Sawada Tatsuo, Kato Yoichiro, Kobayashi Makio
Department of Pathology, Tokyo Women's Medical University, 8-1 Kawadacho, Shinjuku-ku, Tokyo 162-8666, Japan.
Brain Tumor Pathol. 2007;24(2):81-4. doi: 10.1007/s10014-007-0216-2. Epub 2007 Nov 28.
Cerebral edema is associated with common brain tumors. Aquaporine-4 (AQP4) is a member of the water channel protein family, which is thought to be a major factor regulating cerebral edema. To elucidate the characterization of the expression of AQP4 and the relationship of the expression of VEGF, we investigated the expression of AQP4 in tumors of the central nervous system immunohistochemically. Brain tumors and nontumorous cerebral tissue for control were evaluated by immunohistochemical staining using anti-AQP4, VEGF, CD34, and MIB-1. In tumor cells, only glial tumor cells showed a positive reaction for AQP4. The reactivities for immunostaining increased according to WHO grades. Reactive glial cells in edematous tissue also showed positive reactions. Although endothelial cells were negative and/or weakly positive for AQP4, the positive relationship suggested the expression of VEGF in endothelial cells in neovasculature and that of AQP 4 in tumor cells. APQ4 expression increased in human astrocytic tumors and edematous cerebral tissue. Upregulation of APQ4 by tumor cells and reactive astroglia were major factors of cerebral edema.
脑水肿与常见脑肿瘤相关。水通道蛋白4（AQP4）是水通道蛋白家族的成员，被认为是调节脑水肿的主要因素。为了阐明AQP4表达的特征以及VEGF表达之间的关系，我们采用免疫组织化学方法研究了中枢神经系统肿瘤中AQP4的表达。使用抗AQP4、VEGF、CD34和MIB-1抗体对脑肿瘤和作为对照的非肿瘤脑组织进行免疫组织化学染色评估。在肿瘤细胞中，只有神经胶质瘤细胞对AQP4呈阳性反应。免疫染色反应性根据世界卫生组织分级增加。水肿组织中的反应性胶质细胞也呈阳性反应。虽然内皮细胞对AQP4呈阴性和/或弱阳性，但这种正相关关系提示新生血管中内皮细胞VEGF的表达与肿瘤细胞中AQP4的表达有关。AQP4在人类星形细胞瘤和脑水肿脑组织中表达增加。肿瘤细胞和反应性星形胶质细胞上调AQP4是脑水肿的主要因素。
