GSTM1 Genetic Polymorphisms Research Articles

Association GSTT1, GSTM1 and GSTP1 (Ile105Val) genetic polymorphisms in mothers with risk of congenital malformations in their children in Western Siberia: a case‐control study

Polymorphisms of glutathione S-transferase (GST) genes in mothers may be involved in teratogenesis in their offspring. This study aims to investigate the association of GST genes (T1, M1 and P1) with the risk of having children with congenital malformations (CMs) in residents of the West Siberian region of Russia. We studied 235 women with offspring's with CMs, and 273 women with one or more healthy children. Null genotypes of GSTM1 and GSTT1 were identified through multiplex real-time polymerase chain reaction, and GSTP1 gene (Ile105Val) polymorphism was determined through TaqMan-real-time polymerase chain reaction. The study showed that the maternal genotype GSTT1 «0/0» is associated with CMs in the offspring (odd ratio (OR) = 3.63, P = 5.18 × 10(-9) ). A significant association of the maternal genotype GSTT1 «0/0» with CMs of the cardiovascular system (OR = 5.03, P = 2.93 × 10(-7) ), urinary system (OR = 4.20, P = 3.51 × 10(-6) ) and central nervous system (OR = 4.40, P = 6.69 × 10(-5) ) was found in the child. No association of maternal GSTM1 (del) and GSTP1 (Ile105Val) genetic polymorphisms with CMs of the child was identified. Homozygous deletion of the GSTT1 gene in women of the West Siberian region is a risk factor for birth defects in the child.

GSTM1 and GSTT1 genetic polymorphisms and risk of anti-tuberculosis drug-induced hepatotoxicity: an updated meta-analysis

The results of studies investigating the associations between GSTM1 and GSTT1 polymorphisms and anti-tuberculosis drug-induced hepatotoxicity (ADIH) risk exhibit much controversy. Therefore, a meta-analysis was performed in order to examine the associations between GST variants and ADIH risk. A total of 451 relevant studies were identified through the digital medical databases Medline, Embase, and CBM published up to October 2012. Thirteen individual case-control studies were eventually recruited for GSTM1 null polymorphism (including 951 ADIH cases, 1,922 controls) and 12 studies for GSTT1 null polymorphism (847 cases, 1,811 controls). Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were appropriately calculated from fixed-effects or random-effects models. Subgroup analyses were stratified by ethnicity and different treatment combinations. The overall ORs of relevant studies that exhibited elevated ADIH risk was significantly associated with GSTM1 null genotypes (OR = 1.36, 95% CI 1.04-1.79), but for the GSTT1 polymorphism, no difference was found (OR = 0.98, 95% CI 0.82-1.18). In the subgroup analyses, the pooled results showed that GSTM1 null allele carriers had a significant association with ADIH risk in East Asians and the patients who used isoniazid (INH) + rifampicin (RMP) + pyrazinamide (PZA) + ethambutol (EMB), or + streptomycin (SM) (HRZES), but the opposite result was observed for patients using HR. Moreover, the GSTT1 null genotype evaluated the susceptibility to ADIH for tuberculosis using HRZ. This meta-analysis provides evidence that there may be an increased risk of ADIH in individuals with null genotypes of GSTM1 in the total population, especially East Asians and patients receiving HRZE or HRZES. However, polymorphisms of the GSTT1 null genotype seem to have no association with susceptibility to ADIH, except for patients receiving HRZ.

Association among Serum Organochlorine Pesticide Residues, Glutathione S-Transferase M1 Genetic Polymorphism and Female Breast Cancer

Background: The purpose of this study was to evaluate the association among serum organochlorine pesticide residues, glutathione S-transferase M1 genetic polymorphism and female breast cancer. Methods: A 1:1 matched case-control study of 140 newly diagnosed breast cancer patients and 140 non-cancer female patients who consulted the five largest hospitals in the Tangshan city from September 2006 to October 2007. Results: The result showed higher risk of breast cancer among subjects with higher levels of serum DDT and HCH residue, the OR was 3.18 (95%CI, 1.11 - 9.07) and 5.02 (95%CI, 1.64 - 16.56).The value of ORe associated with single environmental factor DDT high residues, and ORg associated with single GSTM1 deletion genotype were respectively 3.86 (1.20 - 12.47) and 1.34 (0.36 - 5.08). The OReg associated with combined action of two factors was 5.59 (1.63 - 18.90), and the value of interaction parameters (γ) equaled 1.24. The value of ORe associated with single environmental factor HCH higher residue and ORg associated with single GSTM1 deletion genotype were respectively 2.73 (0.84 - 8.87) and 1.48 (0.49 - 4.60). The value of OReg associated with combined action of two factors was 3.87 (1.18 - 12.68), and γ equaled 1.38. Conclusion: The results indicated that breast cancer occurrence was the combined result of environmental and genetic factors. The concurrent action of GSTM1 deletion genotype and DDT/HCH enhanced the risk of breast cancer.

