title: AML1/MTG8 oncogene suppression by small interfering RNAs supports myeloid differentiation of t(8;21)-positive leukemic cells.
abstract: The translocation t(8;21) yields the leukemic fusion gene AML1/MTG8 and is associated with 10%-15% of all de novo cases of acute myeloid leukemia. We demonstrate the efficient and specific suppression of AML1/MTG8 by small interfering RNAs (siRNAs) in the human leukemic cell lines Kasumi-1 and SKNO-1. siRNAs targeted against the fusion site of the AML1/MTG8 mRNA reduce the levels of AML1/MTG8 without affecting the amount of wild-type AML1. These data argue against a transitive RNA interference mechanism potentially induced by siRNAs in such leukemic cells. Depletion of AML1/MTG8 correlates with an increased susceptibility of both Kasumi-1 and SKNO-1 cells to tumor growth factor beta(1) (TGF beta(1))/vitamin D(3)-induced differentiation, leading to increased expression of CD11b, macrophage colony-stimulating factor (M-CSF) receptor, and C/EBP alpha (CAAT/enhancer binding protein). Moreover, siRNA-mediated AML1/MTG8 suppression results in changes in cell shape and, in combination with TGF beta(1)/vitamin D(3), severely reduces clonogenicity of Kasumi-1 cells. These results suggest an important role for AML1/MTG8 in preventing differentiation, thereby propagating leukemic blast cells. Therefore, siRNAs are promising tools for a functional analysis of AML1/MTG8 and may be used in a molecularly defined therapeutic approach for t(8;21)-positive leukemia.
authors.affiliation: Department of Molecular Biology, Institute for Cell Biology, University of Tübingen, Tübingen, Germany. olaf.heidenreich@uni-tuebingen.de
authors.forename: Olaf
authors.initials: O
authors.lastname: Heidenreich
authors.forename: Jürgen
authors.initials: J
authors.lastname: Krauter
authors.forename: Heidemarie
authors.initials: H
authors.lastname: Riehle
authors.forename: Philipp
authors.initials: P
authors.lastname: Hadwiger
authors.forename: Matthias
authors.initials: M
authors.lastname: John
authors.forename: Gerhard
authors.initials: G
authors.lastname: Heil
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Vornlocher
authors.forename: Alfred
authors.initials: A
authors.lastname: Nordheim
mesh_terms: D000208:Acute Disease; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000096:biosynthesis / Q000235:genetics; D039481:CD11b Antigen / Q000096:biosynthesis / Q000235:genetics; D002454:Cell Differentiation; D048429:Cell Size / Q000187:drug effects; D002762:Cholecalciferol / Q000494:pharmacology; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics; D050676:Core Binding Factor Alpha 2 Subunit; D015195:Drug Design; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects; D006801:Humans; D007951:Leukemia, Myeloid / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D015514:Oncogene Proteins, Fusion / Q000037:antagonists & inhibitors* / Q000235:genetics; D034622:RNA Interference; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000502:physiology*; D000075142:RUNX1 Translocation Partner 1 Protein; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000235:genetics; D014157:Transcription Factors / Q000037:antagonists & inhibitors* / Q000235:genetics; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D053773:Transforming Growth Factor beta1; D014178:Translocation, Genetic; D014407:Tumor Cells, Cultured / Q000378:metabolism / Q000648:ultrastructure; D014410:Tumor Stem Cell Assay
chemical_list: C107844:AML1-ETO fusion protein, human; D022763:CCAAT-Enhancer-Binding Protein-alpha; D039481:CD11b Antigen; D050676:Core Binding Factor Alpha 2 Subunit; D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D000075142:RUNX1 Translocation Partner 1 Protein; C508960:TGFB1 protein, human; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D002762:Cholecalciferol; D016186:Receptor, Macrophage Colony-Stimulating Factor