Glutathione S-transferase T1 Genotypes Research Articles

GST polymorphism as a predictive biomarker for modulating the susceptibility to chronic obstructive pulmonary disease: A North Indian study.

Chronic obstructive pulmonary disease (COPD) is commonly characterized by shortness of breath, coughing or expectoration. Smoking is the leading cause of COPD development, but only a small percentage of smokers develop symptoms, implying a genetic component. Glutathione S-transferase enzymes are responsible for detoxifying cigarette smoke components. The role of glutathione S-transferase T1 (GSTT1) and glutathione S-transferase M1 (GSTM1) gene polymorphism was assessed with COPD susceptibility and associated clinical parameters in the North Indian population. This was a cross-sectional study involving 200 COPD patients and 200 healthy individuals, with peripheral blood sampling and adequate questionnaires. Multiplex PCR was used for genotyping GSTT1 and GSTM1 gene polymorphism. Logistic regression was used to calculate the odds ratio and 95% confidence intervals to assess the COPD risk and GST polymorphisms. The GSTT1 gene deletion rate was higher in COPD cases (34.5%) than in healthy individuals (20.5%). A statistical relationship between the GSTT1(-) null genotype and COPD risk was observed (odds ratio=2.04, 95% CI=1.30-3.20, P=0.0019). After adjusting for covariates like age, sex and smoking status, a significant association was found for GSTT1(-) null genotype and COPD risk (adjusted odds ratio=2.90, 95% CI=1.43-5.87, P=0.003). The GSTT1(-) genotype was also significantly correlated with clinical parameters for COPD risk. Another primary observation was that females with the GSTT1(-) null genotype were more vulnerable to COPD than males with the same gene deletion. The GSTT1(-) null genotype strongly correlates with COPD development, while no association was observed in the GSTM1(-) null genotype in the North Indian population.

Null genotypes of Glutathione S-transferase M1 and T1 and risk of oral cancer: A meta-analysis.

Glutathione S-transferase M1 (GSTM1) and Glutathione S-transferase T1 (GSTT1) null genotypes have been considered risk factors for many cancers. Numerous studies have been conducted to evaluate the association of null genotype of GSTM1 and GSTT1 with increased susceptibility to oral cancers, and these have produced inconsistent and inconclusive results. In the present study, the possible association of oral cancer(OC) with GSTM1 and GSTT1 null genotypes was explored by a meta analysis. A meta-analysis was conducted on published original studies retrieved from the literature using a bibliographic search from two electronic databases: MEDLINE (National library of medicine, USA) and EMBASE. The pooled odds ratio and presence of publication bias in those studies were evaluated. A total of 49 studies concerning oral cancer (OC) were identified for GSTM1 null genotype. Similarly, 36 studies were identified for GSTT1 null genotype. The pooled OR was 1.551(95% confidence interval [CI]: 1.355-1.774) for the GSTM1 null genotype, while for GSTT1 null genotype, the pooled OR was 1.377 (95% CI: 1.155-1.642). No evidence of publication bias was detected among the included studies. The results suggest that the Glutathione S-transferase M1 and Glutathione S-transferase T1 null genotypes significantly enhances the risk of developing oral cancer by a substantial percentage.

Glutathione S-Transferase T1 Mismatch Is a Risk Factor for Chronic Ductopenic Rejection of Liver Allografts.

