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Oxidative DNA damage plays a significant role in pathogenesis of the majority of pathological processes, which occurs in case of excessive formation of ROS due to intense prooxidant effects or reducing the antioxidant defense system. The study has shown that oxidative stress causes endothelial dysfunction, which leads to high blood pressure stabilization in patients with AH.The study included 42 men (mean age 37,1±6,0 years) with AH, who worked from 4 to 22 years (mean age 14,6±6,8 years) under the influence of UHF EMR (group 1). The dose of UHF EMR was within the range of 4320-31065 kW (16288,7±7844,9 kW average). The control group consisted of male patients of respective age with AH, who were not exposed to prolonged UHF EMR (group 2, n=35). Body mass index in patients of group 1 was 28,5±4,7 kg/m2, patients of group 2 -29,8±3,9 kg/m2.5 days after admission, all patients underwent daily blood pressure monitoring using the ABMP-04 "Meditech" monitors (Hungary) and were daily measured for urine marker of oxidative DNA damage 8-oxoguanine (8-oxoG) by spectrophotometry using the SF-46 unit.Daily average systolic blood pressure in 1 group of patients was 144,3±12,8 mmHg vs. 126,3±11,8 mmHg in patients of the control group (P<0,05), diastolic blood pressure 83,2±5,9 mmHg vs. 79,4±10,5 mmHg (P<0,05) respectively.The average rate of 8-oxoG excretion in group 1 patients significantly exceeded the value of those in group 2 (16,3±4,9 nmol/kg/day vs. 11,7±3,1 nmol/kg/day, P<0,05).A significant (P<0,005) direct correlation discovered between the blood pressure level and excretion rate of oxidative DNA damage marker (r=0,52), the negative relationship between the daily excretion rate of 8-oxoG and work experience (r=-0,63; P<0,001).In patients who protractedly worked in conditions of UHF EMR , the rate of DNA damage increased, which, possibly due to the genome operation instability in endothelial cells, determined the high daily average level and low blood pressure control. The results can be used as a marker of oxidative stress during the damaging influence of UHF EMR on human's body. [ABSTRACT FROM AUTHOR]

Magnetic nanocomposites (MNC) are promising theranostic platforms with tunable physicochemical properties allowing for remote drug delivery and multimodal imaging. Here, we developed doxorubicin-loaded Fe 3 O 4 -Au MNC (DOX-MNC) using electron beam physical vapor deposition (EB-PVD) in combination with magneto-mechanochemical synthesis to assess their antitumor effect on Walker-256 carcinosarcoma under the influence of a constant magnetic (CMF) and electromagnetic field (EMF) by comparing tumor growth kinetics, magnetic resonance imaging (MRI) scans and electron spin resonance (ESR) spectra. Transmission (TEM) and scanning electron microscopy (SEM) confirmed the formation of spherical magnetite nanoparticles with a discontinuous gold coating that did not significantly affect the ferromagnetic properties of MNC, as measured by vibrating-sample magnetometry (VSM). Tumor-bearing animals were divided into the control (no treatment), conventional doxorubicin (DOX), DOX-MNC and DOX-MNC + CMF + EMF groups. DOX-MNC + CMF + EMF resulted in 14% and 16% inhibition of tumor growth kinetics as compared with DOX and DOX-MNC, respectively. MRI visualization showed more substantial tumor necrotic changes after the combined treatment. Quantitative analysis of T 2 -weighted (T 2 W) images revealed the lowest value of skewness and a significant increase in tumor intensity in response to DOX-MNC + CMF + EMF as compared with the control (1.4 times), DOX (1.6 times) and DOX-MNC (1.8 times) groups. In addition, the lowest level of nitric oxide determined by ESR was found in DOX-MNC + CMF + EMF tumors, which was close to that of the muscle tissue in the contralateral limb. We propose that the reason for the relationship between the observed changes in MRI and ESR is the hyperfine interaction of nuclear and electron spins in mitochondria, as a source of free radical production. Therefore, these results point to the use of EB-PVD and magneto-mechanochemically synthesized Fe 3 O 4 -Au MNC loaded with DOX as a potential candidate for cancer magnetic nanotheranostic applications., Competing Interests: Authors declare no conflicts of interest., (This journal is © The Royal Society of Chemistry.)

Background: The current studies demonstrate that SARS-CoV-2 infection results in increasing complications incidence and the total risk of death in cancer patients. SARS-CoV-2 infection triggers oxidative stress representing one of the major factors of the inflammation contributing to the complicated course of the diseases including cancer., Aim: To assess the effect of hypoxia caused by SARS-CoV-2 infection on the redox status of blood in patients with metastatic colorectal cancer (mCRC)., Materials and Methods: 10 patients with SARS-CoV-2, 11 mCRC patients with metachronous liver disease, and 14 mCRC patients with preceding SARS-CoV-2 infection were included in the study. The data on blood biochemistry (C-reactive protein, ferritin, transferrin, and free iron) were analyzed. The levels of superoxide radicals (ROS) in blood cells were determined by electron paramagnetic resonance (EPR) using the spin trap technique. The metalloproteinase activity was measured by polyacrylamide gel zymography with the addition of gelatin as a substrate., Results: In mCRC patients with prior SARS-CoV-2 infection, a 1.26-fold increase in ROS-generating activity of blood neutrophils was observed compared to mCRC patients with no history of SARS-CoV-2 infection. The blood content of C-reactive protein, transferrin, and free iron in mCRC patients with prior SARS-CoV-2 infection increased by 2, 6, and 1.4 times, respectively. The total activity of gelatinases in platelets and neutrophils in the blood of mCRC patients with prior SARS-CoV-2 infection was 1.4 and 1.2 times higher compared to mCRC patients with no history of SARS-CoV-2 infection., Conclusion: mCRC patients with prior COVID-19 have a higher risk of exacerbation of inflammatory reactions. SARS-CoV-2 infection results in redox dіsbalance, which may contribute to the unfavorable course of the disease.

Aim: To assess the inducible NO-synthase activity and the total RNase activity in tissue samples and blood neutrophils of the patients with prostate intraepithelial neoplasia (PIN) and prostate cancer (PCa) of different stages., Materials and Methods: NO level was measured in tumor tissue and neutrophils of patients with PIN and PCa of different stages by electron paramagnetic resonance using the spin traps technology. RNase activity in tumor tissue of patients with PIN and PCa was measured by the method of zymography., Results: We have found that NO levels in prostate tumor tissue were significantly higher than in the PIN and increased along with the disease progression. Analysis of NO level in neutrophils of the PCa patients demonstrated that the values were not dispersed and did not depend on the stage of disease. NO level in neutrophils of the PCa patients increased manifold as compared with that in healthy donors. At the same time, the RNase activity in the prostate tumor tissue gradually decreased with PCa progression., Conclusion: Activities of inducible NO-synthase and RNases change significantly with progression of PCa.

