Bisphenol AF-induced endogenous transcription is mediated by ERα and ERK1/2 activation in human breast cancer cells

PLoS One. 2014 Apr 11;9(4):e94725. doi: 10.1371/journal.pone.0094725. eCollection 2014.

Abstract

Bisphenol AF (BPAF)-induced transcriptional activity has been evaluated by luciferase reporter assay. However, the molecular mechanism of BPAF-induced endogenous transcription in human breast cancer cells has not been fully elucidated. In the present study, we investigated the effect and mechanism of BPAF-induced endogenous transcription detected by real-time PCR in human breast cancer cells. We found that BPAF stimulated transcription of estrogen responsive genes, such as trefoil factor 1 (TFF1), growth regulation by estrogen in breast cancer 1 (GREB1) and cathepsin D (CTSD), through dose-dependent and time-dependent manners in T47D and MCF7 cells. Gene-silencing of ERα, ERβ and G protein-coupled estrogen receptor 1 (GPER) by small interfering RNA revealed that BPAF-induced endogenous transcription was dependent on ERα and GPER, implying both genomic and nongenomic pathways might be involved in the endogenous transcription induced by BPAF. ERα-mediated gene transcription was further confirmed by inhibition of ER activity using ICI 182780 in ERα-positive T47D and MCF7 cells as well as overexpression of ERα in ERα-negative MDA-MB-231 breast cancer cells. Moreover, we utilized Src tyrosine kinase inhibitor PP2 and two MEK inhibitors PD98059 and U0126 to elucidate the rapid nongenomic activation of Src/MEK/ERK1/2 cascade on endogenous transcription. Our data showed that BPAF-induced transcription could be significantly blocked by PP2, PD98059 and U0126, suggesting activation of ERK1/2 was also required to regulate endogenous transcription. Taken together, these results indicate that BPAF-induced endogenous transcription of estrogen responsive genes is mediated through both genomic and nongenomic pathways involving the ERα and ERK1/2 activation in human breast cancer cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzhydryl Compounds / pharmacology*
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / metabolism*
  • Cell Line, Tumor
  • Enzyme Activation
  • Estrogen Receptor alpha / metabolism*
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects*
  • Humans
  • Mitogen-Activated Protein Kinase 1 / metabolism*
  • Mitogen-Activated Protein Kinase 3 / metabolism*
  • Phenols / pharmacology*
  • Proto-Oncogene Proteins B-raf / metabolism
  • Receptors, Estrogen / metabolism
  • Receptors, G-Protein-Coupled / metabolism
  • Transcription, Genetic

Substances

  • Benzhydryl Compounds
  • Estrogen Receptor alpha
  • GPER1 protein, human
  • Phenols
  • Receptors, Estrogen
  • Receptors, G-Protein-Coupled
  • Proto-Oncogene Proteins B-raf
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • 4,4'-hexafluorisopropylidene diphenol

Grants and funding

This work was supported by National Natural Science Foundation of China (grant number 41273132 and 21207008) and the Beijing Municipal Senior Technical Training Plan for the Health System. URL of National Natural Science Foundation of China is http://www.nsfc.gov.cn/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.