Catalase C-262T polymorphism and risk of prostate cancer: evidence from meta-analysis

MTRR rs1532268 polymorphism and gastric cancer risk: evidence from a meta-analysis

OBJECTIVE

The methionine synthase reductase (MTRR) gene encodes the MTRR enzyme involved in the metabolic pathway of homocysteine. Several studies investigated the effect of the MTRR rs1532268 gene polymorphism on the risk of gastric cancer (GC), but the results have been inconsistent.

METHODS

We performed a comprehensive and systematic search of PubMed, Google Scholar, MEDLINE, Science Direct, Scopus, CNKI, and Web of Science. Five studies were included in this meta-analysis to determine whether MTRR rs1532268 polymorphism contributes to the risk of GC.

RESULTS

Pooled data indicated that the MTRR rs1532268 polymorphism significantly increased GC risk under the allele comparison model (odds ratio [OR] = 1.14, 95% confidence interval [CI] = 1.01-1.29) and dominant model (OR = 1.14, 95% CI = 1.00-1.30). In the analysis stratified by ethnicity, no relationship was found in Whites or Asians.

CONCLUSION

Our meta-analysis suggests a positive correlation between MTRR rs1532268 polymorphism and GC development.

An investigation of the relation between catalase C262T gene polymorphism and catalase enzyme activity in leukemia patients

INTRODUCTION

Catalase (CAT), an antioxidant enzyme, catalyzes conversion of hydrogen peroxide to water and molecular oxygen, protecting cells against oxidative stress. The aim of this study was to investigate the possible association between CAT C262T polymorphism in the promoter region of the CAT gene and leukemia risk and to determine the relationship between CAT genotypes and CAT enzyme activities.

MATERIAL AND METHODS

Genotypes of 102 cases and 112 healthy controls' genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism methods. Catalase activity was measured with the method of Aebi.

RESULTS

The frequencies of the T allele among the cases and controls were 28.4% and 25.9%, respectively (p = 0.75). The frequencies of CC, CT, and TT among cases were 57.8%, 27.4%, and 14.7%, respectively, while in controls, the frequencies of CC, CT, and TT were 54.4%, 39.3%, and 6.3%, respectively, which were not significantly different. Although CAT enzyme activity was lower in leukemia patients with TT genotypes than in controls, this did not reach statistical significance (p = 0.37).

CONCLUSIONS

This is the first report showing that CAT C262T polymorphism is not a genetic predisposing factor for the risk of leukemia in the Turkish population. However, additional research is needed to confirm these findings.

Impact of oxidative stress SNPs and dietary antioxidant quality score on prostate cancer

Purpose: To analyse the relation between antioxidant genotypes and Dietary Antioxidant Quality score (DAQs) effect on prostate cancer (PCa) risk and aggressiveness in a Spanish population.Methods: Men (N = 155 patients and 152 controls) with PSA values >4 ng/ml were enrolled in the project. DAQs were used considering the daily recommended intake for Spanish people (DRI). Genotyping of 5 SNPs rs662 (PON1), rs10432782 (SOD1), rs4880 (SOD2), rs17650792 (GPX1) and rs1001179 (CAT) were included for the analysis.Results: rs17650792 was statistically significant between case and controls subjects. When comparing D´Amico risk, we found that rs662 (CC), rs10432782 (G allele) and rs17650792 (GG) confer a protection. When testing SNP-antioxidant nutrients interactions, we found an intake of vitamin A and rs100179 (T carriers) and selenium and rs17650792 (G carriers) confers a protection of being in low risk classification.Conclusions: We reported by the first time a correlation between rs662 (PON1) and PCa aggressiveness.

Peroxisomal Hydrogen Peroxide Metabolism and Signaling in Health and Disease

Hydrogen peroxide (H₂O₂), a non-radical reactive oxygen species generated during many (patho)physiological conditions, is currently universally recognized as an important mediator of redox-regulated processes. Depending on its spatiotemporal accumulation profile, this molecule may act as a signaling messenger or cause oxidative damage. The focus of this review is to comprehensively evaluate the evidence that peroxisomes, organelles best known for their role in cellular lipid metabolism, also serve as hubs in the H₂O₂ signaling network. We first briefly introduce the basic concepts of how H₂O₂ can drive cellular signaling events. Next, we outline the peroxisomal enzyme systems involved in H₂O₂ metabolism in mammals and reflect on how this oxidant can permeate across the organellar membrane. In addition, we provide an up-to-date overview of molecular targets and biological processes that can be affected by changes in peroxisomal H₂O₂ metabolism. Where possible, emphasis is placed on the molecular mechanisms and factors involved. From the data presented, it is clear that there are still numerous gaps in our knowledge. Therefore, gaining more insight into how peroxisomes are integrated in the cellular H₂O₂ signaling network is of key importance to unravel the precise role of peroxisomal H₂O₂ production and scavenging in normal and pathological conditions.

