星形细胞瘤中Mdm2、p53的表达及调控机制探讨

 目的　探讨不同组织病理分级的星形细胞瘤中Mdm2、p5 3的表达水平 ,并从蛋白质水平分析在肿瘤细胞中p5 3/Mdm2负反馈调节机制紊乱的原因。方法　采用免疫组织化学方法检测 6 8例星形细胞瘤标本中Mdm2和 p5 3的表达水平。 结果　星形细胞瘤中Mdm2和 p5 3的表达率分别是4 1.2 %( 2 8/ 6 8)和 4 5 .6 % ( 31/ 6 8) ,随着肿瘤恶性程度的增加 ,Mdm2、p5 3的表达率呈上升趋势 ,Spearman等级相关分析显示 ,Mdm2、p5 3的表达与肿瘤分级呈正相关。Mdm2表达和p5 3一致表达符合率达6 6 .2 %( 4 5 / 6 8) ,两者的表达密切相关 (P <0 .0 5 ) ,Spearman等级相关分析Mdm2表达与 p5 3表达呈正相关 (P<0 .0 1)。结论　Mdm2、p5 3的表达与星形细胞瘤组织病理分级呈正相关。Mdm2的表达与 p5 3的表达存在一致性 ,两者的联合表达是肿瘤高度恶性的生物学标志。

Study of the Expression and Regulation Mechanisms of Mdm2,p53 in Human Astrocytoma

Objective To study the incidence of PTEN, Mdm2 and p53 expression in different histopathological grades of astrocytoma and show the reason of the p53/Mdm2 auto regulatory feedback loop model is abnormal in tumor cell.Methods The surgical specimens from 68 brain astrocytoma patients were analysed to detect Mdm2 and p53 expression with immunohistochemical method.Results The incidence of Mdm2 and p53 expression was 41.2% (28/68) and 45.6% (31/68) respectively in astrocytoma. With the grade of astrocytoma increasing the levels of Mmd2, p53 protein increased. There was a positive correlation between Mdm2, p53 expression and grade of astrocytoma by using the Spearman Correlation test to analyse the data. 18 cases exhibited both Mdm2 and p53 positive expression and 27 cases exhibit both Mdm2 and p53 negative expression, so the incidence of simultaneous staining or no staining was 66.2% (45/68). In statistics, a positive correlation was found between Mdm2 and p53 expression.Conclusion There was a positive correlation between histopathological grades of astrocytoma and Mdm2 accumulation, p53 expression. Mdm2 accumulation was in accordance with p53 expression. Mdm2 and p53 co expression was the biological character of high grade tumor.