Figure 2. Effects of E₂, the ERα-selective agonist PPT, the ERβ-selective agonist DPN, and the GPER-selective agonist G1 on the growth of HGSOC cell lines (PEO1, HEY, COV318 and NIH:OVCAR-3).

Cells were treated with various concentrations of substances in phenol-red free medium supplemented with charcoal stripped FBS. Concentrations are expressed in nanomolar. Control cells received the same amount of diluent. The medium was renewed after 48 hours. At 120 hours of incubation viable cells were counted using Nucleocounter. All results are expressed as the mean ± SEM derived from at least three different experiments. A. In PEO1 cells growth was modulated by E₂ or selective agonist treatment, an effect reverted by the ER antagonist ICI 182,780 (10 and 100 nM) (*P<0.05, **P<0.01, ***P<0.001). To confirm the E₂-induced modulation of cell proliferation, cyclin D1 and cyclin E was evaluated by western blot analysis after 120 hours treatment. Quantitated protein levels were normalized to β-actin (*P<0.05, **P<0.01). B. The proliferation of NIH:OVCAR-3, COV318 and HEY was not modulated by either the endogenous or the selective synthetic ligands. MCF-7 cells were used as positive control.