HIV-1 protease inhibitor induces growth arrest and apoptosis of human prostate cancer LNCaP cells in vitro and in vivo in conjunction with blockade of androgen receptor STAT3 and AKT signaling

Cancer Sci. 2005 Jul;96(7):425-33. doi: 10.1111/j.1349-7006.2005.00063.x.

Abstract

This study found that the HIV-1 protease inhibitor nelfinavir (NFV) induced growth arrest and apoptosis of human prostate cancer cells (LNCaP, DU145 and PC-3 cells), as measured by MTT and terminal deoxyribonucleotide transferase-mediated dUTP nick end labeling (TUNEL) assays, respectively, on the third day of culture. In addition, NFV blocked androgen receptor (AR) signaling in association with downregulation of nuclear levels of AR in LNCaP cells as measured by reporter assay and western blot analysis. As expected, NFV downregulated the level of the AR target molecule prostate specific antigen in these cells. Moreover, NFV disrupted STAT3 signaling; protease inhibitors blocked interleukin-6-induced phosphorylation of STAT3 and inhibited STAT3 DNA binding activity in LNCaP and DU145 cells, as measured by western blot analysis and enzyme-linked immunosorbent assay (ELISA), respectively. Furthermore, NFV blocked AKT signaling in prostate cancer cells as measured by kinase assay with glycogen synthase kinase-3alpha/beta as a substrate. Importantly, NFV inhibited the proliferation of LNCaP cells presented as tumor xenografts in BALB/c nude mice without side-effects. Taken together, NFV inhibited the proliferation of prostate cancer cells in conjunction with blockade of signaling by AR, STAT3, and AKT, suggesting that this family of compounds might be useful for the treatment of individuals with prostate cancer.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Cell Line, Tumor
  • DNA-Binding Proteins / antagonists & inhibitors*
  • DNA-Binding Proteins / metabolism
  • Down-Regulation
  • HIV Protease Inhibitors / pharmacology*
  • Humans
  • In Vitro Techniques
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Nelfinavir / pharmacology*
  • Prostatic Neoplasms / drug therapy*
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors*
  • Protein-Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins / antagonists & inhibitors*
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-akt
  • Receptors, Androgen / drug effects*
  • STAT3 Transcription Factor
  • Signal Transduction / drug effects
  • Trans-Activators / antagonists & inhibitors*
  • Trans-Activators / metabolism

Substances

  • AR protein, human
  • DNA-Binding Proteins
  • HIV Protease Inhibitors
  • Proto-Oncogene Proteins
  • Receptors, Androgen
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • Stat3 protein, mouse
  • Trans-Activators
  • AKT1 protein, human
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • Nelfinavir