Figure 2.

ABT-199-resistance is associated with the upregulation of Mcl-1 and Bcl-xL mRNA and increased MCL-1 protein stability. RNA was extracted from parental and ABT199-R SU-DHL-6 and OCl-LY-19 cells after culture in the absence of ABT-199 for 72 h. (a) Mcl-1, (b) Bcl-xL, and (c) Bcl-2 fold change was analyzed by qRT-PCR. RNA levels of parental cells were set to 1 for analysis (*P<0.04, **P<0.05). MCL-1 protein half-life was determined by treating parental and ABT199-R (d) SU-DHL-6 and (f) OCl-LY-19 cells with cycloheximide (10 μg/ml) for the indicated time, followed by immunoblotting. β-actin was used as the loading control. Data in e and g were quantified by ImageJ. The experiments from a to g are representative of three independent experiments