Identification of a novel role of IL-13R2 in human Glioblastoma multiforme: interleukin-13 mediates signal transduction through AP-1 pathway
Identification of a novel role of IL-13R2 in human Glioblastoma multiforme: interleukin-13 mediates signal transduction through AP-1 pathway
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DOI：
10.1186/s12967-018-1746-6
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发表时间：
2018-12-20
影响因子：
7.4
通讯作者：
Puri, Raj K.
中科院分区：
文献类型：
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作者：
Bhardwaj, Rukmini;Suzuki, Akiko;Puri, Raj K.
背景我们已经证实，大约78%的多形性胶质母细胞瘤（GBM）中存在白细胞介素13受体α 2（IL-13 R2）的过表达。我们还证明了IL-13 R2可以在几项临床前和临床研究中作为癌症免疫治疗的靶点。然而，GBM和星形细胞瘤中IL-13 R2过表达的意义以及通过这些受体的信号传导尚不清楚。IL-13可以通过IL-13 R经由JAK/STAT和AP-1途径在某些细胞系（包括一些肿瘤细胞系）中进行信号传导。在此，我们研究了IL-13/IL-13 R2轴在人脑胶质瘤原位标本中通过AP-1转录因子进行信号传导的作用。通过RT-qPCR和免疫细胞化学（ICC）检测在用IL-13处理U251、A172（IL-13 R2 +ve）和T98 G（IL-13 R2-ve）胶质瘤细胞系之后的细胞（c-Jun、Fra-1、Jun-D、c-Fos和Jun-B）。我们还进行了基于比色ELISA的测定来确定神经胶质瘤细胞系中AP-1转录因子的活化。此外，我们研究了AP-1转录因子的表达在GBM和星形细胞瘤标本原位多重免疫组织化学（IHC）。Student t检验和方差分析用于统计分析的结果。ResultsWe已经证明上调两个AP-1转录因子（c-Jun和Fra-1）在mRNA和蛋白质水平与IL-13处理后，在IL-13 R2阳性，但不是在IL-13 R2阴性胶质瘤细胞系。两种转录因子在患者来源的GBM标本中也过表达，然而，与GBM细胞系相反，c-Fos在患者来源的标本中也过表达。与GBM标本相比，星形细胞瘤标本显示IL-13 R2和三种AP-1因子的免疫染色程度较低。通过转录因子激活试验，我们证明了AP-1转录因子（C-Jun和Fra-1）在IL-13处理IL-13 R2 + GBM细胞系而不是IL-13 R2-GBM细胞系时被激活。结论IL-13/IL-13 R2轴在GBM和星形细胞瘤中可通过AP-1途径原位介导信号转导，可能成为GBM免疫治疗的新靶点。
BackgroundPreviously, we have demonstrated that Interleukin 13 receptor alpha 2 (IL-13R2) is overexpressed in approximate 78% Glioblastoma multiforme (GBM) samples. We have also demonstrated that IL-13R2 can serve as a target for cancer immunotherapy in several pre-clinical and clinical studies. However, the significance of overexpression of IL-13R2 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-13R2 axis in signaling through AP-1 transcription factors in human glioma samples in situ.MethodsWe 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-13R2 +ve) and T98G (IL-13R2 -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.ResultsWe 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-13R2 positive but not in IL-13R2 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-13R2 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-13R2+GBM cell lines but not IL-13R2-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.ConclusionsThese results indicate that IL-13/IL-13R2 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.