CK2 inhibition induces apoptosis of CLL cells. Primary CLL cells were cultured for 48 hours in medium alone or with (A) 25μM TBB (n = 22) or (B) 25μM DRB (n = 17) and cell viability was evaluated after 48 hours. (C) CLL cells were incubated with the indicated doses of CX-4945 and viability was assessed at 48 hours. Results are representative of 5 patients analyzed. (D) CLL cells were incubated without or with TBB (12.5μM, 25μM) or DRB (12.5μM, 25μM) and viability was assessed at 24, 48, and 72 hours. Results are representative of 11 patients analyzed. (C-D) The percentage of live (bottom left), early apoptotic (bottom right), and late apoptotic/necrotic (top right) cells is indicated in the respective quadrants. (E-F) MEC1 cells were nucleofected with control (NT) or CK2α siRNA (CK2) and cultured for 72 hours. A total of 3 independent experiments are shown. (E) Cell lysates were immunoblotted with antibodies against CK2α or actin. (F) Viability of MEC1 nucleofected with control vs CK2α siRNA was analyzed at 72 hours. Results for each independent experiment are shown. (G) CLL cells were cultured with TBB (12.5μM, 25μM) for 24 and 48 hours. Cell lysates were immunoblotted with antibodies against caspase 3, PARP, or actin, as loading control. Results are representative of 3 patients analyzed. (H) CLL cells were preincubated with 20μM QVD-OPH for 1 hour and then cultured with 12.5μM TBB for 48 hours. Results are shown as mean ± SEM of triplicates and are representative of 3 patients analyzed. Cell viability was assessed by annexin V/7-AAD staining. Results are representative of 3 patients analyzed. (A-H) All evaluations of cell viability were performed by flow cytometric analysis after annexin V/7-AAD staining.