Figure 4

Mifepristone adversely affects primary human VS cells and human-derived arachnoid cells in culture, but leaves primary human Schwann cells unaffected. (a) Metabolic activity of primary VS cells declines with increasing concentrations of mifepristone; individual data points represent metabolic activity as percentage of vehicle-treated control for ten individual tumors, performed in replicates of 3–5 wells per condition (vehicle-treated cells versus 35 μM mifepristone-treated cells, p = 0.002; **p < 0.01). (b) Quantification of the significant decline in BrdU incorporation observed in primary VS cells treated with 35 μM mifepristone (p = 0.0002; ***p < 0.001). (c–e) Live cell fluorescence microscopy reveals a significant increase in cytotoxicity of VS cells under mifepristone treatment; representative data from a single tumor, quantified from nine replicate images per treated well, performed in quadruplicate for each treatment condition: (c) Primary human VS cells imaged at 10X after treatment with 35 μM mifepristone for 72 hours, where cytotoxicity is indicated via green fluorescent signal; (d) Vehicle-treated control cells (DMSO 0.1%); (e) Quantification of cytotoxicity, reported as number of green objects per well after thresholding to exclude small cellular debris. (f) Mifepristone reduces the metabolic viability of schwannoma cells more significantly than that of AC-CRISPR NF2(−/−) and AC-CRISPR NF2(+/+) human arachnoid cells. (g) Mifepristone does not adversely affect the metabolic viability of primary human Schwann cells in culture (n = 8, p = 0.23). Center values in histograms are means; error bars are s.e.m.