The colony-Stimulating factor 3 receptor T640N mutation is oncogenic, sensitive toJAKInhibition, and mimics T618i

Julia E. Maxson, Samuel B. Luty, Jason D. MacManiman, Jason C. Paik, Jason Gotlib, Peter Greenberg, Swaleh Bahamadi, Samantha L. Savage, Melissa L. Abel, Christopher A. Eide, Marc M. Loriaux, Emily A. Stevens, Jeffrey W. Tyner

Research output: Contribution to journalArticlepeer-review

37 Scopus citations


Purpose: Colony-stimulating factor 3 receptor (CSF3R) mutations have been identified in the majority of chronic neutrophilic leukemia (CNL) and a smaller percentage of atypical chronic myeloid leukemia (aCML) cases. Although CSF3R point mutations (e.g., T618I) are emerging as key players in CNL/aCML, the significance of rarer CSF3R mutations is unknown. In this study, we assess the importance of the CSF3R T640N mutation as a marker of CNL/aCML and potential therapeutic target. Experimental Design: Sanger sequencing of leukemia samples was performed to identifyCSF3Rmutations inCNLand aCML. The oncogenicity of the CSF3R T640N mutation relative to the T618I mutation was assessed by cytokine independent growth assays and by mouse bone marrow transplant. Receptor dimerization and Oglycosylation of themutants was assessed by Western blot, and JAK inhibitor sensitivity was assessed by colony assay. Results: Here, we identify a CSF3R T640N mutation in two patients with CNL/aCML, one of whom was originally diagnosed with MDS and acquired the T640N mutation upon evolution of disease to aCML. The T640N mutation is oncogenic in cellular transformation assays and an in vivo mouse bone marrow transplantation model. It exhibits many similar phenotypic features to T618I, including ligand independence and altered patterns of O-glycosylation-despite the transmembrane location of T640 preventing access by GalNAc transferase enzymes. Cells transformed by the T640N mutation are sensitive to JAK kinase inhibition to a similar degree as cells transformed by CSF3R T618I. Conclusions: Because of its similarities to CSF3R T618I, the T640N mutation likely has diagnostic and therapeutic relevance in CNL/aCML.

Original languageEnglish (US)
Pages (from-to)757-764
Number of pages8
JournalClinical Cancer Research
Issue number3
StatePublished - Feb 1 2016

ASJC Scopus subject areas

  • Oncology
  • Cancer Research


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