Null genotypes of GSTM1 and GSTT1 contribute to risk of cervical neoplasia: an evidence-based meta-analysis

RAP1-GTPase immunostaining is altered in human precancerous and cancerous cervical lesions

Aim: This study investigated RAP1 immunostaining variation in different cell types during CC progression.Methods: Paraffin-embedded cervical tissues from 101 patients were categorized into control, pre-neoplastic and neoplastic groups. RAP1 immunolocalization, HPV detection and genotyping were performed. A semiquantitative immunoreactive score was employed to compare labeling intensity, cellular localization, nuclear labeling, percentage and distribution of reactive cells.Results: 73% (72/99) of cervical specimens were HPV+. RAP1 was localized in the nucleus and cytoplasm of all samples. Cytoplasmic RAP1 immunoscore was higher than nuclear score in all CC groups. RAP1 intensity increased with lesion severity. SCC samples exhibited predominantly intense RAP1 immunostaining.Conclusion: RAP1 is an efficient biomarker for detecting invasive CC lesions but has limited utility in distinguishing SCC grades.

Genetic Polymorphisms in Glutathione S-Transferase (GST) Gene and Their Correlation with Toxicity of Chemotherapy in Breast Cancer Patients

BACKGROUND

Glutathione S-Transferase (GST) is a family of phase II metabolizing enzymes contribute to detoxification and elimination of variety of endogenous as well as exogenous xenobiotics including chemotherapeutic agents. The comprehensive knowledge on the impact of genetic polymorphisms in GST) enzyme coding gene will help to understand the clinical outcomes in breast cancer patients treated with either Adriamycin or paclitaxel or combination of both. In this study we attempted to assess the genetic polymorphisms in GSTM1, GSTT1, GSTP1 and their association with Adriamycin and Paclitaxel induced toxicity reactions in breast cancer patients.

METHODS

Two hundred BC patients receiving Adriamycin and Paclitaxel chemotherapy were enrolled in this study and chemotherapy induced hematological and non-hematological toxicity reactions were noted. The polymorphisms in GSTM1, GSTP1 and GSTT1 gene were studied by PCR and RFLP analysis.

RESULTS

After the univariate analysis of the genetic polymorphisms of GSTM1, GSTP1 and GSTT1 showed that GSTT1 null genotype showed significant association with neutropenia (OR=2.84, 95% CI: 1.06-7.56; p=0.036) in breast cancer patients treated with Adriamycin and GSTT1 null genotype in patients with >1 CINV toxicity confirmed significant correlation (OR=3.75, 95% CI: 1.46-9.59; p=0.005). The genetic polymorphisms of GSTP1 (exon 5) A/G heterozygous genotype was significant in grade >1 toxicity reactions of mucositis (OR=3.22, 95% CI: 1.06-9.71; p=0.037) in breast cancer patients administered with Paclitaxel chemotherapy.

CONCLUSION

The findings obtained from this study proposed significant involvement of GSTT1-null genotype in hematological neutropenia toxicity in response to Adriamycin and GSTM1-null genotype showed negative association with non-hematological toxicity (bodyache) in response to Paclitaxel.

Individual effects of GSTM1 and GSTT1 polymorphisms on cervical or ovarian cancer risk: An updated meta-analysis

Background: Studies have shown that glutathione S-transferase M1 (GSTM1) and. glutathione S-transferase T1 (GSTT1) null genotype may increase the risk of cervical cancer (CC) or ovarian cancer (OC), however, the results of published original studies and meta-analyses are inconsistent. Objectives: To investigate the association between GSTM1 present/null and GSTT1 present/null polymorphisms, with the risk of cervical cancer or ovarian cancer. Methods: The odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the association between GSTM1 present/null and GSTT1 present/null polymorphisms and the risk of cervical cancer or ovarian cancer. To assess the confidence of statistically significant associations, we applied false positive reporting probability (FPRP) and bayesian false discovery probability (BFDP) tests. Results: Overall analysis showed that GSTM1 null was associated with an increased risk of cervical cancer, and subgroup analysis showed a significant increase in cervical cancer risk in Indian and Chinese populations; GSTT1 was not found null genotype are significantly associated with cervical cancer. Overall analysis showed that GSTM1 and GSTT1 null were not associated with the risk of ovarian cancer, subgroup analysis showed that GSTM1 null was associated with an increased risk of OC in East Asia, and GSTT1 null was associated with an increased risk of OC in South America. However, when we used false positive reporting probability and bayesian false discovery probability to verify the confidence of a significant association, all positive results showed "low confidence" (FPRP > .2, BFDP > .8). Conclusion: Overall, this study strongly suggests that all positive results should be interpreted with caution and are likely a result of missing plausibility rather than a true association.

GSTT1 and GSTM1 polymorphisms with human papillomavirus infection in women from southern Brazil: a case-control study

BACKGROUND

Important risk factors for the most common sexually transmitted infection (STI) in the world, human papillomavirus (HPV), include early sexual activity, use of contraceptives, tobacco smoking, and immunological and genetic factors. This study aimed to investigate the relationship between GSTM1 and GSTT1 polymorphisms and HPV infection and associated risk factors in a group of women assisted in the public health system of southwestern Paraná, Brazil.

METHODS AND RESULTS

A case-control study was designed with 21 women with HPV matched by age in the case group and 84 women without the virus in the control group. Viral detection was conducted via polymerase chain reaction (PCR) and GSTM1 and GSTT1 genotyping by Multiplex PCR. The results showed that the GSTT1 null allele was a protective factor against infection (ORadj 0.219; 95% CI 0.078-0.618; p = 0.004). No relationship was observed for the GSTM1 gene. Smoking was defined as a risk factor (ORadj 3.678; 95% CI 1.111-12.171; p = 0.033), increasing the chances of HPV by up to 3.6 times.

CONCLUSION

This study showed, for the first time, the relationship between GSTM1 and GSTT1 genetic polymorphisms and HPV. We found that this relationship protected women from southern Brazil from viral infection, but not from susceptibility.

