SRC is a signaling mediator in FLT3-ITD-but not in FLT3-TKD-positive AML
Författare
Summary, in English
Mutations of Fms-like tyrosine kinase 3 (FLT3) are among the most frequently detected molecular abnormalities in AML patients. Internal tandem duplications (ITDs) are found in approximately 25% and point mutations within the second tyrosine kinase domain (TKD) in approximately 7% of AML patients. Patients carrying the FLT3-ITD but not the FLT3-TKD mutation have a significantly worse prognosis. Therefore, both FLT3 mutations seem to exert different biologic functions. FLT3-ITD but not FLT3-TKD has been shown to induce robust activation of the STAT5 signaling pathway. In the present study, we investigated the mechanisms leading to differential STAT5 activation and show that FLT3-ITD but not FLT3-TKD uses SRC to activate STAT5. Coimmunoprecipitation and pull-down experiments revealed an exclusive interaction between SRC but not other Src family kinases and FLT3-ITD, which is mediated by the SRC SH2 domain. We identified tyrosines 589 and 591 of FLT3-ITD to be essential for SRC binding and subsequent STAT5 activation. Using sitespecific Abs, we found that both residues were significantly more strongly phosphorylated in FLT3-ITD compared with FLT3-TKD. SRC inhibition and knockdown blocked STAT5 activation and proliferation induced by FLT3-ITD but not by FLT3-TKD. We conclude that SRC might be a therapeutic target in FLT3-ITD+ AML. (Blood. 2012;119(17):4026-4033)
Avdelning/ar
- Institutionen för translationell medicin
- BioCARE: Biomarkers in Cancer Medicine improving Health Care, Education and Innovation
Publiceringsår
2012
Språk
Engelska
Sidor
4026-4033
Publikation/Tidskrift/Serie
Blood
Volym
119
Issue
17
Dokumenttyp
Artikel i tidskrift
Förlag
American Society of Hematology
Ämne
- Hematology
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1528-0020