经胎盘诱发大鼠脑肿瘤不同阶段p53表达的研究

Series of Observation of p53 Protein Expression in ENA-INDUCED Brain Tumors of Rats

目的 :利用亚硝基乙基脲 (ENU)经胎盘诱发大鼠脑肿瘤的模型 ,对肿瘤发生前、后各个阶段的p5 3基因的变化进行连续地观察和研究。方法 :①取孕 17d大鼠 ,腹腔注射NEU(80mg kg)建立子代鼠脑肿瘤模型 ;②应用免疫组化的方法 ,对子代鼠 6 0d、90d、12 0d和 15 0d鼠脑p5 3蛋白表达进行观察。结果 :子代鼠出生后 6 0d、90d、12 0d和 15 0d ,特别是 6 0d和 90d组 ,异常p5 3蛋白的表达增加 ,肿瘤内与瘤周组织织间差异有统计学意义。结论 :异常p5 3蛋白的表达存在于肿瘤发生前、发生早期及发生后各阶段 ,进一步说明p5 3基因突变及其表达产物功能缺乏是脑胶质瘤起源的重要原因。p5 3基因的功能失常仅可能是导致基因链活动紊乱的因素之一 ,而肿瘤的形成还可能需要其他因素点燃。

Objective A series of p53 protein expression was observed on the transplacent induced brain tumor with ENU in rat to study the relationship of p53 gene and glioma.Methods (1)The animal model was established by transplacentally exposing fetal rats to carcinogen with intraperitoneally injecting one dose of N Nitroso ethylurea(NEU,80 mg/kg)into 17 day pregnant rats;(2)The p53 protein was examined with immunohistochemistry stain in the brain slices of offspring rats at their 60,90,120,and 150 day after birth.Results The altered p53 protein over expression exists in all the groups,especially in the 60 and 90 day groups.There were statistically significant differences between intra tumor tissues and tumor surrounding tissues.Conclusions As this model provided basis of different stages of tumor developing,Altered p53 ecists in the early events in tumorigenesis and may be one of the factors related to the dysfunction of gene chains.