Fig. 5

Activation of MAPK pathway by dTCTP in BEAS-2B cells. a AP-1-driven luciferase activity was measured in dTCTP-treated BEAS-2B cells that were transiently transfected with pAP-1-Luc. To compensate for transfection efficiency, cells were co-transfected with pRL-TK vector, and the results are presented as a ratio of firefly luciferase to Renilla luciferase. Values represent mean ± SEM (n = 3). *p < 0.05, significantly different from untreated group. b BEAS-2B cells were treated with 10 μg/ml of dTCTP for the times indicated. The whole cell lysates were analyzed by immunoblotting. Results are representative of at least three experiments. c When BEAS-2B cells were treated with PD98059 (a MEK1 inhibitor), SP600125 (a JNK inhibitor) or SB203580 (a p38 MAPK inhibitor) for 30 min prior to exposure to dTCTP (10 μg/ml), IL-8 production was blocked in a dose-dependent manner. Values represent mean ± SEM, n = 3. ^‡p < 0.01; control vs PD98059, ^††p < 0.01; control vs SP600125 and *p < 0.05, ***p < 0.001; control vs SB203580