defective for replication. The preS/S mutants are considered “precursor lesions” of HCC. Different preS/S mutants induce various mechanisms of tumorigenesis, such as transactivation of transcription factors and an immune inflammatory response, thereby contributing to HCC. The preS2 mutants and type II “Ground Glass” hepatocytes represent novel biomarkers of HBV-associated HCC. The preS mutants may induce the unfolded protein response and endoplasmic reticulum stress-dependent and stress-independent pathways. Treatments to inhibit hepatitis B surface antigen (HBsAg) and damage secondary to HBsAg or the preS/S mutants include antivirals and antioxidants, such as silymarin, resveratrol, and glycyrrhizin acid. Methods for the prevention and treatment of HCC should be comprehensive.
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18
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Ma XS, Lin F, Wang ZW, Hu MW, Huang L, Meng TG, Jiang ZZ, Schatten H, Wang ZB, Sun QY. Geminin deletion in mouse oocytes results in impaired embryo development and reduced fertility. Mol Biol Cell 2016; 27:768-75. [PMID: 26764091 PMCID: PMC4803303 DOI: 10.1091/mbc.e15-06-0346] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 01/06/2016] [Indexed: 12/28/2022] Open
Abstract
Geminin is an important regulator of DNA replication and cell differentiation, but its role in female reproduction remains uncertain. Maternal geminin does not regulate oocyte meiotic maturation but does control accurate DNA replication. Geminin deletion in oocytes results in impaired embryo development and reduced fertility. Geminin controls proper centrosome duplication, cell division, and differentiation. We investigated the function of geminin in oogenesis, fertilization, and early embryo development by deleting the geminin gene in oocytes from the primordial follicle stage. Oocyte-specific disruption of geminin results in low fertility in mice. Even though there was no evident anomaly of oogenesis, oocyte meiotic maturation, natural ovulation, or fertilization, early embryo development and implantation were impaired. The fertilized eggs derived from mutant mice showed developmental delay, and many were blocked at the late zygote stage. Cdt1 protein was decreased, whereas Chk1 and H2AX phosphorylation was increased, in fertilized eggs after geminin depletion. Our results suggest that disruption of maternal geminin may decrease Cdt1 expression and cause DNA rereplication, which then activates the cell cycle checkpoint and DNA damage repair and thus impairs early embryo development.
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Affiliation(s)
- Xue-Shan Ma
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Fei Lin
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhong-Wei Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Meng-Wen Hu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China University of Chinese Academy of Sciences, Beijing 100101, China
| | - Lin Huang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Tie-Gang Meng
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China University of Chinese Academy of Sciences, Beijing 100101, China
| | - Zong-Zhe Jiang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Heide Schatten
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211
| | - Zhen-Bo Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qing-Yuan Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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19
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Petrova NV, Velichko AK, Razin SV, Kantidze OL. Early S-phase cell hypersensitivity to heat stress. Cell Cycle 2015; 15:337-44. [PMID: 26689112 DOI: 10.1080/15384101.2015.1127477] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Heat stress is one of the best-studied exogenous stress factors; however little is known about its delayed effects. Recently, we have shown that heat stress induces cellular senescence-like G2 arrest exclusively in early S-phase cells. The mechanism of this arrest includes the generation of heat stress-induced single-stranded DNA breaks, the collision of replication forks with these breaks and the formation of difficult-to-repair double-stranded DNA breaks. However, the early S phase-specific effects of heat stress are not limited to the induction of single-stranded DNA breaks. Here, we report that HS induces partial DNA re-replication and centrosome amplification. We suggest that HS-induced alterations in the expression levels of the genes encoding the replication licensing factors are the primary source of such perturbations. Notably, these processes do not contribute to acquisition of a senescence-like phenotype, although they do elicit postponed effects. Specifically, we found that the HeLa cells can escape from the heat stress-induced cellular senescence-like G2 arrest, and the mitosis they enter is multipolar due to the amplified centrosomes.
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Affiliation(s)
- Nadezhda V Petrova
- a Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia
| | - Artem K Velichko
- a Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia
| | - Sergey V Razin
- a Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia.,b Department of Molecular Biology , Lomonosov Moscow State University , Moscow , Russia.,c LIA 1066 French-Russian Joint Cancer Research Laboratory , Villejuif , France
| | - Omar L Kantidze
- a Institute of Gene Biology, Russian Academy of Sciences , Moscow , Russia.,b Department of Molecular Biology , Lomonosov Moscow State University , Moscow , Russia.,c LIA 1066 French-Russian Joint Cancer Research Laboratory , Villejuif , France
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20
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Nagahashi M, Matsuda Y, Moro K, Tsuchida J, Soma D, Hirose Y, Kobayashi T, Kosugi SI, Takabe K, Komatsu M, Wakai T. DNA damage response and sphingolipid signaling in liver diseases. Surg Today 2015; 46:995-1005. [PMID: 26514817 DOI: 10.1007/s00595-015-1270-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 10/04/2015] [Indexed: 02/06/2023]
Abstract
Patients with unresectable hepatocellular carcinoma (HCC) cannot generally be cured by systemic chemotherapy or radiotherapy due to their poor response to conventional therapeutic agents. The development of novel and efficient targeted therapies to increase their treatment options depends on the elucidation of the molecular mechanisms that underlie the pathogenesis of HCC. The DNA damage response (DDR) is a network of cell-signaling events that are triggered by DNA damage. Its dysregulation is thought to be one of the key mechanisms underlying the generation of HCC. Sphingosine-1-phosphate (S1P), a lipid mediator, has emerged as an important signaling molecule that has been found to be involved in many cellular functions. In the liver, the alteration of S1P signaling potentially affects the DDR pathways. In this review, we explore the role of the DDR in hepatocarcinogenesis of various etiologies, including hepatitis B and C infection and non-alcoholic steatohepatitis. Furthermore, we discuss the metabolism and functions of S1P that may affect the hepatic DDR. The elucidation of the pathogenic role of S1P may create new avenues of research into therapeutic strategies for patients with HCC.
