3-(1-(3-(biphenyl-4-ylamino)-3-oxopropyl)-1h-1-2-3-triazol-4-yl)-6-hydroxy-1-methyl-2-phenyl-1h-indole-5-carboxylic-acid and Leukemia--Myeloid--Acute

Internal tandem duplications (ITDs) in the fms-like tyrosine kinase receptor (FLT3-ITDs) confer a poor prognosis in acute myeloid leukemia (AML). We hypothesized that increased recruitment of the protein tyrosine phosphatase, Shp2, to FLT3-ITDs contributes to FLT3 ligand (FL)-independent hyperproliferation and STAT5 activation. Co-immunoprecipitation demonstrated constitutive association of Shp2 with the FLT3-ITD, N51-FLT3, as well as with STAT5. Knockdown of Shp2 in Baf3/N51-FLT3 cells significantly reduced proliferation while having little effect on WT-FLT3-expressing cells. Consistently, mutation of N51-FLT3 tyrosine 599 to phenylalanine or genetic disruption of Shp2 in N51-FLT3-expressing bone marrow low-density mononuclear cells reduced proliferation and STAT5 activation. In transplants, genetic disruption of Shp2 in vivo yielded increased latency to and reduced severity of FLT3-ITD-induced malignancy. Mechanistically, Shp2 co-localizes with nuclear phospho-STAT5, is present at functional interferon-γ activation sites (GAS) within the BCL2L1 promoter, and positively activates the human BCL2L1 promoter, suggesting that Shp2 works with STAT5 to promote pro-leukemogenic gene expression. Further, using a small molecule Shp2 inhibitor, the proliferation of N51-FLT3-expressing bone marrow progenitors and primary AML samples was reduced in a dose-dependent manner. These findings demonstrate that Shp2 positively contributes to FLT3-ITD-induced leukemia and suggest that Shp2 inhibition may provide a novel therapeutic approach to AML.

Topics: Animals; Base Sequence; bcl-X Protein; Blotting, Western; Bone Marrow Transplantation; Cell Proliferation; Chromatin Immunoprecipitation; Fluorescent Antibody Technique; fms-Like Tyrosine Kinase 3; Hematopoietic Stem Cells; Humans; Immunoprecipitation; Indoles; Leukemia, Myeloid, Acute; Mice; Mice, Inbred C57BL; Mice, Knockout; Molecular Sequence Data; Mutation; Phosphorylation; Precursor Cells, B-Lymphoid; Promoter Regions, Genetic; Protein Tyrosine Phosphatase, Non-Receptor Type 11; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; STAT5 Transcription Factor; Survival Rate; Tandem Repeat Sequences; Triazoles