Figure 6.

RARα is required for effective coactivator loading. MCF-7 cells were hormone-depleted and transfected with control siRNA or siRNA targeting RARα. ChIP of ER (A), p300 (B), or acetylated-H3 (C) was performed after 6 h of vehicle (V) or estrogen (E) treatment, followed by real-time PCR of a number of ER-binding regions. The acetylated-H3 ChIP was first normalized to total H3, then to Input. (D) Following transfection, RNA PolII ChIP was performed, and real-time PCR of the promoter regions of the estrogen-regulated genes was performed. (E) Changes in mRNA levels of the genes were assessed following silencing of RARα. (F) After silencing of control or RARα, total protein levels of ER, p300, and RARα were assessed. (*) P < 0.05; (**) P < 0.01. The data are representative of triplicate experiments, ±SD.