Oxidants and antioxidants in breast cancer

A rice SOUL family heme-binding protein REAC1 enhances the antioxidative capacity of C. elegans through modulation of ROS-related gene expression

The development and identification of beneficial components from crop resources are vital for individuals, especially the elderly, as they are capable of facilitating health. Red rice is widely consumed and possesses potential therapeutic effects to some extent, but it is important to discover the specific roles of each component when consumed purposefully. In this context, the REAC1/rHBP2, a red rice heme-binding protein (HBP) from the SOUL family, was revealed that possesses a role in boosting the antioxidative capacity of C. elegans that consume this protein. The Arabidopsis plants overexpressing REAC1 presented more tolerance to oxidative stress related to the wild-type plants. Furthermore, REAC1 derived from engineered bacteria exhibited clear activities of heme-binding and hydroxy radical inhibition in vitro. While no adverse effects were observed in the nematodes that were treated with REAC1, they exhibited enhanced motility and improved survival under oxidative conditions simulated by treatment with 5 mM H2O2 compared to the control group. Additionally, the levels of endogenous reactive oxygen species (ROS) were significantly reduced, and the expression of redox-related genes, such as SOD-3 and CAT-1, was evidently upregulated in the treated nematodes. Taken together, these results suggest that the red rice heme-binding protein REAC1 plays a critical role in the enhancement of the antioxidative capacity of C. elegans through ROS-related regulation, thereby offering a promising approach for individuals to combat oxidative stress.

Effect of H2O2 induced oxidative stress on volatile organic compounds in differentiated 3T3-L1 cells

Oxidative stress (OS) refers to the disruption in the balance between free radical generation and antioxidant defenses, leading to potential tissue damage. Reactive oxygen species (ROS) can interact with biological components, triggering processes like protein oxidation, lipid peroxidation, or DNA damage, resulting in the generation of several volatile organic compounds (VOCs). Recently, VOCs provided new insight into cellular metabolism and can serve as potential biomarkers. The objective is to investigate the impact of OS on cell metabolism by analyzing the release or alterations of VOCs in the headspace of differentiated 3T3-L1 adipocytes. An OS model in differentiated 3T3-L1 cell lines was constructed using hydrogen peroxide (H2O2) treatment. The effect of OS on cell metabolism was analyzed by detecting VOCs in the headspace of the cells using solid phase micro extraction (SPME) and gas chromatography-mass spectrometry (GCMS). Our findings indicate that H2O2 concentrations exceeding 300 µM induce significant OS, leading to adipocyte apoptosis, as evidenced by various assays. Of the twenty VOCs identified, ten were upregulated in the cells. VOCs such as diphenyl ether, 1,3,5-trioxane, 5-methyl tridecane, 2-ethyl-1-hexanol, and 2,4-di-tert-butyl phenol emerged as potential biomarkers for OS. This study demonstrates that elevated OS alters VOC profiles in differentiated 3T3-L1 adipocytes, providing insights into the effects of OS on adipose tissue and identifying potential OS biomarkers.

Role of Oxidative Stress in the Occurrence, Development, and Treatment of Breast Cancer

Breast cancer is one of the most prevalent cancers worldwide. Recent studies have increasingly emphasized the role of oxidative stress in the initiation and progression of breast cancer. This article reviews how oxidative stress imbalance influences the occurrence and advancement of breast cancer, elucidating the intricate mechanisms through which reactive oxygen species (ROS) operate in this context and their potential therapeutic applications. By highlighting these critical insights, this review aims to enhance our understanding of oxidative stress as a potential target for innovative therapeutic strategies in the management of breast cancer.

Pesticide exposure and oxidative stress generation are linked to poor prognosis outcomes in breast cancer women carrying the allelic variant rs7438135 in the UGT2B7 gene

Pesticide exposure is a risk factor for the development of several diseases, including breast cancer (BC). The enzyme UGT2B7 participate in detoxification of pesticides and the presence rs7438135 (G > A) variant in your gene increases its glucuronidation potential, contributing to oxidative stress metabolites neutralization. Here we investigated the impact of occupational pesticide exposure on the systemic oxidative stress generation from 228 women with BC depending on their UGT2B7 rs7438135 (G > A) status. q-PCR investigated the presence of the rs7438135 variant, and oxidative stress markers (lipid peroxidation levels, total antioxidant capacity-TRAP, and nitric oxide metabolites-NOx) were measured in plasma. Pesticide exposure induced significant augment in the systemic lipid peroxidation in the presence of the variant for several clinicopathological conditions, including tumors with high proliferation index (ki67) and with high aggressiveness. NOx was augmented in high ki67, positive progesterone receptors, high-grade and triple-negative/Luminal B tumors, and low-risk stratified patients. TRAP was depleted in young patients at menopause and those with triple-negative/Luminal B tumors, as well as those stratified as at low risk for death and recurrence. These findings showed that the presence of the variant was not able to protect from pesticide-induced oxidative stress generation in BC patients.

Polymorphic variants of the hOGG1, APEX1, XPD, SOD2, and CAT genes involved in DNA repair processes and antioxidant defense and their association with breast cancer risk

Breast cancer is one of the leading causes of mortality among women. The most frequently encountered tumors are luminal tumors. Associations of polymorphisms in the hOGG1 (rs1052133), APEX1 (rs1130409), XPD (rs13181), SOD2 (rs4880), and CAT (rs1001179) genes were studied in 313 nonsmoking postmenopausal patients with luminal B subtype breast cancer. The control group consisted of 233 healthy nonsmoking postmenopausal women. Statistically significant associations of the XPD and APEX1 gene polymorphisms with the risk of developing luminal B Her2-negative subtype of breast cancer were observed in a log-additive inheritance model, while the CAT gene polymorphism showed an association in a dominant inheritance model (OR = 1.41; CI 95 %: 1.08-1.85; Padj.= 0.011; OR = 1.39; CI 95 %: 1.07-1.81; Padj = 0.013 и OR = 1.70; CI 95 %: 1.19-2.43; Padj = 0.004, respectively). In the group of elderly women (aged 60-74 years), an association of the CAT gene polymorphism with the risk of developing luminal B subtype of breast cancer was found in a log-additive inheritance model (OR = 1.87; 95 % CI: 1.22-2.85; Padj = 0.0024). Using MDR analysis, the most optimal statistically significant 3-locus model of gene-gene interactions in the development of luminal B Her2-negative subtype breast cancer was found. MDR analysis also showed a close interaction and mutual enhancement of effects between the APEX1 and SOD2 loci and the independence of the effects of these loci from the CAT locus in the formation of luminal B subtype breast cancer.

Mechanism insights of curcumin and its analogues in cancer: An update

Cancer is the world's second leading cause of mortality and one of the major public health problems. Cancer incidence and mortality rates remain high despite the great advancements in existing therapeutic, diagnostic, and preventive approaches. Therefore, a quest for less toxic and more efficient anti-cancer strategies is still at the forefront of the current research. Traditionally important, curcumin commonly known as a wonder molecule has received considerable attention as an anti-cancer, anti-inflammatory, and antioxidant candidate. However, limited water solubility and low bioavailability restrict its extensive utility in different pathological states. The investigators are making consistent efforts to develop newer strategies to overcome its limitations by designing different analogues with better pharmacokinetic and pharmacodynamic properties. The present review highlights the recent updates on curcumin and its analogues with special emphasis on various mechanistic pathways involved in anti-cancer activity. In addition, the structure-activity relationship of curcumin analogues has also been precisely discussed. This article will also provide key information for the design and development of newer curcumin analogues with desired pharmacokinetic and pharmacodynamic profiles and will provide in depth understanding of molecular pathways involved in the anti-cancer activities.

