Fig. 7.

Western blot analysis for detection of interferon (IFN)-γ-mediated caspase-3 activation and consecutive cleavage of poly-adenosine diphosphate-ribose-polymerase (PARP) after inhibition of JAK tyrosine kinase. Caco-2 cells were stimulated for 48 h with IFN-γ (100 ng/ml) and the JAK tyrosine kinase inhibitor alone or in combination. The activation of caspase-3 and consecutive cleavage of PARP were detected using Western blot analysis (48 h in serum-free medium cultured Caco-2 cells were used as controls (a). Caco-2 cells were cultured with IFN-γ and AG490 alone and in combination as indicated. Signal transducer and activator of transcription (STAT)-1 phosphorylation was detected using Western blot analysis (b). After performing Western blotting the caspase-3 activity was also measured semiquantitatively using densitometry and was correlated to β-actin expression. Results after stimulation with IFN-γ were determined as 100% (c).