Figure 3

Sp site contributes to E2-dependent activation of the BRCA1 promoter in Hela cells expressing exogenous ER-α. (a) Hela cells were cotransfected with pGL3BRCA-1 or pSpmut containing a mutated specificity protein (Sp) site plus the empty vector pCR3.1 or pERα. Transfected cells were cultured in Dulbecco's modified Eagle's medium containing 5% charcoal dextran-stripped fetal bovine serum plus vehicle (DMEM) or DMEM plus 10 nmol/l 17β-estradiol (E2) for 24 hours. (b) Hela cells were cotransfected with an empty plasmid (PCR3.1) plus p3xERE or p3XERE plus a vector containing the cDNA for the estrogen receptor (ER)-α (pERα). Bars represent mean luciferase units corrected for the internal control renilla ± standard error from four independent experiments performed in quadruplicate. Asterisks indicate significant E2 activation (*P < 0.05) of BRCA1 promoter activity as compared with vehicle control (DMEM).