Jade-1, a candidate renal tumor suppressor that promotes apoptosis

Proc Natl Acad Sci U S A. 2005 Aug 2;102(31):11035-40. doi: 10.1073/pnas.0500757102. Epub 2005 Jul 26.

Abstract

Medical therapies are lacking for advanced renal cancer, so there is a great need to understand its pathogenesis. Most renal cancers have defects in the von Hippel-Lindau tumor suppressor pVHL. The mechanism by which pVHL protein functions in renal tumor suppression remains unclear. Jade-1 is a short-lived, kidney-enriched transcription factor that is stabilized by direct interaction with pVHL. Loss of Jade-1 stabilization by pVHL correlates with renal cancer risk, making the relationship between Jade-1 and renal cancer compelling. We report that Jade-1 expression was barely detectable in all tested renal cancer cell lines, regardless of VHL status. Strikingly, proteasome inhibitor treatment increased endogenous Jade-1 expression up to 10-fold. Jade-1 inhibited renal cancer cell growth, colony formation, and tumor formation in nude mice. Intriguingly, Jade-1 also affected the pattern of cell growth in monolayer culture and 3D culture. Jade-1 increased apoptosis by 40-50% and decreased levels of antiapoptotic Bcl-2. Antisense Jade-1-expressing cells confirmed these results. Therefore, Jade-1 may suppress renal cancer cell growth in part by increasing apoptosis. Jade-1 may represent a proapoptotic barrier to proliferation that must be overcome generally in renal cancer, perhaps initially by pVHL inactivation and subsequently by increased proteasomal activity. Therefore, Jade-1 may be a renal tumor suppressor.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis
  • Cell Line, Tumor
  • DNA, Antisense / genetics
  • Gene Expression / drug effects
  • Genes, Tumor Suppressor
  • Homeodomain Proteins / genetics*
  • Homeodomain Proteins / physiology
  • Humans
  • Kidney Neoplasms / genetics*
  • Kidney Neoplasms / pathology*
  • Male
  • Mice
  • Mice, Nude
  • Protease Inhibitors / pharmacology
  • Tumor Suppressor Proteins / genetics*
  • Tumor Suppressor Proteins / physiology
  • Ubiquitin-Protein Ligases / genetics
  • Von Hippel-Lindau Tumor Suppressor Protein

Substances

  • DNA, Antisense
  • Homeodomain Proteins
  • JADE1 protein, human
  • Protease Inhibitors
  • Tumor Suppressor Proteins
  • Ubiquitin-Protein Ligases
  • Von Hippel-Lindau Tumor Suppressor Protein
  • VHL protein, human