This study demonstrates that IL-6 secretion attenuates SC and IC glioma growth and SC rejection of IL-6 secreting T9.F cells induces long-term glioma immunity which is effective in the brain.
This was demonstrated using the argininocalix[4]arene 1 in miRNA therapeutic approaches performed on three well-described experimental model systems: (1) the induction of apoptosis by antimiR-221 in glioma U251 cells; (2) the induction of apoptosis by premiR-124 in U251 cells; and (3) the inhibition of pro-inflammatory IL-8 and IL-6 genes in cystic fibrosis IB3-1 cells.
To characterize the expression of IL-6 in the human glioma microenvironment, we investigated surgically excised human gliomas, human glioblastoma xenografts, and human glioblastoma cell lines using the reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and enzyme-linked immunosorbent assay (ELISA).
Together, our data indicate that IL6 signaling contributes to glioma malignancy through the promotion of GSC growth and survival, and that targeting IL6 may offer benefit for glioma patients.
Upon γ-irradiation of glioma cells, IκBζ expression is enhanced, and subsequently serves as a transcriptional activator of the tumor promoting cytokines interleukin (IL-6), IL-8 and chemokine (C-X-C motif) ligand 1 (CXCL1) that are known to be involved in glioma associated inflammatory processes.
Using gene array analysis of RTVP-1 silenced glioma cells we identified IL-6 as a mediator of RTVP-1 effects on the mesenchymal transformation and migration of GSCs, therefore acting in a positive feedback loop by upregulating RTVP-1 expression via the STAT3 pathway.
We examined the concentration of CSF IL-6 using 75 CSF samples of glioma (54 glioblastomas (GBMs) and 21 other grades of gliomas) and analyzed the association CSF IL-6 with infiltration levels of tumor-associated macrophages (TAMs) and prognosis.
We found that various GBM tumor-upregulated genes such as IL6, IL8 and CCL2 are also actively expressed in glioma cell lines, playing differential and cooperative roles in promoting proliferation, invasion, angiogenesis and macrophage polarization in vitro.
We next discovered that GRK5 knockdown inhibits the nuclear factor kappa B (NF-κB) pathway, thus resulting in downregulation of key downstream secretory products CCL2, IL-6 and IL-8 in glioma cell conditioned medium (CM).
We used the estimated odds ratio of glioma associated with each of the genetically defined traits to infer evidence for a causal relationship with the following exposures: lifestyle and dietary factors (height, plasma IGF-1, blood carnitine, blood methionine, blood selenium, blood zinc, circulating adiponectin, circulating carotenoids, iron status, serum calcium, vitamin [A1, B12, B6, E and 25-hydroxyvitamin D], fatty acids levels [mono-unsaturated, omega-3 and omega-6] and circulating fetuin-A); cardiometabolic factors (birth weight, HDL cholesterol, LDL cholesterol, total cholesterol, total triglycerides, basal metabolic rate, body fat percentage, body mass index, fasting glucose, fasting proinsulin, HbA1C levels, diastolic and systolic blood pressure, waist circumference, waist-to-hip ratio) were included; inflammatory factors (C-reactive protein (CRP), plasma IL-6 sRa and serum IgE).