Diet and biomarkers of oxidative damage in women previously treated for breast cancer

Dietary Antioxidant Capacity Promotes a Protective Effect against Exacerbated Oxidative Stress in Women Undergoing Adjuvant Treatment for Breast Cancer in a Prospective Study

Breast cancer (Bca) is the most common type of cancer among women worldwide, and oxidative stress caused by adjuvant treatment may be decreased by antioxidant intake. The aim of this study is to investigate the associations between Dietary antioxidant Capacity (DaC) and oxidation and antioxidant biomarkers in women undergoing adjuvant treatment (AT) for Bca. This prospective study had a sample of 70 women (52.2 ± 10.7 y). DaC (mmol/g) was calculated using nutritional data obtained from a Food Frequency Questionnaire, and blood was collected to measure the oxidation and antioxidant biomarkers at baseline (T0), and after AT (T1). Carbonylated protein levels were inversely associated with DaC at T1 (p = 0.004); women showed an increased risk of having increment on lipid hydroperoxides and thiobarbituric acid reactive substances (TBARS), and decrement on ferric reducing antioxidant power (FRAP) and reduced glutathione after AT, in response to lowered DaC (p < 0.05). Carbonylated proteins, TBARS and FRAP levels remained stable between the periods for women at the 3rd DaC tertile at T1, differentiating them from those at the 1st tertile, who showed negative changes in these biomarkers (p < 0.04). DaC may be beneficial for women undergoing AT for Bca, since it promoted a reduction in oxidative stress.

Diet Quality Is Associated with Serum Antioxidant Capacity in Women with Breast Cancer: A Cross Sectional Study

Oxidative stress produced by adjuvant treatments is associated with cell injury; however, a healthy diet can help mitigate it. The aim of this study is to investigate the association between diet quality and oxidative stress parameters in women subjected to adjuvant treatment for breast cancer. The sample comprised 70 women. Oxidative stress biomarkers and diet quality parameters based on the Brazilian Healthy Eating Index-Revised (BHEI-R)-were evaluated at baseline (p0) and after adjuvant treatment (p1). Ferric reducing antioxidant potential (FRAP) was associated with diet quality at p0. BHEI-R scores were not different between p0 and p1; however, scores from total vegetables, total fruits, milk and dairy products, and meat, eggs and legumes were lower during treatment. On the other hand, lower sodium and saturated fat intake observed at p1 counterbalanced the BHEI-R score. Oxidative stress parameters have increased at p1, but they were not associated with diet quality; thus, changes in component intake were not enough to promote changes in oxidative stress during treatment. It appears that diet can enhance patients' antioxidant defense before treatment, which could lead to better outcomes in the long term. Further investigations may help to clarify the association between diet and oxidative stress in women with 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.

Citrus aurantium Naringenin Prevents Osteosarcoma Progression and Recurrence in the Patients Who Underwent Osteosarcoma Surgery by Improving Antioxidant Capability

Citrus aurantium is rich in flavonoids, which may prevent osteosarcoma progression, but its related molecular mechanism remains unclear. Flavonoids were extracted from C. aurantium and purified by reparative HPLC. Each fraction was identified by using electrospray ionisation mass spectrometry (ESI-MS). Three main components (naringin, naringenin, and hesperetin) were isolated from C. aurantium. Naringenin inhibited the growth of MG-63 cells, whereas naringin and hesperetin had no inhibitory function on cell growth. ROS production was increased in naringin- and hesperetin-treated groups after one day of culture while the level was always lowest in the naringenin-treated group after three days of culture. 95 osteosarcoma patients who underwent surgery were assigned into two groups: naringenin group (NG, received 20 mg naringenin daily, n = 47) and control group (CG, received 20 mg placebo daily, n = 48). After an average of two-year follow-up, osteosarcoma volumes were smaller in the NG group than in the CG group (P > 0.01). The rate of osteosarcoma recurrence was also lower in the NG group than in CG group. ROS levels were lower in the NG group than in the CG group. Thus, naringenin from Citrus aurantium inhibits osteosarcoma progression and local recurrence in the patients who underwent osteosarcoma surgery by improving antioxidant capability.

The women in steady exercise research (WISER) survivor trial: The innovative transdisciplinary design of a randomized controlled trial of exercise and weight-loss interventions among breast cancer survivors with lymphedema

INTRODUCTION

Breast cancer survivors face dual challenges: long term sequelae of treatment, and risk of recurrent disease. Obesity and a sedentary lifestyle complicate both challenges. The WISER Survivor trial assessed the effects of exercise and/or weight-loss on lymphedema, biomarkers of breast cancer recurrence, and quality of life. We report on the innovative transdisciplinary design of this trial and report attrition rates.

