FIGURE 10.

Selective cell death of HEK-ABCG2 cells occurs through caspase-3/7-dependent apoptosis. Cells were incubated in the absence or presence of 35 nm gA, a combination of 35 nm gA and 2 μm curcumin (Cur), 7.5 nm ouabain (Oua), and a combination of 7.5 nm ouabain and 2 μm curcumin for 72 h. A, cells were stained with CellEvent caspase-3/7 green detection reagent and analyzed subsequently by flow cytometry. Bars represent the percentages of caspase-3/7 activated cells of the total population. B, cells were stained with both CellEvent caspase-3/7 green detection reagent and SYTOX AADvanced dead cell stain and analyzed subsequently by flow cytometry. The dark gray bars indicate the population of early apoptotic cells (CellEvent caspase-3/7 green +/SYTOX AADvanced −), whereas the light gray bars indicate the population of late apoptotic or necrotic cells (CellEvent caspase-3/7 green +/SYTOX AADvanced +). C, cells were incubated with 50 μm Z-VAD-FMK for 2 h prior to the addition of various compound(s) for 72 h and subsequently stained with annexin V-FITC/EthD I for flow cytometry analysis. The dark gray bars indicate the population of early apoptotic cells (annexin V-FITC +/EthD I −), whereas the light gray bars indicate the population of late apoptotic or necrotic cells (annexin V-FITC +/EthD I +). p values indicate no significant difference between HEK-control and ABCG2 cells in the presence of Z-VAD-FMK.