Genome-wide pattern of TCF7L2/TCF4 chromatin occupancy in colorectal cancer cells

Mol Cell Biol. 2008 Apr;28(8):2732-44. doi: 10.1128/MCB.02175-07. Epub 2008 Feb 11.

Abstract

Wnt signaling activates gene expression through the induced formation of complexes between DNA-binding T-cell factors (TCFs) and the transcriptional coactivator beta-catenin. In colorectal cancer, activating Wnt pathway mutations transform epithelial cells through the inappropriate activation of a TCF7L2/TCF4 target gene program. Through a DNA array-based genome-wide analysis of TCF4 chromatin occupancy, we have identified 6,868 high-confidence TCF4-binding sites in the LS174T colorectal cancer cell line. Most TCF4-binding sites are located at large distances from transcription start sites, while target genes are frequently "decorated" by multiple binding sites. Motif discovery algorithms define the in vivo-occupied TCF4-binding site as evolutionarily conserved A-C/G-A/T-T-C-A-A-A-G motifs. The TCF4-binding regions significantly correlate with Wnt-responsive gene expression profiles derived from primary human adenomas and often behave as beta-catenin/TCF4-dependent enhancers in transient reporter assays.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites
  • Cell Line, Tumor
  • Chromatin / genetics*
  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / metabolism*
  • DNA / metabolism
  • Gene Expression Regulation, Neoplastic
  • Genome, Human / genetics*
  • Humans
  • Protein Binding
  • TCF Transcription Factors / genetics*
  • TCF Transcription Factors / metabolism*
  • Transcription Factor 7-Like 2 Protein
  • Transcription, Genetic / genetics
  • Wnt Proteins / metabolism

Substances

  • Chromatin
  • TCF Transcription Factors
  • TCF7L2 protein, human
  • Transcription Factor 7-Like 2 Protein
  • Wnt Proteins
  • DNA