低氧环境下转染Ang-1对胃癌细胞凋亡的影响

Effects of angiopoietin-1 on apoptosis of human gastric cancer cell line under hypoxia

目的探讨在低氧环境下将促血管生成素1(Ang-1)转染到人胃癌细胞BGC-823中,检测其对人胃癌细胞凋亡的影响。方法利用腺病毒作为载体将已构建成功的Ang-1基因的重组腺病毒瞬时转染人胃癌细胞株BGC-823。实验分为对照组(未转染Ang-1的正常胃癌细胞)、低氧组(仅以低氧诱导剂氯化钴进行低氧干预)、转染组(仅以Ang-1转染)和低氧转染组(低氧干预加Ang-1转染)。通过流式细胞术检测转染各组凋亡率的改变,再分别使用半定量RT-PCR和Western blot方法检测上述各组Bcl-2和Bax mRNA和蛋白表达水平。结果与对照组、低氧组和转染组比较,低氧转染组胃癌细胞凋亡率明显下降(P<0.01);Bcl-2 mRNA和蛋白表达水平明显增加,BaxmRNA和蛋白水平明显减少(P<0.05)。结论低氧环境下转染Ang-1能够明显上调人胃癌细胞Bcl-2的表达,下调Bax的表达。这可能是其抑制细胞凋亡的机制之一。

Objective To evaluate the effects of angiopoietin-1（Ang-1） on cell apoptosis of human gastric cancer cell line BGC-823 under hypoxia.Methods BGC-823 cells were transfected with Ad-Ang-1 transiently under hypoxia induced by nimic cobalt chloride（group A）.The BGC-823 cells,which were not transfected but were under hypoxia（group B）,or transfected with Ad-Ang-1 without hypoxia（group C）,or were not transfected（group D）,were taken as the controls.The apoptosis rate was examined by flow cytometry and expressions of Bcl-2 and Bax mRNA and proteins were detected by semiquantitative RT-PCR and Western blot.Results Compared to groups of B,C and D,the apoptosis rate was lower（P0.01）,the expression of Bcl-2 mRNA and proteins was higher,while the expression of Bax mRNA and proteins was lower in group A（P0.05）.Conclusion Under hypoxia,transfection of Ang-1 into human gastric cancer line BGC-823 can significantly up-regulate Bcl-2 and down-regulate Bax expressions,which may be one of the mechanisms for inhibiting apoptosis.