Activation of <i>vav</i>1 promoter by ERα.

<p>MCF7 cells were transfected with the <i>vav</i>1 luciferase reporter gene, and cultured in RPMI 1640 medium for 24 h. The cells were pre-treated with increasing concentration of Tamoxifen (A) or ICI 182 782 at 4×10⁻⁷ mol/L (B) for 30 min, followed by E₂ treatment for another 48 h. Or the cells were treated with E₂ (10⁻⁷ mol/L), PPT (10⁻⁷ mol/L), or DPN (10⁻⁷ mol/L) for 48 h (C). The DMSO treatment served as solvent control. The induction fold of luciferase activity was measured as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099052#s2" target="_blank">Methods</a>, and plotted as the ratio to that of the control in <i>y</i>-axis. The data represented the mean±S.D. of three independent experiments. “**” and “N.S.” indicate P<0.01 and P>0.05, respectively, versus DMSO treatment by unpaired student T test; “a**” and “aN.S.” indicate P<0.01 and P>0.05, respectively, versus E₂ treatment.