An EGF receptor inhibitor induces RAR-beta expression in breast and ovarian cancer cells

Biochem Biophys Res Commun. 2005 Apr 22;329(4):1253-9. doi: 10.1016/j.bbrc.2005.02.104.

Abstract

Inhibition of the epidermal growth factor (EGF)-receptor (EGFR) has become a promising anticancer treatment strategy. In addition, application of retinoids yields encouraging results for cancer prevention and therapy. Many tumors express no or low amounts of retinoic acid receptor-beta2 (RAR-beta2) due to epigenetic silencing via DNA hypermethylation. RAR-beta2 is the main mediator of the antiproliferative effect of retinoids. RAR-beta2 re-expression causes reversal of transformation, cell cycle arrest, and restoration of retinoid sensitivity. RAR-beta2 is thus a tumor suppressor. Western blotting, colorimetric in vitro cell proliferation assays, and reverse transcription-polymerase chain reaction demonstrated that the EGFR inhibitor PD153035 not only blocked activation of EGFR and inhibited cell growth, but also stimulated RAR-beta expression in MDA-MB-468 breast and OVCAR-3 ovarian carcinoma cells. Upregulation of RAR-beta by PD153035 was confirmed by real-time reverse transcription-polymerase chain reaction. In contrast, expression of other retinoid receptors and of estrogen receptor-alpha was not affected. PD153035-mediated re-induction of RAR-beta was associated with demethylation of the RAR-beta2 gene promoter P2 as demonstrated by methylation-specific polymerase chain reaction. These novel results on the ErbB/retinoid receptor cross-talk may be useful for designing future anticancer combination regimens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism*
  • Breast Neoplasms / pathology
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Enzyme Activation
  • ErbB Receptors / antagonists & inhibitors*
  • ErbB Receptors / metabolism
  • Female
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Methylation / drug effects
  • Ovarian Neoplasms / genetics
  • Ovarian Neoplasms / metabolism*
  • Ovarian Neoplasms / pathology
  • Promoter Regions, Genetic / genetics
  • Quinazolines / pharmacology*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Receptor, ErbB-2 / genetics
  • Receptor, ErbB-2 / metabolism
  • Receptors, Retinoic Acid / genetics
  • Receptors, Retinoic Acid / metabolism*

Substances

  • Quinazolines
  • RNA, Messenger
  • Receptors, Retinoic Acid
  • retinoic acid receptor beta
  • ErbB Receptors
  • Receptor, ErbB-2
  • 4-((3-bromophenyl)amino)-6,7-dimethoxyquinazoline