Effects of siRNA specific to the protein kinase CK2αon apoptosis of laryngeal carcinoma cells

Background The relationship between apoptosis and tumors is a major focus in cancer research.RNA interference (RNAi) technology has emerged as a very potent tool to generate cellular knockdown phenotypes of a desired gene.The aim of this study was to explore the effect of siRNA specific to the protein casein kinase 2α(CK2α) on apoptosis of laryngeal carcinoma cells and to explore possible mechanisms. Methods An siRNA expression plasmid specific to CK2α,psiRNA-hH1 neo-CK2α,and a non-specific siRNA expression plasmid,psiRNA-hH1neo-cont,were constructed and transfected into Hep-2 cells by a lipofectamine method.The mRNA and protein levels of CK2αin transfected cells were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting analysis.Apoptosis was measured by Annexin V-fluorescein isothiocyanate(FITC)/ propidium iodide(PI) double-staining methods.The morphological changes to Hep-2 cells were observed under transmission electron microscopy(TEM).The levels of Bcl-2 and Bax proteins were measured by Western blotting analysis. Results Levels of CK2αmRNA and protein were significantly decreased in the psiRNA-hH1neo-CK2αgroup compared to the other groups(P<0.05).The apoptotic rate of the psiRNA-hH1neo-CK2αtransfected group was significantly higher compared to that in the untransfected group and the siRNA-hH1neo-cont transfected group(25.66%±0.83%, 3.66%±0.43%,and 5.18%±0.22%)(P <0.05).Compared with the untransfected group and the siRNA-hH1neo-cont transfected group,the psiRNA-hH1neo-CK2αtransfected group presented with classical ultrastructural features of apoptosis,such as karyopyknosis,chromatic agglutination adjacent to the nuclear membrane,and apoptotic bodies. Compared with the other two groups,the level of Bcl-2 protein in the psiRNA-hH1neo-CK2αtransfected group was decreased(0.20±0.09 vs.0.72±0.16,0.56±0.11,P<0.01),while the Bax protein level was increased(0.81±0.17 vs. 0.26±0.12,0.33±0.17,P<0.01) and the ratio of Bcl-2 to Bax was decreased(0.25±0.05 vs.2.76±0.21,1.70±0.22,P<0.01). Conclusions The siRNA expression plasmid specific to CK2αcould suppress CK2αexpression and induce the apoptosis of laryngeal carcinoma cells.This is possibly by decreasing the Bcl-2/Bax ratio.CK2αmay provide a potential therapeutic target against human laryngeal carcinoma.