Daily variations of plasma malondialdehyde levels in patients with early breast cancer

Redox and metabolic reprogramming in breast cancer and cancer-associated adipose tissue

Redox and metabolic processes are tightly coupled in both physiological and pathological conditions. In cancer, their integration occurs at multiple levels and is characterized by synchronized reprogramming both in the tumor tissue and its specific but heterogeneous microenvironment. In breast cancer, the principal microenvironment is the cancer-associated adipose tissue (CAAT). Understanding how the redox-metabolic reprogramming becomes coordinated in human breast cancer is imperative both for cancer prevention and for the establishment of new therapeutic approaches. This review aims to provide an overview of the current knowledge of the redox profiles and regulation of intermediary metabolism in breast cancer while considering the tumor and CAAT of breast cancer as a unique Warburg's pseudo-organ. As cancer is now recognized as a systemic metabolic disease, we have paid particular attention to the cell-specific redox-metabolic reprogramming and the roles of estrogen receptors and circadian rhythms, as well as their crosstalk in the development, growth, progression, and prognosis of breast cancer.

Atrial fibrillation in cancer, anticancer therapies, and underlying mechanisms

Atrial fibrillation (AF) is a common arrhythmic complication in cancer patients and can be exacerbated by traditional cytotoxic and targeted anticancer therapies. Increased incidence of AF in cancer patients is independent of confounding factors, including preexisting myocardial arrhythmogenic substrates, type of cancer, or cancer stage. Mechanistically, AF is characterized by fast unsynchronized atrial contractions with rapid ventricular response, which impairs ventricular filling and results in various symptoms such as fatigue, chest pain, and shortness of breath. Due to increased blood stasis, a consequence of both cancer and AF, concern for stroke increases in this patient population. To compound matters, cardiotoxic anticancer therapies themselves promote AF; thereby exacerbating AF morbidity and mortality in cancer patients. In this review, we examine the relationship between AF, cancer, and cardiotoxic anticancer therapies with a focus on the shared molecular and electrophysiological mechanisms linking these disease processes. We also explore the potential role of sodium-glucose co-transporter 2 inhibitors (SGLT2i) in the management of anticancer-therapy-induced AF.

Malondialdehyde-Induced Post-translational Modifications in Hemoglobin of Smokers by NanoLC-NSI/MS/MS Analysis

Malondialdehyde (MDA) is the most abundant α,β-unsaturated aldehyde generated from endogenous peroxidation of polyunsaturated fatty acids and is present in cigarette smoke. Post-translational modifications of blood hemoglobin can serve as biomarkers for exposure to chemicals. In this study, two types of MDA-induced modifications, the N-propenal and the dihydropyridine (DHP), were identified at multiple sites in human hemoglobin digest by the high-resolution mass spectrometry. The N-propenal and the DHP types of modification led to the increase of 54.0106 and 134.0368 amu, respectively, at the N-terminal and lysine residues. Among the 21 MDA-modified peptides, 14 with dose-response to MDA concentrations were simultaneously quantified in study subjects by the nanoflow liquid chromatography nanoelectrospray ionization tandem mass spectrometry under selected reaction monitoring (nanoLC-NSI-MS/MS-SRM) without prior enrichment. The results showed that the modifications of the N-propenal-type at α-Lys-11, α-Lys-16, α-Lys-61, β-Lys-8, and β-Lys-17, as well as the DHP-type at the α-N-terminal valine, are significantly higher in hemoglobin isolated from the blood of smokers than in nonsmoking individuals. This is the first report to identify and quantify multiple sites of MDA-induced modifications in human hemoglobin from peripheral blood. Our results suggest that the MDA-derived modifications on hemoglobin might represent valuable biomarkers for MDA-induced protein damage.

