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Letters to the Editor
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Figure 1. Characterization of CHMFL-FLT3-362 as a highly selective FLT3-ITD mutants kinase inhibitor. (A) Chemical structure of CHMFL-FLT3-362. (B) Invitrogen
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FLT3-362 against FLT3, FLT3/ITD, KIT, PDGFRα, PDGFRβ, CSF1R, FLT1 and VEGFR2. In vitro kinase activity was measured by Invitrogen Z’-LYTE assay (IC
s of CHMFL-FLT3-362 against FLT3 wild-type (wt)/ITD kinases. Error bars, mean±standard error of mean (SEM), n=3. (C) Kinetic study of CHMFL-FLT3-362 against FLT3-wt/ITD kinase with varied concentrations (10 nM, 30 nM and 100 nM, respectively) of ATP. (D) Determination of the growth inhibition effects of CHMFL-FLT3-362 against a panel of 22 BaF3 engineered cell lines (including different ITD sequences and mutants), three FLT3-ITD+ human leukemia cell lines and three FLT3-wt human leukemia cell lines. Cells were treated with CHMFL-FLT3-362 (maximum con- centration 10 mM) for 72 hours (h), and cell viability was measured using the Cell Titer-Glo assay. Error bars, mean±SEM, n=3. (E) (Left) Kinome-wide selectivity profiling of CHMFL-FLT3-362 with DiscoverX’s KINOMEscanTM technology (http://www.kinomescan.com). Red circles indicate kinases bound, and circle size indi- cates relative binding affinity compared to DMSO (Ctrl%). The complete dataset is shown in Online Supplementary Table S2. (Right) Inhibition effects of CHMFL-
(Madison, WI, USA) Z’LYTE biochemical assay determination of the IC
mean±SEM, n=3) and engineered BaF3 cell lines (GI
: mM, mean±SEM, n=3).
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: mM,
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haematologica | 2021; 106(2)