Figure 8.

ERα recruits transcriptional corepressors to repress p53-mediated transcriptional activation. (A) ChIP and sequential ChIP assays were performed on MCF-7 cells saturated with 3DPQ-1 to 3DPQ-12 in concentrations of 0.1 and 1 nM (for 3DPQ-5, 3DPQ-6, and 3DPQ-8 the concentrations were 1 and 10 nM) with primers specific to the p53-binding site of the p21 promoter. The primary ChIP was performed with anti-p53 antibody, and the immunoprecipitate was subjected to a second ChIP with anti-ERα antibody; (B) The immunoprecipitate from the ERα ChIP was then subjected to the third ChIP with antibodies against NCoR, SMRT, and HDAC1 antibodies; (C) qChIP was performed to analyze the ERα–p53 interaction on the p21 promoter in MCF-7 cells saturated with 3DPQ-1 to 3DPQ-12. Cells were grown in media with dextran-coated charcoal-treated FBS for 4 d and treated with E₂ (1 and 10 nM) with or without 3DPQ-1 to 3DPQ-12 for 3 h. * p < 0.05 when compared with control group; ^† p < 0.05 when compared with E₂; ^‡ p < 0.05 when compared with 4-OTH; ^§ p < 0.05 when compared with Ral.