Wildtype (A), ERKOα(B), and ERKOβ (C) RPE cells were co-transfected with MMP-2-promoter-luciferase reporter gene constructs containing an Sp1 site (+Sp1) or a deletion removing the Sp1 site (−Sp1) and β-gal. Cells were exposed to either vehicle (V) or 17β-estradiol (E2, 0.1and 1nM) or ICI (1uM) or ICI+E2 (1nM) for 24 hours and cell lysates collected. Data are the ratio of luciferase activity/β-gal expressed as percentage of vehicle control (v). Shown are means ± SEM of cell lysates collected from triplicate wells for each treatment. *p < 0.05, compared to vehicle +p<0.05 1nm E2 compared to ICI+E2, #p < 0.05 compared to same treatment using different constructs, n = 3 individual collections.