Figure 6.

Phospho-ERK1/2 rebound is not essential for apoptosis bypass in resistant cells. (a) Parental and resistant cells treated with DMSO or 5 μM PLX4720 or a combination of 5 μM PLX4720 and 5 μM AZD6244 for 48 h. Cells were then harvested and stained with annexin V. Quantitation of annexin V staining-positive cells from three experiments is shown. X axis, treatment conditions; Y axis, mean percentage of annexin V-positive cells. Error bars represent standard deviation. Left: WM793 and WM793-Res cells; Right: M238 and M238-Res cells. (b) Same as (a) except that after 24 h of inhibitor treatment, cells were lysed for western blot analysis on Bim-EL protein using actin as loading control. (c) Same as (b) except total RNA was isolated from cells for qRT-PCR analysis on Bim-EL. Left: WM793 and WM793-Res; Right: M238 and M238-Res. X axis, treatment conditions. Y axis, mean relative Bim-EL (normalized against DMSO-treated parental cells) from three experiments using actin mRNA level as an internal control. Error bars represent standard deviations. (d) Same as (c) except Bmf mRNA levels were analyzed. *P<0.05, ***P<0.001, based on two-tail Student's t-test assuming unequal variance