Abstract P4-07-12: miR-206 inhibits cell migration through direct targeting of the actin-binding protein coronin 1C in triple-negative breast cancer

Abstract

Abstract Patients with triple-negative breast cancer (TNBC) have an overall poor prognosis, which is primarily due to a high metastatic capacity of these tumors. Novel therapeutic approaches to target the signaling pathways that promote metastasis are desirable, in order to improve the outcome of TNBC patients. A loss of function of a microRNA, miR-206, is related to increased metastasis potential in breast cancers but the mechanism remains to be elucidated. In this study, we show that miR-206 was decreased in TNBC clinical tumor samples and cell lines whereas one of its predicted targets, actin-binding protein CORO1C, was increased. Expression of miR-206 significantly reduced proliferation by inducing a G1-S cell cycle arrest and migration and also repressed CORO1C mRNA and protein levels. We demonstrate that miR-206 interacts with the 3’-untranslated region (3’-UTR) of CORO1C and regulates this gene post-transcriptionally. Further, silencing of CORO1C reduced tumor cell migration and affected the actin skeleton and cell morphology, similar to miR-206 expression, but did not reduce proliferation. Our findings suggest that miR-206 targets CORO1C in TNBC cells, thereby affecting the actin filaments which results in a repressed tumor cell migration. This pathway is a novel mechanism offering a mechanistic basis whereby the metastatic potential of TNBC tumors could be targeted. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-07-12.