Mechanisms Of Autophagy In CK2 Inhibitor Induces Colon Cancer Cell Death

BackgroundColon cancer is a common malignant tumor of digestive system worldwide,which seriously endangers human health.Its morbidity and mortality are on the rise.Surgery and radiotherapy and chemotherapy are commonly used treatment methods.However,with the extensive use of drugs,obvious tolerance has emerged.Therefore,searching for new therapeutic targets for colon cancer has become a research hotspot.Studies have shown that casein kinase CK2 is involved in the occurrence and development of a variety of tumors,but its effect on the biological behavior of colon cancer cells and the possible role of autophagy in this process are still unclear.ObjectiveTo clarify the effect of CK2 inhibitor on the survival and apoptosis of colon cancer cells and to explore the role of autophagy in the cytotoxicity induced by CK2 inhibitor,provide new molecular targets and combined drug strategies for colon cancer.MethodsImmunohistochemistry was used to detect CK2α protein expression in clinical colon cancer and adjacent normal tissues.The relationship between CK2 a protein expression and clinicopathological characteristics was analyzed statistically.Western blotting was used to detect CK2 protein expression in clinical colon cancer and adjacent normal tissues.Different colon cancer cells(RKO,SW480,HCT116,LOVO)were cultured in vitro and treated with CK2 inhibitor TBB.CCK8 assay was used to detect the effect of TBB on the survival rate of colon cancer cells.Western blotting and kinase activity assay kit were used to analyze the expression level and activity changes of apoptosis-related protein caspase-3.Western blotting was used to detect the expression of autophagy-related proteins LC3 and P62.Combined with autophagy inhibitor 3-MA and chloroquine,CCK8 was used to detect the effect of combined action on cell viability.Western blotting was used to detect the expression level of caspase-3.Results1.Immunohistochemical results showed that the expression of CK2α in colon cancer tissues was significantly higher than that in adjacent normal tissues.The increase of CK2α expression was closely related to tumor size(T stage),lymph node metastasis(N stage)and differentiation(p < 0.05).2.Western blotting results showed that CK2α protein expression in colon cancer tissues was significantly higher than that in adjacent normal tissues(p < 0.05).3.CCK8 results showed that different concentrations of TBB could significantly reduce the survival rate of colon cancer cells(RKO,SW480,HCT116,LOVO),and the difference was statistically significant(p < 0.05).4.Western blotting showed that different concentrations of TBB could significantly increase cleaved caspase-3 expression in colon cancer cells RKO and HCT116(p < 0.05).5.The results of Caspase-3 activity test showed that compared with the control group,TBB without concentration could significantly increase the activity of Caspase-3 in cells,the difference was statistically significant(p < 0.05).6.CCK8 results showed that the combination of autophagy inhibitor 3-MA or chloroquine could further increase the TBB-induced decrease in the survival rate of RKO and HCT116 cells,with statistical significance(p < 0.05).7.Western blotting showed that the expression of cleaved caspase-3 in RKO and HCT116 cells induced by TBB could be further increased by combination of autophagy inhibitor 3-MA or chloroquine(p < 0.05).ConclusionCK2α expression is closely related to the pathological characteristics of clinical colon cancer.Inhibition of CK2 can significantly reduce the survival rate and increase apoptosis of colon cancer cells.Combination of autophagy inhibitors can further increase the cytotoxicity of CK2 inhibitors.The study provides a new strategy for the clinical treatment of colon cancer.