Electron paramagnetic resonance study of tumor affected bone marrow

Redox state of adipose tissue for patients with gastric cancer and its connection with the body mass index and distance from the tumor

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.

Rectal Cancer: Redox State of Venous Blood and Tissues of Blood Vessels from Electron Paramagnetic Resonance and Its Correlation with the Five-Year Survival

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 (T2-4N0-2M0G2) 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.

Stomach Cancer: Interconnection between the Redox State, Activity of MMP-2, MMP-9 and Stage of Tumor Growth

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.

Changes in mitochondrial functioning with electromagnetic radiation of ultra high frequency as revealed by electron paramagnetic resonance methods

PURPOSE

To study the effects of electromagnetic radiation (EMR) of ultra high frequency (UHF) in the doses equivalent to the maximal permitted energy load for the staffs of the radar stations on the biochemical processes that occur in the cell organelles.

MATERIALS AND METHODS

Liver, cardiac and aorta tissues from the male rats exposed to non-thermal UHF EMR in pulsed and continuous modes were studied during 28 days after the irradiation by the electron paramagnetic resonance (EPR) methods including a spin trapping of superoxide radicals.

RESULTS

The qualitative and quantitative disturbances in electron transport chain (ETC) of mitochondria are registered. A formation of the iron-nitrosyl complexes of nitric oxide (NO) radicals with the iron-sulphide (FeS) proteins, the decreased activity of FeS-protein N2 of NADH-ubiquinone oxidoreductase complex and flavo-ubisemiquinone growth combined with the increased rates of superoxide production are obtained.

CONCLUSIONS

(i) Abnormalities in the mitochondrial ETC of liver and aorta cells are more pronounced for animals radiated in a pulsed mode; (ii) the alterations in the functioning of the mitochondrial ETC cause increase of superoxide radicals generation rate in all samples, formation of cellular hypoxia, and intensification of the oxide-initiated metabolic changes; and (iii) electron paramagnetic resonance methods could be used to track the qualitative and quantitative changes in the mitochondrial ETC caused by the UHF EMR.