Saracatinib

Cell viability assays were performed using WST-8 (Roche Diagnostics, Mannheim, Germany) according to the manufacturer’s instructions^{18 (link)}. Cells were cultured in 24-well plates. Twenty-four hours after treatment with the indicated concentrations of A419259 (Tocris Bioscience), SKI-1 (Abcam, Cambridge, UK), PP2 (Cayman Chemical, MI, USA), saracatinib (Santa Cruz) or bosutinib (abcam), cells were incubated with the WST-8 substrate for 2–3 h, after which the absorbance of the wells was measured at 450 nm using a plate reader (2300 EnSpire^TM, PerkinElmer, Yokohama, Japan). The number of live cells was determined using a Countess cell counter (Invitrogen) after cultures were stained with trypan blue. Toxicity assays were performed using the Cytotoxicity Detection Kit PLUS (Roche Diagnostics, Indianapolis, IN). Twenty-four hours after treating the cells, 100 μL of the medium were removed from the plate and used in the assay. The medium was incubated with the substrate for 15 min and spectrophotometrically assayed at 490 nm using a plate reader. To activate the Src vector, we used MLR1023 (#4582) (Tocris Bioscience, Bristol, UK).