Oxidative stress-related genotypes, fruit and vegetable consumption and breast cancer risk

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.

Psychosocial stress and cancer risk: a narrative review

BACKGROUND

It is unclear which psychological factors (stressors, emotional correlates, and psychophysiological markers) induce cancer risk. This currently limits the potential for prevention strategies.

PURPOSE

The aim of this review is to bring forth evidence of stress as a determinant of cancer risk from a public health perspective, written for a broad public of practitioners and scientists.

METHODS

Based on a semisystematic literature search, the impact of different aspects/types of stress and the potential physiological and behavioral pathways are summarized, while highlighting further research, public health and clinical implications.

RESULTS

Between 2007 and 2020, 65 case-control or cohort studies have been identified. Apart from overall cancer ( N = 24), 12 cancer types have been associated with psychological stress with most for breast ( N = 21), colorectal ( N = 11) and lung/prostate/pancreas cancer ( N = 8 each). Although the evidence regarding the mechanisms is still scarce, cancer development in relation to stress might be due to interacting and combined effects of different stress(or) types, but such interaction has not really been tested yet. The path from stress towards cancer incidence consists of a biological pathway with endocrinology and immunology as well as stress-induced behavioral pathways, including smoking, alcoholism, sleep disruption, an unhealthy diet, and low physical activity together with the related phenomenon of obesity.

CONCLUSION

Not only the stress but also the stress-induced lifestyle should be targeted for cancer prevention and treatment. Future research should include a more diverse spectrum of cancer types (not only hormonal related like breast cancer) and of stress measures while also considering behavioral covariates.

Catalase C262T genetic variation and cancer susceptibility: A comprehensive meta-analysis with meta-regression and trial sequential analysis

Background

Several genetic association studies have analyzed the link between the catalase ( CAT) C262T variant and different cancers, but the findings remain controversial. Our research centered on establishing a comprehensive correlation between the C262T variant and different cancers.

Methods

This study was conducted using RevMan 5.4 software following the PRISMA 2020 guidelines. For this meta-analysis, 53 case-control studies (18,258 cases and 47,476 controls) were chosen.

Results

The analysis revealed that three genetic models were statistically linked ( P < 0.05) to overall cancer susceptibility in codominant model 2 (COD2): odds ratio (OR) = 1.16, COD3: OR = 1.21, recessive model (RM): OR = 1.20). After stratification by ethnicity, a significant link ( P < 0.05) was found in Caucasians (COD2: OR = 1.18, COD3: OR = 1.17, over-dominant model (ODM): OR = 1.19) and Asians (COD3: OR = 1.49). Subgroup analyses revealed a significant correlation ( P < 0.05) with blood-and-bone-marrow-related cancer, skin cancer, gastrointestinal-tract-related cancer, prostate cancer, and gynecologic cancer. Three genetic models in population-based controls (COD2: OR = 1.19, COD3: OR = 1.17, RM: OR = 1.19) and two genetic models in hospital-based controls (COD3: OR = 1.40, RM: OR = 1.24) were found to be significantly correlated ( P < 0.05) with cancer. Also, three genetic models for polymerase chain reaction-restriction fragment length polymorphism (COD3: OR = 1.46; RM: OR = 1.34, ODM: OR = 0.80) and three models for MALDI-TOF + MassARRAY (COD2: OR = 1.32, RM: OR = 1.26, allele model: OR = 1.14) genotyping methods showed significant association ( P < 0.05) with cancer. The meta-regression showed that the quality scores might be a source of significant heterogeneity under the COD2 model (coefficient = 0.176, P = 0.029). Trial sequential analysis also validated the adequacy of the sample size on overall findings.

Conclusion

Our results indicate that CAT C262T variant is associated with overall cancer susceptibility, especially in Caucasians and Asians. This variant may also be associated with blood-and-bone-marrow-related, GIT-related, prostate, skin, and gynecological cancers.

Impacts of nutritive and bioactive compounds on cancer development and therapy

For persons who survive with progressive cancer, nutritional therapy and exercise may be significant factors to improve the health condition and life quality of cancer patients. Nutritional therapy and medications are essential to managing progressive cancer. Cancer survivors, as well as cancer patients, are mostly extremely encouraged to search for knowledge about the selection of diet, exercise, and dietary supplements to recover as well as maintain their treatment consequences, living quality, and survival of patients. A healthy diet plays an important role in cancer treatment. Different articles are studied to collect information and knowledge about the use of nutrients in cancer treatment as well as cancer prevention. The report deliberates nutrition and exercise strategies during the range of cancer care, emphasizing significant concerns during treatment of cancer and for patients of advanced cancer, but concentrating mostly on the requirements of the population of persons who are healthy or who have constant disease following their repossession from management. It also deliberates choice nutrition and exercise problems such as dietary supplements, food care, food selections, and weight; problems interrelated to designated cancer sites, and common questions about diet, and cancer survival. Decrease the side effects of medicines both during and after treatment.

The causal effect and impact of reproductive factors on breast cancer using super learner and targeted maximum likelihood estimation: a case-control study in Fars Province, Iran

OBJECTIVES

The relationship between reproductive factors and breast cancer (BC) risk has been investigated in previous studies. Considering the discrepancies in the results, the aim of this study was to estimate the causal effect of reproductive factors on BC risk in a case-control study using the double robust approach of targeted maximum likelihood estimation.

METHODS

This is a causal reanalysis of a case-control study done between 2005 and 2008 in Shiraz, Iran, in which 787 confirmed BC cases and 928 controls were enrolled. Targeted maximum likelihood estimation along with super Learner were used to analyze the data, and risk ratio (RR), risk difference (RD), andpopulation attributable fraction (PAF) were reported.

RESULTS

Our findings did not support parity and age at the first pregnancy as risk factors for BC. The risk of BC was higher among postmenopausal women (RR = 3.3, 95% confidence interval (CI) = (2.3, 4.6)), women with the age at first marriage ≥20 years (RR = 1.6, 95% CI = (1.3, 2.1)), and the history of oral contraceptive (OC) use (RR = 1.6, 95% CI = (1.3, 2.1)) or breastfeeding duration ≤60 months (RR = 1.8, 95% CI = (1.3, 2.5)). The PAF for menopause status, breastfeeding duration, and OC use were 40.3% (95% CI = 39.5, 40.6), 27.3% (95% CI = 23.1, 30.8) and 24.4% (95% CI = 10.5, 35.5), respectively.

CONCLUSIONS

Postmenopausal women, and women with a higher age at first marriage, shorter duration of breastfeeding, and history of OC use are at the higher risk of BC.

Nutrigenetics of antioxidant enzymes and micronutrient needs in the context of viral infections

Sustaining adequate nutritional needs of a population is a challenging task in normal times and a priority in times of crisis. There is no 'one-size-fits-all' solution that addresses nutrition. In relevance to the COVID-19 (coronavirus disease 2019) pandemic crisis, viral infections in general and RNA viruses in particular are known to induce and promote oxidative stress, consequently increasing the body's demand for micronutrients, especially those related to antioxidant enzymic systems, thus draining the body of micronutrients, and so hindering the human body's ability to cope optimally with oxidative stress. Common polymorphisms in major antioxidant enzymes, with world population minor allele frequencies ranging from 0·5 to 50 %, are related to altered enzymic function, with substantial potential effects on the body's ability to cope with viral infection-induced oxidative stress. In this review we highlight common SNP of the major antioxidant enzymes relevant to nutritional components in the context of viral infections, namely: superoxide dismutases, glutathione peroxidases and catalase. We delineate functional polymorphisms in several human antioxidant enzymes that require, especially during a viral crisis, adequate and potentially additional nutritional support to cope with the pathological consequences of disease. Thus, in face of the COVID-19 pandemic, nutrition should be tightly monitored and possibly supplemented, with special attention to those carrying common polymorphisms in antioxidant enzymes.

