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Ibrahim IH, Ali OSM, El-Sahar AA, Elrefaei M, El-Sheikh N. Telomerase Expression Related with Poor Immune Response to HCV Core Antigen in Egyptian HCV Patients' PBMCs. J Clin Exp Hepatol 2023; 13:1008-1016. [PMID: 37975051 PMCID: PMC10643511 DOI: 10.1016/j.jceh.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 06/12/2023] [Indexed: 11/19/2023] Open
Abstract
Background Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver. Aim This study aimed to assess serum human telomerase enzyme (hTERT) levels and their relation to the progression of liver disease. Also, it aimed to assess the effect of hepatitis C virus (HCV) core protein on memory T-cells in HCV patients with or without HCC and the correlation between memory cell phenotype and the progression of the disease in the same patients. Methods HTERT level in serum was assessed through relative quantitative RT-PCR. Flow cytometric analysis was used to assess T-cell responsiveness (as IFN- γ secretion) before and after stimulation with HCV core protein and the memory CD8+ cell phenotype using several differentiation markers. Results HTERT was found to be increased in a stepwise manner upon comparing its level in controls, chronic hepatitis patients, cirrhotic patients, and HCC patients. T-cells showed a similar manner of stepwise decrease in response (decreased IFN- γ secretion) in HCC patients compared to HCV patients without HCC and controls. Also, late differentiated memory cells (CD8+, CD27-, CD28-, CD45RA+, and CCR7-) were depleted in HCC patients compared to HCV patients without HCC. Conclusion These results suggest a negative correlation between hTERT and IFN- γ secretion by T-cells in HCV patients and that this relationship, along with the depletion of late differentiated memory cells, could help the progression of liver disease to HCC.
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Affiliation(s)
- Iman H. Ibrahim
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy (Girls), Al-Azhar University, Egypt
| | - Ola Sayed M. Ali
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy (Girls), Al-Azhar University, Egypt
| | - Adel A. El-Sahar
- Department of Tropical Medicine, Faculty of Medicine (Boys), Al-Azhar University, Egypt
| | - Mohamed Elrefaei
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Jacksonville, FL, USA
| | - Nabila El-Sheikh
- Molecular Immunology Unit for Infectious Diseases, Department of Microbiology and Immunology, Faculty of Medicine (Girls), Al-Azhar University, Egypt
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Comparative RNA-Sequencing Analysis Reveals High Complexity and Heterogeneity of Transcriptomic and Immune Profiles in Hepatocellular Carcinoma Tumors of Viral (HBV, HCV) and Non-Viral Etiology. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:medicina58121803. [PMID: 36557005 PMCID: PMC9785216 DOI: 10.3390/medicina58121803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022]
Abstract
Background and Objectives: Hepatocellular carcinoma (HCC), the most common type of primary liver cancer, is the leading cause of cancer-related mortality. It arises and progresses against fibrotic or cirrhotic backgrounds mainly due to infection with hepatitis viruses B (HBV) or C (HCV) or non-viral causes that lead to chronic inflammation and genomic changes. A better understanding of molecular and immune mechanisms in HCC subtypes is needed. Materials and Methods: To identify transcriptional changes in primary HCC tumors with or without hepatitis viral etiology, we analyzed the transcriptomes of 24 patients by next-generation sequencing. Results: We identified common and unique differentially expressed genes for each etiological tumor group and analyzed the expression of SLC, ATP binding cassette, cytochrome 450, cancer testis, and heat shock protein genes. Metascape functional enrichment analysis showed mainly upregulated cell-cycle pathways in HBV and HCV and upregulated cell response to stress in non-viral infection. GeneWalk analysis identified regulator, hub, and moonlighting genes and highlighted CCNB1, ACTN2, BRCA1, IGF1, CDK1, AURKA, AURKB, and TOP2A in the HCV group and HSF1, HSPA1A, HSP90AA1, HSPB1, HSPA5, PTK2, and AURKB in the group without viral infection as hub genes. Immune infiltrate analysis showed that T cell, cytotoxic, and natural killer cell markers were significantly more highly expressed in HCV than in non-viral tumors. Genes associated with monocyte activation had the highest expression levels in HBV, while high expression of genes involved in primary adaptive immune response and complement receptor activity characterized tumors without viral infection. Conclusions: Our comprehensive study underlines the high degree of complexity of immune profiles in the analyzed groups, which adds to the heterogeneous HCC genomic landscape. The biomarkers identified in each HCC group might serve as therapeutic targets.
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Antropova E, Khlebodarova T, Demenkov P, Venzel A, Ivanisenko N, Gavrilenko A, Ivanisenko T, Adamovskaya A, Revva P, Lavrik I, Ivanisenko V. Computer analysis of regulation of hepatocarcinoma marker genes hypermethylated by HCV proteins. Vavilovskii Zhurnal Genet Selektsii 2022; 26:733-742. [PMID: 36714033 PMCID: PMC9840909 DOI: 10.18699/vjgb-22-89] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 11/22/2022] [Accepted: 11/22/2022] [Indexed: 01/07/2023] Open
Abstract
Hepatitis C virus (HCV) is a risk factor that leads to hepatocellular carcinoma (HCC) development. Epigenetic changes are known to play an important role in the molecular genetic mechanisms of virus-induced oncogenesis. Aberrant DNA methylation is a mediator of epigenetic changes that are closely associated with the HCC pathogenesis and considered a biomarker for its early diagnosis. The ANDSystem software package was used to reconstruct and evaluate the statistical significance of the pathways HCV could potentially use to regulate 32 hypermethylated genes in HCC, including both oncosuppressor and protumorigenic ones identified by genome-wide analysis of DNA methylation. The reconstructed pathways included those affecting protein-protein interactions (PPI), gene expression, protein activity, stability, and transport regulations, the expression regulation pathways being statistically significant. It has been shown that 8 out of 10 HCV proteins were involved in these pathways, the HCV NS3 protein being implicated in the largest number of regulatory pathways. NS3 was associated with the regulation of 5 tumor-suppressor genes, which may be the evidence of its central role in HCC pathogenesis. Analysis of the reconstructed pathways has demonstrated that following the transcription factor inhibition caused by binding to viral proteins, the expression of a number of oncosuppressors (WT1, MGMT, SOCS1, P53) was suppressed, while the expression of others (RASF1, RUNX3, WIF1, DAPK1) was activated. Thus, the performed gene-network reconstruction has shown that HCV proteins can influence not only the methylation status of oncosuppressor genes, but also their transcriptional regulation. The results obtained can be used in the search for pharmacological targets to develop new drugs against HCV-induced HCC.
