p16蛋白与星形细胞瘤生物学行为的相关性研究

Study on the relationship between protein p16 and biological behavior in supratentorial astrocytoma

目的：探讨p16蛋白与人脑星形细胞瘤生物学行为的相关性。方法：采用免疫组织化学技术检测62例星形细胞瘤标本中p16、Rb、cyclinD1基因产物及Ki－67抗原的表达情况，探讨P16－cyclinDl／CDK4-pRb细胞周期调控通路的调控机制和p16蛋白与星形细胞瘤生物学行为的相关性。结果：（1）星形细胞瘤中pl6－cyclinD1／CDK4-pRb细胞周期调控通路存在异常调节和表达，以单个异常为主，占64.52％（40/62）。（2）p16蛋白表达缺失率为43、55％（27／62），恶性组（WHOⅢ－Ⅳ级）为65.63％（21／32），随病理分级的增高，缺失率增加（P＜0．001）；p16蛋白表达缺失者有较高的增殖标记指数（r＝－026，P＜0．05）；p16蛋白表达与KPS评分呈正相关（r=0．44，P＜0．001）。结论：p16、Rb、cyclinD1基因产物的异常表达和调节，尤其是p16蛋白缺失与星形细胞瘤发生发展密切相关，是反映星形细胞瘤恶性生物学行为的重要分子标志物之一。

Objective: To study the relationship between protein p16 and biological behavior in suptatentorial astrocytoma. Metheds: The p16, cyclinDl, Rb gene Products were detected in 62 astrocytomas and 7 normal brain tissues by immunohistochemical assay. Results: The absence of the p16 or pRb or the overexpression of cyclincl most often occurred in singular and in distinct lesions. The p16 gene products were immunohistochemically negative in 27 of 62(43. 55% ) astrocytonas, in which the most malignannt groups (WHO grade Ⅲ-Ⅳ) showed higher absence rate of the p16 gene products expression was frequent in high grade lesions, There was a negative Condation between the p16 gene products and grade, pRb. CyclinDI. Ki-67LI,and a positive correation with KPS score. Conclusions: The abnormal express and regulation of pl6, Rb, cyclinl genes, especially the deletions of the pl6 gene products in astrocytomas involved the alternative mechanisms for the tumor progression and the later might be one of the important molecular marker for malignant biological behavior of astrocytomas.