MicroRNAs are endogenous, small, noncoding 21–23-nucleotide RNAs that regulate gene expression by binding to the 3’untranslated region (3’UTR) of the target gene mRNAs to repress translation or induce mRNA cleavage. Thus they play an important role in regulating various cell functions such as development, cell proliferation, differentiation, and apoptosis. Our interest is to identify the differentially expressed miRNAs during various stages of viral infection and the progression towards HCC development, and use them as either diagnostic markers or therapeutic agents. To initiate the study, we have collected the patient samples from various stages of HBV infection and HBV-HCC patients and isolated the microRNAs. We have studied their integrity using bioanalyzer and erforming microRNA microarray. In parallel, we are also trying to determine some of the miRNAs that are modulated during liver injury and fibrosis using in vitro culture model systems. We
over-expressed miRNA-150, miRNA-194,  miRNA-21 in hepatic cells and determining their role in modulating proliferation and apoptosis.