Fig. 1

Primary hAMSCs engineered to express TRAIL under the control of TGF-β. a Schematic of SBE4TRAIL-duet lentiviral and hAMSC-SEB4-TRAIL production (TGF-β trigger TRAIL delivery system). b Flow cytometric analysis was performed to confirm that primary hAMSC-SBE4-TRAIL expressed high level of CD73, CD90, and CD105. Meanwhile, CD31, CD34, and CD54 positive cells were absent in these stem cells. c Western blots were performed to test the TRAIL expression of hAMSC-SBE4-TRAIL presence or absence of extrinsic TGF-β1 and/or TGF-β2 at 10 ng/ml with or without TGF-β receptor inhibitor (LY2109761, Eli Lilly). d Immunohistochemistry staining was used to determine the TGF-β level in the normal cortex and glioblastoma tissues. Scale bar, 100 μm. e Schema showing the collection of these primary patient-derived GBM cells conditioned media (GBM-CM). f The concentration of TRAIL in hAMSC-vector and hAMSC-SBE4-TRAIL that were pretreated in the astrocyte-CM and three GBM-CM for 24 h was measured using an ELISA kit