Interaction between rat glioma cells and normal rat brain tissue in organ culture.

A system for coculture between normal rat brain fragments and multicellular spheroids of rat glioma cells is described. The tumor cells were derived from fetal BD IX rats treated transplacentally with the carcinogen N-ethyl-N-nitrosourea (CAS: 759-73-9). Brain fragments were obtained from fetal BD IX rats and precultured for 20 days before confrontation with multicellular tumor spheroids. The cocultures were grown in nonadherent stationary organ culture for 30 days. Due to morphologic similarities between normal brain cells and tumor cells, the tumor cells were labeled with tritiated thymidine, which made them easily recognizable in autoradiographs. The two structures adhered to each other, and glioma cells progressively invaded and replaced the normal brain tissue. Invasion and replacement are characteristic features of brain tumors in vivo. Therefore, this organotypic and syngeneic model may be useful for investigation of these phenomena outside the body.