Fig. 4

let-7b targets the 3’UTR and downregulates AML1-ETO in t(8;21) AML cells. a, b Representative western blots and protein quantification of Kasumi-1 and SKNO-1 whole cell lysates probed for endogenous AML1-ETO or α-Tubulin 48 h post-transfection with let-7b-5p or control miRNA mimics (a), or in cells stably expressing an anti-let-7 miRNA family sponge or control cells (b). c let-7b-5p or control miRNA mimics were co-transfected into Kasumi-1 cells with the AML1-ETO 3′UTR fragment #8 luciferase reporter and luciferase assays were performed 72 h post-transfection. Data is shown as relative luciferase activity normalized to control mimics. d Schematic of WT (AE-WT) and let-7 targeting mutant (AE-MUT) AML1-ETO 3′UTR fragment #8 luciferase reporters. e Luciferase assay results of AE-WT and AE-MUT reporters in Kasumi-1 or SKNO-1 cells 72 h post-transfection. f Kasumi-1 and SKNO-1 cell lines stably expressing either an anti-let-7 miRNA family sponge or control cells were transfected with the AE-WT or AE-MUT 3′UTR reporters and luciferase assays were performed 72 h later. Data is shown as relative luciferase activity normalized to control cell lines. All data in this figure is presented as the average and SD of the indicated number of individual experiments, unpaired t-tests with corrections for multiple tests using the Holm-Sidak method