Anti-androgens and the mutated androgen receptor of LNCaP cells: differential effects on binding affinity, heat-shock protein interaction, and transcription activation

Biochemistry. 1992 Mar 3;31(8):2393-9. doi: 10.1021/bi00123a026.


Previous studies from this laboratory have described that LNCaP prostate tumor cells contain an androgen receptor (AR) with a point mutation in the steroid-binding domain (codon 868, Thr to Ala). This defect leads to a change in specificity of the AR. Estrogens, progestagens, and some anti-androgens (e.g., cyproterone acetate, hydroxyflutamide, nilutamide) stimulate LNCaP cell growth rate through the AR. The present studies indicate that not all anti-androgens showed agonistic effects with the mutated receptor. The growth rate of LNCaP cells did not increase with the anti-androgen ICI 176334, nor could this compound increase transcription activation of the reporter gene construct via the mutant receptor in a cotransfection system [HeLa cell cotransfection system with an androgen-regulated reporter gene construct (pG29G-tk-CAT) and the mutant receptor as trans-vector]. Interaction of the AR of LNCaP cells with heat-shock proteins was studied by isolation of the receptor with a specific monoclonal antibody and characterization of associated proteins. Hsp90, hsp70, and hsp56 were found to coprecipitate with the AR. Incubation of the cells at 37 degrees C with androgen (R1881, 10 nM) or the anti-androgen hydroxyflutamide, prior to receptor isolation, resulted in dissociation of the AR-heat-shock protein complex. This dissociation is paralleled by the transformation to a tight nuclear-binding form of the AR. In contrast, ICI 176334 could not induce a release of heat-shock proteins and did not increase nuclear binding, but inhibited the transformation process induced by R1881.(ABSTRACT TRUNCATED AT 250 WORDS)

MeSH terms

  • Androgen Antagonists / pharmacology*
  • Cell Division
  • Cell Nucleus / metabolism
  • Chloramphenicol O-Acetyltransferase / biosynthesis
  • Chloramphenicol O-Acetyltransferase / genetics
  • Gene Expression Regulation, Neoplastic*
  • HeLa Cells
  • Heat-Shock Proteins / genetics*
  • Heat-Shock Proteins / metabolism
  • Humans
  • Male
  • Mutation*
  • Prostatic Neoplasms / chemistry
  • Prostatic Neoplasms / genetics*
  • Protein Binding
  • Receptors, Androgen / drug effects
  • Receptors, Androgen / genetics*
  • Transcription, Genetic*
  • Tumor Cells, Cultured


  • Androgen Antagonists
  • Heat-Shock Proteins
  • Receptors, Androgen
  • Chloramphenicol O-Acetyltransferase