The underlying causes of chronic rejection (CR) after liver transplantation (LT) are not completely known. The main aim of this study was to explore the involvement of the minor histocompatibility antigen glutathione S-transferase T1 (GSTT1) in CR. We retrospectively studied 611 patients who underwent LTs at University Hospital Virgen del Rocío between 2003 and 2016 with a median follow-up of 7.4±4.2 years. The GSTT1 genotype was determined by polymerase chain reaction. We defined GSTT1 mismatch as a specific donor/recipient combination in which a recipient who was homozygous for the deletion allele received a transplant from a positive donor. The prevalence of CR in our whole cohort was 11.6% (71/611), and the prevalence in the GSTT1-mismatched group was 18.8% (16/85) versus 10.5% (55/526) in the GSTT1-matched group. In the cyclosporine A (CsA) group, the prevalence was 26.3% (26/99), much higher than the 8.8% (45/512) observed in the tacrolimus (Tac) group. For statistical analysis, the patients were distributed into 2 groups: group 1, regarded as GSTT1 mismatched, which included the donor (D)+/recipient (R)- allelic combination; and group 2, regarded as GSTT1 matched, which included the other allelic combinations of D+/R+, D-/R-, and D-/R+. All relevant clinical information was collected, and a diagnosis of CR was always confirmed by liver biopsy. GSTT1 mismatch (hazard ratio [HR], 1.99; 95% confidence interval [CI], 1.08-3.66; P=0.03) and use of CsA/Tac (P<0.001) were independent risk factors for CR. CR increased the risk of mortality (HR, 2; 95% CI, 1.2-3.6; P=0.01). Out of the 71 CR patients, 12 (16.9%) needed retransplantation. In conclusion, the GSTT1 D+/R- allelic mismatch is an independent risk factor for CR. A long follow-up of LT patients is recommended because the incidence of CR in adults seems to be underestimated.

An updated meta-analysis of the relationship between glutathione S-transferase T1 null/presence gene polymorphism and the risk of lung cancer.

There were many reports published on the relationship between glutathione S-transferase T1 (GSTT1) null/presence gene polymorphism and the risk of lung cancer in these years. In previous, we conducted a meta-analysis to evaluate the relationship between GSTT1 null/presence gene polymorphism and the risk of lung cancer. This study was conducted to update it. The association studies were identified from PubMed and Cochrane Library on March 1, 2016. Sixty-three reports were recruited into this meta-analysis for the association of null genotype of GSTT1 with lung cancer susceptibility, consisting of 21,220 patients with lung cancer and 21,496 controls. There was a marked association between GSTT1 null genotype and lung cancer risk in overall populations and in Asians (overall populations: Odds ratio [OR] = 1.17, 95% confidence interval [95% CI]: 1.07-1.28, P = 0.006; Asians: OR = 1.41, 95% CI: 1.23-1.62, P < 0.00001). However, GSTT1 null genotype was not associated with the risk of lung cancer in Caucasians, Brazilian population, and Africans. GSTT1 null genotype is associated with the lung cancer risk in overall populations and in Asians.

Association of the Glutathione S-transferase T1 Null Genotype with Risk of Gastric Cancer: a Meta-analysis in Asian Populations.

A large number of studies have been published to investigate the association between the null genotype of glutathione S-transferase T1 (GSTT1) with gastric cancer. However, the results were inconsistent and conflicting. The aim of this study was to estimate the relationship between this polymorphism in the GSTT1 gene and gastric cancer risk in Asian populations by meta-analysis. A literature search was performed in PubMed, Embase, Chinese Biomedical database (CBM), Weipu database, Wanfang database, and China National Knowledge Infrastructure database (CNKI). Statistical analysis was conducted by using Review Manager 5.3. Thirty-nine studies with a total of 7,737 gastric cancer cases and 10,823 controls were included in this meta-analysis. The meta-analysis of total studies showed that the null genotype in GSTT1 was associated with increased risk of gastric cancer in Asians (OR=1.19, 95% CI=1.08-1.31, p=0.0002). Subgroup analysis showed a significant relationship between GSTT1 null genotype and gastric cancer in East-Asians, as well as in subgroup analysis of hospital-based design. On subgroup analysis by smoking status, alcohol status, Helicobacter pylori infection status, and histology type, no significant association of this polymorphism with susceptibility to gastric cancer was found. In conclusion, the results showed that the null genotype of GSTT1 is significantly associated with an increased risk in gastric cancer in Asian populations.

GST M1-T1 null allele frequency patterns in geographically assorted human populations: a phylogenetic approach.

