Induction of caspase-3/7 following treatment with RAMBO, cilengitide, and RAMBO and cilengitide combined in vitro. Assay of caspase-3/7 activity. U87ΔEGFR glioma cells were treated with cilengitide, RAMBO, and RAMBO and cilengitide combined (same as above). At 16 h after infection with RAMBO and 13 h after adding cilengitide or PBS, caspase activity was evaluated in the cells using the CellEvent™ Caspase-3/7 Green Detection Reagent. Caspase-3/7 activity was increased in the treated cells; especially, a significant increase of caspase-3/7 activity was observed in the cells treated with cilengitide and RAMBO and cilengitide combined. There was a significant increase in the activity of caspase-3/7 in the cells treated with the combination therapy compared to RAMBO monotherapy, cilengitide monotherapy, and untreated cells (P = 0.0008, P = 0.0117, and P = 0.0008, respectively).