Association of GPx1 P198L and CAT C-262T Genetic Variations With Polycystic Ovary Syndrome in Chinese Women

Background: Oxidative stress plays an important role in the pathogenesis of polycystic ovary syndrome (PCOS). Glutathione peroxidase 1 (GPx1) and catalase (CAT) are the major intracellular antioxidant enzymes that can detoxify hydrogen peroxide into water, preventing cellular injury from reactive oxygen species. The aim of the present study was to investigate the association of GPx1 P198L (Pro198Leu, C559T, rs1050450) and CAT C-262T (rs1001179) genetic polymorphisms with the risk of PCOS and evaluate the effects of the genotypes on clinical, hormonal, metabolic and oxidative stress parameters in Chinese women. Methods: This is a case-control study of 654 patients with PCOS and 535 controls. The GPx1 P198L, CAT C-262T, and superoxide dismutase 2 (SOD2) A16V genotypes were determined by polymerase chain reaction amplification and restriction analysis. Clinical, hormonal, metabolic and oxidative stress parameters were also analyzed. Results: The frequencies of the PL + LL genotype (14.1 vs. 8.4%) and L allele (7.3 vs. 4.4%) of GPx1 P198L polymorphism were significantly higher in patients with PCOS than in control subjects. Genotype (PL + LL) remained a significant predictor for PCOS in prognostic models including age, body mass index (BMI), insulin resistance index, total cholesterol, triglycerides, high-density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol as covariates (OR = 2.105, 95%CI: 1.330-3.331, P = 0.001). Patients carrying the L allele had relatively high average ovarian volume, waist circumference, and malondialdehyde levels (P < 0.07) compared with patients with the PP genotype. We also demonstrated that the subjects with both GPx1 L and SOD2 A alleles further increase the risk of PCOS compared with the individuals carrying the PP/VV genotype after adjusting for age and BMI (OR = 5.774, 95%CI: 2.243-14.863, P < 0.001). However, no significant differences were observed in the frequencies of the CAT C-262T genotypes and alleles between PCOS and control groups. Conclusions: The GPx1 P198L, but not CAT C-262T, genetic polymorphism is associated with the risk of PCOS in Chinese women.

Do histological variants in urothelial carcinoma of the bladder portend poor prognosis? A systematic review and meta-analysis

The clinical implications of histological variants in urothelial carcinoma of the bladder has been a subject of significant controversy with many unanswered questions that remain. To clarify whether histological variants presage poor prognosis for patients suffering from urothelial carcinoma of the bladder, we scoured through various electronic databases such as Medline, Web of Knowledge, and the Cochrane Library up to August 18, 2016. Experts were consulted, and references from relevant articles were scanned. We identified thirteen eligible studies which met the inclusion criteria, including 9,533 participants. The existing evidence indicates that histological variants in urothelial carcinoma of the bladder patients do not alter their prognosis.

Vulnerability of white matter tracts and cognition to the SOD2 polymorphism: A preliminary study of antioxidant defense genes in brain aging

Oxidative stress is a key mechanism of the aging process that can cause damage to brain white matter and cognitive functions. Polymorphisms in the superoxide dismutase 2 (SOD2) and catalase (CAT) genes have been associated with abnormalities in antioxidant enzyme activity in the aging brain, suggesting a risk for enhanced oxidative damage to white matter and cognition among older individuals with these genetic variants. The present study compared differences in white matter microstructure and cognition among 96 older adults with and without genetic risk factors of SOD2 (rs4880) and CAT (rs1001179). Results revealed higher radial diffusivity in the anterior thalamic radiation among SOD2 CC genotypes compared to CT/TT genotypes. Further, the CC genotype moderated the relationship between the hippocampal cingulum and processing speed, though this did not survive multiple test correction. The CAT polymorphism was not associated with brain outcomes in this cohort. These results suggest that the CC genotype of SOD2 is an important genetic marker of suboptimal brain aging in healthy individuals.

Association of the Common Catalase Gene Polymorphism rs1001179 With Glycated Hemoglobin and Plasma Lipids in Hyperlipidemic Patients

Catalase represents perhaps the most effective antioxidant defense in the body under conditions of increased oxidative stress, and rs1001179 (CAT-262C >T) is its most extensively studied gene polymorphism. Using an established PCR-RFLP method for genotyping, we examined the association of rs1001179 with glycated hemoglobin (HbA1c) and plasma lipids using univariate analyses with age, sex, body mass index (BMI), smoking, and alcohol abuse as covariates, in a group of dyslipidemic patients from northern Greece. Our results suggest that the TT genotype is a risk factor for increased HbA1c and plasma triglycerides, and that this association is modulated by the BMI and/or age of the patients.

