Time course of dasatinib and imatinib uptake. (A) The uptake of ¹⁴C radiolabeled dasatinib into parental (◇), mock-transfected (■), and hOCT1-transfected KCL22 cells with low (▴) and high (×) expression of hOCT1. Data represent mean plus or minus SEM from 3 experiments. (B) The uptake of ¹⁴C radiolabeled imatinib for comparison. Data represent mean plus or minus SEM from 5 experiments. There is a greater uptake in high hOCT1-expressing than into mock-transfected cells, with P = .02 for dasatinib and P = .01 for imatinib between 0 to 120 minutes and P = .013 and P = .015, respectively, at 30 minutes. AUC for dasatinib versus imatinib uptake on KCL22 cells is 67.6 versus 33.3 (P = .001) and on high hOCT1-expressing cells is 92.1 versus 47.7 (P = .003).