Khz-cp induces apoptosis through a mitochondrial pathway. (A) SNU-1 cells were treated with a 1:100 dilution of Khz-cp, and caspase or PARP activation was analyzed by immunoblotting. (B) Immunoblot analysis of cytochrome c levels in cytosolic and mitochondrial fractions of SNU-1 cells treated with Khz-cp 1 h. (C) Cells were pretreated with z-VAD-fmk (20 μM) for 1 h and treated with Khz-cp at the same concentrations used in Figure 2(B). After 1 h, the cells were stained with propidium iodide (PI) and annexin-V-FITC (An) for fluorescent microscopy. (D) SNU-1 cells stably transfected with Bcl-2 cDNA or an empty vector (pcDNA3) were treated with Khz-cp for 1 h. Apoptosis was analyzed as in Figure 2(C). (E) Cells were pretreated with CsA (10 μM) for 1 h. Khz-cp treatment and apoptosis analysis were performed as in Figure 2(B). After 1 h, the cells were stained with PI and An for fluorescent microscopy.