SPROUTY-2 represses the epithelial phenotype of colon carcinoma cells via upregulation of ZEB1 mediated by ETS1 and miR-200/miR-150

Oncogene. 2016 Jun 9;35(23):2991-3003. doi: 10.1038/onc.2015.366. Epub 2015 Oct 12.

Abstract

SPROUTY-2 (SPRY2) is a modulator of tyrosine kinase receptor signaling with receptor- and cell type-dependent inhibitory or enhancing effects. Studies on the action of SPRY2 in major cancers are conflicting and its role remains unclear. Here we have dissected SPRY2 action in human colon cancer. Global transcriptomic analyses show that SPRY2 downregulates genes encoding tight junction proteins such as claudin-7 and occludin and other cell-to-cell and cell-to-matrix adhesion molecules in human SW480-ADH colon carcinoma cells. Moreover, SPRY2 represses LLGL2/HUGL2, PATJ1/INADL and ST14, main regulators of the polarized epithelial phenotype, and ESRP1, an epithelial-to-mesenchymal transition (EMT) inhibitor. A key action of SPRY2 is the upregulation of the major EMT inducer ZEB1, as these effects are reversed by ZEB1 knock-down by means of RNA interference. Consistently, we found an inverse correlation between the expression level of claudin-7 and those of SPRY2 and ZEB1 in human colon tumors. Mechanistically, ZEB1 upregulation by SPRY2 results from the combined induction of ETS1 transcription factor and the repression of microRNAs (miR-200 family, miR-150) that target ZEB1 RNA. Moreover, SPRY2 increased AKT activation by epidermal growth factor, whereas AKT and also Src inhibition reduced the induction of ZEB1. Altogether, these data suggest that AKT and Src are implicated in SPRY2 action. Collectively, these results show a tumorigenic role of SPRY2 in colon cancer that is based on the dysregulation of tight junction and epithelial polarity master genes via upregulation of ZEB1. The dissection of the mechanism of action of SPRY2 in colon cancer cells is important to understand the upregulation of this gene in a subset of patients with this neoplasia that have poor prognosis.

Publication types

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

MeSH terms

  • Cell Adhesion / genetics
  • Cell Line, Tumor
  • Cell Polarity / genetics
  • Cell Proliferation / physiology
  • Colonic Neoplasms / genetics
  • Colonic Neoplasms / metabolism*
  • Colonic Neoplasms / pathology
  • Epithelial Cells
  • HEK293 Cells
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Phenotype
  • Proto-Oncogene Protein c-ets-1 / genetics
  • Proto-Oncogene Protein c-ets-1 / metabolism*
  • Signal Transduction
  • Transfection
  • Up-Regulation
  • Zinc Finger E-box-Binding Homeobox 1 / genetics
  • Zinc Finger E-box-Binding Homeobox 1 / metabolism*

Substances

  • ETS1 protein, human
  • Intracellular Signaling Peptides and Proteins
  • MIRN150 microRNA, human
  • MIRN200 microRNA, human
  • Membrane Proteins
  • MicroRNAs
  • Proto-Oncogene Protein c-ets-1
  • SPRY2 protein, human
  • ZEB1 protein, human
  • Zinc Finger E-box-Binding Homeobox 1