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Affiliation(s)
- E.A. Antropova
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Scences, Novosibirsk, Russia
| | - T.M. Khlebodarova
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Scences, Novosibirsk, RussiaKurchatov Genomic Center of ICG SB RAS, Novosibirsk, Russia
| | - P.S. Demenkov
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Scences, Novosibirsk, RussiaKurchatov Genomic Center of ICG SB RAS, Novosibirsk, Russia
| | - A.S. Venzel
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Scences, Novosibirsk, RussiaKurchatov Genomic Center of ICG SB RAS, Novosibirsk, Russia
| | - N.V. Ivanisenko
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Scences, Novosibirsk, RussiaKurchatov Genomic Center of ICG SB RAS, Novosibirsk, Russia
| | - A.D. Gavrilenko
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Scences, Novosibirsk, RussiaNovosibirsk State University, Novosibirsk, Russia
| | - T.V. Ivanisenko
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Scences, Novosibirsk, RussiaKurchatov Genomic Center of ICG SB RAS, Novosibirsk, Russia
| | - A.V. Adamovskaya
- Kurchatov Genomic Center of ICG SB RAS, Novosibirsk, RussiaNovosibirsk State University, Novosibirsk, Russia
| | - P.M. Revva
- Kurchatov Genomic Center of ICG SB RAS, Novosibirsk, RussiaKurchatov Genomic Center of ICG SB RAS, Novosibirsk, Russia
| | - I.N. Lavrik
- Translational Inflammation Research, Medical Faculty, Otto von Guericke University Magdeburg, Magdeburg, Germany
| | - V.A. Ivanisenko
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Scences, Novosibirsk, RussiaKurchatov Genomic Center of ICG SB RAS, Novosibirsk, RussiaNovosibirsk State University, Novosibirsk, Russia
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Tornesello ML, Cerasuolo A, Starita N, Tornesello AL, Bonelli P, Tuccillo FM, Buonaguro L, Isaguliants MG, Buonaguro FM. The Molecular Interplay between Human Oncoviruses and Telomerase in Cancer Development. Cancers (Basel) 2022; 14:5257. [PMID: 36358677 PMCID: PMC9659228 DOI: 10.3390/cancers14215257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/21/2022] [Accepted: 10/22/2022] [Indexed: 08/29/2023] Open
Abstract
Human oncoviruses are able to subvert telomerase function in cancer cells through multiple strategies. The activity of the catalytic subunit of telomerase (TERT) is universally enhanced in virus-related cancers. Viral oncoproteins, such as high-risk human papillomavirus (HPV) E6, Epstein-Barr virus (EBV) LMP1, Kaposi's sarcoma-associated herpesvirus (HHV-8) LANA, hepatitis B virus (HBV) HBVx, hepatitis C virus (HCV) core protein and human T-cell leukemia virus-1 (HTLV-1) Tax protein, interact with regulatory elements in the infected cells and contribute to the transcriptional activation of TERT gene. Specifically, viral oncoproteins have been shown to bind TERT promoter, to induce post-transcriptional alterations of TERT mRNA and to cause epigenetic modifications, which have important effects on the regulation of telomeric and extra-telomeric functions of the telomerase. Other viruses, such as herpesviruses, operate by integrating their genomes within the telomeres or by inducing alternative lengthening of telomeres (ALT) in non-ALT cells. In this review, we recapitulate on recent findings on virus-telomerase/telomeres interplay and the importance of TERT-related oncogenic pathways activated by cancer-causing viruses.
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Affiliation(s)
- Maria Lina Tornesello
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | - Andrea Cerasuolo
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | - Noemy Starita
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | - Anna Lucia Tornesello
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | - Patrizia Bonelli
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | - Franca Maria Tuccillo
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | - Luigi Buonaguro
- Cancer Immunoregulation Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
| | | | - Franco M. Buonaguro
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Via Mariano Semmola, 80131 Napoli, Italy
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Zhu Z, Tran H, Mathahs MM, Fink BD, Albert JA, Moninger TO, Meier JL, Li M, Schmidt WN. Zinc protoporphyrin binding to telomerase complexes and inhibition of telomerase activity. Pharmacol Res Perspect 2021; 9:e00882. [PMID: 34747573 PMCID: PMC8573827 DOI: 10.1002/prp2.882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 09/23/2021] [Indexed: 12/16/2022] Open
Abstract
Zinc protoporphyrin (ZnPP), a naturally occurring metalloprotoporphyrin (MPP), is currently under development as a chemotherapeutic agent although its mechanism is unclear. When tested against other MPPs, ZnPP was the most effective DNA synthesis and cellular proliferation inhibitor while promoting apoptosis in telomerase positive but not telomerase negative cells. Concurrently, ZnPP down-regulated telomerase expression and was the best overall inhibitor of telomerase activity in intact cells and cellular extracts with IC50 and EC50 values of ca 2.5 and 6 µM, respectively. The natural fluorescence properties of ZnPP enabled direct imaging in cellular fractions using non-denaturing agarose gel electrophoresis, western blots, and confocal fluorescence microscopy. ZnPP localized to large cellular complexes (>600 kD) that contained telomerase and dysskerin as confirmed with immunocomplex mobility shift, immunoprecipitation, and immunoblot analyses. Confocal fluorescence studies showed that ZnPP co-localized with telomerase reverse transcriptase (TERT) and telomeres in the nucleus of synchronized S-phase cells. ZnPP also co-localized with TERT in the perinuclear regions of log phase cells but did not co-localize with telomeres on the ends of metaphase chromosomes, a site known to be devoid of telomerase complexes. Overall, these results suggest that ZnPP does not bind to telomeric sequences per se, but alternatively, interacts with other structural components of the telomerase complex to inhibit telomerase activity. In conclusion, ZnPP actively interferes with telomerase activity in neoplastic cells, thus promoting pro-apoptotic and anti-proliferative properties. These data support further development of natural or synthetic protoporphyrins for use as chemotherapeutic agents to augment current treatment protocols for neoplastic disease.