Nutrigenomics and Breast Cancer: State-of-Art, Future Perspectives and Insights for Prevention

Proper nutrition plays a major role in preventing diseases and, therefore, nutritional interventions constitute crucial strategies in the field of Public Health. Nutrigenomics and nutriproteomics are arising from the integration of nutritional, genomics and proteomics specialties in the era of postgenomics medicine. In particular, nutrigenomics and nutriproteomics focus on the interaction between nutrients and the human genome and proteome, respectively, providing insights into the role of diet in carcinogenesis. Further omics disciplines, like metabonomics, interactomics and microbiomics, are expected to provide a better understanding of nutrition and its underlying factors. These fields represent an unprecedented opportunity for the development of personalized diets in women at risk of developing breast cancer.

The Relationship Between eNOS Polymorphisms With Age, Smoking, Body Mass Index, and Clinicopathologic Parameters in Patients With Breast Cancer in Comparison With a Control Group

INTRODUCTION

Nitric oxide (NO) is a free radical involved in carcinogenesis and is synthesized by endothelial nitric oxide synthase (eNOS). Genetic changes in the eNOS enzyme affect its activity, and the nitric oxide produced by inhibiting apoptosis can lead to cancer cell proliferation and metastasis. In this study, in addition to investigating the relationship between genetic changes in eNOS gene and the risk of breast cancer, the relationship between genotypes of polymorphisms, age, smoking, body mass index, and clinopathologic parameters was also investigated.

MATERIAL AND METHODS

Three functional (Intron 4a/b, T786C, and G894T) and 1 tagging (G10T) polymorphisms of the eNOS gene were examined in 203 patients with breast cancer and 203 control subjects, and their genotypes were identified by restriction fragment length polymorphism polymerase chain reaction.

RESULTS

The T allele in G10T polymorphism increased the risk of breast cancer by 1.503-fold, whereas allele a in Intron 4, T allele in G894T, and C allele in T786C decreased its risk by 0.678-, 0.440-, and 0.525-fold, respectively. GG, GT (G10T), bb and ab (Intron4), GG and TT (G894T), and TT and CC (T786C) genotypes were significantly correlated with body mass index. There was a significant relationship between age and bb genotype, cigarette smoking and genotype ab (Intron 4), and estrogen receptor and GG (G10T) genotype. Tumor invasion factor was also significantly associated with TT (G10T), bb (Intron 4), and TT (T786C) genotypes.

CONCLUSION

Genetic changes in eNOS appear to have a dual role in breast cancer rate owing to changes in NO production and can be introduced as one of the genetic markers involved in breast cancer by evaluating the genotype of different populations.

Effects of eNOS gene polymorphisms on individual susceptibility to cancer: A meta-analysis

BACKGROUND

Whether endothelial nitric oxide synthase (eNOS) polymorphisms are implicated in cancer development remains controversial. Therefore, we performed this study to obtain a more conclusive result on associations between eNOS polymorphisms and cancer.

METHODS

Literature retrieve was conducted in PubMed, Medline and Embase. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Forty-one studies were enrolled for analyses. Pooled overall analyses showed that rs1799983 (dominant model: p = 0.01; recessive model: p = 0.007; allele model: p = 0.005), rs2070744 (recessive model: p = 0.004) and rs869109213 (recessive model: p < 0.0001; allele model: p = 0.02) polymorphisms were all significantly associated with individual susceptibility to cancer. Further subgroup analyses revealed that rs2070744 and rs869109213 polymorphisms were only significantly associated with individual susceptibility to cancer in Caucasians, whereas the rs1799983 polymorphism was significantly associated with individual susceptibility to cancer in both Caucasians and Asians.

CONCLUSIONS

Our findings indicated that rs1799983, rs2070744 and rs869109213 polymorphisms may serve as genetic biomarkers of cancer in certain ethnicities.

Two common functional catalase gene polymorphisms (rs1001179 and rs794316) and cancer susceptibility: evidence from 14,942 cancer cases and 43,285 controls

Recent studies have focused on the associations of catalase polymorphisms with various types of cancer, including cervical and prostate cancers. However, the results were inconsistent. To obtain a more reliable conclusion, we evaluated the relationship between the two common catalase gene polymorphisms (rs1001179 and rs794316) and cancer risk by a meta-analysis. Our meta-analysis included 37 published studies involving 14,942 cancer patients and 43,285 cancer-free controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the cancer risk. The results demonstrated that the rs1001179 polymorphism was associated with an increased cancer risk in the recessive and homozygote models (TT vs. CC: OR = 1.19, P = 0.01; TT vs. CT+CC: OR = 1.19, P <0.001). Furthermore, stratified analyses revealed a significant association between the rs1001179 polymorphism and prostate cancer in all models except the homozygote comparison. An association of the rs794316 polymorphism with cancer risk was detected in two genetic models (TT vs. AA: OR = 1.34, 95% CI = 1.03-1.74, P <0.001; TT vs. AT+AA: OR = 1.39, 95% CI = 1.09-1.77, P = 0.01). Additional well-designed studies with large samples should be performed to validate our results.

Association between heme oxygenase-1 gene promoter polymorphisms and cancer susceptibility: A meta-analysis

Numerous studies have focused on the association between heme oxygenase-1 (HO-1) gene promoter polymorphisms and susceptibility to cancer; however, results remain ambiguous. The present systematic Human Genome Epidemiology review and meta-analysis aimed to clarify this association. A systematic search was used to assess the association of HO-1 gene polymorphisms with cancer susceptibility in the PubMed, Web of Science, Cochrane Library, Wanfang Data and China National Knowledge Infrastructure databases, with all reviewed studies published before April 10, 2017. Review Manager 5.3 and Stata 12.0 software were used to perform the meta-analysis. A total of 14 studies were included in the analysis. Overall, no significant associations of the HO-1 (GT)n and T(−413)A polymorphisms with cancer susceptibility were identified. However, subgroup analyses by ethnicity and cancer type indicated that the LL and L-allele (LL+LS) genotypes of HO-1 (GT)n were associated with increased susceptibility to cancer compared with the SS+SL and SS genotypes in the following subgroups: East Asian [LL+LS vs. SS: odds ratio (OR)=1.51, 95% confidence interval (CI)=1.11–2.05, P=0.0003; LL vs. SS+SL: OR=1.44, 95% CI=1.04–2.01, P=0.03; LL vs. SS: OR=1.64, 95% CI=1.07–2.52, P=0.02]; squamous cell carcinoma (LL+LS vs. SS: OR=1.78, 95% CI=1.35–2.34, P<0.05; LL vs. SS+SL: OR=1.71, 95% CI=1.34–2.18, P<0.05; LL vs. SS: OR=2.26, 95% CI =1.62–3.14, P<0.05); and digestive tract cancer + East Asian (LL+LS vs. SS: OR=1.56, 95% CI=1.22–1.98, P<0.05; LL vs. SS: OR=1.80, 95% CI=1.06–3.05, P<0.05). These findings indicated that there was no association of the HO-1 (GT)n and T(−413)A polymorphisms with cancer susceptibility, while the L-allele genotypes (LL and LS) of HO-1 (GT)n may be susceptibility factors for cancer in East Asian, digestive tract cancer in East Asian and squamous cell carcinoma populations. Due to limitations of the reviewed studies, additional large-scale and refined studies are now required to confirm the present findings.

Association between MPO-463G > A polymorphism and cancer risk: evidence from 60 case-control studies

BACKGROUND

Though a number of studies have been conducted to explore the association between myeloperoxidase (MPO)-463G > A polymorphism and cancer risk, the results remain inconsistent. Therefore, we performed a meta-analysis to derive a more systematic estimation of this relationship.

METHOD

Relevant studies were searched by PubMed, EMBASE, CNKI, Google Scholar, Ovid, and Cochrane library prior to December 2015. The strength of the association between MPO-463G > A polymorphism and cancer risk was estimated by odds ratios (OR) with 95% confidence interval (95%CI). Cumulative analysis was used to evaluate the stability of results through time.

