C/EBPα inhibits proliferation of breast cancer cells via a novel pathway of miR-134/CREB.

C/EBPα plays an important role in the modulation of cell proliferation, differentiation or apoptosis in various tissues. Most recently, reduced expression of C/EBPα and growth inhibitory effect was found in primary mammary carcinomas. However, the underlying mechanism is still not fully aware. Here, we firstly identified miR-134 as a target of C/EBPα in MCF7 breast cancer cell lines. C/EBPα overexpression promoted miR-134 expression, causing suppression of apoptosis- protective genes CREB and Bcl-2, and resulted in the proliferation inhibition of MCF7 cells. Moreover, anti-miR-134 rescued the proliferation inhibition of MCF7 cells and the suppression of anti-apoptotic genes CREB and Bcl-2 caused by C/EBPα overexpression. Collectively, C/EBPα inhibited cell growth in breast cancer cells via a novel pathway miR-134/CREB.