Identification of a novel role of IL-13Rα2 in human Glioblastoma multiforme: interleukin-13 mediates signal transduction through AP-1 pathway

Rukmini Bhardwaj; Akiko Suzuki; Pamela Leland; Bharat H Joshi; Raj K Puri

doi:10.1186/s12967-018-1746-6

Identification of a novel role of IL-13Rα2 in human Glioblastoma multiforme: interleukin-13 mediates signal transduction through AP-1 pathway

J Transl Med. 2018 Dec 20;16(1):369. doi: 10.1186/s12967-018-1746-6.

Authors

Rukmini Bhardwaj¹, Akiko Suzuki¹, Pamela Leland¹, Bharat H Joshi¹, Raj K Puri²

Affiliations

¹ Division of Cellular and Gene Therapies (DCGT) Office of Tissues and Advanced Therapies (OTAT), Center for Biologics Evaluation and Research (CBER), Food and Drug Administration (FDA), Silver Spring, MD, USA.
² Division of Cellular and Gene Therapies (DCGT) Office of Tissues and Advanced Therapies (OTAT), Center for Biologics Evaluation and Research (CBER), Food and Drug Administration (FDA), Silver Spring, MD, USA. raj.puri@fda.hhs.gov.

Abstract

Background: Previously, we have demonstrated that Interleukin 13 receptor alpha 2 (IL-13Rα2) is overexpressed in approximate 78% Glioblastoma multiforme (GBM) samples. We have also demonstrated that IL-13Rα2 can serve as a target for cancer immunotherapy in several pre-clinical and clinical studies. However, the significance of overexpression of IL-13Rα2 in GBM and astrocytoma and signaling through these receptors is not known. IL-13 can signal through IL-13R via JAK/STAT and AP-1 pathways in certain cell lines including some tumor cell lines. Herein, we have investigated a role of IL-13/IL-13Rα2 axis in signaling through AP-1 transcription factors in human glioma samples in situ.

Methods: We examined the activation of AP-1 family of transcription factors (c-Jun, Fra-1, Jun-D, c-Fos, and Jun-B) after treating U251, A172 (IL-13Rα2 +ve) and T98G (IL-13Rα2 -ve) glioma cell lines with IL-13 by RT-qPCR, and immunocytochemistry (ICC). We also performed colorimetric ELISA based assay to determine AP-1 transcription factor activation in glioma cell lines. Furthermore, we examined the expression of AP-1 transcription factors in situ in GBM and astrocytoma specimens by multiplex-immunohistochemistry (IHC). Student t test and ANOVA were used for statistical analysis of the results.

Results: We have demonstrated up-regulation of two AP-1 transcription factors (c-Jun and Fra-1) at mRNA and protein levels upon treatment with IL-13 in IL-13Rα2 positive but not in IL-13Rα2 negative glioma cell lines. Both transcription factors were also overexpressed in patient derived GBM specimens, however, in contrast to GBM cell lines, c-Fos is also overexpressed in patient derived specimens. Astrocytoma specimens showed lesser extent of immunostaining for IL-13Rα2 and three AP-1 factors compared to GBM specimens. By transcription factor activation assay, we demonstrated that AP-1 transcription factors (C-Jun and Fra-1) were activated upon treatment of IL-13Rα2 + GBM cell lines but not IL-13Rα2 - GBM cell line with IL-13. Our results demonstrate functional activity of AP-1 transcription factor in GBM cell lines in response to IL-13.

Conclusions: These results indicate that IL-13/IL-13Rα2 axis can mediate signal transduction in situ via AP-1 pathway in GBM and astrocytoma and may serve as a new target for GBM immunotherapy.

Keywords: AP-1; Glioblastoma; IL-13; IL-13Rα2; Transcription factors.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Astrocytoma / pathology
Cell Line, Tumor
Female
Gene Expression Regulation, Neoplastic
Glioblastoma / genetics
Glioblastoma / metabolism*
Glioblastoma / pathology
Humans
Interleukin-13 / metabolism*
Interleukin-13 Receptor alpha2 Subunit / metabolism*
Male
Middle Aged
Models, Biological
RNA, Messenger / genetics
RNA, Messenger / metabolism
Signal Transduction*
Transcription Factor AP-1 / metabolism*

Substances

Interleukin-13
Interleukin-13 Receptor alpha2 Subunit
RNA, Messenger
Transcription Factor AP-1