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Affiliation(s)
- Masayuki Nagahashi
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan.
| | - Yasunobu Matsuda
- Department of Medical Technology, Niigata University Graduate School of Health Sciences, 2-746 Asahimachi-dori, Chuo-ku, Niigata, 951-8518, Japan
| | - Kazuki Moro
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Junko Tsuchida
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Daiki Soma
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Yuki Hirose
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Takashi Kobayashi
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Shin-Ichi Kosugi
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Kazuaki Takabe
- Division of Surgical Oncology, Department of Surgery, Virginia Commonwealth University School of Medicine and the Massey Cancer Center, West Hospital 7-402, 1200 East Broad Street, Richmond, VA, 23298-0011, USA
| | - Masaaki Komatsu
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
| | - Toshifumi Wakai
- Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan
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21
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Modulation of DNA damage and repair pathways by human tumour viruses. Viruses 2015; 7:2542-91. [PMID: 26008701 PMCID: PMC4452920 DOI: 10.3390/v7052542] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 05/12/2015] [Indexed: 02/07/2023] Open
Abstract
With between 10% and 15% of human cancers attributable to viral infection, there is great interest, from both a scientific and clinical viewpoint, as to how these pathogens modulate host cell functions. Seven human tumour viruses have been identified as being involved in the development of specific malignancies. It has long been known that the introduction of chromosomal aberrations is a common feature of viral infections. Intensive research over the past two decades has subsequently revealed that viruses specifically interact with cellular mechanisms responsible for the recognition and repair of DNA lesions, collectively known as the DNA damage response (DDR). These interactions can involve activation and deactivation of individual DDR pathways as well as the recruitment of specific proteins to sites of viral replication. Since the DDR has evolved to protect the genome from the accumulation of deleterious mutations, deregulation is inevitably associated with an increased risk of tumour formation. This review summarises the current literature regarding the complex relationship between known human tumour viruses and the DDR and aims to shed light on how these interactions can contribute to genomic instability and ultimately the development of human cancers.
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22
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Hepatitis B virus HBx protein interactions with the ubiquitin proteasome system. Viruses 2014; 6:4683-702. [PMID: 25421893 PMCID: PMC4246244 DOI: 10.3390/v6114683] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 11/16/2014] [Accepted: 11/20/2014] [Indexed: 01/04/2023] Open
Abstract
The hepatitis B virus (HBV) causes acute and chronic hepatitis, and the latter is a major risk factor for the development of hepatocellular carcinoma (HCC). HBV encodes a 17-kDa regulatory protein, HBx, which is required for virus replication. Although the precise contribution(s) of HBx to virus replication is unknown, many viruses target cellular pathways to create an environment favorable for virus replication. The ubiquitin proteasome system (UPS) is a major conserved cellular pathway that controls several critical processes in the cell by regulating the levels of proteins involved in cell cycle, DNA repair, innate immunity, and other processes. We summarize here the interactions of HBx with components of the UPS, including the CUL4 adaptor DDB1, the cullin regulatory complex CSN, and the 26S proteasome. Understanding how these protein interactions benefit virus replication remains a challenge due to limited models in which to study HBV replication. However, studies from other viral systems that similarly target the UPS provide insight into possible strategies used by HBV.
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23
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Ma L, Chua MS, Andrisani O, So S. Epigenetics in hepatocellular carcinoma: An update and future therapy perspectives. World J Gastroenterol 2014; 20:333-345. [PMID: 24574704 PMCID: PMC3923010 DOI: 10.3748/wjg.v20.i2.333] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 01/01/2014] [Accepted: 01/05/2014] [Indexed: 02/06/2023] Open
Abstract
Hepatocellular carcinoma (HCC), the predominant form of adult liver malignancies, is a global health concern. Its dismal prognosis has prompted recent significant advances in the understanding of its etiology and pathogenesis. The deregulation of epigenetic mechanisms, which maintain heritable gene expression changes and chromatin organization, is implicated in the development of multiple cancers, including HCC. This review summarizes the current knowledge of epigenetic mechanisms in the pathogenesis of HCC, with an emphasis on HCC mediated by chronic hepatitis B virus infection. This review also discusses the encouraging outcomes and lessons learnt from epigenetic therapies for hematological and other solid cancers, and highlights the future potential of similar therapies in the treatment of HCC.
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24
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Abstract
The hepatitis B virus (HBV) is a small enveloped DNA virus that causes acute and chronic hepatitis. HBV infection is a world health problem, with 350 million chronically infected people at increased risk of developing liver disease and hepatocellular carcinoma (HCC). HBV has been classified among human tumor viruses by virtue of a robust epidemiologic association between chronic HBV carriage and HCC occurrence. In the absence of cytopathic effect in infected hepatocytes, the oncogenic role of HBV might involve a combination of direct and indirect effects of the virus during the multistep process of liver carcinogenesis. Liver inflammation and hepatocyte proliferation driven by host immune responses are recognized driving forces of liver cell transformation. Genetic and epigenetic alterations can also result from viral DNA integration into host chromosomes and from prolonged expression of viral gene products. Notably, the transcriptional regulatory protein HBx encoded by the X gene is endowed with tumor promoter activity. HBx has pleiotropic activities and plays a major role in HBV pathogenesis and in liver carcinogenesis. Because hepatic tumors carry a dismal prognosis, there is urgent need to develop early diagnostic markers of HCC and effective therapies against chronic hepatitis B. Deciphering the oncogenic mechanisms that underlie HBV-related tumorigenesis might help developing adapted therapeutic strategies.
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Affiliation(s)
- Lise Rivière
- Institut Pasteur, Hepacivirus and Innate Immunity Unit, 28 rue du Dr Roux, 75015, Paris, France,
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Bharadwaj M, Roy G, Dutta K, Misbah M, Husain M, Hussain S. Tackling hepatitis B virus-associated hepatocellular carcinoma--the future is now. Cancer Metastasis Rev 2013; 32:229-68. [PMID: 23114844 DOI: 10.1007/s10555-012-9412-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hepatocellular carcinoma (HCC) is one of the most lethal and prevalent cancers in many developing countries including India. Among the various etiological factors being implicated in the cause of HCC, the most important cause, however, is hepatitis B virus (HBV) infection. Among all HBV genes, HBx is the most critical carcinogenic component, the molecular mechanisms of which have not been completely elucidated. Despite its clinical significance, there exists a very elemental understanding of the molecular, cellular, and environmental mechanisms that drive disease pathogenesis in HCC infected with HBV. Furthermore, there are only limited therapeutic options, the clinical benefits of which are insignificant. Therefore, the quest for novel and effective therapeutic regimen against HBV-related HCC is of paramount importance. This review attempts to epitomize the current state of knowledge of this most common and dreaded liver neoplasm, highlighting the putative treatment avenues and therapeutic research strategies that need to be implemented with immediate effect for tackling HBV-related HCC that has plagued the medical and scientific fraternity for decades. Additionally, this review proposes a novel "five-point" management algorithm for HBV-related HCC apart from portraying the unmet needs, principal challenges, and scientific perspectives that are relevant to controlling this accelerating global health crisis.
