【摘要】 目的　探讨X 刀治疗脑胶质瘤的最佳剂量—效应关系和最佳时间—效应关系。方法　以BT3 2 5细胞系为实验对象 ,设置了阴性对照组、5Gy、10Gy、15Gy、2 0Gy和 3 0Gy组 ,应用Varian直线加速器行单次大剂量照射 ,分别于 2h、6h、12h、4 8h、72h和 96h采用流式细胞仪观察细胞凋亡和细胞周期的改变 ;采用免疫组化法观察p5 3、BcL 2和PCNA基因的表达情况 ;采用光镜和电镜观察细胞凋亡的形态学改变。结果　X线诱导BT3 2 5细胞系凋亡的最佳剂量为 2 0Gy ,凋亡率为 66 95 %。BT3 2 5细胞受一定剂量X线照射后凋亡细胞逐渐增加 ,12～ 2 4h左右到平台 ,以后即使再增加剂量 ,细胞凋亡也不再增加。在 2 0Gy 4 8h时 ,p5 3基因表达最高 ,BcL 2基因表达明显减弱 ,PCNA 12h内阳性率较高 ,随着时间延长 ,其表达率明显下降 ,尤以 4 8h为著。且细胞周期发生G1 阻滞 ,达 85 5 6% ,此时经FCM检测细胞凋亡发生率也最高。结论　X线诱导细胞系凋亡存在最佳剂量—效应关系和最佳时间—效应关系 ,且与p5 3、BcL 2和PCNA基因的表达有一定的关系更多还原

【Abstract】 Objective To explore X knife therapeutic doses to induce glioma cell line (BT325) apoptosis and the optimal relationship between time and effect.Methods BT 325 cells were divided into 6 groups:5Gy、10Gy、15Gy、20Gy、30Gy and negative control.Varian Clinac 600C was used to radiate BT325 cells.After 2h、6h、12h、48h、72h and 96h,cell apoptosis and cell cycle were detected by Flow Cytometer (FCM) and morphological check.Immunohistochemistry(ABC) method was used to examine the expression of p53、BcL 2 and PCNA genes.Results The largest apoptotic rate,66.95%,was achieved 48h after 20Gy radiation.Apoptotic rate increased gradually after radiation and reached its peak 12～48h later.During 48h after 20Gy radiation,p53 expression reached its peak while BcL 2 expression significantly decreased.PCNA expression was higher at 24h than that at 48h.Around 85.56% cells were arrested at G 1 phase.Conclusion There was optimal relationship between dose effect and between time eftect in BT325 after X ray radiation.Gene expression of p53、BcL 2、PCNA were related to the radiobiological effect.更多还原