Mikhail M. Kontorshchikov

Introduction. In glial tumors, lipid metabolism becomes abnormal. Analysis of lipid metabolism components can be an important characteristic of molecular and genetic profile of gliomas.Aim. To determine the correlation between plasma lipidome profile and immunohistochemical characteristics of glial tumors and to evaluate clinical significance of blood lipid spectrum analysis in preoperative assessment of molecular profile of gliomas.Materials and methods. Immunohistochemical measurement of O-6-methylguanine-DNA-methyl transferase (MGMT), Ki-67, p53, IDH1 tumor markers was performed using the corresponding antibody clones. Composition of plasma lipids was assessed using thin layer chromatography.Results. Even at the early stages of gliomagenesis, significant differences in cholesterol ethers, lysophosphatidylcholines, phosphatidylcholine (PC)/ lysophosphatidylcholine (LPC) ratio, neutral lipids (NL)/phospholipids (PL) in the blood were observed. Significant correlations between Ki-67, MGMT tumor markers and the above-mentioned lipidome parameters were found. The PC/LPC, NL/PL ratios in the blood of the patients from the groups with higher (above 10 %) and lower (below 10 %) Ki-67 mitotic indexes compared to healthy individuals were significantly lower. Therefore, the values of lipidome parameters allow to indirectly assess proliferative activity of gliomas which can be used for preoperative diagnosis of these tumors. No significant differences in the plasma PC/LPC and NL/PL ratios were found between the groups with MGMT promoter methylation and without it. No indirect predictor criteria for MGMT were found.Conclusion. It is impossible to determine decreased epigenetic activity of corresponding transcripts and preoperative prognosis for alkylating agent therapy based on the parameters of plasma lipid metabolism.

Background. The peritumoral zone contributes to the progression of gliomas due to its altered metabolism. Superoxide dismutase is one of the main antioxidant defense enzymes; it may be related to gliomagenesis, since the activation of free radical oxidation provokes tumor transformation of cells. Aim. Analysis of superoxide dismutase activity in different areas of the tumor depending on the status of gliomas molecular genetic markers. Material and methods. The surgical material of 20 patients with gliomas of various degrees of anaplasia was analyzed. The brain tissue of people who died as a result of trauma (6 people) served as a control. The status of tumor markers was assessed immunohistochemically. Superoxide dismutase activity and free radical activity were determined in tumor and brain tissue homogenates using Fe-induced biochemiluminescence. For statistical analysis, the computer program StatPlus 6 with the Analyst Soft Inc package was used. Data analysis was carried out using nonparametric methods of statistical processing of the material using nonparametric criteria (MannWhitney U test, KolmogorovSmirnov test, Spearman's rank correlation coefficient). Results. With active tumor growth (Grade IV), free radical activity and superoxide dismutase activity in the peritumoral zone were higher than in intact tissue. Superoxide dismutase activity in the peritumoral zone showed significant correlations: positive with the cell proliferation marker Ki-67 (rs=0.858) and negative with mutations in the isocitrate dehydrogenase (IDH) gene (rs=0.514) and methylation of the O-6-methylguanine-DNA-methyltransferase promoter (rs=0.766). The activity of the peritumoral zone enzyme differed depending on the molecular genetic profile of gliomas. Bioinformatic analysis of interactions between superoxide dismutase and molecular genetic markers of gliomas using the STRING, BioGrid, Signor, and SignaLink databases revealed the presence of mediated interactions with IDH1 with a clustering coefficient of 0.945. This level of clustering indicates the biological relationship of IDH1 with the main enzymes of the antioxidant system, superoxide dismutase and catalase. Conclusion. Significant correlations of superoxide dismutase activity in the peritumoral zone with the status of a tumor markers number and significant differences in enzyme activity in groups depending on the molecular genetic profile suggest the importance of assessing superoxide dismutase activity as a factor in the gliomas progression.

This research was aimed at investigating the features of free radical activity and the parameters of glutathione metabolism in tumor tissues and the peritumoral zone at different degrees of glial tumor anaplasia. We analyzed postoperative material from 20 patients with gliomas of different degrees of anaplasia. The greatest differences compared to adjacent noncancerous tissues were found in the tumor tissue: an increased amount of glutathione and glutathione-related enzymes at Grades I and II, and a decrease of these parameters at Grades III and IV. For the peritumoral zone of Grades I and II, the indices changed in different directions, while for Grades III and IV, they occurred synchronously with the tumor tissue changes. For Low Grade and High Grade gliomas, opposite trends were revealed regarding changes in the level of glutathione and the enzymes involved in its metabolism and in the free radical activity in the peritumoral zone. The content of glutathione and the enzymes involved in its metabolism decreased with the increasing degree of glioma anaplasia. In contrast, free radical activity increased. The glutathione system is an active participant in the antioxidant defense of the body and can be used to characterize the cell condition of gliomas at different stages of tumor development.