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Affiliation(s)
- Zhaowen Zhu
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
- Department of Internal MedicineRoy G. and Lucille A. Carver College of MedicineUniversity of IowaIowa CityIowaUSA
| | - Huy Tran
- Department of Internal MedicineRoy G. and Lucille A. Carver College of MedicineUniversity of IowaIowa CityIowaUSA
| | - Meleah M. Mathahs
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
| | - Brian D. Fink
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
| | - John A. Albert
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
| | - Thomas O. Moninger
- Central Microscopy Research Facility Roy G. and Lucille A. Carver College of MedicineUniversity of IowaIowa CityIowaUSA
| | - Jeffery L. Meier
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
- Department of Internal MedicineRoy G. and Lucille A. Carver College of MedicineUniversity of IowaIowa CityIowaUSA
| | - Ming Li
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
| | - Warren N. Schmidt
- Department of Internal Medicine and Research ServiceVeterans Affairs Medical CenterIowa CityIowaUSA
- Department of Internal MedicineRoy G. and Lucille A. Carver College of MedicineUniversity of IowaIowa CityIowaUSA
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6
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Salimi-Jeda A, Badrzadeh F, Esghaei M, Abdoli A. The role of telomerase and viruses interaction in cancer development, and telomerase-dependent therapeutic approaches. Cancer Treat Res Commun 2021; 27:100323. [PMID: 33530025 DOI: 10.1016/j.ctarc.2021.100323] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/19/2021] [Accepted: 01/21/2021] [Indexed: 12/21/2022]
Abstract
Human telomerase reverse transcriptase (hTERT) is an enzyme that is critically involved in elongating and maintaining telomeres length to control cell life span and replicative potential. Telomerase activity is continuously expressed in human germ-line cells and most cancer cells, whereas it is suppressed in most somatic cells. In normal cells, by reducing telomerase activity and progressively shortening the telomeres, the cells progress to the senescence or apoptosis process. However, in cancer cells, telomere lengths remain constant due to telomerase's reactivation, and cells continue to proliferate and inhibit apoptosis, and ultimately lead to cancer development and human death due to metastasis. Studies demonstrated that several DNA and RNA oncoviruses could interact with telomerase by integrating their genome sequence within the host cell telomeres specifically. Through the activation of the hTERT promoter and lengthening the telomere, these cells contributes to cancer development. Since oncoviruses can activate telomerase and increase hTERT expression, there are several therapeutic strategies based on targeting the telomerase of cancer cells like telomerase-targeted peptide vaccines, hTERT-targeting dendritic cells (DCs), hTERT-targeting gene therapy, and hTERT-targeting CRISPR/Cas9 system that can overcome tumor-mediated toleration mechanisms and specifically apoptosis in cancer cells. This study reviews available data on the molecular structure of telomerase and the role of oncoviruses and telomerase interaction in cancer development and telomerase-dependent therapeutic approaches to conquest the cancer cells.
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Affiliation(s)
- Ali Salimi-Jeda
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
| | - Fariba Badrzadeh
- Faculti of Medicine, Golestan University of Medical sciences, Golestan, Iran.
| | - Maryam Esghaei
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
| | - Asghar Abdoli
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran.
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Dash S, Aydin Y, Widmer KE, Nayak L. Hepatocellular Carcinoma Mechanisms Associated with Chronic HCV Infection and the Impact of Direct-Acting Antiviral Treatment. J Hepatocell Carcinoma 2020; 7:45-76. [PMID: 32346535 PMCID: PMC7167284 DOI: 10.2147/jhc.s221187] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 03/06/2020] [Indexed: 12/12/2022] Open
Abstract
Hepatitis C virus (HCV) infection is the major risk factor for liver cirrhosis and hepatocellular carcinoma (HCC). The mechanisms of HCC initiation, growth, and metastasis appear to be highly complex due to the decade-long interactions between the virus, immune system, and overlapping bystander effects of host metabolic liver disease. The lack of a readily accessible animal model system for HCV is a significant obstacle to understand the mechanisms of viral carcinogenesis. Traditionally, the primary prevention strategy of HCC has been to eliminate infection by antiviral therapy. The success of virus elimination by antiviral treatment is determined by the SVR when the HCV is no longer detectable in serum. Interferon-alpha (IFN-α) and its analogs, pegylated IFN-α (PEG-IFN-α) alone with ribavirin (RBV), have been the primary antiviral treatment of HCV for many years with a low cure rate. The cloning and sequencing of HCV have allowed the development of cell culture models, which accelerated antiviral drug discovery. It resulted in the selection of highly effective direct-acting antiviral (DAA)-based combination therapy that now offers incredible success in curing HCV infection in more than 95% of all patients, including those with cirrhosis. However, several emerging recent publications claim that patients who have liver cirrhosis at the time of DAAs treatment face the risk of HCC occurrence and recurrence after viral cure. This remains a substantial challenge while addressing the long-term benefit of antiviral medicine. The host-related mechanisms that drive the risk of HCC in the absence of the virus are unknown. This review describes the multifaceted mechanisms that create a tumorigenic environment during chronic HCV infection. In addition to the potential oncogenic programming that drives HCC after viral clearance by DAAs, the current status of a biomarker development for early prediction of cirrhosis regression and HCC detection post viral treatment is discussed. Since DAAs treatment does not provide full protection against reinfection or viral transmission to other individuals, the recent studies for a vaccine development are also reviewed.
