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

<p>Synergistic effect of K27 and bortezomib (BZ in the figure) (A, C, E, G) or CX-4945 and bortezomib (B, D, F, H) on U-266 (A, B), INA-6 (C, D), Jeko-1 (E, F) and Rec-1 (G, H) cell proliferation. Left graphs: dose-response curve of cells incubated for 48 hours with increasing concentrations of K27 or CX-4945 (grey squared curve). Right graphs: dose-response curve of cells incubated for 48 hours with increasing concentrations of bortezomib alone (black squared curve) or K27 or CX-4945 plus bortezomib (black triangle curve). Cell proliferation was assessed by ³H-thymidine-incorporation assay. IC₅₀ for K27 was 6.98 µM and for bortezomib 2.16 nM in U-266; 3.77 µM for K27 and 3.18 nM for bortezomib in INA-6 cells; 4.43 µM for K27 and 4.65 nM for bortezomib in Jeko-1 cells and 3.13 µM for K27 and 11.06 nM in Rec-1 cells. IC50 of CX-4945 was 19.8 µM in U-266, 2.42 µM in INA-6, 2.4 µM in Jeko-1 and 1.46 µM in Rec-1 cells. The CI between K27 and bortezomib was calculated as to be 0.43 for U-266, 0.84 for INA-6, 0.16 for Jeko-1 and 0.5 for Rec-1. The CI between CX-4945 and bortezomib was calculated as to be 0.77 for U-266, 0.05 for INA-6, 0.016 for Jeko-1 and 0.69 for Rec-1.