Figure 4.

Glioblastoma multiforme (GBM) cells show higher sensitivity to SapC-DOPS and increased levels of PtdSer in hypoxia. (a) X12v2 or Gli36ΔEGFR cells were treated with the indicated doses of SapC-DOPS in normoxia (20% O₂) or hypoxia (1% O₂) for 72 hours and cell viability was measured by MTT. All values were normalized to untreated control cells in normoxia or hypoxia. Data shown are mean ± SD of percentage viable cells after treatment with SapC-DOPS in normoxia and hypoxia, **P < 0.01. (b) PtdSer exposure was measured by flow cytometry using Annexin V-Pacific Blue following 72 hours of normoxia or hypoxia. MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; PtdSer, phosphatidylserine; SapC-DOPS, Saposin C-dioleoylphosphatidylserine.