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Affiliation(s)
- Srikanta Dash
- Department of Pathology and Laboratory Medicine, Tulane University Health Sciences Center, New Orleans, LA70112, USA
- Southeast Louisiana Veterans Health Care System, New Orleans, LA70119, USA
- Department of Medicine, Division of Gastroenterology, Tulane University Health Sciences Center, New Orleans, LA70112, USA
| | - Yucel Aydin
- Department of Pathology and Laboratory Medicine, Tulane University Health Sciences Center, New Orleans, LA70112, USA
| | - Kyle E Widmer
- Southeast Louisiana Veterans Health Care System, New Orleans, LA70119, USA
| | - Leela Nayak
- Southeast Louisiana Veterans Health Care System, New Orleans, LA70119, USA
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8
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Abdoli A, Alirezaei M, Mehrbod P, Forouzanfar F. Autophagy: The multi-purpose bridge in viral infections and host cells. Rev Med Virol 2018; 28:e1973. [PMID: 29709097 PMCID: PMC7169200 DOI: 10.1002/rmv.1973] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 02/03/2018] [Accepted: 02/09/2018] [Indexed: 02/06/2023]
Abstract
Autophagy signaling pathway is involved in cellular homeostasis, developmental processes, cellular stress responses, and immune pathways. The aim of this review is to summarize the relationship between autophagy and viruses. It is not possible to be fully comprehensive, or to provide a complete "overview of all viruses". In this review, we will focus on the interaction of autophagy and viruses and survey how human viruses exploit multiple steps in the autophagy pathway to help viral propagation and escape immune response. We discuss the role that macroautophagy plays in cells infected with hepatitis C virus, hepatitis B virus, rotavirus gastroenteritis, immune cells infected with human immunodeficiency virus, and viral respiratory tract infections both influenza virus and coronavirus.
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Affiliation(s)
- Asghar Abdoli
- Department of Hepatitis and AIDSPasteur Institute of IranTehranIran
| | - Mehrdad Alirezaei
- Department of Immunology and Microbial ScienceThe Scripps Research InstituteLa JollaCaliforniaUSA
| | - Parvaneh Mehrbod
- Influenza and Other Respiratory Viruses Dept.Pasteur Institute of IranTehranIran
| | - Faezeh Forouzanfar
- University of Strasbourg, EA7292, DHPIInstitute of Parasitology and Tropical Pathology StrasbourgFrance
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Shiu TY, Shih YL, Feng AC, Lin HH, Huang SM, Huang TY, Hsieh CB, Chang WK, Hsieh TY. HCV core inhibits hepatocellular carcinoma cell replicative senescence through downregulating microRNA-138 expression. J Mol Med (Berl) 2017; 95:629-639. [PMID: 28258280 DOI: 10.1007/s00109-017-1518-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 12/23/2016] [Accepted: 02/07/2017] [Indexed: 01/06/2023]
Abstract
Hepatitis C virus (HCV) infection is a major cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma (HCC). HCV core protein is considered as a positive regulator of telomerase activity. In this study, we focused on the deregulated microRNA-138 (miR-138) in HCV-associated HCC. Differential expression of miR-138 was determined by TaqMan quantitative real-time PCR. The target gene of miR-138 was verified by luciferase reporter assay, quantitative real-time PCR, and Western blotting. Moreover, three assays based on telomerase activity, cell proliferation, and senescence-associated β-galactosidase activity were performed. The correlation analysis revealed a significantly negative correlation between miR-138 and telomerase reverse transcriptase (TERT) mRNA expression in HCC. Further, we showed that mature HCV core protein of 173 amino acids, but not full-length form of 191 amino acids, suppressed miR-138 expression. TERT was verified as a direct target of miR-138 in HCC cells. Furthermore, TERT-targeting miR-138 supplementation can prevent HCV core protein from repressing HCC cell replicative senescence. Collectively, HCV core protein can enhance TERT protein expression through downregulating TERT-targeting miR-138 expression, which in turn inhibits HCC cell replicative senescence. This study may further help our understanding on the pathogenic mechanisms of HCV core protein in HCV-associated HCC development. KEY MESSAGE: miR-138 is downregulated in HCV-associated HCC. Mature HCV core protein plays a pathogenic role in suppressing miR-138 expression. Telomerase reverse transcriptase represents a direct target of miR-138 in HCC cells. miR-138 promotes HCC cell senescence, suggesting potential for HCC treatment.
