Chimeric molecules facilitate the degradation of androgen receptors and repress the growth of LNCaP cells

Asian J Androl. 2009 Jan;11(1):119-26. doi: 10.1038/aja.2008.26. Epub 2008 Dec 15.

Abstract

Post-translational degradation of protein plays an important role in cell life. We employed chimeric molecules (dihydrotestosterone-based proteolysis-targeting chimeric molecule [DHT-PROTAC]) to facilitate androgen receptor (AR) degradation via the ubiquitin-proteasome pathway (UPP) and to investigate the role of AR in cell proliferation and viability in androgen-sensitive prostate cancer cells. Western blot analysis and immunohistochemistry were applied to analyse AR levels in LNCaP cells after DHT-PROTAC treatment. Cell counting and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) cell viability assay were used to evaluate cell proliferation and viability after AR elimination in both LNCaP and PC-3 cells. AR was tagged for elimination via the UPP by DHT-PROTAC, and this could be blocked by proteasome inhibitors. Degradation of AR depended on DHT-PROTAC concentration, and either DHT or an ALAPYIP-(arg)(8) peptide could compete with DHT-PROTAC. Inhibition of cell proliferation and decreased viability were observed in LNCaP cells, but not in PC-3 or 786-O cells after DHT-PROTAC treatment. These data indicate that AR elimination is facilitated via the UPP by DHT-PROTAC, and that the growth of LNCaP cells is repressed after AR degradation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Cell Proliferation / drug effects*
  • Cell Survival / drug effects
  • Dihydrotestosterone / pharmacology
  • Dose-Response Relationship, Drug
  • Humans
  • Male
  • Prostatic Neoplasms / drug therapy
  • Prostatic Neoplasms / metabolism*
  • Prostatic Neoplasms / pathology*
  • Proteasome Endopeptidase Complex / metabolism
  • Receptors, Androgen / metabolism*
  • Recombinant Fusion Proteins / pharmacology*
  • Recombinant Fusion Proteins / therapeutic use
  • Signal Transduction / drug effects
  • Ubiquitin / metabolism

Substances

  • Receptors, Androgen
  • Recombinant Fusion Proteins
  • Ubiquitin
  • Dihydrotestosterone
  • Proteasome Endopeptidase Complex