Renoprotective effects of dapagliflozin in an iron overload non-diabetic rat model

PURPOSE

Sodium glucose co-transporter (SGLT) 2 inhibitors are oral anti-diabetic drugs with proven kidney protective effects. Renal protective effects in non-diabetic individuals have also been shown in recent studies. The aim of this study was to determine the renal protective effects of dapagliflozin by evaluating the oxidative stress markers in the kidney tissue and demonstrating it in renal histological sections in an iron-overloaded rat model.

METHODS

A total of 24 Wistar Albino rats were separated into 3 groups of 8 rats. Iron sucrose (60 ​mg/kg/day) was administered intraperitoneally to the first group (Group Fe) (n ​= ​8), iron sucrose and dapagliflozin (0.1 ​mg/kg/day) to the second group (Group Fe ​+ ​D) (n ​= ​8) and intraperitoneal saline as placebo to the control group (Group C) (n ​= ​8) for 4 weeks. The glomerular changes were semi-quantitatively scored with Oxford Classification. Oxidative stress was analyzed from the tissue fluorescent oxidation product (FLOP), malondialdehyde (MDA) and total sulfhydryl (T-SH) levels.

RESULTS

Dapagliflozin prevented glomerular and mesangial damage of iron overload in the non-diabetic rat model. MDA levels were significantly higher in Group Fe compared to the Group C, and there was no significant difference between the Fe ​+ ​D group and Group C. T-SH levels were preserved in the Fe ​+ ​D group and were significantly higher than in the Fe group.

CONCLUSIONS

The results of this study showed that dapagliflozin helped preserve the glomerular and mesangial structure histologically and reduced oxidative stress markers in a non-diabetic iron overload rat model.

The correlation of antioxidant levels of breast cancer: A case controlled study

Many free radicles are implicated to activate a number of oncogenic signaling, cause damage to deoxyribonucleic acid and tumor suppressor genes, or promote expression of proto-oncogenes. Reduced level of antioxidants and increases oxidative stress markers are associated with the development of various types of cancer.This prospective study included 60 women who were grouped into equal groups. Patients group included 30 breast cancer women and control group consisting of 30 apparently healthy women. Both groups were compared regarding the serum levels of antioxidants biomarkers (vitamin C, ceruloplasmin, glutathione) and oxidative stress biomarkers, malondialdehyde (MDA), peroxynitrite, and gamma-glutamyl transferase.In regard to the antioxidant biomarkers, there was a significant difference between the patients and the controls regarding the levels of serum ceruloplasmin and glutathione, (P values .000) for each while vitamin C showed no significant correlation (P value .053), while regarding oxidative stress biomarkers, the correlation was significant for both peroxynitrite and MDA (P value .000 and .001) respectively, and not significant for gamma-glutamyl transferase (P value 1.00).Reduced level both ceruloplasmin and glutathione is seen in patients with breast cancer while vitamin C is not associated. Elevated levels of both peroxynitrite and MDA is seen in patients with breast cancer which may be used as serum markers for the early detection of breast cancer.

Metabolic reprogramming and disease progression in cancer patients

Genomics has contributed to the treatment of a fraction of cancer patients. However, there is a need to profile the proteins that define the phenotype of cancer and its pathogenesis. The reprogramming of metabolism is a major trait of the cancer phenotype with great potential for prognosis and targeted therapy. This review overviews the major changes reported in the steady-state levels of proteins of metabolism in primary carcinomas, paying attention to those enzymes that correlate with patients' survival. The upregulation of enzymes of glycolysis, pentose phosphate pathway, lipogenesis, glutaminolysis and the antioxidant defense is concurrent with the downregulation of mitochondrial proteins involved in oxidative phosphorylation, emphasizing the potential of mitochondrial metabolism as a promising therapeutic target in cancer. We stress that high-throughput quantitative expression profiling of differentially expressed proteins in large cohorts of carcinomas paired with normal tissues will accelerate translation of metabolism to a successful personalized medicine in cancer.

