Fig. 7. uPA-and uPAR-specific antibodies induce apoptosis in MDA-MB-231 cells. (A) MDA-MB-231 cells were cultured in 96-well plates and then incubated in serum-free medium, supplemented with uPA-specific antibody or PD098059 (10 µM) for 24 hours. Cytoplasmic nucleosomes were detected by ELISA. (B) MDA-MB-231 cells were cultured in 6-well plates and treated with DMSO (0.1% v/v), PD098059 (10 µM), mouse nonimmune IgG (25 µg/ml), uPA-specific antibody (25 µg/ml) or uPA-specific antibody (25 µg/ml) plus PD098059 (10 µM) for 24 hours. Caspase-3 activity was then measured. (C) MDA-MB-231 cells were subjected to mild acid wash and then cultured in serum-free medium containing DMSO (0.1% v/v), PD098059 (10 µM), uPAR-specific antibody (50 µg/ml) or uPAR-specific antibody (50 µg/ml) plus PD098059 (10 µM) for 24 hours. Cytoplasmic nucleosomes were detected by ELISA. (D) MDA-MB-231 cells were subjected to a mild acid wash and then cultured for 24 hours in serum-free medium containing DMSO (0.1% v/v), PD098059 (10 µM), rabbit nonimmune IgG (50 µg/ml), uPAR-specific antibody (50 µg/ml) or uPAR-specific antibody (50 µg/ml) plus PD098059 (10 µM). Caspase-3 activity was determined. The asterisk indicates a significant difference compared with control (unpaired t-test, P<0.05, n=3). The dagger indicates that uPA- or uPAR-specific antibody in combination with PD098059 did not significantly alter apoptosis compared with either reagent alone.
