Inhibition of subgenomic hepatitis C virus RNA in Huh‐7 cells: ribavirin induces mutagenesis in HCV RNA

Kanda, Tatsuo; Yokosuka, Osamu; Imazeki, Fumio; Tanaka, Mariko; Shino, Yuji; Shimada, Hiroyasu; Tomonaga, T.; Nomura, Fumio; Nagao, Keiichi; Ochiai, Toshimasa; Saisho, Hiromitsu

doi:10.1111/j.1365-2893.2004.00531.x

Cited by 56 publications

(49 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, combined with IFN, ribavirin enhanced the IFN effect by 1.46-to 1.62-fold; this boost may be crucial to clear the virus and may improve the efficacy of IFN therapy. Several previous reports have described increases in mutation frequencies induced by ribavirin (4,13,18,28). However, this mutagen effect of ribavirin was not detected in this study.…”

Section: Discussioncontrasting

confidence: 54%

“…Using this replicon system, the anti-HCV effects of IFN and ribavirin have been evaluated (13,18,28,33). However, a number of these previous studies could not observe the anti-HCV effect of ribavirin in lower concentrations.…”

Section: Discussionmentioning

confidence: 99%

“…The mutagen effect of ribavirin has been previously described (4,5,13,28). To assess the mutagen effect of ribavirin in this system, sequences of replicating reporter replicon RNAs in Huh7 cells were determined after treatment with IFN (10 IU/ml), ribavirin (3 g/ml), or both.…”

Section: Vol 43 2005 Anti-hcv Effect Of Ifn and Ribavirin 5681mentioning

confidence: 99%

See 2 more Smart Citations

Detection of Anti-Hepatitis C Virus Effects of Interferon and Ribavirin by a Sensitive Replicon System

et al. 2005

View full text Add to dashboard Cite

Although combination therapy with interferon and ribavirin has improved the treatment for chronic hepatitis C virus (HCV) infection, the detailed anti-HCV effect of ribavirin in clinical concentrations remains uncertain. To detect the anti-HCV effect of ribavirin in lower concentrations, a sensitive and accurate assay system was developed using the reporter replicon system with an HCV genotype 2a subgenomic replicon (clone JFH-1) that exhibits robust replication in various cell lines. This reporter replicon was generated by introducing the luciferase reporter gene (instead of the neomycin resistance gene) into the subgenomic JFH-1 replicon. To assess the replication of this reporter replicon, luciferase activity was measured serially up to day 3 after transient transfection of Huh7 cells. The luciferase activity increased exponentially over the time course of the experiment. After adjustment for transfection efficiency and transfected cell viability, the impacts of interferon and ribavirin were determined. The administration of interferon and ribavirin resulted in dosedependent suppression of replicon RNA replications. The 50% inhibitory concentration of interferon and ribavirin was 1.80 IU/ml and 3.70 g/ml, respectively. In clinical concentrations, replications were reduced to 0.09% and 53.74% by interferon (100 IU/ml) and ribavirin (3 g/ml), respectively. Combination use of ribavirin and interferon enhanced the anti-HCV effect of interferon by 1.46-to 1.62-fold. In conclusion, we developed an accurate and sensitive replicon system, and the antivirus effect of interferon and ribavirin was easily detected within their clinical concentrations by this replicon system. This system will provide a powerful tool for screening new antiviral compounds against HCV.Hepatitis C virus (HCV) is a major public health problem, infecting an estimated 170 million people worldwide. HCV causes chronic liver diseases, including cirrhosis and hepatocellular carcinoma, because most patients fail to clear the virus and the persistent infection that follows (1,11,20). Current therapy for HCV-related chronic hepatitis is based on the use of interferon (IFN). However, virus clearance rates are limited to approximately 10 to 20% of cases treated with IFN only (9,23,26). Combination therapy with IFN and ribavirin improves the HCV clearance rate, although the molecular mechanism responsible for this improvement is not yet fully understood (23,25,26). However, some direct antiviral mechanisms of ribavirin have been proposed (19). One possible mechanism is the direct inhibition of HCV RNA-dependent RNA polymerase, and another possibility is the RNA mutagen effect that drives a rapidly mutating RNA virus over the threshold to "error catastrophe." The detection of these direct anti-HCV effects has been hampered by the lack of an appropriate sensitive system for evaluating HCV replication.Although HCV belongs to the Flaviviridae family and has a genome structure similar to those of the other flaviviruses (3, 27), efficient cell culture systems a...

show abstract

Section: Discussioncontrasting

confidence: 54%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Detection of Anti-Hepatitis C Virus Effects of Interferon and Ribavirin by a Sensitive Replicon System

et al. 2005

View full text Add to dashboard Cite

show abstract

“…In studies using HCV replication models, mutagenic effects of ribavirin have been identified by several 54,[56][57][58][59][60] but not all authors. 61 When infectivity was used as a functional readout for mutagenesis, diminished infectivity was found with ribavirin treatment of HCV cultures.58 , 60 The concentrations of ribavirin needed to achieve mutagenic effects were high (up to 400 uM) and may exceed those achieved in vivo.…”

