榄香烯乳对人肺腺癌A549细胞放射敏感性影响及其机制的研究

目的 探讨榄香烯乳对人肺腺癌A549细胞放射敏感性的影响及其分子机制。方法 克隆形成实验检测10、20 μg/ml榄香烯乳对人肺腺癌A549细胞的放射敏感性影响。细胞分为空白对照组、单纯照射组(4 Gy X射线照射)、单纯药物组(给予10、20 μg/ml榄香烯乳);联合照射组(给予10、20 μg/ml 榄香烯乳24 h后4 Gy X射线照射)。Western blot检测DNA-PKcs、Bcl-2及P53蛋白的表达变化,并分析DNA-PKcs与Bcl-2、P53表达之间的相关性。结果 10 μg/ml榄香烯乳的放射增敏比SER_D0、SER_Dq 为1.54±0.20和1.43±0.15;20 μg/ml榄香烯乳SER_D0、SER_Dq 为1.63±0.32及1.75±0.19。与单纯照射组相比,10、20 μg/ml榄香烯乳联合照射组细胞的DNA-PKcs蛋白表达明显减少(t=7.52、8.33, P<0.05),Bcl-2蛋白表达明显减少(t=10.74、11.33, P<0.05),P53蛋白表达明显增加(t=-9.25、-7.66P<0.05)。DNA-PKcs与P53蛋白表达显著负相关(r=-0.569,P<0.05),与 Bcl-2蛋白表达显著正相关(r=0.755, P<0.05)。结论 榄香烯乳可增加人肺腺癌A549细胞的放射敏感性,其机制与下调DNA-PKcs表达抑制DNA双链损伤修复和上调p53,下调Bcl-2表达促进细胞凋亡有关。

Effect of elemene on radiosensitivity of A549 cells and its possible molecular mechanism

Objective To investigate the effect of elemene on the radiosensitivity of A549 cells and its possible molecular mechanism.Methods The effect of radiosensitivity was detected by colony forming assay.The protein expressions of DNA-PKcs,Bcl-2 and P53 were detected with Western blot.The correlation between the protein expression of DNA-PKcs and Bcl-2,DNA-PKcs and P53 was analyzed.Results Elemene had radiosensitizing effect on A549 cells,with the SERDo and SERDq 1.54 ± 0.20 and 1.43±0.15,respectively for 10 μg/ml elemene,and 1.63 ±0.32 and 1.75 ±0.19,respectively for 20 μg/ml elemene.Compared with irradiation group,the expression of DNA-PKcs was reduced significantly in 10,20 μg/ml elemene combined with radiation group ( t =7.52,8.33,P ＜ 0.05 ),so was for Bcl-2(t =10.74,11.33,P ＜0.05).The expression of P53 protein increased significantly (t =-9.25,7.66,P ＜0.05).There was a remarkable negative correlation between the expression of DNA-PKcs and P53(r =-0.569,P ＜0.05),and a remarkable positive correlation between DNA-PKcs and Bcl-2 (r =0.755,P ＜0.05 ).Conclusions Elemene has radiosensitizing effect on A549 cells,which might be related to down-regulation of DNA-PKcs gene expression,up-regulation of P53 and down-regulation of Bcl-2.