Role of IL-6 in the invasiveness and prognosis of glioma.

IL-6 is a cytokine secreted by glioma cells and plays an important role in the tumor growth. However, the impact of IL-6 on the invasiveness and prognosis of glioma is still unclear. In this study, immunohistochemistry was performed to determine the expression of IL-6 in 86 glioma tissues, and ELISA to measure IL-6 in the serum and cerebrospinal fluid (CSF) of these patients. Results showed, as ccompared with normal controls, the IL-6 in the glioma, CSF and serumincreased remarkably, and increased with the elevation of glioma grade. In addition, IL-6 in the supernatant was also detectable in glioma cell lines U251, U87, A172 and T98G. Transwell invasion assay showed that the invasiveness of glioma U87 cells and U251 cells increased remarkably after exogenous IL-6 treatment. Survival analysis indicated higher IL-6 before surgery and significantly reduction in IL-6 after operation in the serum and CSF predicted a poor prognosis. Thus, we speculate that, the poor prognosis of glioma is related to the IL-6 autocrine in the glioma and the IL-6 induced tumor growth and invasion. IL-6 may serve as a therapeutic target for glioma patients and IL-6 in the CSF and serum of glioma may be used to predict the prognosis of these patients.