【摘要】 目的:研究低剂量辐射对裸鼠移植人胶质瘤U251细胞凋亡相关基因mRNA表达的影响。方法:35只荷人胶质瘤U251瘤裸小鼠,随机分为7个实验组,假照组:0 mGy;D1组:75 mGy;D2组:4 Gy;D1-12 h+D2组:D1照射后12 h予以D2;D1-24 h+D2组:D1照射后24 h予以D2;D1-48 h+D2组:D1照射后48 h时予以D2;D1-72 h+D2组:D1照射后72 h予以D2。每组5只。各实验组不同方式照射后4 d,荷瘤裸鼠全部处死,采用原位杂交技术检测荷瘤组织的p53、Bcl-2和Bax的mRNA表达水平。结果:D1(75 mGy)和D2(4 Gy)照射后,胶质瘤细胞的p53和Bax的mRNA表达分别呈上升趋势,Bcl-2的mRNA表达呈下降趋势,但与假照组比较,差异无显著性(P>0.05);D1+D2组(D1和D2间隔24、48及72 h)的p53和Bax的mRNA表达明显增多,Bcl-2 mRNA表达显著下降,与假照组比较差异有显著性(P<0.05或P<0.01)。结论:低剂量辐射在一定程度上可能上调了胶质瘤细胞的p53、Bax的mRNA表达,下调了Bcl-2mRNA的表达,同时对其后的大剂量辐射有协同作用。更多还原

【Abstract】 Objective To study the effects of low dose radiation（LDR）on expression of apoptosis-related gene mRNA of transplantation tumor tissues of human glioma（U251）-bearing nude mice.Methods Thirty-five tumor-bearing nude mice were divided into seven groups: sham-irradiated group:0 mGy;D₁ group:75 mGy;D₂ group:4 Gy;D₁-12 h+D₂ group:between D₁ and D₂ was 12 h;D₁-24 h+D₂ group:between D₁ and D₂ was 24 h;（D₁-48 h+）D₂ group:between D₁ and D₂ was 48 h;D₁-72 h+D₂ group:between D₁ and D₂ was 72 h.The expression of apoptosis-related gene mRNA of transplantation tumor tissues of tumor（U251）-bearing nude mice was detected by in situ hybridization.Results There were basal expressions of p53,Bcl-2,Bax mRNA in all groups.The transcription levels of p53 and Bax were slightly up-regulated and Bcl-2 was slightly down-regulated in D₁（75 mGy）group and D₂（4 Gy） group,but there was no significant difference compared with sham-irradiated group（0 mGy）（P>0.05）;While the differences of the levels of p53,Bcl2,Bax between all D₁+D₂ groups and sham-irradiated group were significant（P<0.05 or P<0.01）.Conclusion LDR could up-regulate the transcription level of p53,Bax and down-regulate Bcl-2 to some extent,and it maybe have synergic effect with high dose radiation.更多还原