Relationship between GSTs gene polymorphism and susceptibility to end stage renal disease among North Indians

BACKGROUND AND OBJECTIVE: Glutathione-S-transferase (GST) is the superfamily of genes that provides protection to the cells against reactive oxygen species and plays a vital role in phase II of biotransformation of many substances. Overexpression of GST (EC 2.5.1.18) has been documented in the erythrocytes of patients with chronic renal failure, which may be of clinical relevance. Keeping this background in mind, we have investigated the relationship between human GST gene polymorphism in end stage renal disease (ESRD) patients. DESIGN AND METHODS: We have assessed 184 patients with ESRD and 569 age-and sex-matched controls from North India. The GSTT1 and GSTM1 null genotypes were identified by polymerase chain reaction (PCR). GSTP1-313 A/G mutation was determined by PCR followed by restriction enzyme digestion. RESULTS: The gene frequency of GSTM1, GSTT1, and GSTP1 polymorphism were evaluated. We observed that GSTM1 null genotype was present in 46.74% of the ESRD patients while GSTT1 null genotype was present in 58.7% of the ESRD subjects. The genotypic distribution of GSTP1 was Ile(105)/Ile(105) in 47.3%, Ile(105)/Val(105) in 30.97% and Val(105)/Val(105) in 21.74% of ESRD patients. There was a significant association of null alleles of the GSTM1 (p = 0.0386; OR = 1.445, 95% CI = 1.033-2.021) and GSTT1 (p < or = 0.0001; OR = 4.568, 95% CI = 3.215-6.492) and in the -313 G alleles (Val) of the GSTP1 gene (p = 0.0032; OR = 1.956, 95% CI = 1.265-3.024) with end stage renal disease. The combined analysis of the three genotypes showed a further increased risk to ESRD (p < or = 0.0001; OR = 9.01, 95% CI = 5.55-14.626). Interpretations and CONCLUSIONS: The null / low polymorphism of the detoxifying enzymes GSTT1, GSTM1, and GSTP1 are associated with the risk of developing ESRD in North Indian patients.     

Relationship between GSTM1/GSTT1 Null Genotypes and Renal Cell Carcinoma Risk: A Meta-Analysis

The results from the published studies on the relationship between GSTM1/GSTT1 null genotypes and renal cell carcinoma (RCC) risk are still conflicting. This meta-analysis was performed to evaluate the relationship between GSTM1/GSTT1 null genotypes and RCC susceptibility. Association studies were identified from the databases of PubMed, Embase, Cochrane Library, and CBM-disc (China Biological Medicine Database) on 1 February 2012, and eligible investigations from 1950 to 2012 were synthesized using meta-analysis method. Results were expressed as odds ratios (ORs) for dichotomous data, and 95% confidence intervals (CIs) were also calculated. Six studies were identified for the analysis of association between polymorphic deletion of GSTM1/GSTT1 and RCC risk. There was no association between GSTM1/GSTT1 null genotype and RCC susceptibility (GSTM1: N = 6, p-heterogeneity = 0.07, OR = 1.07, 95% CI: 0.85–1.35, p = 0.57; GSTT1: N = 6, p-heterogeneity < 0.00001, OR = 0.98, 95% CI: 0.58–1.65, p = 0.94). Interestingly, null genotype of GSTT1 was associated with RCC risk in Caucasians and Asians (Caucasians: N = 4, p-heterogeneity = 0.38, OR = 0.76, 95% CI: 0.61–0.95, p = 0.01; Asians: N = 1, OR = 2.39, 95% CI: 1.63–3.51, p < 0.00001). For the GSTM1–GSTT1 interaction analysis, the dual null genotype of GSTM1/GSTT1 was not significantly associated with RCC susceptibility (N = 4, p-heterogeneity = 0.006, OR = 1.17, 95% CI: 0.98–1.39, p = 0.09). However, the dual null genotype of GSTM1–GSTT1 was associated with RCC risk in Asians (N = 1, OR = 2.06, 95% CI: 1.36–3.13, p = 0.007). In conclusion, our study results suggest that GSTT1 null genotype is associated with the RCC susceptibility in Caucasians and Asians, and the dual null genotype of GSTM1–GSTT1 is associated with RCC risk in Asians. However, more genetic epidemiological investigations are required to further explore this relationship.     