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Affiliation(s)
- Mausumi Bharadwaj
- Division of Molecular Genetics & Biochemistry, Institute of Cytology & Preventive Oncology (ICMR), Noida, India.
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Chae S, Ji JH, Kwon SH, Lee HS, Lim JM, Kang D, Lee CW, Cho H. HBxAPα/Rsf-1-mediated HBx-hBubR1 interactions regulate the mitotic spindle checkpoint and chromosome instability. Carcinogenesis 2013; 34:1680-8. [PMID: 23536579 DOI: 10.1093/carcin/bgt105] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Hepatitis B virus (HBV) X protein (HBx), encoded by the HBV genome, is involved in the development of HBV-mediated liver cancer, whose frequency is highly correlated with chromosomal instability (CIN). We reported previously that HBx induces mitotic checkpoint dysfunction by targeting the human serine/threonine kinase BubR1 (hBubR1). However, the underlying mechanism remained unresolved. Here, we show that HBx protein-associated protein α (HBxAPα)/Rsf-1 associates with hBubR1 and HBx in the chromatin fraction during mitosis. Depletion of HBxAPα/Rsf-1 abolished the interaction between HBx and hBubR1, indicating that HBxAPα/Rsf-1 mediates these interactions. Knockdown of HBxAPα/Rsf-1 with small interfering RNA did not affect the recruitment of hBubR1 to kinetochores; however, it did significantly impair HBx targeting to kinetochores. A deletion mutant analysis revealed that two Kunitz domains of HBx, the Cdc20-binding domain of hBubR1 and full-length of HBxAPα/Rsf-1 were essential for these interactions. Thus, binding of HBx to hBubR1, stabilized by HBxAPα/Rsf-1, significantly attenuated hBubR1 binding to Cdc20 and consequently increased the rate of mitotic aberrations. Collectively, our data show that the HBx impairs hBubR1 function and induces CIN through HBxAPα/Rsf-1, providing a novel mechanism for induction of genomic instability by a viral pathogen in hepatocarcinogenesis.
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Affiliation(s)
- Sunyoung Chae
- Department of Biochemistry and Molecular Biology, Ajou University School of Medicine and the Graduate School of Molecular Science and Technology, Ajou University, Suwon, South Korea
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Deregulation of epigenetic mechanisms by the hepatitis B virus X protein in hepatocarcinogenesis. Viruses 2013; 5:858-72. [PMID: 23507839 PMCID: PMC3705300 DOI: 10.3390/v5030858] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/12/2013] [Accepted: 03/13/2013] [Indexed: 12/18/2022] Open
Abstract
This review focuses on the significance of deregulation of epigenetic mechanisms by the hepatitis B virus (HBV) X protein in hepatocarcinogenesis and HBV replication. Epigenetic mechanisms, DNA methylation, and specific histone modifications, e.g., trimethylation of H3 on lysine-27 or lysine-4, maintain ‘cellular memory’ by silencing expression of lineage-inducing factors in stem cells and conversely, of pluripotency factors in differentiated cells. The X protein has been reported to induce expression of DNA methyltransferases (DNMTs), likely promoting epigenetic changes during hepatocarcinogenesis. Furthermore, in cellular and animal models of X-mediated oncogenic transformation, protein levels of chromatin modifying proteins Suz12 and Znf198 are down-regulated. Suz12 is essential for the Polycomb Repressive Complex 2 (PRC2) mediating the repressive trimethylation of H3 on lysine-27 (H3K27me3). Znf198, stabilizes the LSD1-CoREST-HDAC complex that removes, via lysine demethylase1 (LSD1), the activating trimethylation of H3 on lysine-4 (H3K4me3). Down-regulation of Suz12 also occurs in liver tumors of woodchucks chronically infected by woodchuck hepatitis virus, an animal model recapitulating HBV-mediated hepatocarcinogenesis in humans. Significantly, subgroups of HBV-induced liver cancer re-express hepatoblast and fetal markers, and imprinted genes, suggesting hepatocyte reprogramming during oncogenic transformation. Lastly, down-regulation of Suz12 and Znf198 enhances HBV replication. Collectively, these observations suggest deregulation of epigenetic mechanisms by HBV X protein influences both the viral cycle and the host cell.
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Studach LL, Menne S, Cairo S, Buendia MA, Hullinger RL, Lefrançois L, Merle P, Andrisani OM. Subset of Suz12/PRC2 target genes is activated during hepatitis B virus replication and liver carcinogenesis associated with HBV X protein. Hepatology 2012; 56:1240-51. [PMID: 22505317 PMCID: PMC3417088 DOI: 10.1002/hep.25781] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
UNLABELLED Chronic hepatitis B virus (HBV) infection is a major risk factor for developing liver cancer, and the HBV X protein (pX) has been implicated as a cofactor in hepatocyte transformation. We have shown that HBV replication as well as in vitro transformation by pX are associated with induction of the mitotic polo-like kinase 1 (Plk1) and down-regulation of the chromatin remodeling components Suz12 and Znf198. Herein, we demonstrate the same inverse relationship between Plk1 and Suz12/Znf198 in liver tumors from X/c-myc bitransgenic mice and woodchuck hepatitis virus (WHV)-infected woodchucks. Employing these animal models and the HBV replicating HepAD38 cells we examined the effect of Suz12/Znf198 down-regulation on gene expression. Genes analyzed include hepatic cancer stem cell markers BAMBI, DKK1,2, DLK1, EpCAM, MYC, and proliferation genes CCNA1, CCND2, IGFII, MCM4-6, PLK1, RPA2, and TYMS. Suz12 occupancy at the promoters of BAMBI, CCND2, DKK2, DLK1, EpCAM, and IGFII was demonstrated by chromatin immunoprecipitation in untransformed hepatocytes, but was markedly reduced in pX-transformed and Suz12 knockdown cells. Accordingly, we refer to these genes as "Suz12 repressed" genes in untransformed hepatocytes. The Suz12 repressed genes and proliferation genes were induced in HBV-replicating HepAD38 cells and, interestingly, they exhibited distinct expression profiles during hepatocellular carcinoma (HCC) progression in X/c-myc bitransgenics. Specifically, CCND2, EpCAM, and IGFII expression was elevated at the proliferative and preneoplastic stages in X/c-myc bitransgenic livers, whereas BAMBI and PLK1 were overexpressed in hepatic tumors from X/c-myc bitransgenics and WHV-infected woodchucks. Importantly, most of these genes were selectively up-regulated in HBV-induced HCCs. CONCLUSION The distinct expression profile of the identified Suz12 repressed genes in combination with the proliferation genes hold promise as biomarkers for progression of chronic HBV infection to HCC.