Lack of association between glutathione S-transferase M1 and T1 gene polymorphisms and susceptibility to preeclampsia: An updated systematic review and meta-analysis

Insufficient response to oxidative stress in placenta is proposed as a contributing factor for preeclampsia (PE) development. Glutathione S-transferases (GST) have significant role in detoxification processes. Conflicting results were published by several research groups regarding GST T1 and GST M1 deletion polymorphism as risk factors for PE. The aim of the present meta-analysis was to get a better understanding of the impact of these polymorphisms in preeclampsia development. To identify relevant case-control studies, the author team searched Clarivate Analytics Web of Science, Scopus, PubMed, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, major subject journals, and gray literature. Pooled odds ratios and 95% confidence intervals for GST M1 and GST T1 deletion polymorphism and preeclampsia were derived from random effects models. This meta-analysis included 10 eligible studies. The pooled analyses showed no association between GST M1/GST T1 deletion polymorphisms and susceptibility to PE. Even though high heterogeneity was founded among results for GST M1 and double null genotypes, Egger's and Begg's tests (0.17 and 0.18, respectively) revealed no statistical evidence of publication bias among included studies. The present updated systematic review and meta-analysis found no association between GST M1 and GST T1 deletion polymorphism and PE risk.

Melatonin: A new inhibitor agent for cervical cancer treatment

Cervical cancer is one of the most common cancers between women and is known as the third leading cause of female cancer related deaths annually. Its detection in early stages allows it to be a preventable and generally treatable disease. Increasing evidence revealed, a variety of internal and external factors are associated with initiation and progression of cervical cancer pathogenesis. Human papilloma virus infection is found as a major cause of cervical cancer. Other molecular and biochemical alterations as well as genetic and epigenetic changes are related cervical cancer progression. Current treatment options often have severe side effects and toxicities thus, new adjuvant agents having synergistic effects and ability to decrease different side effects and toxicities are needed. Melatonin is an indolamine compound secreted from the pineal gland which shows wide range anticancer activities. A large amount of studies indicated inhibitory effects of melatonin against various types of cancers. In addition, experimental evidence reports inhibitory effects of melatonin as an adjuvant therapy on cervical cancer by targeting a sequence of different molecular mechanisms. Herein, for first time, we summarized anticervical cancer effects of melatonin and its underlying molecular mechanisms.

Oxidative stress in cervical cancer pathogenesis and resistance to therapy

Cervical cancer (CC) is one of the most common cancers among females, and it is most notable in developing countries. The exact etiology of CC is poorly understood; but, smoking, oral contraceptives, immunosuppression, and infection with human papillomavirus (HPV) may increase the risk of CC. There is also an association between CC and oxidative stress. Oxidative stress is caused by a disturbed oxidant-antioxidant balance in favor of the former, leading to an excessive generation of free radicals, particularly reactive oxygen species (ROS), and subsequently to biological damages. Thus, redox enzymatic and nonenzymatic regulators are required to maintain the redox homeostasis. Dysregulated antioxidants system and the pathogenic role of oxidative stress in CC have been investigated in several clinical and preclinical studies. In this study, we reviewed studies that have addressed the cross-talk between oxidative stress and CC pathogenesis and resistance to therapy.

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

PROBLEM

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.

METHOD OF STUDY

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.

RESULTS

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).

CONCLUSIONS

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 omega gene polymorphism as a biomarker for human papilloma virus and cervical cancer in Iranian women

Objective

Human papillomavirus (HPV) infection is an important sexually-transmitted infection worldwide. Persistent infections with different high-risk HPV genotypes may cause cervical intraepithelial neoplasia and cervical cancer. Single nucleotide polymorphisms of glutathione S-transferase omega (GSTO) 1 and 2 play an important role in cancer progression. To evaluate GSTO gene polymorphism influence on women’s susceptibility to low-risk or high-risk HPV infections and also risk of cervical cancer development.

Material and Methods

We examined 50 patients with cervical cancer, 43 patients who were positive for HPV, and 43 healthy individuals as negative controls. We used polymerase chain reaction-restriction fragment length polymorphism to determine GSTO1 A140D and GSTO2 N142D variants in study participants.

Results

We found a significant association between the GSTO1 A140D gene polymorphism and HPV 6, 16, 18, 16/18 infections and cervical cancer in Iranian women. We noted a significant difference for the 140AD/142NN combination genotype between patients in the cervical cancer group and healthy controls. There were no significant differences for the GSTO2 N142D genotype and allele frequencies between the patient (i.e., cervical cancer and HPV-positive) groups and controls.

Conclusion

The 140AD genotype, 140D allele, and 140AD/142NN combination genotype seem to confer a protective property in women’s susceptibility to HPV 6, 16, 18, 16/18 infections and cervical cancer. However, the GSTO2 N142D polymorphism is not associated with HPV infections and cervical cancer. It would appear that GSTO1 A140D SNPs likely play a role in the level of susceptibility to HPV-related cervical cancer.

Aging-dependent DNA hypermethylation and gene expression of GSTM1 involved in T cell differentiation

This study investigated whether aging was associated with epigenetic changes of DNA hypermethylation on immune gene expression and lymphocyte differentiation. We screened CG sites of methylation in blood leukocytes from different age populations, picked up genes with age-related increase of CG methylation content more than 15%, and validated immune related genes with CG hypermethylation involved in lymphocyte differentiation in the aged population. We found that 12 genes (EXHX1、 IL-10、 TSP50、 GSTM1、SLC5A5、SPI1、F2R、LMO2、PTPN6、FGFR2、MMP9、MET) were associated with promoter or exon one DNA hypermethylation in the aged group. Two immune related genes, GSTM1 and LMO2, were chosen to validate its aging-related CG hypermethylation in different leukocytes. We are the first to validate that GSTM1_P266 and LMO2_E128 CG methylation contents in T lymphocytes but not polymorphonuclear cells (PMNs) or mononuclear cells (MNCs) were significantly increased in the aged population. The GSTM1 mRNA expression in T lymphocytes but not PMNs or MNCs was inversely associated with the GSTM1 CG hypermethylation levels in the aged population studied. Further studies showed that lower GSTM1 CG methylation content led to the higher GSTM1 mRNA expression in T cells and knockdown of GSTM1 mRNA expression decreased type 1 T helper cell (Th1) differentiation in Jurkat T cells and normal adult CD4 T cells. The GSTM1_P266 hypermethylation in the aged population associated with lower GSTM1 mRNA expression was involved in Th1 differentiation, highlighting that modulation of aging-associated GSTM1 methylation may be able to enhance T helper cell immunity in the elders.

