Fig. 1

Increased AXL protein level after 24 h of low μM treatment with selective AXL TKI. BMS777607 (BMS) treatment led to increased AXL protein levels in (a) Hs578T, (b) H292 and (c) MDA-MB231 cells. Western blots of AXL after treatment with a three-fold serial dilution of BMS from 20 μM to 1.01 nM are shown. ACTIN or GAPDH served as loading controls. A representative sample of multiple biological replicates is displayed. (d) Treatment with low μM concentrations of BMS increased the viability of 3D cell spheroids. Cells were cultivated in a 3D matrix in the presence of BMS (0.001 μM to 12.5 μM). ATP measurements were performed after 72 h. All results were normalized to DMSO control values as indicated by a doted horizontal line. Low BMS concentrations between 0.097 μM and 0.78 μM increased significantly the ATP content of Caliper, MDA-MB231, H292 and H1792 cells in a rage of 110 to 125%, in contrast to Hs578T cells. BMS treatment had no impact on AXL mRNA transcription. 0.5 μM BMS treatment showed no change of AXL mRNA levels by RT-qPCR analysis within 4 h in (e) Hs578T, (f) H292 and (g) H1792 cells. Housekeeping genes GAPDH and ALAS served as normalization controls utilizing the ΔΔCT method. Two different primer sets were used namely, P3 and PB. Mean values and SEM of three independent experiments are shown