Fig. 6.

MEK inhibitors reduce viability of a subset of primary human VS cells. (A) Immunohistochemistry shows S100 positivity and variable expression levels of MEK, pMEK, and pERK (green) in VS tumors (4′,6′-diamidino-2-phenylindole nuclear stain, blue). (B) Western blots demonstrate expression of MEK and pMEK for VS with beta-actin as the standard. Relative expression levels of MEK and pMEK were displayed and expressed as a ratio of pMEK/MEK. (C–D) Cell viability assays for PD0325901 and trametinib were performed and viability was normalized to 0.5% DMSO controls.