Figure 2

Sp site contributes to estrogen-dependent activation of the BRCA1 promoter in breast cancer MCF-7 cells. (a) Cells were precultured for 3 days in phenol red-free Dulbecco's modified Eagle's medium containing 5% charcoal dextran-stripped fetal bovine serum (DMEM). Then, MCF-7 cells were transiently transfected with pGL3BRCA-1, pSpmut, or pCREmut. Cells were cultured in control vehicle (DMEM) or DMEM plus 10 nmol/l 17β-estradiol (E2) for 24 hours. (b) The treatment with E2 induced promoter activity from a positive control vector (p3xERE) transfected into MCF-7 cells. Bars represent mean luciferase units corrected for the internal control renilla ± standard error from three independent experiments performed in quadruplicate. Asterisks indicate significant E2 activation (*P < 0.05) of promoter activity as compared with vehicle control (DMEM) in cells transfected with pGL3BRCA-1, pSpmut, or pCREmut.