Associated between Dietary Antioxidant Index (DAI) and Odds of Breast Cancer and Correlation between DAI with Pathobiological Markers: Hospital-Based Incidence Case-Control Study

Background: The relationship between dietary antioxidants and breast cancer (BrCa) has been investigated in various studies. As a limitation, they generally investigate the relationship between one specific antioxidant and the risk/odds of BrCa, and synergistic or inhibitory effects are less considered. Dietary antioxidant index (DAI) is a reliable nutritional tool that evaluates total nutritional antioxidant capacity and is validated with serum total antioxidant capacity (TAC) and Malondialdehyde (MDA). Our study aimed to investigate the association between the DAI and the odds of BrCa and the correlation between the DAI and pathobiological markers. We hypnotized a correlation between DAI and pathobiological markers, and there is an association between DAI and the odds of BrCa.Methods: Our study included 145 incidence cases of BrCa and 148 hospital-based controls. Controls were randomly selected from patients attending the same center and were frequency-matched on age (±10 years). DAI was calculated based on a valid semi-quantitative 168-item food frequency questionnaire data. DAI standardizes intake of major dietary antioxidants, including vitamins A, E, C, selenium, zinc, and magnesium, and presents them as summarized scores.Results: Modeling with multivariable regressions adjusting for major confounders including age, education, body mass index, occupation, alcohol, smoking, pregnancy, history of cancer, menarche age, metabolic equivalent of task, hormone replacement therapy, and total energy intake, there was a significant association between odds of BrCa and DAI (odds ratio = 0.18; 95% confidence interval:0.09-0.37; p-value= <0.01). After multiple controls, there was a significant and weak reverse correlation between DAI and the number of lymph node(s) (correlation coefficient= -.140; p-value = 0.05).Conclusion: Our study supports the hypothesis that dietary antioxidants intake is associated with a reduced odds of BrCa. Evidently, DAI can reveal these relationships better than a single study of antioxidants. However, further studies are needed to confirm or refute these results.

Redox Signaling Modulates Activity of Immune Checkpoint Inhibitors in Cancer Patients

Although immunotherapy is already a staple of cancer care, many patients may not benefit from these cutting-edge treatments. A crucial field of research now focuses on figuring out how to improve treatment efficacy and assess the resistance mechanisms underlying this uneven response. For a good response, immune-based treatments, in particular immune checkpoint inhibitors, rely on a strong infiltration of T cells into the tumour microenvironment. The severe metabolic environment that immune cells must endure can drastically reduce effector activity. These immune dysregulation-related tumour-mediated perturbations include oxidative stress, which can encourage lipid peroxidation, ER stress, and T regulatory cells dysfunction. In this review, we have made an effort to characterize the status of immunological checkpoints, the degree of oxidative stress, and the part that latter plays in determining the therapeutic impact of immunological check point inhibitors in different neoplastic diseases. In the second section of the review, we will make an effort to assess new therapeutic possibilities that, by affecting redox signalling, may modify the effectiveness of immunological treatment.

A Systematic Review and Meta-Analysis: Volatile Organic Compound Analysis in the Detection of Hepatobiliary and Pancreatic Cancers

BACKGROUND

Hepatobiliary cancers are notoriously difficult to detect, frequently leading to diagnosis in later stages of disease when curative treatment is not an option. The currently used biomarkers such as AFP (alpha-fetoprotein) and CA19.9 lack sensitivity and specificity. Hence, there is an unmet need for an alternative biomarker.

AIM

To evaluate the diagnostic accuracy of volatile organic compounds (VOCs) for the detection of hepatobiliary and pancreatic cancers.

METHODS

A systematic review of VOCs' use in the detection of hepatobiliary and pancreatic cancers was performed. A meta-analysis was performed using the software R. Heterogeneity was explored through meta-regression analysis.

RESULTS

A total of 18 studies looking at 2296 patients were evaluated. Pooled sensitivity and specificity of VOCs for the detection of hepatobiliary and pancreatic cancer were 0.79 (95% CI, 0.72-0.85) and 0.81 (97.5% CI, 0.76-0.85), respectively. The area under the curve was 0.86. Meta-regression analysis showed that the sample media used contributed to heterogeneity. Bile-based VOCs showed the highest precision values, although urine and breath are preferred for their feasibility.

CONCLUSIONS

Volatile organic compounds have the potential to be used as an adjunct tool to aid in the early diagnosis of hepatobiliary cancers.

Potential Role of Oxidative Stress in the Production of Volatile Organic Compounds in Obesity

Obesity is associated with numerous health issues such as sleep disorders, asthma, hepatic dysfunction, cancer, renal dysfunction, diabetes, cardiovascular complications, and infertility. Previous research has shown that the distribution of excess body fat, rather than excess body weight, determines obesity-related risk factors. It is widely accepted that abdominal fat is a serious risk factor for illnesses associated with obesity and the accumulation of visceral fat promotes the release of pro-oxidants, pro-inflammatory, and reactive oxygen species (ROS). The metabolic process in the human body produces several volatile organic compounds (VOCs) via urine, saliva, breath, blood, skin secretions, milk, and feces. Several studies have shown that VOCs are released by the interaction of ROS with underlying cellular components leading to increased protein oxidation, lipid peroxidation, or DNA damage. These VOCs released via oxidative stress in obese individuals may serves as a biomarker for obesity-related metabolic alterations and disease. In this review, we focus on the relationship between oxidative stress and VOCs in obesity.

Increasing importance of breast cancer in Nepal

Recently, breast cancer cases in Nepal are on the rise, accounting for approximately 16% of all cancer cases, making it the second most common malignancy. Given the dependence of the Nepalese on agriculture, the rampant use of pesticides as well as the presence of arsenic in water supplies might be contributing to this huge rise in cancer cases. Herein, we provide a brief overview of the status of breast cancer, its burden, risk factors, screening and modes of treatment in Nepal.

Dihydropyrazole-Carbohydrazide Derivatives with Dual Activity as Antioxidant and Anti-Proliferative Drugs on Breast Cancer Targeting the HDAC6

Breast cancer (BC) is the most frequently diagnosed cancer and is the second-most common cause of death in women worldwide. Because of this, the search for new drugs and targeted therapy to treat BC is an urgent and global need. Histone deacetylase 6 (HDAC6) is a promising anti-BC drug target associated with its development and progression. In the present work, the design and synthesis of a new family of dihydropyrazole-carbohydrazide derivatives (DPCH) derivatives focused on HDAC6 inhibitory activity is presented. Computational chemistry approaches were employed to rationalize the design and evaluate their physicochemical and toxic-biological properties. The new family of nine DPCH was synthesized and characterized. Compounds exhibited optimal physicochemical and toxicobiological properties for potential application as drugs to be used in humans. The in silico studies showed that compounds with –Br, –Cl, and –OH substituents had good affinity with the catalytic domain 2 of HDAC6 like the reference compounds. Nine DPCH derivatives were assayed on MCF-7 and MDA-MB-231 BC cell lines, showing antiproliferative activity with IC₅₀ at μM range. Compound 2b showed, in vitro, an IC₅₀ value of 12 ± 3 µM on human HDAC6. The antioxidant activity of DPCH derivatives showed that all the compounds exhibit antioxidant activity similar to that of ascorbic acid. In conclusion, the DPCH derivatives are promising drugs with therapeutic potential for the epigenetic treatment of BC, with low cytotoxicity towards healthy cells and important antioxidant activity.

Impact of Physical Activity on Oxidative Stress Markers in Patients with Metastatic Breast Cancer

Purpose

Regular physical activity (PA) can affect oxidative stress, known to be involved in carcinogenesis. The objective of this study was to evaluate the associations between a six-month PA intervention and oxidative stress biomarkers, PA, and clinical outcomes in patients with metastatic breast cancer.

