Deoxyribonucleic acid triplex formation inhibits granulocyte macrophage colony-stimulating factor gene expression and suppresses growth in juvenile myelomonocytic leukemic cells

J Clin Invest. 1997 Jun 15;99(12):3000-8. doi: 10.1172/JCI119495.

Abstract

Juvenile myelomonocytic leukemia (JMML) is a severe childhood malignancy. The autocrine production of GMCSF is believed to be responsible for the spontaneous proliferation of JMML cells. A nuclear factor-kappaB (NF-kappaB)/Rel binding site within the GM-CSF gene promoter, termed the kappaB element, plays an important role in controlling transcription from the GM-CSF gene. We investigated the effect of an oligonucleotide GM3, directed to form a DNA triple helix across this kappaB element, on growth and GM-CSF production by JMML cells. Treatment of these cells, either unstimulated or induced by TNFalpha, with GM3 led to a significant and specific inhibition of both GM-CSF production and spontaneous colony formation. This constitutes the first report linking specific triplex-mediated inhibition of gene transcription with a functional outcome; i.e., cell growth. We observed the constitutive presence of NF-kappaB/Rel proteins in the nucleus of JMML cells. The constitutive and TNFalpha-induced NF-kappaB/Rel complexes were identical and were composed mainly of p50 and c-Rel proteins. Treatment of the cells with a neutralizing anti-TNFalpha monoclonal antibody completely abrogated constitutive nuclear expression of NF-kappaB/Rel proteins. These results indicate that the aberrant, constitutive GM-CSF gene activation in JMML is maintained by TNFalpha-mediated activation of NF-kappaB/Rel proteins. Our findings identify the molecular basis for the autocrine TNFalpha activation of the GM-CSF gene in JMML and suggest potential novel and specific approaches for the treatment of this aggressive childhood leukemia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Cell Division
  • Cell Nucleus / chemistry
  • Child, Preschool
  • DNA / chemistry*
  • DNA / metabolism
  • Gene Expression*
  • Granulocyte-Macrophage Colony-Stimulating Factor / genetics*
  • Humans
  • Infant
  • Leukemia, Myelomonocytic, Chronic / genetics
  • Leukemia, Myelomonocytic, Chronic / pathology*
  • NF-kappa B / analysis
  • NF-kappa B / metabolism
  • Nucleic Acid Conformation*
  • Oligodeoxyribonucleotides / chemistry
  • Oligodeoxyribonucleotides / pharmacology
  • Promoter Regions, Genetic
  • Sp1 Transcription Factor / metabolism
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • NF-kappa B
  • Oligodeoxyribonucleotides
  • Sp1 Transcription Factor
  • Tumor Necrosis Factor-alpha
  • triplex DNA
  • Granulocyte-Macrophage Colony-Stimulating Factor
  • DNA