NFAT1-regulated IL6 signalling contributes to aggressive phenotypes of glioma

Abstract

BackgroundWe previously demonstrated that the local immune status correlated with the glioma prognosis. Interleukin-6 (IL6) was identified as an important local immune-related risk marker related to unfavourable prognosis. In this study, we further investigated the role and regulation of IL6 signalling in glioma.MethodsThe expression and prognostic value of IL6 and the IL6 receptor (IL6R) were explored in The Cancer Genome Atlas (TCGA) and REMBRANDT databases and clinical samples. Functional effects of genetic knockdown and overexpression of IL6R or IL6 stimulation were examined in vitro and in tumours in vivo. The effects of the nuclear factor of activated T cells-1 (NFAT1) on the promoter activities of IL6R and IL6 were also examined.ResultsHigh IL6- and IL6R-expression were significantly associated with mesenchymal subtype and IDH-wildtype gliomas, and were predictors of poor survival. Knockdown of IL6R decreased cell proliferation, invasion and neurosphere formation in vitro, and inhibited tumorigenesis in vivo. IL6R overexpression or IL6 stimulation enhanced the invasion and growth of glioma cells. TCGA database searching revealed that IL6- and IL6R-expression were correlated with that of NFAT1. In glioma cells, NFAT1 enhanced the promoter activities of IL6R and IL6, and upregulated the expression of both IL6R and IL6.ConclusionNFAT1-regulated IL6 signalling contributes to aggressive phenotypes of gliomas, emphasizing the role of immunomodulatory factors in glioma malignant progression.Electronic supplementary materialThe online version of this article (10.1186/s12964-017-0210-1) contains supplementary material, which is available to authorized users.

Astrocytes, the rising stars of the glioblastoma microenvironment

“…In a similar way, reactive astrocytes have been observed to secrete IL‐6, a protein able to enhance primary GBM cell invasion in vitro (Chen et al, ; Li et al, ). Indeed, GBM development, aggressiveness, and poor prognosis have been linked to the high expression of IL‐6 (Jiang, Han, Cheng, Wang, & Wu, ; Tchirkov et al, ). Thus, Jiang et al ()) recently observed that the expression of both IL‐6 and IL‐6‐R was directly correlated to the highly aggressive mesenchymal GBM subtype and poor survival.…”

“…Indeed, GBM development, aggressiveness, and poor prognosis have been linked to the high expression of IL‐6 (Jiang, Han, Cheng, Wang, & Wu, ; Tchirkov et al, ). Thus, Jiang et al ()) recently observed that the expression of both IL‐6 and IL‐6‐R was directly correlated to the highly aggressive mesenchymal GBM subtype and poor survival. In the same way, Li et al ()) showed that IL‐6 promotes the in vitro invasion of U87 GBM cells by upregulating the expression and secretion of MMP2 and fascin‐1 , an actin‐bundling protein involved in the formation of cellular protrusions enabling cell migration.…”

“…Based on this article, TAAS‐produced IL‐6 appears to be at the crossroads of multiple TAAs' effects on GBM development, including promoting proliferation and invasion but also modulating immune response to tumor progression (Chen, Xia, et al, ; Jiang et al, ; Lee et al, ; Seike et al, ; Yin et al, ; Zamanian et al, ). This key cytokine might thus be considered as a target for new therapies but also as a specific biomarker since its expression has been observed as mostly associated with mesenchymal GBM (Jiang et al, ). Nevertheless, most of the work that has been done on TAAs‐IL‐6 was in vitro, suggesting that further in vivo studies will be needed to strengthen its clinical relevance.…”

NFAT1-Mediated Regulation of NDEL1 Promotes Growth and Invasion of Glioma Stem-like Cells

“…The cancer stem cell nature of isolated GSCs was confirmed by functional assays of self-renewal and tumor formation. The expression of stem cell markers (CD15, CD133, CD44, and Nestin) was detected by flow cytometry or immunofluorescence and the multi-lineage differentiation capacity of GSCs was examined by immunofluorescence (17). In some experiments, GSCs were cultured in DMEM/F12 supplemented with 10% FBS for differentiation.…”

“…Immunofluorescence staining was performed as previously described (14,17). Antibodies against CD44 (1:500; ab157107), CD133 (1:100; ab19898), Nestin (1:250; ab6320, ab134017), GFAP (1:1,000; ab7260), b III tubulin (1:1,000; ab78078), NFAT1 (1:200; ab2722), and NDEL1 (1:500; ab25959) were used to detect the expression and intracellular localization of these proteins.…”