Fig. 4.

Three types of selective inhibitors of MAPK signaling produce expected differential kinase inhibition and activation responses in HCT116 colorectal cancer cells. HCT116 cells were treated with 250 nm of GDC-0973, GDC-0623, SCH772984 or DMSO for 1, 4, or 24 h. In the washout samples, cells were drug treated for 24 h, then changed into fresh media and harvested after 0.5 or 2 h. Lysates were used for Western blots of total and phosphorylated MEK, ERK, and RSK; blotting for COX IV was used as the loading control.