Xin He

Glioma is known to induce local and systemic immunosuppression, which inhibits antitumor T cell responses. The galectin-9-Tim-3-pathway negatively regulates T cell pathways in the tumor immunosuppressive environment. The present study assessed the expression of Tim-3 and galectin-9 in glioma patients, and evaluated the association between the expression of Tim-3 and galectin-9 with clinical characteristics. The present study identified that Tim-3 expression was significantly increased in peripheral blood T cells of glioma patients compared with those of healthy controls, and was additionally increased on tumor-infiltrating T cells. The expression of Tim-3 on tumor-infiltrating T cells was associated with the World Health Organization (WHO) grade of glioma, but negatively correlated with the Karnofsky Performance Status score of the glioma patients. Immunohistochemical analysis revealed that the expression of galectin-9 in tumor tissues was associated with Tim-3 expression on tumor-infiltrating T cells and the WHO grade of glioma. These findings suggest that the galectin-9-Tim-3 pathway may be critical in the immunoevasion of glioma and may be a potent target for immunotherapy in glioma patients.

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.

Numerous studies have indicated that four interacting factors, including oxidative stress, mitochondrial alterations, calcium dyshomeostasis and inflammation, play crucial pathological roles in multiple major neurological diseases, including stroke, Alzheimer's disease (AD) and Parkinson's disease (PD). Increasing evidence has also indicated that NAD(+) plays important roles in not only mitochondrial functions and energy metabolism, but also calcium homeostasis and inflammation. The key NAD(+)-consuming enzyme--poly(ADP-ribose) polymerase-1 (PARP-1) and sirtuins--have also been shown to play important roles in cell death and aging, which are two key factors in the pathology of multiple major age-dependent neurological diseases: PARP-1 plays critical roles in both inflammation and oxidative stress-induced cell death; and sirtuins also mediate the process of aging, cell death and inflammation. Thus, it is conceivable that increasing evidence has suggested that NAD(+) metabolism and NAD(+)-dependent enzymes are promising targets for treating a number of neurological illnesses. For examples, the key NAD(+)-dependent enzymes SIRT1 and SIRT2 have been indicated to strongly affect the pathological changes of PD and AD; PARP-1 inhibition can profoundly reduce the brain injury in the animal models of multiple neurological diseases; and administration of either NAD(+) or nicotinamide can also decrease ischemic brain damage. Future studies are necessary to further investigate the roles of NAD+ metabolism and NAD⁺-dependent enzymes in neurological diseases, which may expose novel targets for treating the debilitating illnesses.