Apoptosis is not induced in CRC cells with mutp53 after 5FU stimuli. a and b, a Fluorescence-activated cell sorting (FACS) assays were used to analyze cell apoptosis after HCT116 WT and SW620 cells were treated with 200 µM 5FU for 24 h. b The percentage of apoptotic cells was calculated from FACS analysis. Data represent the mean±SD of three independent experiments. ***P < 0.001 vs WT. c Hoechst 33,258 morphological examination of apoptosis in HCT116 WT and SW620. Cells were treated with 200 µM 5FU and incubated for 24 h, then stained with Hoechst 33,258. d and e The expression of caspase-3, cleave-caspase 3 (d) and cleave caspase 1 (e) are detected by Western blotting in tree CRC cell lines after 5FU for 24 h.