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Kar A, Mukherjee S, Mukherjee S, Biswas A. Ubiquitin: A double-edged sword in hepatitis B virus-induced hepatocellular carcinoma. Virology 2024; 599:110199. [PMID: 39116646 DOI: 10.1016/j.virol.2024.110199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 07/26/2024] [Accepted: 07/31/2024] [Indexed: 08/10/2024]
Abstract
Hepatitis B virus is one of the leading causes behind the neoplastic transformation of liver tissue and associated mortality. Despite the availability of many therapies and vaccines, the pathogenic landscape of the virus remains elusive; urging the development of novel strategies based on the fundamental infectious and transformative modalities of the virus-host interactome. Ubiquitination is a widely observed post-translational modification of several proteins, which either regulates the proteins' turnover or impacts their functionalities. In recent years, ample amount of literature has accumulated regarding the ubiquitination dynamics of the HBV proteins as well as the host proteins during HBV infection and carcinogenesis; with direct and detailed characterization of the involvement of HBV in these processes. Interestingly, while many of these ubiquitination events restrict HBV life cycle and carcinogenesis, several others promote the emergence of hepatocarcinoma by putting the virus in an advantageous position. This review sums up the snowballing literature on ubiquitination-mediated regulation of the host-HBV crosstalk, with special emphasis on its influence on the establishment and progression of hepatocellular carcinoma on a molecular level. With the advent of cutting-edge ubiquitination-targeted therapeutic approaches, the findings emanating from this review may potentiate the identification of novel anti-HBV targets for the formulation of novel anticancer strategies to control the HBV-induced hepato-carcinogenic process on a global scale.
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Affiliation(s)
- Arpita Kar
- Department of Signal Transduction & Biogenic Amines, Chittaranjan National Cancer Institute, Kolkata, India
| | - Sandipan Mukherjee
- Department of Signal Transduction & Biogenic Amines, Chittaranjan National Cancer Institute, Kolkata, India
| | - Soumyadeep Mukherjee
- Department of in Vitro Carcinogenesis and Cellular Chemotherapy, Chittaranjan National Cancer Institute, Kolkata, India
| | - Avik Biswas
- Department of Signal Transduction & Biogenic Amines, Chittaranjan National Cancer Institute, Kolkata, India.
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2
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Jose-Abrego A, Roman S, Laguna-Meraz S, Panduro A. Host and HBV Interactions and Their Potential Impact on Clinical Outcomes. Pathogens 2023; 12:1146. [PMID: 37764954 PMCID: PMC10535809 DOI: 10.3390/pathogens12091146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 08/27/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
Hepatitis B virus (HBV) is a challenge for global health services, affecting millions and leading thousands to end-stage liver disease each year. This comprehensive review explores the interactions between HBV and the host, examining their impact on clinical outcomes. HBV infection encompasses a spectrum of severity, ranging from acute hepatitis B to chronic hepatitis B, which can potentially progress to cirrhosis and hepatocellular carcinoma (HCC). Occult hepatitis B infection (OBI), characterized by low HBV DNA levels in hepatitis B surface antigen-negative individuals, can reactivate and cause acute hepatitis B. HBV genotyping has revealed unique geographical patterns and relationships with clinical outcomes. Moreover, single nucleotide polymorphisms (SNPs) within the human host genome have been linked to several clinical outcomes, including cirrhosis, HCC, OBI, hepatitis B reactivation, and spontaneous clearance. The immune response plays a key role in controlling HBV infection by eliminating infected cells and neutralizing HBV in the bloodstream. Furthermore, HBV can modulate host metabolic pathways involved in glucose and lipid metabolism and bile acid absorption, influencing disease progression. HBV clinical outcomes correlate with three levels of viral adaptation. In conclusion, the clinical outcomes of HBV infection could result from complex immune and metabolic interactions between the host and HBV. These outcomes can vary among populations and are influenced by HBV genotypes, host genetics, environmental factors, and lifestyle. Understanding the degrees of HBV adaptation is essential for developing region-specific control and prevention measures.
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Affiliation(s)
- Alexis Jose-Abrego
- Department of Genomic Medicine in Hepatology, Civil Hospital of Guadalajara, “Fray Antonio Alcalde”, Guadalajara 44280, Mexico; (A.J.-A.); (S.R.); (S.L.-M.)
- Health Sciences Center, University of Guadalajara, Guadalajara 44340, Mexico
| | - Sonia Roman
- Department of Genomic Medicine in Hepatology, Civil Hospital of Guadalajara, “Fray Antonio Alcalde”, Guadalajara 44280, Mexico; (A.J.-A.); (S.R.); (S.L.-M.)
- Health Sciences Center, University of Guadalajara, Guadalajara 44340, Mexico
| | - Saul Laguna-Meraz
- Department of Genomic Medicine in Hepatology, Civil Hospital of Guadalajara, “Fray Antonio Alcalde”, Guadalajara 44280, Mexico; (A.J.-A.); (S.R.); (S.L.-M.)
- Health Sciences Center, University of Guadalajara, Guadalajara 44340, Mexico
| | - Arturo Panduro
- Department of Genomic Medicine in Hepatology, Civil Hospital of Guadalajara, “Fray Antonio Alcalde”, Guadalajara 44280, Mexico; (A.J.-A.); (S.R.); (S.L.-M.)
- Health Sciences Center, University of Guadalajara, Guadalajara 44340, Mexico
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3
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Nakaya Y, Nishizawa T, Nishitsuji H, Morita H, Yamagata T, Onomura D, Murata K. TRIM26 positively affects hepatitis B virus replication by inhibiting proteasome-dependent degradation of viral core protein. Sci Rep 2023; 13:13584. [PMID: 37604854 PMCID: PMC10442393 DOI: 10.1038/s41598-023-40688-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 08/16/2023] [Indexed: 08/23/2023] Open
Abstract
Chronic hepatitis B virus (HBV) infection is a major medical concern worldwide. Current treatments for HBV infection effectively inhibit virus replication; however, these treatments cannot cure HBV and novel treatment-strategies should be necessary. In this study, we identified tripartite motif-containing protein 26 (TRIM26) could be a supportive factor for HBV replication. Small interfering RNA-mediated TRIM26 knockdown (KD) modestly attenuated HBV replication in human hepatocytes. Endogenous TRIM26 physically interacted with HBV core protein (HBc), but not polymerase and HBx, through the TRIM26 SPRY domain. Unexpectedly, TRIM26 inhibited HBc ubiquitination even though TRIM26 is an E3 ligase. HBc was degraded by TRIM26 KD in Huh-7 cells, whereas the reduction was restored by a proteasome inhibitor. RING domain-deleted TRIM26 mutant (TRIM26ΔR), a dominant negative form of TRIM26, sequestered TRIM26 from HBc, resulting in promoting HBc degradation. Taking together, this study demonstrated that HBV utilizes TRIM26 to avoid the proteasome-dependent HBc degradation. The interaction between TRIM26 and HBc might be a novel therapeutic target against HBV infection.
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Affiliation(s)
- Yuki Nakaya
- Division of Virology, Department of Infection and Immunity, Jichi Medical University, Shimotsuke, 329-0498, Japan.
| | - Tsutomu Nishizawa
- Division of Virology, Department of Infection and Immunity, Jichi Medical University, Shimotsuke, 329-0498, Japan
| | - Hironori Nishitsuji
- Department of Virology and Parasitology, School of Medicine, Fujita Health University, Toyoake, 470-1192, Japan
| | - Hiromi Morita
- Division of Virology, Department of Infection and Immunity, Jichi Medical University, Shimotsuke, 329-0498, Japan
| | - Tomoko Yamagata
- Division of Virology, Department of Infection and Immunity, Jichi Medical University, Shimotsuke, 329-0498, Japan
| | - Daichi Onomura
- Division of Virology, Department of Infection and Immunity, Jichi Medical University, Shimotsuke, 329-0498, Japan
| | - Kazumoto Murata
- Division of Virology, Department of Infection and Immunity, Jichi Medical University, Shimotsuke, 329-0498, Japan.
