VHL promotes E2 box-dependent E-cadherin transcription by HIF-mediated regulation of SIP1 and snail

Mol Cell Biol. 2007 Jan;27(1):157-69. doi: 10.1128/MCB.00892-06. Epub 2006 Oct 23.

Abstract

The product of the von Hippel-Lindau gene (VHL) acts as the substrate-recognition component of an E3 ubiquitin ligase complex that ubiquitylates the catalytic alpha subunit of hypoxia-inducible factor (HIF) for oxygen-dependent destruction. Although emerging evidence supports the notion that deregulated accumulation of HIF upon the loss of VHL is crucial for the development of clear-cell renal cell carcinoma (CC-RCC), the molecular events downstream of HIF governing renal oncogenesis remain unclear. Here, we show that the expression of a homophilic adhesion molecule, E-cadherin, a major constituent of epithelial cell junctions whose loss is associated with the progression of epithelial cancers, is significantly down-regulated in primary CC-RCC and CC-RCC cell lines devoid of VHL. Reintroduction of wild-type VHL in CC-RCC (VHL(-/-)) cells markedly reduced the expression of E2 box-dependent E-cadherin-specific transcriptional repressors Snail and SIP1 and concomitantly restored E-cadherin expression. RNA interference-mediated knockdown of HIFalpha in CC-RCC (VHL(-/-)) cells likewise increased E-cadherin expression, while functional hypoxia or expression of VHL mutants incapable of promoting HIFalpha degradation attenuated E-cadherin expression, correlating with the disengagement of RNA polymerase II from the endogenous E-cadherin promoter/gene. These findings reveal a critical HIF-dependent molecular pathway connecting VHL, an established "gatekeeper" of the renal epithelium, with a major epithelial tumor suppressor, E-cadherin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cadherins / biosynthesis*
  • Cadherins / genetics
  • Cadherins / metabolism
  • Cell Line, Tumor
  • Epithelial Cells / metabolism
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Kidney / metabolism
  • Nerve Tissue Proteins / physiology*
  • Promoter Regions, Genetic
  • RNA Interference
  • RNA Polymerase II / metabolism
  • RNA, Small Interfering / metabolism
  • RNA-Binding Proteins / physiology*
  • Snail Family Transcription Factors
  • Subcellular Fractions / metabolism
  • Transcription Factors / physiology*
  • Von Hippel-Lindau Tumor Suppressor Protein / physiology*

Substances

  • Cadherins
  • GEMIN2 protein, human
  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Nerve Tissue Proteins
  • RNA, Small Interfering
  • RNA-Binding Proteins
  • Snail Family Transcription Factors
  • Transcription Factors
  • Von Hippel-Lindau Tumor Suppressor Protein
  • RNA Polymerase II
  • VHL protein, human