METHODS

This one year trial randomized breast cancer survivors who had a BMI of ≥25kg/m2, were sedentary and had breast-cancer-related-lymphedema to 1) exercise (weight training and aerobic exercise) 2) weight-loss 3) exercise and weight-loss 4) or control group. Innovative aspects included: adaptation of a community-based weight training program to a largely home-based program; use of a commercial meal replacement system as part of the lifestyle modification weight-loss program; inclusion of measures of cost-effectiveness to enable economic evaluations; and alignment with a parallel mouse model for breast cancer recurrence to enable transdisciplinary research. In this model, mice bearing dormant residual tumor cells, which spontaneously relapse, were placed on a high-fat diet. Overweight animals were randomly assigned to exercise, calorie restriction, both, or control group and followed for cancer recurrence. The animal model will guide mechanistic biomarkers to be tested in the human trial.

RESULTS & DISCUSSION

351 participants were randomized; 13 experienced breast cancer recurrence during the trial. Of the 338 participants without recurrence, 83% completed the trial. The WISER Survivor trial will show the effects of exercise and weight-loss on lymphedema outcomes, biomarkers of recurrence and quality of life. NCT ClinicalTrials.gov registration #: NCT01515124.

Effect of Cruciferous Vegetable Intake on Oxidative Stress Biomarkers: Differences by Breast Cancer Status

This post hoc analysis examined cruciferous vegetable intake on urinary oxidative metabolites in postmenopausal women. Intervention participants (n = 69) received cruciferous vegetables (≥14 cups/week) during a 3-week period. First morning urine measured 8-isoprostane and 8-hydroxy-2'-deoxyguanosine. Dietary intake was estimated using 24-h recalls. When stratified by history of breast cancer, those with breast cancer had significantly lower post-intervention urinary 8-hydroxy-2'-deoxyguanosine values in the intervention arm versus. the control arm (1.1 ng/mL vs. 3.2 ng/mL, p = .01) after adjustment for baseline 8-hydroxy-2'-deoxyguanosine. This was not observed in those without breast cancer. Further work is needed to understand the role of breast cancer in these relationships.

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.

Nutrition education intervention for women with breast cancer: effect on nutritional factors and oxidative stress

OBJECTIVES

To assess the effect of a nutrition education intervention on nutritional factors and oxidative stress during treatment of breast cancer.

DESIGN

Nonrandomized clinical trial conducted in 2010-2011, including an evaluation at baseline and after 12 months.

PARTICIPANTS

Women from Brazil who had breast cancer, divided into an intervention group (IG) (n = 18) and comparison group (n = 75).

INTERVENTION

To increase intake of fruits and vegetables and reduce red and processed meats, via telephone and printed materials.

MAIN OUTCOME MEASURES

Food intake, anthropometry, and levels of lipid hydroperoxide, carbonyl proteins, reduced glutathione, and ferric reducing antioxidant power.

ANALYSES

Chi-square, Mann-Whitney or t tests for baseline data; Wilcoxon or paired t tests for intra-group outcomes, linear regression models, and Bonferroni multiplicity adjustment.

RESULTS

The researchers observed an increase in fruit and vegetable intake, reduction in red and processed meat intake, no change in body weight, and an increase in glutathione in the IG over the comparison group. However, after Bonferroni adjustment, only the consumption of fruits and vegetables and fruit was significantly higher in IG.

CONCLUSIONS AND IMPLICATIONS

This study presents improved dietary changes after a theory-driven nutrition education intervention. Although the sample size is small, it has proven to be clinically relevant.

Urinary biomarkers of oxidative stress and breast cancer survival

PURPOSE

Systemic oxidative stress has been implicated in the pathogenesis and progression of many chronic diseases, including breast cancer. No studies have investigated F2-isoprostanes (F2-IsoPs), valid biomarkers of systemic oxidative stress, in association with breast cancer prognosis. We conducted a nested case-control study in a prospective breast cancer survivor cohort to investigate systemic oxidative stress and survival.

