Fig. 4.
TPA and S-1P inhibit cyt c and Smac/DIABLO release and cell death in U937 cells induced by C6-ceramide.
(A) Cytosolic extracts from U937 cells treated for 5 hours with 25 μM C6-ceramide alone or after pretreatment with 50 nM TPA or 5 μM S-1P for 15 minutes were subjected to 15% SDS-PAGE and immunoblotted with anti-cyt c, anti-Smac/DIABLO, and anti-COX II, as described in Figure 1. (B) U937 cells were treated as described above. Loss of viability was assessed by the MTT assay. Samples were made in quadruplicate. Mean values with standard deviation are shown.