Aim: To study the levels of redox-forming molecules generated in tumor, adipose tissue (AT), neutrophils and platelets of patients with colorectal cancer (CRC) with normal body weight or obesity., Materials and Methods: 83 samples of tumor tissue and 83 samples of the AT taken at the distance of 5 cm from the tumor as well as 83 blood samples have been analyzed in the patients with CRC with metachronous lesions in liver. The comparison group consisted of 18 patients who were surgically treated for ulcer. The rates of free radical generation were measured by electron paramagnetic resonance., Results: Free radical generation rate in tumor tissue and AT increased and nitrogen oxide (NO) levels decreased in patients with body mass index ≥ 25 kg/m 2  as compared to the patients with normal body weight (p < 0.05). The superoxide generation activity in neutrophils of CRC patients exceeded about 7-fold the values obtained in neutrophils from patients with ulcer while the NO levels produced by neutrophils of CRC patients decreased significantly (p < 0.01). The same trends held true for the platelets., Conclusions: In obese patients with CRC, superoxide-generating activity increases in cancer cells, AT, neutrophils and platelets. The obesity should be considered as the additional oncological risk representing the potent predictor for the events realized in obese patients such as oxidative stress, inflammation, insulin resistance and endothelial dysfunction.

Background: The resection of metastases within healthy parenchyma improves significantly the long-term outcome in metastatic colorectal cancer. Until now, the resection technique involves Pringle maneuver, which allows reducing blood loss during transsection of liver parenchyma. However, the classical Pringle maneuver has restrictions due to ischemia/reperfusion (I/R) effect, in particular increasing risk of tumor recurrence after liver surgery., Aim: To study the pathological impact of surgical intervention and I/R effect on healthy liver tissue in the experimental setting by evaluating the markers of redox-homeostasis and oxidatively induced mutage-nesis, and also to assess the current possibilities of their correction by application of drag-reducing polymers (DRPs)., Materials and Methods: MC38 mouse colon adenocarcinoma cells were transplanted intrahepatically to C57Bl/6 mice. The influence of warm ischemia on metastatic potential of MC38 cells, the speed of superoxide radicals (SR) generation and 8-hydroxydeoxyguanosine content were studied., Results: In case of modeled liver metastases, the surgery initiates an increase in the rate of SR generation into the remaining liver tissue and, consequently, provokes its ischemic injury. The application of DRPs protects liver tissue under I/R conditions., Conclusions: The warm I/R can promotes metastatic lesions in the healthy part of the organ with underlying increase in the rate of SR generation and oxidatively induced damage of guanine in DNA. The hemorheological effects of DRPs ensure increase of microcirculatory perfusion and oxygenation of liver tissues with the reduction of the rate of SR generation and decrease of 8-hydroxydeoxyguanosine as a marker of oxidatively induced mutations in DNA of hepatocytes. The intraperitoneal administration of nanomolar doses of DRPs prevents the activation of the growth of dormant metastatic MC38 cells in the liver. Further experimental and clinical study of these substances will allow reducing the risks of activation of uncontrolled tumor growth in the liver due to the pathological effect of post-operative I/R.

Excess body weight has been causally linked to an increased risk of different cancer types, including gastric cancer but the mechanisms underlying this relationship are not well understood. Superoxide generation rate, activity of complex I in electron transport chain of mitochondria, activity of matrix metalloproteinase (MMP-2 and 9) of adipose tissues (AT) of patients with gastric cancer in AT located adjacent to tumor (ATAT) and at a distance of 3 cm (ATD) are measured to follow the connection of the redox state with some of the microenvironment indicators (HIF-1α, CD68, Plin5), body mass index (BMI) and cancer metastasis. Superoxide generation rate in ATAT positively correlates with BMI (r = 0.59, p < 0.05) being 4 times higher than in control (p < 0.05). MMP-2, 9 activities in ATAT positively correlate with BMI (r = 0.67, p < 0.05) being 3.3-4.0 higher than in control (p < 0.05). In ATD a statistically significant increase of MMP-2 activity is found. In ATAT for the group of patients with distant metastasis (M1) the superoxide generation rate, MMP-2, 9 activities are about 2 times higher (p < 0.05) than in the subgroup without distant metastases (M0). M1 is also characterized by the increased values of HIF-1α+ (factor 1.25), CD68+ (factor 1.4) and Plin5+ (factor 2.1) compared to M0 category in tumor tissues (p < 0.05). The results can be used for better understanding the mechanism(s) of symbiosis of tumor and adipose tissues as well as serve as a basis for new therapeutic approaches., (Copyright © 2019 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.)

Background: Interaction between tumor cells and tumor microenvironment is critical for homeostasis of normal cells and tumor growth. Tumor cell - stroma interaction represents the potent factor able to initiate cancer and affect tumor progression and disease outcome. The tumors vary by their origin and microenvironment (proportion of stromal cells, their composition and activation state). The surgical stress and tumor microenvironment may potentiate acute hepatic failure in the patients with metastatic colorectal cancer (mCRC). Pathological effect of ischemia-reperfusion (I/R) consists in the increased generation of superoxide radicals (SR) and nitrogen oxide (NO) affecting the postresectional regeneration of liver tissue. Redox state of hepatic tissue in I/R setting upon resection of metastases may trigger the aggressiveness of residual cancer cells and regeneration or degradation of hepatic tissue. The aim of the study was to analyze redox state of hepatic tissue following surgery with Pringle maneuver (PM) in the patients with mCRC., Materials and Methods: mCRC samples from 145 patients treated at National Cancer Institute, Ministry of Health of Ukraine, were analyzed. The patients obtained chemotherapy according to the approved international and national standards as well as clinical protocols. Two groups of patients were delineated according to the duration of the interruption of blood inflow due to PM, namely ≤ 45 min and > 45 min. The activity of FeS proteins in the electron transport chain (ETC) in mitochondria and lactoferrin (LF) level in the tissues were assessed by EPR (77К). The rates of SR and NO generation were determined with spin traps. The activity of matrix metalloproteinase (MMP)-2 and -9 was measured by gelatin zymography using SDS-polyacrylamide gel electrophoresis., Results: In tissue of liver resected in the setting of > 45 min ischemia, ETC function in mitochondria was impaired (decreased activity of FeS protein of N-2 ETC complex I due to interaction with NO). This results in the hypoxia state and glycolysis with uncontrolled SR generation. In addition, the efficiency of detoxification system in hepatocytes is reduced substantially with increase in semiquinone and LF levels as well as MMP-2 and -9 activity as compared with liver without metastatic lesions that was not affected by I/R., Conclusions: The ischemic injury of liver in the setting of metastasis resection results from cell response to interruption of blood flow followed by reperfusion. The key factor in the genesis of reperfusion damage is uncontrolled increase of the levels of SR and their metabolites - reactive oxygen species as well as the increased MMP activity. Also, liver tissue affected by I/R contains high levels of xanthine oxidase metabolizing hypoxanthine and monoamine oxidase deaminizing biogenic amines. Both processes are the sources of SR.

