β-榄香烯对肾癌细胞的体外放射增敏作用

目的　探讨 β 榄香烯对肾癌细胞GRC 1的体外放射增敏作用及机理。 方法　将GRC 1细胞分为空白组 (加培养液 2mL)、空白乳组 (加空白乳培养液 2mL)和加药组 (加 5 0mg·L -1榄香烯乳培养液 2mL) ,培养 2 4h后 ,3组细胞悬液在剂量率 4 0 0cGy·min-1时 ,分别接受来自 6MeV直线加速器不同剂量的x线照射。计数被照细胞克隆群数 ,绘制细胞放射 存活曲线图。流式细胞仪检测各组细胞的周期变化与凋亡。对 3组爬片细胞进行免疫细胞化学染色 ,成像系统灰度分析bcl 2与PCNA基因表达。结果　流式细胞术显示 ,5 0mg·L -1榄香烯乳对肾癌细胞的G2 M阻滞作用随时间增加而增强 ,2 4h时作用达高峰 ;随时间和照射剂量的增加细胞凋亡水平增高。细胞爬片的成像系统灰度分析显示加药组与空白组相比 ,bcl 2基因表达降低 2 0 % ,而两组PCNA无表达。结论　β 榄香烯乳对肾癌细胞GRC 1有放射增敏作用 ,其作用机制可能与下调bcl 2基因表达 ,诱导GRC 1细胞凋亡和对细胞G2 M期阻滞有关

In vitro study on increase in radio sensitivity of renal cell carcinoma induced by β-elemenen

Objective To study the effect and mechanism of increase in radio sensitivity of kidney cancer cells(GRC-1) induced by β-elemenen in vitro. Methods GRC-1 cells were divided into 3 groups, blank group (added with 2 mL culture medium), emulsion group (added with 2 mL blank emulsion culture medium) and drug group (added with 2 mL 50 mg·L -1 β-elemenen culture medium). After been cultivated for 24 hours, the cells were irradiated using 6MeV X-linear accelerator in different doses at the rate of 400cGy per minute. Number of cell clones was counted, and radiation-survival curve of GRC-1 cells was drawn. Flow cytometry (FCM) was used to measure cell cycle and apoptosis. Cells of climbing flake were dyed by immunocytochemical method, the gene expression of bcl-2 and PCNA was measured by imaging system. Results The cell cycle showed that the G 2M blocking caused by 50 mg·L -1 β-elemenen was enhanced with time increase. It reached peak at 24 hours. FCM showed that the level of apoptosis increased with increase in drug dose and action time. The gene expression of bcl-2 was decreased by 20% in drug group than that in blank group, but there was no expression of PCNA in the two groups. Conclusion The radiosensitivity of GRC-1 cells can be enhanced by β-elemenen. The mechanism of effect may be associated with the cell cycle blocking, inducing cell apoptosis and down-regulating expression of bcl-2 gene.