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4
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Brezgin SA, Kostyusheva AP, Ponomareva NI, Gegechkori VI, Kirdyashkina NP, Ayvasyan SR, Dmitrieva LN, Kokoreva LN, Chulanov VP, Kostyushev DS. HBx Protein Potentiates Hepatitis B Virus Reactivation. Mol Biol 2022. [DOI: 10.1134/s0026893322050041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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5
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Bari RZA, Nawaz H, Majeed MI, Rashid N, Iqbal M, Akram M, Yaqoob N, Yousaf S, Mushtaq A, Almas F, Shahzadi A, Amin I. Surface-enhanced Raman spectroscopic analysis of centrifugally filtered HBV serum samples. Photodiagnosis Photodyn Ther 2022; 38:102808. [PMID: 35301153 DOI: 10.1016/j.pdpdt.2022.102808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 03/04/2022] [Accepted: 03/10/2022] [Indexed: 12/18/2022]
Abstract
BACKGROUND Raman spectroscopy is an effective tool for detecting and discriminating centrifugally filtered hepatitis B virus serum and centrifugally filtered control serum. OBJECTIVES The purpose of current study is to separate high molecular weight fractions from low molecular weight fractions present hepatitis B serum to increase the disease diagnostic ability of surface enhanced Raman spectroscopy (SERS). METHODS Clinically diagnosed centrifugally filtered serum samples of hepatitis B patients are subjected for surface enhanced Raman spectroscopy (SERS) in comparison with centrifugally filtered serum samples of healthy individuals by using silver nanoparticles (Ag-NPs) as SERS substrates. Some SERS spectral features are solely observed in centrifugally filtered serum samples of hepatitis B and some SERS spectral are solely observed in centrifugally filtered serum samples of healthy individuals. The diagnostic ability of SERS is further enhanced with different statistical techniques like principal component analysis (PCA), partial least square discriminant analysis (PLS-DA) and partial least square regression analysis (PLSR) have applied. RESULTS The disease biomarkers of hepatitis B are more pronounced after their centrifugation as compared with uncentrifuged form. Statistical tools like principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA) clearly differentiated centrifugally filtered serum samples of hepatitis B from centrifugally filtered serum samples of healthy individuals. Furthermore, partial least square regression analysis (PLSR) has been applied for predicting unknown viral load of centrifugally filtered serum sample of hepatitis B. CONCLUSION SERS technique along with chemometric tools have successfully differentiated centrifugally filtered serum samples of hepatitis B from centrifugally filtered serum samples of healthy individuals. The centrifugal filtration process has increased the differentiation accuracy of PLS-DA in terms of percentage 98% and regression accuracy of PLSR regression analysis in terms of RMSEP (0.30 IU/mL) of this diagnostic method as compared with that of uncentrifuged method.
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Affiliation(s)
- Rana Zaki Abdul Bari
- Department of Chemistry, University of Agriculture Faisalabad, Faisalabad (38000), Pakistan
| | - Haq Nawaz
- Department of Chemistry, University of Agriculture Faisalabad, Faisalabad (38000), Pakistan.
| | - Muhammad Irfan Majeed
- Department of Chemistry, University of Agriculture Faisalabad, Faisalabad (38000), Pakistan.
| | - Nosheen Rashid
- Department of Chemistry, University of Education, Faisalabad Campus, Faisalabad (38000), Pakistan.
| | - Maham Iqbal
- Department of Chemistry, University of Agriculture Faisalabad, Faisalabad (38000), Pakistan
| | - Maria Akram
- Department of Chemistry, University of Agriculture Faisalabad, Faisalabad (38000), Pakistan
| | - Nimra Yaqoob
- Department of Chemistry, University of Agriculture Faisalabad, Faisalabad (38000), Pakistan
| | - Sadia Yousaf
- Department of Chemistry, University of Agriculture Faisalabad, Faisalabad (38000), Pakistan
| | - Aqsa Mushtaq
- Department of Chemistry, University of Agriculture Faisalabad, Faisalabad (38000), Pakistan
| | - Farakh Almas
- Department of Chemistry, University of Agriculture Faisalabad, Faisalabad (38000), Pakistan
| | - Anam Shahzadi
- Department of Chemistry, University of Agriculture Faisalabad, Faisalabad (38000), Pakistan
| | - Imran Amin
- PCR Laboratory, PINUM Hospital, Faisalabad (38000), Pakistan
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6
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Lefeuvre C, Le Guillou-Guillemette H, Ducancelle A. A Pleiotropic Role of the Hepatitis B Virus Core Protein in Hepatocarcinogenesis. Int J Mol Sci 2021; 22:ijms222413651. [PMID: 34948447 PMCID: PMC8707456 DOI: 10.3390/ijms222413651] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/18/2021] [Accepted: 12/19/2021] [Indexed: 02/07/2023] Open
Abstract
Chronic hepatitis B virus (HBV) infection is one of the most common factors associated with hepatocellular carcinoma (HCC), which is the sixth most prevalent cancer among all cancers worldwide. However, the pathogenesis of HBV-mediated hepatocarcinogenesis is unclear. Evidence currently available suggests that the HBV core protein (HBc) plays a potential role in the development of HCC, such as the HBV X protein. The core protein, which is the structural component of the viral nucleocapsid, contributes to almost every stage of the HBV life cycle and occupies diverse roles in HBV replication and pathogenesis. Recent studies have shown that HBc was able to disrupt various pathways involved in liver carcinogenesis: the signaling pathways implicated in migration and proliferation of hepatoma cells, apoptosis pathways, and cell metabolic pathways inducing the development of HCC; and the immune system, through the expression and production of proinflammatory cytokines. In addition, HBc can modulate normal functions of hepatocytes through disrupting human host gene expression by binding to promoter regions. This HBV protein also promotes HCC metastasis through epigenetic alterations, such as micro-RNA. This review focuses on the molecular pathogenesis of the HBc protein in HBV-induced HCC.
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Affiliation(s)
- Caroline Lefeuvre
- Laboratoire de Virologie, Département de Biologie des Agents Infectieux, CHU Angers, F-49000 Angers, France; (H.L.G.-G.); (A.D.)
- HIFIH Laboratory UPRES EA3859, SFR ICAT 4208, Angers University, F-49000 Angers, France
- Correspondence:
| | - Hélène Le Guillou-Guillemette
- Laboratoire de Virologie, Département de Biologie des Agents Infectieux, CHU Angers, F-49000 Angers, France; (H.L.G.-G.); (A.D.)
- HIFIH Laboratory UPRES EA3859, SFR ICAT 4208, Angers University, F-49000 Angers, France
| | - Alexandra Ducancelle
- Laboratoire de Virologie, Département de Biologie des Agents Infectieux, CHU Angers, F-49000 Angers, France; (H.L.G.-G.); (A.D.)
- HIFIH Laboratory UPRES EA3859, SFR ICAT 4208, Angers University, F-49000 Angers, France
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7
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Maepa MB, Bloom K, Ely A, Arbuthnot P. Hepatitis B virus: promising drug targets and therapeutic implications. Expert Opin Ther Targets 2021; 25:451-466. [PMID: 33843412 DOI: 10.1080/14728222.2021.1915990] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Introduction: Current therapy for infection with hepatitis B virus (HBV) rarely clears the virus, and viremia commonly resurges following treatment withdrawal. To prevent serious complications of the infection, research has been aimed at identifying new viral and host targets that can be exploited to inactivate HBV replication.Areas covered: This paper reviews the use of these new molecular targets to advance anti-HBV therapy. Emphasis is on appraising data from pre-clinical and early clinical studies described in journal articles published during the past 10 years and available from PubMed.Expert opinion: The wide range of viral and host factors that can be targeted to disable HBV is impressive and improved insight into HBV molecular biology continues to provide the basis for new drug design. In addition to candidate therapies that have direct or indirect actions on HBV covalently closed circular DNA (cccDNA), compounds that inhibit HBsAg secretion, viral entry, destabilize viral RNA and effect enhanced immune responses to HBV show promise. Preclinical and clinical evaluation of drug candidates, as well as investigating use of treatment combinations, are encouraging. The field is poised at an interesting stage and indications are that reliably achieving functional cure from HBV infection is a tangible goal.
