超短期低剂量伽玛刀照射对胶质瘤细胞侵袭性的影响

Effect of ultra short-term low-dose irradiation on invasive properties of glioma cells： an in vitro study

目的 从基因水平验证低剂量伽玛刀照射在超短期内对胶质瘤细胞侵袭性的影响.方法 以80％等剂量线包绕U87、U251细胞系,分别以4、6、8、10Gy边缘剂量行伽玛刀照射30min,以未照射的细胞作为对照组.应用RT-PCR检测细胞β-链蛋白（β-catenin）、T细胞因子4（TCF-4）、蛋白激酶B（AKT）-1、AKT-2 mRNA的表达. 结果 与对照组比较,U87、U251细胞β-catenin、TCF-4、AKT-1和U87细胞AKT-2 mRNA的表达在4、6、8Gy伽玛刀照射后明显上调,10Gy照射后下调;U251细胞AKT-2 mRNA的表达在4、6Gy伽玛刀照射后明显上调,8、10 Gy照射后下调,差异均有统计学意义（P＜0.05）.其中U87细胞β-catenin、AKT-1 mRNA和U251细胞TCF-4、AKT-1、AKT-2 mRNA在6Gy照射时上调最明显,U87细胞TCF-4、AKT-2 mRNA和U251细胞β-catenin mRNA在8Gy照射时上调最明显. 结论 低剂量的伽玛刀照射对胶质瘤细胞的侵袭性在照射后30 min即有明显的促进作用.

Objective To evaluate the effect of ultra short-term low-dose gamma knife radiation on invasive properties of glioma cells at the genetic level.Methods Malignant glioma cell lines U87 and U251 were treated with gamma knife radiation,respectively,with a marginal doses of 0,4,6,8 and 10 Gy （all to the 80% isodose line）.Real time-PCR was used to measure the mRNA expressions of AKT-1,AKT-2,β-catenin and TCF-4 at 30 min after radiation.Results The expressions of AKT-1,AKT-2,β-catenin,TCF-4 in glioma cell lines after low-dose gamma knife radiation with a marginal dose of 6-8 Gy were significantly increased as compared with those after 0 Gy （P〈0.05）; reduced expressions ofAKT-1,AKT-2,β-catenin and TCF-4 after a marginal dose of 10 Gy were found as compared with those after 0 Gy （P〈0.05）; the β-catenin and AKT-1 mRNA expressions in U87 cells and TCF-4,AKT-1 and AKT-2 mRNA expressions in U251 cells enjoyed the most obvious increase at a marginal dose of 6 Gy; the TCF-4 and AKT-2 mRNA expressions in U87 cells and β-catenin mRNA expression in U251 cells enjoyed the most obvious increase at a marginal dose of 8 Gy.Conclusion Low-dose gamma knife radiation （6-8 Gy） could increase the β-catenin,TCF-4,AKT-1 and AKT-2 expressions,while high dose （10 Gy） could inhibit these effects in a short time period of 30 min.