Determination of Melatonin Deprivation Impact on Sepsis With Acute Phase Reactants

BACKGROUND

The aim of the present study is to determine the association of melatonin hormone level on CRP, Total Antioxidant Status, Leukocyte, Procalcitonin, and Malondialdehyde, all acute phase reactants in the dark and light cycle of rats with sepsis model.

MATERIALS AND METHODS

In this study, 54 rats were divided into three groups. Whereas the first and third groups had a 12 h dark-light cycle, the second group was exposed to light for 24 h at 21°C-22°C for 10 d without any water and food restrictions. In the second and third groups, sepsis model was formed by cecal ligation and puncture (CLP) method at the end of 10th day, and blood samples were taken at the end of the 10th day. C-reactive protein, Malondialdehyde, Procalcitonin in the blood samples were analyzed by ELISA, and the levels of Total Antioxidant Status and leukocyte were determined by colorimetric method in the subsequent 12 and 24 h.

RESULTS

CRP values increased in the second group rats, which were kept continuously under light and had undergone CLP, from 288.8 mg/L to 584.0 mg/L at the end of the 12 h and the end of the 24 h, approximately, two times. In rats, which were kept under 12 h of light, 12 h of darkness, and applied CLP (group 3), these values increased from 416.9 to 619.1; an increase of 1.5 times. When assessed for MDA, it was determined that the differences between Group 2 and Group 3 were more prominent between 0 h and 12 h. While the MDA values in group 2 increased from 16.53 nmol/mL at the 12 h to 17.66 nmol/mL at the 24 h. However, MDA values did not yield statistically significant changes in the third group. Changes in the in PCT values were similar to the MDA values obtained. Increase coefficient of the PCT values between 0 h and 12 h in the second group 2 was 1.26; however, in the third group, it was negligible.

CONCLUSIONS

An increase in the oxidative stress was observed in the rats that underwent CLP and melatonin deprivation via continuous 24 h light exposure for 10 d. Accordingly, deprivation of light is considered to be effective in sepsis treatment due to the increase in melatonin levels in intensive care unit patients.

Oxidative stress in electrohypersensitivity self‑reporting patients: Results of a prospective in vivo investigation with comprehensive molecular analysis

A total of 32 electrohypersensitivity (EHS) self-reporting patients were serially included in the present prospective study for oxidative stress and antioxidative stress response assessment. All thiobarbituric acid-reactive substances (TBARs) were measured in the plasma, particularly malondialdehyde (MDA) for lipid peroxidation; additional measurements included total thiol group molecules, reduced glutathione (GSH), oxidized glutathione (GSSG) for oxidative stress assessment and nitrotyrosine, a marker of peroxynitrite-induced oxidative/nitrosative stress. In addition, the activity of Cu-Zn superoxide dismutase (SOD1) was measured in red blood cells (RBCs) and glutathione reductase (GR) and glutathione peroxidase (GPx) in RBCs and plasma. Depending of the biomarker considered, 30–50% of EHS self-reporting patients presented statistically significantly increased TBARs, MDA, GSSG and NTT mean plasmatic level values in comparison with normal values obtained in healthy controls (P<0.0001). By contrast, there were no plasmatic level values above the upper normal limits for GSH, GSH/GSSG ratio, total glutathione (GluT) and GSH/GluT ratio, and values for these GSH-associated biomarkers were statistically significantly decreased in 20–40% of the patients (P<0.0001). Furthermore, in RBCs, mean SOD1 and GPx activities were observed to be statistically significantly increased in ~60% and 19% (P<0.0001) of the patients, respectively, while increased GR activity in RBCs was observed in only 6% of the patients. The present study reports for the first time, to the best of our knowledge, that overall ~80% of EHS self-reporting patients present with one, two or three detectable oxidative stress biomarkers in their peripheral blood, meaning that these patients-as is the case for cancer, Alzheimer's disease or other pathological conditions-present with a true objective new pathological disorder.