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Affiliation(s)
- Mohube Betty Maepa
- School of Pathology, Faculty of Health Sciences, Wits/SAMRC Antiviral Gene Therapy Research Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Kristie Bloom
- School of Pathology, Faculty of Health Sciences, Wits/SAMRC Antiviral Gene Therapy Research Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Abdullah Ely
- School of Pathology, Faculty of Health Sciences, Wits/SAMRC Antiviral Gene Therapy Research Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Patrick Arbuthnot
- School of Pathology, Faculty of Health Sciences, Wits/SAMRC Antiviral Gene Therapy Research Unit, University of the Witwatersrand, Johannesburg, South Africa
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8
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Rajput MK. Mutations and methods of analysis of mutations in Hepatitis B virus. AIMS Microbiol 2020; 6:401-421. [PMID: 33364535 PMCID: PMC7755589 DOI: 10.3934/microbiol.2020024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/23/2020] [Indexed: 12/13/2022] Open
Abstract
Immunization programmes against hepatitis-B are being carried out since more than three decades but still HBV is a major public health problem. Hepatitis B virus (HBV) genome consists of circular and partial double stranded DNA. Due to partial double stranded DNA, it uses an RNA intermediate during replication. This replicative strategy of HBV and lack of polymerase proofreading activity give rise to error occurrences comparable to retroviruses. The low fidelity of polymerase, overlapping reading frames and high replication rate produces many non-identical variants at every cycle of replication. Therefore, HBV spreads with mutations and variations. The mutations have been reported both in non-structural as well as structural genes of HBV genome. Recent advances in molecular biology have made easier to analyse these mutations. Hepatitis B antiviral therapy and immunization are all influenced by genetic variability. The analysis and understanding of these mutations are important for therapy against hepatitis B and updating of diagnostic tools. The present review discusses about mutations occurring in whole HBV genome. The mutation occurring both in structural and non-structural genes and non-coding regions have been described in details. It is much more informative because most of literature available, covers only individual gene or DNA regions of HBV.
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9
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Abdoli A, Nakhaie M, Feizi N, Salimi Jeda A, Ramezani A. Harmonized Autophagy Versus Full-Fledged Hepatitis B Virus: Victorious or Defeated. Viral Immunol 2019; 32:322-334. [PMID: 31483214 DOI: 10.1089/vim.2019.0042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Autophagy is a finely tuned process in the regulation of innate immunity to avoid excessive inflammatory responses and inflammasome signaling. In contrast, the results of recent studies have shown that autophagy may disease-dependently contribute to the pathogenesis of liver diseases, such as fibrosis, cirrhosis, and hepatocellular carcinoma (HCC) during hepatitis B virus (HBV) infection. HBV has learned to subvert the cell's autophagic machinery to promote its replication. Given the great impact of the autophagy mechanism on the HBV infection and HCC, recognizing these factors may be offered new hope for human intervention and treatment of chronic HBV. This review focuses on recent findings viewing the dual role of autophagy plays in the pathogenesis of HBV infected hepatocytes.
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Affiliation(s)
- Asghar Abdoli
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran
| | - Mohsen Nakhaie
- Department of Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Neda Feizi
- Dipartimento di Medicina Interna e Specialità Mediche, Sapienza Università di Roma, Rome, Italy
| | - Ali Salimi Jeda
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Amitis Ramezani
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran
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10
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Mak LY, Wong DKH, Seto WK, Lai CL, Yuen MF. Hepatitis B core protein as a therapeutic target. Expert Opin Ther Targets 2017; 21:1153-1159. [PMID: 29065733 DOI: 10.1080/14728222.2017.1397134] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Lung-Yi Mak
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - Danny Ka-Ho Wong
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
- State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong, China
| | - Wai-Kay Seto
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
- State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong, China
| | - Ching-Lung Lai
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
- State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong, China
| | - Man Fung Yuen
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
- State Key Laboratory for Liver Research, The University of Hong Kong, Hong Kong, China
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11
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He Z, Yu Y, Nong Y, Du L, Liu C, Cao Y, Bai L, Tang H. Hepatitis B virus X protein promotes hepatocellular carcinoma invasion and metastasis via upregulating thioredoxin interacting protein. Oncol Lett 2017; 14:1323-1332. [PMID: 28789347 DOI: 10.3892/ol.2017.6296] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 02/23/2017] [Indexed: 02/05/2023] Open
Abstract
Hepatitis B virus X protein (HBx), a multifunctional protein encoded by the X gene of the hepatitis B virus (HBV) is involved in the metastasis of HBV-associated hepatocellular carcinoma (HCC) through various pathways, including upregulating intracellular reactive oxygen species (ROS). Thioredoxin interacting protein (TXNIP) is a key mediator of intracellular ROS, but its function in HBx-mediated metastasis of HBV-associated HCC is elusive. In the present study, HBV-associated HCC tissues with or without metastasis and HepG2 cells were used to study the function of TXNIP in HBx-mediated metastasis of HBV-associated HCC. Initially, the expression levels of TXNIP and HBx in HBV-associated HCC tissues were detected by immunohistochemistry and reverse transcription-quantitative polymerase chain reaction. The results revealed that high expression of TXNIP may be an independent risk factor for metastasis of HBV-associated HCC, and the mRNA levels of TXNIP and HBx were positively associated. Secondly, the association between HBx and TXNIP was investigated using a HBx expression stable cell line, in which HBx expression was induced and controlled by doxycycline. The results demonstrated that HBx may upregulate TXNIP expression in HepG2 cells. Thirdly, the effects of TXNIP and HBx on HepG2 cell migration and invasion were studied by scratch and Matrigel invasion assays, respectively. The results demonstrated that TXNIP overexpression enhanced HepG2 cell migration and invasion. In addition, ectopic expression of HBx promoted HepG2 cell migration and invasion, and this effect may be attenuated by knockdown of TXNIP expression, which indicated that TXNIP may be involved in the process. In summary, the present results demonstrated that TXNIP may be involved in HBx-mediated metastasis of HBV-associated HCC.
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Affiliation(s)
- Zhiliang He
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.,Division of Infectious Diseases, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, P.R. China
| | - Youjia Yu
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.,Department of Forensic Pathology, Medical School of Basic and Forensic Sciences, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Yunhong Nong
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.,Division of Infectious Diseases, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, P.R. China
| | - Lingyao Du
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.,Division of Infectious Diseases, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, P.R. China
| | - Cong Liu
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.,Division of Infectious Diseases, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, P.R. China
| | - Yong Cao
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.,Department of Forensic Pathology, Medical School of Basic and Forensic Sciences, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Lang Bai
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.,Division of Infectious Diseases, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, P.R. China
| | - Hong Tang
- Center of Infectious Diseases, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.,Division of Infectious Diseases, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, P.R. China
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12
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Su ZJ, Cao JS, Wu YF, Chen WN, Lin X, Wu YL, Lin X. Deubiquitylation of hepatitis B virus X protein (HBx) by ubiquitin-specific peptidase 15 (USP15) increases HBx stability and its transactivation activity. Sci Rep 2017; 7:40246. [PMID: 28074857 PMCID: PMC5225491 DOI: 10.1038/srep40246] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 12/05/2016] [Indexed: 02/07/2023] Open
Abstract
Hepatitis B virus X protein (HBx) plays important roles in viral replication and the development of hepatocellular carcinoma. HBx is a rapid turnover protein and ubiquitin-proteasome pathway has been suggested to influence HBx stability as treatment with proteasome inhibitors increases the levels of HBx protein and causes accumulation of the polyubiquitinated forms of HBx. Deubiquitinases (DUBs) are known to act by removing ubiquitin moieties from proteins and thereby reverse their stability and/or activity. However, no information is available regarding the involvement of DUBs in regulation of ubiquitylation-dependent proteasomal degradation of HBx protein. This study identified the deubiquitylating enzyme USP15 as a critical regulator of HBx protein level. USP15 was found to directly interact with HBx via binding to the HBx region between amino acid residues 51 and 80. USP15 increased HBx protein levels in a dose-dependent manner and siRNA-mediated knockdown of endogenous USP15 reduced HBx protein levels. Increased HBx stability and steady-state level by USP15 were attributable to reduced HBx ubiquitination and proteasomal degradation. Importantly, the transcriptional transactivation function of HBx is enhanced by overexpression of USP15. These results suggest that USP15 plays an essential role in stabilizing HBx and subsequently affects the biological function of HBx.
