Figure 9.

Alterations of BH4 amounts that altered the ERK and AKT oncogenic signaling pathways. Activation of the ERK and AKT pathways was analyzed in WM1552 radial growth melanoma cells treated with 20 and 40 μM BH4 for 30 min and 4 h (A) and, in WM983B metastatic melanoma cells, treated with 2 and 4 mM DAHP for 30 min and 4 h (B) by Western blot using specific antibodies for phospho- and total ERK and phosphor- and total AKT. GAPDH was used as the internal control. The Western blot images show the representative results of three independent experiments. Values are reported in the bar graphs and expressed as the means ± S.D. The experiments were performed in triplicate, and the p-values were based on the one-way ANOVA test, followed by Bonferroni’s post-test; *, p < 0.05, **, p < 0.01 and ***, p < 0.001.