Epigenetic changes of EGFR have an important role in BRAF inhibitor-resistant cutaneous melanomas

J Invest Dermatol. 2015 Feb;135(2):532-541. doi: 10.1038/jid.2014.418. Epub 2014 Sep 22.

Abstract

BRAF mutations are frequent in cutaneous melanomas, and BRAF inhibitors (BRAFi) have shown remarkable clinical efficacy in BRAF mutant melanoma patients. However, acquired drug resistance can occur rapidly and tumor(s) often progresses thereafter. Various mechanisms of BRAFi resistance have recently been described; however, the mechanism of resistance remains controversial. In this study, we developed BRAFi-resistant melanoma cell lines and found that metastasis-related epithelial to mesenchymal transition properties of BRAFi-resistant cells were enhanced significantly. Upregulation of EGFR was observed in BRAFi-resistant cell lines and patient tumors because of demethylation of EGFR regulatory DNA elements. EGFR induced PI3K/AKT pathway activation in BRAFi-resistant cells through epigenetic regulation. Treatment of EGFR inhibitor was effective in BRAFi-resistant melanoma cell lines. The study demonstrates that EGFR epigenetic activation has important implications in BRAFi resistance in melanoma.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • DNA Methylation
  • Drug Resistance, Neoplasm
  • Epigenesis, Genetic*
  • Epithelial-Mesenchymal Transition
  • ErbB Receptors / genetics*
  • ErbB Receptors / physiology
  • Humans
  • Melanoma / drug therapy*
  • Melanoma / genetics
  • Melanoma / pathology
  • Phosphatidylinositol 3-Kinases / physiology
  • Proto-Oncogene Proteins B-raf / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-akt / physiology
  • Skin Neoplasms / drug therapy*
  • Skin Neoplasms / genetics
  • Skin Neoplasms / pathology

Substances

  • Phosphatidylinositol 3-Kinases
  • EGFR protein, human
  • ErbB Receptors
  • Proto-Oncogene Proteins B-raf
  • Proto-Oncogene Proteins c-akt

Associated data

  • SRA/SRP022029