Methods

Forty-nine newly diagnosed patients with metastatic breast cancer were recruited for a single-arm, unsupervised, and personalized six-month walking intervention with activity tracker. PA level and PA fitness, plasma concentrations of DNA oxidation (8OhdG), lipid peroxidation (MDA), and protein oxidation (AOPP), plasma activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase, plasma and leucocyte activities of myeloperoxidase (MPO) and NADPH oxidase (NOX), and clinical markers of tumor progression (RECIST criteria) were measured at baseline and after the six-month intervention.

Results

GPX activity (+17%) and MDA (+9%) significantly increased between baseline and the end of the intervention. Changes in PA level and fitness were significantly positively correlated with changes in plasma GPX and significantly negatively with changes in NOX in the leucocytes. Plasma MDA was significantly higher (+20%) whereas plasma AOPP was lower (-46%) for patients with tumor progression or that died during the six months as compared to patients without progression.

Conclusion

A six-month PA intervention may be potentially beneficial in metastatic breast cancer patients for enhancing antioxidant enzyme activity and decreasing prooxidant enzyme activity. Moreover, AOPP and MDA could also be favorable and unfavorable biomarkers, respectively, since they are associated with disease progression and fitness level in this population. This trial is registered with NCT number: NCT03148886.

Antioxidants for the Treatment of Breast Cancer: Are We There Yet?

Breast cancer is the most frequent cancer and the leading cause of cancer death in women. Oxidative stress and the generation of reactive oxygen species (ROS) have been related to cancer progression. Compared to their normal counterparts, tumor cells show higher ROS levels and tight regulation of REDOX homeostasis to maintain a low degree of oxidative stress. Traditionally antioxidants have been extensively investigated to counteract breast carcinogenesis and tumor progression as chemopreventive agents; however, there is growing evidence indicating their potential as adjuvants for the treatment of breast cancer. Aimed to elucidate whether antioxidants could be a reality in the management of breast cancer patients, this review focuses on the latest investigations regarding the ambivalent role of antioxidants in the development of breast cancer, with special attention to the results derived from clinical trials, as well as their potential use as plausible agents in combination therapy and their power to ameliorate the side effects attributed to standard therapeutics. Data retrieved herein suggest that antioxidants play an important role in breast cancer prevention and the improvement of therapeutic efficacy; nevertheless, appropriate patient stratification based on "redoxidomics" or tumor subtype is mandatory in order to define the dosage for future standardized and personalized treatments of patients.

Reduced Expression of GPX3 in Breast Cancer Patients in Correlation with Clinical Significance

Glutathione peroxidase 3 (GPX3) is the main antioxidant enzyme in plasma. Its biological roles are to protect cells from oxidative stress-induced damage. Several studies have been reported the association between GPX3 expression and its correlation with cancer carcinogenesis including breast cancer. The aim of this research was to investigate the GPX3 messenger ribonucleic acid (mRNA) expression in 82 breast tumors and paired normal breast tissues by SYBR green quantitative real-time reverse transcription-polymerase chain reaction and the association with clinicopathological data. Our results show that GPX3 reduced expression was found significantly associated with number of metastatic lymph nodes (odds ratio [OR] = 3.41, 95% confidence interval [CI] = 1.35–8.64, p  = 0.01), no distant metastasis (OR = 5.52, 95% CI = 3.74–11.89, p  = 0.04), and nonhormone usage breast cancer patients (OR = 0.19, 95% CI = 0.04–0.93, p  = 0.04). This finding suggested that GPX3 plays a role in breast carcinogenesis, and might serve as a prognostic biomarker in breast cancer patients.

Uric Acid Mediated the Association Between BMI and Postmenopausal Breast Cancer Incidence: A Bidirectional Mendelian Randomization Analysis and Prospective Cohort Study

BACKGROUND

Observational epidemiological studies have reported the associations of high body mass index (BMI) with elevated serum uric acid (UA) level and increased risk of postmenopausal breast cancer. However, whether UA is causally induced by BMI and functioned in the BMI-breast cancer relationship remains unclear.

METHODS

To elucidate the causality direction between BMI and serum UA, the bidirectional Mendelian randomization (MR) analyses were performed by using summarized data from the largest Asian genome-wide association studies (GWAS) of BMI and UA carried out in over 150,000 Japanese populations. Then, a total of 19,518 postmenopausal women from the Dongfeng-Tongji (DFTJ) cohort (with a mean 8.2-year follow-up) were included and analyzed on the associations of BMI and serum UA with incidence risk of postmenopausal breast cancer by using multivariable Cox proportional hazard regression models. Mediation analysis was further conducted among DFTJ cohort to assess the intermediate role of serum UA in the BMI-breast cancer association.

RESULTS

In the bidirectional MR analyses, we observed that genetically determined BMI was causally associated with elevated serum UA [β(95% CI) = 0.225(0.111, 0.339), p < 0.001], but not vice versa. In the DFTJ cohort, each standard deviation (SD) increment in BMI (3.5 kg/m²) and UA (75.4 μmol/l) was associated with a separate 24% and 22% increased risk of postmenopausal breast cancer [HR(95% CI) = 1.24(1.07, 1.44) and 1.22(1.05, 1.42), respectively]. More importantly, serum UA could mediate 16.9% of the association between BMI and incident postmenopausal breast cancer.

CONCLUSIONS

The current findings revealed a causal effect of BMI on increasing serum UA and highlighted the mediating role of UA in the BMI-breast cancer relationship. Controlling the serum level of UA among overweight postmenopausal women may help to decrease their incident risk of breast cancer.

Evaluation of the Diagnostic and Predicative Values of 8-Iso-Prostaglandin F2α as a Biomarker of Breast Cancer

BACKGROUND

Breast cancer (BC) is a commonly reported cancer that is widely prevalent among women. Its early detection improves patient survival and results in better outcomes. For diagnosis and follow-up care, tumor markers are one of the feasible investigations to be ordered. 8-Iso-prostaglandin F2α (8-iso-PGF2α) serves as a serum marker reflecting oxidative stress and subsequent damaging of DNA. In the present study, we aimed to evaluate both diagnostic and predictive values of 8-iso-PGF2α in BC patients.

MATERIALS AND METHODS

Serum levels of 8-iso-PGF2α were assessed for 66 women with benign breast tumors and 65 women who had malignant BC. To compare the patients who had breast tumors with healthy individuals, 63 women free of breast diseases were selected as controls.

RESULTS

The serum level of 8-iso-PGF2α in the BC patients (57.92 pg/mL) was significantly higher compared to those with benign tumors (18.89 pg/mL) (p < 0.001). In addition, individuals with no breast diseases had less 8-iso-PGF2α (4.02 pg/mL) compared to those who had developed a tumor (p < 0.001). Serum 8-iso-PGF2α was found to be positively correlated with both carcinoembryonic antigen (r = 0.74, p < 0.001) and cancer antigen 15-3 (r = 0.80, p < 0.001). Furthermore, serum 8-iso-PGF2α showed high diagnostic performance in BC (AUC = 0.999, sensitivity = 100%, specificity = 99.2% at a cutoff value of 36.18 pg/mL).

CONCLUSIONS

Our study found that the high level of serum 8-iso-PGF2α helps to provide a non-invasive indicator to detect BC. Future work with a larger sample size and various phases of BC can confirm the current results which provide insights into the early detection of cancer.

Emerging non-invasive detection methodologies for lung cancer

The potential for non-invasive lung cancer (LC) diagnosis based on molecular, cellular and volatile biomarkers has been attracting increasing attention, with the development of advanced techniques and methodologies. It is standard practice to tailor the treatments of LC for certain specific genetic alterations, including the epidermal growth factor receptor, anaplastic lymphoma kinase and BRAF genes. Despite these advances, little is known about the internal mechanisms of different types of biomarkers and the involvement of their related biochemical pathways during the development of LC. The development of faster and more effective techniques is essential for the identification of different biomarkers. The present review summarizes some of the latest methods used for detecting molecular, cellular and volatile biomarkers in LC and their potential use in clinical diagnosis and targeted therapy.

