Targeted methylation of the epithelial cell adhesion molecule (EpCAM) promoter to silence its expression in ovarian cancer cells

PLoS One. 2014 Jan 29;9(1):e87703. doi: 10.1371/journal.pone.0087703. eCollection 2014.

Abstract

The Epithelial Cell Adhesion Molecule (EpCAM) is overexpressed in many cancers including ovarian cancer and EpCAM overexpression correlates with decreased survival of patients. It was the aim of this study to achieve a targeted methylation of the EpCAM promoter and silence EpCAM gene expression using an engineered zinc finger protein that specifically binds the EpCAM promoter fused to the catalytic domain of the Dnmt3a DNA methyltransferase. We show that transient transfection of this construct increased the methylation of the EpCAM promoter in SKOV3 cells from 4-8% in untreated cells to 30%. Up to 48% methylation was observed in stable cell lines which express the chimeric methyltransferase. Control experiments confirmed that the methylation was dependent on the fusion of the Zinc finger and the methyltransferase domains and specific for the target region. The stable cell lines with methylated EpCAM promoter showed a 60-80% reduction of EpCAM expression as determined at mRNA and protein level and exhibited a significantly reduced cell proliferation. Our data indicate that targeted methylation of the EpCAM promoter could be an approach in the therapy of EpCAM overexpressing cancers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Neoplasm / genetics*
  • Antigens, Neoplasm / metabolism
  • Base Sequence
  • Cell Adhesion Molecules / genetics*
  • Cell Adhesion Molecules / metabolism
  • Cell Line, Tumor
  • Cell Proliferation
  • DNA Methylation*
  • Epithelial Cell Adhesion Molecule
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Gene Silencing
  • Humans
  • Molecular Sequence Data
  • Ovarian Neoplasms
  • Promoter Regions, Genetic*
  • Sequence Analysis, DNA

Substances

  • Antigens, Neoplasm
  • Cell Adhesion Molecules
  • EPCAM protein, human
  • Epithelial Cell Adhesion Molecule

Grants and funding

This work has been supported by the Sander Foundation and the DAAD (Deutscher Akademischer Austauschdienst). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.