Regulation of miRNAs and the expression of target genes are ERα-dependent. (A, B) MCF-7 cells were pretreated with 1 μM ICI 182, 780 or Raloxifene for 6 h, then treated with 10 nM E2 for 48 h, protein was used for detection of bcl-2, cyclinD1 and survivin expression by Western blot. RNA was used to detect the expression of miRNAs by QPCR. * denotes P < 0.05 compared with vehicle control (ethanol). (C, D) MCF-7 cells were transfected with 100 nM ERα siRNA for 24 h, then cells were treated with 10 nM E2 for 24 h and 48 h. Western blot was used to detect the expression of bcl-2, cyclin D1 and survivin. QPCR was used to examine the level of ERα mRNA. (E, F) MDA-MB-231 cells were treated with 10 nM E2 for 24 and 48 h, miRNAs and target genes were examined. MCF-7 cells were used as ER-positive control.