FBI-1 functions as a novel AR co-repressor in prostate cancer cells

Cell Mol Life Sci. 2011 Mar;68(6):1091-103. doi: 10.1007/s00018-010-0511-7. Epub 2010 Sep 2.

Abstract

The pro-oncogene FBI-1, encoded by Zbtb7a, is a transcriptional repressor that belongs to the POK (POZ/BTB and Krüppel) protein family. In this study, we investigated a potential interaction between androgen receptor (AR) signaling and FBI-1 and demonstrated that overexpression of FBI-1 inhibited ligand-dependent AR activation. A protein-protein interaction was identified between FBI-1 and AR in a ligand-dependent manner. Furthermore, FBI-1, AR and SMRT formed a ternary complex and FBI-1 enhanced the recruitment of NCoR and SMRT to endogenous PSA upstream sequences. Our data also indicated that the FBI-1-mediated inhibition of AR transcriptional activity is partially dependent on HDAC. Interestingly, FBI-1 plays distinct roles in regulating LNCaP (androgen-dependent) and PC-3 cell (androgen-independent) proliferation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Chromatin Immunoprecipitation
  • DNA Primers / genetics
  • DNA-Binding Proteins / metabolism*
  • Histone Deacetylases / metabolism
  • Humans
  • Immunoprecipitation
  • Luciferases
  • Male
  • Multiprotein Complexes / metabolism*
  • Nuclear Receptor Co-Repressor 2 / metabolism*
  • Plasmids / genetics
  • Prostatic Neoplasms / metabolism*
  • RNA, Small Interfering / genetics
  • Receptors, Androgen / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / physiology*
  • Transcription Factors / metabolism*
  • Transfection

Substances

  • DNA Primers
  • DNA-Binding Proteins
  • Multiprotein Complexes
  • NCOR2 protein, human
  • Nuclear Receptor Co-Repressor 2
  • RNA, Small Interfering
  • Receptors, Androgen
  • Transcription Factors
  • ZBTB7A protein, human
  • Luciferases
  • Histone Deacetylases