(A) Recruitment of ERα at the pS2 proximal promoter. MCF-7:5C and MCF-PF cells were treated with vehicle (0.1% EtOH; con), E2 (10−9 mol/L), and 4-OHT (10−6 mol/L) for 45 min. ChIP assay was performed as in Materials and Methods. p<0.05, * compared with control, p<0.001, ** compared with control. (B) Recruitment of SRC3 at the pS2 proximal promoter. MCF-7:5C and MCF-PF cells were treated the same as above. ChIP assay was performed as described in Materials and Methods. p<0.05, * compared with control, p<0.001, ** compared with control. All the data shown are representative of at least three separate experiments with similar results.