RESULTS

The current analysis consisted of 16,858 cases and 21,756 controls from 60 studies. Pooled results showed that MPO-463G > A polymorphism were associated with the overall decreased cancer susceptibility in all the genetic models included in this study (additive model: OR = 0.84, 95%CI = 0.76-0.94; allele genetic model: OR = 0.90, 95%CI = 0.840-0.954; recessive genetic model: OR = 0.89, 95%CI = 0.83-0.95). However, in the stratified analysis of cancer type, the significant results were only found in lung cancer (dominant model: OR = 0.93, 95%CI = 0.87-0.99) and digestive system cancer groups (dominant model: OR = 0.67 0.53-0.84; allele frequency model = 0.71, 95%CI = 0.57-0.87), but not in the blood system cancer or breast cancer group. When we further stratified the digestive system cancer group into digestive tract and digestive gland cancer groups, results showed a significant association between allele A of MPO-463G > A and digestive gland cancer in all the genetic models (allele frequency model: OR = 0.63, 95%CI = 0.40-0.99; additive model: OR = 0.41, 95%CI = 0.23-0.73; recessive model: OR = 0.51, 95%CI = 0.29-0.89; dominant model: OR = 0.58, 95%CI = 0.35-0.96), digestive tract cancers in allele frequency model (OR = 0.75, 95%CI = 0.59-0.95), and dominant model (OR = 0.72, 95%CI = 0.56-0.92). When stratified by ethnicity, results demonstrated that the genotype A might be a protect factor for both Caucasians and Asians. In group analysis according to source of controls, significant results were found in population from hospital in all the genetic models. In cumulative analysis, result of allele contrast showed a declining trend and increasingly narrower 95% overall, while the inclination toward non-significant association with lung cancer risk.

CONCLUSIONS

This meta-analysis suggested that MPO-463G > A polymorphism was associated with the overall reduced cancer susceptibility significantly. It might be a more reliable predictor of digestive system cancer instead of lung cancer, blood system cancer, and breast cancer. In cumulative analysis, the stable trend indicated that evidence was sufficient to show the association between MPO-463G > A polymorphism and cancer risk.

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.

The Role of Catalase C262T Gene Polymorphism in the Susceptibility and Survival of Cancers

Catalase (CAT), one antioxidant enzyme, may provide resistance against many diseases. Many previous studies reported predictive and prognostic values of CAT C262T polymorphism in cancers, with divergent results. This study aimed to summarize the overall relationships between CAT C262T polymorphism and cancer risk or survival. A total of 27 eligible publications were included in susceptibility analysis, while 8 publications contained survival outcomes. The results revealed significant relationship between CAT C262T polymorphism and cancer risk(TT + CT vs CC: OR = 1.05, 95%CI = 1.00–1.10, P = 0.036), subgroup analyses indicated the CAT C262T polymorphism was significantly correlated with an increased risk for prostate cancer (TT vs CC + CT: OR = 1.43, 95%CI = 1.20–1.70, P < 0.001) and increased risk among Caucasians (TT vs CC + CT: OR = 1.19, 95%CI = 1.09–1.31, P < 0.001), while no associations between the polymorphism and Asian or mixed population were established. In the survival analysis, no interactions were identified between this polymorphism and cancer survival (TT + CT vs CC: HR = 1.37, 95%CI = 0.70–2.70, P = 0.36). In conclusion, the CAT C262T polymorphismmay be a candidate markerfor cancer risk with type-specific and population-specific effects but not a fine prognostic factor for cancer survival.

Association of Catalase and Glutathione Peroxidase 1 Polymorphisms with Chronic Hepatitis C Outcome

The hepatic damage caused by hepatitis C virus (HCV) infection is associated with the host immune response and viral regulatory factors. Catalase (CAT) and glutathione peroxidase 1 (GPX1) are antioxidant enzymes located in the peroxisomes and mitochondria, respectively, and are responsible for the control of intracellular hydrogen peroxide levels. Polymorphisms in CAT (C-262T) and GPX1 (Pro198Leu) are correlated with serum levels and enzyme activity. This study aimed to investigate the association of genetic polymorphisms of CAT C-262T (rs1001179) and GPX1 Pro198Leu (rs1050450) with different stages of liver fibrosis and development of hepatocellular carcinoma (HCC). This study included 445 patients with chronic hepatitis C, of whom 139 patients had mild fibrosis (F0-F1), 200 had moderate/severe fibrosis (F2-F4), and 106 had HCC. Genotyping of SNPs was performed by real-time PCR using TaqMan probes. The Pro/Pro genotype of GPX1 was significantly associated with fibrosis severity, HCC, Child Pugh score, and BCLC staging. Additionally, patients carrying both CT+TT genotypes in the CAT gene and the Pro/Pro genotype in the GPX1 gene had higher risk for developing moderate/severe fibrosis or HCC (p = 0.009, OR 2.40 and p = 0.002, OR 3.56, respectively). CAT and GPX1 polymorphisms may be implicated in the severity of liver fibrosis and HCC caused by HCV.

G894T and 4a/b polymorphisms of NOS3 gene are not associated with cancer risk: a meta-analysis

Endothelial nitric oxide synthase (eNOS or NOS3) produces nitric oxide and genetic polymorphisms of NOS3 gene play significant roles in various processes of carcinogenesis. The results from published studies on the association between NOS3 G894T and NOS3 intron 4 (4a/b) polymorphisms and cancer risk are conflicting and inconclusive. However, i n order to assess this relationship more precisely, a meta-analysis was performed with PubMed (Medline), EMBASE and Google web searches until February 2014 to select all published case- control and cohort studies. Genotype distribution data were collected to calculate the pooled odd ratios (ORs) and 95% confidence intervals (CIs) to evaluate the strength of association. A total of 10,546 cancer cases and 10,550 controls were included from twenty four case-control studies for the NOS3 G894T polymorphism. The results indicated no significant association with cancer risk as observed in allelic (T vs G: OR=1.024, 95%CI=0.954 to 1.099, p=0.508), homozygous (TT vs GG: OR=1.137, 95%CI=0.944 to 1.370, p=0.176), heterozygous (GT vs GG: OR=0.993, 95%CI=0.932 to 1.059, p=0.835), recessive (TT vs GG+GT: OR=1.100, 95%CI=0.936 to 1.293, p=0.249) and dominant (TT+GT vs GG: OR=1.012, 95%CI=0.927 to 1.105, p=0.789) genetic models. Similarly, a total of 3,449 cancer cases and 3,691 controls were recruited from fourteen case-control studies for NOS3 4a/b polymorphism. Pooled results indicated no significant association under allelic (A vs B: OR=0.981, 95%CI=0.725 to 1.329, p=0.902), homozygous (AA vs BB: OR=1.166, 95%CI=0.524 to 2.593, p=0.707), heterozygous (BA vs BB: OR=1.129, 95%CI=0.896 to 1.422, p=0.305), dominant (AA+BA vs BB: OR=1.046, 95%CI=0.779 to 1.405, p=0.763) and recessive (AA vs BB+BA: OR=1.196, 95%CI=0.587 to 2.439, p=0.622) genetic contrast models. This meta-analysis suggests that G894T and 4a/b polymorphisms of NOS3 gene are not associated with increased or decreased risk of overall cancer.

