E-cadherin is a novel transcriptional target of the KLF6 tumor suppressor

Oncogene. 2006 Sep 28;25(44):6026-31. doi: 10.1038/sj.onc.1209611. Epub 2006 May 15.

Abstract

The tumor suppressor KLF6 is a member of the Krüppel-like family of transcription factors, which has been implicated in the pathogenesis of several human carcinomas. Uncovering the transcriptional targets relevant for its tumorigenic properties, including cellular proliferation and invasion, will be essential to understanding possible mechanisms by which KLF6 and its antagonistic splice form, KLF6-SV1, regulate this development. To begin defining possible metastatic-related pathways, we analysed the effect of KLF6 dysregulation on a recognized suppressor of cellular invasion, E-cadherin. Targeted KLF6 reduction in an ovarian cancer cell line, SKOV-3, resulted in a 50% reduction of E-cadherin expression (P<0.01) and conversely, KLF6-SV1 silencing upregulated E-cadherin approximately fivefold (P<0.0001). These changes resulted from KLF6 directly transactivating the E-cadherin promoter as demonstrated by luciferase promoter assay and chromatin immunoprecipitation (ChIP). KLF6-mediated changes in E-cadherin levels were accompanied by downstream changes in both the subcellular localization of beta-catenin and c-myc expression levels. Moreover, and consistent with these experimental findings, patient-derived epithelial ovarian tumors with low KLF6 and high KLF6-SV1 expression ratios had significantly decreased E-cadherin expression (P<0.0001). These combined findings highlight the E-cadherin pathway as a novel and functionally important mediator by which changes in KLF6 and KLF6-SV1 can directly alter ovarian tumor invasion and metastasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions / genetics
  • Cadherins / biosynthesis*
  • Cadherins / genetics*
  • Cadherins / physiology
  • Cell Line, Tumor
  • Female
  • Gene Expression Regulation, Neoplastic* / physiology
  • Growth Inhibitors / genetics
  • Growth Inhibitors / physiology
  • HeLa Cells
  • Humans
  • Kruppel-Like Factor 6
  • Kruppel-Like Transcription Factors / physiology*
  • Neoplasm Invasiveness / genetics
  • Neoplasm Metastasis / genetics
  • Ovarian Neoplasms / genetics*
  • Ovarian Neoplasms / metabolism*
  • Proto-Oncogene Proteins / physiology*
  • Proto-Oncogene Proteins c-myc / biosynthesis
  • Proto-Oncogene Proteins c-myc / genetics
  • Signal Transduction / genetics
  • Subcellular Fractions / metabolism
  • Transcription, Genetic*
  • Tumor Suppressor Proteins / physiology*
  • beta Catenin / biosynthesis
  • beta Catenin / genetics
  • beta Catenin / metabolism

Substances

  • 3' Untranslated Regions
  • Cadherins
  • Growth Inhibitors
  • KLF6 protein, human
  • Kruppel-Like Factor 6
  • Kruppel-Like Transcription Factors
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-myc
  • Tumor Suppressor Proteins
  • beta Catenin