A study of the association of glutathione S-transferase M1/T1 polymorphisms with susceptibility to vitiligo in Egyptian patients

BACKGROUND

The association of glutathione S-transferases M1/T1 (GSTM1/T1) null polymorphisms with vitiligo was proposed in several studies including two Egyptian studies with contradictory results.

OBJECTIVE

The aim here was to assess the association between GSTM1/T1 null polymorphisms and the susceptibility to vitiligo in a larger sample of Egyptian patients with generalized vitiligo.

METHODS

This study included 122 vitiligo patients and 200 healthy controls that were age, and gender matched. Assessment of GSTM1/T1 gene polymorphisms was done using a multiplex polymerase chain reaction (PCR).

RESULTS

Increased odds of generalized vitiligo was observed with the null genotypes of GSTM1 and GSTT1 polymorphisms (P<0.05). Controls with GSTM1 null/GSTT1+ heterozygosis presented with a 2.97 odds protection from having generalized vitiligo (OR=2.97, 95%CI=1.1-7.7) (P=0.02) compared with patients.

STUDY LIMITATIONS

Small sample size of patients.

CONCLUSIONS

This study showed a significant trend towards an association with the combination of the GSTM1/GSTT1 double null polymorphism and generalized vitiligo. Individuals with GSTM1 null/GSTT1+ heterozygosis have a 2.97 odds protection from having generalized vitiligo compared with patients. It was is the first time, to our knowledge, that such an association has been reported.

Association between genetic polymorphisms in the promoters of let-7 and risk of cervical squamous cell carcinoma

Numerous reports showed low levels of let-7 family in cervical cancer, acting as tumor suppressors by regulating multiple target genes. Genetic variants in the promoter of miRNA have been reported to influence individuals' susceptibility to human diseases. We aimed to investigate the association of rs10877887 and rs13293512 polymorphisms in the promoters of let-7 with risk of cervical squamous cell carcinoma (CSCC). A total of 331 patients with CSCC and 358 controls were included. Genotyping of rs10877887 was done using polymerase chain reaction-restriction fragment length polymorphism analysis. Genotyping of rs13293512 was performed using Taqman allelic discrimination. Relative expression of let-7 family was determined using quantitative real-time polymerase chain reaction. The rs10877887CC genotype was significantly associated with an increased risk of CSCC compared with the rs10877887TT (adjusted OR=2.11, 95% CI, 1.31-3.40, p-value=0.002) or rs10877887 TT/CT genotypes (adjusted OR=2.11, 95% CI, 1.34-3.31, p-value<0.001). Similarly increased risk of CSCC was observed when compared rs10877887T with rs10877887C allele (adjusted OR=1.35, 95% CI, 1.08-1.69, p-value=0.008). Combined analysis showed that individuals carrying the genotypes of rs10877887CC+rs13293512CC had a 4.78-fold higher risk to develop CSCC compared with those carrying the genotypes of rs10877887CT/TT+rs13293512CT/TT (OR=4.78, 95% CI, 1.78-12.84, p-value=0.001). Additionally, patients harboring rs10877887CC genotype had a lower level of let-7i in CSCC tissues (p-value=0.02). This observation indicates that rs10877887 may be a useful biomarker for the etiology of CSCC.

Influence of chemotherapeutic drug-related gene polymorphisms on toxicity and survival of early breast cancer patients receiving adjuvant chemotherapy

BACKGROUND

We investigated whether GSTT1 ("null" allele), GSTM1 ("null"allele), GSTP1 (A313G), RFC1 (G80A), MTHFR (C677T), TS (2R/3R) polymorphisms were associated with toxicity and survival in patients with early breast cancer (EBC) treated with adjuvant chemotherapy (CT).

METHODS

This prospective trial included patients with stage I-III BC subjected to CT with CMF or FEC regimens. PCR-RFLP was performed for MTHFR, RFC1 and GSTP1, while PCR for TS, GSTT1 and GSTM1 genes.

RESULTS

Among the 244 patients consecutively enrolled, 48.7% were treated with FEC and 51.3% with CMF. Patients with TS2R/3R genotype showed less frequently severe neutropenia (G3/G4) than those with TS2R/2R and 3R/3R genotype (p = 0.038). Patients with MTHFRCT genotype had a higher probability of developing severe neutropenia than those with MTHFR CC genotype (p = 0.043). Patients with RFC1GG or GSTT1-null genotype or their combination (GSTT1-null/RFC1GG) were significantly associated with a shorter disease free survival (DFS) (p = 0.009, p = 0.053, p = 0.003, respectively) and overall survival (OS) (p = 0.036, p = 0.015, p = 0.005, respectively). Multivariate analysis confirmed the association of RFC1GG genotype with a shorter DFS (p = 0.018) and of GSTT1-null genotype of a worse OS (p = 0.003), as well as for the combined genotypes GSTT1-null/RFC1GG, (DFS: p = 0.004 and OS: p = 0.003).

CONCLUSIONS

Our data suggest that TS2R/2R and 3R/3R or MTHFR CT genotypes have a potential role in identifying patients with greater risk of toxicity to CMF/FEC and that RFC1 GG and GSTT1-null genotypes alone or in combination could be important markers in predicting clinical outcome in EBC patients.

Genetic polymorphisms of glutathione S transferase and cervical intraepithelial neoplasia

Aim: The present study aim to analyze the relationship between GST M/T genotypes of glutathione S-transferases and cervical intraepithelial neoplasia.

Materials and Methods: A prospective case-control study has been designed including 69 cases with different degrees of cervical dysplasia and 107 controls. All patients had been examined colposcopically. For every patient both cervical and blood specimen have been obtained. The peripheral blood was used for GST M/T genotyping. The statistical analysis was performed using OR and chi-square at a level of significance inferior to 0.05.

