miR-145 suppresses breast cancer cell migration by targeting FSCN-1 and inhibiting epithelial-mesenchymal transition.

MicroRNAs (miRNAs), small non-coding RNAs, regulate fundamental cellular and developmental processes such as cell growth, apoptosis, migration, and invasion. In our present study, we investigated the inhibitory role of miR-145 on breast cancer cell migration as well as its underlying mechanism. Wound healing assay and transwell migration assay showed that ectopic expression of miR-145 significantly inhibited breast cancer cell migration. Bioinformatics analysis revealed that FSCN-1 was a putative target of miR-145. The expression of FSCN-1 varied among four different breast cancer cells, and inversely correlated with miR-145 levels. Moreover, miR-145 mimic transfection enhanced the expression of FSCN-1 in Bcap-37 and HCC-1937 cells. We also found that siRNA- mediated down-regulation of FSCN-1 inhibited cell motility in breast cancer cells. In addition, we found that up-regulation of miR-145 blocked EMT and decreased the expression of MMP-2/9 in breast cancer cells. These results reveal a new link between miR-145, FSCN-1 and EMT in the regulation of breast cancer migration.