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MESH Headings
- Animals
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/virology
- Cell Cycle Proteins/genetics
- Cell Cycle Proteins/metabolism
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/pathology
- Cells, Cultured
- Disease Models, Animal
- Down-Regulation
- Gene Expression Regulation, Viral
- Hepatitis B virus/genetics
- Hepatitis B, Chronic/genetics
- Hepatitis B, Chronic/physiopathology
- Hepatocytes/pathology
- Liver Neoplasms/genetics
- Liver Neoplasms/virology
- Marmota
- Mice
- Mice, Transgenic
- Polycomb Repressive Complex 2/genetics
- Polycomb Repressive Complex 2/metabolism
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Random Allocation
- Sensitivity and Specificity
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Transcriptional Activation
- Viral Regulatory and Accessory Proteins
- Virus Replication/genetics
- Polo-Like Kinase 1
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Affiliation(s)
- Leo L. Studach
- Department of Basic Medical Sciences and Purdue University Center for Cancer Research, West Lafayette, IN, USA
| | - Stephan Menne
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC, USA
| | - Stefano Cairo
- XenTech, Research and Development Department, Genopole Campus 3 Evry, France
| | - Marie Annick Buendia
- Inserm U785 Unit, Hepatobiliary Center, Paul Brousse Hospital, Villejuif, France
| | - Ronald L. Hullinger
- Department of Basic Medical Sciences and Purdue University Center for Cancer Research, West Lafayette, IN, USA
| | - Lydie Lefrançois
- Inserm U1052, Centre de Recherche en Cancérologie de Lyon, Hepatocarcinogenesis and Viral Infection, Lyon Cedex 03 France
| | - Philippe Merle
- Inserm U1052, Centre de Recherche en Cancérologie de Lyon, Hepatocarcinogenesis and Viral Infection, Lyon Cedex 03 France
| | - Ourania M. Andrisani
- Department of Basic Medical Sciences and Purdue University Center for Cancer Research, West Lafayette, IN, USA
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29
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Fallot G, Neuveut C, Buendia MA. Diverse roles of hepatitis B virus in liver cancer. Curr Opin Virol 2012; 2:467-73. [PMID: 22722078 DOI: 10.1016/j.coviro.2012.05.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 05/22/2012] [Accepted: 05/25/2012] [Indexed: 12/19/2022]
Abstract
Hepatitis B virus (HBV) is a widespread human pathogen responsible for acute and chronic liver diseases. The hepatitis B burden is particularly heavy in endemic countries, where liver cirrhosis and hepatocellular carcinoma are leading causes of death. However, the oncogenic role of HBV remains enigmatic. As the virus has no cytopathic effect, liver damage is attributed to immune responses that induce inflammation, apoptosis and regeneration, fostering the accumulation of genetic and epigenetic alterations. In a more direct action, frequent integration of HBV DNA into host chromosomes may lead to insertional mutagenesis of cancer-related genes and chromosomal instability. HBV proteins, notably the HBx transactivator, participate as co-factors in oncogenesis. Better understanding of hepatitis B pathogenesis is mandatory for improving disease management.
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30
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Pandey V, Kumar V. HBx protein of hepatitis B virus promotes reinitiation of DNA replication by regulating expression and intracellular stability of replication licensing factor CDC6. J Biol Chem 2012; 287:20545-54. [PMID: 22523071 DOI: 10.1074/jbc.m112.359760] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Prevention of re-replication via negative regulation of replication initiator proteins, such as CDC6, is key to maintenance of genomic integrity, whereas their up-regulation is generally associated with perturbation in cell cycle, genomic instability, and potentially, tumorigenesis. The HBx oncoprotein of hepatitis B virus is well known to deregulate cell cycle and has been intricately linked to development of hepatocellular carcinoma. Despite a clear understanding of the proliferative effects of HBx on cell cycle, a mechanistic link between HBx-mediated hepatocarcinogenesis and host cell DNA replication remains poorly perused. Here we show that HBx overexpression in both the cellular as well as the transgenic environment resulted in the accumulation of CDC6 through transcriptional and post-translational up-regulation. The HBx-mediated increase in CDK2 activity altered the E2F1-Rb (retinoblastoma) balance, which favored CDC6 gene expression by E2F1. Besides, HBx impaired the APC(Cdh1)-dependent protein degradation pathway and conferred intracellular stability to CDC6 protein. Increase in CDC6 levels correlated with increase in CDC6 occupancy on the β-globin origin of replication, suggesting increment in origin licensing and re-replication. In conclusion, our findings strongly suggest a novel role for CDC6 in abetting the oncogenic sabotage carried out by HBx and support the paradigm that pre-replicative complex proteins have a role in oncogenic transformation.
