Effects of CK2 and proteasome inhibition on MM and MCL cell survival.

<p>Evaluation of apoptosis through WB analysis of PARP cleavage (CL PARP = Cleaved PARP) (A) in MM cells U-266, INA-6, INA-6 co-cultured with HS-5 (top panels), MCL cells Granta-519, Jeko-1 and Rec-1 (bottom panels); (B, C) annexin V staining and FACS analysis on INA-6 MM cells alone or in co-cultures with HS-5 (B), patient derived plasma cells (C) treated with the CK2 inhibitors CX-4945 (grey bars), the proteasome inhibitor bortezomib (BZ in the figure) at different concentrations (black bars) or the combination of the two compounds (grey striped bars) for 18 hours. In the case of INA-6 grown in co-colture with HS-5, experiments were performed by staining with APC-conjugated anti-CD45 antibody, which is expressed by INA-6 cells but not by stromal cells and with FITC-conjugated annexin V. In C, the apoptotic effect was measured by double staining with CD38 PE and annexin V-FITC. CD38⁺ bright cells were selected. Histogram bars represent mean ± SEM of three independent patient plasma cells (left panel), while the cytometric histograms show the percentage of annexin V positive cells in a representative experiment (right panel); (D) apoptosis of MCL cell lines Granta-519, Jeko-1, Rec-1 treated with the CK2 inhibitors CX-4945 (light grey bars), K27 (dark grey bars), the proteasome inhibitor bortezomib at different concentrations (black bars) or the combination of CX-4945 and bortezomib (grey dotted bars) or K27 and bortezomib (grey striped bars) for 18h. Data represent mean ± SEM of at least three independent experiments. * indicates p<0.05. In B ♦ indicates p<0.05 between samples treated with bortezomib 5 nM alone and bortezomib 5 nM together with CX-4945. In C • indicates p<0.05 between samples treated with bortezomib 2.5 nM alone and bortezomib 2.5 nM together with CX-4945. In D # indicates p<0.05 between samples treated with bortezomib alone and bortezomib together with CX-4945 or K27.