Fig. 4.

Quantitation of pERK and pMEK levels in tumor cell lines with mutant and WT BRAF. pERK and pMEK were quantitated by immunoblotting cell lysates from 13 tumor cell lines with ^WTBRAF or ^V600EBRAF. Cells grown in 10% FBS were harvested at 70–80% confluence, and lysates resolved by SDS/PAGE were probed for pERK (phosphorylated p44/ p42 MAPK), pMEK, total ERK, and total MEK 1/2. Band intensity was quantitatively measured by densitometry reading of the immunoblot [P value (one-sided Wilcoxon) is cited in text for difference in pMEK expression between groups].