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Affiliation(s)
- Vijaya Pandey
- Virology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
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31
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Martin-Vilchez S, Lara-Pezzi E, Trapero-Marugán M, Moreno-Otero R, Sanz-Cameno P. The molecular and pathophysiological implications of hepatitis B X antigen in chronic hepatitis B virus infection. Rev Med Virol 2011; 21:315-29. [PMID: 21755567 DOI: 10.1002/rmv.699] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 05/23/2011] [Accepted: 05/26/2011] [Indexed: 12/16/2022]
Abstract
Hepatitis B virus is considered one of the most significant environmental carcinogens in humans. Because the mechanisms of HBV replication and the development of hepatocellular carcinoma (HCC) are partially known, HBV-associated pathogenesis remains a challenge to increase its understanding. Evidence suggests that the regulatory protein hepatitis B virus X (HBx) mediates the establishment and maintenance of the chronic carrier state. HBx is a multifunctional and potentially oncogenic protein that is conserved among mammalian hepadnaviruses; it is produced very early after infection and throughout the chronic phase. HBx exerts its effects by interacting with cellular proteins and activating various signaling pathways. HBx stimulates the transcription of genes that regulate cell growth, apoptosis, and DNA repair. It also interacts with proteasome subunits and affects mitochondrial stability. Moreover, HBx participates in processes that are associated with the progression of chronic liver disease, including angiogenesis and fibrosis. This review discusses the function of HBx in the life cycle of HBV and its contribution to the pathogenesis of HCC.
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Affiliation(s)
- Samuel Martin-Vilchez
- CIBERehd, ISCIII, Madrid, Spain; Servicio Digestivo, Hospital Universitario "La Princesa" and Instituto de Investigación Biomédica "La Princesa", Madrid, Spain
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32
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Nikitin PA, Luftig MA. At a crossroads: human DNA tumor viruses and the host DNA damage response. Future Virol 2011; 6:813-830. [PMID: 21927617 DOI: 10.2217/fvl.11.55] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Human DNA tumor viruses induce host cell proliferation in order to establish the necessary cellular milieu to replicate viral DNA. The consequence of such viral-programmed induction of proliferation coupled with the introduction of foreign replicating DNA structures makes these viruses particularly sensitive to the host DNA damage response machinery. In fact, sensors of DNA damage are often activated and modulated by DNA tumor viruses in both latent and lytic infection. This article focuses on the role of the DNA damage response during the life cycle of human DNA tumor viruses, with a particular emphasis on recent advances in our understanding of the role of the DNA damage response in EBV, Kaposi's sarcoma-associated herpesvirus and human papillomavirus infection.
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Affiliation(s)
- Pavel A Nikitin
- Department of Molecular Genetics & Microbiology, Center for Virology, Duke University Medical Center, Durham, NC, 27708 USA
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33
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Hepatitis C virus and alcohol: same mitotic targets but different signaling pathways. J Hepatol 2011; 54:956-63. [PMID: 21145809 DOI: 10.1016/j.jhep.2010.08.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 07/28/2010] [Accepted: 08/15/2010] [Indexed: 12/27/2022]
Abstract
BACKGROUND & AIMS Chromosomal aberrations are frequently observed in hepatitis C virus (HCV)- and alcohol-related hepatocellular carcinomas (HCCs). The mechanisms by which chromosomal aberrations occur during hepatocarcinogenesis are still unknown. However, these aberrations are considered to be the result of deregulation of some mitotic proteins, including the alteration of Cyclin B1 and Aurora kinase A expression, and the phosphorylation of gamma-tubulin. Our study aims at investigating changes in expression of the above mentioned proteins and related intracellular pathways, in in vitro and in vivo models of both HCV- and alcohol- dependent HCCs. METHODS In this study, the molecular defects and the mechanisms involved in deregulation of the mitotic machinery were analyzed in human hepatoma cells, expressing HCV proteins treated or not with ethanol, and in liver tissues from control subjects (n=10) and patients with HCV- (n=10) or alcohol-related (n=10) HCCs. RESULTS Expression of Cyclin B1, Aurora kinase A, and tyrosine-phosphorylated gamma-tubulin was analyzed in models reproducing HCV infection and ethanol treatment in HCC cells. Interestingly, HCV and alcohol increased the expression of Cyclin B, Aurora kinase A, and tyrosine-phosphorylated gamma-tubulin also in tissues from patients with HCV- or alcohol-related HCCs. In vitro models suggest that HCV requires the expression of PKR (RNA-activated protein kinase), as well as JNK (c-Jun N-terminal kinase) and p38MAPK (p38 mitogen-activated protein kinase) proteins; while, ethanol bypasses all these pathways. CONCLUSIONS Our results support the idea that HCV and alcohol may promote oncogenesis by acting through the same mitotic proteins, but via different signaling pathways.
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34
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Wang WH, Studach LL, Andrisani OM. Proteins ZNF198 and SUZ12 are down-regulated in hepatitis B virus (HBV) X protein-mediated hepatocyte transformation and in HBV replication. Hepatology 2011; 53:1137-47. [PMID: 21480320 PMCID: PMC3079326 DOI: 10.1002/hep.24163] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
UNLABELLED Chronic hepatitis B virus (HBV) infection is a major etiologic factor in hepatocellular carcinoma (HCC) pathogenesis, involving effects of chronic liver inflammation and of the weakly oncogenic HBV X protein (pX). pX-mediated hepatocyte transformation requires Polo-like kinase1 (Plk1) activity, but the mechanism is not fully understood. We identified by a genome-wide short hairpin RNA (shRNA) library screen the genes zinc finger, MYM-type 2 (ZNF198) and suppressor of zeste 12 homolog (Drosophila) (SUZ12) whose protein depletion rescues pX-expressing cells from DNA damage-induced apoptosis. ZNF198 and SUZ12 are components of chromatin remodeling complexes and associate with promyelocytic leukemia (PML) nuclear bodies. Knockdown of ZNF198 and SUZ12 by small interfering RNA (siRNA) reduced p53 stability and DNA repair, rescued pX-expressing hepatocytes from DNA damage-induced apoptosis, and increased pX-induced polyploidy and oncogenic transformation, suggesting ZNF198 and SUZ12 have a role in pX-mediated transformation. Interestingly, during pX-mediated transformation the protein but not messenger RNA (mRNA) levels of ZNF198 and SUZ12 progressively decreased, whereas Plk1 levels increased. Inhibition of Plk1 activity restored protein levels of ZNF198 and SUZ12. In addition, transfected Polo-box-domain (PBD) of Plk1 coimmunoprecipitated with ZNF198 and SUZ12, suggesting that these proteins are Plk1 substrates. Elevated Plk1 and reduced protein levels of ZNF198 and SUZ12 were also observed in human liver cancer cell lines derived from HBV-related tumors and in the presence of HBV replication. Importantly, knockdown by siRNA of ZNF198 and SUZ12 enhanced HBV replication. CONCLUSION Reduced protein levels of ZNF198 and SUZ12 and elevated Plk1 occur during pX-mediated hepatocyte transformation in human liver cancer cell lines, as well as during HBV replication, underscoring the significance of these genes both in HBV-mediated HCC pathogenesis and HBV replication. We propose Plk1 activity down-regulates ZNF198 and SUZ12, thereby enhancing both HBV replication and pX-mediated oncogenic transformation.