Genetic Polymorphisms of GSTM1 and GSTT1 Genes in Delhi and Comparison with other Indian and Global Populations

The glutathione S-transferases (GSTs) are involved in the metabolism of many xenobiotics, including an array of environmental carcinogens, pollutants, and drugs. Genetic polymorphisms in these genes may lead to inter- individual variation in susceptibility to various diseases. In the present study, GSTM1 and GSTT1 polymorphisms were analysed using a multiplex polymerase chain reaction in 500 normal individuals from Delhi. The frequency of individuals with GSTM1 and GSTT1 null genotypes were 168 (33.6%) and 62 (12.4%) respectively, and 54 (10.8%) were having homozygous null genotype for both the genes GSTM1 and GSTT1 simultaneously. The studied population was compared with reported frequencies from other neighbouring state populations, as well as with those from other ethnic groups; Europeans, Blacks, and Asians. The prevalence of homozygous null GSTM1 genotype is significantly higher in Caucasians and Asians as compared to Indian population. The frequency of GSTT1 homozygous null genotypes is also significantly higher in blacks and Asians. We believe that due to large number of individuals in this study, our results are reliable estimates of the frequencies of the GSTM1, GSTT1 in Delhi. It would provide a basic database for future clinical and genetic studies pertaining to susceptibility and inconsistency in the response and/or toxicity to drugs known to be the substrates for GSTs.

Associations of GSTM1 and GSTT1 polymorphisms with pancreatic cancer risk

Glutathione S-transferases (GSTs), including glutathione S-transferase M1 (GSTM1) and glutathione S-transferase T1 (GSTT1), are multifunctional enzymes which play vital roles in the detoxification of a variety of carcinogens. The genetic polymorphisms of GSTM1 and GSTT1 have been implicated in pancreatic cancer risk, but the results of published studies remain conflicting. Thus, a meta-analysis was conducted to estimate the effect of GSTM1 and GSTT1 polymorphisms on the risk of developing pancreatic cancer. A comprehensive search was performed in the PubMed, Embase, Web of Science, and Wanfang databases to identify the available studies on the associations of GSTM1 and GSTT1 polymorphisms with pancreatic cancer risk. The pooled odds ratio (OR) with its corresponding 95 % confidence interval (95 % CI) was used to estimate the associations. Stratified analyses by ethnicity and sensitivity analyses were performed to further identify the relationships. Overall, the null genotype of GSTT1 was associated with an increased risk of pancreatic cancer (OR = 1.61, 95 % CI 1.06-2.44, P OR = 0.025), but similar association was not found between the null genotype of GSTM1 and pancreatic cancer risk. Besides, a significant association of GSTT1 polymorphism with pancreatic cancer risk was identified in Asians (OR = 2.58, 95 % CI 1.67-3.98, P OR < 0.001), but not in Caucasians (OR = 1.16, 95 % CI 0.94-1.43, P OR = 0.170). Sensitivity analyses by sequential omission of individual study confirmed the stability of our results. Meta-analysis of available data thus far shows that the null genotype of GSTT1 is a risk factor for pancreatic cancer, particularly in the Asian population. The currently available data are not sufficient enough to identify the association between the GSTM1 polymorphism and pancreatic cancer risk.