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Affiliation(s)
- Zhi-Jun Su
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, Fujian Medical University, Fuzhou, China.,Department of Infectious Diseases, The First Hospital of Quanzhou Affiliated to Fujian Medical University, Quanzhou, China
| | - Jia-Shou Cao
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, Fujian Medical University, Fuzhou, China
| | - Yan-Fang Wu
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, Fujian Medical University, Fuzhou, China
| | - Wan-Nan Chen
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, Fujian Medical University, Fuzhou, China
| | - Xinjian Lin
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, Fujian Medical University, Fuzhou, China
| | - Yun-Li Wu
- Fujian Key Laboratory of Tumor Microbiology, Fujian Medical University, Fuzhou, China
| | - Xu Lin
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, Fujian Medical University, Fuzhou, China.,Department of Infectious Diseases, The First Hospital of Quanzhou Affiliated to Fujian Medical University, Quanzhou, China
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Zhao J, Wu J, Cai H, Wang D, Yu L, Zhang WH. E3 Ubiquitin Ligase Siah-1 is Down-regulated and Fails to Target Natural HBx Truncates for Degradation in Hepatocellular Carcinoma. J Cancer 2016; 7:418-26. [PMID: 26918055 PMCID: PMC4749362 DOI: 10.7150/jca.13019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 11/14/2015] [Indexed: 01/05/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is a common worldwide malignancy with high morbidity and mortality. Hepatitis B viral (HBV)-encoded X protein (HBx) and natural HBx variants play important roles in HBV-associated HCC development. HBx is an unstable protein that can be degraded in vivo. Our previous study found that the E3 ubiquitin ligase Siah-1 could target HBx for poly-ubiquitylation and proteasomal degradation and attenuate the transcriptional activity of HBx. However, in HCC patients, high expression levels of HBx and HBx variants are frequently observed and are associated with HCC progression. The mechanism underlying their up-regulation is largely unknown. In this study, we screened for Siah-1 mutations in 270 HCC samples and 9 HCC cell lines, and examined Siah-1 mRNA and protein expression in a subset of paired HCC specimens. Our results demonstrate that Siah-1 is highly conserved, as no somatic mutation was identified, with the exception of one synonymous transition from G to A at codon 67. Both the mRNA and protein levels of Siah-1 were significantly down-regulated in HCC tissues compared with their adjacent normal counterparts. We constructed three natural HBx truncates that were identified in our HCC cases. We found that Siah-1 failed to decrease the stability of these HBx variants and was unable to inhibit the transcriptional activity of these HBx truncates at heat shock elements (HSEs). Moreover, Siah-1 had weaker association with three HBx mutants than full length HBx. Therefore, our findings suggest that down-regulation of Siah-1, but not its mutations, and natural HBx variants resistant to Siah-1-induced degradation may be a novel mechanism for HCC development.
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Affiliation(s)
- Jing Zhao
- 1. Department of General Surgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200040, China
| | - Jing Wu
- 2. Department of Infectious Diseases, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200040, China
| | - Hao Cai
- 3. The State Key Laboratory of Genetics Engineering, Fudan University, Shanghai 200433, China
| | - Dan Wang
- 3. The State Key Laboratory of Genetics Engineering, Fudan University, Shanghai 200433, China
| | - Long Yu
- 3. The State Key Laboratory of Genetics Engineering, Fudan University, Shanghai 200433, China
| | - Wen-Hong Zhang
- 2. Department of Infectious Diseases, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200040, China
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Jiang M, Chen Y, Zhang Y, Chen L, Zhang N, Huang T, Cai YD, Kong X. Identification of hepatocellular carcinoma related genes with k-th shortest paths in a protein-protein interaction network. MOLECULAR BIOSYSTEMS 2014; 9:2720-8. [PMID: 24056857 DOI: 10.1039/c3mb70089e] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Hepatocellular carcinoma (HCC) is the most common type of liver cancer worldwide and one of the deadliest cancers in Asia. But at present, effective targets for HCC clinical therapy are still limited. The "guilt by association" rule suggests that interacting proteins share the same or similar functions and hence may be involved in the same pathway. This assumption can be used to identify disease related genes from protein association networks constructed from existing PPI data. Given the close association between Hepatitis B virus and Hepatitis B which may lead to HCC, here we develop a computational method to identify hepatocellular carcinoma related genes based on k-th shortest paths in the protein-protein interaction (PPI) network (we set k=1, 2 in this study). Finally, we found 33 genes whose p-values were less than 0.05, and most of them have been reported to be involved in HCC tumorigenesis and development. The results also provide a new reference for research into HCC oncogenesis and for development of new strategies for HCC clinical therapies.
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Affiliation(s)
- Min Jiang
- State Key Laboratory of Medical Genomics, Institute of Health Sciences, Shanghai Jiaotong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200025, P.R. China.
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15
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Hong HW, Lee SW, Myung H. Induced degradation of Tat by nucleocapsid (NC) via the proteasome pathway and its effect on HIV transcription. Viruses 2013; 5:1143-52. [PMID: 23611845 PMCID: PMC3705270 DOI: 10.3390/v5041143] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 04/16/2013] [Accepted: 04/16/2013] [Indexed: 11/16/2022] Open
Abstract
Human Immunodeficiency Virus type 1 (HIV-1) is a retrovirus that causes acquired immunodeficiency syndrome (AIDS). HIV-1 Tat protein upregulates transcriptional transactivation. The nucleocapsid protein NC of HIV-1 is a component of virion and plays a key role in genome packaging. Herein, we have demonstrated the interaction between NC and Tat by means of a yeast two-hybrid assay, GST pull-down analysis, co-immunoprecipitation and subcellular colocalization analysis. We observed that the level of Tat was significantly reduced in the presence of NC. But NC did not affect mRNA expression level of Tat. The level of Tat in the presence of NC was increased by treating cells with a proteasome inhibitor, MG132. The ubiquitination state of Tat was not seen to increase in the presence of NC, suggesting the proteasomal degradation was independent of ubiquitination. Lowered level of Tat in the presence of NC led to a decrease in Tat-mediated transcriptional transactivation.
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Affiliation(s)
- Hye-Won Hong
- Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Yong-In, Gyung-Gi Do 449-791, Korea; E-Mail:
| | - Seong-Wook Lee
- Department of Molecular Biology, Institute of Nanosensor and Biotechnology, Dankook University, Yong-In, Gyung-Gi Do 448-701, Korea; E-Mail:
| | - Heejoon Myung
- Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Yong-In, Gyung-Gi Do 449-791, Korea; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +82-31-330-4098; Fax: +82-31-330-4566
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Yang HF, Xue L, Zheng CJ, Yao ZY, Zhang YS, Yao L, Li J. Significance of expression of caspase-3 in chronic hepatitis B and C and nonalcoholic steatohepatitis. Shijie Huaren Xiaohua Zazhi 2012; 20:3701-3706. [DOI: 10.11569/wcjd.v20.i36.3701] [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
AIM: To determine the expression of caspase-3 in liver tissues of patients with chronic hepatitis B (CHB), chronic hepatitis C (CHC), or nonalcoholic steatohepatitis (NASH) and to analyze their clinical and pathological significance.
