Figure 5.

Effects of FB₁ and caspase inhibition on 4HPR action. MCF-7 cells were grown over a 3-day period in the absence (open bars) or presence (hatched bars) of 4HPR (5 μM), and in the absence or presence of FB₁ (25 μM) or Z-VAD fmK (50 μM). (A) ceramide production was measured after 24 h by incorporation of [³H]palmitic acid (see Materials and Methods). (B) cell survival was measured after 72 h by the MTS assay (see Materials and Methods). ^*P<0.01 for significant changes vs control values measured in the absence of 4HPR; ^**P<0.02 for significant changes vs control values measured in the presence of 4HPR.