Trichostatin A and Tamoxifen inhibit breast cancer cell growth by miR-204 and ERα reducing AKT/mTOR pathway.

MicroRNAs (miRs) are small non-coding RNAs aberrantly expressed in human tumors. Increasing evidence suggests that miRNAs are functionally important in cancers. We demonstrated miR-204 exerts its function by targeting gene involved in tumor growth and chemotherapy drugs reactivity. Here, we show that Trichostatin A (TSA) could increase ERα expression in MCF-7 and MDA-MB-231 cells by reducing miR204. Analysis of tumors growth inhibition shows that TSA promotes ERα expression, which could be reversed by miR-204 mimic transfection. When miR-204 is down regulated, the inhibition of TAM on breast cancer cells is enhanced. Caspase 3 activity is also increased. TSA and TAM combination inhibits Mcl-1 expression by decreasing phosphorylation of AKT induced by ERα increase in vivo and in vitro.