Association of genetic polymorphism of glutathione S-transferase (GSTM1, GSTT1, GSTP1) with bladder cancer susceptibility

The glutathione-S-transferases (GSTs) comprise a class of enzymes that detoxify carcinogenic compounds by conjugating glutathione to facilitate their removal. Polymorphisms in GSTM1, GSTT1, and GSTP1 genes have been related to risk for bladder cancer. Studies focusing on GSTs gene variants relationship with the risk of bladder cancer have produced conflicting and inconsistent results. We examine the association between genetic polymorphism of glutathione S-transferase P1, GSTM1, GSTT1 genes and development of bladder transitional cell carcinoma (TCC). The study population consisted of 166 histologically confirmed male bladder TCC cases and 332 healthy male controls. Genotyping was done using the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method and also investigated combined gene interactions. The GSTP1 Val/Val genotype was significantly associated with bladder cancer (OR = 4.32, 95% CI: 2.64–6.34), whereas the association observed for GSTM1 null (OR = 1.32, 95% CI: 0.82–2.62; P = 0.67) and GSTT1 null genotype (OR = 1.18, 95% CI: 0.79–1.67; P = 0.74) did not reach statistical significance. There was a significant multiple interaction between GSTM1, GSTT1, and GSTP1 genotypes in risk of bladder cancer (P for interaction = 0.02). The risk associated with the concurrent presence of GSTM1 positive and GSTP1 Ile/Val or Val/Val (OR = 3.71, 95% CI: 2.34–5.54) and GSTT1 positive and GSTP1 Ile/Val or Val/Val (OR = 2.66, 95% CI: 1.54–4.72) was statistically significant. Patients carrying GSTP1 Val/Val genotype were at increased risk for developing high-grade (OR = 7.68, 95% CI: 4.73–19.25) and muscle invasive (OR = 10.67, 95% CI: 6.34–21.75) bladder cancer. High risk for bladder TCC also was observed with respect to combined GSTT1 null/GSTP1 Ile/Val or Val/Val (OR = 4.76, 95% CI: 2.68–18.72) and GSTM1 null/GSTT1 null/GSTP1 Ile/Val or Val/Val (OR = 6.42, 95% CI: 4.76–14.72) genotype variant. This study suggests that the GSTP1 polymorphism and its combination with GSTM1, and GSTT1 may be associated with bladder cancer susceptibility in the Iranian population. Further confirmation in large population-based studies is needed.     

Do glutathione-S-transferase polymorphisms influence response to intravenous cyclophosphamide therapy in idiopathic nephrotic syndrome?

The response to cyclophosphamide (CP) is variable and difficult to predict in children with idiopathic nephrotic syndrome (INS). The polymorphic expression of glutathione-S-transferase (GST) may affect the remission rate after CP therapy. In this study, we evaluated the correlation of GST polymorphism and response to CP in INS. We studied GST polymorphism in 74 children with steroid-sensitive (44) and steroid-resistant (30) INS receiving intravenous cyclophosphamide (IVCP) therapy. We correlated GSTM1, GSTT1, and GSTP1 genotypes with response to IVCP. Thirty-seven (50%) out of 74 children responded to CP therapy. A synergistic effect of three genotypic combinations showed significant correlation with remission in the steroid-sensitive group. These combinations were GSTP1 and GSTM1 null genotype (p = 0.013) and GSTP1 together with GSTM1 and GSTT1 null genotypes (p = 0.026). Further, a significant difference was observed with a combination of GSTM1 and GSTT1 null genotypes and Val105 polymorphism. No association was observed among steroid-resistant patients. Our results indicate that among children with steroid-sensitive NS, there is an association with response to IVCP therapy and combination of GSTP1 Val105 polymorphism and the null genotypes of GSTT1 and GSTM1. GST polymorphism may be of significance in the management of children with INS receiving CP therapy.     