METHODS: Immunohistochemistry was used to determine the expression of caspase-3 in liver tissues from 70 patients with CHB, 50 patients with CHC, 50 patients with NASH, and 15 normal people.
RESULTS: The positive rates of caspase-3 expression in CHB, CHC and NASH were significantly higher than that in normal hepatic tissue (57.1%, 72.0%, 82.0% vs 18.8%; all P < 0.05). Caspase-3 expression was closely related with hepatic cell apoptosis (r = 0.356, P < 0.001). The positive rates of caspase-3 expression increased with the increase in the degree of pathological injury (all P < 0.05).
CONCLUSION: The expression of caspase-3 in CHB, CHC and NASH is closely related with liver cell apoptosis. Overexpression of caspase-3 may play an important role in the development of hepatitis.
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Guo Y, Kang W, Lei X, Li Y, Xiang A, Liu Y, Zhao J, Zhang J, Yan Z. Hepatitis B viral core protein disrupts human host gene expression by binding to promoter regions. BMC Genomics 2012; 13:563. [PMID: 23088787 PMCID: PMC3484065 DOI: 10.1186/1471-2164-13-563] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 10/15/2012] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The core protein (HBc) of hepatitis B virus (HBV) has been implicated in the malignant transformation of chronically-infected hepatocytes and displays pleiotropic functions, including RNA- and DNA-binding activities. However, the mechanism by which HBc interacts with the human genome to exert effects on hepatocyte function remains unknown. This study investigated the distribution of HBc binding to promoters in the human genome and evaluated its effects on the related genes' expression. RESULTS Whole-genome chromatin immunoprecipitation microarray (ChIP-on-chip) analysis was used to identify HBc-bound human gene promoters. Gene Ontology and pathway analyses were performed on related genes. The quantitative polymerase chain reaction assay was used to verify ChIP-on-chip results. Five novel genes were selected for luciferase reporter assay evaluation to assess the influence of HBc promoter binding. The HBc antibody immunoprecipitated approximately 3100 human gene promoters. Among these, 1993 are associated with known biological processes, and 2208 regulate genes with defined molecular functions. In total, 1286 of the related genes mediate primary metabolic processes, and 1398 encode proteins with binding activity. Sixty-four of the promoters regulate genes related to the mitogen-activated protein kinase (MAPK) pathways, and 41 regulate Wnt/beta-catenin pathway genes. The reporter gene assay indicated that HBc binding up-regulates proto-oncogene tyrosine-protein kinase (SRC), type 1 insulin-like growth factor receptor (IGF1R), and neurotrophic tyrosine kinase receptor 2 (NTRK2), and down-regulates v-Ha-ras Harvey rat sarcoma viral oncogene (HRAS). CONCLUSION HBc has the ability to bind a large number of human gene promoters, and can disrupt normal host gene expression. Manipulation of the transcriptional profile in HBV-infected hepatocytes may represent a key pathogenic mechanism of HBV infection.
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Affiliation(s)
- Yanhai Guo
- State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, School of Pharmacy, Fourth Military Medical University, 169 West Changle Road, Xi’an, 710032, China
| | - Wei Kang
- Department of Clinical Laboratory, Affiliated Hospital of Xi’an Medical University, Xi’an, 710077, China
| | - Xiaoying Lei
- State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, School of Pharmacy, Fourth Military Medical University, 169 West Changle Road, Xi’an, 710032, China
| | - Yongnian Li
- Department of Infectious Diseases, 323 Hospital, Xi’an, 710000, China
| | - An Xiang
- State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, School of Pharmacy, Fourth Military Medical University, 169 West Changle Road, Xi’an, 710032, China
| | - Yonglan Liu
- State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, School of Pharmacy, Fourth Military Medical University, 169 West Changle Road, Xi’an, 710032, China
| | - Jinrong Zhao
- State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, School of Pharmacy, Fourth Military Medical University, 169 West Changle Road, Xi’an, 710032, China
| | - Ju Zhang
- State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, School of Pharmacy, Fourth Military Medical University, 169 West Changle Road, Xi’an, 710032, China
| | - Zhen Yan
- State Key Laboratory of Cancer Biology, Department of Pharmacogenomics, School of Pharmacy, Fourth Military Medical University, 169 West Changle Road, Xi’an, 710032, China
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NIRF, a novel ubiquitin ligase, interacts with hepatitis B virus core protein and promotes its degradation. Biotechnol Lett 2011; 34:29-36. [DOI: 10.1007/s10529-011-0751-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2011] [Accepted: 09/21/2011] [Indexed: 12/29/2022]
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Zhao J, Wang C, Wang J, Yang X, Diao N, Li Q, Wang W, Xian L, Fang Z, Yu L. E3 ubiquitin ligase Siah-1 facilitates poly-ubiquitylation and proteasomal degradation of the hepatitis B viral X protein. FEBS Lett 2011; 585:2943-50. [PMID: 21878328 DOI: 10.1016/j.febslet.2011.08.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2011] [Revised: 07/23/2011] [Accepted: 08/09/2011] [Indexed: 11/15/2022]
Abstract
Hepatitis B viral X protein (HBx) is a multifunctional transactivator and implicated in hepatitis B virus (HBV) replication and hepatocarcinogenesis. HBx can be ubiquitinated and degraded through ubiquitin-proteasome pathway. However, the E3 ubiquitin ligase regulating HBx ubiquitin-dependent degradation is still unknown. In this study, we identified Siah-1 as a novel E3 ubiquitin ligase for HBx, which interacted with HBx and facilitated HBx poly-ubiquitylation and proteasomal degradation. Co-expression of Siah-1 attenuated the transcriptional transactivation of HBx on glucocorticoid response element (GRE), heat shock response element (HSE) and cAMP response element (CRE) signal pathways. Moreover, Siah-1 participated in p53-mediated HBx degradation. Therefore, Siah-1 may play important roles in ubiquitin-dependent degradation of HBx and may be involved in suppressing the progression of hepatocellular carcinoma (HCC).
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Affiliation(s)
- Jing Zhao
- State Key Laboratory of Genetic Engineering, Institute of Genetics, Shanghai, PR China
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20
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Mohamadkhani A, Jazii FR, Poustchi H, Nouraein O, Abbasi S, Sotoudeh M, Montazeri G. The role of mutations in core protein of hepatitis B virus in liver fibrosis. Virol J 2009; 6:209. [PMID: 19939285 PMCID: PMC2800847 DOI: 10.1186/1743-422x-6-209] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Accepted: 11/26/2009] [Indexed: 12/13/2022] Open
Abstract
The core protein of hepatitis B virus encompasses B- and T-cell immunodominant epitopes and subdivided into two domains: the N-terminal and the functional C-terminal consisted phosphorylation sites. Mutations of the core gene may change the conformation of the core protein or cause alteration of important epitopes in the host immune response. In this study twenty nine men (mean age 40 ± 9 years old) with chronic hepatitis B were recruited for direct sequencing of the core gene. Serum ALT and HBV DNA level were measured at the time of liver biopsy. The effects of core protein mutations on patients' characteristics and subsequently mutations in B cell, T helper and cytotoxic T lymphocyte (CTL) epitopes and also C-terminal domain of core protein on the activity of liver disease was evaluated. Liver fibrosis was significantly increased in patients with core protein mutation (1.0 ± 0.8 vs 1.9 ± 1.4 for mean stage of fibrosis P = 0.05). Mutations in CTL epitopes and in phosphorylation sites of C-terminal domain of core protein also were associated with higher liver fibrosis (P = 0.003 and P = 0.04; Fisher's exact test for both). Patients with mutation in C-terminal domain had higher serum ALT (62 ± 17 vs 36 ± 12 IU/l, p = 0.02). Patients with mutations in B cell and T helper epitopes did not show significant difference in the clinical features. Our data suggests that core protein mutations in CTL epitopes and C-terminal domain accompanied with higher stage of liver fibrosis may be due to alterations in the function of core protein.
