Apoptosis of colorectal adenocarcinoma induced by 5-FU and/or IFN-gamma through caspase 3 and caspase 8

The cytotoxic effect of 5-FU has been shown by the induction of apoptosis i n cancel cells, and reported to be enhanced by IFN-gamma. We examined the r ole of caspases on the apoptosis induction of 5-FU and IFN-gamma using a co lorectal adenocarcinoma cell line. The activities of caspase 3 and caspase 8 increased when apoptosis was induced by 5-FU and/or IFN-gamma. Moreover, all apoptotic cells showed high caspase 3 activity in these conditions. Alt hough the inhibitors of caspase 3 and caspase 8 inhibit apoptosis, anti-Pas ligand antibody does not affect the apoptosis induced by 5-FU. Thus, caspa se 3 and caspase 8 play crucial roles in apoptosis induced by 5-FU and/or I FN-gamma, regardless of the Fas-Fas ligand system.