The high incidence of recurrence and metastasizing in colorectal cancer (CRC) poses the challenge for the improvement in long-term treatment outcome., Aim: To determine the major indicators of redox-formative molecules in the tissue of metastatic CRC (mCRC), stages Т2-4N0-2M0G2-3, namely the rate of superoxide radical (SR) generation, nitric oxide (NO) content, the activity of matrix metalloproteinases (MMP), lactoferrin (LF) content, and "free" iron and their association with some clinical and pathological characteristics of the patients., Materials and Methods: mCRC samples from 51 patients were analyzed (stage II, 31 patients; stage III, 20 patients). The LF and "free" iron were assessed by electron paramagnetic resonance (EPR) at the temperature of 77 °K. The rate of SR and NO generation was determined with spin traps (ТЕМРО-Н, diethyl dithiocarbamate). The activity of MMP-2 and -9 was measured by gelatin zymography using SDS-polyacrylamide gel electrophoresis. Ki-67 expression was analyzed by immunofluorescence technique., Results: In tumors with metastases into the regional lymph nodes (N1-2 category), SR generation rate was 2.2-fold higher than in the tumors categorized as N0. In G3 mCRC, SR generation rate was 1.7-fold higher than in G2-tumors (p < 0.05). The rate of SR generation correlated inversely with differentiation grade of the tumor (r=-0.61; p < 0.05). MMP-2 and -9 activities in mCRC tissue correlated with SR generation rate and NO level (r = 0.44 ÷ 0.53, p < 0.05). The direct correlation between LF content and the stage of the disease (r = 0.42) and "free" iron content (r = 0.61) was demonstrated while the correlation between LF content and tumor differentiation grade was inverse (r = -0.57; p < 0.05)., Conclusions: The altered tumor-associated redox state in mCRC tissue contributes to the increased cell proliferation and formation of aggressive phenotype of the tumor. The assays for the content of redox-formative components in mCRC may be used as additional prognostic markers of the course of the disease in CRC patients.

Prognosis of metastatic colorectal cancer (mCRC) patients nowadays is an important subject in the field of oncology. R0-resection of colon with primary tumor and liver metastasis remains the only treatment which significantly improves survival rate. However, recent experimental data show that surgical trauma can indirectly stimulate tumor growth due to mitochondrial dysfunction and unregulated superoxide radical (O2-) generation., Aim: To study the clinical significance of 8-oxo-2'-deoxyguanosine (8-oxodGu) marker, to assess the oncological effects of warm ischemia of liver parenchyma on disease prognosis in patients with mCRC., Material and Methods: 69 urine 24-hour volume tests of patients with mCRC and 17 healthy individuals were studied. Urine 8-oxodGu level was measured using spectrophotometric method with pre-solid phase DNA extraction. The energy system and hepatocyte detoxification system state, levels of O2- in tumor tissue were determined using the method of electron paramagnetic resonance (EPR) and SpinTraps technology at room temperature. Experiments were carried out on a computerized EPR spectrometer RE-1307. EPR spectra were recorded at temperature of liquid nitrogen (196C) in paramagnetically pure quartz dewar on a computerized spectrometer PE-1307 with resonator H011. Error of the method of spectrum integration and spread of spectrum reproduction of one sample was not more than 3%., Results: The average level of marker in healthy individuals was 0.244 day, whereas before the resection and on day 3 after the R0-resection of liver in mCRC patients was 3.42 day and 2.12 day (p < 0.05), respectively. On day 3 after the liver resection due to its metastatic lesions with a total duration of warm ischemia period < 30 min and > 30 min have had marker at level 2.108 day and 2.9883 day (p < 0.0001), respectively. The volume of metastatic tissue significantly and directly correlated with the level of urine 8-oxodGu (R 2 =0.54, 95% CI 0.0370.0991, p < 0.0001), also duration of surgical intervention (300 min) and duration of worm liver ischemia ( 30 min) during the surgery significantly increased urine level of 8-oxodGu (R 2 =0.54, 95% CI 0.001 0.004, p < 0.001)., Conclusions: Warm liver ischemia (> 30 min), long-term surgical intervention ( 300 min) and metastatic tissue volume ( 12 cm 3 ) in liver parenchyma in mCRC patients significantly increase urine 8-oxodGu levels. R0-resection of liver metastases in mCRC patients decreases urine 8-oxodGu levels already on day 3 after the surgery. 8-oxodGu is a new factor of oncological prognosis in patients with mCRC.

Aim: To investigate the content of essential elements (EE): copper, zinc, magnesium, iron and calcium and the evaluation of the activity of metal-containing enzymes - ceruloplasmin (CP), myeloperoxidase (MPO) and the content of transferrin (TF) in blood plasma (BP) and tumor tissue (TT) of animals with Walker-256 carcinosarcoma treated with lactoferrin (LF)., Materials and Methods: The study of the EE content and the activity of the abovementioned enzymes was carried out on rats with Walker-256 carcinosarcoma treated with LF at the doses of 1 and 10 mg/kg of body weight. The quantitative content of EE in BP and TT of animals was determined using the inductively coupled plasma atomic emission spectroscopy (ICP-AES). Determination of CP activity, content of TF and hemochromes was performed using the method of electron paramagnetic resonance (EPR), and MPO - by unified biochemical method., Results: The introduction of LF at the doses of 1 and 10 mg/kg resulted in a decrease in the ratio of Cu/Zn in BP and even more expressed decrease of Ca/Mg ratio in TT. Administration of LF, especially at a dose of 10 mg/kg, affected the increase in CP and MPO activity in BP. It has been shown that administration of LF at a dose of 10 mg/kg led to an increase in oxidative products of destruction of the hemoglobin-hemochrom system in the TT, against the background of lowering the TF content., Conclusions: The administration of LF, especially at a dose of 10 mg/kg, led to metabolic alterations associated with inhibition of the tumor process. The detected modulating effect of LF on the content of the EE and the activity of the CP and MPO may be a basis for correction of the elemental balance in carcinogenesis.

