Abstract
Recently, the RNA interference (RNAi) pathway has become the target of small molecule inhibitors and activators. RNAi has been well established as a research tool in the sequence-specific silencing of genes in eukaryotic cells and organisms by using exogenous, small, double-stranded RNA molecules of approximately 20 nucleotides. Moreover, a recently discovered post-transcriptional gene regulatory mechanism employs microRNAs (miRNAs), a class of endogenously expressed small RNA molecules, which are processed via the RNAi pathway. The chemical modulation of RNAi has important therapeutic relevance, because a wide range of miRNAs has been linked to a variety of human diseases, especially cancer. Thus, the activation of tumor-suppressive miRNAs and the inhibition of oncogenic miRNAs by small molecules have the potential to provide a fundamentally new approach for the development of cancer therapeutics.