水通道蛋白1在人成血管母细胞瘤中的表达与分布变化

目的 探讨人成血管母细胞瘤水通道蛋白I(AQP1)的表达变化在肿瘤发展过程中的病理生理意义. 方法 将自1980年至2005年我科收治的26例成血管母细胞瘤患者分为两组:实体肿瘤组与囊性肿瘤组,采用免疫组织化学方法 检测AQPl在成血管母细胞瘤的表达状况,RT-PCR方法 分析成血管母细胞瘤AQP1 mRNA的表达水平变化,激光共聚焦显微镜研究AQP1在血管内皮细胞及肿瘤细胞的表达分布关系.运用Western blot杂交分析AQP1蛋白在成血管母细胞瘤中的表达水平变化. 结果 免疫组织化学结果 显示,与正常脑组织相比,AQP1在成血管母细胞瘤中的表达水平明显升高,差异有统计学意义(P=0.002).在囊性成血管母细胞瘤中,AQP1的表达主要分布在肿瘤间质细胞膜上.在55.6%的实体成血管母细胞瘤中,肿瘤微血管内皮细胞上有AQP1的表达.仅44.4%的实体成血管母细胞瘤肿瘤间质细胞膜上有AQP1的表达.RT-PCR与Western blot杂交分析均表明.成血管母细胞瘤中AQP1 mRNA和蛋白的表达水平升高,且囊性成血管母细胞瘤中AOP1 mRNA和蛋白的表达水平明显高于实体性成血管母细胞瘤. 结论 AQP1表达的异常可能参与了人成血管母细胞瘤的形成与发展过程.同时,AQP1表达、分布的异常可能是人成血管母细胞瘤中瘤囊的形成与发展的重要病理生理机制.

Aquaporin-1 expression and distribution in human cerebellar hemangioblastomas

Objective To investigate the expression and distribution of aquaporin-1 (AQP1) in cerebellar hemangioblastomas and its relationship with cyst formation. Methods A retrospective analysis was conducted in 26 consecutive patients with solid or cystic cerebellar hemangioblastomas. Immunohistochemistry and double immunofluorescent microscopy were used to analyze the expression and distribution of AQP1 in the hemangioblastomas. RT-PCR and Western blotting were employed to detect AQP1 expression in the tumor tissue at the rnRNA and protein levels, respectively. The clinical data and the results of the laboratory examinations were analyzed using Fisher probabilities. Results Both cystic and solid hemangioblastornas showed up-regulated AQP1 expression as compared to the normal brain tissue (P=0.002). The cystic hemangioblastomas exhibited a different distribution pattern of AQP1 from the solid tumors, and in the former, AQP1 expression was found predominantly on the stromal cell membrane. In the solid hernangioblastomas, 55.6% showed positive AQP1 expression on the microvascular endothelial cells, and only 44.4% were positive for AQP1 expression on the strornal cells. Conclusion AQP1 expression is up-regulated in hemangioblastomas and its distribution differs between the tumors of different pathologies, suggesting the involvement of AQP1 in the pathophysiology of cyst formation in hemangioblastomas.