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Affiliation(s)
- Tzu-Yue Shiu
- Division of Gastroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Lueng Shih
- Division of Gastroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - An-Chieh Feng
- Division of General Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Hsuan-Hwai Lin
- Division of Gastroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Ming Huang
- Department and Graduate Institute of Biochemistry, National Defense Medical Center, Taipei, Taiwan
| | - Tien-Yu Huang
- Division of Gastroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chung-Bao Hsieh
- Division of General Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Wei-Kuo Chang
- Division of Gastroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Tsai-Yuan Hsieh
- Division of Gastroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
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10
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Zhu Z, Tran H, Mathahs MM, Moninger TO, Schmidt WN. HCV Induces Telomerase Reverse Transcriptase, Increases Its Catalytic Activity, and Promotes Caspase Degradation in Infected Human Hepatocytes. PLoS One 2017; 12:e0166853. [PMID: 28056029 PMCID: PMC5215869 DOI: 10.1371/journal.pone.0166853] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 10/17/2016] [Indexed: 01/09/2023] Open
Abstract
Introduction Telomerase repairs the telomeric ends of chromosomes and is active in nearly all malignant cells. Hepatitis C virus (HCV) is known to be oncogenic and potential interactions with the telomerase system require further study. We determined the effects of HCV infection on human telomerase reverse transcriptase (TERT) expression and enzyme activity in primary human hepatocytes and continuous cell lines. Results Primary human hepatocytes and Huh-7.5 hepatoma cells showed early de novo TERT protein expression 2–4 days after infection and these events coincided with increased TERT promoter activation, TERT mRNA, and telomerase activity. Immunoprecipitation studies demonstrated that NS3-4A protease-helicase, in contrast to core or NS5A, specifically bound to the C-terminal region of TERT through interactions between helicase domain 2 and protease sequences. Increased telomerase activity was noted when NS3-4A was transfected into cells, when added to reconstituted mixtures of TERT and telomerase RNA, and when incubated with high molecular weight telomerase ‘holoenzyme’ complexes. The NS3-4A catalytic effect on telomerase was inhibited with primuline or danoprevir, agents that are known to inhibit NS3 helicase and protease activities respectively. In HCV infected cells, NS3-4A could be specifically recovered with telomerase holoenzyme complexes in contrast to NS5A or core protein. HCV infection also activated the effector caspase 7 which is known to target TERT. Activation coincided with the appearance of lower molecular weight carboxy-terminal fragment(s) of TERT, chiefly sized at 45 kD, which could be inhibited with pancaspase or caspase 7 inhibitors. Conclusions HCV infection induces TERT expression and stimulates telomerase activity in addition to triggering Caspase activity that leads to increased TERT degradation. These activities suggest multiple points whereby the virus can influence neoplasia. The NS3-4A protease-helicase can directly bind to TERT, increase telomerase activity, and thus potentially influence telomere repair and host cell neoplastic behavior.
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Affiliation(s)
- Zhaowen Zhu
- Department of Internal Medicine and Research Service, Veterans Affairs Medical Center, Iowa City, IA, United States of America
- Department of Internal Medicine Roy G. and Lucille A. Carver College of Medicine, University of Iowa Iowa City, IA, United States of America
| | - Huy Tran
- Department of Internal Medicine Roy G. and Lucille A. Carver College of Medicine, University of Iowa Iowa City, IA, United States of America
| | - M. Meleah Mathahs
- Department of Internal Medicine and Research Service, Veterans Affairs Medical Center, Iowa City, IA, United States of America
| | - Thomas O. Moninger
- Central Microscopy Research Facility Roy G. and Lucille A. Carver College of Medicine, University of Iowa Iowa City, IA, United States of America
| | - Warren N. Schmidt
- Department of Internal Medicine and Research Service, Veterans Affairs Medical Center, Iowa City, IA, United States of America
- Department of Internal Medicine Roy G. and Lucille A. Carver College of Medicine, University of Iowa Iowa City, IA, United States of America
- * E-mail:
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11
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Hepatocarcinogenesis associated with hepatitis B, delta and C viruses. Curr Opin Virol 2016; 20:1-10. [PMID: 27504999 DOI: 10.1016/j.coviro.2016.07.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 07/20/2016] [Accepted: 07/20/2016] [Indexed: 12/13/2022]
Abstract
Globally, over half a billion people are persistently infected with hepatitis B (HBV) and/or hepatitis C viruses. Chronic HBV and HCV infection frequently lead to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Co-infections with hepatitis delta virus (HDV), a subviral satellite requiring HBV for its propagation, accelerates the progression of liver disease toward HCC. The mechanisms by which these viruses cause malignant transformation, culminating in HCC, remain incompletely understood, partially due to the lack of adequate experimental models for dissecting these complex disease processes in vivo.
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12
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Zanetti M. A second chance for telomerase reverse transcriptase in anticancer immunotherapy. Nat Rev Clin Oncol 2016; 14:115-128. [DOI: 10.1038/nrclinonc.2016.67] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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13
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Mosca E, Alfieri R, Milanesi L. Diffusion of information throughout the host interactome reveals gene expression variations in network proximity to target proteins of hepatitis C virus. PLoS One 2014; 9:e113660. [PMID: 25461596 PMCID: PMC4251971 DOI: 10.1371/journal.pone.0113660] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 10/27/2014] [Indexed: 12/22/2022] Open
Abstract
Hepatitis C virus infection is one of the most common and chronic in the world, and hepatitis associated with HCV infection is a major risk factor for the development of cirrhosis and hepatocellular carcinoma (HCC). The rapidly growing number of viral-host and host protein-protein interactions is enabling more and more reliable network-based analyses of viral infection supported by omics data. The study of molecular interaction networks helps to elucidate the mechanistic pathways linking HCV molecular activities and the host response that modulates the stepwise hepatocarcinogenic process from preneoplastic lesions (cirrhosis and dysplasia) to HCC. Simulating the impact of HCV-host molecular interactions throughout the host protein-protein interaction (PPI) network, we ranked the host proteins in relation to their network proximity to viral targets. We observed that the set of proteins in the neighborhood of HCV targets in the host interactome is enriched in key players of the host response to HCV infection. In opposition to HCV targets, subnetworks of proteins in network proximity to HCV targets are significantly enriched in proteins reported as differentially expressed in preneoplastic and neoplastic liver samples by two independent studies. Using multi-objective optimization, we extracted subnetworks that are simultaneously “guilt-by-association” with HCV proteins and enriched in proteins differentially expressed. These subnetworks contain established, recently proposed and novel candidate proteins for the regulation of the mechanisms of liver cells response to chronic HCV infection.
