Glutathione S-transferase T1 Null Genotype 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.

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.

Role of Glutathione-S-Transferases in Gallbladder Cancer and Cholelithiasis Susceptibility and Meta-Analysis

Glutathione-S-transferase T1 (GSTT1) and glutathione-S-transferase M1 (GSTM1) genes are associated with increase susceptibility to developing different types of cancers. The aim of present study was to investigate the role of genetic variants of GSTM1 and GSTT1 in gallbladder cancer (GBC) and cholelithiasis in Kashmir valley. Genotyping was done by multiplex polymerase chain reaction in 100 GBC, 100 cholelithiasis, and 150 controls adjusted by age and sex. We also performed a meta-analysis of published studies on GSTM1 and GSTT1 to evaluate the association between the GSTM1 and GSTT1 polymorphisms and GBC. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using random- or fixed-effects model. In the present study, no association was observed between GSTM1 null and GSTT1 null genotypes and GBC and cholelithiasis. Meta-analysis results showed that GSTM1 null genotype was associated with GBC risk (P = 0.042). Subgroup analysis by ethnicity showed that GSTM1 null (P = 0.024) and GSTT1 null genotype (P = 0.037) were significantly associated with risk of GBC in Asians. This is the first study to investigate the role of genetic variants of GSTM1 and GSTT1 in GBC in Kashmir valley and cholelithiasis in the world.

Glutathione-S-transferase M1 polymorphism and pro-inflammatory cytokines tumour necrosis factor-α and interleukin-1β are associated with preeclampsia in Serbian women.

Preeclampsia has a multifactorial origin with genetic, immunological, and environmental factors described as main contributors to its onset. This study aimed to investigate glutathione-S-transferase M1 (GSTM1) and glutathione-S-transferase T1 (GSTT1) gene polymorphisms, the expression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), and the potential relationship between GST polymorphisms and cytokine expression levels in preeclampsia and uncomplicated pregnancy. This prospective case-control study included 50 women with preeclampsia and 50 healthy pregnant women. DNA and RNA were extracted from women leukocytes. Deletion polymorphisms were analyzed by PCR, while cytokine mRNA expression was analyzed by real-time PCR. GSTM1 null genotype with present GSTT1 increased the risk for preeclampsia development. Deletion of GSTT1 without deletion of GSTM1 increased the risk for early preeclampsia. Relative mRNA expression of TNF-α was significantly higher in preeclampsia compared to healthy pregnant women (P=0.006). Expression of IL-1β was significantly higher in severe and late preeclampsia compared to the control group (P=0.005, P=0.007, respectively). A significant positive correlation between TNF-α and IL-1β was observed (Spearman's ρ=0.312, P=0.028) and between IL-1β and IL-6, in preeclampsia group (Spearman's ρ=0.296, P=0.037). IL-1β was significantly increased in patients with GSTT1 null genotype (P=0.015) while IL-6 was increased in patients with GSTM1 null genotype (P=0.015). GSTM1 null genotype represents a risk factor for preeclampsia development, while GSTT1 null genotype favors early preeclampsia. Preeclampsia is also associated with increased expression of pro-inflammatory cytokines, predominantly TNF-α and IL-1β.

Glutathione S-Transferase M1 and T1 polymorphisms and hypertension risk: an updated meta-analysis.

Recently, Glutathione S-transferase M1 (GSTM1), glutathione S-transferase T1 (GSTT1), and their interaction with hypertension risk have been focused on. However, the results of previous studies have been inconsistent. Hence, the present meta-analysis was performed to explore the association. Twenty-two case-control studies met the inclusion criteria for GSTM1 (including 3577 hypertension cases and 3784 controls), twenty-two for GSTT1 (including 3741 cases and 4444 controls), and nine for their combined effects (including 1073 cases and 781 controls). Pooled analyses on the association between GSTM1 present/null polymorphism and hypertension risk were observed to be insignificant in overall and subgroup analyses. The individual who carries the GSTT1 null-genotype had a statistically significant overall population (OR = 1.28, 95% CI: 1.03, 1.60), Indians (OR = 2.45, 95% CI: 1.08, 5.59), and hospital-based controls (OR = 1.53, 95% CI: 1.21, 1.94). For the GSTM1-GSTT1 interaction, we found that the GSTM1/GSTT1 double-null-genotype was significantly associated with hypertension risks (double-null vs. double-present: OR = 2.68, 95% CI: 1.06, 6.81). To summarize, this meta-analysis indicates that Indians with the GSTT1 null-genotype has a raised hypertension risks; the GSTM1 null/GSTT1 null-genotype is association with raised hypertension risks, while the GSTM1 null-genotype is not associated with hypertension risks. In addition, I2 > 75% cannot be eliminated for GSTM1 in Indians or Asians, hence, it will be very important to explore the GSTM1 null-genotype and hypertension susceptibility in Indians and Asians for a large new sample, on population-based control study.

