Journal Article

Expression of myeloid Src-family kinases is associated with poor prognosis in AML and influences Flt3-ITD kinase inhibitor acquired resistance

Snyder, Daniel, Shen, Kexin, Cooper, Vaughn S., Patel, Ravi K., Smithgall, Thomas E., Weir, Mark C.

2019

Overview

Unregulated protein-tyrosine kinase signaling is a common feature of AML, often involving mutations in Flt3 and overexpression of myeloid Src-family kinases (Hck, Fgr, Lyn). Here we show that high-level expression of these Src kinases predicts poor survival in a large cohort of AML patients. To test the therapeutic benefit of Flt3 and Src-family kinase inhibition, we used the pyrrolopyrimidine kinase inhibitor A-419259. This compound potently inhibits Hck, Fgr, and Lyn as well as Flt3 bearing an activating internal tandem duplication (ITD). Flt3-ITD expression sensitized human TF-1 myeloid cells to growth arrest by A-419259, supporting direct action on the Flt3-ITD kinase domain. Cells transformed with the Flt3-ITD mutants D835Y and F691L were resistant to A-419259, while co-expression of Hck or Fgr restored inhibitor sensitivity to Flt3-ITD D835Y. Conversely, Hck and Fgr mutants with engineered A-419259 resistance mutations decreased sensitivity of TF-1/Flt3-ITD cells. To investigate de novo resistance mechanisms, A-419259-resistant Flt3-ITD+ AML cell populations were derived via long-term dose escalation. Whole exome sequencing identified a distinct Flt3-ITD kinase domain mutation (N676S/T) among all A-419259 target kinases in each of six independent resistant cell populations. These studies show that Hck and Fgr expression influences inhibitor sensitivity and the pathway to acquired resistance in Flt3-ITD+ AML.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Amino Acid Substitution / B cells / Bioinformatics / Biology and Life Sciences / Biotechnology industries / Bone marrow / Cancer therapies / Cell Line, Tumor / Chemotherapy / Drug Resistance, Neoplasm - drug effects / Drug Resistance, Neoplasm - genetics / EDTA / Enzyme inhibitors / fms-Like Tyrosine Kinase 3 - antagonists & inhibitors / fms-Like Tyrosine Kinase 3 - genetics / fms-Like Tyrosine Kinase 3 - metabolism / Gene Expression Regulation, Developmental - drug effects / Gene Expression Regulation, Leukemic - drug effects / Genetics / Genomes / Hck protein / Health aspects / Humans / Inhibitors / Kinases / Leukemia / Leukemia, Myeloid, Acute - diagnosis / Leukemia, Myeloid, Acute - drug therapy / Leukemia, Myeloid, Acute - enzymology / Leukemia, Myeloid, Acute - genetics / Ligands / Medical prognosis / Medicine / Medicine and Health Sciences / Midostaurin / Mutants / Mutation / Mutation, Missense / Myeloid cells / Patients / Phenols (Class of compounds) / Physical Sciences / Population studies / Populations / Prognosis / Protein Kinase Inhibitors - pharmacology / Protein-tyrosine kinase / Proto-Oncogene Proteins - biosynthesis / Proto-Oncogene Proteins - genetics / Proto-Oncogene Proteins c-hck - biosynthesis / Proto-Oncogene Proteins c-hck - genetics / Pyrimidines - pharmacology / Pyrroles - pharmacology / Research and Analysis Methods / Sensitivity / Src protein / src-Family Kinases - biosynthesis / src-Family Kinases - genetics / Stem cells / Tyrosine / Whole Exome Sequencing