Fig. 4

Soluble factors from microglia increase GBM proliferation but significantly inhibit GBM12 invasion. a Significant increase in MTT fold change at day 3 in GBM12 cells co-cultured with MG compared to GBM12 single cultures (both n = 3). b Representative images of spheroid-based invasion assay for GBM12 single cultures and GBM12-microglia co-cultures. Scale: 200 μm. c Quantification of GBM cell invasion in the presence or absence of soluble signals from microglia, with results reported as the mean radius of the invasion front of GBM cells versus the starting radius of the spheroid. GBM12 cells exhibited significantly decreased invasion (n = 8) in response to co-culture with HMC3 microglia (vs. GBM12 alone; n = 10). *p < 0.05, **p < 0.01, ****p < 0.0001