Figure 6.

2-Methoxyestradiol (2ME) induces apoptosis via caspases-8 and 9 in A2780 cells. A, Caspase activity assays (caspase-3, 8, and 9) in A2780 cells after the addition of 2ME 5 μM for 24 hours. Cells in the absence of 2ME are set at 100%. Mann-Whitney test ^★ = P < .05 with respect to control. B, Cell cytotoxicity was measured by the MTS assay, and the data represented as a percentage in respect to control (vehicle, C). Standard deviation of the mean is shown from a minimum of 3 experiments performed, each consisting of 5 replicates. The caspase inhibitors-8, 9, and ZVAD (all 50 μM) were added for 30 minutes previous to and for 24 hours after 2-methoxyestradiol (2ME, 5 μM) addition for 48 hours. Using the Mann-Whitney test, significance was set at P < .05, with ^★ = significant in respect to vehicle. C, Representative flow cytometry analysis of A2780 demonstrating each phase of the cell cycle and an apoptotic sub-GO/G1 peak (a), after treatment with ethanol vehicle (control), 2ME 5 μM for 48 hours, and 2ME (5 μM) for 48 hours in the presence of ZVAD (50 μM). The percentage of apoptotic cells is indicated on top of each figure.