Quantitative Study of Invasiveness of Malignant Gliomas

目前，恶性胶质瘤的治疗仍然很困难，主要是由于肿瘤侵袭性生长到周围的正常脑组织。为了阐明神经胶质瘤的侵袭性，我们研究了神经组织中一种细胞黏附分子N-钙粘蛋白，它负责细胞与细胞之间的黏附。本研究探讨了N-钙粘蛋白在大鼠脑胶质瘤细胞系9L、C6、RG12中的表达与体外细胞聚集实验评价细胞黏附程度的相关性。在Northern印迹分析中，在三种大鼠胶质瘤细胞系中都发现了三种不同大小的N-钙粘蛋白转录本，而在正常脑组织中只有两种大小的条带。这三条带的表达程度随每条带的大小以及细胞系的不同而不同。尤其是最大的一条带(5.2Kb)的表达程度差异较大，在RG12中强，在9L中弱，在C6中弱，并且表达程度与体外细胞聚集实验所估计的黏附程度有关。这些结果提示N-钙粘蛋白在胶质瘤细胞的细胞间黏附中起作用，并参与胶质瘤的侵袭。

At presnt, it is still difficult to cure patients with malignant glial tumors, mainly because of invasive growth into surrounding normal brain tissue. To clarify the invasion of glial tumors, we studied one of the cell adhesion molecules, N-cadherin, which is responsible for cell-cell adhesion in neural tissue. In this study, we investigated the correlation between expression of N-cadherin mRNA in rat glioma cell lines 9L,C6, RG12 and the extent of adhesion of these cells evaluated by in vitro cell aggregation assay. In Northern blot analysis, three different sizes of N-cadherin transcripts were identified in all three rat glioma cell lines, wheres only two sizes of bands were recognized in normal brain tissue. The degree of expression of these three bands varied amang each band size as well as each cell line. Especially, the degree of expression of the largest band (5.2Kb) varied considerably, strong in RG12, medium in 9L and weak in C6, and the degree of expression was related to the extent of adhesion of these cell lines estimated by in vitro cell aggregation assay. These results suggest that N-cadherin plays a role in cell-cell adhesion in glioma cells, and is involved in the invasion of glial tumors.