A Single Nucleotide Polymorphism in Catalase Is Strongly Associated with Ovarian Cancer Survival

Ovarian cancer is the deadliest of all gynecologic cancers. Recent evidence demonstrates an association between enzymatic activity altering single nucleotide polymorphisms (SNP) with human cancer susceptibility. We sought to evaluate the association of SNPs in key oxidant and antioxidant enzymes with increased risk and survival in epithelial ovarian cancer. Individuals (n = 143) recruited were divided into controls, (n = 94): healthy volunteers, (n = 18), high-risk BRCA1/2 negative (n = 53), high-risk BRCA1/2 positive (n = 23) and ovarian cancer cases (n = 49). DNA was subjected to TaqMan SNP genotype analysis for selected oxidant and antioxidant enzymes. Of the seven selected SNP studied, no association with ovarian cancer risk (Pearson Chi-square) was found. However, a catalase SNP was identified as a predictor of ovarian cancer survival by the Cox regression model. The presence of this SNP was associated with a higher likelihood of death (hazard ratio (HR) of 3.68 (95% confidence interval (CI): 1.149–11.836)) for ovarian cancer patients. Kaplan-Meier survival analysis demonstrated a significant median overall survival difference (108 versus 60 months, p<0.05) for those without the catalase SNP as compared to those with the SNP. Additionally, age at diagnosis greater than the median was found to be a significant predictor of death (HR of 2.78 (95% CI: 1.022–7.578)). This study indicates a strong association with the catalase SNP and survival of ovarian cancer patients, and thus may serve as a prognosticator.

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.

eNOS Genetic Polymorphisms and Cancer Risk: A Meta-Analysis and a Case-Control Study of Breast Cancer

The association between endothelial nitric oxide synthase (eNOS) polymorphisms (intron 4a/b, -786T>C and 894G>T) and cancer risk remains elusive. In addition, no studies focused on their associations with the risk of breast cancer in Chinese Han population. Thus, a meta-analysis was conducted to determine the relationship between eNOS polymorphisms and cancer risk, and then a case-control study in Chinese Han population was performed to assess their associations with breast cancer susceptibility.Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association. The pooled analysis indicated that eNOS intron 4a/b and -786T>C polymorphisms were significantly associated with an increased risk of overall cancer. In subgroup analyses based on cancer type, the significant association was found between eNOS intron 4a/b polymorphism and prostate cancer risk, eNOS -786T>C polymorphism and risk of prostate, bladder and breast cancers, and eNOS 894G>T polymorphism and breast cancer risk. In subgroup analyses based on ethnicity, eNOS intron 4a/b and -786T>C polymorphisms were associated with an increased risk of cancer in Caucasians. In consistent with our meta-analysis results, a case-control study in Chinese Han population showed significant associations of eNOS -786T>C and 894G>T polymorphisms with the increased risk of breast cancer. In addition, stratified analyses based on pathological type showed that eNOS 894G>T polymorphism was only associated with the risk of infiltrative ductal carcinoma. Stratified analyses by tumor stage showed that eNOS -786T>C polymorphism was only associated with the risk of tumor stage III and IV.In conclusion, our meta-analysis and case-control study suggest that eNOS -786T>C and 894G>T polymorphisms are associated with the increased risk of breast cancer.

Association between three eNOS polymorphisms and cancer risk: a meta-analysis

Polymorphisms in the endothelial nitric oxide synthase (eNOS) gene may influence the risk of cancer, but the results are still debatable. Therefore, we performed a systematic review to provide a more complete picture and conducted a meta-analysis to derive a precise estimation. We searched PubMed, EMBASE, EBSCO, Google Scholar and China National Knowledge Infrastructure (CNKI) databases until April 2014 to identify eligible studies. Thirty-one studies with cancer patients and controls were included in the meta-analysis. Overall, the polled analysis revealed that the T-786C polymorphism was significantly associated with increased cancer risk under multiple genetic models (C vs T: OR=1.135, 95%CI=1.048-1.228; CC vs TT: OR=1.278, 95%CI=1.045- 1.562; TC vs TT: OR=1.136, 95%CI=1.023-1.261; CC+TC vs TT: OR=1.159, 95%CI=1.047-1.281; CC vs TC+TT: OR=1.204, 95%CI= 1.003-1.447). G894T was associated with significant risk for females (TT vs GG: OR=1.414, 95%CI=1.056-1.892; TT vs GT+GG: OR=1.356, 95%CI=1.108-1.661) and for breast cancer (T vs G: OR=1.097, 95%CI=1.001-1.203; TT vs GG: OR=1.346, 95%CI=1.012-1.789; TT vs GT+GG: OR=1.269, 95%CI=1.028-1.566). Increased susceptibility was revealed for prostate cancer with 4a/b (ba vs bb: OR=1.338, 95%CI=1.013-1.768; aa+ba vs bb: OR=1.474, 95%CI=1.002-2.170). This meta-analysis indicated that the eNOS T-786C polymorphism is associated with elevated cancer risk; the G894T polymorphism contributes to susceptibility to breast cancer and cancer generally in females; and the 4a/b polymorphism may be associated with prostate cancer risk.

The catalase C-262T gene polymorphism and cancer risk: a systematic review and meta-analysis

Many studies suggest that catalase C-262T gene polymorphism is associated with cancer risk, but with inconsistent results. This study aimed to summarize the overall association between catalase C-262T polymorphism and cancer risk. Literature search was performed in PubMed, Embase, and other databases, studies regarding the association between catalase C-262T polymorphism and cancer risk were identified, and data were retrieved and analyzed by using Review Manager 5.0.24 and STATA 12.0. A total of 18 publications with 22 case-control studies, including 9777 cancer patients and 12,223 controls, met the inclusion criteria. Meta-analysis results showed significant association between catalase C-262 T polymorphism and cancer risk (TT vs CT + CC: odds ratio [OR] = 1.17, 95% confidence interval [CI] = 1.03-1.31, P = 0.01). Subgroup analyses stratified by cancer types suggested the catalase C-262T polymorphism was significantly associated with an increased prostate cancer risk (TT vs CT + CC: OR = 1.61, 95% CI = 1.17-2.22, P = 0.004); for subgroup analyses stratified by ethnicity, no associations between this polymorphism and Asians or whites were identified (CT + TT vs CC: OR = 1.11, 95% CI = 0.98-1.26, P = 0.09 for whites; OR = 1.19, 95% CI = 0.78-1.80, P = 0.42 for Asians). In summary, the catalase C-262T polymorphism may be a risk factor for cancer with cancer type-specific effects. Further studies should be performed to confirm these findings.

Association between the (GT)n polymorphism of the HO-1 gene promoter region and cancer risk: a meta-analysis

BACKGROUND

Several studies have previously focused on associations between the (GT)n repeat polymorphism of the heme oxygenase-1 (HO-1) gene promoter region and risk of cancers, but results are complex. We conducted the present meta-analysis to integrate relevant findings and evaluate the association between HO-1 (GT)n repeat polymorphism and cancer susceptibility.

MATERIALS AND METHODS

Published literature was retrieved from the PubMed/MEDLINE, EMBASE and ISI Web of Science databases before November 2013. For all alleles and genotypes, odds ratios were pooled to assess the strength of the associations using either fixed-effects or random-effects models according to heterogeneity. Subgroup analysis was conducted according to ethnicity and histopathology.

RESULTS

A total of 10 studies involving 2,367 cases and 2,870 controls were identified. The results showed there was no association between HO-1 (GT)n repeat polymorphism and the cancer risk both at the allelic and genotypic level. However, in the stratified analysis, we observed an increased risk of squamous cell carcinoma in persons carrying the LL genotype and the LL+LS genotype as compared with those carrying the SS genotype. When the LS and SS genotypes were combined, the odds ratio for squamous cell carcinoma in LL-genotype carriers, were also significantly increased. No publication bias was observed.

CONCLUSIONS

The LL genotype and L-allele carrying genotypes (LL+LS) of HO-1 (GT)n repeat polymorphism are potential genetic factors for developing squamous cell carcinoma. More large and well-designed studies are required for further validations.