Results: No statistically significant differences had been found between cases and controls for GST T-/M- geno-type (T-/M-, χ2=0.03, p= 0.8610) and T+/M+ χ2=0.65, p = 0.4197. Patients with in situ carcinoma had significant GST genotype association for T-/M+ genotype (OR=4.66, CI 95% [0.6528,24.9725], χ2=4.6, p=0.0314) and for T+/M- genotype (OR=0.12, CI 95% [0.0027,0.9465], χ2=0.05, p=0.0219).

Conclusion: The combination of GST genotypes can be included in a predictive score for patients with cervical carcinoma.

Effect of ATM-111 (G>A) Polymorphism on Cancer Risk: A Meta-Analysis

OBJECTIVE

To assess the relationship between the ataxia telangiectasia mutated (ATM) gene-111 (G>A) polymorphism and cancer risk.

METHODS

The PubMed, EMBASE, Web of Science, and China National Knowledge Infrastructure databases were searched comprehensively. A total of 16 case-control studies with 12,273 cases and 13,046 controls were included in this meta-analysis; 12 of them were from the Chinese population. Five studies assessed smoking effects, including 3038 smokers and 1003 nonsmokers. Odds ratio (OR) was determined by using a genetic model-free approach. Heterogeneity was quantified by I(2) statistics. Publication bias was also evaluated.

RESULTS

The recessive model (AA vs. AG + GG) was suggested as the most appropriate genetic model. After elimination of heterogeneity, it was found that the ATM-111 (G>A) AA genotype is significantly associated with increased susceptibility to overall cancer risk in a fixed effects model (OR = 1.09; 95% CI = 1.03-1.15; p < 0.01; I(2) < 0.01). In the subgroup analysis, the result of pooled analyses among the Chinese population revealed similar associations (OR = 1.12; 95% CI = 1.04-1.22; p < 0.01; I(2) < 0.01). As for specific cancer analysis, an increase was correlated with lung cancer risk (OR = 1.12; 95% CI = 1.01-1.24; p = 0.03) and breast cancer risk (OR = 1.08; 95% CI = 1.00-1.16; p = 0.05). In addition, a stronger association was found among nonsmokers (OR = 1.31; 95% CI = 1.13-1.52; p < 0.01).

CONCLUSION

This meta-analysis suggests that AA genotype of the ATM-111 gene (G>A) may be a risk factor for breast cancer and lung cancer, especially among nonsmokers, within the Chinese population.

Association of the p53 or GSTM1 polymorphism with the risk of nasopharyngeal carcinoma: A meta-analysis

p53 and glutathione S-transferase M1 (GSTM1) are the most popular suppressor genes. Several previous studies demonstrated positive associations of these gene polymorphisms with numerous cancer types, including hepatocellular cancer, while the association between p53/GSTM1 polymorphisms and the nasopharyngeal carcinoma (NPC) risk was inconsistent and underpowered. However, no studies investigating the combinational effect of these two genes on NPC risk were performed. To confirm the effects of p53 and GSTM1 polymorphisms on the risk of NPC, a meta-analysis of all the available previous studies associating p53 and GSTM1 with the risk of NPC was performed. A comprehensive search of PubMed, Web of Science and SD database until November 2014 was performed to identify the relevant studies. The data were extracted by two independent authors and pooled odds ratio (OR) with 95% confidence interval (CI) was calculated. Meta-regression and subgroup analyses were performed to identify the source of heterogeneity. Finally, five studies with 1,419 cases and 1,707 controls were included for the p53 polymorphism and three studies with 837 cases and 1,299 controls were included for the GSTM1 polymorphism. Regarding p53, a significantly increased NPC risk was observed in the overall population (C vs. G, OR, 1.245; 95% CI, 1.045-1.483; P=0.014; additive models: CC vs. GG, OR, 1.579; 95% CI, 1.100-2.265; P=0.013 and CG vs. GG, OR, 1.230; 95% CI, 1.039-1.456; P=0.016; dominant model, OR, 1.321; 95% CI, 1.127-1.549; P=0.001; recessive model, OR, 1.429; 95% CI, 1.017-2.009; P=0.040). Concerning GSTM1, a significantly increased NPC risk was observed in the overall population (null versus non-null, OR, 1.282; 95% CI, 1.075-1.530; P=0.006). In the subgroup analyses stratified by the source of controls, a significant association of p53 with NPC risk was also demonstrated, while no association with GSTM1 was observed. Therefore, the p53 G72C polymorphism may have a susceptible role in the carcinogenesis of NPC, while genetic deletion of GSTM1 may contribute to increased susceptibility to NPC. Further large and well-designed studies are required to confirm this association.

Prevalence of Null Genotypes of Glutathione S-Transferase T1 (GSTT1) and M1 (GSTM1) in Seven Iranian Populations

BACKGROUND

Previous studies have revealed significant differences between populations for genotypic frequencies of glutathione S-transferase T1 (GSTT1) and M1 (GSTM1) polymorphisms. In order to find the frequency of the null genotypes of GSTM1 and GSTT1 in Iranian populations, the present study was carried out.

METHODS

The total study subjects consisted of 1340 unrelated healthy Muslims/Iranian. From these 297, 200, 123, 168, 152, 200, and 200 individuals from Tabriz (East Azerbaijan Province; belong to Azaris), Yasuj (Kohgiluyeh-va-Boyerahmad Province; belong to Lurs), Abarku (Yazd Province; belong to Persians), Zahedan (Sistan-va-Balouchestan Province; belong to Balouchis), Zahedan (Sistan-va-Balouchestan Province; belong to Sistanis), Kermanshah (Kermanshah Province; belong to Kurds), and Gorgan (Golestan Province; belong to Turkmen) respectively. The genotypes were detected by multiplex PCR.

RESULTS

The frequency of GSTM1 null genotype among Azaris, Lurs, Persians, Balouchis, Sistanis, Kurds, and Turkmen was 43.8, 50.0, 52.0, 50.0, 51.3, 56.0, and 53.0%, respectively. There was no significant difference between these populations for the genotypic distribution of the GSTM1 polymorphism (χ(2)=8.47, df=6, P=0.206). The frequency of GSTT1 null genotype among Azaris, Lurs, Persians, Balouchis, Sistanis, Kurds, and Turkmen was 18.2, 17.0, 29.3, 20.8, 17.8, 18.5, and 23.0%, respectively. There was very similarity between Azaris, Kurds and Lurs for the frequency of GSTT1 genotypes (χ(2)=0.17, df=2, P=0.916).

