induced bcl-2, cyclin D1 and survivin expression in MCF-7 cells. (A) MCF-7 cells were incubated with phenol red-free IMEM supplemented with 5% charcoal stripped FBS for 48 h (serum-starved). Then cells were treated with vehicle control or 10 nM E2 for 6, 24 and 48 h, total protein was extracted to detect the expression of bcl-2, cyclin D1 and survivin by Western blot. (B) The densitometry of each gene vs. β-actin was indicated and the statistical analysis was shown. * denotes P < 0.05 compared with vehicle control.