No association between HMOX1 and risk of colorectal cancer and no interaction with diet and lifestyle factors in a prospective Danish case-cohort study

Red meat is a risk factor for colorectal cancer (CRC). We wanted to evaluate whether a functional polymorphism in the HMOX1 gene encoding heme oxygenase modifies risk of CRC or interacts with diet or lifestyle factors because this would identify heme or heme iron as a risk factor of CRC. The HMOX1 A-413T (rs2071746) was assessed in relation to risk of colorectal cancer (CRC) and interactions with diet (red meat, fish, fiber, cereals, fruit and vegetables) and lifestyle (use of non-steroidal anti-inflammatory drug and smoking status) were assessed in a case-cohort study of 928 CRC cases and a comparison group of 1726 randomly selected participants from a prospective study of 57,053 persons. No association between HMOX1 A-413T and CRC risk was found (TT vs. AA + TA; IRR = 1.15, 95% CI: 0.98-1.36, p = 0.10 for the adjusted estimate). No interactions were found between diet or lifestyle and HMOX1 A-413T. HMOX1 A-413T was not associated with CRC risk and no interactions with diet or lifestyle were identified in this large, prospective cohort with high meat intake. The results reproduced the previous findings from the same cohort and did not support a link between heme or heme iron and colorectal cancer. These results should be sought and replicated in other well-characterized cohorts with high meat intake.

The G894t, T-786c and 4b/a polymorphisms in Enos gene and cancer risk: a meta-analysis

OBJECTIVE

Published results on association between eNOS polymorphisms and cancer risk are conflicting. We aimed to investigate the association and give an overall understanding of possible risk role of eNOS.

METHOD

We searched PubMed and EMbase databases. The pooled ORs and 95% CIs for the association between eNOS polymorphisms and cancer risk was estimated using fixed- or random- effect model. Subgroup and sensitivity analyses were employed for further analysis.

RESULTS

The Overall results showed no significant association of G894T polymorphism with cancer susceptibility (T vs. G: OR 1.02, 95% CI 0.97 to 1.07; TT+GT vs. GG: OR 1.02, 95% CI 0.96 to 1.09; TT vs. GT+GG: OR 1.05, 95% CI 0.93 to 1.17). For the T-786C polymorphism, pooled OR under recessive model suggested that CC genotype was significantly associated with increased cancer risk (CC vs. TC+TT: OR 1.31, 95% CI 1.09 to 1.57). For the 4b/a polymorphism, pooled OR for recessive model suggested positive result of 4a/4a genotype (aa vs. ba+bb: OR 1.64, 95% CI 1.11 to 2.43). In subgroup analysis by ethnicity, significant association was found in Caucasians in recessive model but not in Asians for T-786C and 4b/a, respectively. In subgroup analysis by cancer types, significant result was obtained for breast cancer in recessive model for the T-786C polymorphism.

CONCLUSION

The eNOS G894T polymorphism may not be a major risk factor for most types of cancers. The CC of T-786C polymorphism and 4a/4a of 4b/a polymorphism are associated with cancer risk, especially in Caucasians. There is significant association between T786C polymorphism and breast cancer risk. More data are needed to verify these results.

Oxidative stress in susceptibility to breast cancer: study in Spanish population

Background

Alterations in the redox balance are involved in the origin, promotion and progression of cancer. Inter-individual differences in the oxidative stress regulation can explain a part of the variability in cancer susceptibility.

The aim of this study was to evaluate if polymorphisms in genes codifying for the different systems involved in oxidative stress levels can have a role in susceptibility to breast cancer.

Methods

We have analyzed 76 single base polymorphisms located in 27 genes involved in oxidative stress regulation by SNPlex technology. First, we have tested all the selected SNPs in 493 breast cancer patients and 683 controls and we have replicated the significant results in a second independent set of samples (430 patients and 803 controls). Gene-gene interactions were performed by the multifactor dimensionality reduction approach.

Results

Six polymorphisms rs1052133 (OGG1), rs406113 and rs974334 (GPX6), rs2284659 (SOD3), rs4135225 (TXN) and rs207454 (XDH) were significant in the global analysis. The gene-gene interactions demonstrated a significant four-variant interaction among rs406113 (GPX6), rs974334 (GPX6), rs105213 (OGG1) and rs2284659 (SOD3) (p-value = 0.0008) with high-risk genotype combination showing increased risk for breast cancer (OR = 1.75 [95% CI; 1.26-2.44]).

Conclusions

The results of this study indicate that different genotypes in genes of the oxidant/antioxidant pathway could affect the susceptibility to breast cancer. Furthermore, our study highlighted the importance of the analysis of the epistatic interactions to define with more accuracy the influence of genetic variants in susceptibility to breast cancer.

Genetic Polymorphism of CAT C-262 T and Susceptibility to Breast Cancer, a Case-Control Study and Meta-Analysis of the Literatures

Catalase (CAT) activity is likely to be affected by functional polymorphism of C-262 T (rs1001179) in the CAT gene (OMIM: 115500). It is hypothesized that individuals with the lower expressing forms of the CAT polymorphism may be more susceptible to breast cancer. Therefore, the present case-control study and meta-analysis were carried out. The present case-control study consisted of 407 females with breast cancer and a total of 395 healthy female from population matched with patients according to age. Genotypic analysis for the CAT C-262 T polymorphism was determined by PCR. We identified 7 eligible studies, including 10,471 subjects (4,959 patients, and 5,512 healthy controls) in relation to the CAT C-262 T polymorphism and breast cancer risk. Based on the present case-control study, the CT (OR = 0.90, 95% CI: 0.66-1.22, P = 0.484) and TT (OR = 0.68, 95% CI: 0.35-1.30, P = 0.245) genotypes were not associated with breast cancer risk compared to the CC genotype. For meta-analysis including all studies, there was significant heterogeneity between studies. The overall ORs of the breast cancer risk were not associated with the CT (Q-statistic = 14.90, df = 6, P < 0.05; OR = 1.01, 95% CI: 0.92-1.09, P = 0.862) and TT (Q-statistic = 2.57, df = 6, P > 0.05; OR = 1.03, 95% CI: 0.85-1.24, P = 0.770) genotypes. There was no association between C-262 T polymorphism of the CAT and risk of breast cancer.

Genetic Polymorphism of C-262T Catalase and Susceptibility to Schizophrenia

Background: Catalase (CAT, OMIM: 115500) plays an integral role in the primary defence against oxidative stress. The T allele of the C-262T CAT polymorphism (rs1001179) is associated with lower activity of CAT. Here we investigated whether polymorphism of C-266T CAT was associated with susceptibility to schizophrenia.Methods: The present study was performed on 363 (267 males, 96 females) in-patients with schizophrenia diagnosis, and a total of 363 (266 males, 97 females) healthy controls. The C-262T CAT genotypes were determined using RFLP-PCR method.Results: Although the association between genotypes and susceptibility was not significant in both genders, there was significant interaction between gender and the TT genotype (P=0.035). The Log-rank test and the Kaplan-Meier survival analysis were used to evaluate the influence of C-262T genotypes on age at diagnosis (AAD) of schizophrenia. Mean AAD of the CC and CT+TT genotypes in males was 22.8 and 24.9 years, respectively. The difference was significant (c2=4.26, P=0.039). Difference of mean AAD of the CC (26.7 years) and CT+TT (27.3 years) genotypes among females was not significant (c2=0.02, P=0.896).Conclusion: Different associations between gender groups might be at least in part interpreted by the effect of gender on the association between C-262T polymorphism and CAT gene expression.

Polymorphisms in metabolism/antioxidant genes may mediate the effect of dietary intake on pancreatic cancer risk

OBJECTIVES

A source of variation for inconsistent dietary-pancreatic cancer associations may be individuals carrying constitutional metabolism/antioxidant gene variants that differentially benefit compared to homozygous individuals. Seventy-six tag single-nucleotide polymorphisms were genotyped in 13 candidate genes to test differential associations with pancreatic adenocarcinoma.

METHODS

A clinic-based case-control design was used to rapidly ascertain 251 cases and 970 frequency matched controls who provided blood samples and completed a 144-item food frequency questionnaire. Single-nucleotide polymorphisms were evaluated using a dominant genetic model and dietary categories split on controls' median intake. Logistic regression was used to calculate odds ratios and 95% confidence intervals, adjusted for potential confounders.