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21
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p53 Promotes proteasome-dependent degradation of oncogenic protein HBx by transcription of MDM2. Mol Biol Rep 2009; 37:2935-40. [PMID: 19842060 DOI: 10.1007/s11033-009-9855-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 09/28/2009] [Indexed: 12/13/2022]
Abstract
Hepatitis B virus X protein (HBx) is closely involved in the development of hepatocellular carcinoma (HCC). Tumor suppressor p53 was reported to induce HBx degradation and repress its oncogenic function recently, but the molecular mechanism is unknown. In this study, we attempted to identify the underlying mechanism. We found that overexpression of p53 protein reduces the level of HBx protein and shortens its half-life, however, in MDM2 knock out cells, p53 has no effects on degradation of HBx, meanwhile, overexpression of MDM2 in absence of p53 can accelerate turnover of HBx protein. These indicate that p53-mediated HBx degradation is MDM2-dependent. MDM2 interacts with HBx in vitro and in vivo but does not promote its ubiquitination. In consistent with the results above, HCC tissue samples with wild-type p53 hardly detect HBx protein, whereas, HBx always accumulate in the tissues with mutant p53. Our data provide a possible mechanism on how p53 regulate HBx stability and also a new clue for the study of p53 mutation and HCC development.
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22
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Vassilaki N, Mavromara P. The HCV ARFP/F/core+1 protein: production and functional analysis of an unconventional viral product. IUBMB Life 2009; 61:739-52. [PMID: 19548320 DOI: 10.1002/iub.201] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Hepatitis C virus (HCV) is an enveloped positive-strand RNA virus of the Flaviviridae family. It has a genome of about 9,600 nucleotides encoding a large polyprotein (about 3,000 amino acids) that is processed by cellular and viral proteases into at least 10 structural and nonstructural viral proteins. A novel HCV protein has also been identified by our laboratory and others. This protein--known as ARFP (alternative reading frame protein), F (for frameshift) or core+1 (to indicate the position) protein--is synthesized by an open reading frame overlapping the core gene at nucleotide +1 (core+1 ORF). However, almost 10 years after its discovery, we still know little of the biological role of the ARFP/F/core+1 protein. Abolishing core+1 protein production has no affect on HCV replication in cell culture or uPA-SCID mice, suggesting that core+1 protein is probably not important for the HCV reproductive cycle. However, the detection of specific anti-core+1 antibodies and T-cell responses in HCV-infected patients, as reported by many independent laboratories, provides strong evidence that this protein is produced in vivo. Furthermore, analyses of the HCV sequences isolated from patients with hepatocellular carcinoma and in vitro studies have provided strong preliminary evidence to suggest that core+1 protein plays a role in advanced liver disease and liver cancer. The available in vitro data also suggest that certain core function proteins may depend on production of the core+1 protein. We describe here the discovery of the various forms of the core+1 protein and what is currently known about the mechanisms of their production and their biochemical and functional properties. We also provide a detailed summary of the results of patient-based research.
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Affiliation(s)
- Niki Vassilaki
- Molecular Virology Laboratory, Hellenic Pasteur Institute, Athens, Greece.
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23
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24
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Abstract
Hepatitis C virus (HCV) F protein is encoded by the +1 reading frame of the viral genome. It overlaps with the core protein coding sequence, and multiple mechanisms for its expression have been proposed. The full-length F protein that is synthesized by translational ribosomal frameshift at codons 9 to 11 of the core protein sequence is a labile protein. By using a combination of genetic, biochemical, and cell biological approaches, we demonstrate that this HCV F protein can bind to the proteasome subunit protein alpha3, which reduces the F-protein level in cells in a dose-dependent manner. Deletion-mapping analysis identified amino acids 40 to 60 of the F protein as the alpha3-binding domain. This alpha3-binding domain of the F protein together with its upstream sequence could significantly destabilize the green fluorescent protein, an otherwise stable protein. Further analyses using an F-protein mutant lacking lysine and a cell line that contained a temperature-sensitive E1 ubiquitin-activating enzyme indicated that the degradation of the F protein was ubiquitin independent. Based on these observations as well as the observation that the F protein could be degraded directly by the 20S proteasome in vitro, we propose that the full-length HCV F protein as well as the F protein initiating from codon 26 is degraded by an ubiquitin-independent pathway that is mediated by the proteasome subunit alpha3. The ability of the F protein to bind to alpha3 raises the possibility that the HCV F protein may regulate protein degradation in cells.
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25
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Hepatitis B virus core protein inhibits TRAIL-induced apoptosis of hepatocytes by blocking DR5 expression. Cell Death Differ 2008; 16:219-29. [PMID: 18927587 DOI: 10.1038/cdd.2008.144] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Hepatitis B virus (HBV) causes chronic hepatitis in hundreds of millions of people worldwide, which can eventually lead to hepatocellular carcinoma (HCC). The molecular mechanisms underlying HBV persistence are not well understood. TRAIL, the TNF-related apoptosis-inducing ligand, has recently been implicated in hepatocyte death during HBV infection. We report here that the HBV core protein (HBc) is a potent inhibitor of TRAIL-induced apoptosis. Overexpressing HBc significantly decreased TRAIL-induced apoptosis of human hepatoma cells, whereas knocking-down HBc expression in hepatoma cells transfected with HBV genome enhanced it. When present in the same cell, HBc blocked the pro-apoptotic effect of the HBV X protein (HBx). The resistance of HBc-expressing cells to TRAIL-induced apoptosis was associated with a significant reduction in death receptor 5 (DR5) expression. Upon transfection, HBc significantly repressed the promoter activity of the human DR5 gene. Importantly, HBc gene transfer inhibited hepatocyte death in a mouse model of HBV-induced hepatitis; and in patients with chronic hepatitis, DR5 expression in the liver was significantly reduced. These results indicate that HBc may prevent hepatocytes from TRAIL-induced apoptosis by blocking DR5 expression, which in turn contributes to the development of chronic hepatitis and HCC. They also call into question the potential side effects of HBc-based vaccines.
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Ubiquitin-dependent and -independent proteasomal degradation of hepatitis B virus X protein. Biochem Biophys Res Commun 2007; 366:1036-42. [PMID: 18155658 DOI: 10.1016/j.bbrc.2007.12.070] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2007] [Accepted: 12/13/2007] [Indexed: 01/11/2023]
Abstract
The hepatitis B virus X protein (HBX) plays key regulatory roles in viral replication and the development of hepatocellular carcinoma. HBX is an unstable protein; its instability is attributed to rapid degradation through the ubiquitin-proteasome pathway. Here, we show that the middle and carboxyl-terminal domains of HBX, independently fused to GFP, render the recombinant proteins susceptible to proteasomal degradation, while the amino-terminal domain has little effect on the ubiquitination or stability of HBX. Mutation of any single or combination of up to five of six lysine residues, all located in the middle and carboxyl-terminal domain, did not prevent HBX from being ubiquitinated, ruling out any specific lysine as the sole site of ubiquitination. Surprisingly, HBX in which all six lysines were mutated and showed no evidence of ubiquitination, was still susceptible to proteasomal degradation. These results suggest that both ubiquitin-dependent and -independent proteasomal degradation processes are operative in HBX turnover.
