Figure 3.

Bispecific immunotoxin induces cell death of GBM cells in vitro.

Notes: *P<0.05; error bars represent triplicate experiments. (A) The GBM cell line U251 was incubated with varying supernatants from VEGF₁₆₅-ephrin A1-PE38KDEL-transduced hMSCs, and cell activity was determined by CCK-8 assay. (B) In vitro activity of immunotoxins against GBM cell lines. U251 and U87 were cultured with 50 µL supernatants from transduced (VEGF₁₆₅-ephrin A1-PE38KDEL, VEGF₁₆₅-PE38KDEL, and ephrin A1-PE38KDEL) and untransduced (UT) hMSCs, and cell proliferation was assessed at 48 hours. (C) Blocking assay with anti-ephrin A1 and anti-VEGF antibodies. U251 cells were exposed to VEGF₁₆₅-ephrin A1-PE38KDEL supernatant fractions in the presence or absence of anti-ephrin A1 and anti-VEGF, and cell proliferation was determined 72 hours later.

Abbreviations: GBM, glioblastoma multiforme; PE, Pseudomonas exotoxin; hMSCs, human mesenchymal stem cells; CCK, Cell Counting Kit.