TGF-β drives epithelial-mesenchymal transition through δEF1-mediated downregulation of ESRP

Oncogene. 2012 Jun 28;31(26):3190-201. doi: 10.1038/onc.2011.493. Epub 2011 Oct 31.

Abstract

Epithelial-mesenchymal transition (EMT) is a crucial event in wound healing, tissue repair and cancer progression in adult tissues. We have recently shown that transforming growth factor (TGF)-β-induced EMT involves isoform switching of fibroblast growth factor receptors by alternative splicing. We performed a microarray-based analysis at single exon level to elucidate changes in splicing variants generated during TGF-β-induced EMT, and found that TGF-β induces broad alteration of splicing patterns by downregulating epithelial splicing regulatory proteins (ESRPs). This was achieved by TGF-β-mediated upregulation of δEF1 family proteins, δEF1 and SIP1. δEF1 and SIP1 each remarkably repressed ESRP2 transcription through binding to the ESRP2 promoter in NMuMG cells. Silencing of both δEF1 and SIP1, but not either alone, abolished the TGF-β-induced ESRP repression. The expression profiles of ESRPs were inversely related to those of δEF1 and SIP in human breast cancer cell lines and primary tumor specimens. Further, overexpression of ESRPs in TGF-β-treated cells resulted in restoration of the epithelial splicing profiles as well as attenuation of certain phenotypes of EMT. Therefore, δEF1 family proteins repress the expression of ESRPs to regulate alternative splicing during TGF-β-induced EMT and the progression of breast cancers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing / drug effects
  • Animals
  • Breast Neoplasms / pathology
  • Cadherins / genetics
  • Cell Line, Tumor
  • Disease Progression
  • Down-Regulation / drug effects*
  • Down-Regulation / genetics
  • Epithelial-Mesenchymal Transition / drug effects*
  • Epithelial-Mesenchymal Transition / genetics
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene Expression Regulation, Neoplastic / genetics
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • Humans
  • Mice
  • Nerve Tissue Proteins / genetics
  • Phenotype
  • Protein Isoforms / genetics
  • RNA-Binding Proteins / genetics*
  • RNA-Binding Proteins / metabolism*
  • Receptors, Fibroblast Growth Factor / genetics
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transforming Growth Factor beta / pharmacology*
  • Zinc Finger E-box-Binding Homeobox 1

Substances

  • Cadherins
  • ESRP1 protein, human
  • GEMIN2 protein, human
  • Homeodomain Proteins
  • Nerve Tissue Proteins
  • Protein Isoforms
  • RNA-Binding Proteins
  • Receptors, Fibroblast Growth Factor
  • Transcription Factors
  • Transforming Growth Factor beta
  • ZEB1 protein, human
  • Zinc Finger E-box-Binding Homeobox 1