Circular RNA-encoded oncogenic E-cadherin variant promotes glioblastoma tumorigenicity through activation of EGFR-STAT3 signalling

Nat Cell Biol. 2021 Mar;23(3):278-291. doi: 10.1038/s41556-021-00639-4. Epub 2021 Mar 4.

Abstract

Activated EGFR signalling drives tumorigenicity in 50% of glioblastoma (GBM). However, EGFR-targeting therapy has proven ineffective in treating patients with GBM, indicating that there is redundant EGFR activation. Circular RNAs are covalently closed RNA transcripts that are involved in various physiological and pathological processes. Herein, we report an additional activation mechanism of EGFR signalling in GBM by an undescribed secretory E-cadherin protein variant (C-E-Cad) encoded by a circular E-cadherin (circ-E-Cad) RNA through multiple-round open reading frame translation. C-E-Cad is overexpressed in GBM and promotes glioma stem cell tumorigenicity. C-E-Cad activates EGFR independent of EGF through association with the EGFR CR2 domain using a unique 14-amino-acid carboxy terminus, thereby maintaining glioma stem cell tumorigenicity. Notably, inhibition of C-E-Cad markedly enhances the antitumour activity of therapeutic anti-EGFR strategies in GBM. Our results uncover a critical role of C-E-Cad in stimulating EGFR signalling and provide a promising approach for treating EGFR-driven GBM.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD / genetics
  • Antigens, CD / metabolism*
  • Antineoplastic Agents / pharmacology
  • Brain Neoplasms / drug therapy
  • Brain Neoplasms / enzymology*
  • Brain Neoplasms / genetics
  • Brain Neoplasms / pathology
  • Cadherins / genetics
  • Cadherins / metabolism*
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • ErbB Receptors / antagonists & inhibitors
  • ErbB Receptors / genetics
  • ErbB Receptors / metabolism
  • Female
  • Gene Expression Regulation, Neoplastic
  • Glioblastoma / drug therapy
  • Glioblastoma / enzymology*
  • Glioblastoma / genetics
  • Glioblastoma / pathology
  • Humans
  • Mice, Nude
  • Neoplasm Invasiveness
  • RNA, Circular / genetics
  • RNA, Circular / metabolism*
  • STAT3 Transcription Factor / genetics
  • STAT3 Transcription Factor / metabolism*
  • Signal Transduction
  • Tumor Burden / drug effects
  • Xenograft Model Antitumor Assays

Substances

  • Antigens, CD
  • Antineoplastic Agents
  • CDH1 protein, human
  • Cadherins
  • RNA, Circular
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • EGFR protein, human
  • ErbB Receptors