Therapeutic cooperation between auranofin, a thioredoxin reductase inhibitor and anti-PD-L1 antibody for treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBCs) is a very aggressive and lethal form of breast cancer with no effective targeted therapy. Neoadjuvant chemotherapies and radiotherapy remains a mainstay of treatment with only 25-30% of TNBC patients responding. Thus, there is an unmet clinical need to develop novel therapeutic strategies for TNBCs. TNBC cells have increased intracellular oxidative stress and suppressed glutathione, a major antioxidant system, but still, are protected against higher oxidative stress. We screened a panel of antioxidant genes using the TCGA and METABRIC databases and found that expression of the thioredoxin pathway genes is significantly upregulated in TNBC patients compared to non-TNBC patients and is correlated with adverse survival outcomes. Treatment with auranofin (AF), an FDA-approved thioredoxin reductase inhibitor caused specific cell death and impaired the growth of TNBC cells grown as spheroids. Furthermore, AF treatment exerted a significant in vivo antitumor activity in multiple TNBC models including the syngeneic 4T1.2 model, MDA-MB-231 xenograft and patient-derived tumor xenograft by inhibiting thioredoxin redox activity. We, for the first time, showed that AF increased CD8^+Ve T-cell tumor infiltration in vivo and upregulated immune checkpoint PD-L1 expression in an ERK1/2-MYC-dependent manner. Moreover, combination of AF with anti-PD-L1 antibody synergistically impaired the growth of 4T1.2 primary tumors. Our data provide a novel therapeutic strategy using AF in combination with anti-PD-L1 antibody that warrants further clinical investigation for TNBC patients.

No evidence for a major effect of three common polymorphisms of the GPx1, MnSOD, and CAT genes on PCOS susceptibility

AIM

Polycystic ovary syndrome (PCOS) is one of the prevalent endocrine-metabolic disorders. It is proposed that oxidative stress contributes to PCOS susceptibility and its metabolic associations. The current study aimed to investigate the influence of GPx1 (rs1050450), MnSOD (rs4880), and Catalase (rs1001179) variants with PCOS susceptibility, for the first time.

METHODS

In a case-control study, 350 Kurdish female volunteers (175 PCOS patients and 175 healthy controls) from Western Iran were studied. Genotyping for GPx1 and MnSOD were done using PCR-RFLP and for CAT the allele-specific PCR method was used.

RESULTS

The percentage of patients suffering from hirsutism, acne, and acanthosis among patients with PCOS were 44.6%, 30.3%, and 14.9%, respectively. Distribution of alleles among patients suffering from PCOS versus healthy women was 'Pro' (69.1% vs 68.8%) and 'Leu' (31.4% vs 31.2%) for Gpx1, 'Ala' (61.43% vs 56.57%) and 'Val' (38.57% vs 43.43%) for MnSOD, and 'C' (83.43% vs 84.57%) and 'T' (16.57% vs 15.43%) for CAT.

CONCLUSION

GPx1 (rs1050450), MnSOD (rs4880), and CAT (rs1001179) variants might not be a risk factor for PCOS.

Bioactivities of EF24, a Novel Curcumin Analog: A Review

Curcumin is an attractive agent due to its multiple bioactivities. However, the low oral bioavailability and efficacy profile hinders its clinical application. To improve the bioavailability, many analogs of curcumin have been developed, among which EF24 is an excellent representative. EF24 has enhanced bioavailability over curcumin and shows more potent bioactivity, including anti-cancer, anti-inflammatory, and anti-bacterial. EF24 inhibits tumor growth by inducing cell cycle arrest and apoptosis, mainly through its inhibitory effect on the nuclear factor kappa B (NF-κB) pathway and by regulating key genes through microRNA (miRNA) or the proteosomal pathway. Based on the current structure, more potent EF24 analogs have been designed and synthesized. However, some roles of EF24 remain unclear, such as whether it induces or inhibits reactive oxygen species (ROS) production and whether it stimulates or inhibits the mitogen activated kinase-like protein (MAPK) pathway. This review summarizes the known biological and pharmacological activities and mechanisms of action of EF24.

The Impact of Antioxidants from the Diet on Breast Cancer Cells Monitored by Raman Microspectroscopy

Background:

The impact of the ubiquitous dietary phenolic compound p-coumaric acid on human breast cancer cells was assessed, through a multidisciplinary approach: Combined biological assays for cytotoxicity evaluation and biochemical profiling by Raman microspectroscopic analysis in cells. </P><P> Methods: Para-coumaric acid was shown to exert in vitro chemoprotective and antitumor activities, depending on the concentration and cell line probed: a significant anti-invasive ability was detected for the triple-negative MDA-MB-231 cells, while a high pro-oxidant effect was found for the estrogen- dependent MCF-7 cells. A striking cell selectivity was obtained, with a more noticeable outcome on the triple-negative MDA-MB-231 cell line.

Results:

The main impact on the cellular biochemical profile was verified to be on proteins and lipids, thus justifying the compound´s anti-invasive effect and chemoprotective ability.

Conclusion:

p-Coumaric acid was thus shown to be a promising chemoprotective/chemotherapeutic agent, particularly against the low prognosis triple-negative human breast adenocarcinoma.

Exhaled breath analysis for gastric cancer diagnosis in Colombian patients

We present here the first study that directly correlates gastric cancer (GC) with specific biomarkers in the exhaled breath composition on a South American population, which registers one of the highest global incidence rates of gastric affections. Moreover, we demonstrate a novel solid state sensor that predicts correct GC diagnosis with 97% accuracy. Alveolar breath samples of 30 volunteers (patients diagnosed with gastric cancer and a controls group formed of patients diagnosed with other gastric diseases) were collected and analyzed by gas-chromatography/mass-spectrometry (GC-MS) and with an innovative chemical gas sensor based on gold nanoparticles (AuNP) functionalized with octadecylamine ligands. Our GC-MS analyses identified 6 volatile organic compounds that showed statistically significant differences between the cancer patients and the controls group. These compounds were different from those identified in previous studied performed on other populations with high incidence rates of this malady, such as China (representative for Eastern Asia region) and Latvia (representative for Baltic States), attributable to lifestyle, alimentation and genetics differences. A classification model based on principal component analysis of our sensor data responses to the breath samples yielded 97% accuracy, 100% sensitivity and 93% specificity. Our results suggest a new and non-intrusive methodology for early diagnosis of gastric cancer that may be deployed in regions lacking well-developed health care systems as a prediagnosis test for selecting the patients that should undergo deeper investigations (e.g., endoscopy and biopsy).

Oxidative stress in female cancers

Breast, cervical and ovarian cancers are highly prevalent in women worldwide. Environmental, hormonal and viral-related factors are especially relevant in the development of these tumors. These factors are strongly related to oxidative stress (OS) through the generation of reactive oxygen species (ROS). The OS is caused by an imbalance in the redox status of the organism and is literally defined as "an imbalance between ROS generation and its detoxification by biological system leading to impairment of damage repair by cell/tissue". The multistep progression of cancer suggests that OS is involved in cancer initiation, promotion and progression. In this review, we described the role of OS and the interplay with environmental, host and viral factors related to breast, cervical and ovarian cancers initiation, promotion and progression. In addition, the role of the natural antioxidant compound curcumin and other compounds for breast, cervical and ovarian cancers prevention/treatment is discussed.

