Figure 5.

Effect of MLN4924 on CDK inhibitors p21 and p27 in CLL cells. (a) CLL cells were co-cultured with CD40L-expressing stroma in the presence or not of 25 ng/ml IL-21 for 72 h. Thereafter, cells were treated with 0.05–1 μM MLN4924 or vehicle control, collected at the indicated time points and subjected to immunoblotting. Images representative of at least four independent experiments are shown. (b) CLL cells were transfected with the individual siRNAs against p21, p27 or control siRNA using Amaxa program X-05. Immediately after nucleofection, cells were cultured on CD40L-expressing stroma in the presence of 25 ng/ml IL-21 for 72 h, followed by incubation with 0.5 μM MLN4924 or vehicle control for 24 h. Whole-cell lysates were subjected to immunoblotting. Representative blots of three independent experiments are shown