Aim: To study the effect of Ferroplat (FrP) on the indexes of pro/antioxidant balance and energy metabolism in breast cancer cells of different malignancy degree and different sensitivity to drug therapy., Materials and Methods: The study was carried out on breast cancer cells of low (T47D, MCF-7) and high malignancy degree (MCF-7/DDP (cisplatin-resistant), MDA-MB-231, MDA-MB-468) using cell culture techniques, immunocytochemical, biochemical, biophysical methods, flow cytometry and polarography., Results: We established that the addition of FrP to the culture medium reduces the activity of glucose-6-phosphate dehydrogenase (G6PDH), superoxide dismutase (SOD) and the level of non-protein thiols by 32-41% (p < 0.05). At the same time, there was an increase of the total level of ROS and the rate of NO generation by inducible NO synthase by 1.7-2.5 times (p < 0.05). This testifies that FrP disturbs the antioxidant balance in cells, resulting in their death. Also, the use of FrP led to a decrease in the rate of oxygen absorption in MCF-7 and T47D cells by 26% and 25%, respectively (p < 0.05). In cells of high malignancy degree this index decreased by 38-40% under the influence of FrP. Incubation of MCF-7 and T47D cells with the indicated agent also reduced the content of phospholipid cardiolipin by 15-16% (p < 0.05), and in MDA-MB-231, MCF-7/DDP, MDA-MB-468 cells - by 29%, 30% and 32%, respectively. In addition, the effect of FrP caused a decrease in the levels of Mg2+ and lactate in MCF-7 and T47D cells by 21-29% and 14-24%, respectively, whereas in MDA-MB-231, MDA-MB-468, MCF-7/DDP cells - by 34-38% and 32-35%, respectively. In this case, the agent raised the level of glucose in the cells of low malignancy degree by 20-23% (p < 0.05), and in the cells of high malignancy degree and with the phenotype of drug resistance - by 31-36%. However, the nanocomposite did not affect the activity of lactate dehydrogenase in all studied breast cancer cells., Conclusion: The study has shown that FrP has an effect on the pro/antioxidant balance and energy metabolism of cancer cells. In addition, the denoted effect of FrP was more pronounced in the breast cancer cells with a high malignancy degree and the phenotype of drug resistance.

Excess body weight has been causally linked to an increased risk of different cancer types, including colorectal cancer (CRC) but the mechanisms underlying this association are practically unknown. We investigate redox state-superoxide (SO) generation rate, activity of complex I in electron transport chain (ETC) of mitochondria and of dinitrosyl iron complexes by electron paramagnetic resonance; activity of matrix metalloproteinase (gelatinase) MMP-2 and MMP-9 by gel zymography of adipose tissues (AT) from 46 patients (64.0 ± 1.6 y.o.) with CRC (II-III stages, pT2-3N0-2M0) in the AT adjacent to tumor (ATAT) and at a distance of 3 cm from the tumor (ATD) to follow the connection of the AT redox state with some of the tumor microenvironment indicators. We have incubated the AT species with the tumor necrosis factor α (TNF- α ) to follow its influence on the measured values. As a control, normal AT (NAT) obtained during the liposuction is used. Tumor-induced changes in mitochondrial ETC of ATAT, particularly for Complex I, lead to the enhanced SO generation and consequent oxidative modifications of DNA in ATAT (up to 6.1 times higher than that in NAT and 3.7 times higher than that in ATD, p < 0.05). Gelatinase activity in ATAT is significantly higher than in ATD. A considerable effect of TNF- α on ATAT and ATD (but not on NAT, i.e., only on the tissues where the reprogramming of metabolism has already occurred under the influence of tumor) manifested in increase of cellular hypoxia, gelatinase activity, and SO generation rate is observed. The results can be used for better understanding the mechanism(s) of metabolic symbiosis of tumor and AT as well as serving as a basis for new therapeutic approaches.

A role of pro- and antioxidants for reducing rectal cancer (RC) incidence in operative, preoperative, and postoperative treatments is still disputable and controversial. The redox state of venous blood and tissues of blood vessels of 60 patients with RC (T 2-4 N 0-2 M 0 G 2 ) and 20 donors is studied by means of the conventional and spin-trapping electron paramagnetic resonance (EPR). The intensity of the signals from ceruloplasmin (CP), transferrin (TF), and labile iron pool (LIP) at temperature T = 77 K as well as superoxide generation rate and nitric oxide (NO) levels at T = 300 K is measured. The reduced CP and TF activity and decreased NO levels increased LIP levels and superoxide-generating rates are detected in blood species. Correlation analysis for the five-year survival rate as a function of the extracted values is done. The results show that the intensities of the corresponding EPR signals from the "native" and "trapped" paramagnetic centers can be potentially used for the understanding of the molecular mechanisms underlying the RC progression and treatment.

Aim: To investigate the mechanisms of cytotoxic activity and pro-/antioxidant effect of lactoferrin on hormone receptor-positive and receptor-negative breast cancer cells in vitro., Materials and Methods: The study was performed on receptor-positive (MCF-7, T47D) and receptor-negative (MDA-MB-231, MDA-MB-468) human breast cancer cell lines. Immunocytochemical staining, flow cytometry, low-temperature electron paramagnetic resonance, and the Comet assay were used., Results: Upon treatment with lactoferrin, the increased levels of reactive oxygen species (ROS) (p < 0.05), NO generation rate by inducible NO-synthase (p < 0.05) and the level of "free" iron (p < 0.05) were observed. Moreover, the effects of lactoferrin were more pronounced in receptor-negative MDA-MB-231 and MDA-MB-468 cells. These changes resulted in increased expression of proapoptotic Bax protein (p < 0.05), reduced expression of the antiapoptotic Bcl-2 protein (p < 0.05) and level of not-oxidized mitochondrial cardiolipin (1.4-1.7-fold, p < 0.05). This, in turn, caused an increase in the percentage of apoptotic cells (by 14-24%, p < 0.05). Cytotoxic effects of lactoferrin were accompanied by an increase in the percentage of DNA in the comet tail and blocking cell cycle at G2/M phase, especially in receptor-negative cell lines., Conclusion: The study showed that exogenous lactoferrin causes a violation of an antioxidant balance by increasing the level of ROS, "free" iron and NO generation rate, resalting in the blocking of cell cycle at G2/M-phase and apoptosis of malignant cells.

Aim: To investigate the changes of redox-state of mammalian brain cells as the critical factor of initiation and formation of radiation damage of biological structures in setting of continuous exposure to low doses of ionizing radiation or fractionated ultra high frequency electromagnetic radiation (UHF EMR) at non-thermal levels., Materials and Methods: The influence of low-intensity ionizing radiation was studied on outbred female rats kept for 1.5 years in the Chernobyl accident zone. The effects of total EMR in the UHF band of non-thermal spectrum were investigated on Wistar rats. The rate of formation of superoxide radicals and the rate of NO synthesis in mitochondria were determined by the EPR., Results: After exposure to ionizing or UHF radiation, the levels of ubisemiquinone in brain tissue of rats decreased by 3 and 1.8 times, respectively. The content of NO-FeS-protein complexes in both groups increased significantly (р < 0.05). In the conditions of ionizing or EMR the rates of superoxide radical generation in electron-transport chain of brain cell mitochondria increased by 1.5- and 2-fold, respectively (р < 0.05). In brain tissue of rats kept in the Chernobyl zone, significant increase of NO content was registered; similar effect was observed in rats treated with UHFR (р < 0.05)., Conclusions: The detected changes in the electron transport chain of mitochondria of brain cells upon low-intensity irradiation or UHF EMR cause the metabolic reprogramming of cell mitochondria that increases the rate of superoxide radical generation and nitric oxide, which may initiate the development of neurodegenerative diseases and cancer. This article is part of a Special Issue entitled "The Chornobyl Nuclear Accident: Thirty Years After".