Influence of genetic polymorphisms in GSTM1, GSTM3, GSTT1 and GSTP1 on allograft outcome in renal transplant recipients

Abstract: Introduction: Glutathione S‐transferases (GSTs) are important in protection against xenobiotic compounds and toxicity caused by immunosuppressants in renal transplant recipients. In the present study we hypothesize that genetic variability in GSTM1, GSTM3, GSTP1 and GSTT1 genes may be associated with allograft outcome. Methods: The study included 223 controls and 273 transplant recipients categorized into 184 stable graft function (SGF), 57 rejection episodes (RE) and 32 delayed graft function (DGF). The polymorphism was studied using multiplex PCR and PCR‐RFLP. Results: GSTM1 null genotype showed a 3.35‐fold higher risk for rejection in SGF vs. RE category [95% confidence interval (CI) 1.27–8.84, p = 0.014]. Mutant (G) allele of GSTP1 was associated with a 5.52‐fold risk for DGF (95% CI 1.37–22.17, p = 0.016). Kaplan–Meier analysis revealed significantly lower mean time to first RE in null genotype as compared with GSTM1 present patients (Log p = 0.002). The dose adjusted C₂ levels in null genotype was higher as compared with GSTM1 present patients at one (p = 0.007) and three months (p = 0.027) post transplantation. Conclusion: Patients with variant genotype of GSTM1 and GSTP1 were at higher risk for rejection and delayed functioning of the allograft, respectively, supporting the hypothesis for involvement of GST isoform variants in allograft outcome in renal transplant recipients.     

Glutathione S-transferase gene polymorphisms (GSTM1, GSTT1, GSTP1) and prostate cancer: a case-control study in Tehran, Iran

We evaluated the relationship between polymorphisms in the glutathione S-transferases (GSTs) GSTM1, GSTT1 and GSTP1 genes and prostate cancer (PCa). PCR-restriction fragment length polymorphism assay was used to genotype the GSTM1, GSTT1, and GSTP1 polymorphisms in 168 PCa cases and 336 frequency matched controls. The GSTM1 null, and GSTT1 null genotypes were associated with an increased odds ratio (OR) for PCa (OR=3.28, 95% confidence interval (CI): 2.47-5.64; P=0.005, and OR=3.21, 95% CI: 2.52-5.64; P=0.005, respectively) (Pcorrected=0.0062). The frequency of GSTP1 Val/Val genotype was 14.3% in cases compared with 2.4% in controls, this polymorphism thus being associated with a significantly increased risk of PCa (OR=3.72, 95% CI: 1.67-5.65; P=0.002). The risk associated with the concurrent absence of both of the genes (OR=4.8, 95% CI: 2.34-6.78) was greater than the product of risk in men with either null (OR=1.52, 95% CI: 0.82-2.31) genotype combinations (P=0.001, Pcorrected=0.0045). The combination of GSTP1 Ile/Val or Val/Val polymorphism with the GSTT1 null and GSTM1 null type resulted in an OR of 6.21 (95% CI: 4.83-16.87) (P=0.0001, Pcorrected=0.0062). A higher frequency of the GSTM1 null genotype and GSTT1 null genotype was observed in patients with Gleason score >7, with an OR for GSTM1 null 4.67 (95% CI: 3.64-7.62; P=0.001) and with an OR for GSTT1 null 3.62 (95% CI: 2.31-5.74; P=0.004). The results obtained demonstrated that simultaneous presence of three potentially risk alleles (GSTM1 null, GSTT1 null and GSTP1 Val) lead to a significant OR increase for PCa.     

GSTP1, GSTM1, and GSTT1 genetic polymorphisms in patients with cryptogenic liver cirrhosis

We investigated glutathione S-transferase (GST) P1I le (105) Val, T1, and M1 polymorphisms in 45 patients with documented cryptogenic cirrhosis and 56 healthy control subjects. Polymerase chain reaction-based procedures were performed in the studied populations to confirm the genotypes of GSTT1, M1, and P1. Ile/Val and Val/Val GSTP1 genotypes were more frequent in the patients with cirrhosis (n = 39, 87%) than in the control subjects (n = 10; 18%) (odds ratio [OR] 34.04; 95% confidence interval [CI] 10.70 to 108.31, P < 0.001). Among these patients with cirrhosis, 16 were heterozygous and 23 were homozygous, whereas only one person in the control group was homozygous. The GSTM1 null genotype was also more prevalent in cirrhotic patients than in healthy control subjects (OR 6.83, 95% CI 2.53 to 18.42, P < 0.001). The rate of GSTT1 deletion did not show a significant difference between the two groups (OR 2.35, 95% CI 0.76 to 7.28, P = 0.111). To our knowledge, this is the first evidence that GSTP1 and GSTM1 polymorphisms may be related to the development of cirrhosis by unknown mechanisms. The significant association of cryptogenic cirrhosis with Val/Val GSTP1 genotype encoding a low detoxification activity protein implicates this polymorphism as a risk factor for the occurrence of the disease. Presented as an abstract at the Forty-Fourth Annual Meeting of The Society for Surgery of the Alimentary Tract, Orlando, Florida, May 19–22, 2003 (Poster of Distinction).     

