β-catenin expression in glioma with reference to autigenesis

据报道，β-连环蛋白具有多种功能，不仅与细胞粘附有关，而且与肿瘤发生和细胞极性有关。血管生成被认为在恶性脑肿瘤的发展中起重要作用。本研究从细胞粘附分子的角度探讨β-catenin与脑肿瘤血管增生的关系，并对45例N-乙基-N-亚硝基脲诱导的大鼠脑胶质瘤和32例人脑胶质母细胞瘤进行了β-catenin的免疫组化分析。结果表明，β-catenin在所有正常脑组织中均集中分布于血管细胞间连接处和血管腔内表面。相反，肿瘤中增殖的VC在细胞质中均匀染色，有或没有核。用核组成区相关嗜银蛋白（AgNOR）评价的VCs增殖能力在各型肿瘤中均高于正常脑组织，且基本上在正常脑组织中。 ...更多信息 与肿瘤的增殖潜能相关。因此，β-catenin的异常定位可能与VC通过获得血管增殖和细胞极性丧失而发生的剧烈转化有关。体外研究发现，牛主动脉内皮细胞（BAECs）在玻片上培养时，β-catenin在细胞间连接处基本呈斑点状。然而，当用纤连蛋白包被的载玻片诱导毛细血管样形成时，BAEC在胞质中被β-连环蛋白均匀且强烈地染色。与C6胶质瘤细胞条件培养基共同培养的BAECs中，与对照组相比，有更多的毛细血管样结构形成，AgNOR检测显示BAECs增殖能力明显增强。这些结果被认为支持了与体内结果一致的β-连环蛋白可能与脑肿瘤血管生成相关的假设。少

β-catenin is reported to have multiple functions associated with not only cell adhesion but also tumorigenesity and cell polarity. Angiogenesis is considered to play an important role in the development of malignant brain tumors. In this study, we researched the concerning of β-catenin to the vascular proliferation in brain tumors from the point of view of the cell adhesion molecules.We performed immunohistochemical analyses of β-catenin in 45 cases of N-ethyl-N-nitrosourea induced rat gliomas and 32 cases of glioblastomas in human. As a result, β-catenin was found concentrated in the vascular cell-cell junction and internal surface of the vascular lumen in all the normal brains. In contrast, proliferating VCs in tumors were stained homogeneously in the cytoplasm with or without nucleus. The proliferative potential of VCs evaluated by nuclear organizer region-associated argyrophilic protein (AgNOR) was higher in all types of the tumors than in the normal brains, and was basically in pa … More rallel with the proliferative potential of the tumors. Thus, the aberrant localization of β-catenin may be associated with vigorous transformation of VCs through acquisition of the vascular proliferation and loss of cell polarity in VCs. It was considered that β-catenin might be a possible regulator of angiogenesis in brain tumors.In vitro study, when bovine aortic endothelial cells (BAECs) were cultured in a slide, β-catenin was basically speckled at cell-cell junction. However, when the slide coated with fibronectin induced capillary like formations, BAECs were homogeneously and intensely stained for β-catenin in the cytoplasm. Subsequently, when BAECs were cultured with condition medium of rat C6 glioma cells, more capillary like formations and higher proliferative potential evaluated by AgNOR were observed compared with control group. These results were considered to support the hypothesis that β-catenin might be associated with the angiogenesis in brain tumors in accordance with in vivo results. Less