RESULTS

Significant increased associations (Bonferroni corrected P ≤ 0.0007) were observed for carriers of greater than or equal to 1 minor allele for rs3816257 (glucosidase, α; acid [GAA]) and lower intake of deep-yellow vegetables (1.90 [1.28-2.83]); and carriers of no minor allele for rs12807961 (catalase [CAT]) and high total grains intake (2.48 [1.50-4.09]), whereas those with greater than or equal to 1 minor allele had a decreasing slope (across grains). The reference group was no minor alleles with low dietary intake.

CONCLUSIONS

Interindividual variation in metabolism/antioxidant genes could interact with dietary intake to influence pancreatic cancer risk.

Myeloperoxidase polymorphism, menopausal status, and breast cancer risk: an update meta-analysis

Myeloperoxidase (MPO) is a metabolic/oxidative lysosomal enzyme secreted by reactive neutrophils at the sites of inflamed organs and tissues during phagocytosis. MPO has been either directly or indirectly linked to neoplasia, which is a well-established risk factor for many types of cancer. A large number of studies have reported the role of MPO G-463A polymorphism regarding breast-cancer risk. However, the published findings are inconsistent. Therefore, we conducted a meta-analysis to determine more precise estimations for the relationship. Eligible studies were identified by searching several electronic databases for relevant reports published before June 2012. According to the inclusion criteria and exclusion criteria, a total of five eligible studies were included in the pooled analyses. When the five eligible studies concerning MPO G-463A polymorphism were pooled into this meta-analysis, there was no evidence found for a significant association between MPO G-463A polymorphism and breast-cancer risk in any genetic model. We also categorized by ethnicity (Caucasian or Asian) for subgroup analysis; according to this subgroup analysis, we found no significant association between MPO G-463A polymorphism and breast-cancer risk in any genetic model. However, in the stratified analysis for the premenopausal group, women carrying the AA genotype were found to have a significantly reduced risk (OR = 0.56, 95% CI 0.34-0.94, p = 0.027). Under the recessive model, there was a significant association between MPO G-463A polymorphism and breast-cancer risk (OR = 0.57, 95% CI 0.34-0.93, p = 0.025). We conclude that MPO-G463A polymorphism might not be a good predictor of breast-cancer risk, though menopausal status modified women's risk of developing breast cancer.

Menopausal status modifies breast cancer risk associated with ESR1 PvuII and XbaI polymorphisms in Asian women: a HuGE review and meta-analysis

BACKGROUND

Published data on the association between single nucleotide polymorphisms (SNPs) in the ESR1 gene and breast cancer susceptibility are inconclusive or controversial. The aim of this Human Genome Epidemiology (HuGE) review and meta-analysis was to derive a more precise estimation of this relationship.

METHODS

A literature search of Pubmed, Embase, Web of science and CBM databases was conducted from inception through September 1 th, 2012. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association.

RESULTS

A total of five studies including 1,678 breast cancer cases and 1,678 general population controls in Asian populations were involved in this meta-analysis. When all the eligible studies were pooled into the meta-analysis, the higher transcriptional activity variant allele T of ESR1 PvuII (C>T) (rs2234693) in pre-menopausal breast cancer women showed a significant relation to increased risk (OR = 1.13, 95%CI: 1.01-1.28, P = 0.040) in contrast to their post-menopausal counterparts which showed non-significant increased risk (OR = 1.01, 95%CI: 0.87-1.18, P = 0.858). Nevertheless, no significant association between ESR1 XbaI (A>G) (rs9340799) polymorphism and the risk of breast cancer was observed in pre-menopausal and post-menopausal individuals.

CONCLUSION

Based on a homogeneous Asian population, results from the current meta-analysis indicates that the ESR1 PvuII (C>T) polymorphism places pre-menopausal breast cancer women at risk for breast cancer, while ESR1 XbaI (A>G) polymorphism is not likely to predict the risk of breast cancer.

Association of the -262C/T polymorphism in the catalase gene promoter and the C242T polymorphism of the NADPH oxidase P22phox gene with essential arterial hypertension in patients with diabetes mellitus type 2

AIM

The aim of the present study was to test the association between genetic polymorphisms with functional effects on redox regulation: the -262C/T of the catalase gene promoter (rs1001179), the C242T of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase P22phox gene (rs4673), and the 594C/T polymorphism of the glutathione peroxidase gene (rs1050450) and arterial hypertension (AH) in patients with type 2 diabetes.

METHODS

810 Slovenian subjects (Caucasians) with type 2 diabetes were enrolled in the cross-sectional study. Genotypes were determined by real-time PCR.

RESULTS

Univariate analysis failed to demonstrate an association between either the -262C/T of the catalase gene promoter (rs1001179) or the C242T polymorphism of the P22phox gene (rs4673) or the 594C/T polymorphism of the glutathione peroxidase gene (rs1050450) and AH. After adjustment for age, body mass index, fibrinogen level and high sensitivity C-reactive protein level, rs4673 was found to be an independent risk factor for AH in subjects with type 2 diabetes, whereas rs1001179 and rs1050450 were not.

CONCLUSION

According to the results of cross-sectional study, the tested polymorphism of the NADPH oxidase P22phox gene (rs4673) was found to be associated with the development of AH, indicating that the oxidative stress gene NADPH oxidase might be implicated in the pathogenesis of AH in subjects with type 2 diabetes.

Oxidative stress specifically downregulates survivin to promote breast tumour formation

Background:

Breast cancer, a heterogeneous disease has been broadly classified into oestrogen receptor positive (ER+) or oestrogen receptor negative (ER−) tumour types. Each of these tumours is dependent on specific signalling pathways for their progression. While high levels of survivin, an anti-apoptotic protein, increases aggressive behaviour in ER− breast tumours, oxidative stress (OS) promotes the progression of ER+ breast tumours. Mechanisms and molecular targets by which OS promotes tumourigenesis remain poorly understood.

Results:

DETA-NONOate, a nitric oxide (NO)-donor induces OS in breast cancer cell lines by early re-localisation and downregulation of cellular survivin. Using in vivo models of HMLE^HRAS xenografts and E2-induced breast tumours in ACI rats, we demonstrate that high OS downregulates survivin during initiation of tumourigenesis. Overexpression of survivin in HMLE^HRAS cells led to a significant delay in tumour initiation and tumour volume in nude mice. This inverse relationship between survivin and OS was also observed in ER+ human breast tumours. We also demonstrate an upregulation of NADPH oxidase-1 (NOX1) and its activating protein p67, which are novel markers of OS in E2-induced tumours in ACI rats and as well as in ER+ human breast tumours.

Conclusion:

Our data, therefore, suggest that downregulation of survivin could be an important early event by which OS initiates breast tumour formation.

Polymorphisms in oxidative stress genes, physical activity, and breast cancer risk

PURPOSE

The mechanisms driving the physical activity-breast cancer association are unclear. Exercise both increases reactive oxygen species production, which may transform normal epithelium to a malignant phenotype, and enhances antioxidant capacity, which could protect against subsequent oxidative insult. Given the paradoxical effects of physical activity, the oxidative stress pathway is of interest. Genetic variation in CAT or antioxidant-related polymorphisms may mediate the physical activity-breast cancer association.

METHODS

We investigated the main and joint effects of three previously unreported polymorphisms in CAT on breast cancer risk. We also estimated interactions between recreational physical activity (RPA) and 13 polymorphisms in oxidative stress-related genes. Data were from the Long Island Breast Cancer Study Project, with interview and biomarker data available on 1,053 cases and 1,102 controls.