An updating meta‐analysis of the GSTM1, GSTT1, and GSTP1 polymorphisms and prostate cancer: A HuGE Review

It has been postulated that individuals with GSTM1, GSTT1 deficiency and, GSTP1 (105Ile/Val transition) have increased susceptibility to carcinogens and are more likely to develop prostate cancer. In recent years, GST status has been extensively studied as a prostate cancer risk factor; however, the results are inconsistent. To re‐examine this controversy, we have undertaken an updating meta‐analysis of 29 studies with GSTM1 genotyping (4,564 prostate cancer cases and 5,464 controls), 22 studies with GSTT1 genotyping (3,837 cases and 4,552 controls), and 24 studies with GSTP1 genotyping (5,301 cases and 5,621 controls). The random effects odds ratio was 1.33 [95% confidence interval (95% CI): 1.15, 1.55; I² = 68.9%, P for heterogeneity = 0.00] for the GSTM1 null versus present genotype and 1.05 (95% CI: 0.86, 1.27; I² = 68.2%, P for heterogeneity = 0.00) for the GSTT1 null versus present genotype, and 1.06 (95% CI: 0.91, 1.24; I² = 71.5%, P for heterogeneity = 0.00) for the GSTP1‐Val versus GSTP1‐Ile allele. For GSTM1 polymorphism, similar results reached in Caucasians and Asians, with exception for Africans. No association between GSTT1 or GSTP1 polymorphisms and prostate cancer risk was detected in different racial. In conclusion, the major finding of our study suggested that GSTM1 polymorphism conferred an increasing risk of prostate cancer on a wide population basis, however, no relationship was found between GSTT1 and GSTP1 status and the risk of prostate cancer. Prostate 69:662–688, 2009. © 2009 Wiley‐Liss, Inc.     

Association of genetic polymorphism of glutathione S-transferase M1, T1, P1 and susceptibility to bladder cancer

OBJECTIVE: Glutathione-S-transferases (GSTs) are active in the detoxification of wide variety of endogenous or exogenous carcinogens. We examined the association of the GST gene polymorphism with sporadic bladder cancer patients in Northern India. MATERIAL AND METHODS: The study constituted of 106 bladder cancer cases and 370 age-matched controls. The GSTT1 and GSTM1 null genotypes were identified by multiplex PCR and GSTP1313 A/G by Polymerase Chain Reaction/Restriction Fragment Length Polymorphism method (PCR/RFLP). RESULTS: We observed non-significant association in null alleles of the GSTM1 (p = 0.611, OR = 1.12, 95% CI = 0.72-1.74 and GSTT1 (p = 0.135, OR = 1.45, 95% CI = 0.89-2.37) with risk of bladder cancer. However, the G/G genotype of the GSTP1 gene polymorphism was highly significant when compared to controls (p=0.000, OR = 7.12, 95% CI = 3.14-16.16). The combined analysis of the three risk genotypes demonstrated further increase in the risk of bladder cancer (p = 0.000, OR = 7.29 95% CI = 2.81-18.93). CONCLUSION: Our study demonstrated that GSTP1313 G/G polymorphism is a strong predisposing risk factor for bladder cancer. Combination of three GST genotypes association exhibiting gene-gene interaction further substantiates the increased risk of bladder cancer.     

Association between GSTM1, GSTT1, and GSTP1 variants and the risk of end stage renal disease

Introduction: There are some evidences indicating DNA damage by oxidant and mutant agents has an essential role in the chronic renal failure and end stage renal disease (ESRD). To investigate the possible association of GSTs variants with ESRD, we investigated the frequency of GST- T1, M1, and P1 genotypes, and the level of malondialdehyde (MDA) in patients with ESRD.

Materials and methods: The present case-control study consisted of 136 ESRD patients treated with maintenance hemodialysis and 137 gender- and age-matched, unrelated healthy controls from the population of west of Iran. The GST- T1, M1, and P1 genotypes were determined in all individuals using multiplex-PCR and PCR-RFLP. The level of MDA was measured by high-performance liquid chromatography (HPLC).

