(A) Cells grown in complete media (10% FBS) were lysed and analyzed by Western Blot (WB) for IGF-1R, p53 and phosphorylated ERK1/2 (pERK1/2) alongside GAPDH or total ERK1/2 (ERK1/2) as loading controls. (B, C, D) Effect of MEK1/2 inhibitor U0126 on melanoma cell viability. DFB, BE and Mel28 cells were treated as indicated, in serum (B, C) or SFM (D), total cell number was evaluated by PrestoBlue fluorescence, and expressed as a % of DMSO (solvent only) treated control. Data displayed as mean ± S.E.M from three independent experiments. (B) Dose response, with increasing doses of U0126 for 72 h (C) Time response, 20 μM U0126 for times indicated. (D) Cells in serum free media (SFM) or 50 ng/mL IGF-1 were treated as indicated. Statistical analysis: (B) U0126 treated cells compared with control-treated cells. (D) Cells treated with U0126 in the presence of IGF-1 compared to SFM conditions. *P<0.05, **P<0.01, ***P<0.001.