Genetic Polymorphisms of GSTM1, GSTT1, and GSTP1 with Prostate Cancer Risk: A Meta-Analysis of 57 Studies

Background and ObjectivesThe GSTM1, GSTT1 and GSTP1 polymorphisms might be involved in inactivation of procarcinogens that contribute to the genesis and progression of cancers. However, studies investigating the association between GSTM1, GSTT1 or GSTP1 polymorphisms and prostate cancer (PCa) risk report conflicting results, therefore, we conducted a meta-analysis to re-examine the controversy.MethodsPublished literature from PubMed, Embase, Google Scholar and China National Knowledge Infrastructure (CNKI) were searched (updated to June 2, 2012). According to our inclusion criteria, studies that observed the association between GSTM1, GSTT1 or GSTP1 polymorphisms and PCa risk were included. The principal outcome measure was the odds ratio (OR) with 95% confidence interval (CI) for the risk of PCa associated with GSTM1, GSTT1 and GSTP1 polymorphisms.ResultsFifty-seven studies involving 11313 cases and 12934 controls were recruited. The overall OR, which was 1.2854 (95% CI = 1.1405–1.4487), revealed a significant risk of PCa and GSTM1 null genotype, and the similar results were observed when stratified by ethnicity and control source. Further, the more important is that the present study first reported the high risks of PCa for people who with dual null genotype of GSTM1 and GSTT1 (OR = 1.4353, 95% CI = 1.0345–1.9913), or who with GSTT1 null genotype and GSTP1 A131G polymorphism (OR = 1.7335, 95% CI = 1.1067–2.7152). But no association was determined between GSTT1 null genotype (OR = 1.102, 95% CI = 0.9596–1.2655) or GSTP1 A131G polymorphism (OR = 1.0845, 95% CI = 0.96–1.2251) and the PCa risk.ConclusionsOur meta-analysis suggested that the people with GSTM1 null genotype, with dual null genotype of GSTM1 and GSTT1, or with GSTT1 null genotype and GSTP1 A131G polymorphism are associated with high risks of PCa, but no association was found between GSTT1 null genotype or GSTP1 A131G polymorphism and the risk of PCa. Further rigorous analytical studies are highly expected to confirm our conclusions and assess gene-environment interactions with PCa risk.

GSTM1 polymorphism modifies the effect of smoking on calcaneal quantitative ultrasound in young men

Evidence suggests that smoking adversely affects bones. Glutathione S-transferases (GSTs) are important in the detoxification of tobacco smoke compounds. This study investigated the influence of GSTM1 and GSTT1 genetic polymorphisms on the effects on bone induced by tobacco smoking in young men. In total, 231 Chinese men aged 20-39 years were assessed by a cross-sectional study. Calcaneal quantitative ultrasound (QUS) was measured. Smoking information was obtained using a questionnaire. Genotypes were determined for null alleles of GSTM1 and GSTT1. Smoking was inversely associated with speed of sound (SOS) and bone quality index (BQI) among subjects with GSTM1 null genotype (β = -0.28, 95% CI, -34.01 to -8.65 and β = -0.30, 95% CI, -16.41 to -4.49, respectively), but not among those with the allele present (β = -0.02, 95% CI, -15.01 to 12.59 and β = -0.09, 95% CI, -8.75 to 3.02, respectively). P for interaction = 0.04 for SOS and 0.08 for BQI. No interaction was found between the GSTT1 polymorphism and smoking. The results showed that GSTM1 deficiency may increase the adverse effect of smoking on calcaneal QUS in young men, suggesting an interaction between metabolic genes and tobacco smoke in bone detoxification.

Reporting Genetic Association Studies: The Roadblocks and Guiding Rules for Robust Results

Congratulations to Dr. Birbian and colleagues for their article ‘‘GSTT1 and GSTM1 Gene Polymorphisms as Major Risk Factors for Asthma in a North Indian Population’’ [1]. Theirs was the first published study on GSTT1 and GSTM1 genetic polymorphisms in a north Indian population using a case–control design. The study was carried out on a good sample size and a number of conclusions were drawn. However, we felt that the authors should have followed the international guidelines for reporting genetic association studies (STREGA) [2] to add lasting value to their findings. Case–control association studies are valiant way to detect associations in a resource-limited setting, but in reporting the results of such studies there are several roadblocks that must be cleared and addressed before arriving at robust and useful conclusions. The ultimate goal of all such studies is to arrive at very futuristic individualized medicine and an immunotherapeutic approach to disease. Transparency and accuracy of the reported results of medical research must be ensured to enhance the value of such studies. The formation of the STrengthening the REporting of Genetic Association (STREGA) studies guidelines was a significant step in that direction; they were published in many journals simultaneously [2]. There are a number of considerations but three of the most important that have been shown time and again to be of great value are as follows:

