Genomic DNA breakpoints in AML1/RUNX1 and ETO cluster with topoisomerase II DNA cleavage and DNase I hypersensitive sites in t(8;21) leukemia

Proc Natl Acad Sci U S A. 2002 Mar 5;99(5):3070-5. doi: 10.1073/pnas.042702899. Epub 2002 Feb 26.

Abstract

The translocation t(8;21)(q22;q22) is one of the most frequent chromosome translocations in acute myeloid leukemia (AML). AML1/RUNX1 at 21q22 is involved in t(8;21), t(3;21), and t(16;21) in de novo and therapy-related AML and myelodysplastic syndrome as well as in t(12;21) in childhood B cell acute lymphoblastic leukemia. Although DNA breakpoints in AML1 and ETO (at 8q22) cluster in a few introns, the mechanisms of DNA recombination resulting in t(8;21) are unknown. The correlation of specific chromatin structural elements, i.e., topoisomerase II (topo II) DNA cleavage sites, DNase I hypersensitive sites, and scaffold-associated regions, which have been implicated in chromosome recombination with genomic DNA breakpoints in AML1 and ETO in t(8;21) is unknown. The breakpoints in AML1 and ETO were clustered in the Kasumi 1 cell line and in 31 leukemia patients with t(8;21); all except one had de novo AML. Sequencing of the breakpoint junctions revealed no common DNA motif; however, deletions, duplications, microhomologies, and nontemplate DNA were found. Ten in vivo topo II DNA cleavage sites were mapped in AML1, including three in intron 5 and seven in intron 7a, and two were in intron 1b of ETO. All strong topo II sites colocalized with DNase I hypersensitive sites and thus represent open chromatin regions. These sites correlated with genomic DNA breakpoints in both AML1 and ETO, thus implicating them in the de novo 8;21 translocation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Binding Sites
  • Child
  • Chromosomes, Human, Pair 21*
  • Chromosomes, Human, Pair 8*
  • Cloning, Molecular
  • Core Binding Factor Alpha 2 Subunit
  • DNA Topoisomerases, Type II / metabolism*
  • DNA, Neoplasm / metabolism*
  • DNA-Binding Proteins / genetics*
  • Deoxyribonuclease I / metabolism*
  • Female
  • Humans
  • Leukemia, Myeloid / genetics*
  • Male
  • Middle Aged
  • Multigene Family
  • Neoplasm Proteins / genetics*
  • Proto-Oncogene Proteins / genetics*
  • RUNX1 Translocation Partner 1 Protein
  • Transcription Factors / genetics*
  • Translocation, Genetic*
  • Tumor Cells, Cultured

Substances

  • Core Binding Factor Alpha 2 Subunit
  • DNA, Neoplasm
  • DNA-Binding Proteins
  • Neoplasm Proteins
  • Proto-Oncogene Proteins
  • RUNX1 Translocation Partner 1 Protein
  • RUNX1 protein, human
  • RUNX1T1 protein, human
  • Transcription Factors
  • Deoxyribonuclease I
  • DNA Topoisomerases, Type II