Expressions of p-p90RSK and p-MSK1 induced by U0126 (20 µM), melatonin (10 µM) alone and both U0126 and melatonin in hFOB 1.19 cells for 24 h. (a) Total and phosphorylated (p-) expression levels were measured by Western blot; (b) ratio of p-p90RSK/p90RSK; (c) ratio of p-MSK1/MSK1. Expression levels were normalized by GAPDH first. Each bar is indicated as the relative percentage of control cells. The results are represented as the means ± SEM of three independent experiments. **
p < 0.01, compared with control cells; ##
p < 0.01, compared with the melatonin treatment group; &&
p < 0.01, &
p < 0.05, compared with the U0126 treatment group.