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Objective: To assess oxidant and antioxidant status in patients with common brain tumors; namely meningiomas, low-grade gliomas (LGG) and high-grade gliomas (HGG) and to compare with normal brain tissues., Patients and Methods: Almost nine biomarkers were measured in 59 brain tumors obtained during surgery and 15 normal brain tissues that were collected during autopsy. Results were compared between two groups., Results: In general, protein oxidation and lipid peroxidation increased while antioxidant capacity decreased significantly in tumors compared to the controls (p<0.05) and higher the grade of the tumor, higher the levels of oxidation and lower the anti-oxidation., Conclusions: Reactive oxygen species may play a crucial role in the pathogenesis of these common brain tumors. As the processes at the molecular level understood, targeted-treatment adjunct to surgical removal will be possible to cope with these devastating brain tumors., (Copyright © 2017. Published by Elsevier B.V.)

Objective. Endocan has been shown to be a marker for several cancers and may show degree of malignancy. The aim of this study is to assess tissue levels of endocan in common brain tumors, namely, meningiomas, low-grade gliomas (LGGs), and high-grade gliomas (HGGs). Patients and Methods. Endocan was assayed by commercially available enzyme linked immunosorbent assay (ELISA) kits in a total of 50 brain tumors (20 meningiomas, 19 LGGs, and 20 HGGs) and 15 controls. The results were compared to control brain tissues. Results. Each tumor group showed significant higher levels of endocan compared to controls (p < 0.05). In addition, endocan levels showed steady increase from the least (meningiomas) to the most (HGGs) malignant tumors and positive correlation was noted between the degree of malignancy and endocan level (p = 0.0001). Conclusion. Endocan, a vital molecule for angiogenesis, is expressed in common brain tumors and results suggest that endocan could be a marker for malignancy.

Objective: The aim of this study was to assess plasma and/or tissue levels of adhesion and apoptotic molecules, cytokines, nitric oxide metabolites, levels of lipid peroxidation, myeloperoxidase and superoxide dismutase in patients with glioblastoma multiforme and controls., Methods: All the molecules were evaluated in 25 tumors and 30 controls: 15 were normal healthy subjects for plasma and 15 were normal brain tissues that were collected during autopsy. Commercially available kits for measurements were used., Results: Superoxide dismutase was significantly lower in tumors, while all other molecules were significantly elevated compared to the controls (p=0.0001). Superoxide dismutase negatively correlated with plasma interleukin-1beta (p=0.04) and plasma Fas (p=0.016). Plasma intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 correlated positively with plasma 3-nitrotyrosine (p=0.019) and nitrite/nitrate (p=0.019), respectively. Furthermore, plasma interleukin-1beta also positively correlated with plasma nitrite/nitrate (p=0.003)., Discussion: These results suggest that there is a complex relationship between pro- and anti-apoptotic molecules in glioblastoma multiforme pathogenesis. Thus, targeting multiple pathways with advanced chemotherapeutic agents or radiotheraupetic regimens following total resections might be helpful in patients with glioblastoma multiforme since preventing a single pathway does not seem to be reasonable.

Objectives: Elevated levels of lipid peroxidation and changes in the concentration of enzymatic and non-enzymatic antioxidant systems have been reported in various cancers, but there are very few reports available of lipid peroxidation due to oxidative stress in patients with intracranial neoplasms. The purpose of this study was to assess alterations in lipid peroxidation and antioxidant status in different types of tumors and to compare the results with their relative peritumoral tissues and compare the oxidative status in different grades of tumors., Patients and Methods: We investigated the extent of oxidative stress and the levels of antioxidants in 16 astrocytomas and 38 other different types intracranial tumors comparing the results with their corresponding peritumoral tissues and comparing the levels in between low-grade and high-grade tumors. The extent of lipid peroxidation as evidenced by the formation of thiobarbituric acid-reacting substances (TBARS), as well as the status of the antioxidant systems such as superoxide dismutase (SOD), glutathione reductase (GR) and reduced glutathione (GSH) in tumor tissues and adjacent peritumoral tissues was estimated. The tumoral tissues were also compared as to their degrees of malignancy., Results: According to our results lipid peroxidation in brain tumor tissues was enhanced compared to the corresponding adjacent peritumoral tissues. This was accompanied by a significant tumoral decrease in both enzymatic and non-enzymatic antioxidants. The low levels of antioxidants in tumor tissues, might be related to an increased use of antioxidant systems to scavenge lipid peroxides. Also a striking elevation in TBARS levels, and decrease in SOD activity and GSH levels were seen in high-grade tumors when compared with low grades., Conclusion: These findings emphasize a consistent difference in the level of antioxidants between the tumoral sample and its corresponding peritumoral tissue, independently of the tumoral type, and the most pivotal action would seem to minimise exposure to endogenous and exogenous sources of oxidative stress.

Hypoxia-inducible factor-1 alpha (HIF-1alpha) is the major transcriptional factor involved in the adaptive response to hypoxia. The aim of this study was to assess HIF-1alpha in 22 patients with transitional meningioma (TM) and 26 patients with glioblastoma multiforme (GBM). HIF-1alpha was assessed using a commercially available enzyme-linked immunosorbent assay-based HIF-1 transcription factor assay. Levels of HIF-1alpha in TM and GBM were measured using optical density at 450nm, and median values were found to be 0.35 for TM and 0.37 OD for GBM, respectively. There was no statistically significant difference between the two types of tumor (p=0.264). These findings indicate that HIF-1alpha is elevated in both TM and GBM, suggesting that although hypoxia is one of the most important and powerful stimuli for HIF-1alpha elevation and consequently angiogenesis, other mechanisms may play roles in HIF-1alpha stimulation in benign brain tumors such as TM.

Purpose: The aim of this study was to assess glutathione peroxidase (GPx), glutathione reductase (GRx) and protein oxidation (POx) levels in patients with glioblastoma multiforme (GBM) and transitional meningioma (TM) and to compare with normal brain tissues., Methods: GPx, GRx and POx levels were measured in 48 brain tumors obtained during surgery and 15 normal brain tissues that were collected during autopsy. Results were compared between two groups., Results: GPx and GRx activities were significantly lower in GBM and TM when compared to controls and the difference was statistically significant (P = 0.0001). Furthermore, the decrease in enzyme activities was more evident in GBM than in TM. In contrast, POx levels were found to be higher in both GBM and TM compared to controls and showed statistically significant difference (P = 0.00001). Increase in POx levels was clearer in GBM than TM., Conclusions: GPx and GRx decreased and POx increased significantly in both GBM and TM when compared to normal brain tissues. Further, clinical studies with a larger patient population are required to show the role(s) of antioxidant enzymes in brain tumors more accurately.