Supression of MAPK signaling by lasiodin.

<p>(<b>A</b>), CNE1 and CNE2 cells were treated with lasiodin at the indicated doses. After 24 hr treatment, the expressions of the phosphorylated or total protein of ERK1/2, JNK and p38 were detected by Western blotting. NPC cells treated with the vehicle control (DMSO) were used as the reference group. GAPDH was used as the control for sample loading. (<b>B</b>), CNE1 and CNE2 cells were treated with the ERK-selective inhibitor (U0126, 20 µM), JNK inhibitor (SB203580, 600 nM) and p38 inhibitor (SP600125, 2.5 µM) for 4 hr, respectively, and then treated with lasiodin at the indicated doses. After 48 hr treatment, cell viability was determined by the MTT assay. The figures are representative of three experiments. The data are presented as mean ± S.D. of three separate experiments. * <i>P</i><0.05, the significant differences between treatment groups without the inhibitor and control groups without the inhibitor. # <i>P</i><0.05, the significant differences between treatment groups with the inhibitor and control groups with the inhibitor.