MicroRNA Expression Profiling in HCV-Infected Human Hepatoma Cells Identifies Potential Anti-Viral Targets Induced by Interferon-α

Objective: Increasing evidence suggests that miRNAs have a profound impact on host defense to Hepatitis C virus (HCV) infection and clinical outcome of standard HCV therapy. In this study, we investigated modulation of miRNA expression in Huh7.5 hepatoma cells by HCV infection and in vitro interferon-alpha treatment. Methods: MiRNA expression profiling was determined using Human miRNA TaqMan (R) Arrays followed by rigorous pairwise statistical analysis. MiRNA inhibitors assessed the functional effects of miRNAs on HCV replication. Computational analysis predicted anti-correlated mRNA targets and their involvement in host cellular pathways. Quantitative RTPCR confirmed the expression of predicted miRNA-mRNA correlated pairs in HCV-infected Huh7.5 cells with and without interferon-alpha. Results: Seven miRNAs (miR-30b, miR-30c, miR-130a, miR-192, miR-301, miR-324-5p, and miR-565) were down-regulated in HCV-infected Huh7.5 cells (p<0.05) and subsequently up-regulated following interferon-alpha treatment (p<0.01). The miR-30(a-d) cluster and miR-130a/301 and their putative mRNA targets were predicted to be associated with cellular pathways that involve Hepatitis C virus entry, propagation and host response to viral infection. Conclusions: HCV differentially modulates miRNAs to facilitate entry and early establishment of infection in vitro. Interferon-alpha appears to neutralize the effect of HCV replication on miRNA regulation thus providing a potential mechanism of action in eradicating HCV from hepatocytes.