Results: We found that GSTM1 and GSTT1 null genotypes (GSTT1?/GSTM1?) increased the risk of ESRD by 1.8 times (p?<?0.001) and the increased risk of ESRD for GSTM-null (T1+-M1?) genotype was 3.04 times (p?=?0.002). ESRD patients carriers the GST (GSTM1-null?+?GSTT1-null?+?GST-null) genotypes compared to GST normal genotype increased the risk of ESRD by 3.3 (p?<?0.001) times. ESRD patients carriers of GST-null, GSTM1-null, and GSTT1-null genotypes had greater MDA concentration compared with the same genotypes of control subjects. Our results indicated that the GST-null allele (GSTT1-null/GSTM1-null) is a risk factor for ESRD and carriers of this allele have high levels of MDA.

Conclusion: Our findings indicate that oxidative stress, impairment of the antioxidant system and abnormal lipid metabolism may play a role in the pathogenesis and progression of ESRD and its related complications. These data suggest that patients with ESRD are more susceptible to vascular diseases.     

Metabolic susceptibility genes and prostate cancer risk in a southern European population: the role of glutathione S-transferases GSTM1, GSTM3, and GSTT1 genetic polymorphisms

BACKGROUND: Glutathione S-transferase (GST) metabolic enzymes may be involved in the development of human cancer. Genetic polymorphisms have been reported in GSTM1, GSTM3, and GSTT1 with functional alterations and influencing cancer risk. METHODS: We analyzed DNA samples from 335 (670 alleles) unrelated individuals, 185 community control subjects, and 150 prostate cancer (PC) patients, for GSTM1, GSTM3, and GSTT1 genotypes using polymerase chain reaction (PCR). RESULTS: The analysis of the frequencies from the 670 alleles indicates that men carrying two B-alleles (GSTM3) have increased risk for PC (OR = 5.50, 95% confidence interval (CI) 1.2-25.8; P = 0.016). Multivariate logistic regression analysis confirmed this association (OR = 5.2, 95% CI 1.1-25.0; P = 0.036). No increased PC risk was observed for men carrying any of the GSTM1 or GSTT1 genotypes (OR = 1.20, 95% CI 0.75-1.90; P = 0.420 for GSTM1 null and OR = 0.87, 95% CI 0.50-1.51; P = 0.550 for GSTM1 null). However, GSTT1 null was overrepresented in men with advanced PC disease (P = 0.038). CONCLUSIONS: Our results indicate that polymorphism in the GSTM3 may be an important biomarker for PC risk, especially in the definition of the genetic risk profile of populations of southern Europe.     

Joint effect of glutathione S‐transferase genotypes and cigarette smoking on idiopathic male infertility

Inconsistent results of association studies investigated the role of glutathione S–transferase genes in idiopathic male infertility may be explained by ethnical differences in gene–gene and gene–environment interactions. In this study, we investigated a joint contribution of GSTM1, GSTT1 and GSTP1 gene polymorphisms and cigarette smoking to the risk of idiopathic infertility in Russian men. DNA samples from 203 infertile and 227 fertile men were genotyped by a multiplex polymerase chain reaction (GSTM1 and GSTT1 deletions) and PCR‐restriction fragment length polymorphism (GSTP1 I105V) methods. The GSTP1 genotype 105IV was associated with increased risk of male infertility (OR = 1.50 95% CI 1.02–2.20 P = 0.04). Genotype combinations GSTP1 105II/GSTT1 del (G1), GSTM1 del/GSTT1 del (G2) and GSTM1 + /GSTT1 del (G3) were associated with decreased risk of male infertility (P ≤ 0.003), whereas a genotype combination GSTP1 105IV/GSTT1 + (G4) was associated with increased disease risk (P = 0.001). The genotype combinations G3 and G4 showed a significant association with infertility in smokers; however, nonsmokers carriers did show the disease risk. In conclusion, GSTM1, GSTT1 and GSTP1 genes are collectively involved in the development of idiopathic male infertility and their phenotypic effects on the disease risk are potentiated by cigarette smoking.     

