Jac-A induced caspase-dependent apoptosis in K562 cells. (A) Cyt c release in Jac-A-induced apoptosis of K562 cells. 106 of K562 cells were treated with different concentration of Jac-A for 48 h. Cytosol and mitochondrial heavy membrane samples were prepared and subjected to immunoblot with anti-Cyt c specific antibodie as described in Materials and methods. The results are one representative of three independent experiments. (B) Western blot showing conspicuous cleavage of caspase-3, caspase-9, and PARP in K562 cells treated with Jac-A. K562 cells subjected to protein extract preparation after treated with 0 (control), 3, 6, 12 μM/L Jac-A for 48 h. Then, fifty micrograms extracted protein subjected to Western blot using anti-PARP, PARP, cleaved caspase-9, caspase-9, cleaved caspase-3, caspase-3, and β-actin. The results are one representative of three independent experiments. (C) Jac-A-induced apoptosis was inhibited in a concentration dependent manner by the Z-VAD-fmk. K562 cells were first treated with or without different concentrations of Z-VAD-fmk for 4 h, followed by the treatment of Jac-A (10 μM) for 48 h.