RESULTS

Women with ≥1 variant allele in CAT rs4756146 had a 23 % reduced risk of postmenopausal breast cancer compared with women with the common TT genotype (OR = 0.77; 95 % CI = 0.59-0.99). We observed two statistical interactions between RPA and genes in the antioxidant pathway (p = 0.043 and 0.006 for CAT and GSTP1, respectively). Highly active women harboring variant alleles in CAT rs1001179 were at increased risk of breast cancer compared with women with the common CC genotype (OR = 1.61; 95 % CI, 1.06-2.45). Risk reductions were observed among moderately active women carrying variant alleles in GSTP1 compared with women homozygous for the major allele (OR = 0.56; 95 % CI, 0.38-0.84).

CONCLUSIONS

Breast cancer risk may be jointly influenced by RPA and genes involved in the antioxidant pathway, but our findings require confirmation.

Common polymorphisms in angiogenesis

A wide variety of diseases have a significant genetic component, including major causes of morbidity and mortality in the western world. Many of these diseases are also angiogenesis dependent. In humans, common polymorphisms, although more subtle in effect than rare mutations that cause Mendelian disease, are expected to have greater overall effects on human disease. Thus, common polymorphisms in angiogenesis-regulating genes may affect the response to an angiogenic stimulus and thereby affect susceptibility to or progression of such diseases. Candidate gene studies have identified several associations between angiogenesis gene polymorphisms and disease. Similarly, emerging pharmacogenomic evidence indicates that several angiogenesis-regulating polymorphisms may predict response to therapy. In contrast, genome-wide association studies have identified only a few risk alleles in obvious angiogenesis genes. As in other traits, regulatory polymorphisms appear to dominate the landscape of angiogenic responsiveness. Rodent assays, including the mouse corneal micropocket assay, tumor models, and a macular degeneration model have allowed the identification and comparison of loci that directly affect the trait. Complementarity between human and animal approaches will allow increased understanding of the genetic basis for angiogenesis-dependent disease.

Long-term vegetarians have low oxidative stress, body fat, and cholesterol levels

Excessive oxidative stress and abnormal blood lipids may cause chronic diseases. This risk can be reduced by consuming an antioxidant- and fiber-rich vegetarian diet. We compared biomarkers of oxidative stress, antioxidant capacity, and lipid profiles of sex- and age-matched long-term vegetarians and omnivores in Korea. Forty-five vegetarians (23 men and 22 women; mean age, 49.5 ± 5.3 years), who had maintained a vegetarian diet for a minimum of 15 years, and 30 omnivores (15 men and 15 women; mean age, 48.9 ± 3.6 years) participated in this study. Their 1-day, 24-h recall, and 2-day dietary records were analyzed. Oxidative stress was measured by the levels of diacron reactive oxygen metabolites (d-ROM). Antioxidant status was determined by the biological antioxidant potential (BAP) and levels of endogenous antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. We observed that vegetarians had a significantly lower body fat percentage (21.6 ± 6.4%) than that of omnivores (25.4 ± 4.6%; P < 0.004). d-ROM levels were significantly lower in vegetarians than those in omnivores (331.82 ± 77.96 and 375.80 ± 67.26 Carratelli units; P < 0.011). Additionally, total cholesterol levels in the vegetarians and omnivores were 173.73 ± 31.42 mg/dL and 193.17 ± 37.89 mg/dL, respectively (P < 0.018). Low-density lipoprotein cholesterol was 101.36 ± 23.57 mg/dL and 120.60 ± 34.62 mg/dL (P < 0.005) in the vegetarians and omnivores, respectively, indicating that vegetarians had significantly lower lipid levels. Thus, oxidative stress, body fat, and cholesterol levels were lower in long-term vegetarians than those in omnivores.

Menopausal status modifies breast cancer risk associated with the myeloperoxidase (MPO) G463A polymorphism in Caucasian women: a meta-analysis

Background

Breast cancer susceptibility may be modulated partly through polymorphisms in oxidative enzymes, one of which is myeloperoxidase (MPO). Association of the low transcription activity variant allele A in the G463A polymorphism has been investigated for its association with breast cancer risk, considering the modifying effects of menopausal status and antioxidant intake levels of cases and controls.

Methodology/Principal Findings

To obtain a more precise estimate of association using the odds ratio (OR), we performed a meta-analysis of 2,975 cases and 3,427 controls from three published articles of Caucasian populations living in the United States. Heterogeneity among studies was tested and sensitivity analysis was applied. The lower transcriptional activity AA genotype of MPO in the pre-menopausal population showed significantly reduced risk (OR 0.56–0.57, p = 0.03) in contrast to their post-menopausal counterparts which showed non-significant increased risk (OR 1.14; p = 0.34–0.36). High intake of antioxidants (OR 0.67–0.86, p = 0.04–0.05) and carotenoids (OR 0.68–0.86, p = 0.03–0.05) conferred significant protection in the women. Stratified by menopausal status, this effect was observed in pre-menopausal women especially those whose antioxidant intake was high (OR 0.42–0.69, p = 0.04). In post-menopausal women, effect of low intake elicited susceptibility (OR 1.19–1.67, p = 0.07–0.17) to breast cancer.

Conclusions/Significance

Based on a homogeneous Caucasian population, the MPO G463A polymorphism places post-menopausal women at risk for breast cancer, where this effect is modified by diet.

Common genetic variants in the myeloperoxidase and paraoxonase genes and the related cancer risk: a review

Modern approaches in health care are moving toward the model of "personalized medicine." Today, current research in molecular biology and medicine is focused on developing genomic markers with predictive, therapeutic, and prognostic significance. One of the most widespread and significant genomic markers is the single nucleotide polymorphism (SNP), which represents a variation in DNA sequence when a single nucleotide differs between members of a biological species or paired chromosomes in an individual. Antioxidant defense enzymes break down dangerous reactive compounds, called reactive oxygen species, and prevent DNA strand from carcinogen-specific mutations. It is well known that inherited variations in genes that encode antioxidant defense enzymes may modulate individual susceptibility to cancer. In our previous study we have determined the predictive significance of several SNPs of superoxide dismutase (SOD) and glutathione peroxidase gene families in the context of cancer risk. The present review includes a summary and discussion of the current findings evaluating the role of SNPs of the myeloperoxidase (MPO) and paraoxanase (PON) genes in cancer occurrence and development. We suggest that rs2333227 (MPO_ -463G/A) and rs854560 polymorphisms have a great predictive significance; they could probably be utilized as cancer predictors in the future. Also, we recommend further in-depth research for rs11079344 (MPO), rs8178406 (MPO), rs2243828 (MPO), rs662 (PON1), rs705379 (PON1), and PON1_304A/G polymorphisms. These SNPs may become significant cancer-associated biomarkers.

Nutrigenomics: implications for breast and colon cancer prevention

Nutrigenomics refers to the interaction between one's diet and his/her genes. These interactions can markedly influence digestion, absorption, and the elimination of bioactive food components, as well as influence their site of actions/molecular targets. Nutrigenomics comprises nutrigenetics, epigenetics, and transcriptomics, coupled with other "omic," such as proteomics and metabolomics, that apparently account for the wide variability in cancer risk among individuals with similar dietary habits. Multiple food components including essential nutrients, phytochemical, zoochemicals, fungochemical, and bacterochemicals have been implicated in cancer risk and tumor behavior, admittedly with mixed results. Such findings suggest that not all individuals respond identically to a diet. This chapter highlights the influence of single-nucleotide polymorphism, copy number, epigenetic events, and transcriptomic homeostasis as factors influencing the response to food components and ultimately health, including cancer risk. Both breast and colorectal cancers are reviewed as examples about how nutrigenomics may influence the response to dietary intakes. As the concept that "one size fits all" comes to an end and personalized approaches surface, additional research data will be required to identify those who will benefit most from dietary change and any who might be placed at risk because of an adjustment.

Oxidative stress-related enzyme gene polymorphisms and susceptibility to breast cancer in non-smoking, non-alcohol-consuming Taiwanese women: a case-control study

BACKGROUND

Mitochondrial manganese superoxide dismutase (MnSOD) converts superoxide anion into H(2)O(2), which is neutralized sequentially by either catalase (CAT) or glutathione peroxidase 1 (Gpx 1) into water or converted into highly reactive hypochlorous acid by myeloperoxidase (MPO). We hypothesize that gene variants for these enzymes might be associated with the risk of breast cancer in non-smoking, non-alcohol-consuming women.

