MicroRNAs are a class of endogenous regulators of gene function. Aberrant regulation of microRNAs has been linked to various human diseases, most importantly cancer. Small molecule intervention of microRNA misregulation has the potential to provide new therapeutic approaches to such diseases. microRNA miR-122 is the most abundant microRNA in the liver and is involved in hepatocellular carcinoma development and hepatitis C virus (HCV) infection. Small molecule inhibitors and activators of the microRNA miR-122 are described, and methods for their identification are reported. These small molecule inhibitors reduce viral replication in liver cells and thus represent a new approach to the treatment of HCV infections. Moreover, small molecule activation of miR-122 in liver cancer cells selectively induced apoptosis through caspase activation, and thus has implications in cancer chemotherapy.