This research aimed to investigate the relationships between the parameters of glutathione metabolism and the immunohistochemical characteristics of glial tumors. Postoperative material from 20 patients with gliomas of different grades of anaplasia was analyzed. Bioinformatic analysis of the interactions between the gliomas’ immunohistochemical markers and their glutathione-dependent enzymes was carried out using the STRING, BioGrid, while Signor databases revealed interactions between such glioma markers as IDH and p53 and the glutathione exchange enzymes (glutathione peroxidase, glutathione reductase, glutathione S-transferase). The most pronounced relationship with glutathione metabolism was demonstrated by the level of the nuclear protein Ki67 as a marker of proliferative activity, and the presence of the IDH1 mutation as one of the key genetic events of gliomagenesis. The glutathione system is an active participant in the body’s antioxidant defense, involving the p53 markers and MGMT promoter methylation. It allows characterization of the gliomal cells’ status at different stages of tumor development.

This research aimed to investigate the interrelationship of carbohydrate metabolism parameters and immunohistochemical characteristics of glial tumors. Tumor tissue, peritumoral area, and adjacent noncancerous tissue fragments of 20 patients with gliomas of varying degrees of anaplasia were analyzed. The greatest differences in the carbohydrate metabolism compared to adjacent noncancerous tissues were identified in the tumor tissue: reduction in the levels of lactate and glycogen synthase kinase-3β. Significant differences with adjacent noncancerous tissues for the peritumoral zone were not found. The activity of the carbohydrate metabolism enzymes was different depending on the immunohistochemical glioma profile, especially from Ki 67 level. Bioinformatic analysis of the interactions of immunohistochemical markers of gliomas and carbohydrate metabolism enzymes using the databases of STRING, BioGrid, and Signor revealed the presence of biologically significant interactions with glycogen synthase kinase 3β, hexokinase, glucose-6-phosphate dehydrogenase, and transketolase. The established interconnection of glycolysis with methylation of the promoter of O-6-methylguanine-DNA-methyltransferase (MGMT) of gliomas can be used to increase chemotherapy efficiency.

Orthopedic treatment is of particular difficulty in the complex therapy and rehabilitation of patients with precancerous diseases of the oral mucosa. In this regard, in patients with chronic inflammatory and destructive lesions of the oral mucosa, it is necessary to control changes in the oral cavity, taking into account clinical and laboratory data. Oral fluid is most often used as a diagnostic material in dental research, the composition and properties of which reflect functional changes in the body. However, the studies that substantiate rational orthopedic treatment in such patients are extremely insufficient: there are no data on the effect of orthopedic structures on the primary metabolism in the oral cavity in patients with precancerous diseases. In this regard, the purpose of this work was to study the biochemical parameters of the oral fluid in patients using orthopedic structures to identify the prognostic factors of precancerous conditions. In the oral fluid, the levels of total protein, total cholesterol, triglycerides, and lactate were determined. Free radical oxidation was assessed by the intensity of induced biochemiluminescence and by the levels of lipid peroxidation products. In the oral fluid of patients with mucosal precancer compared with patients in the control group, a significantly higher intensity of free radical oxidation was revealed with a corresponding decrease in antioxidant activity. The level of the end products of lipid peroxidation - Schiff’s bases - was statistically significantly increased. Among the metabolites of the oral fluid, there was a decrease in protein levels and an increase in cholesterol and lactate levels. At the same time, a positive correlation was established between the indicators of free radical oxidation and lactate, free radical oxidation and cholesterol, but negative with the levels of protein and triglycerides. Regarding the antioxidant system, there was a negative correlation between the tg (-2α) value and the lactate level and positive with the triglyceride level, as well as a positive correlation between the Z parameter and the total protein level. The obtained changes in the biochemical parameters of the oral fluid can be used to confirm the diagnosis of precancer of the oral mucosa in patients with orthopedic structures.

