12B1-D1 cells exposed to AP20187 undergo apoptosis.

(A) The 12B1-D1 clone was cultured in the presence of 40 nM AP20187, and induction of apoptosis was assessed by Annexin V and PI staining at the indicated times. (B) Electron micrographs of 12B1-D1 cells exposed to AP20187 at 0, 6 hours (6000×). (C) DNA fragmentation analysis. Lane 1, 100-bp ladder; lane 2, DNA extracted from 12B1-D1; lane 3, 12B1-D1 + HS (A), cells were heat shocked at 42°C for 1 hour; lane 4, 12B1-D1 + HS (B), cells were heat shocked at 42°C for 1 hour and then incubated for 6 hours at 37°C; lane 5, 12B1-D1 + AP20187 for 6 hours; lane 6, 12B1-D1 + HS for 1 hour + AP20187 for 6 hours.