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27
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Vassilaki N, Boleti H, Mavromara P. Expression studies of the core+1 protein of the hepatitis C virus 1a in mammalian cells. The influence of the core protein and proteasomes on the intracellular levels of core+1. FEBS J 2007; 274:4057-74. [PMID: 17651444 DOI: 10.1111/j.1742-4658.2007.05929.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Recent studies have suggested the existence of a novel protein of hepatitis C virus (HCV) encoded by an ORF overlapping the core gene in the +1 frame (core+1 ORF). Two alternative translation mechanisms have been proposed for expression of the core+1 ORF of HCV-1a in cultured cells; a frameshift mechanism within codons 8-11, yielding a protein known as core+1/F, and/or translation initiation from internal codons in the core+1 ORF, yielding a shorter protein known as core+1/S. To date, the main evidence for the expression of this protein in vivo has been the specific humoral and cellular immune responses against the protein in HCV-infected patients, inasmuch as its detection in biopsies or the HCV infectious system remains elusive. In this study, we characterized the expression properties of the HCV-1a core+1 protein in mammalian cells in order to identify conditions that facilitate its detection. We showed that core+1/S is a very unstable protein, and that expression of the core protein in addition to proteosome activity can downregulate its intracellular levels. Also, we showed that in the Huh-7/T7 cytoplasmic expression system the core+1 ORF from the HCV-1 isolate supports the synthesis of both the core+1/S and core+1/F proteins. Finally, immunofluorescence and subcellular fractionation analyses indicated that core+1/S and core+1/F are cytoplasmic proteins with partial endoplasmic reticulum distribution in interphase cells, whereas in dividing cells they also localize to the microtubules of the mitotic spindle.
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Affiliation(s)
- Niki Vassilaki
- Molecular Virology Laboratory, Hellenic Pasteur Institute, Athens, Greece
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28
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Id-1 induces proteasome-dependent degradation of the HBX protein. J Mol Biol 2007; 382:34-43. [PMID: 18674781 DOI: 10.1016/j.jmb.2007.06.020] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Revised: 06/06/2007] [Accepted: 06/07/2007] [Indexed: 01/20/2023]
Abstract
Id-1 is a member of the HLH protein family that regulates a wide range of cellular processes such as cell proliferation, apoptosis, senescence and overexpression of Id-1 was recently suggested to play roles in the development and progression of different cancers. Previously, Id-1 was shown to physically interact with the viral protein E1A. Meanwhile, Id-1 expression was found to be regulated by several of the virus-encoded proteins, suggesting that Id-1 may be a common cellular target of the viral proteins. Here, we report that Id-1 interacts with the Hepatitis-B virus (HBV)-encoded protein HBX and regulates its stability in hepatocellular carcinoma (HCC) cells. We found that in HCC cells, ectopic Id-1 expression significantly decreased the half-life of the HBX protein, indicating that HBX is destabilized by Id-1. Meanwhile, the Id-1-induced HBX degradation was found to be inhibited by treatment with proteasome inhibitor, suggesting that this process is mediated through the proteasome pathway. Interestingly, while Id-1 did not induce HBX-ubiquitination, we found that removal of all the lysine residues of the HBX protein protects it from the effect of Id-1, indicating that ubiquitination is still required for the Id-1-mediated HBX degradation. Meanwhile, we found that Id-1 binds to the proteasome subunit C8 and facilitates its interaction with the HBX protein and disruption of this interaction completely abolishes the negative effect of Id-1 on HBX protein stability. Taken together, our results demonstrated a novel function of Id-1 in regulating HBX protein stability through interaction with the proteasome.
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29
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Braun S, Zajakina A, Aleksejeva J, Sharipo A, Bruvere R, Ose V, Pumpens P, Garoff H, Meisel H, Kozlovska T. Proteasomal degradation of core protein variants from chronic hepatitis B patients. J Med Virol 2007; 79:1312-21. [PMID: 17607782 DOI: 10.1002/jmv.20939] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The accumulation of complex hepatitis B virus (HBV) variants with internal in-frame deletions in the C gene in immunosuppressed renal transplant recipients is associated with a severe course of the infection leading to end-stage liver disease (ESLD). A set of six HBV C genes with internal in-frame deletions corresponding to the pattern of HBV population in immunosuppressed patients has been expressed in two different eukaryotic cell lines. Synthesis and proteasomal degradation of HBV core (HBc) protein variants were compared with those of the wild-type HBc. In all cases, the steady-state level of internally deleted HBc proteins, predominantly with longer deletions, were considerably lower and turnover was significantly higher in comparison with those of the wild-type HBc, since all deletion variants were degraded rapidly via the proteasome pathway. Involvement and consequences of the proteasomal degradation machinery in the HBc protein turnover during HBV infection with complex HBV variants in the immunosuppressed patients are discussed.
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Affiliation(s)
- Sabine Braun
- Universitätsmedizin Berlin, Charité, Institut für Virologie, Campus Mitte, Charitéplatz 1, Berlin, Germany
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30
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Yang J, Tugal D, Reiss CS. The role of the proteasome-ubiquitin pathway in regulation of the IFN-gamma mediated anti-VSV response in neurons. J Neuroimmunol 2006; 181:34-45. [PMID: 16959328 PMCID: PMC1764816 DOI: 10.1016/j.jneuroim.2006.07.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2006] [Revised: 06/20/2006] [Accepted: 07/26/2006] [Indexed: 11/21/2022]
Abstract
Pharmacologic inhibition of the proteasome resulted in increased NOS-1 protein levels and increased NO production by neuronal cells. This correlated with an increased antiviral effect of IFN-gamma against the replication of vesicular stomatitis virus (VSV) replication in vitro. We also observed that a regulatory protein, Protein Inhibitor of NOS-1 (PIN) was down-regulated by IFN-gamma treatment, and more ubiquitinated PIN accumulated in IFN-gamma treated neurons. In cells of the reticuloendothelial system, IFN-gamma treatment induces the expression of a set of low molecular weight MHC-encoded proteins (LMPs), which replace the beta-subunit of the proteasome complex during the proteasome neosynthesis, resulting in a complex termed the immunoproteasome. LMP2, -7, and -10 were induced and the immunoproteasome was generated by IFN-gamma treatment in neuronal cells. Importantly, we observed that IFN-gamma induced inhibition of VSV protein synthesis was not dependent on ubiquitination.
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Affiliation(s)
| | | | - Carol Shoshkes Reiss
- Department of Biology and
- Center for Neural Science, New York University, New York, NY 10003
- NYU Cancer Institute and Department of Microbiology, New York University School of Medicine, New York, NY 10016
- Department of Microbiology, Mount Sinai School of Medicine, New York, NY 10029
- Address correspondence and reprint requests to: Dr. Carol Shoshkes Reiss, Biology Department, Silver Center Room 1009, M/s 5181, New York University, 100 Washington Square East, New York, NY 10003-6688. E-mail address:
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Sohn SY, Kim JH, Baek KW, Ryu WS, Ahn BY. Turnover of hepatitis B virus X protein is facilitated by Hdj1, a human Hsp40/DnaJ protein. Biochem Biophys Res Commun 2006; 347:764-8. [PMID: 16842747 DOI: 10.1016/j.bbrc.2006.06.158] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2006] [Accepted: 06/25/2006] [Indexed: 11/27/2022]
Abstract
Hepatitis B virus X (HBX) protein is required for the productive infection of hepatitis B virus (HBV) in vivo and implicated in the development of hepatocellular carcinoma. We have previously shown that hTid-1 and Hdj1, the human Hsp40/DnaJ chaperone proteins, bind the HBV core protein and inhibit viral replication in cell culture system. Here, we report evidences to suggest that HBX is the major target of Hdj1 in the inhibition of HBV replication. Expression of Hdj1 in cultured human hepatoma HepG2 cells facilitated degradation of HBX by the proteasome pathway, and thereby inhibited replication of the wild-type HBV as well as that of the HBX-deficient mutant virus rescued by HBX supplied in trans. Mutational analyses indicated that J domain of Hdj1 is required for the process. These results might provide a molecular basis for the antiviral effect of cellular chaperones.
