The role of HGF-MET pathway and CCDC66 cirRNA expression in EGFR resistance and epithelial-to-mesenchymal transition of lung adenocarcinoma cells

J Hematol Oncol. 2018 May 31;11(1):74. doi: 10.1186/s13045-018-0557-9.

Abstract

Background: Epithelial-to-mesenchymal transition (EMT) has, in recent years, emerged as an important tumor cell behavior associated with high metastatic potential and drug resistance. Interestingly, protein SUMOylation and hepatocyte growth factor could respectively reduce the effect of small molecule inhibitors on tyrosine kinase activity of mutated epidermal growth factor receptor of lung adenocarcinomas (LADC). The actual mechanism is yet to be resolved.

Methods: Immunohistochemistry was used to stain proteins in LADC specimens. Protein expression was confirmed by Western blotting. In vitro, expression of proteins was determined by Western blotting and immunocytochemistry. Levels of circular RNA were determined by reverse transcription-polymerase chain reaction.

Results: SAE2 and cirRNA CCDC66 were highly expressed in LADC. Expression of SAE2 was mainly regulated by EGFR; however, expression of cirRNA CCDC66 was positively regulated by FAK and c-Met but negatively modulated by nAchR7α. EGFR-resistant H1975 also highly expressed cirRNA CCDC66. Immediate response of hypoxia increased phosphorylated c-Met, SAE2, and epithelial-to-mesenchymal transition. Either activation of FAK or silencing of nAchR7α increased cirRNA CCDC66.

Conclusions: HGF/c-Met regulates expression of SAE2 and cirRNA CCDC66 to increase EMT and drug resistance of LADC cells. Multimodality drugs concurrently aiming at these targets would probably provide more benefits for cancer patients.

Keywords: CCDC66; EGFR; EMT; HGF; SAE2; SUMOylation; c-MET; cirRNA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / pathology
  • Cell Line
  • Cell-Free Nucleic Acids / analysis
  • Drug Resistance / drug effects
  • Epithelial-Mesenchymal Transition / drug effects
  • ErbB Receptors / pharmacology
  • Eye Proteins / genetics*
  • Gene Expression / drug effects
  • Hepatocyte Growth Factor / metabolism*
  • Humans
  • Lung Neoplasms / pathology*
  • Metabolic Networks and Pathways
  • Proto-Oncogene Proteins c-met / metabolism*
  • Ubiquitin-Activating Enzymes / metabolism

Substances

  • CCDC66 protein, human
  • Cell-Free Nucleic Acids
  • Eye Proteins
  • HGF protein, human
  • UBA2 protein, human
  • Hepatocyte Growth Factor
  • EGFR protein, human
  • ErbB Receptors
  • MET protein, human
  • Proto-Oncogene Proteins c-met
  • Ubiquitin-Activating Enzymes