Studies on circulating microRNAs: Members of Let-7 family and their correlation with Hepatitis C virus disease pathogenesis and treatment concerns

Hepatitis C is a hepatocellular infectious disease caused by a small single stranded positive sense RNA virus, Hepatitis C virus (HCV), ranging from 55–65 nm in size. The 9.6 KB genome of HCV encodes a polypeptide that cleaves into 10 proteins by endonucleases. MicroRNAs (mi-RNA) control the expression of the cell by regulating the gene expression. Mi-RNAs are small in size and consist of 18–25 nucleotides and noncoding single stranded RNA molecules. Mi-RNAs have important role in the regulation of HCV life cycle by interacting directly with HCV genome or controlling host pathways that regulate virus life cycle that is ultimate cause hepatocellular carcinoma. The objective of research study is to monitor the expression levels of mi-RNAs (up-regulation or down-regulations) in HCV propagation in Pakistani population with genotype 3a. For this purpose, expression levels of mi-RNAs of all samples (∼33 samples for members of let-7 family) were examined by Real time PCR (qRT-PCR) using syber green dye. Alteration in the expression profiles of microRNAs in HCV infected individuals have been observed in this research study. Over expression patterns of Members of let-7 family (Let-7c, Let-7g and Let-7i) have been detected in HCV patients as compared to healthy controls. Up-regulated expression of these microRNAs indicates their positive role in the progression of HCV. According to most recent researches, several mi-RNAs play a central role in the regulation of HCV by changing the expression of host gene/s. To test these possibilities, this study was initiated to check and correlate three up-regulated mi-RNAs in Pakistani HCV infected patients.