Figure 1

Ex vivo DRP Identification and in vivo validation of a t(1;9)(q24;q34) RCSD1-ABL1 bearing patient sensitivity to ponatinib. (a) Ficoll-purified blood cells obtained from the patient at relapse (April 2014) were exposed for 48 h to varying concentrations of the indicated TKIs, and cell viability was assessed using CellTiter-Glo luminescent assay (Promega, Charbonnières les Bains, France). The data are presented as percent viability after normalization to negative control (dimethyl sulfoxide only). (b) Effective half-maximal concentration values (EC50) deduced from the dose-response curves obtained in duplicate from two distinct drug testing plates (plate #1 and plate #2) are shown. (c) As in a, except that Ficoll-purified blood cells obtained from the patient at diagnosis (September 2012) and at relapse (April 2014) were exposed for 48 h to varying concentrations of dasatinib and ponatinib. (d) Ficoll-purified blood cells obtained from the patient at diagnosis (September 2012) and at relapse (April 2014) were inoculated in the tail vein of NSG mice and the presence of human B-ALL blast cells in peripheral blood obtained by retro-orbital bleeding was determined by flow cytometry at different time points. Results are presented as the number of human CD45 positive cells per μl of mice blood (mean±s.e.m., 4 animals per group). (e) Secondary transplantation was conducted by injecting bone marrow cells of primary transplanted mice from d in new NSG recepients. At day 50 after secondary transplantation, human blasts present in mice blood were determined to homogeneously distribute recepient mice into three groups receiving vehicle, dasatinib (25 mg/kg, po) or ponatinib (30 mg/kg). Results are presented as the number of human CD45 positive cells per μl of mice blood as determined by Flow cytometry at day 14 and day 28 after initiation of treatment (mean±s.e.m., 8 animals per group). The data were analyzed with a one-way analysis of variance test (GraphPad Prism, GraphPad, La Jolla, CA, USA) and each group was further compared with the vehicle control group for statistical significance using Dunnett multiple comparison test. ***P<0.0001.