Figure 5.

Effects of nuclear and cytoplasmic PARP-1 expression on TRA-8-induced survival signaling in the DISC. BxPc-3 cells were stably infected with Vector, wild-type PARP-1 (WT) or PARP-1 cytoplasmic mutants (R208Q, K222I). (a and b) Cells were exposed to vehicle or TRA-8 (1 μg/mL) for 30 min. The expression and activation of survival signal, Src, and apoptotic signal, caspase-8 (Casp8), was determined by Western blot analysis (a) in cell lysates; or (b) in DR5-associated complex immunoprecipitated with DR5 antibody. Representative blots from three independent experiments are shown. (c) Western blot analysis of Src activation in response to TRA-8 treatment at different time points. Representative results from three independent experiments are shown. (d) Western blot analysis of Src activation in representative xenografted tumors derived from BxPc-3 cells overexpressing Vector, wild-type (WT) or cytoplasmic mutant PARP-1 (K222I). The expression of GAPDH was used as a loading control.