Figure 5.

Dex causes a rapid activation of ERK1/2 in EBV-transformed B cells. (A) Cells were treated with 100 μM Dex for the indicated time periods prior to cell lysis. Total protein was subjected to western blot analysis and successively immunoblotted against MAPKs. (B) Effect of ERK1/2 inhibitor on Dex-induced caspase-9 activation and XAF1 expression. To inhibit ERK1/2 phosphorylation, cells were pretreated with PD98059 (10 μM) for 1 h. (C) Effect of caspase-9 inhibitor on Dex-induced ERK1/2 phosphorylation and XAF1 expression. To inhibit caspase-9 activation, cells were pretreated with z-LEHD-fmk (20 μM) for 2 h. Results are representative of three independent experiments.