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Affiliation(s)
- Ettore Mosca
- Institute of Biomedical Technologies, National Research Council, Segrate, Milan, Italy
- * E-mail:
| | - Roberta Alfieri
- Institute of Biomedical Technologies, National Research Council, Segrate, Milan, Italy
| | - Luciano Milanesi
- Institute of Biomedical Technologies, National Research Council, Segrate, Milan, Italy
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14
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Chen X, Kamranvar SA, Masucci MG. Tumor viruses and replicative immortality--avoiding the telomere hurdle. Semin Cancer Biol 2014; 26:43-51. [PMID: 24486644 DOI: 10.1016/j.semcancer.2014.01.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 01/16/2014] [Indexed: 12/26/2022]
Abstract
Tumor viruses promote cell proliferation in order to gain access to an environment suitable for persistence and replication. The expression of viral products that promote growth transformation is often accompanied by the induction of multiple signs of telomere dysfunction, including telomere shortening, damage of telomeric DNA and chromosome instability. Long-term survival and progression to full malignancy require the bypassing of senescence programs that are triggered by the damaged telomeres. Here we review different strategies by which tumor viruses interfere with telomere homeostasis during cell transformation. This frequently involves the activation of telomerase, which assures both the integrity and functionality of telomeres. In addition, recent evidence suggests that oncogenic viruses may activate a recombination-based mechanism for telomere elongation known as Alternative Lengthening of Telomeres (ALT). This error-prone strategy promotes genomic instability and could play an important role in viral oncogenesis.
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Affiliation(s)
- Xinsong Chen
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | | | - Maria G Masucci
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden.
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15
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Basu N, Skinner HG, Litzelman K, Vanderboom R, Baichoo E, Boardman LA. Telomeres and telomere dynamics: relevance to cancers of the GI tract. Expert Rev Gastroenterol Hepatol 2013; 7:733-48. [PMID: 24161135 PMCID: PMC3892561 DOI: 10.1586/17474124.2013.848790] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Aberrations in telomere length and telomere maintenance contribute to cancer development. In this article, we review the basic principles of telomere length in normal and tumor tissue and the presence of the two main telomere maintenance pathways as they pertain to gastrointestinal tract cancer. Peripheral blood telomeres are shorter in patients with many types of gastrointestinal tract cancers. Telomere length in tumor DNA also appears to shorten early in cancer development. Tumor telomere shortening is often accompanied by telomerase activation to protect genetically damaged DNA from normal cell senescence or apoptosis, allowing immortalized but damaged DNA to persist. Alternative lengthening of telomeres is another mechanism used by cancer to maintain telomere length in cancer cells. Telomerase and alternative lengthening of telomeres activators and inhibitors may become important chemopreventive or chemotherapeutic agents as our understanding of telomere biology, specific telomere-related phenotypes and its relationship to carcinogenesis increases.
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Affiliation(s)
- Nivedita Basu
- Division of Gastroenterology and Hepatology Department of Medicine Mayo Clinic 200 First Street SW Rochester, MN 55905 Tel: 507-266-4338; Fax: 507-266-0350
| | - Halcyon G. Skinner
- Department of Population Health Sciences School of Medicine and Public Health University of Wisconsin Madison, WI 53726 Tel: 608-265-4654
| | - Kristin Litzelman
- Department of Population Health Sciences School of Medicine and Public Health University of Wisconsin Madison, WI 53726 Tel: 608-265-4654
| | - Russell Vanderboom
- Division of Gastroenterology and Hepatology Department of Medicine Mayo Clinic 200 First Street SW Rochester, MN 55905 Tel: 507-266-4338; Fax: 507-266-0350
| | - Esha Baichoo
- Division of Gastroenterology and Hepatology Department of Medicine Mayo Clinic 200 First Street SW Rochester, MN 55905 Tel: 507-266-4338; Fax: 507-266-0350
| | - Lisa A. Boardman
- Division of Gastroenterology and Hepatology Department of Medicine Mayo Clinic 200 First Street SW Rochester, MN 55905 Tel: 507-266-4338; Fax: 507-266-0350
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16
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El Idrissi M, Hervieu V, Merle P, Mortreux F, Wattel E. Cause-specific telomere factors deregulation in hepatocellular carcinoma. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2013; 32:64. [PMID: 24020493 PMCID: PMC3850108 DOI: 10.1186/1756-9966-32-64] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 08/22/2013] [Indexed: 12/25/2022]
Abstract
Background Among the numerous genetic defects associated with hepatocarcinogenesis, telomere abnormalities appear to play a role both in tumor promotion and maintenance. Telomeres, the chromosome extremities, are protected by specific proteins, the shelterin complex and by additional factors. Besides telomerase dysregulation, expression changes of these telomere factors have been observed in cancers. Methods Here, we tested the hypothesis that such dysregulation might occur in hepatocellular carcinoma (HCC) with specific patterns depending on the cause of HCC. We compared telomere length, telomerase activity (TA), hTERT and telomere genes expression using PCR and Western-blot analyses between non-cirrhotic liver, peritumoral cirrhotic tissue (40 samples) and cancerous tissue (40 samples) derived from 40 patients with HBV-, HCV-, or alcohol-related HCC. Results Alterations in TA, hTERT expression and telomere length between non-cirrhotic, cirrhotic, and tumor samples were not significantly influenced by the cause of HCC. In contrast, the expression pattern of hTR, shelterin, and non-shelterin telomere protective factors clearly distinguished the 3 causes of cirrhosis and HCC. For patients with HBV diseased liver, when compared with non-cirrhotic liver, the cirrhotic tissue underexpressed all shelterin and all but HMRE11A and RAD50 non-shelterin telomere factors. For HCV the expression level of POT1, RAP1, Ku80, and RAD50 was higher in cirrhotic than in non-cirrhotic liver samples without evidence for significant transcriptional change for the remaining genes. For alcohol-related liver diseases, the expression level of POT1, RAP1, TIN2, hMRE11A, hMRE11B, Ku70, Ku80, RAD50, TANK1, and PINX1 was higher in cirrhotic than in non-cirrhotic liver samples. For the 3 causes of HCC, there was no significant change in shelterin and non-shelterin gene expression between cirrhosis and HCC samples. Conclusions These results validate our hypotheses and demonstrate that cirrhosis and HCC add-up numerous telomere dysfunctions including numerous cause-specific changes that appear to occur early during the course of the disease.
