Phosphoproteomic characterization of primary AML samples and relevance for response towards FLT3-inhibitors

ABSTRACT: Kinase hyperactivity is a common driver of acute myeloid leukemia (AML) and serves as a therapeutic target. The most frequent genetic aberration leading to hyperactive kinase signaling and poor prognosis is internal tandem duplication (ITD) of the FMS-tyrosine-like Kinase 3-gene (FLT3). FLT3-ITD induces ligand independent activation of FLT3 and downstream pathways leading to proliferation, decreased apoptosis and partial differentiation block. Combined with chemotherapy, FLT3-Tyrosine Kinase Inhibitor (FLT3-TKI) midostaurin improves overall survival (OS) of newly diagnosed FLT3-mutated AML patients, whereas single agent gilteritinib proved superior to chemotherapy in relapsed/refractory FLT3-mutated AML patients . As the primary targets of currently approved FLT3-TKIs are tyrosine (Y) kinases, we hypothesized that direct evaluation of tyrosine phosphorylation status could reveal pY phosphorylation profiles associated with FLT3-TKI response. Therefore, we used label-free pTyr-based phosphoproteomics in 35 primary AML samples (18 FLT3-WT, 17 FLT3-ITD), to identify differentially phosphorylated proteins underlying response to the FLT3-TKIs gilteritinib and midostaurin. We identified a total of 3024 unique phosphosites (median 1299 per sample, range 286 – 1612, pS:pT:pY 11.9%:9.5%:78.6%). Due to low number of identified phosphosites, we excluded two samples from further analyses. On the remaining 33 samples, we additionally performed IMAC global phosphoproteomics and on 17 samples protein expression analysis.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Blood Cell, Blood

DISEASE(S): Acute Myeloid Leukemia

SUBMITTER: Sander Piersma  

LAB HEAD: Connie Ramona Jimenez

PROVIDER: PXD024235 | Pride | 2021-09-10

REPOSITORIES: Pride