Section: Ribavirin: Mechanism Of Action Clinical Insightsmentioning

confidence: 99%

Mechanisms of action of interferon and ribavirin in chronic hepatitis C: Summary of a workshop

et al. 2007

View full text Add to dashboard Cite

The current recommended therapy for chronic hepatitis C is the combination of peginterferon and ribavirin, which results in a sustained clearance of hepatitis C virus (HCV) in at least half of patients. However, the mechanisms by which interferon alpha (IFN-α) and ribavirin act against HCV are not well defined. The importance of understanding the biological pathways, cellular effects, and antiviral activities of these agents is underscored by clinical observations that nonresponders frequently have little or no decrease in HCV RNA levels during treatment, suggesting intrinsic resistance to IFN-α. Cell culture and animal models of HCV have shown that the infection itself may block IFN-α induction and action. Still other findings suggest that individual innate and adaptive immune responses, host genetic factors, viral genetic diversity, and clinical comorbidities account for part of nonresponse to therapy. To provide an overview of the current knowledge of the mechanisms of action of IFN-α and ribavirin against HCV and offer guidance for future research, the American Association for the Study of Liver Diseases held a single topic conference entitled "Interferon and Ribavirin in Hepatitis C Virus Infection: Mechanisms of Response and Non-Response" on March [1][2][3] 2007. This article summarizes that conference. Interferons (IFNs): An OverviewThe IFNs (Dr. Howard Young, National Cancer Institute, National Institutes of Health)The type 1 IFNs [interferon alpha and beta (IFN-α/β)] comprise a family of distinct proteins1 that are produced by a wide variety of cells, including fibroblasts, epithelial cells, and hepatocytes, 2 although plasmacytoid dendritic cells (DCs) are probably the major source in most viral infections. In contrast, type II IFN [interferon gamma (IFN-γ)] is a single gene cytokine unrelated in structure to IFN-α/β that is produced largely by macrophages, natural Copyright © 2007 by the American Association for the Study of Liver Diseases.Address reprint requests to: Raymond T. Chung, M.D., Gastrointestinal Unit, GRJ724, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114. rtchung@partners.org; fax: 617-643-0446.. Potential conflict of interest: Dr. Lemon is a consultant for Novartis, GlaxoSmithKline, Hoffman-LaRoche, Genelabs Technology, Abbott, Pharmasett. He also received grants from Schering-Plough and Tibotec. Dr. Chung received grants from Roche and ScheringPlough. NIH Public Access Author ManuscriptHepatology. Author manuscript; available in PMC 2009 December 29. Published in final edited form as:Hepatology. 2008 January ; 47(1): 306-320. doi:10.1002/hep.22070. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript killer (NK) cells, and T lymphocytes. Both types of IFNs interact with cells via distinct cellular receptors. The details of the signaling mechanisms by which IFN-α/β and IFN-γ induce the transcription of interferon-stimulated genes (ISGs) and depress the transcription of others are still being defined. 3 However, it is increasingly clear that the c...

show abstract

“…The region of the viral genome that codes for NS5B has been described as an important target in therapy with IFN and rBV (Kukolj et al 2005, Lu et al 2007, Lutchman et al 2007). The mechanisms that lead to viral resistance after IFN/ rBV treatment is still a matter of debate (Horiike et al 1999, Hadziyannis et al 2004, Kanda et al 2004, Hamano et al 2005, Hofmann et al 2007, Chung et al 2008, Kuntzen et al 2008, Kwong et al 2008, Nakamura et al 2008, Cannon et al 2009, Gaudieri et al 2009, rydberg et al 2009). For instance, Nelson et al (1995) showed that the mutations that occur in the HCV gene that codes for NS5B did not correlate with response to INF therapy, but Japanese studies associated IFN-rBV failure with mutations in the NS5B gene (Hamano et al 2005, Hmwe et al 2010 and Kuntzen et al (2008) showed that mutations conferred resistance to specifically targeted antiviral therapy drugs in treatmentnaïve patients infected with HCV genotype 1.…”

mentioning

confidence: 99%

Association of hepatitis C virus NS5B variants with resistance to new antiviral drugs among untreated patients

Castilho

Martins

Horbach

et al. 2011

Mem. Inst. Oswaldo Cruz

View full text Add to dashboard Cite

Inhibition of subgenomic hepatitis C virus RNA in Huh‐7 cells: ribavirin induces mutagenesis in HCV RNA

Cited by 56 publications

References 48 publications

Detection of Anti-Hepatitis C Virus Effects of Interferon and Ribavirin by a Sensitive Replicon System

Detection of Anti-Hepatitis C Virus Effects of Interferon and Ribavirin by a Sensitive Replicon System

Mechanisms of action of interferon and ribavirin in chronic hepatitis C: Summary of a workshop

Association of hepatitis C virus NS5B variants with resistance to new antiviral drugs among untreated patients

Contact Info

Product

Resources

About