Genetic polymorphism of glutathione S-transferase genes (GSTM1, GSTT1 and GSTP1) and susceptibility to prostate cancer in Northern India

OBJECTIVE: To examine the association of glutathione-S-transferase (GST) gene polymorphisms in patients with sporadic prostate cancer, in a North Indian population, as GSTs are active in detoxifying a wide variety of endogenous or exogenous carcinogens, and genetic polymorphisms of GSTM1, GSTT1 and GSTP1 have been assessed to evaluate the relative risk of various cancers. PATIENTS AND METHODS: We assessed 127 patients with prostate cancer and 144 age-matched controls, all from North India. The GSTT1 and GSTM1 null genotypes were identified by multiplex polymerase chain reaction (PCR) in peripheral blood DNA samples, and GSTP1-313 A/G polymorphism was determined by PCR/restriction fragment length polymorphism. RESULTS: There was a significant association in null alleles of the GSTM1 (odds ratio 2.239, 95% confidence interval 1.37-3.65, P = 0.001) and GSTT1 (1.891, 1.089-3.282, P = 0.026) with prostate cancer risk, and in the -313 G alleles (Val) of the GSTP1 gene (2.48, 1.51-4.08, P < 0.001). The combined analysis of these three genotypes showed a further increase in the risks of prostate cancer (7.23, 2.42-22.6, P < 0.001). CONCLUSION: The GSTP1-313 G polymorphism, and null alleles of GSTM1 and GSTT1, are strong predisposing risk factors for sporadic prostate cancer in North India.     

GSTA1, GSTM1, GSTP1, and GSTT1 polymorphisms and susceptibility to smoking-related bladder cancer: A case-control study

ObjectivesGlutathione S-transferases (GSTs) are a family of enzymes involved in detoxification. Genes encoding for GSTA1, GSTM1, GSTP1, and GSTT1 proteins are polymorphic, which can result in complete or partial loss of enzyme activity. Previous studies have associated polymorphisms of GSTA1, GSTM1, and GSTP1 genes with a higher risk of bladder cancer, but this is still controversial. Potential role of GSTA1 polymorphism in susceptibility to bladder cancer in Whites is lacking. We examined association between GSTA1, GSTM1, GSTP1, and GSTT1 gene variants and bladder cancer risk and evaluated whether they were modified by smoking.Materials and methodsA hospital-based case-control study recruited 201 incidence cases and 122 age-matched controls. Deletion polymorphism of GSTM1 and GSTT1 was identified by polymerase chain reaction method. Single nucleotide polymorphism of GSTA1 and GSTP1 was identified by restriction fragment length polymorphism method. Uniconditional multivariate logistic regression was applied to model association between genetic polymorphisms and bladder cancer risk, as well as effect modification by smoking.ResultsNo significant difference was observed in the distributions of GSTM1, GSTT1, GSTA1, and GSTP1 gene variants between patients and controls. None of the examined polymorphisms was significantly associated with bladder cancer risk independently. The results of gene–smoking interaction analyses indicated a significant combined effect of smoking and all common GST polymorphisms tested (P for trend = 0.001). However, the most significant effect on bladder cancer risk was observed in smokers carrying lower activity GSTA1-AB/BB and GSTM-null genotype (OR = 3.5, P < 0.05) compared with GSTA1-AA and GSTM1-active non-smokers. Overall, the risk observed did not significantly differ with respect to quantity of cigarettes smoked. However, heavy smokers with GSTM1-null genotype had 2 times higher risk of bladder cancer than GSTM1-null light smokers (OR = 4.8 vs. OR = 2.0) when GSTM1-active non-smokers served as reference group. Smokers carrying both GSTM1-null and GSTA1-AB + BB genotypes exhibited the highest risk of bladder cancer (OR = 2.00, P = 0.123).ConclusionsNull or low-activity genotypes of the GSTA1, GSTM1, GSTT1, and GSTP1 did not contribute independently towards the risk of bladder cancer in our patients. However, in association with smoking, both low activity GSTA1 and GSTM1-null genotype increase individual susceptibility to bladder cancer.     

Polymorphisms of GSTT1 and related genes in head and neck cancer risk

BACKGROUND: Glutathione S-transferase T1 detoxifies some environmental carcinogens while activating others and is deleted in 15% to 38% of humans. We sought to determine whether GSTT1 genotype and genotypes of several related genes are associated with risk of squamous cell carcinoma of the head and neck (HNSCC). METHODS: Somatic genotypes for GSTT1, GSTM1, GSTP1, and CYP1A1 were determined in 283 individuals with HNSCC and 208 population-based controls. RESULTS: The OR for presence of GSTT1 was 1.6 (CI, 1.1-2.5, p = 0.03). HNSCC risk was not associated with GSTM1 null genotype, the presence of the GSTP1 Val/Val genotype, or the Val/Val homozygous genotype for CYP1A1. Stratified analysis revealed disparate ORs for women (OR, 3.0; CI, 1.5-6.3) and men (OR, 1.2; CI, 0.7-2.1) for the presence of GSTT1. CONCLUSIONS: In this population, the presence of GSTT1 gene was associated with a significant increase in the risk of HNSCC. This association was particularly robust in women.     