Aim: To assess the influence of the treatment with 5-azacytidine (5-aza) on the profile of metal-containing proteins and factors of their regulation in Guerin carcinoma cells in vivo., Materials and Methods: The study was conducted on Wistar rats transplanted with wild-type Guerin carcinoma (Guerin/WT) and its strains resistant to cisplatin (Guerin/CP) or doxorubicin (Guerin/Dox). Animals were distributed in 6 groups treated with 5-aza and control animals without treatment. 5-Aza was injected by i.v. route (1 injection in 4 days at a dose of 2 mg/kg starting from the 4 th day after tumor transplantation, 4 injections in total). Ferritin levels in blood serum and tumor tissue were measured by ELISA, transferrin and free iron complexes - by low-temperature EPR, miRNA-200b, -133a and -320a levels and promoter methylation - by real-time quantitative reverse transcription polymerase chain reaction., Results: The study has shown that 5-aza treatment caused demethylation of promoter regions of fth1 and tfr1 genes in all studied Guerin carcinoma strains. 5-Aza treatment resulted in a significant decrease of ferritin levels in tumor tissue (by 32.1% in Guerin/WT strain, by 29.8% in Guerin/Dox and by 69.1% in Guerin/CP). These events were accompanied by 3.5-fold and 2-fold increase of free iron complexes levels in tumor tissue of doxorubicin and cisplatin resistant strains, respectively. Also, 5-aza treatment resulted in significantly elevated levels of miR-200b, -133a, 320a expression in tumor tissue. After 5-aza treatment, ferritin levels in blood serum of animals with Guerin/Dox were increased by 23.9%, while in Guerin/Wt and Guerin/CP they were decreased by 17 and 16%, respectively., Conclusion: Alterations of epigenetic regulation upon in vivo treatment with 5-aza change the levels of metal-containing proteins due to DNA demethylation and altered miRNA expression profiles in Guerin carcinoma cells.

High levels of reactive oxygen (ROS) and nitrogen (RNS) species can lead to the destruction of extracellular matrix facilitating tumor progression. ROS can activate matrix metalloproteinases (MMP), damage DNA and RNA. Therefore, the levels of MMP, ROS and RNS can serve as additional prognostic markers and for the estimation of the effectiveness of tumor therapy. Concerning gastric cancer, the prognostic role of MMP, its connection with the cancer staging remains controversial and correlations between the activity of MMP with the ROS and RNS levels are insufficiently confirmed. Superoxide generation rates, nitric oxide (NO) levels, concentrations of active forms of matrix metalloproteinases MMP-2 and MMP-9 in tumor and adjacent tissues of patients with stomach cancer at different disease stages were measured by electron spin resonance (ESR) including spin-trapping and polyacrylamide gel zymography. It is shown that the activity of MMP-2 and MMP-9 in tumor tissue correlate with the superoxide radicals generation rate and NO levels (r = 0.48÷0.67, p < 0.05). The activity of MMP-2 and MMP-9 in tumor tissues and superoxide radical generation rates correlate positively with the stage of regional dissemination (r = 0.45 and 0.37, correspondingly, p < 0.05), but MMP-2 and MMP-9 activity inversely depends on distant metastatic degree of stomach cancer (r = 0.58; p < 0.05). Additionally, the feasibility of ESR to locally determine oxidative stress is demonstrated.

Aim: To study the redox-dependent mechanism of antiradical, antitumor and antimetastatic action of L-arginine hydrochloride (L-Arg) and coenzyme Q10 (CoQ10) in vivo., Materials and Methods: The study was performed on С(57)Вl mice with transplanted Lewis lung carcinoma treated by intraperitoneal injections of L-Arg at low or high doses (60 and 360 mg/kg body weight), CoQ10 (0.2 and 1.2 mg/kg body weight) or their combinations. Electron paramagnetic resonance was applied for analysis of mitochondrial electron transport chain, СoQ10 levels, free iron (FI), the level of NO, and the rate of superoxide radical generation. The activity of matrix metalloproteinase (MMP)-2 and -9 in tumor tissue was determined by zymography method in polyacrylamide gel., Results: Administration of L-Arg at high doses caused an inhibition of tumor growth by 48 ± 8.0%, increase of superoxide radical generation rate and NO levels to a value of 1.23 ± 0.14 and 2.26 ± 0.31 nm/g tissue · min, and decreased activity of MMP-2 and -9 (3.55 ± 0.8 and 4.8 ± 1.0 r.u., respectively). Treatment with L-Arg at low doses stimulated tumor growth and increased the levels of MMP-2 and -9 activities (8.44 ± 2.7 and 9.8 ± 3.1 r.u., respectively). Administration of СoQ10 at high doses significantly decreased superoxide radical generation rate to the values of 0.44 ± 0.09 nm/g tissue · min, levels of free iron and NO, and caused tumor growth inhibition by 54 ± 11.3%. The combined use of L-Arg and СoQ10 at high doses caused tumor growth inhibition by 51 ± 7.4% compared to Lewis lung carcinoma-bearing untreated animals (p<0.05)., Conclusions: Administration of L-Arg and СoQ10 caused the dose-dependent effect on the rate of generation of superoxide radicals, level of ubisemyquinone, complexes NOFeS-proteins, levels of FI and NO. L-Arg at low doses positively modulated MMP-9 activity that promoted tumor progression. Upon combined use of L-Arg and СoQ10, superoxide radicals and NO form the redox state that causes decrease of MMP-2, -9 activities with consequent inhibition of tumor invasion and metastasis.

The study was aimed at determining the changes of metal-containing proteins in blood serum and tumor tissue of animals with parental and doxorubicin-resistant strains of Walker-256 carcinosarcoma before and after the cytostatic administration. It has been shown that upon doxorubicin action the levels of total iron and transferrin in the tissues from the both groups of animals decreased while that of ferritine simultaneously increased with more pronounced pattern in the group of animals with resistant tumor strain. It has been shown that upon the action of doxorubicin in tumor tissue of animals with different sensitivity to the cytostatic there could be observed oppositely directed changes in the redox state of these cells that in turn determined the content of “ free iron” complexes, RO S generation and concentration of active forms of matrix metaloproteinase- 2 and matrix metaloproteinase-9, namely, the increase of these indexes in animals with parental strain and their decrease in animals with the resistant one. So, our study has demonstrated the remodulating effect of doxorubicin on the state of metal-containing proteins and redox characteristics of tumor dependent on its sensitivity to cytostatic, at the levels of the tumor and an organism. These data may serve as a criterion for the development of programs for the correction of malfunction of iron metabolism aimed at elevating tumor sensitivity to cytostatic agents.

