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

采用大鼠脑组织器官型培养建立胶质瘤侵袭模型。将从2天大的新生大鼠制备的脑切片在空气和培养基之间的界面处保持在培养物中。将切片放置在由8 mm孔径的聚碳酸酯膜和0.4mm孔径的膜组成的双层膜上。培养脑片中的器官型细胞结构保持良好，而神经元活力保持完整超过两个月。当C6胶质瘤球体与脑片共培养时，肿瘤细胞以分散的方式在球体周围迁移。外源性L1或GMF-Ⅰ能强烈刺激细胞迁移，而纤维连接蛋白、腱生蛋白和GMF-Ⅱ则无明显作用。当放置在脑切片上的C6神经胶质瘤细胞在用L1转染的成纤维细胞刺激的同时孵育2天时，更多的肿瘤细胞侵入并到达上膜的底部。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。目前的入侵模型，它模仿了在体内条件下的中枢神经系统，可能使其有可能分析实际事件的胶质瘤细胞入侵正常脑原位。

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.