The Effect of Glutathion S-Transferase Polymoprhisms and Anti-GSST1 Antibodies on Allograft Functions in Recipients of Renal Transplant

The balance between oxidative stress and anti-oxidant defense systems after renal transplantation may explain the development and progression of allograft dysfunction. Glutathione S-transferase (GST) decreases the damage from oxidative stress. In contrast, recipient antibodies against GSTT1 expressed on the graft are believed to cause its dysfunction. The aim of our research was to study the probable relationship to rejection between GST gene polymorphisms and anti-GSTT1 antibodies. We included 122 patients transplantations from living donors and 51 healthy individuals as controls group in our study. The patient groups were comprised of 57 patients who did and 65 who did not experienced rejection episode. Polymerase chain reactions were used to detect GSTM1 and GSTT1 polymorphisms, whereas PCR-RFLP (restriction fragment length polymorphism), for GSTP1 polymorphism. An enzyme-linked immunosorbent assay method was used for anti-GSTT1 antibody scans. There was no significant difference between the groups for allele and genotype frequencies of GSTT1, GSTM1, GSTP1 polymorphisms of the recipients, donors, and controls. Within the rejection group the frequency of patients with the GSTM1 null genotype was higher among subjects prescribed cyclosporine A versus tacrolimus (P = .029). Among the entire patient group, 46 subjects with GSTT1 null genotype were scanned for anti-GSTT1 antibody which was detected in 5 of 8 patients with an acute rejection episode (P = .04). Anti-GSTT1 antibody was observed more frequently albeit not significantly, among the cyclosporine versus tacrolimus patient group (P = .16). This study suggested that GSTM1 genotype may be important for cyclosporine detoxification and for allograft outcomes due to drug nephrotoxicity. After transplantation, antigens distinct from the HLA system such as GSTT1 protein may also be targets for alloimmune responses.     

The investıgatıon of GSTT1, GSTM1 and SOD polymorphism in bladder cancer patıents

Glutathione S transferases (GSTT1, GSTM1, GSTP1) are enzymes that activate the detoxification of endogenous and exogenous agents. The genetic polymorphism in these genes may change the response of individuals to environmental toxicants. The genetic polymorphisms of GSTT1, GSTM1, GSTP1 have been studied extensively in the determination of individual cancer risks. Some studies showed a strong relationship between polymorphism of GSTs and superoxidedismutase enzymes. Using the polymerase chain reaction (PCR) the prevalence of genetic polymorphisms of GSTT1, GSTM1 and MnSOD (Manganese Superoxide Dismurase) was investigated in 104 cases and controls to seek any association with the risk of bladder cancer. The frequency of GSTT1 +/+ polymorphism was 65% (33/51) in the cases and 79% (42/53) in the controls. The frequency of the GSTM1 +/+ polymorphism was 33% (17/51) in the cases and 58% (31/53) in the controls. The frequency of the GSTM1 null genotype was 42% (22/53) in the controls and 68% (34/51) in the patients. The frequency of the SOD AA genotype was 36% (17/51) in the cases and 33% (19/53) in the controls. There was no association between the GSTT1 and SOD polymorphism and bladder cancer incidence. The incidence of the GSTM1 null genotype was increased in bladder cancer patients compared to controls (OR = 1.755, 95% CI = 1.119–2.751).     