MCUR1-Mediated Mitochondrial Calcium Signaling Facilitates Cell Survival of Hepatocellular Carcinoma via Reactive Oxygen Species-Dependent P53 Degradation

AIMS

Levels of the mitochondrial calcium uniporter regulator 1 (MCUR1) increases during development of hepatocellular carcinoma (HCC). However, mechanisms of how mitochondrial Ca²⁺ homeostasis is modulated and its function remain limited in cancers.

RESULTS

MCUR1 was frequently upregulated in HCC cells to enhance the Ca²⁺ uptake into mitochondria in an MCU-dependent manner, which significantly facilitated cell survival by inhibiting mitochondria-dependent intrinsic apoptosis and promoting proliferation of HCC cells, and thus led to poor prognosis. In vivo assay confirmed these results, indicating that overexpressed MCUR1 notably decreased the fraction of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells and increased the positive Ki67 staining in xenograft tumors, while reduced MCUR1 expression was associated with impaired growth capacity of HCC cells in nude mice. The survival advantage conferred by MCUR1-mediated mitochondrial Ca²⁺ uptake was majorly caused by elevated production of mitochondrial reactive oxygen species and subsequent AKT/MDM2- induced P53 degradation, which regulated the expression level of apoptosis-related molecules and cell cycle-related molecules. Treatment of mitochondrial Ca²⁺-buffering protein parvalbumin remarkably inhibited the growth of HCC cells. Conclusions and Innovation: Our study provides evidence supporting a possible tumor-promoting role for MCUR1-mediated mitochondrial Ca²⁺ uptake and uncovers a mechanistic understanding that links change of mitochondrial Ca²⁺ homeostasis to cancer cell survival, which suggests a potential novel therapeutic target for HCC. Antioxid. Redox Signal. 28, 1120-1136.

Reactive Oxygen Species-Mediated Autophagy Defines the Fate of Cancer Stem Cells

Significance: A fraction of tumorigenic cells, also known as tumor initiating or cancer stem cells (CSCs), is thought to drive tumor growth, metastasis, and chemoresistance. However, little is known regarding mechanisms that convey relevant pathways contributing to their self-renewal, proliferation, and differentiation abilities. Recent Advances: Recent works on CSCs provide evidence on the role of redox disruption and regulation of autophagic flux. This has been linked to increased DNA repair capacity and chemoresistance. Critical Issues: The current review summarizes the most recent studies assessing the role of redox homeostasis, autophagy, and chemoresistance in CSCs, including some novel findings on microRNAs and their role in horizontal transfer within cancer cell populations. Future Directions: Rational anticancer therapy and prevention should rely on the fact that cancer is a redox disease with the CSCs being the apex modulated by redox-mediated autophagy. Antioxid. Redox Signal. 28, 1066-1079.

The effect of catalase C262T gene polymorphism in susceptibility to ovarian cancer in Kermanshah province, Western Iran

Ovarian cancer has a heterogeneous biology and behaviour. Oxidative stress can initiate chronic inflammation, which can sequentially facilitate chronic diseases, including cancer. Oxidative stress may arise when there is extra reactive oxygen species (ROS) production and/or inadequate defence mechanisms. There are some antioxidant defences that can fight against oxidative damage, including catalase (CAT) enzyme. We sought to evaluate the association of CAT C262T gene polymorphism with increased risk of ovarian cancer. A total of 74 paraffin-embedded ovarian cancer blocks were taken from the archive of Imam-Reza Hospital, Kermanshah University of Medical Sciences, between 2010 and 2014. Also, 153 blood samples were harvested from healthy volunteers. For genotyping of CAT C262T, we designed allele-specific polymerase chain reaction (AS-PCR). 'T' allele of CAT C262T showed a protective effect against the risk of ovarian cancer [OR = 0.4 (95% CI 0.25-0.6), p value <.001]. Calculating adjusted odds ratio showed the distribution of alleles and genotypes was not affected by age. The present study reported a significant association between the distribution of CAT C262T gene polymorphism and ovarian cancer for the first time in a sample of the Iranian population. Impact Statement What is already known on this subject: Ovarian cancer has a heterogeneous biology and behaviour at the clinical, cellular and molecular aspects. Ovulation releases follicular fluid containing reactive oxygen species which is related to changes in the microenvironment, such as inflammation, that could be a factor in early ovarian carcinogenesis. There are some antioxidant defences that can protect cells against oxidative damage, including catalase (CAT). Different studies investigated the relationships between CAT C262T polymorphism and several diseases. Belotte et al. ( 2015 ), for the first time, indicated no significant association between CAT C262T and the risk of ovarian cancer, while they showed this SNP is associated with poor survival and therefore may serve as a prognostic factor for ovarian cancer. What the results of this study add: In the present study, 'T' allele of CAT C262T showed a protective effect against the risk of ovarian cancer. Calculating adjusted odds ratio showed that the distribution of alleles and genotypes is not affected by age. What the implications are of these findings for clinical practice and/or further research: Pair-wise genetic analyses using SNPSTATS software showed that this genotyping was more compatible with recessive models, i.e. two copies of the associated variant are required to increase the risk of ovarian cancer. Further research about other antioxidant genes in a larger population is needed to predict the risk of ovarian cancer and survival rate of patients.

Peroxiredoxin 1 expression in active ulcerative colitis mucosa identified by proteome analysis and involvement of thioredoxin based on immunohistochemistry

Ulcerative colitis (UC) is a chronic, relapsing, inflammatory bowel disease, and patients with long-standing UC are at high risk of developing colorectal cancer as a typical case of the organ-specific chronic inflammation-carcinoma sequence. Interactions between epithelial and stromal cells and alterations in a variety of stromal microenvironments have been demonstrated to have important roles in the carcinogenesis of UC-associated carcinoma. Therefore, the identification of proteins in the inflammatory microenvironment is important not only in the epithelium, however also in the stroma of UC inflammatory foci. To identify proteins associated with UC-associated carcinoma, the present study used proteomic analysis with two-dimensional electrophoresis and mass spectrometry. Differentially expressed proteins were assessed between active and inactive UC biopsy specimens. Results were verified by immunohistochemistry. Peroxiredoxin 1 (PRDX1) was among the proteins identified to have increased expression in active compared with inactive UC. Immunohistochemical analysis indicated that the expression of both PRDX1 and thioredoxin (TRX) increased with increasing inflammation grade in epithelial cells in UC mucosal crypts. PRDX1-positive stromal cells in the lower half of the lamina propria increased along with colitis severity. Furthermore, the expression of both PRDX1 and TRX proteins was increased in UC-associated neoplastic lesions compared with normal mucosa. A stepwise increase in PRDX1 expression was clear with increasing tumor progression in UC-associated tumorigenesis. Since PRDX1 and TRX overexpression was a unique characteristic of UC activity and UC-associated neoplastic lesions, PRDX1 and TRX expression may reflect oxidative stress along with the severity of colitis activity and UC-associated tumorigenesis in patients with UC.

Selenium and Cancer Stem Cells

Selenium (Se) is an essential micronutrient that functions as "redox gatekeeper" and homeostasis factor of normal and cancer cells. Epidemiology and experimental studies, in the last years suggested that both inorganic and organic forms of Se may have favorable health effects. In this regard, a protective action of Se on cellular systems that may help preventing cancer cell differentiation has been demonstrated, while the hypothesis that Se compounds may cure cancer and its metastatic diffusion appears speculative and is still a matter of investigation. Indeed, the overall actions of Se compounds in carcinogenesis are controversial. The recognition that cancer is a stem cell disease instigated major paradigm shifts in our basic understanding of cancer and attracted a great deal of interest. Although current treatment approaches in cancer are grounded in the need to kill the majority of cancer cells, targeting cancer stem cells (CSCs) may hold great potential in improving cancer treatment. In this respect, Se compounds have been demonstrated modulating numerous signaling pathways involved in CSC biology and these findings are now stimulating further research on optimal Se concentrations, most effective and cancer-specific Se compounds, and inherent pathways involved in redox and metabolic regulation of CSCs. In this review, we summarize the current knowledge about the effects of Se compounds on CSCs, by focusing on redox-dependent pathways and main gene regulation checkpoints that affect self-renewal, differentiation, and migration responses in this subpopulation of cancer cells.