Association of glutathione S-transferase M1 polymorphisms and lung cancer risk in a Chinese population

BackgroundGenetic polymorphisms of glutathione S-transferase M1 (GSTM1) are thought to have significant effects on the metabolism of environmental carcinogens and thus on lung cancer risk, but the reported results are not always consistent. The aim of this study is to investigate the relationship between GSTM1 genetic polymorphism and lung cancer risk in a Chinese population. MethodsA population-based control study was conducted in 360 lung cancer patients and 360 cancer-free controls. The genotype of the GSTM1 gene was determined by using a polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) assay. ResultsWe observed a stronger association between GSTM1 null genotype and lung cancer [odds ratio (OR)=1.59, 95% confidence interval (CI)=1.17, 2.17; P=0.003]. This association was also found in squamous cell carcinoma (OR=1.73, 95% CI=1.16, 2.59; P=0.008). In the analysis combining GSTM1 polymorphism and smoking, smokers with the null genotype who had smoked for ≥30 pack-years had higher risk (OR=10.06, 95% CI=5.16, 19.61; P<0.001) compared with non-smokers with the wild-type genotype. ConclusionsThis study suggested that GSTM1 polymorphism plays a role in the development of lung cancer and modifies the risk for smoking-related lung cancer in a Chinese population.

The link between genetic polymorphism of glutathione-S-transferases, GSTM1, and GSTT1 and diffuse large B-cell lymphoma in Egypt

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma. A number of studies have examined the role of genetic polymorphisms in the risk of DLBCL, and several variants have been identified as potential susceptibility genes, of those glutathione-S-transferases T1 and M1 (GSTT1 and GSTM1). The aim of the current study was to investigate the influence of inherited genetic polymorphisms of GSTM1 and GSTT1 genes on the susceptibility to DLBCL in Egypt. Genotyping of the candidate genes was performed for 71 Egyptian DLBCL patients and 100 age- and gender-matched healthy controls by multiplex polymerase chain reaction technique. The frequencies of GSTT1 null, GSTM1 null, and dual null genotypes among DLBCL patients were 47.9, 52.1, and 23.9 % respectively. GSTT1 null genotype conferred almost fourfold increased risk of DLBCL (OR = 3.9, 95 % CI = 1.97-7.75), and the risk increased when confined to male patients (OR = 4.4, 95 % CI = 1.57-12.63), while GSTM1 null genotype was not associated with DLBCL risk. Further studies on the functional consequences of GSTT1 and GSTM1 genetic polymorphisms would pave the way to declare their role in the pathogenesis of DLBCL or as possible predictors for response to therapy.

CYP2E1,GSTM1andGSTT1genetic polymorphisms and susceptibility to antituberculosis drug-induced hepatotoxicity: a nested case-control study

The pathogenic mechanism of antituberculosis drug-induced hepatotoxicity (ATDH) is thought to involve drug-metabolizing enzymes including N-acetyl transferase2 (NAT2), cytochrome P4502E1 (CYP2E1) and glutathione S-transferase (GST) M1, T1. The associations between genetic polymorphisms of those genes and ATDH have been reported but with inconsistent results. Moreover, most studies were hospital-based retrospective studies and not prospective. We aimed to investigate possible associations of CYP2E1, GSTM1 and GSTT1 genetic polymorphisms with ATDH using a more robust case-control study nested in a population-based prospective antituberculosis treatment cohort. A total of 4304 patients with smear-positive tuberculosis (TB) who received standard short-course chemotherapy were monitored for 6-9 months. Incidence density sampling method was adopted to select controls and 4 : 1 matched with each ATDH cases by age (± 5 years), sex, treatment history, disease severity and drug dosage. The CYP2E1, GSTM1 and GSTT1 polymorphisms were genotyped using PCR-RFLP and multiplex PCR methods. Conditional logistic regression model was used to calculate odds ratio (OR) and 95% confidence interval (CI), as well as corresponding P-values. A total of 89 ATDH cases and 356 controls were included in this study. There was no statistically significant association between CYP2E1 RsaI c1/c1 genotype or DraI C/C genotype and ATDH (OR = 0·99, 95% CI:0·62-1·59; OR = 1·13, 95% CI: 0·40-3·20, respectively) compared with CYP2E1 RsaI c1/c2 or c2/c2 genotypes or DraI D/D genotype, or between GSTM1/GSTT1 null genotypes and ATDH (OR = 1·22, 95% CI: 0·76-1·96; OR = 0·96, 95% CI: 0·60-1·52, respectively) compared with non-null genotypes. This is the first study of the involvement of CYP2E1, GSTM1 and GSTT1 genetic polymorphisms in ATDH using a nested case-control population-based prospective cohort design. We could not confirm positive associations of genetic polymorphisms of CYP2E1 RsaI, CYP2E1 DraI, GSTM1 null and GSTT1 null with ATDH reported by various groups, in our Chinese TB population.