Genetic diversity in drug metabolism and disposition is mainly considered as the outcome of the inter-individual genetic variation in polymorphism of drug-xenobiotic metabolizing enzyme (XME). Among the XMEs, glutathione-S-transferases (GST) gene loci are an important candidate for the investigation of diversity in allele frequency, as the deletion mutations in GST M1 and T1 genotypes are associated with various cancers and genetic disorders of all major Population Affiliations (PAs). Therefore, the present population based phylogenetic study was focused to uncover the frequency distribution pattern in GST M1 and T1 null genotypes among 45 Geographically Assorted Human Populations (GAHPs). The frequency distribution pattern for GST M1 and T1 null alleles have been detected in this study using the data derived from literatures representing 44 populations affiliated to Africa, Asia, Europe, South America and the genome of PA from Gujarat, a region in western India. Allele frequency counting for Gujarat PA and scattered plot analysis for geographical distribution among the PAs were performed in SPSS-21. The GST M1 and GST T1 null allele frequencies patterns of the PAs were computed in Seqboot, Gendist program of Phylip software package (3.69 versions) and Unweighted Pair Group method with Arithmetic Mean in Mega-6 software. Allele frequencies from South African Xhosa tribe, East African Zimbabwe, East African Ethiopia, North African Egypt, Caucasian, South Asian Afghanistan and South Indian Andhra Pradesh have been identified as the probable seven patterns among the 45 GAHPs investigated in this study for GST M1-T1 null genotypes. The patternized null allele frequencies demonstrated in this study for the first time addresses the missing link in GST M1-T1 null allele frequencies among GAHPs.

Null genotype of GSTT1 contributes to increased Parkinson's disease risk in Caucasians: evidence from a meta-analysis.

Conflicting results in previous case-control studies on the association between Glutathione S-transferase T1 (GSTT1) gene polymorphism and Parkinson's disease (PD) risk have been reported, so we conducted this meta-analysis. We searched and extracted data from 3 Chinese and 3 English web-based electronic databases to evaluate the associations by odds ratio (OR) and its 95% confidence interval (CI) under the recessive genetic comparison model (null genotype vs. present genotype). We also conducted subgroup analyses by ethnicity and adjusted status of OR, respectively. Meta-analyses and subgroup analyses of larger studies (sample size ≥300) were also reanalyzed. When 18 eligible studies (3,963 PD cases and 5,472 controls) were pooled to analyze the association, we found no statistically significant result (OR 1.24, 95% CI 0.96-1.60). In the subgroup analyses by ethnicity, there was statistically significant association between the null genotype of GSTT1 and PD risk among Caucasians, while the associations were not found among Asians and Latinos. In the subgroup analyses by adjusted status of OR, there were no significant associations both in studies with crude OR and adjusted OR. Meta-analyses and subgroup analyses of larger studies (sample size ≥300) were also confirmed the associations mentioned above. Power analysis indicated only meta-analysis of Caucasians had enough evidence to claim the association. In conclusion, the meta-analysis suggests that the null genotype of GSTT1 contributes to PD risk in Caucasians, and no association in Asians is needed more studies to confirm.

Association between glutathione S-transferase T1 null genotype and risk of lung cancer: a meta-analysis of 55 studies

The relationship between glutathione S-transferase T1 (GSTT1) gene polymorphism and the risk of lung cancer from the published reports are still conflicting. This study was conducted to evaluate the relationship between GSTT1 polymorphism and the risk of lung cancer. A comprehensive research was conducted through the databases, and 55 studies were recruited into this meta-analysis for the association of null genotype of GSTT1 with lung cancer susceptibility, consisting of 15,140 patients with lung cancer and 16,662 controls. There was a significant association between GSTT1 null genotype and lung cancer risk in the overall populations (OR = 1.138, 95% CI = 1.032-1.255, P heterogeneity = 0.000, P = 0.009). Furthermore, GSTT1 null genotype was associated with the lung cancer risk in Asians (OR = 1.469, 95% CI = 1.228-1.757, P heterogeneity = 0.000, P = 0.000). However, GSTT1 null genotype was not associated with the risk of lung cancer in Caucasians and Africans. In conclusion, GSTT1 null genotype is associated with the lung cancer in overall populations and in Asians.