CONCLUSION

By comparing the frequency of GSTT1 genotypes among Iranian populations, Caucasians and Asians, it is concluded that Azaris, Kurds and Lurs were similar to each other. Taken together, it is suggested that although Azaris are Turkish speaking belong to Caucasians.

Functional Connectivity Disruption in Neonates with Prenatal Marijuana Exposure

Prenatal marijuana exposure (PME) is linked to neurobehavioral and cognitive impairments; however, findings in childhood and adolescence are inconsistent. Type-1 cannabinoid receptors (CB1R) modulate fetal neurodevelopment, mediating PME effects on growth of functional circuitry sub-serving behaviors critical for academic and social success. The purpose of this study was to investigate the effects of prenatal marijuana on development of early brain functional circuitry prior to prolonged postnatal environmental influences. We measured resting state functional connectivity during unsedated sleep in infants at 2–6 weeks (+MJ: 20 with PME in combination with nicotine, alcohol, opiates, and/or selective serotonin reuptake inhibitors; −MJ: 23 exposed to the same other drugs without marijuana, CTR: 20 drug-free controls). Connectivity of subcortical seed regions with high fetal CB1R expression was examined. Marijuana-specific differences were observed in insula and three striatal connections: anterior insula–cerebellum, right caudate–cerebellum, right caudate–right fusiform gyrus/inferior occipital, left caudate–cerebellum. +MJ neonates had hypo-connectivity in all clusters compared with −MJ and CTR groups. Altered striatal connectivity to areas involved in visual spatial and motor learning, attention, and in fine-tuning of motor outputs involved in movement and language production may contribute to neurobehavioral deficits reported in this at-risk group. Disrupted anterior insula connectivity may contribute to altered integration of interoceptive signals with salience estimates, motivation, decision-making, and later drug use. Compared with CTRs, both +MJ and −MJ groups demonstrated hyper-connectivity of left amygdala seed with orbital frontal cortex and hypo-connectivity of posterior thalamus seed with hippocampus, suggesting vulnerability to multiple drugs in these circuits.

A Functional Polymorphism in the Promoter of MiR-143/145 Is Associated With the Risk of Cervical Squamous Cell Carcinoma in Chinese Women: A Case-Control Study

MiR-143/145 is down-regulated in cervical cancer, which may serve as a tumor suppressor by targeting KRAS and Ras-responsive element-binding protein (RREB1). Activated KRAS leads to down-regulation of miR-143/145 transcription in a RREB1-dependent manner, establishing a miR-143/145-KRAS-RREB1 feedback loop. A polymorphism rs4705343C/T in the promoter of miR-143/145 might influence the binding of TATA-binding protein. We hypothesized that the miR-143/145 rs4705343 and KRAS rs712 may be related to the occurrence of cervical squamous cell carcinoma (CSCC). In this study, we genotyped the 2 polymorphisms in 415 patients with CSCC and 504 controls using polymerase chain reaction-restriction fragment length polymorphism. The promoter activities were measured by the Dual-Luciferase Reporter Assay System. We found that the rs4705343TC genotype was associated with an increased risk of CSCC (adjusted odds ratio [OR] = 1.37; 95% confidence interval [CI], 1.05-1.80). The significantly increased association was also observed in a dominant genetic model (adjusted OR = 1.32; 95% CI, 1.01-1.72). Combined analysis showed that individuals carrying the genotypes of rs4705343 TC/CC and rs712GT/TT had a 1.47-fold increased risk of CSCC (adjusted OR = 1.47; 95% CI, 1.01-2.15). By using multifactor dimensionality reduction software method, we identified a significant interaction between the miR-143/145 rs4705343 and KRAS rs712. Dual-Luciferase Reporter Assay showed that the luciferase activity was significantly lower in cells transfected with the rs4705343C allele than that of the rs4705343T allele. These findings indicate that miR-143/145 rs4705343 and KRAS rs712 may contribute to the etiology of CSCC in Chinese women.

Lack of participation of the GSTM1 polymorphism in cervical cancer development in Northeast Thailand

The potential association between the GSTM1 deletion polymorphism and risk of cervical cancer was investigated in Northeastern Thailand. DNA was extracted from buffy coat specimens of 198 patients with squamous cell carcinoma of the cervix and 198 age-matched healthy controls. Genotyping of the GSTM1 was conducted by using two PCR methods, a short- and a long-PCR. Distribution of the GSTM1 genotypes in between the cases and the controls was not significantly different (p>0.5 by χ2 test). The results suggest that the GSTM1 deletion polymorphism is not a risk factor for squamous cell carcinoma of the cervix in the northeast Thai women.

Angiotensin-converting enzyme insertion/deletion polymorphism and gastric cancer: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Several studies were launched to investigate the potential function of ACE I/D polymorphism in gastric cancer development and prognosis, but no conclusive results have been obtained. We conducted a systematic review and meta-analysis to evaluate the association between ACE I/D polymorphism and gastric cancer.

METHODS

A systemic search was performed in PubMed, Embase, China National Knowledge Infrastructure (CNKI), Wanfang and Weipu databases (until October 15,2013) to identify all published records on association between the ACE I/D polymorphism and gastric cancer. We adopted the odds ratio (OR) and 95% confidence interval (95%CI) as measure of effect. Meta-analysis was conducted using fixed/random-effects model in STATA 12.0.

RESULTS

Eventually a total of seven studies with 1392 cases and 2951 controls were included in our meta-analysis. No association was detected between ACE I/D polymorphism and gastric cancer susceptibility (DI+DD vs II: OR=1.06, 95%CI=0.92-1.21, P=0.443). However, we found that the DD genotype was significantly associated with increased lymph node metastasis (DD vs DI+II: OR=3.48, CI=1.77-6.85, P<0.001), and more advanced clinical stage (DD vs DI+II: OR=2.43, CI=1.34-4.39, P=0.003) of gastric cancer.

