Fig. 2.

Responsiveness of melanoma cell lines to MEK inhibitor trametinib. a Cells were treated with 10 nM trametinib for 48 h and cell viability determined by resazurin reduction assay. Data show cell viability relative to untreated controls (means + S.D. from n = 3 independently performed experiments). b Three responsive and, c three resistant cell lines were treated with increasing concentrations of trametinib or with 10 nM trametinib and 30 µM Q-VD-OPh. The phosphorylation of MEK and ERK kinases were determined (24 h) using multiplex ELISA. Data show averaged median fluorescence intensity (MFI) for each protein (means ± S.D. from n = 3 independent experiments). Western blots show levels of total MEK and total ERK kinases (24 h). β-Tubulin served as loading control. d Three responsive and, e three resistant melanoma cell lines were treated with increasing concentrations of trametinib or with 10 nM trametinib and 30 µM Q-VD-OPh. After 48-h cell death was assessed by propidium iodide uptake and Annexin V-GFP staining. Bars represent mean values ± S.E.M. from three independently performed experiments. Western blots show processing of caspase-3 and PARP at 48 h. β-Actin served as loading control