Published online Jan 28, 2016. doi: 10.3748/wjg.v22.i4.1487
Peer-review started: July 27, 2015
First decision: September 11, 2015
Revised: September 25, 2015
Accepted: October 12, 2015
Article in press: October 13, 2015
Published online: January 28, 2016
Processing time: 184 Days and 1.8 Hours
MicroRNAs (miRNAs) are small noncoding RNAs. More than 2500 mature miRNAs are detected in plants, animals and several types of viruses. Hepatitis C virus (HCV), which is a positive-sense, single-stranded RNA virus, does not encode viral miRNA. However, HCV infection alters the expression of host miRNAs, either in cell culture or in patients with liver disease progression, such as liver fibrosis, cirrhosis, and hepatocellular carcinoma. In turn, host miRNAs regulate HCV life cycle through directly binding to HCV RNAs or indirectly targeting cellular mRNAs. Increasing evidence demonstrates that miRNAs are one of the centered factors in the interaction network between virus and host. The competitive viral and host RNA hypothesis proposes a latent cross-regulation pattern between host mRNAs and HCV RNAs. High loads of HCV RNA sequester and de-repress host miRNAs from their normal host targets and thus disturb host gene expression, indicating a means of adaptation for HCV to establish a persistent infection. Some special miRNAs are closely correlated with liver-specific disease progression and the changed levels of miRNAs are even higher sensitivity and specificity than those of traditional proteins. Therefore, some of them can serve as novel diagnostic/prognostic biomarkers in HCV-infected patients with liver diseases. They are also attractive therapeutic targets for development of new anti-HCV agents.
Core tip: Hepatitis C virus (HCV) infection changes the expression of host miRNAs in vitro and in vivo, while host MicroRNAs (miRNAs) in turn regulate HCV life cycle through directly binding to HCV RNA and/or indirectly targeting cellular mRNAs. The miRNA-centered competitive viral and host RNA network displays a cross-regulation pattern between host mRNAs and HCV genome. Evidence based on the miRNA-mediated host/viral interactions suggests that specific miRNAs can serve as novel diagnostic/prognostic biomarkers in HCV-infected patients with liver diseases and therapeutic targets for development of anti-HCV agents in the future.