Effects of CYP1A1 and GSTM1 gene polymorphisms and BPDE-DNA adducts on lung cancer

To investigate the effect of CYP1A1 and GSTM1 genetic polymorphisms and BPDE-DNA adducts on lung tumorigenesis. The case control study has included 200 cases of lung cancer and 200 controls. DNA was extracted from blood samples of all subjects. The genotype of both CYP1A1 and GSTM1 were detected with PCR-based restriction fragment length polymorphisms (PCR-RELP). BPDE-DNA adducts were detected with competitive ELISA. CYP1A1 mutant genotype and GSTM1 null genotype with smoke has increased the risk of lung cancer, with OR being 2.406(1.321-4.382), 2.755(1.470-5.163), respectively. The level of BPDE-DNA adducts in patients was greater than control, and the adduct level in ever smokers was higher than never smokers, the difference was statistically significant (P= 0.0252). GSTM1 null genotype individuals with BPDE-DNA level higher than 5 adducts/10(8) nucleotide have increased risk of lung cancer (OR= 1.988, 95%CI: 1.011-3.912). Compared with never smokers with CYP1A1 wild genotype, smokers with CYP1A1 mutation genotype had an increased risk of forming a higher level of DNA adducts (P= 0.0459). Smokers with GSTM1 null genotype formed more DNA adducts compared with never smokers with GSTM1 functional genotype (OR = 2.432, 95% CI: 1.072-4.517). GSTM1 null genotype with higher level DNA adducts may increase the risk of lung cancer. DNA adducts form easier in smokers with CYP1A1 mutation genotype and GSTM1 null genotype, which in turn may influence lung tumorigenesis.

Human GSTs Polymorphisms in the Hakka Population of South China and Their Associations with Family History of Several Chronic Diseases

Objective To investigate the associations of genetic polymorphisms in GSTs genes of the Hakka population of south China with family histories of certain chronic diseases. Methods Five hundred and thirty-nine healthy Hakka natives of Meizhou city of Guangdong province in south China were involved. The genotypes of GSTM1, GSTT1, GSTP1, GSTM3, and GSTA1 were determined using PCR and restriction fragment length polymorphism analysis. The observed polymorphisms were analyzed by Chi-square and Hardy-Weinberg equilibrium tests. Logistic regression analysis was used to determine the associations of the distributions of GST genotypes with family history of certain chronic diseases. Results The distributions of polymorphisms in GSTP1, GSTM3, and GSTA1 conformed to the Hardy-Weinberg equilibrium. Compared to the Cantonese, the Hakka had a lower distribution of the GSTM3 deletion genotype (3.15% vs. 11.9%). A weak association was observed between the GSTM1 genetic polymorphism and family history of hypertension. Alcohol drinkers had a higher frequency of the null- GSTM1 genotype, while smokers had a higher frequency of a variant GSTP1 genotype. Conclusion The results suggest that the Hakka is a special and distinctive Han Chinese ethnic group with different GSTs genetic polymorphisms. Smoking and drinking might be related to the distribution of GST genotypes.

Influence of CYP2C9, GSTM1, GSTT1 and NAT2 genetic polymorphisms on DNA damage in workers occupationally exposed to organophosphate pesticides

