Epigenetic silencing of EYA2 in pancreatic adenocarcinomas promotes tumor growth

Oncotarget. 2014 May 15;5(9):2575-87. doi: 10.18632/oncotarget.1842.

Abstract

To identify potentially important genes dysregulated in pancreatic cancer, we analyzed genome-wide transcriptional analysis of pancreatic cancers and normal pancreatic duct samples and identified the transcriptional coactivator, EYA2 (Drosophila Eyes Absent Homologue-2) as silenced in the majority of pancreatic cancers. We investigated the role of epigenetic mechanisms of EYA2 gene silencing in pancreatic cancers, performed in vitro and in vivo proliferation and migration assays to assess the effect of EYA2 silencing on tumor cell growth and metastasis formation, and expression analysis to identify genes transcriptionally regulated by EYA2. We found loss of tumoral Eya2 expression in 63% of pancreatic cancers (120/189 cases). Silencing of EYA2 expression in pancreatic cancer cell lines correlated with promoter methylation and histone deacetylation and was reversible with DNA methyltransferase and HDAC inhibitors. EYA2 knockdown in pancreatic cancer cell lines increased cell proliferation. Compared to parental pancreatic cancer cells, pancreatic cancers stably-expressing EYA2 grew more slowly and had fewer metastases in orthotopic models. The transcriptional changes after stable expression of EYA2 in pancreatic cancer cells included induction of genes in the TGFbeta pathway. Epigenetic silencing of EYA2 is a common event in pancreatic cancers and stable expression EYA2 limits the growth and metastases of pancreatic adenocarcinoma.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenocarcinoma / genetics
  • Adenocarcinoma / metabolism
  • Adenocarcinoma / secondary*
  • Animals
  • Base Sequence
  • Blotting, Western
  • Cell Cycle
  • Cell Movement
  • Cell Proliferation*
  • Chromatin Immunoprecipitation
  • DNA Methylation
  • Epigenesis, Genetic*
  • Flow Cytometry
  • Gene Expression Regulation, Neoplastic*
  • Gene Silencing*
  • Humans
  • Immunoenzyme Techniques
  • Immunoprecipitation
  • Intracellular Signaling Peptides and Proteins / antagonists & inhibitors
  • Intracellular Signaling Peptides and Proteins / genetics*
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Male
  • Mice
  • Mice, Nude
  • Molecular Sequence Data
  • Neoplasm Metastasis
  • Nuclear Proteins / antagonists & inhibitors
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism
  • Pancreas / metabolism
  • Pancreatic Neoplasms / genetics
  • Pancreatic Neoplasms / metabolism
  • Pancreatic Neoplasms / pathology*
  • Promoter Regions, Genetic / genetics
  • Protein Tyrosine Phosphatases / antagonists & inhibitors
  • Protein Tyrosine Phosphatases / genetics*
  • Protein Tyrosine Phosphatases / metabolism
  • RNA, Messenger / genetics
  • RNA, Small Interfering / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tumor Cells, Cultured
  • Xenograft Model Antitumor Assays

Substances

  • Intracellular Signaling Peptides and Proteins
  • Nuclear Proteins
  • RNA, Messenger
  • RNA, Small Interfering
  • EYA2 protein, human
  • Protein Tyrosine Phosphatases