METHODS

Urinary levels of F2-IsoPs and its major urinary metabolite (2,3-dinor-5,6-dihydro-15-F2t-IsoP, F2-IsoP-M) were measured post-cancer treatment using gas chromatography/negative ion chemical ionization mass spectrometry for 57 deceased breast cancer patients (cases) and 103 surviving patients (controls) matched 1:2 on age at diagnosis, stage, and diagnosis year. Odds ratios (ORs) and 95 % confidence intervals (CIs) were derived from conditional logistic regression models.

RESULTS

In unadjusted models, elevated F2-IsoP levels categorized based on the median value [≥1.73; <1.73 (reference)] were nonsignificantly inversely associated with mortality (OR 0.51, 95 % CI 0.24-1.10). After adjustment for potential confounders, elevated F2-IsoP levels were significantly associated with mortality (OR 0.36, 95 % CI 0.14-0.96). The inverse association was marginally significant when F2-IsoP was categorized based on tertiles (p trend = 0.08). In contrast, elevated F2-IsoP-M levels, categorized based on the median level [≥0.91; < 0.91(reference)], were associated with a statistically nonsignificant increased risk of mortality in both unadjusted and adjusted models (adjusted OR 1.39, 95 % CI 0.62-3.09).

CONCLUSION

Results suggest a role for oxidative stress biomarkers in breast cancer survival; however, as this is the first study to date, additional larger studies are needed.

Senescence evasion by MCF-7 human breast tumor-initiating cells

Introduction

A subpopulation of cancer cells, tumor-initiating cells, is believed to be the driving force behind tumorigenesis and resistance to radiation and chemotherapy. The persistence of tumor-initiating cells may depend on altered regulation of DNA damage and checkpoint proteins, as well as a reduced propensity to undergo apoptosis or senescence.

Methods

To test this hypothesis, we isolated CD24^-/low/CD44⁺ tumor-initiating cells (as mammospheres) from MCF-7 breast cancer cells grown in adherent monolayer culture, and carried out a comprehensive comparison of cell death and DNA damage response pathways prior to and after exposure to ionizing radiation in mammospheres and monolayer MCF-7 cells. Single and double-strand break repair was measured by single-cell gel electrophoresis. The latter was also examined by phosphorylation of histone H2AX and formation of 53BP1 and Rad51 foci. Apoptosis was quantified by flow-cytometric analysis of annexin V-binding and senescence was analyzed on the basis of cellular β-galactosidase activity. We employed the telomeric repeat amplification protocol to quantify telomerase activity. Expression of key DNA repair and cell cycle regulatory proteins was detected and quantified by western blot analysis.

Results

Our data demonstrate that in comparison to the bulk population of MCF-7 cells (predominantly CD24⁺/CD44⁺), the MCF-7 mammosphere cells benefit from a multifaceted approach to cellular protection relative to that seen in monolayer cells, including a reduced level of reactive oxygen species, a more active DNA single-strand break repair (SSBR) pathway, possibly due to a higher level of expression of the key SSBR protein, human AP endonuclease 1 (Ape1), and a significantly reduced propensity to undergo senescence as a result of increased telomerase activity and a low level of p21 protein expression. No significant difference was seen in the rates of double-strand break repair (DSBR) between the two cell types, but DSBR in mammospheres appears to by-pass the need for H2AX phosphorylation.

Conclusions

Enhanced survival of MCF-7 tumor-initiating cells in response to ionizing radiation is primarily dependent on an inherent down-regulation of the senescence pathway. Since MCF-7 cells are representative of cancer cells that do not readily undergo apoptosis, consideration of senescence pathways may play a role in targeting stem cells from such tumors.

Dietary reference values of individual micronutrients and nutriomes for genome damage prevention: current status and a road map to the future

Damage to the genome is recognized as a fundamental cause of developmental and degenerative diseases. Several micronutrients play an important role in protecting against DNA damage events generated through endogenous and exogenous factors by acting as cofactors or substrates for enzymes that detoxify genotoxins as well as enzymes involved in DNA repair, methylation, and synthesis. In addition, it is evident that either micronutrient deficiency or micronutrient excess can modify genome stability and that these effects may also depend on nutrient-nutrient and nutrient-gene interaction, which is affected by genotype. These observations have led to the emerging science of genome health nutrigenomics, which is based on the principle that DNA damage is a fundamental cause of disease that can be diagnosed and nutritionally prevented on an individual, genetic subgroup, or population basis. In this article, the following topics are discussed: 1) biomarkers used to study genome damage in humans and their validation, 2) evidence for the association of genome damage with developmental and degenerative disease, 3) current knowledge of micronutrients required for the maintenance of genome stability in humans, 4) the effect of nutrient-nutrient and nutrient-genotype interaction on DNA damage, and 5) strategies to determine dietary reference values of single micronutrients and micronutrient combinations (nutriomes) on the basis of DNA damage prevention. This article also identifies important knowledge gaps and future research directions required to shed light on these issues. The ultimate goal is to match the nutriome to the genome to optimize genome maintenance and to prevent pathologic amounts of DNA damage.

