EGFR、PTEN在常见恶性脑肿瘤中的表达及意义

目的探讨表皮生长因子受体（EGFR）和抑癌基因——人10号染色体上缺失的磷酸酶和张力蛋白类似物（PTEN）在常见恶性脑肿瘤中的表达及与脑肿瘤预后的关系。方法应用免疫组织化学SP法结合激光共聚焦免疫荧光显像法对多形性胶质母细胞瘤、髓母细胞瘤、间变性少突胶质细胞瘤和间变性室管膜瘤四种脑肿瘤，共计100例标本的EGFR和PTEN表达进行检测与分析。结果EGFR的阳性率在多形性胶质母细胞瘤、髓母细胞瘤、间变性少突胶质细胞瘤和间变性室管膜瘤中分别是76％（19／25），36％（9／25），28％（7／25）和24％（6／25）。PTEN的阴性率在上述四种肿瘤中为40％（10／25），8％（2／25），8％（2／25），4％（1／25）。PTEN阴性的多形性胶质母细胞瘤患者平均生存时间为7个月，PTEN阳性的患者平均生存时间为18个月。两组患者生存时间差异有统计学意义（P〈0．05）。结论EGFR的过表达和PTEN的缺失在多形性胶质母细胞瘤中常见，并和预后关系密切。但是，在髓母细胞瘤、间变性少突胶质细胞瘤和间变性室管膜瘤中EGFR的过表达和PTEN的缺失不常见。因此针对EGFR和PTEN的靶向治疗在多形性胶质母细胞瘤中有意义，而在其他三种肿瘤中不实用。

Expression of Epidermal Growth Factor Receptor and PTEN in Malignancy Brain Tumors

Objective To detect and analysis epidermal growth factor receptor (EGFR) and phosphatase and tensin homolog deleted on chromosome ten (PTEN) in different malignancy brain tumors, and to evaluate their prognostic significance. Methods Using immunohistochemistry to detect the expression of EGFR and PTEN and adopting confocal technology to verify their location in the specimens of 25 respectively glioblastoma multiformes, medulloblastomas, anaplastic oligodendrogliomas, and anaplastic ependymomas. Results 76% of glioblastoma multiformes had amplification of EGFR, and 40% of which lost PTEN. Patients with these phenomena had a poor survival prognosis, 7 months VS 18 months. However amplification of EGFR and deletion of PTEN were relatively low in other malignancy brain tumors. They were 36% and 8% in medulloblastomas, and 28% and 8% in anaplastic oligodendrogliomas, and 24% and 4% in anaplastic ependymomas. Conclusions PTEN mutation and EGFR amplification are important prognostic factors in patients with glioblastoma multiformes. PTEN mutation and EGFR overexpression are rare in medulloblastoma, anaplastic oligodendroglioma, and anaplastic ependymoma,so the EGFR or PTEN targeted antitumor approaches may be useful in glioblastoma multiformes but the other 3 tumors.