2. Cell viability assay

Cell viability was measured using the CellTiter-Glo Luminescent Cell Viability Assay (Promega, Madison, WI) in accordance with the instruction manual. Briefly, 3×10³ cells were plated in triplicate wells in 96 microtiter plates in a volume of 90 μL. On the following day, the cells were incubated with the desired concentrations of AUY922 and/or TAE226 and/or cilengitide to a final volume of 100 μL. After 72 hours, 100 μL of CellTiter-Glo reagent was added and the cells were then incubated for 10 minutes at room temperature. The luminescence levels were measured using a Wallac 1420 (PerkinElmer, Boston, MA).