Establishment of glioma invasion model by using the three-dimensional brain organotypic culture

采用大鼠脑器官型培养建立脑胶质瘤侵袭模型。将2日龄大鼠新生脑切片置于空气与培养基的交界面培养。切片被放置在双层膜上，双层膜由8mm孔径的聚碳酸酯膜和0.4mm孔径的膜组成。当C6胶质瘤球体与脑切片共培养时，肿瘤细胞以分散的方式在球体周围迁移，在两个多月的时间内，脑切片的器官型细胞结构保持良好，神经元活力保持完整。外源性L1或GMF-I能强烈刺激细胞迁移，而纤维连接蛋白、腱素和GMF-II对细胞迁移的影响很小或没有影响。放置在脑切片上的C6胶质瘤细胞在l1转染的成纤维细胞刺激下孵育2天后，更多的肿瘤细胞侵入并到达上膜底部。这种l1刺激的胶质瘤细胞侵入脑切片被抗l1抗体显著抑制。目前的侵袭模型，模拟中枢神经系统的体内条件，可能使分析胶质瘤细胞在正常大脑原位侵袭的实际事件成为可能。

Glioma invasion model was established by using an organotypic culture of rat brains. Brain slices prepared from 2-day-old rat neonates were maintained in culture at the interface between air and the culture medium. The slices were placed on double-layred membranes consisting of an 8mm pore-size polycarbonate membrane and a 0.4mm pore-size membrane. The organotypic cytoarchitecture in cultured brain slices remained well preserved while the neuronal viability was kept intact for over two months When C6 glioma spheroids were cocultured with brain slices, the tumor cells migrated in a scattered fashion around the spheroids. The cell migration was strongly stimulated by exogenous L1 or GMF-I,while fibronectin, tenascin and GMF-II had little or no effect. When C6 glioma cells placed on the brain slices were incubated while being stimulated by L1-transfected fibroblast cells for 2 days, many more tumor cells invaded and reached the bottom of the upper membrane. This L1-stimulated glioma cell invasion into brain slices was significantly inhibited by an anti-L1 antibody. The present invasion model, which mimics the in vivo conditions of the CNS,may make it possible to analyze actual events of glioma cell invasion in normal brains in situ.