Role of Sex Hormones in the Control of Vegetative and Metabolic Functions of Middle-Aged Women

Aims: In women's life, menopause is characterized by significant physiological changes often associated with an increase in body mass and obesity-associated sicknesses. Numerous researches described interdependencies of estrogen deficiency, aging, and resting energy expenditure (REE) downfall in the obesity correlated with the menopause. The aim of this study was to determining whether healthy, obese menopausal women underwent HRT treatment, showed changes in their REE, autonomic asset, and assessment of oxidative stress in comparison with obese pre- and post-menopausal women.

Methodology: In this study, we measured the body composition, the REE, the oxidative stress, the diet assimilation, and the autonomic nervous system activity in three groups: pre-menopause women (n = 50), post-menopause women following hormone-replacement therapy (HRT; n = 50), and post-menopause women not following HRT (n = 50).

Results: In the group with HRT a significant increase of the sympathetic activity and REE was described. Finally this group showed a notable increment of oxidative stress compared with the others, and utilizing BIA instrument, the free fat mass was increased respect to the fat mass of obese women.

Conclusion: The study highlights the importance of the HRT-related physiological changes that influence body weight in menopause women. This results are important because have a practical implications for prevention and/or treatment of the obesity.

Downregulation of SAFB Sustains the NF-B Pathway by Targeting TAK1 during the Progression of Colorectal Cancer

Purpose: To investigate the role and the underlying mechanism of scaffold attachment factor B (SAFB) in the progression of colorectal cancer (CRC).Experimental Design: SAFB expression was analyzed in the Cancer Outlier Profile Analysis of Oncomine and in 175 paraffin-embedded archived CRC tissues. Gene Ontology analyses were performed to explore the mechanism of SAFB in CRC progression. Western blot, RT-PCR, luciferase assay, and chromatin immunoprecipitation (ChIP) were used to detect the regulation of transforming growth factor-β-activated kinase 1 (TAK1) and NF-κB signaling by SAFB The role of SAFB in invasion, metastasis, and angiogenesis was investigated using in vitro and in vivo assays. The relationship between SAFB and TAK1 was analyzed in CRC tissues.Results: SAFB was downregulated in CRC tissues, and low expression of SAFB was significantly associated with an aggressive phenotype and poorer survival of CRC patients. The downregulation of SAFB activated NF-κB signaling by targeting the TAK1 promoter. Ectopic expression of SAFB inhibited the development of aggressive features and metastasis of CRC cells both in vitro and in vivo The overexpression of TAK1 could rescue the aggressive features in SAFB-overexpressed cells. Furthermore, the expression of SAFB in CRC tissues was negatively correlated with the expression of TAK1- and NF-κB-related genes.Conclusions: Our results show that SAFB regulated the activity of NF-κB signaling in CRC by targeting TAK1 This novel mechanism provides a comprehensive understanding of both SAFB and the NF-κB signaling pathway in the progression of CRC and indicates that the SAFB-TAK1-NF-κB axis is a potential target for early therapeutic intervention in CRC progression. Clin Cancer Res; 23(22); 7108-18. ©2017 AACR.

Association between single nucleotide polymorphisms in the antioxidant genes CAT, GR and SOD1, erythrocyte enzyme activities, dietary and life style factors and breast cancer risk in a Danish, prospective cohort study

Exposure to estrogens and alcohol consumption - the two only well-established risk factors for breast cancer - are capable of causing oxidative stress, which has been linked to progression of breast cancer. Here, five functional polymorphisms in the antioxidant genes SOD1, CAT and GSR were investigated in 703 breast cancer case-control pairs in the Danish, prospective “Diet, Cancer and Health” cohort together with gene-environment interactions between the polymorphisms, enzyme activities and intake of fruits and vegetables, alcohol and smoking in relation to breast cancer risk. Our results showed that genetically determined variations in the antioxidant enzyme activities of SOD1, CAT and GSR were not associated with risk of breast cancer per se. However, intake of alcohol, fruit and vegetables, and smoking status interacted with some of the polymorphisms in relation to breast cancer risk. Four polymorphisms were strongly associated with enzyme activity, but there was no interaction between any of the studied environmental factors and the polymorphisms in relation to enzyme activity. Additionally, single measurement of enzyme activity at entry to the cohort was not associated with risk of breast cancer. Our results therefore suggest that the antioxidant enzyme activities studied here are not major determinants of breast cancer risk.

Coexpression of growth differentiation factor 11 and reactive oxygen species in metastatic oral cancer and its role in inducing the epithelial to mesenchymal transition

OBJECTIVES

The aim of this study was to investigate growth differentiation factor 11 (GDF11) and reactive oxygen species (ROS) expression in metastatic oral cancer and explored their roles in inducing epithelial to mesenchymal transition (EMT).

STUDY DESIGN

The expression of GDF11, ROS, and EMT-related markers was evaluated in primary tumor tissues from patients with oral squamous cell carcinoma (OSCC). SCC-9 cells, a human tongue carcinoma cell line, were treated with recombinant GDF11. Induction of EMT, expression of EMT-related markers, and the effect of ROS on EMT in SCC-9 cells were analyzed.

RESULTS

Overexpression of GDF11 and ROS was observed in patients with metastatic oral cancer. Downregulated expression of E-cadherin and upregulated expression of vimentin, δ-EF1, SIP-1, MMP-2, and MMP-9 were observed in patients with metastatic oral cancer, relative to the expression of these factors in patients with nonmetastatic oral cancer. With recombinant GDF11 treatment, obvious spindle-shaped cells appeared, and gene expressions of EMT-related markers were altered in SCC-9 cells. Treatment with the powerful antioxidant N-acetylcysteine inhibited GDF11-induced EMT and cell migration.

CONCLUSIONS

GDF11 induces EMT and cell migration with ROS involvement in SCC-9 cells. Overexpression of GDF11 and ROS is associated with metastatic oral cancer. GDF11 and ROS may participate in metastasis of oral cancer through EMT.

The one-carbon metabolism pathway highlights therapeutic targets for gastrointestinal cancer (Review)

After the initial use of anti-folates for treatment of malignancies, folate metabolism has emerged as a rational diagnostic and therapeutic target in gastrointestinal cancer. The one-carbon metabolic pathway, which comprises three critical reactions (i.e., folate and methionine cycles), underlies this effect in conjunction with the trans-sulfuration pathway. Understanding of the one-carbon metabolism pathway has served to unravel the link between the causes and effects of cancer phenotypes leading to several seminal discoveries such as that of diadenosine tri-phosphate hydrolase, microRNAs, 5-FU and, more recently, trifluridine. In the folate cycle, glycine and serine fuel the mitochondrial enzymes SHMT2, MTHFD2 and ALDH1L2, which play critical roles in the cancer survival and proliferation presumably through purine production. In the methionine cycle, S-adenocyl methionine serves hydrocarbons and polyamines that are critical for the epigenetic controls. The trans-sulfuration pathway is a critical component in the synthesis of glutathione, which is involved in the production of reactive oxygen species in cancer stem cells. Therefore, characterization of one-carbon metabolism is indispensable to the development of precision medicine in the context of cancer diagnostics and therapeutics. In the present study, we review the historical issues associated with one-carbon metabolism and highlight the recent advances in cancer research.

