Aims and background: Although glioblastomas infiltrate diffusely into adjacent brain, it is difficult to unequivocally identify the solitary invading glioma cell. It is necessary to develop coculture models to study the motility of glioma cells, and to monitor the cellular morphology, movement direction, migration area and invasion rate.
Methods: Cerebral slices were cultured on Millicell-CM membrane inserts in a petri dish. The neuronal viability and organizational structure of the brain sections were well maintained by experimental verification. C6 cell clones with persistent enhanced green fluorescent protein (EGFP) expression were established. EGFP-expressing glioma cells were cultured to form aggregates, which were implanted on the brain slices. The invasion area and migration rates of C6 cells on brain slices were measured. We evaluated the invasion area and depth after C6 cells were treated with the Rac1 inhibitor NSC23766.
Results: We successfully established the glioma cell-brain slice coculture model. In coculture, the average migration rate of C6 glioma cells within brain slices reached 11.36-15.27 μm/hour. The polarity of C6 glioma cells was parallel to the white matter tracts after 7 days. The invasive ability of C6 cells (depth: 105.3 ± 10.3 μm) treated with NSC23766 was weakened compared with the control group (depth: 198 ± 9.2 μm) within the white matter of brain slices (t = 16.26, p<0.05).
Conclusions: We developed the model to analyze the invasion features of glioma cells. The significant suppression of glioma cell invasion by NSC23766 in brain slices indicates that anti-Rac1 treatment may represent an important future therapeutic strategy for glioblastoma.