Inhibition of CD95 signaling with GST-CD95 does not inhibit antitumor drug-mediated cleavage of caspase-8 and PARP. (A) Jurkat, Jurkat-R cells (1 × 10⁶) or (B) CEM cells were pretreated with medium, zVAD-fmk (100 μmol/L), GST-CD95 (100 μg/mL), or GST (100 μg/mL) for 1 hour, and then stimulated with anti-CD95 (20 ng/mL; 3 hours), etoposide (Etopo; 25 μg/mL; 6 hours) and mitomycin C (Mito; 25 μg/mL; 6 hours) or medium (6 hours). Cellular proteins were immunoblotted with (A and B) anti-caspase-8 or (B) anti-PARP as described in Fig 5A. The immunoblots indicate the cleaved intermediate fragments (◂) of caspase-8a and caspase-8b. The anti-PARP immunoblot shows the uncleaved p116 and the cleaved p89 form of PARP (◂).