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Affiliation(s)
| | | | - Ourania M. Andrisani
- Department of Basic Medical Sciences and Purdue University Center for Cancer Research, West Lafayette, IN, USA
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35
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Andrisani OM, Studach L, Merle P. Gene signatures in hepatocellular carcinoma (HCC). Semin Cancer Biol 2011; 21:4-9. [PMID: 20851183 PMCID: PMC3030925 DOI: 10.1016/j.semcancer.2010.09.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 09/08/2010] [Accepted: 09/13/2010] [Indexed: 12/25/2022]
Abstract
Primary hepatocellular carcinoma (HCC) is a significant human cancer globally, with poor prognosis. New and efficacious therapy strategies are needed as well as new biomarkers for early detection of at-risk patients. In this review, we discuss select microarray studies of human HCCs, and propose a gene signature that has promise for clinical/translational application. This gene signature combines the proliferation cluster of genes and the hepatic cancer initiating/stem cell gene cluster for identification of HCCs with poor prognosis. Evidence from cell-based assays identifies the existence of a mechanistic link between these two gene clusters, involving the proliferation cluster gene polo-like kinase 1 (PLK1). We propose that PLK1 is a promising therapy target for HCC.
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Affiliation(s)
- Ourania M Andrisani
- Basic Medical Sciences Department and Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, United States.
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36
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Gong Q, He S. Advances in understanding the biological roles of HBx. Shijie Huaren Xiaohua Zazhi 2010; 18:3656-3661. [DOI: 10.11569/wcjd.v18.i34.3656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B virus (HBV) is the leading cause of liver cancer. Globally, there are over 350 million individuals chronically infected with HBV, and approximately 25% of these individuals will develop hepatocellular carcinoma (HCC). HBV is the prototype virus of the hepadnavirus family. The genome of HBV is circular and contains four open reading frames (ORFs). The HBx protein encoded by the X region of HBV is a multifunctional regulatory protein that possesses a wide transactivation activity and plays critical roles in regulating intracellular signal transduction, viral replication and transcription, cell proliferation and apoptosis, protein degradation, and heredity stability of hepatocytes. Due to its important roles in the development of chronic liver diseases, the research on the HBx protein has become a hot topic in recent years. In this paper, we will summarize the latest advances in understanding the biological roles of the HBx protein.
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37
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Studach L, Wang WH, Weber G, Tang J, Hullinger RL, Malbrue R, Liu X, Andrisani O. Polo-like kinase 1 activated by the hepatitis B virus X protein attenuates both the DNA damage checkpoint and DNA repair resulting in partial polyploidy. J Biol Chem 2010; 285:30282-93. [PMID: 20624918 PMCID: PMC2943266 DOI: 10.1074/jbc.m109.093963] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 07/09/2010] [Indexed: 01/21/2023] Open
Abstract
Hepatitis B virus X protein (pX), implicated in hepatocarcinogenesis, induces DNA damage because of re-replication and allows propagation of damaged DNA, resulting in partial polyploidy and oncogenic transformation. The mechanism by which pX allows cells with DNA damage to continue proliferating is unknown. Herein, we show pX activates Polo-like kinase 1 (Plk1) in the G(2) phase, thereby attenuating the DNA damage checkpoint. Specifically, in the G(2) phase of pX-expressing cells, the checkpoint kinase Chk1 was inactive despite DNA damage, and protein levels of claspin, an adaptor of ataxia telangiectasia-mutated and Rad3-related protein-mediated Chk1 phosphorylation, were reduced. Pharmacologic inhibition or knockdown of Plk1 restored claspin protein levels, Chk1 activation, and p53 stabilization. Also, protein levels of DNA repair protein Mre11 were decreased in the G(2) phase of pX-expressing cells but not with Plk1 knockdown. Interestingly, in pX-expressing cells, Mre11 co-immunoprecipitated with transfected Plk1 Polo-box domain, and inhibition of Plk1 increased Mre11 stability in cycloheximide-treated cells. These results suggest that pX-activated Plk1 by down-regulating Mre11 attenuates DNA repair. Importantly, concurrent inhibition of Plk1, p53, and Mre11 increased the number of pX-expressing cells with DNA damage entering mitosis, relative to Plk1 inhibition alone. By contrast, inhibition or knockdown of Plk1 reduced pX-induced polyploidy while increasing apoptosis. We conclude Plk1, activated by pX, allows propagation of DNA damage by concurrently attenuating the DNA damage checkpoint and DNA repair, resulting in polyploidy. We propose this novel Plk1 mechanism initiates pX-mediated hepatocyte transformation.