Aim: To study the cytostatic and some biological effects of aminoferrocene using mice with L1210 lymphoid leukemia., Materials and Methods: Experiments were performed on BDF1 male mice (DBA/2, female × C57Bl/6, male) with transplantable L1210 lymphoid leukemia. Determination of antitumor activity of Benzyl-Fc Boron (Bn), it was injected intraperitoneally 6 times daily, starting on day 2 after L1210 leukemia cell transplantation. Doses of Bn such as 26; 260 and 2600 μg/kg were used. The determination of intracellular content of cardiolipin, thiols, reactive oxygen species (ROS) and also analysis of Annexin V positivity and mitochondrial transmembrane potential (JC-1 staining) were performed with use of flow cytometry. The levels of "free iron" complexes, transferrin active forms and the rate of NO generation were measured by EPR-specroscopy., Results: Six daily injections of Bn at a dose of 26 μg/kg resulted in an increased survival of mice with L1210 leukemia by 28% (p < 0.05). Bn led to an increase of apoptotic cells number and ROS amount in leukemia cells. Besides, Bn caused a decrease of cardiolipin and nonprotein thiol compounds content. The membrane electrochemical potential of cell mitochondria was decreased also after Bn administration. Studies using EPR-spectroscopy revealed a significant increase in a level of "free iron", content of transferrin active species and generation rate of NO by inducible NO-synthase in L1210 cells after aminoferrocene administration., Conclusion: Our data indicate that Benzyl-Fc Boron can be promising candidate for realizing a new strategy of anticancer therapy with the use of ROS-inducing agents.

The study was focused on the detection of changes in serum and tumor metal-containing proteins in animals during development ofdoxorubicin-resistant phenotype in malignant cells after 12 courses of chemotherapy. We found that on every stage of resistance development there was a significant increase in content of ferritin and transferrin proteins (which take part in iron traffick and storage) in Walker-256 carc'inosarcoma tissue. We observed decreased serumferritin levels at the beginning stage of the resistance development and significant elevation of this protein levels in the cases withfully developed resistance phenotype. Transferrin content showed changes opposite to that offerritin. During the development of resistance phenotype the tumor tissue also exhibited increased 'free iron' concentration that putatively correlate with elevation of ROS generation and levels of MMP-2 and MMP-9 active forms. The tumor non-protein thiol content increases gradually as well. The serum of animals with early stages of resistance phenotype development showed high ceruloplasmin activity and its significant reduction after loss of tumor sensitivity to doxorubicin. Therefore, the development of resistance phenotype in Walker-256 carcinosarcoma is accompanied by both the deregulation of metal-containing proteins in serum and tumor tissue and by the changes in activity of antioxidant defense system. Thus, the results of this study allow us to determine the spectrum of metal-containing proteins that are involved in the development of resistant tumor phenotype and that may be targeted for methods for doxorubicin sensitivity correction therapy.

Unlabelled: Study was aimed to analyze the dynamics of changes and study interrelations between content of ferritin, transferrin, active gelatinases (MMP-2 and -9) in blood serum and tumor tissue, free iron, rate of superoxide radicals generation in tumor, activity of NADPH-oxidase and iNOS in neutrophils rats with sensitive and resistant strains of Guerin carcinoma (GC)., Materials and Methods: In order to obtain resistant tumor, 12 courses of cisplatin chemotherapy have been carried out on rats bearing GC. Levels of transferrin and free iron were determined by analysis of EPR spectra from computerized radiospectrometer EPR -RE-1307 at temperature of liquid nitrogen. Rate of superoxide radicals and nitric oxide generation in tumor and neutrophils of blood was determined by EPR using spin traps at room temperature. Content of ferritin in tumor homogenate and blood serum of rats with GC was determined by ELISA method using corresponding kits. Concentration of active forms of MMP-2 and -9 in obtained samples was determined using method of zymography., Results: Unregulated generation of superoxide radicals and NO by mitochondria of tumor cells and NADPH-oxidase and iNOS neutrophils via oxidation of iron-containing proteins causes the accumulation of "free iron" complexes in blood and tumor tissue of rats able to evoke oxide-induced damages of macromolecules. It has been shown that for resistant strain of carcinoma, as compared with sensitive one, significantly higher concentrations of active forms of MMP-2 and -9 in blood serum of rats are typical. Dynamics of gelatinases activity changes in tumor tissue corresponds in general with dynamics of changes in serum. In tumor tissue of rats the indices of gelatinases activity positively correlate with rate of superoxide radicals generation, content of "free iron" complexes, ferritin and activity of transferrin. Cytostatic agent increased levels of reactive oxygen species (ROS) and self-amplify rate of superoxide radicals generation. In turn, activation of MMPs via superoxide-depending regulation allows tumor cells to facilitate migration, invasion and finally - formation of metastatic centers. Mentioned above tumor "oxide phenotype" determines high level of its aggressiveness and forms corresponding level of drug resistance., Conclusions: Thus, high levels of superoxide radicals oxidize transport proteins and form free iron pool. Iron ions, via Haber - Weiss mechanism, initiate generation of the hydroxyl radicals, which also enhance oxidation processes.

Aim: To study in vivo the peculiarities of changes of iron metabolism and antioxidant system in dynamics of growth of Guerin carcinoma with different sensitivity to cisplatin., Materials and Methods: In order to evaluate the content of metallothionein-1 (MT-1) in tumor homogenates and blood serum of rats with cisplatin-sensitive and cisplatin-resistant Guerin carcinoma the immunoenzyme method was used. The evaluation of ceruloplasmin activity, content of "free iron" complexes, superoxide and NO-generating acti-vity of NADPH-oxidase and iNOS activity in neutrophils, blood serum and tumor homogenates was measured by EPR-spectro-scopy., Results: Maximal accumulation of MT-1 in blood serum and tumor, more pronounced in resistant strain, at the border of latent and exponential phase of growth has been shown that is the evidence of protective role of this protein in the respect to the generation of free radical compounds. It has been determined that in animals with cisplatin-resistant strain of Guerin carcinoma, increase of "free iron" complexes is more apparent both on the level of tumor and organism on the background on increase of CP/TR ratio that is the consequence of organism antioxidant protection system disorder., Conclutions: Mentioned changes in metabolism of iron with its accumulation in tumor and further reprogramming of mitochondria metabolism and activity of NADPH-oxidase for non-transformed cells are favorable conditions for the formation of oxidative phenotype of tumor.

