Enhancement of GLI1-transcriptional activity by beta-catenin in human cancer cells

Oncol Rep. 2006 Jul;16(1):91-6.

Abstract

The Hedgehog (Hh) signaling pathway and the Wnt signaling pathway are known to play important roles in carcinogenesis and the progression of various human malignant tumors. Although a relationship between these two pathways has recently been reported, the mechanism by which beta-catenin, one of the key molecules of the Wnt signaling pathway, influences the Hh pathway has not yet been revealed in detail. To clarify the role of beta-catenin in relation to the Hh signaling pathway, we transfected GLI1 and beta-catenin expression constructs into human malignant cells, including stomach, colon, and lung cancers, and evaluated the luciferase activity of GLI-responsive reporter constructs. While exogenous GLI1 increased the luciferase activity, exogenous beta-catenin also enhanced the activity under overexpression of GLI1. However, co-transfection with T-cell factor (TCF)-4 or lymphocyte enhancer factor (LEF)-1 did not influence the activity, indicating that the enhancement of beta-catenin in relation to the Hh signaling pathway is not TCF/LEF-dependent. Our results suggest that beta-catenin might be involved in the Hh signaling pathway via enhancement of the transcriptional activity of GLI.

MeSH terms

  • Cell Line, Tumor
  • Gene Expression Regulation, Neoplastic*
  • Genes, Reporter
  • Hedgehog Proteins
  • Humans
  • Luciferases / metabolism
  • Lymphoid Enhancer-Binding Factor 1 / metabolism
  • Oncogene Proteins / genetics*
  • Oncogene Proteins / physiology*
  • Signal Transduction
  • TCF Transcription Factors / metabolism
  • Trans-Activators / genetics*
  • Trans-Activators / metabolism
  • Trans-Activators / physiology*
  • Transcription, Genetic*
  • Wnt Proteins / metabolism
  • Zinc Finger Protein GLI1
  • beta Catenin / metabolism*

Substances

  • Hedgehog Proteins
  • Lymphoid Enhancer-Binding Factor 1
  • Oncogene Proteins
  • TCF Transcription Factors
  • Trans-Activators
  • Wnt Proteins
  • Zinc Finger Protein GLI1
  • beta Catenin
  • Luciferases