Protein Kinase CK2 Inhibition Down Modulates the NF-κB and STAT3 Survival Pathways, Enhances the Cellular Proteotoxic Stress and Synergistically Boosts the Cytotoxic Effect of Bortezomib on Multiple Myeloma and Mantle Cell Lymphoma Cells
Figure 6
RNA interference of CK2 in MM INA-6 cells modulates apoptosis and STAT3 phosphorylation.
(A) INA-6 cells were transfected with siGLO Green scrambled or siGLO Green plus CK2α and CK2βsiRNA oligos. 48h after transfection bortezomib 5 nM (BZ) was added to the cultures for 18h. Cells were collected 72h post-transfection. Apoptosis was evaluated through annexin V staining and FACS analysis on siGLO Green positive cells (A) and WB determination of the antiapoptotic markers Mcl1 and Bcl2 (B). In (A) histogram bars represent mean ± SEM of four independent experiments (left panel), while the cytometric histograms show the percentage of annexin V positive cells in a representative experiment (right panel). * indicates p<0.05. ♦ indicates p<0.05 between samples treated with bortezomib 5 nM alone and bortezomib 5 nM together with CK2 α.β siRNA. (B) STAT3 phosphorylation on Ser 727 (p-STAT3 Ser727, total STAT3, CK2α and CK2β levels were determined by WB in INA-6 tranfected with siGLO Green scrambled or siGLO Green plus CK2α and CK2βsiRNA oligos and treated with BZ for 18h. β-actin was used as a loading control.