2-Methoxyestradiol (2ME) induces apoptosis in a concentration-dependent manner. A, Concentration-response curve in the presence of 2-methoxyestradiol (2ME, μM) for 48 hours in A2780 cells. Cell cytotoxicity was measured by the MTS assay, and the data represented as a percentage in respect to control. Standard deviation of the means is shown from a minimum of 3 experiments performed, each consisting of 5 replicates. Mann-Whitney test ★ = P < .05 with respect to control (vehicle), # = P < .05 in respect to previous concentration. B, Western blot analysis in A2780 cells demonstrating the presence of cleaved PARP after the addition of varying concentrations of 2ME for 48 hours. C, DNA fragmentation analysis of apoptosis induced by 2ME for 48 hours in comparison to vehicle treated controls (C).