Gene expression patterns in response to IL-3 in human AML patient mononuclear cells

Aberrant activation of -catenin is a common event in Acute Myeloid Leukemia (AML), and is recognized as an independent predictor of poor prognosis. Although increased -catenin signaling in AML has been associated with AML1-ETO and PML-RAR translocation products, and activating mutations in the FLT3 receptor, it remains unclear which mechanisms activate -catenin in AML more broadly. Here, we describe a novel link between interleukin-3 (IL-3) signaling and the regulation of -catenin in myeloid transformation and AML. Using a murine model of HoxB8 and IL-3 cooperation we show that IL-3 modulates -catenin protein levels, and Cre-induced deletion of -catenin abolishes IL-3 dependent growth and colony formation. In the erythroleukemic cell line TF-1.8, we observed increased -catenin protein levels and nuclear localization in response to IL-3, which correlated with transcriptional induction of -catenin target genes. Furthermore, IL-3 promoted -catenin accumulation in a subset of AML patient samples, and microarray gene expression analysis of these cells revealed induction of WNT/-catenin and TCF4 transcriptional gene signatures in an IL-3 dependent manner. This study is the first to link -catenin activation to IL-3 and suggests that targeting IL-3 signaling may be an effective approach for the inhibition of -catenin activity in some patients with AML.

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Sadras T, Perugini M, Kok CH, Iarossi DG, Heatley SL, Brumatti G, Samuel MS, To LB, Lewis ID, Lopez AF, Ekert PG, Ramshaw HS, D'Andrea RJ