Caspase 3 induction was inhibited by a caspase 3 inhibitor, but not the caspase 1 inhibitor.

No induction or inhibition was detected for caspase 1. (A) Immunoblots (caspase 1 and caspase 3) of lysates from JY and HSC536N cells pretreated for 30 minutes with either 50 μmol/L of ac-YVAD-cho (indicated by Y) or 50 μmol/L ac-DEVD-cho (indicated by D), and then exposed to 100 ng/mL agonistic anti-fas antibody and 1.0 ng/mL IFN-γ for 60 minutes. Proteins were separated on a 15% SDS-PAGE to immunoblot for caspase 1 p10 and a 12% SDS-PAGE to immunoblot for caspase 3 p20. (B) Fluorogenic assays for caspase 3 using EBV- transformed normal and FA-C isogenic cell lines (JY, HSC536N, HSC536N FANCC/neo, and HSC536N neo). Cells were exposed to 100 ng/mL anti-fas antibody and 1.0 ng/mL IFN-γ for 120 minutes. High-level caspase 3 activation consistently resulted from this treatment. Addition of ac-DEVD-cho prevented caspase 3 activation but ac-YVAD-cho did not. Graphic data are representative of at least 3 experiments.