Previous studies have revealed that organophosphate pesticides (OPs) are primarily metabolized by xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticides-exposed workers. Present study was designed to determine the influence of CYP2C9, GSTM1, GSTT1 and NAT2 genetic polymorphisms on DNA damage in workers occupationally exposed to OPs. We examined 268 subjects including 134 workers occupationally exposed to OPs and an equal number of normal healthy controls. The DNA damage was evaluated using alkaline comet assay and genotyping was done using individual polymerase chain reaction (PCR) or polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). Acetylcholinesterase and paraoxonase activity were found to be significantly lowered in workers as compared to control subjects which were analyzed as biomarkers of toxicity due to OPs exposure ( p < 0.001). Workers showed significantly higher DNA tail moment (TM) compared to control subjects (14.32 ± 2.17 vs. 6.24 ± 1.37 tail % DNA, p < 0.001). GSTM1 null genotype was found to influence DNA TM in workers ( p < 0.05). DNA TM was also found to be increased with concomitant presence of NAT2 slow acetylation and CYP2C9*3/ *3 or GSTM1 null genotypes ( p < 0.05). DNA TM was found increased in NAT2 slow acetylators with mild and heavy smoking habits in control subjects and workers, respectively ( p < 0.05). The results of this study suggest that GSTM1 null genotypes, and an association of NAT2 slow acetylation genotypes with CYP2C9*3/ *3 or GSTM1 null genotypes may modulate DNA damage in workers occupationally exposed to OPs.

Glutathione S-transferase gene polymorphisms are not major risks for susceptibility to posttransplantation diabetes mellitus in Taiwan renal transplant recipients

Glutathione S-transferase (GST) M1 null genotype has been reported playing a significant role in the diabetes mellitus (DM) susceptibility in Turkish population. We investigated whether the GSTM1, GSTA1, and GSTP1 gene polymorphisms are associated with posttransplantation diabetes mellitus (PTDM) in Taiwan. There were 283 renal transplant recipients (RTRs) enrolled. Polymerase chain reaction-restriction fragment length polymorphism was used for the measurement of GSTA1, M1, and P1 genetic polymorphisms. PTDM was diagnosed according to the American Diabetes Association guidelines. Eight-five patients (30%) were diagnosed with PTDM. The averaged posttransplant follow-up period was 77.9 ± 27.2 months. Duration from transplantat to diagnosis of PTDM ranged from 0.2 to 103.1 months (19.2 ± 26.3 months). There were significantly differences between non-DM and PTDM groups in age (50.6 ± 11.0 vs. 54.6 ± 9.36 years, P = 0.005), BMI (22.4 ± 3.6 vs. 24.3 ± 3.8, P<0.001). The distributions of GSTA1, GSTP1, and GSTM1 genotypes alleles were not significantly different between PTDM and non-DM group. Patients carrying the different GSTA1, GSTP1, and GSTM1 genetic and allelic polymorphisms had no differences for the development of PTDM. These overall results suggested a lack of strong association with GSTA1, GSTP1, and GSTM1 genetic polymorphisms to the susceptibility of PTDM in Taiwanese RTRs.

Genetic polymorphisms in glutathione S-transferase (GST) superfamily and risk of arsenic-induced urothelial carcinoma in residents of southwestern Taiwan

BackgroundArsenic exposure is an important public health issue worldwide. Dose-response relationship between arsenic exposure and risk of urothelial carcinoma (UC) is consistently observed. Inorganic arsenic is methylated to form the metabolites monomethylarsonic acid and dimethylarsinic acid while ingested. Variations in capacity of xenobiotic detoxification and arsenic methylation might explain individual variation in susceptibility to arsenic-induced cancers.MethodsTo estimate individual susceptibility to arsenic-induced UC, 764 DNA specimens from our long-term follow-up cohort in Southwestern Taiwan were used and the genetic polymorphisms in GSTM1, GSTT1, GSTP1 and arsenic methylation enzymes including GSTO1 and GSTO2 were genotyped.ResultsThe GSTT1 null was marginally associated with increased urothelial carcinoma (UC) risk (HR, 1.91, 95% CI, 1.00-3.65), while the association was not observed for other GSTs. Among the subjects with cumulative arsenic exposure (CAE) ≥ 20 mg/L*year, the GSTT1 null genotype conferred a significantly increased cancer risk (RR, 3.25, 95% CI, 1.20-8.80). The gene-environment interaction between the GSTT1 and high arsenic exposure with respect to cancer risk was statistically significant (multiplicative model, p = 0.0151) and etiologic fraction was as high as 0.86 (95% CI, 0.51-1.22). The genetic effects of GSTO1/GSTO2 were largely confined to high arsenic level (CAE ≥ 20). Diplotype analysis showed that among subjects exposed to high levels of arsenic, the AGG/AGG variant of GSTO1 Ala140Asp, GSTO2 5'UTR (-183)A/G, and GSTO2 Asn142Asp was associated with an increased cancer risk (HRs, 4.91, 95% CI, 1.02-23.74) when compared to the all-wildtype reference, respectively.ConclusionsThe GSTs do not play a critical role in arsenic-induced urothelial carcinogenesis. The genetic effects of GSTT1 and GSTO1 on arsenic-induced urothelial carcinogenesis are largely confined to very high exposure level.

