Figure 3

MEK162 induces apoptosis in drug-sensitive melanoma cells. (A) A panel of melanoma cultures was treated with MEK162 (1000 nM) or left untreated for 72 hours. Cell lysates were analyzed by western blotting using polyclonal antibody recognizing cleaved PARP. Anti-β-actin western blotting was used as a loading control. (B) Cells were treated as in (A) and collected for annexin V/propidium iodide labeling followed by FACS analysis. Viable cells are found in the lower left quadrant, apoptotic cells are in the lower right (early apoptotic) and upper right (late apoptotic/necrotic) quadrants; the upper left quadrant represents pyknotic nuclei. Numbers in each quadrant represent the percentage of cells in the corresponding subpopulation.