Glutathione S-transferase M1 and T1 polymorphisms, and their interactions with smoking on risk of low birth weight: a meta-analysis

Background: Published data regarding the association between glutathione S-transferase M1 (GSTM1) and glutathione S-transferase T1 (GSTT1) gene polymorphisms and risk of low birth weight (LBW) remains inconclusive, and data on the interactions between the two gene polymorphisms and smoking for LBW susceptibility is lacking. To clarify these associations, a meta-analysis was conducted.Methods: A comprehensive literature search was conducted in multiple databases until 11 January 2018. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using fixed or random effects model.Results: Thirty-eight studies from 17 articles concerning maternal and neonatal GSTM1 and GSTT1 gene polymorphism with LBW risk were included in this meta-analysis, and nine studies from five articles provided data of maternal tobacco exposure status during pregnancy. Maternal GSTM1 null genotype was associated with increased LBW risk (OR = 1.27, 95% CI: 1.12–1.45). There was a nonsignificant but positive association (OR = 1.19, 95% CI: 0.97–1.46) between the maternal GSTT1 null genotype and the LBW risk in the overall analysis. There was a null association between neonatal GSTM1 or GSTT1 polymorphism and LBW risk. There were significant associations between the maternal GSTM1 null and GSTT1 null genotype and LBW risk (for the former, OR = 3.85, 95% CI: 1.68–8.81; for the later, OR = 1.88, 95% CI: 1.01–3.50) in individuals with active smoking, respectively.Conclusion: Maternal GSTM1 and GSTT1 null genotypes, but not neonatal genotypes, are suggested to increase LBW susceptibility, and there are interactions between active smoking and these polymorphisms in the development of LBW.

Glutathione S-Transferase T1 Null Genotype is Associated with Susceptibility to Inflammatory Bowel Disease

Background: The published literature contains conflicting results regarding the impact of the glutathione S-transferase T1 (GSTT1) null genotype on the susceptibility to inflammatory bowel disease. Therefore, we conducted a meta-analysis of observational studies to assess the association. Methods: We searched four online databases for eligible studies. The odds ratio (OR) with 95% CI was used to assess the gene-disease association. We also performed subgroup analyses by type of inflammatory bowel disease and ethnicity. Results: There were 16 individual studies from 11 publications included in the analysis. There were 3366 cases with inflammatory bowel disease and 6013 controls. The meta-analysis of all 16 studies showed the GSTT1 null genotype was associated with increased susceptibility to inflammatory bowel disease (OR = 1.98, 95%CI 1.39-2.84, P < 0.001). The subgroup analysis by ethnicity further identified an association between the GSTT1 null genotype and inflammatory bowel disease in Caucasians, Asians, and Africans. The GSTT1 null genotype was associated with both ulcerative colitis (OR = 1.96, P = 0.004) and Crohn’s disease (OR = 2.01, P = 0.022). The GSTT1 null genotype was still significantly associated with ulcerative colitis (OR = 1.63, P < 0.0001) and Crohn’s disease (OR = 1.40, P = 0.023) after adjusting for study heterogeneity. Conclusion: The GSTT1 null genotype is significantly associated with an increased susceptibility to inflammatory bowel disease and is a risk factor for both ulcerative colitis and Crohn’s disease.

Glutathione S-Transferase T1 (GSTT1) Null Polymorphism, Smoking, and Their Interaction in Coronary Heart Disease: A Comprehensive Meta-Analysis.

The association between glutathione S-transferase T1 (GSTT1) null polymorphism and coronary heart disease (CHD) is inconsistent among studies, and data on the GSTT1 null genotype-smoking interplay in CHD is lacking. We conducted this meta-analysis to investigate the relationship between GSTT1 null polymorphism and CHD and to assess the potential interaction between GSTT1 null genotype and smoking. PubMed and EMBASE databases were searched up to 27 January 2016 using the appropriate terms. Odds ratios were pooled using either fixed-effects or random-effects models. Twenty-nine articles including 31 studies with 15,004 cases and 35,597 controls were eligible. The random-effects model showed that the GSTT1 null genotype was associated with increased CHD risk (OR=1.213, 95%CI: 1.004-1.467; I2=90.4%). After excluding 10 studies detected by Galbraith plot, the fixed effects summary estimate also showed an increased risk of CHD (OR=1.14, 95% CI: 1.06-1.22; I2=27.7%). A case-only analysis including eight studies showed a statistically significant positive interaction between GSTT1 null polymorphism and smoking status on CHD (OR=1.34, 95% CI: 1.09-1.64; I2=0%). Sensitivity analyses further supported the associations. No publication bias was observed. This meta-analysis suggests that GSTT1 null polymorphism is associated with the risk of CHD. To our knowledge, this is the first meta-analysis to prove a positive effect of the interaction between GSTT1 null genotype and smoking status on the risk of CHD. Future studies with detailed individual information are needed to confirm our findings.

