MicroRNA and cancer chemoprevention.

MicroRNAs (miRNA) are a group of naturally occurring, small, noncoding, and single-strand RNA molecules that regulate gene expression at the posttranscriptional and translational levels. By controlling the expression of oncogenic and tumor suppressor proteins, miRNAs are believed to play an important role in pathologic processes associated with malignant progression including tumor cell proliferation, apoptosis, differentiation, angiogenesis, invasion, and metastasis. However, relatively few studies have investigated the influence of chemopreventive agents on miRNA expression and their regulation of target genes. Given the significance of miRNAs in modulating gene expression, such research can provide insight into the pleiotropic biologic effects that chemopreventive agents often display and a deeper understanding of their mechanism of action to inhibit carcinogenesis. In addition, miRNAs can provide useful biomarkers for assessing antineoplastic activity of these agents in preclinical and clinical observations. In this review, we summarize recent publications that highlight a potentially important role of miRNAs in cancer chemoprevention research.