Figure 7

8MGBA glioblastoma proliferation and tumor incidence was not increased by AT-MSC. A. Proliferation of EGFP-8MGBA cells when admixed with increasing numbers of AT-MSC or maintained in AT-MSC conditioned low-serum medium was evaluated by relative fluorescence after 3 days. AT-MSC did not support tumor cell proliferation in comparison to control without AT-MSC. EGFP-8MGBA proliferation was significantly inhibited in co-culture containing 39% of AT-MSC (*p < 0.05). B. 8MGBA cells 1.5 × 10⁶ or 1 × 10⁷ were injected s.c. either alone, admixed to AT-MSC at a ratio 1:1 or 1:10 or 1 × 10⁶ AT-MSC i.v. AT-MSC decreased the tumor incidence by day 55 from 60% in 8MGBA alone group to 33% in 8MGBA/AT-MSC 10:1 group and 17% in 8MGBA/AT-MSC 1:1 group. Systemic AT-MSC administration significantly decreased tumor incidence to 37.5% (*p = 0.0304). C. 8MGBA expression profile demonstrated expression of EGFR, VEGF-A,-B, VEGFR-1,-2 PDGF-bb, cKit, SDF-1α (high), CXCR4, CCL5, HGF, cMet (low). Quantitative differences were detected in higher level of SDF-1α expression and lower level of cMet receptor expression in comparison to A375 melanoma. D. 8MGBA, AT-MSC, or 8MGBA/AT-MSC (ratio 2:1) were directly co-cultured in complete media for 3 days. Level of cytokines in cell-free supernatants was determined by Bio-Plex cytokine arrays and normalized to the levels observed in the media of 8MGBA cells cultured alone. Mostly, the effects were additive, increased level of IL-1β and IFN-γ was observed in directly cocultured cells. Data were expressed as average fold induction. ND, not detected.