Aim: The aim of our study is to investigate the disorders of ferritin functioning in breast cancer (BC) cells of different molecular subtype., Materials and Methods: The cell lines used in the analysis include T47D, MCF-7, MDA-MB-231, MDA-MB-468, MCF-10A, and 184A1. Ferritin heavy chains (FTH) expression was studied by immunohistochemical method. "Free iron" content and superoxide dismutase (SOD) activity were determined by means of EPR spectroscopy. Reactive oxygen species (ROS) level and peculiarities of microRNA expression in studied cell lines were evaluated using flow cytometry and PCR analysis, respectively., Results: It has been demonstrated that FTH expression directly correlates with proliferative activity of cells of both luminal (r = 0.51) and basal subtypes (r = 0.25), inversely correlates with expression of steroid hormones in cells of basal subtype (ER: r = -0.46; PR: r = -0.44) and does not depend on tumorigenic activity of both subtypes of studied cells (r = 0.12 and r = 0.9). Obtained data are the evidence that cells of luminal subtype B (MCF-7 cell line) and basal subtype (MDA-MB-231 and MDA-MB-468 cell lines) with high proliferative activity contain the highest level of free iron (2.9 ± 0.19·10(16)and 3.0 ± 0.22·10(16)) that can be consequence of intensive use of this element by cells, which actively divide and grow. Along with it, in cell of lines of basal subtype MDA-MB-231 and MDA-MB-468, high level of FTH (254 ± 2.3 and 270 ± 1.9) is being detected in consequence of increase of level of free iron, ROS (11.3 ± 1.05 and 7.27 ± 0.26) and SOD (9.4 ± 0.24 and 8.5 ± 0.18) as well as decrease of expression of microRNA 200b. In contrast, cells of luminal subtype B of MCF-7 line were distinguished by high expression of microRNA 200b and low ferritin level (125 ± 2.7)., Conclusion: Obtained data demonstrate that tumor cells, which are referred to different molecular subtypes, are characterized by changes in system of support of balance of intercellular iron and certain associations of studied factors.

To study the mechanism of interaction of tumor cells with bone marrow cells continuous wave electron paramagnetic resonance (EPR) experiments at 9 GHz including a spin trapping of superoxide were carried out. The common features of the EPR spectra in healthy and tumor affected tissues of donors and rats as well as their difference are presented and discussed. It is proposed that labile iron pool plays a significant role in mechanisms of tumor invasion. We hope that the observed EPR features could be used to study the mechanisms of invasion and progression of tumor in different organs.

It is known that inflammatory cytokines, which level is significantly increased in the pathogenesis of multiple sclerosis (MS), as well as interferon-beta, which is used to treat autoimmune diseases, can inhibit cytochrome P450-dependent processes of detoxification and biotransformation. The uncontrolled decrease of the activity of these processes may have a negative affect on the state of patients, so it is urgent to study the functional state of the cytochrome P450 system and to develop effective means for its regulation in these conditions. The effect of vitamin D3 and efficiency of its composition with vitamins B1, B2, B6, PP, E, alpha-lipoic, alpha-linolenoic acid and mineral substances (Mg, Zn, Se) in prevention of a functional state changes of cytochrome P450- and b5-dependent systems of the rat brain and liver endoplasmic reticulum at EAE are investigated. It has been shown that the essential decrease of the level of these cytochromes is observed both in the brain and liver. In addition the level of activity of NADH- and NADPH-oxidoreductases, which are part of microsomal electron transport chain components and coupled with monooxigenases, was reduced. These changes confirm the disturbances of a redox state and functional activity of detoxication and biotransformation systems in the studied animal tissues. Supplement of vitamin D3 as well as the composition of biologically active substances, which we developed earlier, effectively eliminated the decrease of the level of cytochromes and activities of NADH-oxidoreductase in immunised rat tissues. Normalization of these disturbances can be explained by antioxidant and membrane-stabilizing properties of applied substances, and also by the ability to reduce the activity of inflammatory reactions by regulation of the level of inflammatory cytokines in rat organism at EAE. Thus the studied vitamin-mineral composition appeared to be more effective to normalize the found disturbances and it can be useful for prevention of exacerbations and for improvement of a status of patients with multiple sclerosis and other diseases, which are accompanied with hyperactivation of immune system.

Aim: To estimate the impact of C(60) fullerene aqueous solution (C(60)FAS) on the rate of transplanted malignant tumor growth and metastasis., Methods: Lewis lung carcinoma was transplanted into С57Bl/6J male mice. Conventional methods for the evaluation of antitumor and antimetastatic effects have been used., Results: The C(60)FAS at low single therapeutic dose of 5 mg/kg inhibited the growth of transplanted malignant tumor (antitumor effect) and metastasis (antimetastatic effect): the maximum therapeutic effect was found to be of 76.5% for the tumor growth inhibition; the increase of animal life span by 22% was found; the metastasis inhibition index was estimated as 48%., Conclusion: It was found that water-soluble pristine С(60) fullerenes efficiently inhibit the transplanted malignant tumor growth and metastasis.

Growth experiments of transplanted malignant tumors in the presence of water-soluble C 60 fullerenes were performed on groups of mice. It was found that C 60 fullerenes efficiently inhibit the growth of transplanted malignant tumors. This behavior can be explained through their high antioxidant activity and the blocking of the specific cell receptors (for example, endothelial growth factor). The findings demonstrate the possibility of using C 60 fullerenes in anticancer therapy.

An increase of the intracellular reactive oxygen species (ROS) concentration leads to the development of oxidative stress and, thus, to the damage of cell components. The cause-and-effect relations between these processes have not been fully established yet. The ability of photo excited supramolecular composites containing fullerenes C60 immobilized at nanosilica particles to generate reactive oxygen species (ROS) in cells of two types (rat thymocytes, and transformed cells of ascite Erlich carcinoma, EAC, and leucosis L1210) is demonstrated. The damaging effect of photo excited C60-composites are shown, which appeared to be selective and manifested in transformed cells, but not in thymocytes. It has been shown that after the irradiation of aqueous solutions or cell suspensions in the presence of fullerene C60, the generation of reactive oxygen species is observed. It has been shown that the influence of photo excited fullerene C60 on metabolic processes depends on the composition of C60-containing complex and on the type of the cells. The damaging effects of photo excited fullerene C60-containing composites were demonstrated to be selective. The data presented suggest that the application of fullerene C60-containing composites for the selective activation of ROS-dependent death program in certain types of tumor cells is very promising.

Aim: To study the influence of redox-active cobalt(III) complex with tetradentate Schiff base and nicotinamide as an axial ligand on the rate of superoxide radical-anions generation and levels of NO in tumor and normal tissues of Lewis lung carcinoma bearing mice as well as activity of matrix metalloproteinases 2 and 9 (MMPs) in tumor., Methods: The superoxide radical-anions formation and NO level in tissues were assessed by EPR method with the use of 1-hydroxy-2,2,6,6-tetramethyl-4-oxopiperidin and diethyldithiocarbomate spin traps, respectively. MMPs activities were determined by zymography in polyacrylamide gel., Results: It was observed that the rate of superoxide radical-anions generation was selectively increased in tumor tissue (by a factor of 6-7) accompanied with the decrease of NO level (by a factor of 2) due to tested complex administration. Activities of MMPs in tumor were significantly decreased., Conclusion: It is supposed that the one of mechanisms of detected earlier antimetastatic effect of complex is based on its ability to induce the formation of high level of superoxide radical-anions selectively in the tumor tissue that results in the damage of its regulatory functions, in particular alteration in the regulation of NO-synthase, decrease of NO generation as well as activities of MMPs.