CONCLUSION

Our results indicated that ACE I/D polymorphism could not be directly associated with gastric cancer susceptibility, but might play important role in gastric cancer prognosis. Future studies with larger sample size are warranted for further evaluation.

An Updated Meta-Analysis: Risk Conferred by Glutathione S-Transferases (GSTM1 and GSTT1) Polymorphisms to Age-Related Cataract

Purpose. To study the effects of glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) polymorphisms on age-related cataract (ARC). Methods. After a systematic literature search, all relevant studies evaluating the association between GSTs polymorphisms and ARC were included. Results. Fifteen studies on GSTM1 and nine studies on GSTT1 were included in this meta-analysis. In the pooled analysis, a significant association between null genotype of GSTT1 and ARC was found (OR = 1.229, 95% CI = 1.057–1.429, and P = 0.007). In subgroup analysis, the association between cortical cataract (CC) and GSTM1 null genotype was statistically significant (OR = 0.713, 95% CI = 0.598–0.850, and P < 0.001). In addition, GSTM1 null genotype was significantly associated with ARC causing risk to individuals working indoors and not individuals working outdoors. The association between GSTT1 null genotype and risk of ARC was statistically significant in Asians (OR = 1.442, 95% CI = 1.137–1.830, and P = 0.003) but not in Caucasians. Conclusions. GSTM1 positive genotype is associated with increased risk of CC and loses the protective role in persons who work outdoors. Considering the ethnic variation, GSTT1 null genotype is found to be associated with increased risk of ARC in Asians but not in Caucasians.

Functional variants in CYP1A1 and GSTM1 are associated with clearance of cervical HPV infection

OBJECTIVE

We evaluated time to clearance of high risk (HR) HPV infection in relation to functional variants in three genes (CYP1A1, GSTT1, and GSTM1).

METHODS

The study group consisted of 450 HR-HPV infected women from the Atypical squamous cells of undetermined significance-low-grade squamous intraepithelial Lesion Triage Study (ALTS) cohort followed up at the clinical center at Birmingham, Alabama. The Cox proportional hazard model with the Wei-Lin-Weisfeld (WLW) approach was used, controlling for relevant covariates.

RESULTS

Women who were polymorphic for CYP1A1 experienced an HR-HPV clearance rate that was 20% (HR=0.80, p=0.04) lower than women without the polymorphism for CYP1A1, adjusting for all other cofactors. The GSTM1 null genotype was associated with higher HR-HPV clearance rate (HR=1.39, p=0.006). The polymorphism in GSTT1 was not significantly associated with time to clearance of HR-HPV.

CONCLUSIONS

Xenobiotic metabolism genes may influence the natural history of HR-HPV infection and its progression to cervical cancer.

XRCC1 gene polymorphisms and glioma risk in Chinese population: a meta-analysis

Background

Three extensively investigated polymorphisms (Arg399Gln, Arg194Trp, and Arg280His) in the X-ray repair cross-complementing group 1 (XRCC1) gene have been implicated in risk for glioma. However, the results from different studies remain inconsistent. To clarify these conflicts, we performed a quantitative synthesis of the evidence to elucidate these associations in the Chinese population.

Methods

Data were extracted from PubMed and EMBASE, with the last search up to August 21, 2014. Meta-analysis was performed by critically reviewing 8 studies for Arg399Gln (3062 cases and 3362 controls), 8 studies for Arg194Trp (3419 cases and 3680 controls), and 5 studies for Arg280His (2234 cases and 2380 controls). All of the statistical analyses were performed using the software program, STATA (version 11.0).

Results

Our analysis suggested that both Arg399Gln and Arg194Trp polymorphisms were significantly associated with increased risk of glioma (for Arg399Gln polymorphism: Gln/Gln vs. Arg/Arg, OR = 1.82, 95% CI = 1.46–2.27, P = 0.000; Arg/Gln vs. Arg/Arg, OR = 1.25, 95% CI = 1.10–1.42, P = 0.001 and for Arg194Trp polymorphism: recessive model, OR = 1.78, 95% CI = 1.44–2.19, P = 0.000), whereas the Arg280His polymorphism had no influence on the susceptibility to glioma in a Chinese population.

Conclusions

This meta-analysis suggests that there may be no association between the Arg280His polymorphism and glioma risk, whereas the Arg399Gln/Arg194Trp polymorphisms may contribute to genetic susceptibility to glioma in the Chinese population. Nevertheless, large-scale, well-designed and population-based studies are needed to further evaluate gene-gene and gene–environment interactions, as well as to measure the combined effects of these XRCC1 variants on glioma risk.

Association of DCC, MLH1, GSTT1, GSTM1, and TP53 gene polymorphisms with colorectal cancer in Kazakhstan

This study presents the first results of a molecular-genetic study of colorectal cancer (CRC) in Kazakhstan. Blood samples were collected from patients diagnosed with rectal or colon cancer (249 individuals) as well as a control cohort of healthy volunteers (245 individuals), taking into account the age, gender, ethnicity, and smoking habits of the CRC patients. Combined analysis of data obtained from individuals of either Kazakh or Russian decent showed a significant association with increased CRC risk in the following genotypes: DCC (32008376G/G and G/A versus A/A; OR = 3.45, 95 % confidence interval (95 %CI) = 1.75-6.81, χ (2) = 14.07, p < 0.0002), MLH1 (-93G/G versus G/A and A/A; OR = 1.45, 95 %CI = 1.02-2.07, χ (2) = 4.21, p < 0.04), TP53 (Pro72Pro; OR = 3.80, 95 %CI = 2.46-5.88, χ (2) = 61.27, p < 0.0001), combination GSTT1 deletions with heterozygotes versus normal homozygotes (OR = 1.43, 95 %CI = 1.00-2.04, χ (2) = 3.90, p < 0.05), and GSTM1 deletions (OR = 1.83, 95 %CI = 1.28-2.63, χ (2) = 11.04, p < .001). Analysis for ethnicity and smoking for each of the investigated polymorphisms showed that some genotypes can have a predictive value for susceptibility to CRC, at least those that demonstrate statistically significant ORs either for the combined mixed population of Kazakhstan or for both main ethnic groups separately (Kazakhs and Russians): TP53 Pro72Pro homozygous (for Kazakh-OR = 3.40, 95 %CI = 1.63-7.06, χ (2) = 11.35, p < 0.003; for Russian-OR = 4.69, 95 %CI = 2.53-8.66, χ (2) = 53.19, p < 0.0001) and GSTM1 deletions (for Kazakh-OR = 2.30, 95 %CI = 1.21-4.40, χ (2) = 8.42, p < 0.01; for Russian-OR = 1.64, 95 %CI = 1.01-2.66, χ (2) = 7.82, p < 0.02).

