Fig. 4From: Mesenchymal stem cells enhance the oncolytic effect of Newcastle disease virus in glioma cells and glioma stem cells via the secretion of TRAILCombined treatment of GSCs with conditioned medium derived from NDV-infected UC-MSCs and radiation exerts a synergistic cytotoxic effect on GSCs. The HF2355 GSCs were infected with NDV and irradiated (3 Gy) (a). The self-renewal of the cells was determined after 10 days of treatment. HF2355 GSCs were irradiated in the presence or absence of conditioned medium derived from NDV-infected UC-MSCS (b, c). Cell death was determined after 3 days using LDH (b) or caspase 3/7 (c) assays. The role of TRAIL in the increased sensitization to radiation was examined in the HF2359 GSCs. The addition of a neutralizing anti-TRAIL antibody (5 μg/ml) prior to NDV infection and γ-irradiation abrogated the increased cytotoxic effect of the infected UC-MSCs conditioned medium and that of the combined effects of γ-radiation and the conditioned medium. Cell death was measured using LDH assay and data are presented as relative cell death (d). The results are presented as the means ± SE and represent three different experiments. * p < 0.001; ** p < 0.01. (*Control vs. infected cells; radiation + CM of NDV-infected UC-MSCs vs. radiation or NDV alone; control vs. anti-TRAIL antibody; **GSCs treated with UC-MSC CM and NDV infected GSCs vs. untreated cells). MSC mesenchymal stromal cells cell, NDV Newcastle disease virus, TRAIL TNF-related apoptosis-inducing ligand, UC umbilical cordBack to article page