Fig. 6.

Effect of MHY2256 on caspase activation in HCT116 cells. (A) Cells were treated with increasing concentration of MHY2256 for 24 h, and in vitro caspase-3, -8, and -9 activity assay was assessed using Z-DEVD-pNA, Z-IETD-pNA, and Ac-LEHD-pNA substrates, respectively. Each point represents the mean ± standard deviation (SD) of three independent experiments (*p<0.05, **p<0.01 and ***p<0.001 vs. vehicle-treated cells). (B) HCT116 cells were incubated with 10 µM MHY2256 for 24 h after pretreatment of 50 µM Z-VAD-FMK for 30 min. The cell viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Data shown are representative of three independent experiments. Values represent mean ± SD (n=3), **p<0.01 vs. vehicle-treated cells and ^##p<0.01 vs. MHY2256-treated cells. (C) Expression level of PARP and procaspase 3 were analyzed using western blotting after treatment with 50 µM Z-VAD-FMK, 10 µM MHY2256, or both for 24 h. Results represent three independent experiments. β-actin was used as a loading control.