The Role of MicroRNA-124-3p in Breast Cancer Stem Cell Inhibition by Benzyl Isothiocyanate.

Abstract

We have shown previously that benzyl isothiocyanate (BITC) derived from cruciferous vegetables inhibits self-renewal of breast cancer stem-like cells (bCSC). The current study provides insights into the mechanism of bCSC inhibition by BITC. Quantitative real time-polymerase chain reaction and western blot analysis were performed to detect microRNAs(miRNAs) and Forkhead box Q1 (FoxQ1) protein expression, respectively. The bCSC were characterized by aldehyde dehydrogenase 1 activity and flow cytometric analysis of CD49f high/CD133high fraction. BITC treatment resulted in induction of miR-124-3p expression in MDA-MB-231 and MCF-7 cells. miR-124-3p did not affect BITC-mediated inhibition of cell migration or cell proliferation but it significantly regulated bCSC in response to BITC. We also found that miR-124-3p directly targets the 3'untranslated regions (UTR) of FoxQ1 and negatively regulates its expression. The BITC-mediated inhibition of bCSC was partially attenuated by miR-124-3p inhibitor. These findings indicate that miR-124-3p plays an important role in BITC-mediated inhibition of bCSC.