Small-Molecule Regulators of MicroRNAs in Biomedicine.

Preclinical Research MicroRNAs (miRNAs) can regulate gene expression at the post-transcriptional level and have been implicated in the development of various human diseases, including cancer. The regulatory networks of miRNAs play a vital role not only in normal physiology but also in pathology and may represent novel targets for drug discovery. Regulation of miRNAs and the elucidation of miRNA networks will advance miRNA-targeted research but are challenging due to a shortage of appropriate tools. Using different assay systems, diverse small molecules with unique miRNA regulatory activity have been identified. These bioactive small molecules not only showed regulation on different miRNAs but revealed previously unknown miRNA networks. Treatment of cancer both in vitro and in vivo with small-molecule regulators of miRNAs has demonstrated their therapeutic potential. In this review, we discuss assay systems for the identification of small-molecule regulators of miRNAs and reported small molecules, and discuss their applications as probes and candidate drug leads.