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Affiliation(s)
- Manale El Idrissi
- UMR5239 Oncovirologie et Biothérapies, Faculté de Médecine Lyon Sud, ENS - HCL, Université Lyon 1, CNRS, Pierre Bénite, France.
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17
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Deng Z, Wang Z, Lieberman PM. Telomeres and viruses: common themes of genome maintenance. Front Oncol 2012; 2:201. [PMID: 23293769 PMCID: PMC3533235 DOI: 10.3389/fonc.2012.00201] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 12/08/2012] [Indexed: 12/14/2022] Open
Abstract
Genome maintenance mechanisms actively suppress genetic instability associated with cancer and aging. Some viruses provoke genetic instability by subverting the host's control of genome maintenance. Viruses have their own specialized strategies for genome maintenance, which can mimic and modify host cell processes. Here, we review some of the common features of genome maintenance utilized by viruses and host chromosomes, with a particular focus on terminal repeat (TR) elements. The TRs of cellular chromosomes, better known as telomeres, have well-established roles in cellular chromosome stability. Cellular telomeres are themselves maintained by viral-like mechanisms, including self-propagation by reverse transcription, recombination, and retrotransposition. Viral TR elements, like cellular telomeres, are essential for viral genome stability and propagation. We review the structure and function of viral repeat elements and discuss how they may share telomere-like structures and genome protection functions. We consider how viral infections modulate telomere regulatory factors for viral repurposing and can alter normal host telomere structure and chromosome stability. Understanding the common strategies of viral and cellular genome maintenance may provide new insights into viral-host interactions and the mechanisms driving genetic instability in cancer.
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Affiliation(s)
- Zhong Deng
- The Wistar Institute Philadelphia, PA, USA
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18
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Schmidt WN, Mathahs MM, Zhu Z. Heme and HO-1 Inhibition of HCV, HBV, and HIV. Front Pharmacol 2012; 3:129. [PMID: 23060790 PMCID: PMC3463857 DOI: 10.3389/fphar.2012.00129] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 06/18/2012] [Indexed: 12/11/2022] Open
Abstract
Hepatitis C virus, human immunodeficiency virus, and hepatitis B virus are chronic viral infections that cause considerable morbidity and mortality throughout the world. In the decades following the identification and sequencing of these viruses, in vitro experiments demonstrated that heme oxygenase-1, its oxidative products, and related compounds of the heme oxygenase system inhibit replication of all 3 viruses. The purpose of this review is to critically evaluate and summarize the seminal studies that described and characterized this remarkable behavior. It will also discuss more recent work that discovered the antiviral mechanisms and target sites of these unique antiviral agents. In spite of the fact that these viruses are diverse pathogens with quite profound differences in structure and life cycle, it is significant that heme and related compounds show striking similarity for viral target sites across all three species. Collectively, these findings strongly indicate that we should move forward and develop heme and related tetrapyrroles into versatile antiviral agents that could be used therapeutically in patients with single or multiple viral infections.
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Affiliation(s)
- Warren N Schmidt
- Department of Internal Medicine and Research Service, Veterans Affairs Medical Center, University of Iowa Iowa City, IA, USA ; Department of Internal Medicine, Roy G. and Lucille A. Carver College of Medicine, University of Iowa Iowa City, IA, USA
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19
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Guo N, Cheng D, Li ZH, Zhou QB, Zhou JJ, Lin Q, Zeng B, Liao Q, Chen RF. Transfection of HCVc improves hTERT expression through STAT3 pathway by epigenetic regulation in Huh7 cells. J Cell Biochem 2012; 113:3419-26. [PMID: 22688977 DOI: 10.1002/jcb.24218] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Ning Guo
- Department of Organ Transplant,Qi Lu hosptial of Shan Dong university,Jinan,250012, China
| | - Di Cheng
- Department of Oncology, Sun Yat‐sen Memorial Hospital of Sun Yat‐sen University, Guangzhou 510120, China
| | - Zhi Hua Li
- Department of Oncology, Sun Yat‐sen Memorial Hospital of Sun Yat‐sen University, Guangzhou 510120, China
| | - Quan Bo Zhou
- Department of Hepatobiliary Surgery, Sun Yat‐sen Memorial Hospital of Sun Yat‐sen University, Guangzhou 510120, China
| | - Jia Jia Zhou
- Department of Hepatobiliary Surgery, Sun Yat‐sen Memorial Hospital of Sun Yat‐sen University, Guangzhou 510120, China
| | - Qing Lin
- Department of Hepatobiliary Surgery, Sun Yat‐sen Memorial Hospital of Sun Yat‐sen University, Guangzhou 510120, China
| | - Bing Zeng
- Department of Hepatobiliary Surgery, Sun Yat‐sen Memorial Hospital of Sun Yat‐sen University, Guangzhou 510120, China
| | - Qiaofang Liao
- Department of Oncology, Sun Yat‐sen Memorial Hospital of Sun Yat‐sen University, Guangzhou 510120, China
| | - Ru Fu Chen
- Department of Hepatobiliary Surgery, Sun Yat‐sen Memorial Hospital of Sun Yat‐sen University, Guangzhou 510120, China
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20
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Kaufer BB, Arndt S, Trapp S, Osterrieder N, Jarosinski KW. Herpesvirus telomerase RNA (vTR) with a mutated template sequence abrogates herpesvirus-induced lymphomagenesis. PLoS Pathog 2011; 7:e1002333. [PMID: 22046133 PMCID: PMC3203187 DOI: 10.1371/journal.ppat.1002333] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 09/08/2011] [Indexed: 02/03/2023] Open
Abstract