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Affiliation(s)
- Leo Studach
- From the Departments of Basic Medical Sciences and
| | | | - Gregory Weber
- Biochemistry, Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907
| | - Jiabin Tang
- Biochemistry, Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907
| | | | | | - Xiaoqi Liu
- Biochemistry, Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907
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38
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Li G, Park HU, Liang D, Zhao RY. Cell cycle G2/M arrest through an S phase-dependent mechanism by HIV-1 viral protein R. Retrovirology 2010; 7:59. [PMID: 20609246 PMCID: PMC2909154 DOI: 10.1186/1742-4690-7-59] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2010] [Accepted: 07/07/2010] [Indexed: 01/23/2023] Open
Abstract
Background Cell cycle G2 arrest induced by HIV-1 Vpr is thought to benefit viral proliferation by providing an optimized cellular environment for viral replication and by skipping host immune responses. Even though Vpr-induced G2 arrest has been studied extensively, how Vpr triggers G2 arrest remains elusive. Results To examine this initiation event, we measured the Vpr effect over a single cell cycle. We found that even though Vpr stops the cell cycle at the G2/M phase, but the initiation event actually occurs in the S phase of the cell cycle. Specifically, Vpr triggers activation of Chk1 through Ser345 phosphorylation in an S phase-dependent manner. The S phase-dependent requirement of Chk1-Ser345 phosphorylation by Vpr was confirmed by siRNA gene silencing and site-directed mutagenesis. Moreover, downregulation of DNA replication licensing factors Cdt1 by siRNA significantly reduced Vpr-induced Chk1-Ser345 phosphorylation and G2 arrest. Even though hydroxyurea (HU) and ultraviolet light (UV) also induce Chk1-Ser345 phosphorylation in S phase under the same conditions, neither HU nor UV-treated cells were able to pass through S phase, whereas vpr-expressing cells completed S phase and stopped at the G2/M boundary. Furthermore, unlike HU/UV, Vpr promotes Chk1- and proteasome-mediated protein degradations of Cdc25B/C for G2 induction; in contrast, Vpr had little or no effect on Cdc25A protein degradation normally mediated by HU/UV. Conclusions These data suggest that Vpr induces cell cycle G2 arrest through a unique molecular mechanism that regulates host cell cycle regulation in an S-phase dependent fashion.
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Affiliation(s)
- Ge Li
- Department of Pathology, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
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Wei Y, Neuveut C, Tiollais P, Buendia MA. Molecular biology of the hepatitis B virus and role of the X gene. ACTA ACUST UNITED AC 2010; 58:267-72. [PMID: 20483545 DOI: 10.1016/j.patbio.2010.03.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 03/05/2010] [Indexed: 12/16/2022]
Abstract
The hepatitis B virus (HBV) is a widespread human pathogen and a major health problem in many countries. Molecular cloning and sequencing of the viral DNA genome has demonstrated a small and compact structure organized into four overlapping reading frames that encode the viral proteins. Besides structural proteins of the core and the envelope, HBV encodes a DNA polymerase with reverse transcriptase activity, a secreted antigen of unknown function, and a transcriptional activator that is essential for viral replication. Major steps of the viral life cycle have been unraveled, including transcription of all viral RNAs from nuclear covalently closed circular DNA (cccDNA), followed by encapsidation of pregenomic RNA, a more-than-genome length transcript, and reverse transcription of pregenomic RNA leading to asymmetric synthesis of the DNA strands. Although HBV has been recognized as a human tumor virus, no direct transforming activity could be evidenced in different cellular and animal models. However, the transcriptional regulatory protein HBx encoded by the X gene is endowed with weak oncogenic activity. HBx harbors pleiotropic activities and plays a major role in HBV pathogenesis and in liver carcinogenesis.
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Affiliation(s)
- Y Wei
- Unité oncogenèse et virologie moléculaire, département de virologie, Institut Pasteur, 28, rue du Dr-Roux, 75724 Paris cedex 15, France
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40
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Neuveut C, Wei Y, Buendia MA. Mechanisms of HBV-related hepatocarcinogenesis. J Hepatol 2010; 52:594-604. [PMID: 20185200 DOI: 10.1016/j.jhep.2009.10.033] [Citation(s) in RCA: 322] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 10/22/2009] [Accepted: 10/23/2009] [Indexed: 12/04/2022]
Abstract
The hepatitis B virus (HBV) is a small enveloped DNA virus, which primarily infects hepatocytes and causes acute and persistent liver disease. Epidemiological studies have provided overwhelming evidence for a causal role of chronic HBV infection in the development of hepatocellular carcinoma, but the molecular mechanisms underlying virally-induced tumourigenesis remain largely debated. In the absence of a dominant oncogene encoded by the HBV genome, indirect roles have been proposed, including insertional activation of cellular cancer-related genes by HBV DNA integration, induction of genetic instability by viral integration or by the regulatory protein HBx, and long-term effects of viral proteins in enhancing immune-mediated liver disease. Recent genetic studies indicate that HBV-related tumours display a distinctive profile with a high rate of chromosomal alterations and low frequency of beta-catenin mutations. This review will discuss the evidence implicating chronic HBV infection as a causal risk factor of primary liver cancer. It will also discuss the molecular mechanisms that are critical for the tumourigenic process due to long lasting infection with HBV.
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Affiliation(s)
- Christine Neuveut
- Oncogenesis and Molecular Virology Unit, Institut Pasteur, Inserm U579, 28 rue du Dr Roux, Paris cedex 15, France
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41
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Li C, Jin J. DNA replication licensing control and rereplication prevention. Protein Cell 2010; 1:227-36. [PMID: 21203969 DOI: 10.1007/s13238-010-0032-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Accepted: 01/18/2010] [Indexed: 01/23/2023] Open
Abstract
Eukaryotic DNA replication is tightly restricted to only once per cell cycle in order to maintain genome stability. Cells use multiple mechanisms to control the assembly of the prereplication complex (pre-RC), a process known as replication licensing. This review focuses on the regulation of replication licensing by posttranslational modifications of the licensing factors, including phosphorylation, ubiquitylation and acetylation. These modifications are critical in establishing the pre-RC complexes as well as preventing rereplication in each cell cycle. The relationship between rereplication and diseases, including cancer and virus infection, is discussed as well.
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Affiliation(s)
- Chonghua Li
- Department of Biochemistry and Molecular Biology, The University of Texas Medical School at Houston, Houston, TX 77030, USA
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42
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Liver cell transformation in chronic HBV infection. Viruses 2009; 1:630-646. [PMID: 21994562 PMCID: PMC3185520 DOI: 10.3390/v1030630] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Revised: 10/26/2009] [Accepted: 10/29/2009] [Indexed: 12/20/2022] Open
Abstract
Epidemiological studies have provided overwhelming evidence for a causal role of chronic HBV infection in the development of hepatocellular carcinoma (HCC), but the molecular mechanisms underlying virally-induced tumorigenesis remain largely debated. In the absence of a dominant oncogene encoded by the HBV genome, indirect roles have been proposed, including insertional activation of cellular oncogenes by HBV DNA integration, induction of genetic instability by viral integration or by the regulatory protein HBx, and long term effects of viral proteins in enhancing immune-mediated liver disease. In this chapter, we discuss different models of HBV-mediated liver cell transformation based on animal systems of hepadnavirus infection as well as functional studies in hepatocyte and hepatoma cell lines. These studies might help identifying the cellular effectors connecting HBV infection and liver cell transformation.