METHODS

Genotypes of oxidative stress-related enzymes (MnSOD1183T>C, MPO-463G>A, GPx1Pro198Leu and CAT-262C>T) were analysed in 260 non-smoking and non-alcohol-consuming female patients with breast cancer and 224 habit-matched controls.

RESULTS

Subjects with the MnSOD1183T>C C carrier or those with the GPx1Pro198Leu CT genotype had significantly decreased age-adjusted risks (odds ratio [OR]: 0.56 and 0.16 with 95% confidence intervals [95% CI]: 0.38-0.83 and 0.08-0.29, respectively) for breast cancer. Certain combined genotypes of the polymorphisms also significantly modulated the age-adjusted risk.

CONCLUSIONS

We conclude that oxidative stress-related enzyme genetic variants, especially GPx1Pro198Leu CT, modify the risk of breast cancer development in non-smoking and non-alcohol-consuming women. The role of unidentified environmental factors predisposing to breast cancer development through an oxidative stress mechanism merits further investigation.

Serum total oxidant/antioxidant status and trace element levels in breast cancer patients

BACKGROUND

Oxidative stress and trace elements have been implicated in the development of breast cancer. However, how they contribute to the pathogenesis of the disease and the relationship between them remain unclear. In addition, most previous studies detecting one or a few oxidant/antioxidant markers failed to consider the overall oxidant/antioxidant status of the subjects. This study was designed to address this and to investigate the association between oxidative status and trace elements in the pathogenesis of breast cancer.

METHODS

Fifty-six patients with breast carcinoma at different clinical stages, 32 patients with benign breast tumor, and 20 healthy subjects (controls) were recruited into this study. Their serum total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and levels of Cu, Zn, Fe, Se, Mg, and Mn were measured.

RESULTS

Levels of TAS, TOS, OSI, and trace elements significantly differed between the study groups. Among subgroups of patients with different clinical stages of breast cancer, the levels of all the trace elements except Zn were similar, whereas TAS, TOS, and OSI levels were all significantly different. There were significant correlations between oxidative stress parameters and levels of trace elements in patients with breast carcinoma but not in patients with benign breast tumor or in the healthy controls.

CONCLUSIONS

Disturbed oxidative stress status and trace element levels may contribute to the pathogenesis of breast tumors. TAS, TOS, and OSI may be useful biomarkers for monitoring the clinical status of breast cancer.

Genetic variation in myeloperoxidase modifies the association of serum α-tocopherol with aggressive prostate cancer among current smokers

We investigated associations of serum α- and γ-tocopherols and their effect modification by polymorphisms in oxidative stress regulatory enzymes in relation to prostate cancer risk. In a nested case-control study in the Carotene and Retinol Efficacy Trial, prerandomized serum α- and γ-tocopherol were assayed among 684 men with incident prostate cancer [375 nonaggressive and 284 aggressive cancer (stage III/IV or Gleason score ≥7)] and 1441 controls. Manganese superoxide dismutase Ala-16Val (rs4880), glutathione peroxidase 1 Pro200Leu (rs1050450), catalase -262 C > T (rs1001179), and myeloperoxidase (MPO) G-463A (rs2333227) were genotyped. A multivariate-adjusted inverse association of serum α-tocopherol with total prostate cancer risk was observed in current smokers (OR = 0.62, 95% CI = 0.40-0.96, 4th vs. 1st quartiles). High (≥median) compared to low serum concentrations of α- and γ-tocopherol were inversely associated with aggressive prostate cancer in current smokers (OR = 0.50, 95% CI = 0.32-0.78 and OR = 0.64, 95% CI = 0.43-0.95, respectively). The association was stronger among those with MPO G/A+A/A genotypes. Among current smokers with low serum α-tocopherol concentrations, MPO G/A+A/A, the genotypes downregulating oxidative stress, were associated with an increased risk for aggressive prostate cancer (OR = 2.06, 95% CI = 1.22-3.46). Conversely, current smokers with these genotypes who had high α-tocopherol concentrations had a reduced risk for aggressive prostate cancer (OR = 0.34, 95% CI = 0.15-0.80; P-interaction = 0.001). In conclusion, among current smokers, both high serum α- and γ-tocopherol concentrations were associated with reduced risks of aggressive prostate cancer. The α-tocopherol-associated risks are modified by polymorphism in MPO G-463A.

Combined effects of antioxidant vitamin and NOS3 genetic polymorphisms on breast cancer risk in women

BACKGROUND & AIMS

It is becoming increasingly clear that there is wide heterogeneity in genetic predisposition to breast cancer and that breast cancer risk is determined by interactive effect between genetic and environmental factors.

METHODS

We investigated the combined effects of antioxidant vitamin intake and NOS3 genetic polymorphisms on breast cancer risk in a Korean population (Seoul Breast Cancer Study). Histologically confirmed breast cancer cases (n = 512) and age, menopause status-matched controls (n = 512) with no present or previous history of cancer were recruited from several teaching hospitals in Seoul during 2001-2003. Two genetic polymorphisms of NOS3 (298G > T and -786 T > C) were assessed by single base extension assays.

RESULTS

No overall association between the individual NOS3 genotypes or diplotypes and breast cancer risk was found, although the difference between cases and controls in the frequency of the NOS3 894 G > T polymorphism showed borderline significance (OR = 0.74, 95% CI = 0.52-1.06). There was no significant difference in energy intake or the intake of antioxidant vitamins between cases and controls, with the exception of vitamin E (OR = 0.49 lowest vs. highest quartile, P(trend) < 0.01). On the other hand, our results suggest that antioxidant vitamin intake may modify the effects of the NOS3 -786 T > C or 894 G > T genetic polymorphisms on breast cancer risk. Although a multiplicative interaction was not observed, the protective effect of β-carotene intake on breast cancer risk was observed predominantly in individuals with the TG:TG diplotype of NOS3 (OR = 0.68) but not observed with others diplotype. An inverse association between vitamin E intake and breast cancer risk was observed for individuals with the NOS3 786 TC + TT genotype and the NOS3 894 GG genotype. In addition, folic acid had a protective effect in the NOS3 786 TT and NOS3 894 GT + TT genotype.

CONCLUSION

Our results suggest that intake of antioxidant vitamins might modify the association between genetic polymorphisms of NOS3 and breast cancer risk.

Association of the −262C/T polymorphism in the catalase gene promoter with carotid atherosclerosis in Slovenian patients with type 2 diabetes

Genetic variations of the antioxidant enzymes may influence the susceptibility to oxidative stress and consequently the development and progression of diabetic complications. The aim of the current study was to test the association between the −262C/T polymorphism in the catalase gene promoter and carotid atherosclerosis in Slovenian patients with type 2 diabetes. Two-hundred and eighty six diabetics and 150 healthy controls were enrolled in the study. Carotid atherosclerosis was quantified ultrasonographiocally by carotid intima-media thickness (CITM), plaque score and plaque type. Genotypes were determined using the real-time PCR. Fibrinogen concentration showed a borderline statistically significant difference due to catalase genotypes (p=0,05). No difference in clinical characteristics, CIMT, plaque stability or plaque score was observed. Logistic regression model adjusted for age, gender, smoking, BMI, lipid parameters and duration of hypertension and diabetes showed significant association of T allele and lower risk for higher plaque score (OR=0,25; p=0,025). No association with CIMT>1mm and unstable plaques was observed. T allele of −262C/T is associated with lower risk for higher plaque score but it did not affect clinical parameters, CIMT and plaque stability. Whether this polymorphism can be used as a genetic marker for advanced carotid atherosclerosis in diabetic patients needs to be evaluated in the future.