Fig. 1

Short exposure to high concentrations of sunitinib provokes tumor cell death, while serially treatment with this scheduling does not induce resistance. a 786-O RCC cells were exposed to 5, 10 and 20 μM of sunitinib for the depicted time intervals, ranging from 1 – 144 h exposure. Proliferation was studied at 144 h with MTT. b The indicated cancer cell lines were exposed to 20 μM of sunitinib for the various time intervals (range 1- 144 h). Proliferation was studied at t = 144 h with MTT. Exposure to 20 μM of sunitinib for 9 h resulted in tumor cell death, independent of cell line. c 786-O RCC cells were exposed to indicated sunitinib concentrations (range 0 – 20uM) for 6 h and intracellular accumulation of sunitinib was calculated. d Sensitivity to sunitinib, determined with proliferation assay, of cells sequentially treated with 20 μM for 9 h (n = 4 times) was compared to the sensitivity of untreated cells. e Photos depicting the regrowth of 786-O RCC cells after 9 h exposure to 20 μM of sunitinib. Control, untreated, D, days after exposure. Error bars, SEM