miR-219-5p inhibits receptor tyrosine kinase pathway by targeting EGFR in glioblastoma

PLoS One. 2013 May 17;8(5):e63164. doi: 10.1371/journal.pone.0063164. Print 2013.

Abstract

Glioblastoma is one of the common types of primary brain tumors with a median survival of 12-15 months. The receptor tyrosine kinase (RTK) pathway is known to be deregulated in 88% of the patients with glioblastoma. 45% of GBM patients show amplifications and activating mutations in EGFR gene leading to the upregulation of the pathway. In the present study, we demonstrate that a brain specific miRNA, miR-219-5p, repressed EGFR by directly binding to its 3'-UTR. The expression of miR-219-5p was downregulated in glioblastoma and the overexpression of miR-219-5p in glioma cell lines inhibited the proliferation, anchorage independent growth and migration. In addition, miR-219-5p inhibited MAPK and PI3K pathways in glioma cell lines in concordance with its ability to target EGFR. The inhibitory effect of miR-219-5p on MAPK and PI3K pathways and glioma cell migration could be rescued by the overexpression of wild type EGFR and vIII mutant of EGFR (both lacking 3'-UTR and thus being insensitive to miR-219-5p) suggesting that the inhibitory effects of miR-219-5p were indeed because of its ability to target EGFR. We also found significant negative correlation between miR-219-5p levels and total as well as phosphorylated forms of EGFR in glioblastoma patient samples. This indicated that the downregulation of miR-219-5p in glioblastoma patients contribute to the increased activity of the RTK pathway by the upregulation of EGFR. Thus, we have identified and characterized miR-219-5p as the RTK regulating novel tumor suppressor miRNA in glioblastoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions / genetics
  • Blotting, Western
  • Cell Line, Tumor
  • Colony-Forming Units Assay
  • DNA Primers / genetics
  • ErbB Receptors / metabolism*
  • Glioblastoma / metabolism*
  • Humans
  • MicroRNAs / metabolism*
  • Microarray Analysis
  • Mutagenesis, Site-Directed
  • Real-Time Polymerase Chain Reaction
  • Receptor Protein-Tyrosine Kinases / antagonists & inhibitors*
  • Receptor Protein-Tyrosine Kinases / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / physiology*

Substances

  • 3' Untranslated Regions
  • DNA Primers
  • MIRN219 microRNA, human
  • MicroRNAs
  • EGFR protein, human
  • ErbB Receptors
  • Receptor Protein-Tyrosine Kinases

Grants and funding

The study is funded by Department of Biotechnology, Government of India. SAR gratefully acknowledges Senior Research Fellowship from CSIR. KS is a J. C. Bose Fellow of the Department of Science and Technology. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.