Repression of vascular endothelial growth factor expression by the runt-related transcription factor 1 in acute myeloid leukemia

Cancer Res. 2011 Apr 1;71(7):2761-71. doi: 10.1158/0008-5472.CAN-10-0402. Epub 2011 Mar 29.

Abstract

VEGFA is considered one of the most important regulators of tumor-associated angiogenesis in cancer. In acute myeloid leukemia (AML) VEGFA is an independent prognostic factor for reduced overall and relapse-free survival. Transcriptional activation of the VEGFA promoter, a core mechanism for VEGFA regulation, has not been fully elucidated. We found a significant (P < 0.0001) inverse correlation between expression of VEGFA and AML1/RUNX1 in a large set of gene expression array data. Strikingly, highest VEGFA levels were demonstrated in AML blasts containing a t(8;21) translocation, which involves the AML1/RUNX1 protein (AML1/ETO). Overexpression of AML1/RUNX1 led to downregulation of VEGFA expression, whereas blocking of AML1/RUNX1 with siRNAs resulted in increased VEGFA expression. Cotransfection of AML1/RUNX1 and VEGFA promoter luciferase promoter constructs resulted in a decrease in VEGFA promoter activity. ChIP analysis shows a direct binding of AML1/RUNX1 to the promoter of VEGFA on three AML1/RUNX1 binding sites. Silencing of AML1/ETO caused a decrease in VEGFA mRNA expression and a decrease in secreted VEGFA protein levels in AML1/ETO-positive Kasumi-1 cells. Taken together, these data pinpoint to a model whereby in normal cells AML1/RUNX1 acts as a repressor for VEGFA, while in AML cells VEGFA expression is upregulated due to AML1/RUNX1 aberrations, for example, AML1/ETO. In conclusion, these observations give insight in the regulation of VEGFA at the mRNA level in AML.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Cell Line, Tumor
  • Chromosomes, Human, Pair 21
  • Chromosomes, Human, Pair 8
  • Core Binding Factor Alpha 2 Subunit / biosynthesis*
  • Core Binding Factor Alpha 2 Subunit / genetics
  • Down-Regulation
  • Gene Expression Regulation, Neoplastic
  • Gene Knockdown Techniques
  • Gene Silencing
  • HL-60 Cells
  • Humans
  • Leukemia, Myeloid, Acute / genetics
  • Leukemia, Myeloid, Acute / metabolism*
  • Mutation
  • Promoter Regions, Genetic
  • Proto-Oncogene Proteins / biosynthesis
  • Proto-Oncogene Proteins / genetics
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • RUNX1 Translocation Partner 1 Protein
  • Transcription Factors / biosynthesis
  • Transcription Factors / genetics
  • Transcription, Genetic
  • Translocation, Genetic
  • Up-Regulation
  • Vascular Endothelial Growth Factor A / antagonists & inhibitors
  • Vascular Endothelial Growth Factor A / biosynthesis*
  • Vascular Endothelial Growth Factor A / genetics

Substances

  • Core Binding Factor Alpha 2 Subunit
  • Proto-Oncogene Proteins
  • RNA, Messenger
  • RUNX1 Translocation Partner 1 Protein
  • RUNX1 protein, human
  • RUNX1T1 protein, human
  • Transcription Factors
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A