The Role of Biomarkers of Oxidative Stress in Breast Cancer Risk and Prognosis: A Systematic Review of the Epidemiologic Literature

BACKGROUND

Oxidative stress may play an important role in both initiation and progression of breast cancer. We conducted the first systematic epidemiologic review to summarize the published literature on oxidative stress biomarkers and breast cancer.

MATERIALS AND METHODS

We implemented systematic search strategies to identify published studies of oxidative stress biomarkers and (1) risk of developing breast cancer and (2) breast cancer prognosis using the PRISMA statement guidelines.

RESULTS

We identified eleven case-control studies of oxidative stress biomarkers and breast cancer. Biomarkers utilized varied and menopausal status was a key modifying factor. Across three nested case-control studies with biomarkers measured before diagnosis, one reported increased risk of postmenopausal breast cancer in association with 8-oxodG (DNA damage biomarker), while two (one of F₂-isoprostanes and one of fluorescent oxidation products) reported inverse associations for premenopausal breast cancer only. We identified eight prognostic studies. Two reported associations for lipid peroxidation and breast cancer prognosis; results for other studies were null.

CONCLUSIONS

DNA damage may increase risk of breast cancer among postmenopausal women, while lipid peroxidation may be inversely associated with premenopausal breast cancer. Lipid peroxidation may be associated with survival after breast cancer diagnosis; however, results require evaluation in large, prospective cohort studies.

Effects of exercise on markers of oxidative stress: an Ancillary analysis of the Alberta Physical Activity and Breast Cancer Prevention Trial

BACKGROUND

Oxidative stress may contribute to cancer aetiology through several mechanisms involving damage to DNA, proteins and lipids leading to genetic mutations and genomic instability. The objective of this study was to determine the effects of aerobic exercise on markers of oxidative damage and antioxidant enzymes in postmenopausal women.

METHODS

The Alberta Physical Activity and Breast Cancer Prevention Trial (ALPHA) was a two-centre, two-armed randomised trial of 320 inactive, healthy, postmenopausal women aged 50-74 years. Participants were randomly assigned to a year-long exercise intervention (225 min/week) or a control group while being asked to maintain a normal diet. Fasting blood samples were obtained and plasma concentrations of two oxidative damage markers (8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-isoprostaglandin F2α (8-Iso-PGF2α)) and two antioxidant enzymes (superoxide dismutase and catalase) were measured at baseline, 6 months and 12 months. Intention-to-treat (ITT) and per-protocol analyses were performed using linear mixed models adjusted for baseline biomarker concentrations. A further exercise adherence analysis, based on mean minutes of exercise per week, was also performed.

RESULTS

In the ITT and per-protocol analyses, the exercise intervention did not have any statistically significant effect on either oxidative damage biomarkers or antioxidant enzyme activity.

CONCLUSIONS

A year-long aerobic exercise intervention did not have a significant impact on oxidative stress in healthy, postmenopausal women.

TRIAL REGISTRATION NUMBER

NCT00522262.

Proteomic changes associated with metabolic syndrome in a fructose-fed rat model

Metabolic syndrome (MetS), characterized by a constellation of disorders such as hyperglycemia, insulin resistance, and hypertension, is becoming a major global public health problem. Fructose consumption has increased dramatically over the past several decades and with it the incidence of MetS. However, its molecular mechanisms remain to be explored. In this study, we used male Sprague-Dawley (SD) rats to study the pathological mechanism of fructose induced MetS. The SD rats were fed a 60% high-fructose diet for 16 weeks to induce MetS. The induction of MetS was confirmed by blood biochemistry examination. Proteomics were used to investigate the differential hepatic protein expression patterns between the normal group and the MetS group. Proteomic results revealed that fructose-induced MetS induced changes in glucose and fatty acid metabolic pathways. In addition, oxidative stress and endoplasmic reticulum stress-related proteins were modulated by high-fructose feeding. In summary, our results identify many new targets for future investigation. Further characterization of these proteins and their involvement in the link between insulin resistance and metabolic dyslipidemia may bring new insights into MetS.

Single-Nucleotide Polymorphisms and Markers of Oxidative Stress in Healthy Women

Purpose

There is accumulating evidence that oxidative stress is an important contributor to carcinogenesis. We hypothesized that genetic variation in genes involved in maintaining antioxidant/oxidant balance would be associated with overall oxidative stress.

Methods

We examined associations between single nucleotide polymorphisms (SNPs) in MnSOD, GSTP1, GSTM1, GPX1, GPX3, and CAT genes and thiobarbituric acid-reactive substances (TBARS), a blood biomarker of oxidative damage, in healthy white women randomly selected from Western New York (n = 1402). We used general linear models to calculate age-adjusted geometric means of TBARS across the variants. We also examined the associations within strata of menopausal status.

Results

For MnSOD, being heterozygous was associated with lower geometric means of TBARS (less oxidative stress), 1.28 mg/dL, compared to homozygous T-allele or homozygous C-allele,1.35 mg/dL, and 1.31 mg/dL correspondingly (p for trend = 0.01). This difference remained among postmenopausal women, 1.40 mg/dL for TT, 1.32 mg/dL for TC, and 1.34mg/dL for CC (p for trend 0.015); it was attenuated among premenopausal women. SNPs in the other genes examined (GSTP1, GSTM1, GPX1, GPX3, and CAT) were not associated with TBARS.

Conclusions

Our findings suggest that genetic variation in MnSOD gene may be associated with oxidative status, particularly among postmenopausal women.

Association between L55M polymorphism in Paraoxonase 1 and cancer risk: a meta-analysis based on 21 studies

L55M polymorphism in Paraoxonase 1 (PON1) has been regarded as a risk factor for many cancer types. Nevertheless, the results remain controversial and inconclusive. We therefore performed a meta-analysis of all eligible case–control studies to evaluate the association between L55M polymorphism and cancer risk. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the associations. Finally, a total of 5,627 cases and 6,390 controls, arising from 21 case–control studies, were enrolled in our study. Significant associations between PON1-L55M polymorphism and overall cancer risk were identified in all genetic models. In the stratified analyses by cancer type, PON1-L55M polymorphism was a risk factor for breast cancer in all genetic models, prostate cancer in the heterozygote model (ML vs LL: OR =1.304, 95% CI =1.049–1.620, P_{heterogeneity}=0.067), and ovarian cancer in the recessive model (MM vs ML/LL: OR =1.526, 95% CI =1.110–2.097, P_{heterogeneity}=0.464). Similarly, an increased risk was also identified for the Caucasian population in the heterozygote comparison and homozygote models, and hospital-based controls in all genetic models. To sum up, our study suggests that the PON1-L55M allele increased the risk of cancer. Future well-designed studies with larger sample sizes are warranted to further verify these findings.

The C609T (Pro187Ser) Null Polymorphism of the NQO1 Gene Contributes Significantly to Breast Cancer Susceptibility in North Indian Populations: a Case Control Study

BACKGROUND

Worldwide, breast cancer is the most common cancer among women and is a leading cause of cancer death. In the present study, we investigated the NQO1 C609T genotypic and allelic distribution in north Indian breast cancer patients.

MATERIALS AND METHODS

The genotypic distribution of the NQ01 C609T polymorphism was assessed in 100 invasive ductal carcinoma (IDC) breast cancer patients and 100 healthy controls using allele specific PCR (AS-PCR).

RESULTS

A lower frequency of the CC genotype was found in breast cancer patients (24%) than in the controls. On the other hand, TT genotype frequency was also found to be higher in female healthy controls (32%) than the female breast cancer patients (20%). The frequencies of all three genotypes CC, CT, TT in patients were 24%, 56% and 20% and in healthy controls 50%, 22% and 32% respectively. We did not find any significant correlation between the NQO1 C609T polymorphism and age group, grading, menopausal status and distant metastasis. A less significant association was found between the NQ01 C609T polymorphism and the stage of breast cancer (X2=5.931, P=0.05).

