Constitutively activating internal tandem duplication (ITD) mutations of the receptor tyrosine kinase FLT3 (Fms-like tyrosine kinase 3) play an important role in leukemogenesis, and their presence is associated with poor prognosis in acute myeloid leukemia (AML). To better understand FLT3 signaling in leukemogenesis, we have examined the changes in gene expression induced by FLT3/ITD or constit...

We investigated the patients with solid cancers harboring Fms-like tyrosine kinase 3 (FLT3) amplification using targeted sequencing of tumor tissue specimen and FISH assay. Simultaneously, FLT3-amplified patient-derived cells (PDCs) were generated to evaluate the sensitivity to FLT3 inhibition. A patient with metastatic colon cancer who was previously treated with more than 3rd line cytotoxic c...

Hematopoiesis is highly regulated through cytokine-induced stimulation of multiple signal transduction pathways in order to mediate appropriate differentiation and proliferation of specific progenitor populations. Ligand-induced stimulation of the FMS-like tyrosine kinase 3 (FLT3) leads to activation of multiple downstream effector pathways resulting in differentiation and proliferation of spec...

Several studies have shown that internal tandem duplication (ITD) of FMS-like tyrosine kinase 3 (FLT3) can result in the failure of leukemia treatment and contribute to a poor prognosis. However, the role of the overexpression of FLT3 in leukemia remains to be fully elucidated. By mining public database, the present study first identified that the expression of FLT3 in leukemia was markedly hig...

Activation of the Hedgehog pathway has been implicated in the pathogenesis of several tumor types including myeloid leukemia. Previously we demonstrated that overexpression of Hedgehog downstream mediators GLI1/2 confers an adverse prognosis to patients with acute myeloid leukemia (AML) and is correlated with a FLT3 mutated status. To analyze a possible non-canonical activation of the Hedgehog ...

The type III receptor tyrosine kinase fms-like tyrosine kinase 3 (FLT3) is expressed on both normal hematopoietic stem cells and acute myeloid leukemia (AML) cells and regulates their proliferation. Internal tandem duplication (ITD) mutation of FLT3 is present in a third of AML cases, results in constitutive activation and aberrant signaling of FLT3, and is associated with adverse treatment out...

Acute promyelocytic leukemia (APL) is characterized by the specific PML-RARα fusion gene resulting from translocation t(15;17) (q22;q12). Internal tandem duplication (ITD) of the FLT3 gene has been observed in approximately 35% of APLs, and large-scale studies have identified the presence of ITD as an adverse prognostic factor for acute myeloblastic leukemia (AML) patients. Aberrant expressions...

Internal tandem duplication mutations of the FLT3 gene (FLT3/ITD mutations) are the most frequent molecular abnormality in acute myeloid leukemia (AML) and are associated with a poor overall survival. While the normal FLT3 receptor is expressed in early hematopoietic progenitor cells, it has not been determined whether FLT3 mutations are present in the leukemic stem cells. In this study, we sor...

Fms-like tyrosine kinase-3 (FLT3) is a receptor tyrosine kinase that normally functions in hematopoietic cell survival, proliferation and differentiation. Constitutively activating mutations of FLT3 map predominately to the juxtamembrane domain (internal tandem duplications; ITD) or the activation loop (AL) of the kinase domain and are detected in about 1/3 of de novo acute myeloid leukemia (AM...

Oncogenic forms of the kinase FLT3 are important therapeutic targets in acute myeloid leukemia (AML); however, clinical responses to small-molecule kinase inhibitors are short-lived as a result of the rapid emergence of resistance due to point mutations or compensatory increases in FLT3 expression. We sought to develop a complementary pharmacological approach whereby proteasome-mediated FLT3 de...