ABSTRACT
Objective To study the molecular mechanism of oridonin-induced apoptosis of ghoma SHG44 cells.Methods A growth curve was plotted using CCK-8 colorimetric method with different concentrations of oridonin (0,1.25,2.5,5,10,20,and 40 μmol/L)to observe its effect on the growth of SHG44 cells.Hoechst33258 and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were used to examine the changes in cell morphology and flow cytometry was used to detect cell apoptosis.Western blotting was used to analyze the expression of apoptosis-related proteins (Caspase-3,cleaved Caspase-3,Bax,and Bcl-2)in SHG44 cells.Results SHG44 cell proliferation was significantly suppressed after 24 and 48 h Oridonin treatment,with a half-maximal inhibitory concentration of 7.865 and 4.74 μmol/L,respectively.Hoechst33258 and TUNEL staining showed changes in cell morphology such as shrinkage and nucleus fragmentation and morphogenesis,which are indicative of apoptosis.Western blotting analysis showed that oridonin inhibited the expression of Bcl-2 and activated the expression of Caspase-3 and Bax.Conclusion Oridonin can inhibit the proliferation and induce the apoptosis of SHG44 cells by regulating the expression of apoptosis-related proteins.
ABSTRACT
Objective: To investigate the changes of radiosensitivity and the expression of cyclooxygenase 2 (COX-2) in the surviving progeny from the irradiated human glioma SHG-44 cells and to provide a theoretical basis for application of COX-2 inhibitors in clinic. Methods: Radiosensitivity of mother SHG-44 cells and that of surviving progeny from the irradiated human glioma SHG-44 cells were studied by measuring the colony-forming rate. The mRNA transcription and protein expression of COX-2 were detected by RT-PCR and immunohistochemical staining, respectively. Results: The radiosensitivity was decreased and the mRNA and protein expressions of COX-2 increased in the surviving progeny of the irradiated SHG-44 cells compared with mother SHG-44 cells. The expression levels of COX-2 were negatively correlated with the radiosensitivity in the irradiated SHG-44 cells. Conclusion: Radiation induced upregulation of COX-2 expression and downregulation of the radiosensitivity in the the surviving progeny from the irradiated human glioma SHG-44 cells. The elevated expression of COX-2 may be one of the reasons for the radioresistance of irradiated SHG-44 cells.