Fig. 4.

Cytotoxic and apoptotic effects of gossypol on human breast cancer cells. Cells were treated with different concentrations of gossypol for 24 h for cell viability (a) and apoptosis assay (b). All assays were performed in triplicate. c MDA-MB-468 cells were transfected with mouse double minute 2 (MDM2) siRNA or overexpression plasmid, and then the tumor cells were incubated with different concentrations of gossypol for 24 h followed by cell apoptosis assay. Cells with MDM2 knockdown or overexpression were less responsive to gossypol-induced apoptotic effect than control cells. GAPDH glyceraldehyde-3-phosphate dehydrogenase, PARP poly(ADP-ribose) polymerase