Aim: To study the relationship between the level of generation of reactive oxygen species (ROS) and nitric oxide (NO) and activity of matrix metalloproteinases (MMPs) MMP-2 and MMP-9 in the vessels isolated from rectal tumors and Arteria rectalis superior., Methods: EPR at the room temperature and 77 degrees K, Spin Traps technology and zymography in polyacrylamide gels were applied., Results: In the vessels isolated from rectal tumors and Arteria rectalis superior high levels of ROS, NO and formation of complexes of NO with FeS-proteins at the sites of electron-transporting chain of mitochondria have been detected. High activities of MMP-2 and MMP-9 in vascular wall were also observed. The direct positive correlation between the rate of NO generation and formation of complexes of NO with FeS-proteins as well as between ROS and NO formation and MMPs activities have been revealed., Conclusion: Altered oxidative equilibrium in mitochondria of cells in vascular wall promotes formation of cell hypoxia and its autocatalytic potentiation accompanied with activation of MMPs.

Biological effects of photoexcited in UV/VIS region water-soluble fullerenes C60 and synthesized C60-containing composites after its addition to cell incubation medium are studied. It is shown by EPR method, that in the presence of photoexcited C60 (10(-5) M) reactive oxygen species (ROS) are generated both in water solution and cell suspensions. ROS generation is accelerated if C60 is included into aminopropylaerosyl or antracenaliminopropylaerosyl. Photodynamic damage of Erlich ascites carcinoma cells by photoexcited C60-composites is confirmed by a decrease of cell viability, enhanced content of Schiff base fluorescent products of malonaldehyde as indicator of lipid peroxidation and the decrease in respiratory activity, estimated by MTT-test. No effects of photoexcited C60-composites were detected in thymocytes suspension. The data obtained testity to perspective utility of C60-composites for optimization of photodynamic therapy methods.

Aim: To study the effect of fullerene-containing composites, irradiated by visible light, on the radical oxygen species (ROS) generation in thymocytes, ascitic cells from Erlich's tumor and leukemia cells L1210; to investigate viability of these cells in the presence of fullerene-containing composites under irradiation conditions., Materials and Methods: The viability of cells was evaluated by staining with 0.4% solution of the trypan blue; ROS were detected with the use of electron paramagnetic resonance (EPR) spectroscopy and spin traps; solutions of fullerene-containing composites were irradiated with mercury-vapor lamp., Results: We demonstrated that under irradiation conditions fullerene-containing composites increase the rate of ROS generation and decrease the number of viable tumor cells., Conclusions: The obtained data allow to consider the fullerene-containing composites as potential agents for photodynamic therapy.

Aim: To establish the association between the radical oxygen species (ROS) and NO levels in the tumor cells mitochondria, between cell hypoxia development and activation of matrix metalloproteinases-2 and -9., Materials and Methods: Electron paramagnetic resonance (EPR) at room temperature and at the temperature of liquid nitrogen (77 degrees K), spin traps technology, enzymography in polyacrylamide gel were applied., Results: Redox-centers in the respiration cascade of mitochondria have been revealed, multiple oxidative damage of which in breast and liver cancer tissues of experimental animals as well as in tumor tissue from patients with gastric cancer promote the development of cell hypoxia. Involvement of ROS and NO in activation of latent forms of matrix metalloproteinases in gastric tumor tissues has been shown., Conclusion: We hypothesize that superoxide radical-anions participate in development of cell hypoxia in tumors and surrounding normal tissues inducing activation of latent forms of matrix metalloproteinases.

Targeting of mechanochemically activated doxorubicin (MA DOXO) nanoparticles, conventional doxorubicin, and electromagnetic irradiation (EMI) at A-549 lung carcinoma cells in vitro was investigated. Conventional DOXO was micronized using an input energy of 20 W/g for 5 min resulting in positively charged MA DOXO particles 10 times smaller than conventional DOXO. Mechanochemical activation gives rise to additional free quinone radicals. High performance liquid chromatograph analyses demonstrate that conventional and MA DOXO are quantitatively similar. Tumor cells were exposed to 40 MHz electromagnetic irradiation at a power density of 2 W/cm2. The lethal dose LD50 values of MA DOXO were 5 times greater than conventional doxorubicin. MA DOXO in combination with EMI at 37 degrees C demonstrates improved drug delivery to A-549 human lung carcinoma and greater cell kill than does conventional DOXO.

Aim: To study in vitro influence of mechanochemically activated (MA) doxorubicin (DOXO) and electromagnetic irradiation (EMI) on human lung carcinoma A-549 cells., Methods: Solid state DOXO was MA by input energy 20 W/g during 5 min. Tumor cells were exposed to 40 MHz EMI with power density 2 W/cm(2) at temperature 37 degrees C., Results: Particles of MA DOXO have sizes 10 time smaller than officinal DOXO, high performance liquid chromatography analysis showed that parameters of officinal and MA DOXO were quantitatively equal. Mechanochemical activation initiated in the drug formation of free radicals with g = 2.005, g = 2.003 and g = 1.97. LD(50) values of MA DOXO were 5 times lower than that of officinal drug. Cell survival decreased in the following way after effects EMI --> officinal DOXO --> MA DOXO --> officinal DOXO + EMI --> MA DOXO + EMI., Conclusion: Treatment by MA DOXO and drug with EMI at 37 degrees C showed better targeting of drug in human lung carcinoma A-549 cells outcomes than officinal DOXO.

Aim: To study the ability of fullerenes C(60) to catalyse the reactions of generation of reactive oxygen species (ROS) in water solution after photoexcitation and to affect the vitality of tumor cells in vitro., Methods: The number and vitality of cultured Ehrlich carcinoma cells or rat thymocytes were determined using tripane blue, ROS levels were registered using the methods of electron paramagnetic resonance (EPR) spectroscopy and spin traps, photoirradiation of water solution of fullerenes C(60) with visible light was carried out using mercury lamp., Results: Irradiation of water solution of fullerenes C(60) (10(-5) M) was accompanied with generation of ROS with the rate of 10 nMol/ml/min. After addition of irradiated C(60) solution to suspension of thymocytes or ascite cells, the decrease of the number of vital cells by 67 and 58%, respectively, has been registered., Conclusion: Photoirradiated water solutions of fullerenes C(60) may be potentially useful for photodynamic therapy of tumors as ROS catalytic system.

The review presents a complete analysis of studies on experimental and clinical application of platinum complexes with special reference to cis-dichlorodiamminoplatinum, both separately and in combination with other chemotherapeutic preparations. Platinum complexes show their highest antiblastic activity in treatment of ovarian, testicular, lung tumours and those located in the head and neck regions as well as of the bladder cancer and tumours of the other localizations resistant to the action of alkylating agents and other preparations. The clinical material is systematized so that it is possible on the basis of the analysis performed to choose an optimum regime for treating different tumours by platinum complexes.