Telomerase reverse transcriptase (TERT) and telomerase RNA (TR) represent the enzymatically active components of telomerase. In the complex, TR provides the template for the addition of telomeric repeats to telomeres, a protective structure at the end of linear chromosomes. Human TR with a mutation in the template region has been previously shown to inhibit proliferation of cancer cells in vitro. In this report, we examined the effects of a mutation in the template of a virus encoded TR (vTR) on herpesvirus-induced tumorigenesis in vivo. For this purpose, we used the oncogenic avian herpesvirus Marek's disease virus (MDV) as a natural virus-host model for lymphomagenesis. We generated recombinant MDV in which the vTR template sequence was mutated from AATCCCAATC to ATATATATAT (vAU5) by two-step Red-mediated mutagenesis. Recombinant viruses harboring the template mutation replicated with kinetics comparable to parental and revertant viruses in vitro. However, mutation of the vTR template sequence completely abrogated virus-induced tumor formation in vivo, although the virus was able to undergo low-level lytic replication. To confirm that the absence of tumors was dependent on the presence of mutant vTR in the telomerase complex, a second mutation was introduced in vAU5 that targeted the P6.1 stem loop, a conserved region essential for vTR-TERT interaction. Absence of vTR-AU5 from the telomerase complex restored virus-induced lymphoma formation. To test if the attenuated vAU5 could be used as an effective vaccine against MDV, we performed vaccination-challenge studies and determined that vaccination with vAU5 completely protected chickens from lethal challenge with highly virulent MDV. Taken together, our results demonstrate 1) that mutation of the vTR template sequence can completely abrogate virus-induced tumorigenesis, likely by the inhibition of cancer cell proliferation, and 2) that this strategy could be used to generate novel vaccine candidates against virus-induced lymphoma.
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MESH Headings
- Animals
- Cell Proliferation
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Chickens
- Gene Expression Regulation, Leukemic
- Gene Expression Regulation, Viral
- Herpesvirus 2, Gallid/enzymology
- Herpesvirus 2, Gallid/genetics
- Herpesvirus 2, Gallid/pathogenicity
- Host-Pathogen Interactions
- Lymphoma, T-Cell/genetics
- Lymphoma, T-Cell/veterinary
- Lymphoma, T-Cell/virology
- Marek Disease/genetics
- Marek Disease/virology
- Mutation
- RNA/genetics
- RNA, Viral/analysis
- Telomerase/genetics
- Templates, Genetic
- Vaccination/veterinary
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Affiliation(s)
- Benedikt B. Kaufer
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
- Institut für Virologie, Freie Universität Berlin, Berlin, Germany
| | - Sina Arndt
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Sascha Trapp
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Nikolaus Osterrieder
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
- Institut für Virologie, Freie Universität Berlin, Berlin, Germany
| | - Keith W. Jarosinski
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
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Zemel R, Issachar A, Tur-Kaspa R. The role of oncogenic viruses in the pathogenesis of hepatocellular carcinoma. Clin Liver Dis 2011; 15:261-79, vii-x. [PMID: 21689612 DOI: 10.1016/j.cld.2011.03.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
HBV and HCV have major roles in hepatocarcinogenesis. More than 500 million people are infected with hepatitis viruses and, therefore, HCC is highly prevalent, especially in those countries endemic for HBV and HCV. Viral and host factors contribute to the development of HCC. The main viral factors include the circulating load of HBV DNA or HCV RNA and specific genotypes. Various mechanisms are involved in the host-viral interactions that lead to HCC development, among which are genetic instability, self-sufficiency in growth signals, insensitivity to antigrowth signals, evasion of apoptosis, limitless replicative potential, sustained angiogenesis, and tissue invasiveness. Prevention of HBV by vaccination, as well as antiviral therapy against HBV and for HCV seem able to inhibit the development of HCC.
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Affiliation(s)
- Romy Zemel
- Department of Medicine D and the Liver Institute, Rabin Medical Center, Beilinson Hospital, Molecular Hepatology Research Laboratory, Felsenstein Medical Research Center, Sackler School of Medicine, Tel Aviv University, 39 Jabotinsky Street, Petah-Tikva 49100, Israel
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22
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Ageing, telomeres, senescence, and liver injury. J Hepatol 2010; 53:950-61. [PMID: 20739078 DOI: 10.1016/j.jhep.2010.06.009] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 06/24/2010] [Accepted: 06/26/2010] [Indexed: 02/08/2023]
Abstract
Populations in developed countries continue to grow older and an understanding of the ageing process to allow healthy ageing carries important medical implications. Older individuals are more susceptible to most acquired liver disorders and more vulnerable to the consequences of liver disease. Accordingly, age is a critical determinant of outcome for hepatitis C virus infection and liver transplantation. In this review we describe changes in the ageing liver and discuss mechanisms of senescence at the cellular level. In particular, we focus on mechanisms by which inflammation, oxidative stress, and oncogenic stress accelerate cellular senescence. In the setting of chronic hepatic injury and inflammation, cellular senescence functions as an essential stress-response mechanism to limit the proliferation of damaged cells and reduce the risk of malignancy, but this benefit is achieved at the expense of senescence-related organ dysfunction. The dual role of cell senescence in chronic liver disease will make this an intriguing but challenging area for future clinical interventions.
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