IL22/IL-22R pathway induces cell survival in human glioblastoma cells

PLoS One. 2015 Mar 20;10(3):e0119872. doi: 10.1371/journal.pone.0119872. eCollection 2015.

Abstract

Interleukin-22 (IL-22) is a member of the IL-10 cytokine family that binds to a heterodimeric receptor consisting of IL-22 receptor 1 (IL-22R1) and IL-10R2. IL-22R expression was initially characterized on epithelial cells, and plays an essential role in a number of inflammatory diseases. Recently, a functional receptor was detected on cancer cells such as hepatocarcinoma and lung carcinoma, but its presence was not reported in glioblastoma (GBM). Two GBM cell lines and 10 primary cell lines established from patients undergoing surgery for malignant GBM were used to investigate the expression of IL-22 and IL-22R by using quantitative RT-PCR, western blotting and confocal microscopy studies. The role of IL-22 in proliferation and survival of GBM cell lines was investigated in vitro by BrdU and ELISA cell death assays. We report herein that the two subunits of the IL-22R complex are expressed on human GBM cells. Their activation, depending on exogenous IL-22, induced antiapoptotic effect and cell proliferation. IL-22 treatment of GBM cells resulted in increased levels of phosphorylated Akt, STAT3 signaling protein and its downstream antiapoptotic protein Bcl-xL and decreased level of phosphorylated ERK1/2. In addition, IL-22R subunits were expressed in all the 10 tested primary cell lines established from GBM tumors. Our results showed that IL-22R is expressed on GBM established and primary cell lines. Depending on STAT3, ERK1/2 and PI3K/Akt pathways, IL-22 induced GBM cell survival. These data are consistent with a potential role of IL-22R in tumorigenesis of GBM. Since endogenous IL-22 was not detected in all studied GBM cells, we hypothesize that IL-22R could be activated by immune microenvironmental IL-22 producing cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Cell Proliferation
  • Cell Survival / genetics
  • Gene Expression
  • Glioblastoma / genetics
  • Glioblastoma / metabolism*
  • Humans
  • Interleukin-10 Receptor beta Subunit / genetics
  • Interleukin-10 Receptor beta Subunit / metabolism
  • Interleukin-22
  • Interleukins / genetics
  • Interleukins / metabolism*
  • MAP Kinase Signaling System
  • Neoplastic Stem Cells
  • Phosphorylation
  • Proto-Oncogene Proteins c-akt / metabolism
  • Receptors, Interleukin / genetics
  • Receptors, Interleukin / metabolism*
  • STAT3 Transcription Factor / metabolism
  • Signal Transduction*

Substances

  • IL10RB protein, human
  • Interleukin-10 Receptor beta Subunit
  • Interleukins
  • Receptors, Interleukin
  • STAT3 Transcription Factor
  • interleukin-22 receptor
  • Proto-Oncogene Proteins c-akt

Grants and funding

This work was supported by grants from the Pôle de Recherche et d’Enseignement Supérieur (PRES) Limousin Poitou-Charentes and the Conseil Régional du Limousin; MOJ JCL. BIOalternatives provided support in the form of salaries for authors [FXB], but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of this author are articulated in the ‘author contributions’ section.