Induction of interleukin-6 by irradiation and its role in epithelial mesenchymal transition and radioresistance of nasopharyngeal carcinoma cells

Head Neck. 2021 Mar;43(3):757-767. doi: 10.1002/hed.26531. Epub 2020 Nov 5.

Abstract

Background: Epithelial mesenchymal transition (EMT) participates in the radioresistance of cancer cells. In this study, we evaluated whether interleukin-6 (IL-6) regulates EMT and subsequent radioresistance in nasopharyngeal carcinoma (NPC) cells.

Methods: Western blot was used to analyze the expression of proteins. Immunofluorescent assay was performed to detect the position and content of specific proteins. Colony formation assay was applied to measure the proliferation ability of NPC cells. Flow cytometry was adopted to measure cell apoptosis.

Results: NPC cells seen with typical morphological transition and unique proteins change of EMT when exposed to irradiation. IL-6 and its downstream signal molecules elevated in irradiated cells. Blocking IL-6 with anti-IL-6 receptor antibody hampered EMT and radioresistance. Cell radiosensitivity and apoptosis rates in irradiated NPC cells declined significantly upon IL-6 stimulation.

Conclusion: Irradiation could induce EMT and activate IL-6 signaling in NPC cell lines. Blocking IL-6 was able to inhibit EMT and cellular radioresistance.

Keywords: epithelial mesenchymal transition; interleukin-6; nasopharyngeal carcinoma; radioresistance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Epithelial-Mesenchymal Transition*
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Interleukin-6
  • Nasopharyngeal Carcinoma / genetics
  • Nasopharyngeal Carcinoma / radiotherapy
  • Nasopharyngeal Neoplasms* / genetics
  • Nasopharyngeal Neoplasms* / radiotherapy
  • Radiation Tolerance

Substances

  • Interleukin-6