title: The STAT5 Inhibitor Pimozide Displays Efficacy in Models of Acute Myelogenous Leukemia Driven by FLT3 Mutations.
abstract: Activation of the transcription factor STAT5 is essential for the pathogenesis of acute myelogenous leukemia (AML) containing the FLT3 internal tandem duplication (ITD) mutation. FLT3 ITD is a constitutively active tyrosine kinase that drives the activation of STAT5, leading to the growth and survival of AML cells. Although there has been some success in identifying tyrosine kinase inhibitors that block the function of FLT3 ITD, there remains a continued need for effective treatment of this disease. We have identified the psychotropic drug pimozide as an effective inhibitor of STAT5 function. Pimozide inhibits the tyrosine phosphorylation of STAT5, leading to the death of AML cells through the induction of apoptosis. Pimozide shows a combinatorial effect with the tyrosine kinase inhibitors midostaurin (PKC412) and sunitinib in the inhibition of STAT5 tyrosine phosphorylation and the induction of apoptosis. Significantly, pimozide reduces the tumor burden in a mouse model of FLT3-driven AML. Therefore, identifying STAT5 inhibitors may provide a new avenue for the treatment of AML, and these may be effective alone or in combination with tyrosine kinase inhibitors.
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute and Department of Medicine, Brigham and Women's Hospital, Boston, MA,USA.
authors.forename: Erik A
authors.initials: EA
authors.lastname: Nelson
authors.forename: Sarah R
authors.initials: SR
authors.lastname: Walker
authors.forename: Michael
authors.initials: M
authors.lastname: Xiang
authors.forename: Ellen
authors.initials: E
authors.lastname: Weisberg
authors.forename: Michal
authors.initials: M
authors.lastname: Bar-Natan
authors.forename: Rosemary
authors.initials: R
authors.lastname: Barrett
authors.forename: Suiyang
authors.initials: S
authors.lastname: Liu
authors.forename: Surender
authors.initials: S
authors.lastname: Kharbanda
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Christie
authors.forename: Maria
authors.initials: M
authors.lastname: Nicolais
authors.forename: James D
authors.initials: JD
authors.lastname: Griffin
authors.forename: Richard M
authors.initials: RM
authors.lastname: Stone
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Kung
authors.forename: David A
authors.initials: DA
authors.lastname: Frank