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.

The association of GSTT1 deletion polymorphism with lung cancer risk among Chinese population: evidence based on a cumulative meta-analysis.

ObjectivePrevious studies investigating the relationship between glutathione S-transferase T1 (GSTT1) gene deletion polymorphism and lung cancer risk among Chinese population produced inconsistent results. To obtain a precise conclusion, we performed this meta-analysis to evaluate the association between GSTT1 deletion polymorphism and lung cancer risk among Chinese population.MethodsThe databases of Medline/PubMed, Embase, Web of Science, Wanfang Med Online, and Chinese National Knowledge Infrastructure were searched. The strength of the association was assessed by odds ratio (OR) with 95% confidence intervals (95% CI).ResultsOverall, we found an increased lung cancer risk among subjects carrying GSTT1 null genotype compared with those carrying present genotype (OR =1.31, 95% CI: 1.12–1.52) on the basis of 20 studies with 3,351 cases and 4,683 controls. We also observed an increased risk of lung cancer among subjects carrying GSTT1 null genotype compared with those carrying present genotype in stratified analyses (OR =1.31, 95% CI: 1.11–1.55 for healthy subjects-based control; OR =2.29, 95% CI: 1.84–2.85 for squamous cell carcinoma and OR =1.47, 95% CI: 1.22–1.77 for adenocarcinoma, respectively).ConclusionThis meta-analysis suggested that GSTT1 deletion polymorphism might contribute to lung cancer risk among Chinese population.

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.

Evaluation of Glutathione S-transferase T1 (GSTT1) deletion polymorphism on type 2 diabetes mellitus risk in a sample of Yazdian females in Yazd, Iran.

Background:There has been much interest in the role of free radicals and oxidative stress in the pathogenesis of diabetes mellitus (DM). The aim of this study was to assess the possible association between genetic polymorphisms of the glutathione S-transferase-mu (GSTT1) and the risk of the development of DM in a sample of Yazdian females in Yazd, Iran.Methods:This was a case-control study in which GSTT1 polymorphism was genotyped in 51 randomly selected DM patients and 50 randomly selected healthy controls among Yazdian females whose ages ranged from 40 to 70.Results:The frequencies of GSTT1 null genotype and GSTT1 present were 8 and 92%, respectively, in the control samples. In patients with type 2 diabetes (T2DM), the frequencies of GSTT1 null genotype and GSTT1 present were 14 and 86%, respectively. There were higher levels of triglycerides (TG), fasting blood sugar (FBS), total cholesterol (TC), low density lipoprotein (LDL), body mass index (BMI), and high density lipoprotein (HDL) in patients with GSTT1 null genotype than in patients with the GSTT1 present genotype.Conclusions:Our results indicated that the GSTT1 deletion polymorphism is a risk factor for T2DM. We did not determine any significant association between the GSTT1 null genotype and T2DM.

Glutathione S-transferase T1 null genotype and laryngeal cancer risk: a meta-analysis.

Glutathione S-transferase T1 (GSTT1) polymorphic variation has been implicated as a risk factor for various cancers. However, previous studies investigating the association between GSTT1 null genotype and laryngeal cancer risk in Asians reported conflicting outcomes. In the present study, the possible association of laryngeal cancer risk with GSTT1 null genotype was explored by a meta-analysis. Relevant studies were identified through a systemic search of PubMed and Chinese National Knowledge Infrastructure databases. Six studies with a total of 1,824 individuals were included in the meta-analysis. The pooled odds ratio (OR) with 95 % confidence interval (CI) was used to assess the association. Meta-analysis of all included studies showed that there was an obvious association between GSTT1 null genotype and laryngeal cancer risk in Asians (OR = 2.41, 95 % CI 1.27-4.57, P = 0.007, I (2) = 86 %). After adjusting for heterogeneity, there was still an obvious association between GSTT1 null genotype and laryngeal cancer risk in Asians (OR = 1.75, 95 % CI 1.36-2.24, P < 0.001, I (2) = 0 %). The findings from the meta-analysis suggest that GSTT1 null genotype is associated with laryngeal cancer risk in Asians.

