Figure 3.
Role of ceramide in TNFα-induced activation of JNK. (A) KG1 cells were prelabeled with [3H]-palmitic acid for 48 hours, washed, and treated with TNFα (20 ng/mL) at the indicated time. Intracellular levels of ceramide were analyzed as described in “Materials and methods.” Results are expressed as the mean values from 3 independent experiments ± SDs. *P < .05. (B) KG1 cells were preincubated or not for 1 hour with JNK inhibitor SP600125 (20 μM) then treated or not with C6-ceramide (10 μM) for 2 hours. Transcripts of hTERT were quantified using the LightCycler TeloTAGGGhTERT quantification kit as previously described. Results are expressed as mean ± SD from 4 independent experiments. ****P < .001; *P = .03.