The class I bHLH factors E2-2A and E2-2B regulate EMT

J Cell Sci. 2009 Apr 1;122(Pt 7):1014-24. doi: 10.1242/jcs.028241.

Abstract

Functional loss of the cell-cell adhesion molecule E-cadherin is an essential event for epithelial-mesenchymal transition (EMT), a process that allows cell migration during embryonic development and tumour invasion. In most carcinomas, transcriptional repression has emerged as the main mechanism responsible for E-cadherin downregulation. Here, we report the identification of class I bHLH factor E2-2 (TCF4/ITF2) as a new EMT regulator. Both isoforms of E2-2 (E2-2A and E2-2B) induce a full EMT when overexpressed in MDCK cells but without affecting the tumorigenic properties of parental cells, in contrast to other EMT inducers, such as Snail1 or class I bHLH E47. E-cadherin repression mediated by E2-2 is indirect and independent of proximal E-boxes of the promoter. Knockdown studies indicate that E2-2 expression is dispensable for maintenance of the EMT driven by Snail1 and E47. Comparative gene-profiling analysis reveals that E2-2 factors induce similar, yet distinct, genetic programs to that induced by E47 in MDCK cells. These results, together with the embryonic expression pattern of Tcf4 and E2A (which encodes E12/E47), support a distinct role for E2-2 and suggest an interesting interplay between E-cadherin repressors in the regulation of physiological and pathological EMT processes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Cadherins / genetics
  • Cadherins / metabolism
  • Carcinoma, Squamous Cell / metabolism
  • Carcinoma, Squamous Cell / pathology
  • Cell Line, Tumor
  • Cell Movement
  • Dogs
  • Embryo, Mammalian / metabolism
  • Epithelial Cells / cytology
  • Epithelial Cells / metabolism
  • Epithelium / metabolism*
  • Gene Expression Profiling
  • Humans
  • Mesoderm / embryology
  • Mesoderm / metabolism*
  • Mice
  • Neoplasm Invasiveness
  • Promoter Regions, Genetic / genetics
  • RNA, Small Interfering / metabolism
  • Snail Family Transcription Factors
  • TCF Transcription Factors / genetics
  • TCF Transcription Factors / metabolism*
  • Transcription Factor 7-Like 1 Protein
  • Transcription Factor 7-Like 2 Protein
  • Transcription Factors / metabolism
  • Transcription, Genetic
  • Up-Regulation

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Cadherins
  • RNA, Small Interfering
  • SNAI1 protein, human
  • Snai1 protein, mouse
  • Snail Family Transcription Factors
  • TCF Transcription Factors
  • TCF7L1 protein, human
  • TCF7L2 protein, human
  • Tcf7l1 protein, mouse
  • Tcf7l2 protein, mouse
  • Transcription Factor 7-Like 1 Protein
  • Transcription Factor 7-Like 2 Protein
  • Transcription Factors