Hepatitis C virus (HCV) infection is a global health problem and could lead to severe sequels such as liver cirrhosis and hepatocellular carcinoma. Combination of interferon with ribavirin is the standard treatment protocol but about half patients do not mount a sustained response. Hence, unveiling the host factors that are involved in HCV infection is important to discover new strategies to prevent HCV infection and to develop new targeting treatment regimens. The non-coding microRNA (miRNA) has shown to involve in the regulation of hepatitis C virus (HCV) infection and offers an alternative target for developing anti-HCV agent. Recently, using bioinformatic analyses, several liver-abundant miRNAs with target sequences on HCV genome were selective. The anti-HCV analysis was performed by HCV subgenomic replicon cells and J6/JFH-based HCVcc virus system. One of the selective miRNA suppressed HCV replicon activity and down-regulated HCV accumulation leading to reduced infectivity of HCVcc. In addition, the miRNA could be induced by HCV infection. However, the molecular mechanisms regarding the miRNA modulates HCV infection are still not yet completely understood. In this study, we will identify the target sequence of the miRNA with an aim to unveil the miRNA regulatory mechanisms in HCV infection. At first year, the HCV genome will be subjected to mutational analysis to identify the miRNA binding sites. The association of the miRNA and HCV genome physiologically will be confirmed by Ago2-coimmunoprecipitation (Ago2-IP) analysis. At the second year, the promoter of the miRNA will be cloned and the activator which induced the promoter activity during HCV infection will be defined. At the third year, the cellular target of the miRNA which may modulate HCV infectivity will be analysis by systemic analysis by microarray and bioinformatic approach. Together, this study we hope to get a more complete picture to understand the roles of the novel cellular miRNA in anti-HCV activity and shed new insight to understanding the role of host factors in HCV pathogenesis.
