Interactions between human glioma cells and fetal rat brain aggregates studied in a chemically defined medium

The in vitro invasive growth of two continuous human glioma cell lines (D-54Mg and GaMg) into aggregates of fetal rat brain cells is described. The tumor cells were first cultured as multicellular tumor spheroids and thereafter cocultured with brain aggregates in medium agar cultures. Two different types of culture media were used for the propagation of spheroids and for coculture experiments: Dulbecco's modified Eagle's medium supplemented with 10% newborn calf serum, and Costar SF-X chemically defined hybridoma medium. Both cell lines showed invasive growth into brain tissue in both types of media. Apart from progressive destruction caused by the malignant cells, the brain aggregates maintained characteristics of neural tissue. One cell line (D-54Mg) showed reduced invasiveness in chemically defined medium as measured with a grading system to quantify invasion. The coculture system may represent a basis for studying invasion of human glioma cells in brain tissue under defined chemical conditions.