Cholesteryl ester transfer protein enhances the radiosensitivity of human cervical cancer HeLa cells / 肿瘤

ABSTRACT

Objective: To investigate the effect of cholesteryl ester transfer protein (CETP) on the radiosensitivity of human cervical cancer HeLa cells. Methods: HeLa-CETP cells with overexpression of CETP were established by stable transfection with pcDNA3 expression vector encoding a full-length of CETP gene. The HeLa cells which transfected with pcDNA3 empty vector were used as the control. The survival rate of HeLa-CETP cells was examined by clone formation assay. The apoptosis rate was detected by FCM. The expressions of apoptosis-related proteins Bax, Bcl-2 and nuclear factor-kappa B (NF-κB) were detected by Western blotting. Results: After X-ray radiation exposure, the sensitizing enhancement ratio (SER)D0 and SERDq of HeLa-CETP cells with overexpression of CETP were 1.42 and 2.09, respectively. There was no significant difference in the survival rate between the untransfected HeLa cells and the HeLa cells transfected with empty vector. FCM result showed that X-ray-induced apoptosis of HeLa-CETP cells was significantly higher than those of the untransfected HeLa cells and the HeLa cells transfected with empty vector (P<0.05). Moreover, the enhanced expression level of CETP could increase the expression of pro-apoptosis-related Bax protein and decrease the expressions of anti-apoptosis-related Bcl-2 and NF-κB proteins. Conclusion: Elevated expression of CETP by transfection with exogenous CETP gene can increase the radiation sensitivity of HeLa cells. This mechanism may be related to the increased radiation-induced apoptosis and the changes in the expression of apoptosis-related proteins. Copyright© 2011 by Tumor.