Kran SuknunthaYoon Jung ChoiHo Sun JungAditi MajumderSujal ShahIgor SlukvinErik A. RanheimUniversity of Wisconsin-MadisonFaculty of Medicine, Ramathibodi Hospital, Mahidol UniversityWisconsin National Primate Research Center2021-02-032021-02-032020-12-09Frontiers in Oncology. Vol.10, (2020)2234943X2-s2.0-85098157954https://repository.li.mahidol.ac.th/handle/123456789/60871© Copyright © 2020 Suknuntha, Choi, Jung, Majumder, Shah, Slukvin and Ranheim. Numerous recurrent genetic mutations are known to occur in acute myeloid leukemia (AML). Among these common mutations, Fms-like tyrosine kinase 3 remains as one of the most frequently mutated genes in AML. We observed apparent marrow expansion of megakaryocytes in three out of six patients with Flt3-mutated AML following treatment with a recently FDA-approved Flt3 inhibitor, gilteritinib which possesses activity against internal tandem duplication and tyrosine kinase domain Flt3 mutations and also inhibits tyrosine kinase AXL. To assess whether biopsy findings can be attributed to promotion of megakaryocytic (Mk) differentiation with gilteritinib, we devised a cellular assay by overexpressing double mutated Flt3-ITDY591F/Y919F in chronic myeloid leukemia cell line K562 to study Mk differentiation in the presence of Flt3 and AXL inhibitors with non-mutually exclusive mechanisms. These experiments demonstrated the lack of direct effect Flt3 inhibitors gilteritinib and quizartinib on megakaryocytic differentiation at either transcriptional or phenotypic levels, and highlighted antileukemic effects of AXL receptor tyrosine kinase inhibitor and its potential role in megakaryocytic development.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyArticleSCOPUS10.3389/fonc.2020.585151