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Affiliation(s)
- Sook-Young Sohn
- School of Life Sciences and Biotechnology, Korea University, Sungbuk, Seoul, Republic of Korea
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Sohn SY, Kim SB, Kim J, Ahn BY. Negative regulation of hepatitis B virus replication by cellular Hsp40/DnaJ proteins through destabilization of viral core and X proteins. J Gen Virol 2006; 87:1883-1891. [PMID: 16760390 DOI: 10.1099/vir.0.81684-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The hepatitis B virus core protein consists of an amino-terminal capsid-assembly domain and a carboxyl-terminal RNA-binding domain. By using the yeast two-hybrid system, two Hsp40/DnaJ chaperone-family proteins, Hdj1 and hTid1, that interact with the carboxyl-terminal region (aa 94-185) of the core protein were identified. Hdj1 is the prototype member of the family and hTid1 is the human homologue of the Drosophila tumour-suppressor protein Tid56. Binding of the viral core protein with the Hsp40 proteins was confirmed by affinity chromatography and immunoprecipitation of transiently expressed proteins. Moreover, in a sucrose gradient, the precursor form of hTid1 co-sedimented with capsid-like particles composed of the full-length core protein. Unlike the general perception of the role of the cellular chaperone proteins in assisting viral protein folding and thus enhancing virus replication, ectopic expression of Hdj1 and hTid1 suppressed replication of HBV in transfected human hepatoma cells. Conversely, RNA interference-mediated knock-down of hTid1 resulted in increased HBV replication. It was found that both Hsp40 proteins specifically accelerated degradation of the viral core and HBx proteins. Our results suggest that the cellular chaperones, through destabilization of viral proteins, exert inhibitory functions on virus replication and hence may play suppressive roles in hepatocellular carcinoma.
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Affiliation(s)
- Sook-Young Sohn
- School of Life Sciences and Biotechnology, Korea University, Anamdong 5-1, Sungbuk, Seoul 136-701, Korea
| | - Sun-Bum Kim
- School of Life Sciences and Biotechnology, Korea University, Anamdong 5-1, Sungbuk, Seoul 136-701, Korea
| | - Joon Kim
- School of Life Sciences and Biotechnology, Korea University, Anamdong 5-1, Sungbuk, Seoul 136-701, Korea
| | - Byung-Yoon Ahn
- School of Life Sciences and Biotechnology, Korea University, Anamdong 5-1, Sungbuk, Seoul 136-701, Korea
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Kremsdorf D, Soussan P, Paterlini-Brechot P, Brechot C. Hepatitis B virus-related hepatocellular carcinoma: paradigms for viral-related human carcinogenesis. Oncogene 2006; 25:3823-33. [PMID: 16799624 DOI: 10.1038/sj.onc.1209559] [Citation(s) in RCA: 206] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
As discussed in detail in other chapters of this review, chronic hepatitis B (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC). Most HCCs complicate the evolution of an active or inactive cirrhosis. However, some tumors occur on livers with minimal histological changes; the prevalence of such cases varies from one geographical region to the other, being much higher in the southern half of Africa (around 40% of HCCs) than in Asia, America and Europe, where at least 90% of HCCs are associated with the cirrhosis. This heterogeneity is probably a reflection of different environmental and genetic factors. This review will summarize the current knowledge on the mechanisms involved in HBV-related liver carcinogenesis. It will show in particular how viruses can be viewed as tools to discover and dissect new cellular pathways involved in cancer development and emphasize the potential synergistic effects between HBV and hepatitis C virus, as well as between viral infections and other environmental factors, such as alcohol.
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Kalra N, Kumar V. The X protein of hepatitis B virus binds to the F box protein Skp2 and inhibits the ubiquitination and proteasomal degradation of c-Myc. FEBS Lett 2005; 580:431-6. [PMID: 16376880 DOI: 10.1016/j.febslet.2005.12.034] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2005] [Revised: 12/05/2005] [Accepted: 12/10/2005] [Indexed: 12/17/2022]
Abstract
The HBx protein of hepatitis B virus is involved in deregulation of cell cycle and development of hepatocellular carcinoma. Since c-Myc also plays an important role in cell proliferation and tumor development, we studied its regulation by HBx in a human hepatoma cell line. Co-expression of HBx and c-Myc resulted in increased stability of intracellular c-Myc. HBx blocked the ubiquitination of Myc through a direct interaction with the F box region of Skp2 and destabilization of the SCF(Skp2) complex. We suggest that sustained presence of c-Myc combined with mitogenic activity inherent to HBx may be associated with cell cycle deregulation and transformation.
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Affiliation(s)
- Neetu Kalra
- Virology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
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Coombes BK, Valdez Y, Finlay BB. Evasive Maneuvers by Secreted Bacterial Proteins to Avoid Innate Immune Responses. Curr Biol 2004; 14:R856-67. [PMID: 15458668 DOI: 10.1016/j.cub.2004.09.043] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
To cause disease, bacterial pathogens must first breach physical barriers, such as the mucous membrane that lines organs, and then successfully replicate and disseminate while avoiding destruction by the immune system. Many bacterial pathogens accomplish this by secreting proteins into their host environment, which act to subvert or dampen the expanding immune response. Here, we discuss how bacterial pathogens use an arsenal of secreted virulence proteins to modify the outcome of innate immune activation by altering how the immune system recognizes microbial invaders.
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Affiliation(s)
- Brian K Coombes
- Michael Smith Laboratories, University of British Columbia, Vancouver, B.C., V6T 1Z3, Canada
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Song CZ, Wang QW, Song CC, Bai ZL. Viral replication modulated by synthetic peptide derived from hepatitis B virus X protein. World J Gastroenterol 2004; 10:389-92. [PMID: 14760764 PMCID: PMC4724926 DOI: 10.3748/wjg.v10.i3.389] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIM: A strategy for viral vaccine design is the use of conserved peptides to overcome the problem of sequence diversity. At present it is still unclear whether conserved peptide is safe as a candidate vaccine. We reported it here for the first time not only to highlight the biohazard issue and safety importance for viral peptide vaccine, but also to explore the effect of a fully conserved peptide on HBV replication within the carboxyl terminus of HBx.
METHODS: We synthesized the fully conserved peptide (CP) with nine residues, FVLGGCRHK. HBV-producing 2.2.15 cells were treated with or without 3.5 μM CP for 36 hours. Quantitative detection of viral DNA was performed by real-time PCR. HBV antigens were determined by enzyme-linked immunoadsorbent assay (ELISA). Quantitative analyses of p53 and Bax proteins were based on immunofluorescence. Flow cytometry was performed to detect cell cycle and apoptosis.
RESULTS: Both extracellular and intracellular copies of HBV DNA per ml were significantly increased after incubation with 3.5 μM of CP. HBsAg and HBeAg in the cultured medium of CP-treatment cells were as abundant as untreated control cells. CP influenced negatively the extracellular viral gene products, and 3.5 μM CP could significantly inhibit intracellular HBsAg expression. In response to CP, intracellular HBeAg displayed an opposite pattern to that of HBsAg, and 3.5 μM CP could efficiently increase the level of intracellular HBeAg. Flow cytometric analyses exhibited no significant changes on cell cycle, apoptosis, p53 and Bax proteins in 2.2.15 cells with or without CP.
CONCLUSION: Together with the results generated from the synthetic peptide, we address that the conserved region, a domain of HBx, may be responsible for modulating HBV replication. As conserved peptides from infectious microbes are used as immunogens to elicit immune responses, their latent biological hazard for human beings should be evaluated.
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Affiliation(s)
- Chang-Zheng Song
- Laboratory of Immunobiology, College of Life Sciences, Shandong University, Jinan 250100, Shandong Province, China.
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