Association between GSTP1, GSTM1, GSTT1 genetic polymorphisms and urinary styrene phenyl hydroxyethyl mercapturic acids level

To investigate the relationship between genetic polymorphisms of glutathione S-transferase P1 (GSTP1), glutathione S-transferase M1 (GSTM1), and glutathione S-transferase T1 (GSTT1) and urinary level of mercapturic acids of styrene (PHEMAs) in workers exposed to styrene. One hundred and twenty-six workers exposed to styrene were selected as exposure group, and 150 workers without styrene exposure as the control group; all the workers came from a locomotive shell production factory in Shandong Province, China. The PCR-RFLP technique was applied to analyze the individual genetic polymorphisms of GSTP1; the multiplex PCR technique was used to investigate the genetic polymorphisms of GSTM1 and GSTT1; the relationship between genetic polymorphisms of GSTP1, GSTM1, and GSTT1 and urinary level of PHEMAs in workers exposed to styrene was statistically analyzed. The three genotypes investigated in the study had a distribution in accordance with the Chinese population. With exposure to high- concentration styrene, the individuals carrying GSTP1 (exon5, A105G) AA genotype (wildtype) had a significantly higher urinary level of PHEMAs (43.58 mg/g) than those with mutant genotypes AG (29.769 mg/g) and GG (30.245 mg/g); the urinary level of PHEMAs in individuals carrying wild-type GSTM1 genotype was significantly higher than that in individuals carrying deficient-type GSTM1 genotype (40.197 mg/g vs 28.866 mg/g, P < 0.05); no significant difference in urinary level of PHEMAs was found between individuals carrying wild-type GSTT1 genotype and deficient-type GSTT1 genotype. There was no significant relationship between the three gene polymorphisms and urinary level of PHEMAs in the control group. The genetic polymorphisms of GSTP1 and GSTM1 may be related to urinary level of PHEMAs in workers exposed to styrene.

A meta-analysis of the relationship between glutathione S-transferase T1 null/presence gene polymorphism and the risk of lung cancer including 31802 subjects

The relationship between glutathione S-transferase T1 (GSTT1) null/presence gene polymorphism and the risk of lung cancer from the published reports are still conflicting. This study was conducted to evaluate the relationship between GSTT1 null/presence gene polymorphism and the risk of lung cancer using meta-analysis method. The association studies were identified from PubMed, and Cochrane Library on July 1, 2012, and eligible investigations were included and synthesized using meta-analysis method. 51 reports were recruited into this meta-analysis for the association of null genotype of GSTT1 with lung cancer susceptibility, consisting of 15,140 patients with lung cancer and 16,662 controls. There was a marked association between GSTT1 null genotype and lung cancer risk in overall populations (OR = 1.15, 95 % CI 1.04-1.27, P = 0.007). Furthermore, GSTT1 null genotype was associated with the lung cancer risk in Asians (OR = 1.47, 95 % CI 1.23-1.76, P < 0.0001). However, GSTT1 null genotype was not associated with the risk of lung cancer in Caucasians, Brazilian population and Africans. In conclusion, GSTT1 null genotype is associated with the lung cancer in overall populations and in Asians.

Quantitative assessment of the influence of glutathione S-transferase T1 null variant on gastric cancer risk