CONCLUSIONS

The present study shows a strong association between NQO1 C609T polymorphism with the breast cancer risk in the north Indian breast cancer patients so that possible use as a risk factor should be further explored.

Detection of volatile organic compounds (VOCs) from exhaled breath as noninvasive methods for cancer diagnosis

The detection of cancer at an early stage is often significant in the successful treatment of the disease. Tumor cells have been reported to generate unique cancer volatile organic compound (VOC) profiles which can reflect the disease conditions. The detection and analysis of VOC biomarkers from exhaled breath has been recognized as a new frontier in cancer diagnostics and health inspections owing to its potential in developing rapid, noninvasive, and inexpensive cancer screening tools. To detect specific VOCs of low concentrations from exhaled breath, and to enhance the accuracy of early diagnosis, many breath collection and analysis approaches have been developed. This paper will summarize and critically review the exhaled-breath VOC-related sampling, collection, detection, and analytical methods, especially the recent development in VOC sensors. VOC sensors are commonly inexpensive, portable, programmable, easy to use, and can obtain data in real time with high sensitivities. Therefore, many sensor-based VOC detection techniques have huge potential in clinical point-of-care use.

The role of base excision repair in pathogenesis of breast cancer in the Polish population

Breast cancer (BC) is leading type of cancer among group of women, which determines almost 23% of invasive cancers. It has been reported repeatedly that the level of oxidative stress is higher for BC in comparison to cancer-free woman. The goal of the present study was to evaluate the role of base excision repair (BER) pathway in the development of BC. One-hundred seventy-one women with confirmed BC and 222 healthy controls were enrolled in presented study. The level of oxidative DNA damage and the kinetic of their repair were analyzed by the modified alkaline comet assay. The efficiency of BER pathway was evaluated by BER assay. The presence of the 326Cys/Cys genotype and 326Cys allele of OGG1 gene and the 324His/His of MUTYH gene are associated with increased risk of BC development. Moreover, correlation between clinical parameter with selected genes has shown increased risk of BC progression. The survival analysis has shown a significant lower DFS for individuals with the 762Ala/Ala genotype compared to 762Val/Vla carriers and the 762Val/Ala genotype in relation to concomitant chemotherapy and radiotherapy. In subgroup of patients with alone chemotherapy and alone radiotherapy, the 762Val/Val genotype was significantly associated with lower overall survival. Furthermore, we also elevated the level of basal and oxidative DNA damage in a group of patients with BC in relation to healthy controls. We also observed the difference in effectiveness of DNA damage repair. The results of present studies suggested the important role of BER pathway in BC development. © 2015 Wiley Periodicals, Inc.

Status of oxidative stress and antioxidant levels in smokers with breast cancer from western Nepal

BACKGROUND

Research indicates that oxidative stress induced by smoking plays a role in breast cancer. In view of these reports, we aimed to study th relationship between smoking and oxidative stress in breast cancer patients from the western region of Nepal.

MATERIALS AND METHODS

The study included a control group of 42 females (non-smoking healthy women) and a test group sudivided into Group I consisting of 46 female breast cancer patients who were smokers and Group II consisting of 42 non-smoking breast cancer patients. Detailed history of the patients was collected with the help of pre-test proforma. Plasma levels of malondialdehyde (MDA), total antioxidant activity (TAA) which represents total dietary antioxidants, vitamin C and α- tocopherol were estimated by standard methods. Statistical analysis was done using SPSS version 16.

RESULTS

The plasma MDA, TAA, vitamin C and α- tocopherol were 1±1.4nmol/ml, 918±207μmol/L, 1±0.24mg/dL and 0.94±0.31mg/dL in controls, 5±1.2nmol/ml, 458±166 μmol/L, 0.64±0.32mg/dL and 0.5±0.3mg/dL in Group-I and 2.56±1.2nmol/ml, 663±178 μmol/L, 0.78±0.2mg/dL and 0.77±0.2mg/dL in Group- II, respectively. Vitamin C, α- tocopherol and TAA (p=0.001) were significantly reduced whereas MDA (p=0.001) was significantly raised in Group-I when compared to controls and Group-II.

CONCLUSIONS

We observed a significant rise in oxidative stress and low levels of antioxidants in breast cancer patients with smoking habit. It is well known that free radicals facilitate the progression of breast cancer, possibly increasing the risk of progression to the next stage.

Redox Regulation in Cancer Stem Cells

Reactive oxygen species (ROS) and ROS-dependent (redox regulation) signaling pathways and transcriptional activities are thought to be critical in stem cell self-renewal and differentiation during growth and organogenesis. Aberrant ROS burst and dysregulation of those ROS-dependent cellular processes are strongly associated with human diseases including many cancers. ROS levels are elevated in cancer cells partially due to their higher metabolism rate. In the past 15 years, the concept of cancer stem cells (CSCs) has been gaining ground as the subpopulation of cancer cells with stem cell-like properties and characteristics have been identified in various cancers. CSCs possess low levels of ROS and are responsible for cancer recurrence after chemotherapy or radiotherapy. Unfortunately, how CSCs control ROS production and scavenging and how ROS-dependent signaling pathways contribute to CSCs function remain poorly understood. This review focuses on the role of redox balance, especially in ROS-dependent cellular processes in cancer stem cells (CSCs). We updated recent advances in our understanding of ROS generation and elimination in CSCs and their effects on CSC self-renewal and differentiation through modulating signaling pathways and transcriptional activities. The review concludes that targeting CSCs by manipulating ROS metabolism/dependent pathways may be an effective approach for improving cancer treatment.

MnSOD and CAT polymorphisms modulate the effect of the Mediterranean diet on breast cancer risk among Greek-Cypriot women

PURPOSE

Oxidative stress arises due to a cellular imbalance in oxidants and antioxidants and/or due to an altered activity of antioxidant enzymes, caused by SNPs. Oxidative stress increases susceptibility to breast cancer (BC) risk, and we previously showed that the Mediterranean diet (MD), which is rich in antioxidants, reduces BC risk in Greek-Cypriot women. Here, we investigated the effect of MnSOD (p.Val16Ala, rs4880) and CAT (-262C>T, rs1001179) SNPs on the association between the MD and BC risk in the case-control study of BC MASTOS in Cyprus.

METHODS

Dietary intake data were obtained using a 32-item food frequency questionnaire, from which a dietary pattern was previously derived, using principal component analysis. This pattern included high loadings of vegetables, fruit, legumes and fish, a combination that closely resembles the MD and was used as our dietary variable.

RESULTS

High vegetable intake lowered BC risk in women with at least one MnSOD Val allele (ORHigh vs. Low for Val/Val = 0.56, 95 % CI 0.35-0.88, for Val/Ala = 0.57, 95 % CI 0.39-0.82), or one CAT -262C allele (ORHigh vs. Low for -262CC = 0.66, 95 % CI 0.47-0.92, for -262CT = 0.53, 95 % CI 0.35-0.81). High fish intake conferred a decreased BC risk of CAT -262CC women (ORQ4 vs. Q1 0.66, 95 % CI 0.47-0.92) compared with the CAT -262TT women and low fish intake (ORQ2 vs. Q1 2.79, 95 % CI 1.08-7.17). Additionally, high fish intake reduced BC risk in MnSOD Val/Val women (ORQ4 vs. Q1 0.63, 95 % CI 0.40-0.98). p interaction values were, however, not statistically significant.

CONCLUSION

Our results demonstrate that the antioxidative effects of the MD against BC risk may be enhanced by the wild-type alleles of the MnSOD or CAT SNPs among Greek-Cypriot women.