Abstract
MicroRNAs (miRNAs) have been demonstrated to serve an important role in diverse biological processes and cancer progression. Downregulation of microRNA-497 (miR-497) has been observed in human colorectal cancer (CRC) tissues, but the function of miR-497 in CRC has not been well investigated. In the present study, it was demonstrated that expression of miR-497 was significantly downregulated in human CRC tissues compared to adjacent normal tissues. Enforced expression of miR-497 inhibited proliferation, migration and invasion abilities of CRC cell lines SW1116 and SW480. Furthermore, overexpression of miR-497 inhibited phosphoinositide 3-kinase/AKT and mitogen-activated protein kinase/extracellular signal-regulated kinase signaling by targeting insulin receptor substrate 1 (IRS1). In human clinical specimens, IRS1 was inversely correlated with miR-497 in CRC tissues. Collectively, the results of the present study demonstrate that miR-497 is a tumor suppressor miRNA and indicate its potential application for the treatment of human CRC in the future.