Figure 3.

The involvement of caspase-3 in AF-induced apoptosis. (a) Western blot analysis of PARP in NB4 cells treated with AF. After treatment with 1 μM AF, the cells were lysed and 40 μg of protein was electrophoresed on a 4–20% gradient SDS–polyacrylamide gel. Note that an 85 KDa fragment, which was the product of PARP cleavage by caspase-3, could be detected in AF-treated cells. (b) Inhibition of AF-induced apoptosis by a caspase-3 inhibitor. The BrdU-labelled NB4 cells were preincubated for 1.5 h with z-DEVD (200 μM) or DMSO (0.4%), which was used as a solvent for the inhibitor, before exposure to AF (1 μM). The DNA fragment was detected by the same method as in Figure 2(c).