TCF4 and CDX2, major transcription factors for intestinal function, converge on the same cis-regulatory regions

Proc Natl Acad Sci U S A. 2010 Aug 24;107(34):15157-62. doi: 10.1073/pnas.1003822107. Epub 2010 Aug 9.

Abstract

Surprisingly few pathways signal between cells, raising questions about mechanisms for tissue-specific responses. In particular, Wnt ligands signal in many mammalian tissues, including the intestinal epithelium, where constitutive signaling causes cancer. Genome-wide analysis of DNA cis-regulatory regions bound by the intestine-restricted transcription factor CDX2 in colonic cells uncovered highly significant overrepresentation of sequences that bind TCF4, a transcriptional effector of intestinal Wnt signaling. Chromatin immunoprecipitation confirmed TCF4 occupancy at most such sites and co-occupancy of CDX2 and TCF4 across short distances. A region spanning the single nucleotide polymorphism rs6983267, which lies within a MYC enhancer and confers colorectal cancer risk in humans, represented one of many co-occupied sites. Co-occupancy correlated with intestine-specific gene expression and CDX2 loss reduced TCF4 binding. These results implicate CDX2 in directing TCF4 binding in intestinal cells. Co-occupancy of regulatory regions by signal-effector and tissue-restricted transcription factors may represent a general mechanism for ubiquitous signaling pathways to achieve tissue-specific outcomes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / metabolism*
  • Binding Sites / genetics
  • CDX2 Transcription Factor
  • Caco-2 Cells
  • Colonic Neoplasms / genetics
  • Colonic Neoplasms / metabolism
  • Genetic Complementation Test
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • Humans
  • Intestinal Mucosa / metabolism*
  • Molecular Sequence Data
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Neoplasm / genetics
  • RNA, Neoplasm / metabolism
  • Regulatory Sequences, Nucleic Acid
  • Signal Transduction
  • Transcription Factor 4
  • Transcription Factors / metabolism*
  • Wnt Proteins / metabolism

Substances

  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • CDX2 Transcription Factor
  • CDX2 protein, human
  • Homeodomain Proteins
  • RNA, Messenger
  • RNA, Neoplasm
  • TCF4 protein, human
  • Transcription Factor 4
  • Transcription Factors
  • Wnt Proteins

Associated data

  • GEO/GSE22572