Glutathione S-transferase T1 (GSTT1) catalyzes reactions between glutathione and lipophilic compounds with electrophilic centers, leading to neutralization of toxic compounds, xenobiotics, and products of oxidative stress. In the past decade, a number of case-control studies have been carried out to investigate the relationship between the GSTT1 null polymorphism and gastric cancer (GC), but the results have been inconclusive. To investigate this inconsistency, we performed a meta-analysis of 46 studies involving a total of 9012 GC cases and 14,215 controls for null variant of the GSTT1 gene to evaluate the effect of GSTT1 on genetic susceptibility for GC. Potential sources of heterogeneity including ethnicity, source of control, and sample size were also assessed. Overall, significantly increased GC risk was associated with GSTT1 null polymorphism with OR of 1.20 (95% CI, 1.10-1.32; P < 0.05). In the subgroup analysis by ethnicity, significantly increased risks were found in East Asians and Indians, while no significant associations were found among Caucasian, and Middle Eastern and African populations. By pooling data from 19 studies that considered combinations of GSTT1 and GSTM1 genotypes, a statistically significant increased risk for GC (OR = 2.04, 95% CI, 1.49-2.64; P < 0.05) was detected for individuals with dual deletion in both genes compared with positive genotypes. In addition, we found that cigarette smoking and alcohol drinking may modified the association of GSTT1 null genotypes with the risk of GC. In conclusion, this meta-analysis suggests that GSTT1 null polymorphism is associated with elevated GC risk, but these associations vary in different ethnic populations.

GSTT1 null genotype contributes to hepatocellular carcinoma risk: a meta-analysis

Studies investigating the association between genetic polymorphism of glutathione S-transferase T1 (GSTT1) and hepatocellular carcinoma (HCC) risk have reported conflicting results. Therefore, we conducted this meta-analysis to provide more precise evidence. Databases including PubMed, Embase, SCOPUS, ISI Web of Science, and Wangfang were searched for relevant studies. Potential sources of heterogeneity were also assessed by subgroup analysis. Funnel plots and Egger's linear regression were used to test publication bias among the articles. Finally, a total of 28 studies involving 3,897 HCC patients and 6,117 controls were included in this meta-analysis. In a combined analysis, the summary odds ratio for HCC of the GSTT1 null genotype was 1.43 (95% confidence interval (CI) 1.22–1.68, P < 10(−5)). In the subgroup analysis by ethnicity, significantly increased risks were found in East Asians for GSTT1 null polymorphism, while no significant associations were found among Caucasian, South Asian, and African populations. When stratified by a source of controls, both population- and hospital-based studies get consistent positive results. By pooling data from 10 studies (1,639 cases and 2,224 controls) that considered combinations of GSTT1 and GSTM1 genotypes, a statistically significant increased risk for HCC (odd ratio = 1.85, 95% CI 1.37–2.49) was detected for individuals with combined deletion mutations in both genes compared with positive genotypes. No evidence of publication bias was observed. Our result suggests that the GSTT1 null genotype contributes to an increased risk of HCC in East Asians and that interaction between unfavorable GSTs genotypes may exist.

Glutathione S-transferase T1 gene polymorphism and colorectal cancer risk: An updated analysis

The association between glutathione S-transferase T1 (GSTT1) gene polymorphisms and colorectal cancer (CRC) susceptibility is still controversial. In order to clarify the effect of GSTT1 genotype on the CRC risk, we carried out an updated meta-analysis of published case-control studies to provide more precise evidence. Two investigators independently searched the databases of Pubmed, EMBASE and China National Knowledge Infrastructure (CNKI) up to October 15, 2012. Crude odds ratios (OR) and 95% confidence intervals (CI) were calculated to investigate the strength of the association in a fixed- or random-effects model depending on statistical heterogeneity. Forty-six case-control studies with 15,373 colorectal cancer cases and 21,238 controls were included. Overall, the pooled results indicated that GSTT1 null genotype was significantly associated with increased CRC risk (OR=1.21, 95% CI=1.10-1.33). When stratifying for ethnicity and control sources, we also observed positive association between GSTT1 null genotype and increased risk of CRC. When stratifying by the location, we found there was a statistically significant association in the rectal cancer (OR=1.28, 95% CI=1.01-1.64), but not in colon cancer (OR=1.27, 95% CI=0.94-1.73). Subgroup analyses for Dukes stage, histological differentiation of CRC and smoking habit did not reveal any significant differences in genotype distribution. In addition, we observed a strong correlation between increased CRC risk and the combined GSTM1 and GSTT1 null genotype. This meta-analysis suggests that the GSTT1 null genotype may contribute to increased risk of colorectal cancer. More well-designed studies based on larger population are needed to confirm our results.