Cytoprotective and regulatory functions of glutathione S-transferases in cancer cell proliferation and cell death

PURPOSE

Glutathione S-transferases (GSTs) family of enzymes is best known for their cytoprotective role and their involvement in the development of anticancer drug resistance. Recently, emergence of non-detoxifying properties of GSTs has provided them with significant biological importance. Addressing the complex interactions of GSTs with regulatory kinases will help in understanding its precise role in tumor pathophysiology and in designing GST-centered anticancer strategies.

METHODS

We reviewed all published literature addressing the detoxification and regulatory roles of GSTs in the altered biology of cancer and evaluating novel agents targeting GSTs for cancer therapy.

RESULTS

The role of GSTs, especially glutathione S-transferase P1 isoform in tumoral drug resistance, has been the cause of intense debate. GSTs have been demonstrated to interact with different protein partners and modulate signaling pathways that control cell proliferation, differentiation and apoptosis. These specific functions of GSTs could lead to the development of new therapeutic approaches and to the identification of some interesting candidates for preclinical and clinical development. This review focuses on the crucial role played by GSTs in the development of resistance to anticancer agents and the major findings regarding the different modes of action of GSTs to regulate cell signaling.

Glutathione S-transferase T1 and M1 polymorphisms and risk of uterine cervical lesions in women from central Serbia

The aim of this study was to investigate the frequencies of GSTT1 and GSTM1 deletion polymorphisms in newly-diagnosed patients with uterine cervical lesions from central Serbia. Polymorphisms of GST genes were genotyped in 97 patients with cervical lesions and 50 healthy women using a multiplex polymerase chain reaction (PCR). The GSTM1 null genotype was significantly more prominent among the patients than in controls (74.2% vs 56.0%), the risk associated with lesions being almost 2.3-fold increased (OR=2.26, 95%CI=1.10-4.65, p=0.03) and 3.17-fold higher in patients above >45 years old (95%CI=1.02-9.79, p=0.04). The analysis of the two genotypes demonstrated that GSTM1 null genotype significantly increased risk only for low grade squamous intraepithelial lesion-LSIL (OR=2.81, 95%CI=1.03-7.68, p=0.04). GSTT1 null genotype or different genotype combinations were not found to be risk factors, irrespective to lesion stages, age or smoking. We found that the risk of cervical lesions might be significantly related to the GSTM1 null genotype, especially in women aged above 45 years. Furthermore, the GSTM1 polymorphism might have greater role in development of early stage lesions.

Oxidative stress and mitochondrial dysfunction across broad-ranging pathologies: toward mitochondria-targeted clinical strategies

Beyond the disorders recognized as mitochondrial diseases, abnormalities in function and/or ultrastructure of mitochondria have been reported in several unrelated pathologies. These encompass ageing, malformations, and a number of genetic or acquired diseases, as diabetes and cardiologic, haematologic, organ-specific (e.g., eye or liver), neurologic and psychiatric, autoimmune, and dermatologic disorders. The mechanistic grounds for mitochondrial dysfunction (MDF) along with the occurrence of oxidative stress (OS) have been investigated within the pathogenesis of individual disorders or in groups of interrelated disorders. We attempt to review broad-ranging pathologies that involve mitochondrial-specific deficiencies or rely on cytosol-derived prooxidant states or on autoimmune-induced mitochondrial damage. The established knowledge in these subjects warrants studies aimed at elucidating several open questions that are highlighted in the present review. The relevance of OS and MDF in different pathologies may establish the grounds for chemoprevention trials aimed at compensating OS/MDF by means of antioxidants and mitochondrial nutrients.

GSTM1 and GSTT1 null polymorphisms and childhood acute leukemia risk: evidence from 26 case-control studies

Several molecular epidemiological studies have been conducted to examine the association between glutathione S-transferase mu-1 (GSTM1) and glutathione S-transferase theta-1 (GSTT1) null polymorphisms and childhood acute leukemia; however, the conclusions remain controversial. We performed an extensive meta-analysis on 26 published case-control studies with a total of 3252 cases and 5024 controls. Crude odds ratios (ORs) with 95% confidence interval were used to assess the strength of association between childhood acute leukemia risk and polymorphisms of GSTM1 and GSTT1. With respect to GSTM1 polymorphism, significantly increased risk of childhood acute leukemia was observed in the overall analysis (OR = 1.30; 95%CI, 1.11-1.51). Furthermore, a stratification analysis showed that the risk of GSTM1 polymorphism are associated with childhood acute leukemia in group of Asians (OR = 1.94; 95%CI, 1.53-2.46), Blacks (OR = 1.76; 95%CI, 1.07-2.91), ALL (OR = 1.33; 95%CI, 1.13-1.58), '< 100 cases and <100 controls' (OR = 1.79; 95%CI, 1.21-2.64), '≥ 100 cases and ≥ 100 controls' (OR = 1.25; 95%CI, 1.02-1.52), and population-based control source (OR = 1.40; 95%CI, 1.15-1.69). With respect to GSTT1 polymorphism, significant association with childhood acute leukemia risk was only found in subgroup of Asian. This meta-analysis supports that GSTM1 null polymorphism is capable of causing childhood acute leukemia susceptibility.

