An alkylphenol mix promotes seminoma derived cell proliferation through an ERalpha36-mediated mechanism

PLoS One. 2013 Apr 23;8(4):e61758. doi: 10.1371/journal.pone.0061758. Print 2013.

Abstract

Long chain alkylphenols are man-made compounds still present in industrial and agricultural processes. Their main use is domestic and they are widespread in household products, cleansers and cosmetics, leading to a global environmental and human contamination. These molecules are known to exert estrogen-like activities through binding to classical estrogen receptors. In vitro, they can also interact with the G-protein coupled estrogen receptor. Testicular germ cell tumor etiology and progression are proposed to be stimulated by lifelong estrogeno-mimetic exposure. We studied the transduction signaling pathways through which an alkyphenol mixture triggers testicular cancer cell proliferation in vitro and in vivo. Proliferation assays were monitored after exposure to a realistic mixture of 4-tert-octylphenol and 4-nonylphenol of either TCam-2 seminoma derived cells, NT2/D1 embryonal carcinoma cells or testis tumor in xenografted nude mice. Specific pharmacological inhibitors and gene-silencing strategies were used in TCam-2 cells in order to demonstrate that the alkylphenol mix triggers CREB-phosphorylation through a rapid, ERα36-PI3kinase non genomic pathway. Microarray analysis of the mixture target genes revealed that this pathway can modulate the expression of the DNA-methyltransferase-3 (Dnmt3) gene family which is involved in DNA methylation control. Our results highlight a key role for ERα36 in alkylphenol non genomic signaling in testicular germ cell tumors. Hence, ERα36-dependent control of the epigenetic status opens the way for the understanding of the link between endocrine disruptor exposure and the burden of hormone sensitive cancers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Androstadienes / pharmacology
  • Animals
  • Carcinogens, Environmental / pharmacology*
  • Carcinoma / genetics*
  • Carcinoma / metabolism
  • Carcinoma / pathology
  • Cell Proliferation / drug effects
  • Cyclic AMP Response Element-Binding Protein / genetics
  • Cyclic AMP Response Element-Binding Protein / metabolism
  • DNA (Cytosine-5-)-Methyltransferases / genetics
  • DNA (Cytosine-5-)-Methyltransferases / metabolism
  • DNA Methyltransferase 3A
  • Epigenesis, Genetic / drug effects
  • Estrogen Receptor alpha / genetics*
  • Estrogen Receptor alpha / metabolism
  • Gene Expression Regulation, Neoplastic / drug effects
  • Male
  • Mice
  • Mice, Nude
  • Neoplasm Transplantation
  • Phenols / pharmacology*
  • Phosphatidylinositol 3-Kinases / genetics
  • Phosphatidylinositol 3-Kinases / metabolism
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Seminoma / genetics*
  • Seminoma / metabolism
  • Seminoma / pathology
  • Signal Transduction
  • Testicular Neoplasms / genetics*
  • Testicular Neoplasms / metabolism
  • Testicular Neoplasms / pathology
  • Wortmannin

Substances

  • Androstadienes
  • Carcinogens, Environmental
  • Creb1 protein, mouse
  • Cyclic AMP Response Element-Binding Protein
  • DNMT3A protein, human
  • Estrogen Receptor alpha
  • Phenols
  • Protein Isoforms
  • DNA (Cytosine-5-)-Methyltransferases
  • DNA Methyltransferase 3A
  • 4-nonylphenol
  • 4-tert-octylphenol
  • Wortmannin

Grants and funding

This work was supported by ANSES (APR EST 08-09). HA is the recipient of a Syrian Government fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.