Null genotype of glutathione S-transferase T1 contributes to increased risk of gastric cancer in Asian population

Numerous studies were published to investigate the relationship between the glutathione S-transferase T1 (GSTT1) null genotype and risk of gastric cancer in Asians, but the conclusions from those studies were conflicting. To get a more precise estimation on the possible association, we performed a meta-analysis of published data. A comprehensive literature was conducted and 27 case-control studies with 14,905 individuals were finally included, involving a total of 6,270 cases and 8,635 controls. The strength of the association between GSTT1 polymorphism and gastric cancer risk was estimated by calculating the pooled odds ratio with its 95 % confidence interval (95 % CI). A meta-analysis of total 27 studies showed that GSTT1 null genotype was obviously associated with increased risk of gastric cancer in Asians (random effect odds ratio (OR) =1.29, 95 % CI 1.16-1.44, P OR<0.001). A subgroup analysis of 14 studies with large sample size also showed an obvious association between GSTT1 null genotype and increased risk of gastric cancer in Asians (fixed effect OR=1.14, 95 % CI 1.06-1.23, P OR=0.001). In conclusion, the meta-analysis suggests that null genotype of GSTT1 contributes to increased risk of gastric cancer in Asian population.

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.

Impact of glutathione S-transferase T1 gene polymorphisms on acute cellular rejection in living donor liver transplantation

It has previously been demonstrated that glutathione S-transferase T1 (GSTT1) genetic mismatch between recipient and donor is a risk factor for developing immune-mediated hepatitis following liver transplantation and for antibody-mediated rejection in renal transplantation. Little is known whether the GSTT1 gene polymorphism affects the incidence of acute cellular rejection (ACR) following living donor liver transplantation (LDLT). Patients underwent LDLT at Nagoya University or Kyoto University, Japan, between 2004 and 2009. Genotyping of GSTT1 genes (null or present genotype) was conducted in recipients and donors. A total of 155 LDLT cases were examined. Forty-seven recipients (30.3%) developed early ACR. There was no association of recipient GSTT1 genotype with ACR incidence. However, ACR incidence was significantly higher in recipients transplanted from GSTT1 present genotype donors than in those transplanted from GSTT1 null genotype donors [odds ratio (OR)=2.64, 95% confidence interval (CI)=1.12–5.83, p=0.016]. Moreover, GSTT1 recipient/donor genotype mismatch (present/null or null/present) was significantly associated with ACR development (OR=2.28, 95% CI=1.12–4.61, p=0.022). The genotyping of GSTT1 in recipients and donors might be useful to stratify the liver transplant recipients according to risk of ACR.

Null Genotype of GSTT1 Contributes to Esophageal Cancer Risk in Asian Populations: Evidence from a Meta-analysis

Glutathione S-transferase T1 (GSTT1), a phase-II enzyme, plays an important role in detoxification of carcinogen electrophiles. Many studies have investigated the association between GSTT1 polymorphism and esophageal cancer risk in Asian populations, but its actual impact is not clear owing to apparent inconsistencies among those studies. Thus, a meta-analysis was performed to explore the effect of GSTT1 polymorphism on the risk of developing esophageal cancer. A literature search of PubMed, Embase, and Wanfang databases up to August 2012 was conducted and 15 eligible papers were finally selected, involving a total of 1,626 esophageal cancer cases and 2,216 controls. We used the pooled odds ratio (OR) with its corresponding 95% confidence interval (95%CI) to estimate the association of GSTT1 polymorphism with esophageal cancer risk. Subgroup analyses and sensitivity analyses were performed to further identify the association. Meta-analysis of total studies showed the null genotype of GSTT1 was significantly associated with an increased risk of esophageal cancer in Asians (OR=1.26, 95%CI=1.05-1.52, POR=0.015, I2=42.7%). Subgroup analyses by sample size and countries also identified a significant association. Sensitivity analysis further demonstrated a relationship of GSTT1 polymorphism to esophageal cancer risk in Asians. The present meta-analysis of available data showed a significant association between the null genotype of GSTT1 and an increased risk of esophageal cancer in Asians, particularly in China.