Influence of A-21T and C-262T genetic polymorphisms at the promoter region of the catalase (CAT) on gene expression

OBJECTIVE

Catalase (CAT, OMIM: 115500) is one of the major antioxidant enzymes, which plays an important role in the clearance of reactive oxygen species. Three genetic polymorphisms of A-21T (rs7943316), C-262T (rs1001179), and C-844T (rs769214) in the promoter region of the CAT have been reported. It has been suggested that these polymorphisms may alter the recognition sites of transcriptional factors, therefore it might be concluded that these polymorphisms may alter the expression levels of the gene. The aim of the present study is to evaluate the associations between these genetic variations and the CAT mRNA levels in human peripheral blood cells.

METHODS

The present study consisted of 47 healthy students of Shiraz University (south-west Iran). Genotypes of the CAT polymorphisms were determined by PCR based method. The quantitative CAT mRNA expression levels were investigated using quantitative real-time PCR.

RESULTS

Analysis of variance revealed significant differences between the study genotypes (For A-21T polymorphism: F = 7.45; df = 2, 44; P = 0.002; For C-262T polymorphism: F = 15.17; df = 2, 44; P < 0.001). The studied polymorphisms showed linkage disequilibrium (D' = 1.0, r 2 = 0.1813, χ 2 = 17.03, P < 0.0001). The mRNA levels of CAT in the AC/TT, TC/TC, TC/TT, and TC/TC diplotypes significantly were higher than the mRNA levels in AC/AC diplotype. There was a significant difference between the study genotypes (F = 9.24; df = 5, 41; P < 0.001). The TC/TC and TT/TT diplotypes showed about 2 and 4 folds CAT mRNA levels compared with the AC/AC diplotype.

CONCLUSIONS

The present findings indicated that these polymorphisms were significantly associated with the gene expression.

Susceptibility to Ulcerative Colitis and Genetic Polymorphisms of A251G SOD1 and C-262T CAT

BACKGROUND

Reactive oxygen species can attack and damage almost every molecule found in living cells, including proteins, carbohydrates, lipids, and DNA. For this reason, their production is normally tightly controlled. Among the most important defenses against these radicals are the superoxide dismutase (SOD) enzymes and catalase (CAT). Increasing attention has been given to the role of reactive oxygen metabolites in the pathogenesis of ulcerative colitis (UC), which is defined as an idiopathic and chronic intestinal inflammation. Accordingly, we hypothesized a relation between genetic polymorphisms in the two antioxidant enzymes SOD1 A251G (rs2070424) and CAT C-262T (rs1001179) and the risk of UC.

METHODS

The present case-control study included 109 UC patients (46 males and 50 females) and 186 (67 males and 119 females) gender-matched healthy controls. Genotyping was done by the PCR-RFLP method.

RESULTS

After adjusting for age and gender, a significant association was observed between the AG+GG genotypes of SOD1 A251G polymorphism (vs. AA genotype) and risk of UC (OR=0.29, 95% CI: 0.10-0.86, P= 0.025) after adjusting for age and gender. Our statistical analysis revealed that the CAT C-262T polymorphism did not associate with the risk of UC before and/or after adjusting for age and gender.

CONCLUSIONS

Based on the present statistical analysis, the G allele of the SOD1 A251G polymorphism decreases the risk of UC, thus it might be assumed that the G allele has a protective role.

Expression of spermidine/spermine N(1) -acetyl transferase (SSAT) in human prostate tissues is related to prostate cancer progression and metastasis

INTRODUCTION

Prostate cancer (PCa) in many patients remains indolent for the rest of their lives, but in some patients, it progresses to lethal metastatic disease. Gleason score is the current clinical method for PCa prognosis. It cannot reliably identify aggressive PCa, when GS is ≤ 7. It is shown that oxidative stress plays a key role in PCa progression. We have shown that in cultured human PCa cells, an activation of spermidine/spermine N(1) -acetyl transferase (SSAT; EC 2.3.1.57) enzyme initiates a polyamine oxidation pathway and generates copious amounts of reactive oxygen species in polyamine-rich PCa cells.

METHOD

We used RNA in situ hybridization and immunohistochemistry methods to detect SSAT mRNA and protein expression in two tissue microarrays (TMA) created from patient's prostate tissues. We analyzed 423 patient's prostate tissues in the two TMAs.

RESULTS

Our data show that there is a significant increase in both SSAT mRNA and the enzyme protein in the PCa cells as compared to their benign counterpart. This increase is even more pronounced in metastatic PCa tissues as compared to the PCa localized in the prostate. In the prostatectomy tissues from early-stage patients, the SSAT protein level is also high in the tissues obtained from the patients who ultimately progress to advanced metastatic disease.

DISCUSSION

Based on these results combined with published data from our and other laboratories, we propose an activation of an autocrine feed-forward loop of PCa cell proliferation in the absence of androgen as a possible mechanism of castrate-resistant prostate cancer growth.