It has been established that the non-neuronal cholinergic system is related to the oncogenesis which increases the attractiveness of its components as the promising markers of oncologic diseases. The purpose of this work is to evaluate the clinical significance of the analysis of the activity of acetyl cholinesterase as a new marker of gliomas. The activity of acetyl cholinesterase was assessed by photo colorimetric analysis according to the Hestrin method recalculating the activity of the enzyme in the tumor tissue per 1 g of protein, and in the blood - by 0.1 g of hemoglobin. The data obtained in the primary tumors of the brain (28) in the tissue of the brain of persons who died as a result of injury (6) and in whole blood of patients with gliomas (28) and practically healthy people (10) were compared with the use of a number of statistical programs. A significant decrease in the activity of acetyl cholinesterase in tumor tissue and in whole blood is revealed as the degree of anaplasia of tumors increases, starting with Grade II. It is for the first time that a significant direct correlation was noted showing the consistency between the decrease in the activity of acetyl cholinesterase in the tumor tissue of the brain and blood. Bioinformatic analysis showed the connection of the enzyme of acetyl cholinesterase with proteins of the PI3K-AKT and Notch signaling pathways providing antiapoptotic and proliferative effects. The found dependences provide new insights into understanding of the mechanisms of gliomas genesis and can be used for selection of new diagnostic markers of brain tumors.

Purpose of the study: to assess the state of lipid peroxidation processes in patients with kidney cancer in relation to the clinical factors of the prognosis of the disease and against the background of surgical intervention.Material and methods. For the study, we used blood plasma samples from 300 patients with kidney cancer T1–4N 0–1M0–1, obtained before surgery and 8–9 days after surgery. Oxidative stress was assessed by the intensity of free radical processes by the method of induced biochemiluminescence on the BKhL-07 biochemiluminometer apparatus (Medozons Co., Russia), the activity of lipid peroxidation processes was assessed by the accumulation of initial products in the blood plasma – diene conjugates (DC), triene conjugates (TC) and fial Schiff bases (OSh) according to I. A. Volchegorsky et al. method. (1989). Statistical processing of the results was carried out using Statistica 12 and Microsoft Offie Excel 2010 programs.Results. In patients with kidney cancer, there was a decrease in the level of DC, an increase in OSh and the ratio of Osh / (DC + TC) compared with the control (p ≤ 0.05), against the background of depletion of the resources of the antioxidant defense system. The content of DC did not differ from the norm with the size of the primary tumor of the kidney pT1–pT2 and decreased (p ≤ 0.05) in the case of the presence of the tumor pT3–pT4. At the same time, there was an increase in the OSh content (p ≤ 0.05). In patients with thrombi in the inferior vena cava system, a decrease in the level of DC was observed (p ≤ 0.05), the OSh level did not differ from that of healthy individuals. In the postoperative period, there was an increase in the content of DC (p ≤ 0.05) and a decrease in the Osh / (DC + TC) coeffiient (p ≤ 0.05) compared with the initial level.Conclusion. Kidney cancer is accompanied by the activation of free radical oxidation processes against the background of depletion of the resources of the antioxidant defense system. Changes in the pro-antioxidant homeostasis are interrelated with the size of the primary tumor and the presence of a tumor thrombus. In the postoperative period, the activity of free radical oxidation processes in the patient’s body decreases.

Analysis of long-term treatment results of 101 primary gastric cancer patients at various stages of the tumor process followed during 1 - 41 months (median - 6,4 months) from the onset of specific treatment are presented depending on the levels of soluble forms (s) of PD-1 receptor and its ligand PD-L1 in blood plasma. Overall survival assessed by Kaplan-Meyer analysis and with the help of Cox multiparametric regression model was applied as the criterion of prognostic value. It was found that at high (≥ 35 pg/ml) sPD-L1 levels in blood plasma, the overall survival of patients with gastric cancer was statistically significantly lower than at the marker’s levels below 35 pg / ml (p <0.045): 1-year survival comprised 78 and 96%, 2-year - 52 and 78%; 3-year - 40 and 61% at high and low sPD-L1 respectively. Median survival of patients with high plasma sPD-L1 comprised 29 months, of those with low sPD-L1 was not achieved during the whole follow-up period. This trend was observed not only in the total group of stage I-IV gastric cancer patients, but also in patients at the early stages of the disease, though sPD-L1 did not show an independent prognostic value in multiparametric model. At the same time, the overall survival of patients with gastric cancer did not depend on the baseline levels sPD-1 in blood plasma. Thus, soluble ligand sPD-L1 can be considered as a potentially valuable factor for prognosis of gastric cancer patients’ survival, and, probably, of anti-PD-1/PD-L1 treatment efficiency, but further studies and patients’ monitoring are required to prove this statement.