Figure 8

Increased caspase 8 and 9 activation in N-ras^-/-and H-ras^-/-/N-ras^-/- fibroblasts. Caspase 8 and 9 activities were measured as described in Materials and methods in WT, N-ras^-/- and H-ras^-/-/N-ras^-/- cell lines that had been subjected to different culture conditions, including, as indicated, serum starvation for 24 hours or subsequent stimulation with serum for 1 hour or 8 hours. Three separate determinations were performed where all individual assays were carried out in triplicate. All values were normalized against their respective N-ras WT controls. Error bars indicate standard deviation (*P < 0.05; **P < 0.01).