Association of GSTT1, GSTM1 and GSTP1 gene polymorphism with aristolochic acid nephropathy

Objective To investigate the association of genetic polymorphisms in glutathione S-transferases T1 (GSTT1), M1 (GSTM1) and P1 (GSTP1) with aristolochic acid nephropathy (AAN) of Chinese people in Wenzhou of China. Methods Fifty-nine patients with AAN (AAN group) including 29 male and 30 female as well as 157 healthy ethnically matched controls (control group) including 93 male and 64 female were enrolled in this study. The genotypes of GSTT1, GSTM1 and GSTP1 were determined by multiple PCR and confronting two-pair primers PCR (CTPP-PCR). Results The genotype frequencies of GSTP1 were in Hardy-Weinberg equilibrium. Compared with the healthy controls, the frequency of GSTT1 null genotype was significantly higher in the patients with AAN (66.1％ vs 48.4％，P<0.05). Risk of AAN for individuals with GSTT1 null genotype was 1.747 fold of those without GSTTI null genotype (95% CI=0.818-3.731). The frequency of GSTM1 null genotype, GSTP1 variant genotypes and GSTP1 G allele in the patients and in the controls were 40.7％, 28.8％, 16.1％ and 47.8％, 31.8％, 17.5％, respectively, which were not significantly different. No significant differences were found in prevalence of GSTM1 and GSTP1 gene distribution between patients and controls. Conclusion GSTT1 gene polymorphism appears to be associated with susceptibility to AAN in Southern China.     

Association of polymorphisms in glutathione S-transferase genes (GSTM1, GSTT1, GSTP1) with idiopathic azoospermia or oligospermia in Sichuan,China

The reported effects of the glutathione S-transferase (GSTs) genes (GSTM1, GSTT1, and GSTP1) on male factor infertility have been inconsistent and even contradictory. Here, we conducted a case-control study to investigate the association between functionally important polymorphisms in GST genes and idiopathic male infertility. The study group consisted of 361 men with idiopathic azoospermia, 118 men with idiopathic oligospermia, and 234 age-matched healthy fertile male controls. Genomic DNA was extracted from the peripheral blood, and analyzed by polymerase chain reaction and restriction fragment length polymorphism analysis. There was a significant association between the GSTP1 variant genotype (Ile/Val + Val/Val) with idiopathic infertility risk (odds ratio [OR]: 1.53; 95% confidence interval [CI]: 1.11–2.11; P = 0.009). Similarly, a higher risk of infertility was noted in individuals carrying a genotype combination of GSTT1-null and GSTP1 (Ile/Val + Val/Val) (OR: 2.17; 95% CI: 1.43–3.31; P = 0.0002). These results suggest an increased risk of the GSTP1 variant genotype (Ile/Val + Val/Val) for developing male factor infertility. Our findings also underrate the significance of the effect of GSTM1 and/or GSTT1 (especially the former) in modulating the risk of male infertility in males from Sichuan, southwest China.     

Antioxidant enzymes, presbycusis, and ethnic variability

Objective

A proposed mechanism for presbycusis is a significant increase in oxidative stress in the cochlea. The enzymes glutathione S-transferase (GST) and N-acetyltransferase (NAT) are two classes of antioxidant enzymes active in the cochlea. In this work, we sought to investigate the association of different polymorphisms of GSTM1, GSTT1, and NAT2 and presbycusis and analyze whether ethnicity has an effect in the genotype-phenotype associations.

Study Design

Case-control study of 134 DNA samples.

Setting

University-based tertiary care center.

Subjects and Methods

Clinical, audiometric, and DNA testing of 55 adults with presbycusis and 79 control patients with normal hearing.

Results

The GSTM1 null genotype was present in 77 percent of white Hispanics and 51 percent of white non-Hispanics (Fisher's exact test, 2-tail, P = 0.0262). The GSTT1 null genotype was present in 34 percent of control patients and in 60 percent of white presbycusis subjects (P = 0.0067, odds ratio [OR] = 2.843, 95% confidence interval [95% CI] = 1.379-5.860). The GSTM1 null genotype was more frequent in presbycusis subjects, i.e., 48 percent of control patients and 69 percent of white subjects carried this deletion (P = 0.0198, OR = 2.43, 95% CI = 1.163-5.067). The NAT2*6A mutant genotype was more frequent among subjects with presbycusis (60%) than in control patients (34%; P = 0.0086, OR = 2.88, 95% CI = 1.355-6.141).

Conclusion

We showed an increased risk of presbycusis among white subjects carrying the GSTM1 and the GSTT1 null genotype and the NAT*6A mutant allele. Subjects with the GSTT1 null genotypes are almost three times more likely to develop presbycusis than those with the wild type. The GSTM1 null genotype was more prevalent in white Hispanics than in white non-Hispanics, but the GSTT1 and NAT2 polymorphisms were equally represented in the two groups.