Genetic polymorphisms of GSTM1, GSTT1 and GSTP1 and susceptibility to DNA damage in workers occupationally exposed to organophosphate pesticides

GSTM1, T1 and P1 are important enzymes of glutathione S-transferases (GSTs), involved in the metabolism of many endogenous and exogenous compounds. Individual genetic variation in these metabolizing enzymes may influence the metabolism of their substrates. The present study was designed to determine the genotoxic effects using DNA damage and its association with GSTM1, GSTT1, and GSTP1 (Ile105Val) genetic polymorphisms in workers occupationally exposed to organophosphate pesticides (OPs). We examined 230 subjects including 115 workers occupationally exposed to OPs and an equal number of normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using individual PCR or PCR–RFLP. Significantly higher DNA tail moment (TM) was observed in workers as compared to control subjects (14.41±2.25 vs. 6.36±1.41 tail % DNA, p<0.001). The results revealed significantly higher DNA TM in workers with GSTM1 null genotype than those with GSTM1 positive (15.18 vs. 14.15 tail % DNA, p=0.03). A significantly higher DNA TM was also observed in workers with homozygous Ile–Ile GSTP1 genotype than heterozygous (Ile–Val) and mutant (Val–Val) GSTP1 genotype (p=0.02). In conclusion, the results show that null deletion of GSTM1 and homozygote wild GSTP1 genotype could be related to inter-individual differences in DNA damage arises from the gene–environment interactions in workers occupationally exposed to OPs.

Correlation between generic polymorphisms of glutathione S-transferases and ulcerative colitis in Hubei Han population

Objective To investigate the correlation between genetic polymorphisms of glutathione S-transferases (GSTs) and ulcerative colitis (UC) in Hubei Han population. Methods Genetic polymorphisms of GSTM1 and GSTT1 of 270 patients with UC (UC group) who were admitted to the Zhongnan Hospital, People's Hospital of Wuhan University, Tongji Hospital and Union Hospital of Huazhong University of Science and Technology from August 2002 to December 2009 and 623 healthy people ( control group) were detected by restriction fragment length polymorphism-polymerase chain reaction. All UC patients were allocated to distal UC group (n= 229) and extensive UC group (n =41 ) according to the location of the lesions; and all UC patients were also allocated to mild-moderate group (n = 237) and severe group (n = 33 ). The genetic polymorphisms of GSTP1 of these patients and healthy people were detected by polymerase chain reaction. The genotypes of GSTM1, GSTT1 and GSTP1 were also detected. GSTM1 and GSTT1 containing small DNA segments ( 157 bp and 480 bp) were defined as GSTM1 (+) and GSTT1 (+), otherwise, GSTM(-) and GSTT1 (-), respectively. All data were analyzed by chisquare test. Results The frequencies of GSTM1(-), GSTT1(-) and GSTP1 (Val/Val) were 70.7% (191/270),64.8% (175/270) and 48.9% (132/270) in the UC group, and 41.7% (260/623), 47.2% ( 294/623 ) and 34.3% (214/623) in the control group, with a significant difference between the two groups (x2 = 63. 404,22. 320, 25. 384, P ＜0.05 ). The frequencies of GSTT1 (-) and GSTP1 (Val/Val) were 71.6% (164/229) and 57.6% (132/229) in the distal UC group, which were significantly higher than 31.7% (13/41) and 29.3%( 12/41 ) in the extensive UC group ( x2 = 24.528, 9.609, P ＜ 0.05 ). The frequencies of GSTM1 (-) were 65.1%(149/229) in the distal UC group and 56.1% (23/41) in the extensive UC group, with no significant difference between the two groups ( x2 = 1. 210, P ＞ 0.05 ). The frequencies of GSTT1 (-) and GSTP1 ( Val/Val ) were 71.6%(164/229), 31.7% ( 13/41 ) in the distal UC group and 57.6% ( 132/229), 29.3% ( 12/41 ) in the extensive UC group, with a significant difference between the two groups ( x2 = 24. 528, 9. 609, P ＜ 0. 05 ). There was no significant difference in the frequencies of GSTM1 (-), GSTT1 (-), GSTP1 (Val/Val) in the mild-moderate group and the severe group( x2 = 0. 623, 1. 884, 3. 403, P ＞ 0. 05 ). Conclusions Variant genotypes of GSTs are significantly correlated with UC in Hubei Han population. The severity of UC may not be correlated with variant genotypes of GSTs. Key words: Ulcerative colitis; Glutathione S-transferase; Genetic polymorphism

