FIG 7.

Components of the SWI/SNF and the TOP2β/PARP-1 complexes are recruited to and required for the transcriptional activation of endogenous pS2 in MCF-7 cells. (A) siRNA-mediated protein knockdown analysis to evaluate the requirement of the SWI/SNF chromatin remodeling complex and members of the TOP2β/PARP-1 complex in ER-mediated transcriptional activation. Reverse transcription–real-time PCR analysis was used to determine the level of transcriptional activation from the endogenous ER-responsive gene pS2 in MCF-7 cells upon siRNA protein knockdown. Total RNA, extracted from estradiol (E2)- or vehicle (EtOH)-treated MCF-7 cells transfected with indicated siRNA duplexes, was used as the template for cDNA synthesis. (B) BRG1 and members of the TOP2β/PARP-1 complex are recruited to the endogenous pS2 promoters in MCF7 cells, as demonstrated by ChIP analysis using antibodies specific for ERα, BRG1, Ku70, Ku86, DNAPK, PARP1, and TOP2β.