Plasma fluorescent oxidation products and risk of estrogen receptor-negative breast cancer in the Nurses' Health Study and Nurses' Health Study II

Findings from epidemiologic studies of oxidative stress biomarkers and breast cancer have been mixed, although no studies have focused on estrogen receptor-negative (ER-) tumors which may be more strongly associated with oxidative stress. We examined prediagnostic plasma fluorescent oxidation products (FlOP), a global biomarker of oxidative stress, and risk of ER- breast cancer in a nested case-control study in the Nurses' Health Study and Nurses' Health Study II. ER- breast cancer cases (n = 355) were matched to 355 controls on age, month/time of day of blood collection, fasting status, menopausal status, and menopausal hormone use. Conditional logistic regression models were used to examine associations of plasma FlOP at three emission wavelengths (FlOP_360, FlOP_320, and FlOP_400) and risk of ER- breast cancer. We did not observe any significant associations between FlOP measures and risk of ER- breast cancer overall; the RRQ4vsQ1 (95 %CI) 0.70 (0.43-1.13), p trend = 0.09 for FlOP_360; 0.91(0.56-1.46), p trend = 0.93 for FlOP_320; and 0.62 (0.37-1.03), p trend = 0.10 for FlOP_400. Results were similar in models additionally adjusted for total carotenoid levels and in models stratified by age and total carotenoids. Although high (vs. low) levels of FIOP_360 and FIOP_400 were associated with lower risk of ER- breast cancer in lean women (body mass index (BMI) < 25 kg/m(2)) but not in overweight/obese women, these differences were not statistically significant (pint = 0.23 for FlOP_360; pint = 0.37 for FlOP_400). Our findings suggest that positive associations of plasma FlOP concentrations and ER- breast cancer risk are unlikely.

Oxidative stress and antioxidant parameters in neutropenic patients secondary to chemotherapy

OBJECTIVE

Neutropenia is a serious adverse event that necessitates dosage reduction in patients receiving chemotherapy. In this study, we evaluated the oxidative stress and antioxidant parameters in neutropenic patients after chemotherapy both during the neutropenic period and after successful treatment of neutropenia with filgrastim.

METHODS

We studied paraoxonase (PON1), arylesterase (ARE), malondialdehyde (MDA), high-density lipoprotein (HDL), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) in addition to routine biochemical and hematologic parameters. SPSS 12.0 was used for statistical evaluation of data (SPSS, Chicago, IL, USA).

RESULTS

In our study, PON1, HDL, and LDH levels during the period of active neutropenia were statistically significantly higher than these levels were after resolution of neutropenia (P<0.05); MDA and ALP levels were statistically significantly lower during the period of active neutropenia (P<0.05).

CONCLUSIONS

Overall, free oxygen radicals (FOR) were increased and antioxidant parameters were decreased with resolution of neutropenia. This is probably due to FOR produced by the increased number of neutrophils rather than tumor burden.

Plasma florescent oxidation products and breast cancer risk: repeated measures in the Nurses' Health Study

Reactive oxygen species (ROS), normally generated through biologic processes, may damage DNA, lipids, and proteins. ROS are balanced through enzymatic mechanisms and exogenous antioxidants; imbalance results in oxidative stress. Limited data suggest an association between oxidative stress and breast cancer. We evaluated pre-diagnostic plasma fluorescent oxidation products (FlOP), a global biomarker of oxidative stress, and breast cancer risk in a nested case-control study in the Nurses' Health Study. Participants provided two blood samples (1989-1990 and 2000-2002) (N = 18,743). 377 women developed breast cancer between the second collection and June 1, 2006. Cases were matched to 377 controls. Relative fluorescent intensity at three different excitation/emission wavelengths (FlOP_360, FlOP_320, FlOP_400) were quantified in both samples, providing distant (≥10 years before diagnosis) and proximate (≤6 years before diagnosis) measures of oxidative stress. We observed no association between FlOP and breast cancer risk in proximate or distant samples (e.g., proximate extreme quartiles: FlOP_360, RR 0.8, 95 % CI 0.5-1.3, p trend = 0.49; FlOP_320, RR 1.1, 95 % CI 0.7-1.7, p trend = 0.53; FlOP_400, RR 1.3, 95 % CI 0.8-2.0, p trend = 0.80). In general no association was observed when cross-classifying or averaging proximate and distant exposure (e.g., extreme quartile of averages: FlOP_360, OR 0.9, 95 % CI 0.6-1.4, p trend = 0.82; FlOP_400, OR 0.9, 95 % CI 0.6-1.4, p trend = 0.55), with the exception of a significant trend for average FlOP_320 (extreme quartiles, OR 1.6, 95 % CI 1.0-2.4, p trend = 0.02). We did not observe important associations between FlOP and breast cancer risk in this large prospective study, though our data suggest women with consistently high FlOP_320 may be at increased risk.