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Matsuda Y, Ichida T. Impact of hepatitis B virus X protein on the DNA damage response during hepatocarcinogenesis. Med Mol Morphol 2009; 42:138-42. [PMID: 19784739 DOI: 10.1007/s00795-009-0457-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Accepted: 06/04/2009] [Indexed: 12/24/2022]
Abstract
Hepatocellular carcinoma (HCC) is one of the most prevalent and lethal cancers worldwide. The main HCC-associated diseases are chronic infections with hepatitis B virus (HBV) and hepatitis C virus (HCV), and HBV-associated HCC is still prevalent in Asia. Many studies have suggested that HBV X protein (HBX), which is the most common ORF integrated into the host genome, plays a crucial role in hepatocarcinogenesis. However, the accumulated evidence regarding HBX-mediated signaling pathways is not concordant, and it is difficult to understand the mechanistic nature of HBX-associated hepatocarcinogenesis. For example, HBX was reported to inactivate the early responses to DNA damage via p53-dependent and -independent pathways by interacting with several DNA damage-binding proteins and was also reported to sensitize cells to p53-mediated apoptosis via ataxia-telangiectasia and Rad3-related (ATR)-dependent signaling. HBX also interferes with the centrosome replication process, resulting in rearrangement of chromosomes with micronuclei. Moreover, HBX was found to sensitize protein kinases such as Ras/Raf/mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK), stress-activated protein kinase/NH2-terminal-Jun kinase (SAPK/JNK), protein kinase B (PKB/Akt), and Janus kinase/STAT (JAK/STAT), indicating that a variety of signaling pathways may be activated by HBX. In this review, we focus on the roles of HBX in DNA damage repair during HCC development, with a view to achieving a better understanding of the significance of HBX in the early steps of hepatocarcinogenesis.
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Affiliation(s)
- Yasunobu Matsuda
- Department of Medical Technology, Niigata University Graduate School of Health Sciences, Niigata, 951-8518, Japan.
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Studach LL, Rakotomalala L, Wang WH, Hullinger RL, Cairo S, Buendia MA, Andrisani OM. Polo-like kinase 1 inhibition suppresses hepatitis B virus X protein-induced transformation in an in vitro model of liver cancer progression. Hepatology 2009; 50:414-23. [PMID: 19472310 PMCID: PMC2788305 DOI: 10.1002/hep.22996] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
UNLABELLED Chronic hepatitis B virus (HBV) infection is linked to development of hepatocellular carcinoma (HCC). The HBV X protein (pX) is implicated in HCC pathogenesis acting as a weak oncogene or a cofactor in hepatocarcinogenesis. pX induces DNA re-replication, DNA damage, and partial polyploidy in a poorly differentiated, immortalized hepatocyte cell line. In this study we employed sorted, pX-induced polyploid cells to investigate their growth and oncogenic transformation potential over the course of 70 cell doublings. Immediately after live cell-sorting, nearly 40% of pX-induced polyploid cells undergo apoptosis, whereas the surviving cells exhibit proliferation sensitive to p53. After 40 cell generations the pX-expressing polyploid cultures exhibit loss of p53 function and become growth factor- and anchorage-independent, indicative of oncogenic transformation. The pX-induced polyploid cultures in the course of 70 cell generations undergo progressively increasing DNA damage, propagate damaged DNA to daughter cells, and display increased expression of a cluster of proliferation genes shown to be elevated in human HCC, including HBV-HCC. One of these genes is the mitotic kinase Polo-like kinase 1 (Plk1). Oncogenic transformation is suppressed in the absence of pX expression, and significantly, by inhibition of Plk1. These results identify Plk1 as crucial in pX-mediated oncogenic transformation. CONCLUSION Partial polyploidy induced by pX is not immediately associated with oncogenic transformation. Continued DNA damage for 40 cell generations is reproducibly associated with loss of p53 function, enhanced expression of Plk1, and oncogenic transformation. Because Plk1 expression is also elevated in HBV-HCC tumors, this in vitro cellular model simulates liver cancer progression and pathogenesis in chronic HBV patients. Inhibition of Plk1 activity suppresses pX-mediated oncogenic transformation, identifying Plk1 as a promising therapeutic target for HBV-mediated HCC.
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Affiliation(s)
- Leo L. Studach
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, USA
| | - Lova Rakotomalala
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, USA
| | - Wen-Horng Wang
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, USA
| | - Ronald L. Hullinger
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, USA
| | - Stefano Cairo
- Oncogenesis and Molecular Virology Unit, Institut Pasteur, Paris Cedex 15, France
| | - Marie-Annick Buendia
- Oncogenesis and Molecular Virology Unit, Institut Pasteur, Paris Cedex 15, France
| | - Ourania M. Andrisani
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, USA
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Chaurushiya MS, Weitzman MD. Viral manipulation of DNA repair and cell cycle checkpoints. DNA Repair (Amst) 2009; 8:1166-76. [PMID: 19473887 DOI: 10.1016/j.dnarep.2009.04.016] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Recognition and repair of DNA damage is critical for maintaining genomic integrity and suppressing tumorigenesis. In eukaryotic cells, the sensing and repair of DNA damage are coordinated with cell cycle progression and checkpoints, in order to prevent the propagation of damaged DNA. The carefully maintained cellular response to DNA damage is challenged by viruses, which produce a large amount of exogenous DNA during infection. Viruses also express proteins that perturb cellular DNA repair and cell cycle pathways, promoting tumorigenesis in their quest for cellular domination. This review presents an overview of strategies employed by viruses to manipulate DNA damage responses and cell cycle checkpoints as they commandeer the cell to maximize their own viral replication. Studies of viruses have identified key cellular regulators and revealed insights into molecular mechanisms governing DNA repair, cell cycle checkpoints, and transformation.
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Affiliation(s)
- Mira S Chaurushiya
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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