不同类型胶质瘤PTEN、P—Tyr蛋白表达差异及其临床意义

目的探讨PTEN蛋白及其作用底物P—Tyr在不同胶质瘤中的表达差异和临床意义。方法对69例胶质瘤（髓母细胞瘤34例；间变型或胶质母细胞瘤10例；室管膜瘤10例；纤维型或毛细胞型低级别星形细胞瘤15例；）进行PTEN和P—Tyr免疫组化染色，评价不同类型胶质瘤PTEN阳性表达率，半定量测定其平均染色强度IS（intensity score）。结果髓母细胞瘤、恶性胶质瘤、室管膜瘤和低级别星形细胞瘤的PTEN阳性表达率分别为：23．5％、20％、30％、80％；PTEN IS均值分别为（0．59±0．43）、（0．47±0．32）、（0．39±0．32）、（1．17±0．52）；P—Tyr的阳性表达率分别为91．2％、80％、90％、73．3％；P—Tyr IS的均值为（1．92±0．79）、（1．41±0．44）、（1．72±0．69）、（1．16±0．48）。髓母细胞瘤、恶性胶质瘤和低级别星形细胞瘤在PTEN阳性表达率和染色强度上存在明显差异（P〈0．01），所有胶质瘤的PTEN和P—Tyr染色强度IS呈负相关。结论PTEN表达缺失与肿瘤的生物学行为密切相关，系肿瘤恶性转化和肿瘤增殖活性增加的主要原因；PTEN与P—Tyr的表达呈负相关说明，PTEN具有蛋白酪氨酸磷酸酯酶活性，并起抑制肿瘤效应。

Significance and Different Expression of PTEN、 P- Tyr in Different Type Gliomas

Objective To investigate the clinical significance and different extent of PTEN and P -Tyr （phosphorylated tyrosine - substrate of PTEN protein phosphatase activity） protein expression in different type gliomas. Methods Immunohistochemical staining was used in 69 cases gliomas specimens （34 cases of medulloblastomas; 10 cases of anaplastia astrocytomas or glioblastomas; 10 cases of ependymomas;15 cases of fibra or pilocytic low- grade astrocytomas）to determine the protein expression of PTEN, P - Tyr , determine positive expression ratio of PTEN protein and staining intensity score. Results The positive expression ratio of PTEN protein in medulloblastoma,malignant gliomas, ependymoma ,low- grade astrocytoma were 23.5% ,20% ,30% ,80% respectively. Mean PTEN IS were（0. 59 ± 0. 43）, （0. 47 ± 0. 32）, （0. 39 ± 0. 32）, （ 1.17 ± 0. 52）respectively. The positive expression ratio of P - Tyr protein were 91.2% ,80% ,90% ,73.3% respectively. The significant difference was positive expression ratio and staining intensity between low- grade astrocytomas and medulloblastoma, malignant gliomas （P 〈 0. 01 ） . Conclusion Thess of PTEN functional protein dueing to gene mutation is an important course during the tumorigrnicity and development of gliomas ,it was association with biological behavior of gliomas, intensity score of PTEN and P - Tyr manifestated inverse correlation, PTEN protein posses protein phosphatases activity, yield to the tumor suppressor effect.