Relationship Between GSTT1 Gene Polymorphism and Hepatocellular Carcinoma in Patients from China

The results from studies on associations of the glutathione S-transferase T1 (GSTT1) gene polymorphism and hepatocellular carcinoma (HCC) risk in Chinese populations are still conflicting. This meta- analysis was performed to evaluate the relationship in detail. Eligible reports were recruited into this meta-analysis from the databases of PubMed, Embase, Cochrane Library and CBM-disc (China Biological Medicine Database). Results were expressed with odds ratios (OR) for dichotomous data, and 95% confidence intervals (CI) were also calculated. Eighteen investigations were identified for the analysis of association between polymorphic deletion of GSTT1 and HCC, consisting of 2,693 patients with HCC and 4,696 controls. Null genotype of GSTT1 was associated with HCC susceptibility in Chinese (OR=1.53, 95%CI: 1.28-1.82; P<0.00001). The GSTT1 null genotype is associated with HCC susceptibility in Chinese.

A preliminary study on the influence of glutathione S transferase T1 (GSTT1) as a risk factor for late onset Alzheimer's disease in North Indian population

IntroductionOxidative stress plays key role in pathogenesis of Alzheimer's disease. Glutathione S-transferases (GSTs), a family of phase-II isoenzymes, play a critical role in providing protection against electrophiles and products of oxidative stress. Among different classes of GSTs, GSTM1 (Mu) and GSTT1 (theta) are found to be genetically deleted which results in decreased expression of the concerned enzyme. This study aims at preliminary analysis of the frequency of deletion of GSTM1 and GSTT1 and their association with late-onset Alzheimer's disease. Material and methodsIn this study, association of the deletion type polymorphism of GST M1 and T1 as possible risk factors for dementia of Alzheimer's type was studied in 50 patients and 100 controls. Dementia was diagnosed by Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria, Mini Mental State Examination (MMSE) and Clinical Dementia Rating (CDR) scale. Genotyping was done by multiplex Polymerase Chain Reaction (PCR). Associations between null genotype of either GSTM1 and GSTT1 or both with Alzheimer's disease were analyzed by Chi-Square test. ResultsDeletion of GSTT1 was found significantly associated with Alzheimer's disease (χ2=5.08, p=0.02*). ConclusionsThe odds of Alzheimer's disease in null GSTT1 is found to be increased by 2.47 times in comparison to positive GSTT1.

Genetic polymorphisms of glutathione S-transferase T1 (GSTT1) and M1 (GSTM1) in selected populations of Afghanistan

Genetic polymorphisms in genes encoding glutathione S-transferase T1 (GSTT1, a member of class theta) and M1 (GSTM1, a member of class mu) have been defined. Previous studies have revealed that there was significant difference between populations for allelic frequency of several members of GSTs. In order to find the prevalence of null genotypes of GSTM1 and GSTT1 in Afghanis populations the present study was carried out. The total study subjects consisted of 656 unrelated healthy Afghanis refugees living in Fars province (southern Iran). From these 257, 217, 120, and 62 individuals were Pashtuns, Tajiks, Hazaras, and Uzbeks, respectively. Genetic polymorphisms for GSTT1 and GSTM1 were detected by multiplex PCR. The prevalence of null genotype of GSTM1 in Pashtuns, Tajiks, Hazaras, and Uzbeks was 42.4, 48.4, 52.5, and 40.3 %, respectively. There was no significant difference between these populations for the genotypic distribution of the GSTM1 polymorphism (χ(2) = 4.67, df = 3, P = 0.197). The frequency of GSTT1 null genotype in Pashtuns, Tajiks, Hazaras, and Uzbeks was 7.4, 25.3, 25.0, and 29.0 %, respectively. The observed difference between populations for prevalence of GSTT1 null genotype was statistically significant (χ(2) = 35.54, df = 3, P < 0.001). In comparison with European and Asian populations, Afghanistan populations like Iranian populations showed intermediate frequency for GSTT1 and GSTM1 null genotypes.