title: Embryonic lethality and impairment of haematopoiesis in mice heterozygous for an AML1-ETO fusion gene.
abstract: Acute myeloid leukaemia (AML) is a major haematopoietic malignancy characterized by the proliferation of a malignant clone of myeloid progenitor cells. A reciprocal translocation, t(8;21)(q22;q22), observed in the leukaemic cells of approximately 40% of patients with the M2 subtype of AML disrupts both the AML1 (CBFA2) gene on chromosome 21 and the ETO (MTG8) gene on chromosome 8 (refs 3-5). A chimaeric protein is synthesized from one of the derivative chromosomes that contains the N terminus of the AML1 transcription factor, including its DNA-binding domain, fused to most of ETO, a protein of unknown function. We generated mice that mimic human t(8;21) with a "knock-in' strategy. Mice heterozygous for an AML1-ETO allele (AML1-ETO/+) die in midgestation from haemorrhaging in the central nervous system and exhibit a severe block in fetal liver haematopoiesis. This phenotype is very similar to that resulting from homozygous disruption of the AML1 (Cbfa2) or Cbfb genes, indicating that AML1-ETO blocks normal AML1 function. However, yolk sac cells from AML1-ETO/+ mice differentiated into macrophages in haematopoietic colony forming unit (CFU) assays, unlike Cbfa2-/- or Cbfb-/-cells, which form no colonies in vitro. This indicates that AML1-ETO may have other functions besides blocking wild-type AML1, a property that may be important in leukaemogenesis.
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Yergeau
authors.forename: C J
authors.initials: CJ
authors.lastname: Hetherington
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.forename: P
authors.initials: P
authors.lastname: Zhang
authors.forename: A H
authors.initials: AH
authors.lastname: Sharpe
authors.forename: M
authors.initials: M
authors.lastname: Binder
authors.forename: M
authors.initials: M
authors.lastname: Marín-Padilla
authors.forename: D G
authors.initials: DG
authors.lastname: Tenen
authors.forename: N A
authors.initials: NA
authors.lastname: Speck
authors.forename: D E
authors.initials: DE
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002678:Chimera; D002874:Chromosome Mapping; D002891:Chromosomes, Human, Pair 21; D002898:Chromosomes, Human, Pair 8; D003001:Cloning, Molecular; D050676:Core Binding Factor Alpha 2 Subunit; D003433:Crosses, Genetic; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D005091:Exons; D005260:Female; D005313:Fetal Death / Q000235:genetics*; D006580:Genetic Carrier Screening; D006410:Hematopoiesis / Q000235:genetics*; D006801:Humans; D007951:Leukemia, Myeloid / Q000235:genetics; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D011518:Proto-Oncogene Proteins; D000075142:RUNX1 Translocation Partner 1 Protein; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*; D014178:Translocation, Genetic; D015017:Yolk Sac
chemical_list: D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D000075142:RUNX1 Translocation Partner 1 Protein; C493728:RUNX1 protein, human; C082222:RUNX1T1 protein, human; C493726:Runx1 protein, mouse; D014157:Transcription Factors