Reversal of epigenetic silencing of AP-2alpha results in increased zinc uptake in DU-145 and LNCaP prostate cancer cells

Carcinogenesis. 2011 Dec;32(12):1773-81. doi: 10.1093/carcin/bgr212. Epub 2011 Sep 22.

Abstract

Zinc accumulation is lost during prostate carcinogenesis. Recent studies reveal a strong association between prostate cancer progression and the downregulation of the zinc uptake transporters hZip1 and hZip3. The aim of this work was to assess the involvement of epigenetic processes in the disruption of zinc uptake homeostasis in prostate adenocarcinoma. In this report, we demonstrate an increase in hZip1 and hZip3 zinc transporters' expression and zinc uptake by the prostate cancer cells DU-145 and LNCaP in response to 5-aza-2'-deoxycytidine. This effect is due to demethylation of the promoter region of the activator protein (AP)-2alpha protein, which is crucial for hZip1 and hZip3 genes expression. Loss of AP-2alpha expression in DU-145 and LNCaP prostate cancer cells is due to hypermethylation of its promoter region. Similarly, we found higher AP-2alpha promoter methylation levels in clinical samples of early-stage prostate adenocarcinoma when compared with adjacent non-malignant prostate tissue. Taken together, our findings provide a better understanding of the epigenetic mechanisms that are involved in the loss of AP-2alpha protein in prostate cancer cells which lead to decreased cellular zinc uptake-a sine qua non of prostate cancer development.

Publication types

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

MeSH terms

  • Azacitidine / analogs & derivatives
  • Azacitidine / pharmacology
  • Base Sequence
  • Cation Transport Proteins / metabolism
  • Cell Line, Tumor
  • Chromatin Immunoprecipitation
  • DNA Methylation
  • DNA Primers
  • Decitabine
  • Epigenesis, Genetic*
  • Gene Silencing*
  • Humans
  • Male
  • Promoter Regions, Genetic
  • Prostatic Neoplasms / genetics*
  • Prostatic Neoplasms / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription Factor AP-2 / genetics
  • Transcription Factor AP-2 / physiology*
  • Transcription, Genetic
  • Zinc / metabolism*

Substances

  • Cation Transport Proteins
  • DNA Primers
  • SLC39A1 protein, human
  • SLC39A3 protein, human
  • Transcription Factor AP-2
  • Decitabine
  • Zinc
  • Azacitidine