β-catenin-independent regulation of Wnt target genes by RoR2 and ATF2/ATF4 in colon cancer cells

Sci Rep. 2018 Feb 16;8(1):3178. doi: 10.1038/s41598-018-20641-5.

Abstract

Wnt signaling is an evolutionarily conserved signaling route required for development and homeostasis. While canonical, β-catenin-dependent Wnt signaling is well studied and has been linked to many forms of cancer, much less is known about the role of non-canonical, β-catenin-independent Wnt signaling. Here, we aimed at identifying a β-catenin-independent Wnt target gene signature in order to understand the functional significance of non-canonical signaling in colon cancer cells. Gene expression profiling was performed after silencing of key components of Wnt signaling pathway and an iterative signature algorithm was applied to predict pathway-dependent gene signatures. Independent experiments confirmed several target genes, including PLOD2, HADH, LCOR and REEP1 as non-canonical target genes in various colon cancer cells. Moreover, non-canonical Wnt target genes are regulated via RoR2, Dvl2, ATF2 and ATF4. Furthermore, we show that the ligands Wnt5a/b are upstream regulators of the non-canonical signature and moreover regulate proliferation of cancer cells in a β-catenin-independent manner. Our experiments indicate that colon cancer cells are dependent on both β-catenin-dependent and -independent Wnt signaling routes for growth and proliferation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activating Transcription Factor 2 / metabolism*
  • Activating Transcription Factor 4 / metabolism*
  • Cell Line, Tumor
  • Cell Proliferation
  • Colonic Neoplasms / pathology*
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Receptor Tyrosine Kinase-like Orphan Receptors / metabolism*
  • Wnt Proteins / metabolism*
  • Wnt Signaling Pathway
  • beta Catenin / metabolism

Substances

  • ATF2 protein, human
  • ATF4 protein, human
  • Activating Transcription Factor 2
  • Wnt Proteins
  • beta Catenin
  • Activating Transcription Factor 4
  • ROR2 protein, human
  • Receptor Tyrosine Kinase-like Orphan Receptors