Superoxide dismutase isoenzyme activities in plasma and tissues of Iraqi patients with breast cancer

Breast cancer is the first of the most common ten cancers in Iraq. Its etiology is mulifactorial, oxidative stress and lipid peroxidation being suggested to play important roles in carcinogenesis. The purpose of this study was to investigate the oxidant-antioxidant status in breast cancer patients, by measuring SOD isoenzyme activities (total SOD, CuZn-SOD, Mn-SOD and EC-SOD) in plasma and breast tumors, and by estimating thiobarbituric reactive substance (TBRS) in tissue homogenates. General increase in total SOD activity was observed in plasma and tissue samples of breast tumors, greater in the malignant when compared to benign group (p<0.05). Mn- SOD showed a significant decrease in tissue malignant samples (p<0.05), and insignificant decrease in plasma malignant samples compared with control and benign samples. Plasma EC-SOD activity in both patient benign and malignant breast tumors demonstrated 3.5% and 22.8% increase, respectively. However, there was a decrease in tissue EC-SOD activity in malignant breast tumors when compared with benign. A similar tendency was noted for TBRS.We suggested that elevated total SOD might reflect a response to oxidative stress, and then may predict a state of excess reactive oxygen species in the carcinogenesis process. If there is proteolytic removal of the heparin binding domain, EC-SOD will lose its affinity for the extracellular matrix and diffuse out of the tissue. This will result in a decreased EC-SOD activity, thus leading to an increase in the steady-state concentration of O2- in this domain, and increase in EC-SOD activity in extracellular fluid. This might explain the result recorded here concerning the decrease in tissue EC-SOD activity and increase in plasma of breast cancer patients.

A review of recent studies on malondialdehyde as toxic molecule and biological marker of oxidative stress

AIM

Of the many biological targets of oxidative stress, lipids are the most involved class of biomolecules. Lipid oxidation gives rise to a number of secondary products. Malondialdehyde (MDA) is the principal and most studied product of polyunsaturated fatty acid peroxidation. This aldehyde is a highly toxic molecule and should be considered as more than just a marker of lipid peroxidation. Its interaction with DNA and proteins has often been referred to as potentially mutagenic and atherogenic. This review is intended to briefly describe the physiological origin of MDA, to highlight its toxicity, describe and comment on the most recent methods of detection and discuss its occurrence and significance in pathology.

DATA SYNTHESIS

In vivo origin as well as reactivity and consequent toxicity of MDA are reviewed. The most recent and improved procedures for the evaluation of MDA in biological fluids are described and discussed. The evidence of the occurrence of increased MDA levels in pathology is described.

CONCLUSIONS

In the assessment of MDA, the most common methods of detection are insufficiently sensitive and disturbed by interference coming from related species or overestimation derived from stressing analysis conditions. Moreover, no recent nutritional or medical trials report the use of one of the new and more reliable methods, some of which are undoubtedly accessible to virtually all the laboratories provided with a common HPLC or a spectrofluorimeter.