【摘要】 目的研究硼中子俘获疗法(BNCT)能否诱导体外培养的U251细胞发生凋亡,并探讨其诱导细胞凋亡的机制。方法采用四甲基偶氮唑蓝(MTT)法绘制细胞生长曲线,应用光镜、荧光显微镜、透射电子显微镜观察BNCT后细胞形态改变;使用流式细胞仪检测细胞凋亡率;利用细胞克隆形成实验分析细胞存活分数;用免疫组织化学方法检测相关蛋白表达的变化。结果在体外试验中BNCT对U251细胞的杀伤力强,并观察到了典型的细胞凋亡改变,4、8Gy照射后48h流式细胞仪检测,细胞凋亡率分别为60.2%、80.6%。在凋亡过程中,p53蛋白表达明显增高,而bc1-2蛋白表达下调。结论BNCT可诱导U251细胞发生凋亡,其机制可能与p53基因表达上调及bcl-2基因表达下调有关。更多还原

【Abstract】 Objective To investigate the induction effect of the boron neutron capture therapy (BNCT) on apoptosis of human brain glioma U251 cells in vitro and the possible mechanisms.Methods Methyl thiazolyl tetrazolium (MTT) assay was used to test the changes in the proliferation of U251 cells after irradiation. HE staining, Hoechst33342 fluorescence staining,transmission electron microscope (TEM) were applied to observe the changes of cell morphology.The Annexin V-fluorescein isothiocyanate (FITC)/ propidium iodide (PI) staining were applied to detect the apoptotic rate induced by BNCT by flow cytometer (FCM). Colony forming assay was used to calculate cell surviving fraction. The expression of p53 and bcl-2 protein was studied by immunocytochemistry.Results BNCT obviously suppressed the proliferation of U251 glioma cell. The apoptotic rates observed 48 h after irradiation was 60.2% and 80.6% for BNCT 4 Gy and 8 Gy. Immunocytochemistry showed BNCT promoted p53 protein expression, and at the same time it also inhibited bc1-2 expression.Conclusion BNCT can induce U251 apoptosis possibly by promoting p53 and inhibiting bcl-2 expression.更多还原