Targeting miR‐126 disrupts maintenance of myelodysplastic syndrome stem and progenitor cells

Background Myelodysplastic syndrome (MDS) arises from a rare population of aberrant hematopoietic stem and progenitor cells (HSPCs). These cells are relatively quiescent and therefore treatment resistant. Understanding mechanisms underlying their maintenance is critical for effective MDS treatment. Methods We evaluated microRNA‐126 (miR‐126) levels in MDS patients’ sample and in a NUP98‐HOXD13 (NHD13) murine MDS model along with their normal controls and defined its role in MDS HSPCs’ maintenance by inhibiting miR‐126 expression in vitro and in vivo. Identification of miR‐126 effectors was conducted using biotinylated miR‐126 pulldown coupled with transcriptome analysis. We also tested the therapeutic activity of our anti‐miR‐126 oligodeoxynucleotide (miRisten) in human MDS xenografts and murine MDS models. Results miR‐126 levels were higher in bone marrow mononuclear cells from MDS patients and NHD13 mice relative to their respective normal controls (P