Impact of fish intake on oxidative stress when included into a moderate energy-restricted program to treat obesity

BACKGROUND

The role of some nutritional factors and hypocaloric diets on oxidative balance is a matter of debate, especially related to the prevention and treatment of obesity and co-morbidities.

AIM OF THE STUDY

The aim was to investigate the antioxidant capacity of different energy restricted diets in the treatment of obesity, paying emphasis to the effect of incorporating omega-3 fatty acids with or without other seafood components.

METHODS

The study was a randomized 8-weeks parallel intervention trial prescribed to lose weight, which was implemented in 276 subjects aged 31.4 +/- 5.4 y.o. following four different balanced hypocaloric diets (TEE-30%): fish-restricted (control), cod and salmon based diets and DHA+EPA supplemented administration. At baseline (day 0) and at the end of the trial (day 56), anthropometry, dietary intake, erythrocyte membrane fatty acid content, circulating malondialdehyde (MDA) and plasma antioxidant status (AOP) were determined.

RESULTS

Overall, percent weight loss was -5.8 +/- 3.2% (P < 0.001) and the AOP statistically increased after the energy restriction period (P = 0.015), basically due to the seafood-based diets. In contrast, MDA statistically only decreased (P = 0.026) after the cod-based diet intake with no changes after the other nutritional treatments. In fact, the cod-based intervention statistically decreased oxidative stress when expressed as the MDA/AOP ratio (P = 0.006).

CONCLUSIONS

A moderate calorie-restricted cod-based diet was found as a useful strategy to lose weight, which was accompanied by a specific improvement on oxidative stress markers. The low saturated fat content and the seafood protein source of this diet may be important factors involved in these findings.

Vasoactive biomarkers and oxidative stress in healthy recently postmenopausal women treated with hormone replacement therapy

BACKGROUND

Despite biologically plausible mechanisms for cardiac protection from estrogen therapy, recent clinical trials have suggested possible cardiovascular risk rather than benefit. However, it has been speculated that cardioprotective benefits from hormone replacement therapy (HRT) may be more evident in the early postmenopausal period. We have previously reported early beneficial effects on biochemical markers of endothelial function in healthy women after short-term estradiol replacement therapy. In this study we aimed to evaluate the effect of long-term HRT on different vasoactive factors and oxidative stress in healthy recently postmenopausal women.

METHODS

Fifteen women (age 50 +/- 1 years, time since menopause 1.6 +/- 0.1 years) were randomized to a sequential oral and transdermal estradiol regimen (2 mg oral micronized 17beta-estradiol/day or 1.5 mg 17beta-estradiol gel/day). Oral dydrogesterone (10 mg/day, 12 days/month) was then cyclically combined with either of the estrogen therapies for 1 year. Blood samples were collected at baseline and after 1, 2, 6 and 12 months of therapy to evaluate levels of follicle stimulating hormone (FSH), estradiol, 6-keto PGF1alpha (prostacyclin metabolite), nitrite/nitrate, epinephrine, norepinephrine, 8-isoprostane (8-epi PGF2alpha) and lipid profile values.

RESULTS

FSH levels decreased (p < 0.001) while estradiol levels increased (p < 0.001) during HRT. Levels of epinephrine (p < 0.001), norepinephrine (p < 0.01), mean blood pressure (p < 0.01) and low density lipoprotein (LDL) cholesterol (p < 0.01) decreased, and nitrite/nitrate levels increased (p < 0.01) during HRT, which did not significantly affect 8-epi PGF2alpha levels.

CONCLUSIONS

One-year HRT significantly reduced the levels of catecholamines, mean blood pressure and LDL cholesterol while it increased levels of nitrite/nitrate, indicating cardiovascular benefit in healthy recent postmenopausal women. Levels of 8-epi PGF2alpha did not change, suggesting no evident relationship between HRT and oxidative stress.

Effects of High Fruit-Vegetable and/or Low-Fat Intervention on Breast Nipple Aspirate Fluid Micronutrient Levels

BACKGROUND

A change in diet is known to affect micronutrient levels in blood but to what extent diet can affect micronutrient levels in the breast is not yet well established.

