Impact of 17β-estradiol and estriol on proliferation of TNBC cells. Cells of a GPR30 positive (HCC1806) and a GPR30 negative TNBC cell line (MDA-MB-231) were grown for 7 days in culture medium supplemented with charcoal-treated FCS either in the presence of 10-12 M to 10-6 M 17β-estradiol (A and
B) or 10-6 M to 8×10-5 M estriol (C and
D). Cell number was evaluated in microwell plates by a colorimetric assay using Alamar blue. Optical densities (OD) measured in the non-stimulated wells (control) were set 100%. The ODs estimated in the stimulated wells were divided by the average value of the control wells to give the relative cell number in % of control achieved under the indicated conditions. (a) p < 0.05 vs. control; (b) p < 0.01 vs. control. Data are mean values and SE of three independent experiments with four replicates.