MicroRNAs and Hepatocellular Carcinoma

Genomic studies have demonstrated that many portions of the human genome do not encode conventional protein-coding genes, but encode biologically active noncoding RNA species. One class of such small noncoding RNA is microRNA (miRNA), comprised of a group of well-conserved, small RNA molecules (21-23 nucleotides) that can up- or down-regulate gene expression in normal and abnormal cellular activities by base pairing with 3′ untranslated regions (3′ UTRs) of target messenger RNA (mRNA) [1].