Correlation of EPHX1, GSTP1, GSTM1, and GSTT1 genetic polymorphisms with antioxidative stress markers in chronic obstructive pulmonary disease

ABSTRACTThis study was undertaken to ascertain if a relationship existed between oxidative status and polymorphisms of microsomal epoxide hydrolase X1 (EPHX1), glutathione S-transferase P1 (GSTP1), GSTM1, and GSTT1 in chronic obstructive pulmonary disease (COPD). Erythrocyte glutathione peroxidase (GSH-px), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), and plasma GST activities and total antioxidant status (TAS) as antioxidative stress markers were determined and compared either with individual and combined genotypes of EPHX1 exon 3, GSTP1 exon 5, GSTM1, and GSTT1 polymorphisms in COPD patients and healthy controls from the central area of Tunisia. Statistical data processing revealed significantly lower GSH-px, GR, SOD, CAT, GST, and TAS values in COPD patients in comparison to the control group (P < .001). As for genotypes, there was a no significant association in each of the 6 parameters and individual genotypes (P > .05). A significant correlation between the studied parameters and combined null GSTM1/null GSTT1 (GSH-px: P < .001, GR: P = .026, CAT: P = .018, GST: P = .022, TAS: P = .046), His113His EPHX1/null GSTM1 (GSH-px: P = .001, GST: P = .0012, TAS: P = .013), His113His EPHX1/Val105Val GSTP1 (GSH-px: P = .048, CAT: P = .026, GST: P = .031), and null GSTM1/Val105Val GSTP1 (GSH-px: P = .011, GR: P = .0028, GST: P = .0054, TAS: P = .032) was found in patients. In conclusion, combined genetic polymorphisms of GSTM1, GSTT1, GSTP1, and EPHX1 may have favorable effects on redox balance in COPD patients.

Combined Analysis of EPHX1, GSTP1, GSTM1 and GSTT1 Gene Polymorphisms in Relation to Chronic Obstructive Pulmonary Disease Risk and Lung Function Impairment

Smoking is considered as the major causal factor of chronic obstructive pulmonary disease (COPD). Nevertheless, a minority of chronic heavy cigarette smokers develops COPD. This suggests important contribution of other factors such as genetic predisposing. Our objective was to investigate combined role of EPHX1, GSTP1, M1 and T1 gene polymorphisms in COPD risk, its phenotypes and lung function impairment. Prevalence of EPHX1, GSTP1, M1 and T1 gene polymorphisms were assessed in 234 COPD patients and 182 healthy controls from Tunisia. Genotypes of EPHX1 (Tyr113His; His139Arg) and GSTP1 (Ile105Val; Ala114Val) polymorphisms were performed by PCR-RFLP, while the deletion in GSTM1 and GSTT1 genes was determined using multiplex PCR. Analysis of combinations showed a significant association of 113His/His EPHX1/null-GSTM1 (OR = 4.07) and null-GSTM1/105Val/Val GSTP1 (OR = 3.56) genotypes with increased risk of COPD (respectively P=0.0094 and P=0.0153). The null-GSTM1/ null-GSTT1, 105Val/Val GSTP1/null GSTT1, 113His/His EPHX1/null-GSTM1 and null-GSTM1/105Val/Val GSTP1 genotypes were related to emphysema (respectively P = 0.01; P = 0.009; P = 0.008 and P = 0.001). Combination of 113His/His EPHX1/null-GSTM1 genotypes showed a significant association with the decrease of ΔFEV1 in patients (P = 0.028).In conclusion, our results suggest combined EPHX1, GSTP1, GSTM1 and GSTT1 genetic polymorphisms may play a significant role in the development of COPD, emphysema and decline of the lung function.