METHODS

Healthy, premenopausal women with a family history of breast cancer were randomized across four diet arms for 1 year in a 2 x 2 factorial design study: control, low-fat, high fruit-vegetable, and combination low-fat/high fruit-vegetable diets. Subjects were asked to collect breast nipple aspirate fluid (NAF) at 0, 6, and 12 months, and levels of micronutrients were measured in the fluid.

RESULTS

A total of 122 women were enrolled, 97 were retained for 12 months, and sufficient NAF for analysis was available from 59 women at baseline, 49 at 6 months, and 50 at 12 months. Repeated measures mixed-model ANOVA was used to model the data using cholesterol levels and lactation duration as covariates, where appropriate. The high fruit-vegetable intervention, regardless of fat intake, significantly increased total carotenoid levels in NAF. In the low-fat arm, levels of total carotenoids decreased over time relative to control. Levels of total tocopherols and retinol did not change significantly. Levels of 15-F(2t)-isoprostane, a marker of lipid peroxidation, also did not change significantly over time, although there was a decrease observed in the combination arm.

CONCLUSIONS

These results indicate that total carotenoid levels in NAF can be significantly increased in the breast NAF with a high fruit-vegetable diet. A low-fat diet that was achieved with little increase in fruit and vegetable intake, however, decreased NAF carotenoid levels.

Urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) and genetic polymorphisms in breast cancer patients

Reactive oxygen species (ROS) causes damage to DNA, but the role of ROS in breast carcinoma is still not clear. The objective of this study was to measure the urinary 8-OHdG levels of breast cancer patients at each stage of carcinogenesis and assess its association with the development of breast cancer. Sixty patients with malignant breast tumors were matched with 60 control subjects of the same ages in this case control study. Urinary 8-OHdG levels were significantly higher among breast cancer patients than among the control subjects, after making adjustments for confounders such as smoking, coffee consumption and use of oral contraceptives. The breast cancer patients were divided into three groups based on the stages of their cancer; urinary 8-OHdG levels decreased with each stage of breast carcinoma. Using multiple regression and logistic models adjusted for other covariates, urinary 8-OHdG levels significantly correlated with the development of breast cancer. However, it was found that breast cancer was not significantly influenced by CYP1A1, CYP1M1 or NAT2 polymorphisms. In conclusion, it was found that oxygen radical generation occurred within carcinoma cells, but the role of polymorphism of specific genes in the development of breast cancer should be evaluated.

Relationship between urinary 15-F2t-isoprostane and 8-oxodeoxyguanosine levels and breast cancer risk

To evaluate the role of oxidative stress in breast cancer, we measured urinary levels of 15-F(2t)-isoprostane (15-F(2t)-IsoP) and 8-oxodeoxyguanosine (8-oxodG) in 400 cases and 401 controls, participants of the Long Island Breast Cancer Study Project. We also analyzed the effect of different factors that are associated with oxidative stress and might influence 15-F(2t)-IsoP and 8-oxodG levels. We observed a statistically significant trend in breast cancer risk with increasing quartiles of 15-F(2t)-IsoP levels [odds ratio (OR), 1.25; 95% confidence interval (95% CI), 0.81-1.94; OR, 1.53; 95% CI, 0.99-2.35; OR, 1.88; 95% CI, 1.23-2.88, for the 2nd, 3rd, and 4th quartile relative to the lowest quartile, respectively; P(trend) = 0.002]. Although it is possible that increased levels may reflect the stress associated with recent treatment, the positive association was also observed when the analyses were restricted to case women for whom chemotherapy and radiation therapy had not yet been initiated at the time of the urine collection. The association with the highest quartile compared with lowest quartile of 15-F(2t)-IsoP was similar across strata of age, physical activity, fruit and vegetable intake, alcohol intake, cigarette smoking, body mass index, and menopausal status. We did not observe any association of breast cancer risk with 8-oxodG levels, but when cases with radiation treatment were removed from the analysis, a significant inverse trend (P = 0.04) was observed. Among controls, levels of 15-F(2t)-IsoP were higher among current cigarette smokers but did not differ by the amount of physical activity, fruit and vegetable intake, alcohol intake, body mass index, and menopausal status. Among controls, levels of 8-oxodG were higher among postmenopausal women and current and former cigarette smokers but did not differ by the other factors. In summary, our results suggest that urinary markers of lipid peroxidation and oxidative DNA damage may be associated with breast cancer risk.