Ethnic differences in the association of the glutathione S-transferase T1 (GSTT1) null genotype and risk of gastric carcinoma: a systematic review and meta-analysis

We performed a systematic review and meta-analysis of the association between the glutathione S-transferase T1 (GSTT1) deletion polymorphism and gastric cancer risk in populations from different ethnic backgrounds, based on a comprehensive literature search of the MEDLINE, EMBASE, and COCHRANE libraries. Thirty-six individual case-control studies comprising 7,689 gastric cancer cases and 12,445 controls were included in our meta-analysis. Overall, the GSTT1 null genotype appeared to increase gastric cancer risk (OR 1.17, 95% CI 1.06-1.31, p = 0.003). While Caucasian populations showed an association between the GSTT1 deletion polymorphism and gastric cancer risk (OR 1.27, 95% CI 1.05-1.52, p = 0.01), Asian populations did not show such an association (p = 0.11). When stratified by quality assessment scores, a significant association between the GSTT1 deletion polymorphism and gastric cancer risk was observed only in the Caucasian high quality subgroup (OR 1.27 95% CI 1.01-1.60, p = 0.05). Null genotypes for both GSTT1 and GSTM1 deletion polymorphisms also increased gastric cancer risk (OR 1.37, 95% CI 1.04-1.80, p = 0.03). Our study suggests that the GSTT1 null genotype is associated with a significant increase in gastric cancer risk in Caucasians, but not in Asians. Further well-designed studies are required to confirm the association between GSTT1 polymorphisms and gastric cancer risk in relation to various clinicopathological factors in different ethnic groups, especially Caucasians.

Glutathione S-transferase T1 and myeloperoxidase -463 G>A genotypes in lung cancer patients of Kumaun region.

Background:Null genetic polymorphism of Glutathione S-transferase T1 (GSTT1) and -463 G>A promoter polymorphism of myeloperoxidase (MPO) were studied for association with lung cancer.Materials and Methods:In a case- control study 26 lung cancer patients and 33 healthy individuals from hilly Kumaun region of northern India were investigated. DNA was extracted from peripheral blood. GSTT1 null polymorphism was detected by duplex PCR, and MPO polymorphism was detected by performing PCR-RFLP.Results:An increased but statistically non- significant risk for lung cancer was found for GSTT1 null genotype. No association for MPO -463G>A genotype was evident.Conclusion:Further study with large sample size may reveal such association in this population.

Meta-analysis of the association of glutathione S-transferase T1 null/presence gene polymorphism with the risk of gastric carcinoma

A possible association of glutathione S-transferase T1 (GSTT1) null/presence gene polymorphism and an increased risk of developing gastric carcinoma is still unclear and hotly debated. This investigation was performed to assess the association of the GSTT1 null/presence gene polymorphism with the risk of gastric carcinoma via a meta-analysis to increase sample size and statistical significance. PubMed, Cochrane Library and CBM-disc (China Biological Medicine Database) were searched on March 1, 2013, association reports were identified, and eligible studies were recruited and synthesized. Fifty-two reports were found to be suitable for this meta-analysis for the association of the GSTT1 null genotype with gastric carcinoma risk. The results showed that there was a significantly increased gastric carcinoma risk when the GSTT1 null genotype was present in the overall population (OR 1.21, 95% CI 1.11-1.32, P<0.0001), Caucasians (OR 1.25, 95% CI 1.05-1.48, P=0.01), East-Asians (OR 1.18, 95% CI 1.06-1.31, P=0.003), and Chinese (OR 1.24, 95% CI 1.07-1.44, P=0.005). However, no statistically relevant association could be established for the Indian ethnic group (OR 1.33, 95% CI 0.94-1.90, P=0.11). In conclusion, the GSTT1 null genotype is associated with an increased gastric carcinoma risk in the overall population, Caucasians, East-Asians, and Chinese.

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 glutathione S-transferase T1 null genotype and glioma susceptibility: a meta-analysis

The relationship between genetic polymorphisms of glutathione S-transferase (GST) and the development of glioma has been investigated in several epidemiologic studies. However, these studies report inconsistent results. In order to get this precise result, a meta-analysis was conducted by calculating the pooled odds ratios (OR) and the 95% confidence intervals (95 % CI). Eleven case-control research studies with a total of 2,416 glioma cases and 4,850 controls were included into this meta-analysis. The combined results based on all studies showed that there was no significant association between the GSTT1 null allele and glioma risk (OR = 1.188, 95% CI = 0.929–1.520, P(heterogeneity) = 0.003, P = 0.170). In the subgroup analysis, the same results were found in our work. There was no risk of publication bias in this meta-analysis. Our results suggest that GSTT1 null genotype was not associated with the increased risk of glioma.

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.