Figure 1

Sin3A controls basal levels and estrogen-induced responses of genes in breast cancer cells. MCF7 cells were transfected with scrambled (scr.) negative control or Sin3A siRNA, followed by treatment with vehicle control ethanol (EtOH) or 10 nM 17-β-estradiol (estrogen, E2) for four hours. (A) Knockdown of Sin3A protein was confirmed by western blot analysis. The band specific for Sin3A, which is a 145 kDa protein, is marked with an asterisk. The blot was reprobed with β-actin for the loading control. (B) Knockdown of SIN3A mRNA was also verified using quantitative reverse transcriptase real-time PCR (qRT-PCR), with ribosomal protein P0 serving as the housekeeping normalization gene. RNA levels were calculated relative to the scrambled ethanol sample. Data are from four independent experiments with error bars showing the standard error of the mean. Student's t tests were performed comparing corresponding scrambled and Sin3A siRNA samples, *p < 0.05. (C) qRT-PCR data, regulation of basal levels of genes, C3, CLU, ERBB2, and TOP2A. Experiments were performed and data calculated as above. (D) qRT-PCR data, regulation of estrogen responses of genes, NCOA2, MYC, PGR, and TFF1. Experiments were performed as above. RNA levels were calculated for each siRNA group relative to the corresponding ethanol-treated sample. Student's t tests were performed comparing estrogen responses in the presence of scrambled versus Sin3A siRNA for MYC and PGR, and determining significant repression of NCOA2, *p < 0.05.