GSTT1 and GSTM1 polymorphisms and prostate cancer risk in Asians: a systematic review and meta-analysis

Glutathione S-transferases (GSTs) enzymes are involved in conjugation of electrophilic compounds to glutathione, and glutathione S-transferase T 1 (GSTT1) and glutathione S-transferase M 1 (GSTM1) polymorphisms have been implicated as risk factors for prostate cancer. We conducted a systematic review and meta-analysis to define the effect of GSTM1 and GSTT1 null genotypes on prostate cancer risk in Asians. We searched the PubMed and Wanfang Medical databases to identify published case-control studies investigating the associations of GSTM1 and GSTT1 null genotypes with risk of prostate cancer in Asians. Heterogeneity was assessed using Cochran's Q statistic and odds ratios (OR) with corresponding 95 % confidence intervals (95 % CI) from individual studies were pooled using fixed or random effects models according to the heterogeneity. There were 18 studies (2,046 cases, 2,876 controls) on GSTM1 polymorphism, 15 studies (1,677 cases, 2,431 controls) on GSTT1 polymorphism, and 6 studies (675 cases, 853 controls) on GSTM1/GSTT1 interaction analysis. Overall, GSTM1 null genotype was significantly associated with increased risk of prostate cancer in Asians (random effects OR 1.80, 95 % CI 1.48-2.18, P < 0.001), and GSTT1 null genotype was also significantly associated with increased risk of prostate cancer in Asians (random effects OR 1.40, 95 % CI 1.10-1.80, P < 0.001). In addition, the GSTM1/GSTT dual null genotype was associated with higher risk of prostate cancer in Asians (random effects OR 2.14, 95 % CI 1.59-2.89, P = 0.007). In conclusion, GSTM1 and GSTT1 null genotypes are associated with increased risk of prostate cancer in Asians, and GSTM1 and GSTT1 null genotypes are risk factors for the development of prostate cancer.

Glutathione S-transferase polymorphisms (GSTM1, GSTT1 and GSTP1) and their susceptibility to renal cell carcinoma: an evidence-based meta-analysis

Background

The association of the three Glutathione S-transferases (GSTs) polymorphisms (GSTM1, GSTT1 and GSTP1) genotypes with their individual susceptibilities to renal cell carcinoma (RCC) has not been well established. We performed a quantitative meta-analysis to assess the possible associations between the GSTM1, GSTT1 and GSTP1 genotypes and their individual susceptibilities to renal cell carcinoma.

Methods

We systematically searched the PubMed, CNKI and Embase databases to identify the relevant studies. Finally, 11 eligible studies were selected. The pooled odds ratios (ORs) with their 95% confidence intervals (CIs) were used to assess the association between the GSTs polymorphisms and the risk of RCC. Multiple subgroup analyses and quality assessment of the included studies were performed based on the available information.

Results

None of the GSTs polymorphisms had a significant association with the RCC risk. Similar results were found in the subgroup analyses, except for the GSTs polymorphisms in the situations described below. The GSTM1 and GSTT1 active genotypes in subjects exposed to pesticides (GSTM1: OR = 3.44; 95% CI, 2.04–5.80; GSTT1: OR = 2.84; 95% CI, 1.75–4.60), most of the GSTs genotypes in Asian populations (GSTT1: OR = 2.39, 95% CI = 1.63–3.51; GSTP1: Dominant model: OR = 1.50, 95% CI = 1.14–1.99; Additive model: OR = 1.39, 95% CI = 1.12–1.73; AG vs. AA: OR = 1.47, 95% CI = 1.10–1.97; GG vs. AA: OR = 1.82, 95% CI = 1.07–3.09) and the dual null genotype of GSTT1-GSTP1 (OR = 2.84, 95% CI = 1.75–4.60) showed positive associations with the RCC risk.

Conclusion

Our present study provides evidence that the GSTM1, GSTT1 and GSTP1 polymorphisms are not associated with the development of RCC. However, more case-control studies are needed for further confirmation.

The determination of genetic markers of age-related cancer pathologies in populations from Kazakhstan

Aging associates with a variety of pathological conditions such as cancer, cardiovascular, neurodegenerative, autoimmune diseases, and metabolic disorders. The oncogenic alterations overlap frequently with the genes linked to aging. Here, we show that several aging related genes may serve as the genetic risk factors for cervical and esophagus cancers. In our study, we analyzed samples obtained from 115 patients with esophageal and 207 patients with cervical cancer. The control groups were selected to match the ethnicity and age of cancer patients. We examined the genes involved in the processes of xenobiotics detoxification (GSTM1 and GSTT1), DNA repair (XRCC1 and XRCC3), and cell cycle regulation and apoptosis (CCND1 and TP53). Our study revealed that deletions of GSTT1 and GSTM1 genes or the distinct point mutations of XRCC1 gene are associated with cervical and esophageal cancers. These results will lead to development of screening for detection of individuals susceptible to esophageal and cervical cancers. Introduction of the screening programs will allow the early and effective preventive measures that will reduce cancer incidence and mortality in Kazakhstan.

Defective antioxidant systems in cervical cancer

Cervical cancer remains a great problem for woman health, as it is the second deadly cancer of females worldwide. The infection of human papilloma virus (HPV) is the major risk factor for this cancer, although several other factors are also associated. Oxidative stress or antioxidant deficiency has been frequently identified to be associated with cervical cancer. Defects in the antioxidant enzyme systems are reported to play important role behind this antioxidant deficiency, which is responsible for the production of reactive oxygen species and ultimately, DNA damage in cervical cells. In response, cells become more vulnerable to HPV infection for cervical cancer development. Recently, antioxidant therapies or dietary supplementation of antioxidants have gained considerable interests in the cervical cancer treatment. In this study, we have reviewed the association of defective antioxidant systems and cervical cancer development. The recent advances in both of the basic and clinical research focusing on possible antioxidant therapy have also been discussed.

Effect of GSTM1-Polymorphism on Disease Progression and Oxidative Stress in HIV Infection: Modulation by HIV/HCV Co-Infection and Alcohol Consumption

Objective

To examine the effects of GSTM1 null-allele polymorphism on oxidative stress and disease progression in HIV infected and HIV/hepatitis C (HCV) co-infected adults.

Methods

HIV-infected and HIV/HCV co-infected participants aged 40–60 years old with CD4 cell count >350 cells/ µl, were recruited. GSTM1 genotype was determined by quantitative PCR. Oxidative stress (mitochondrial 8-oxo-2’-deoxyguanosine [8-oxo-dG], malondialdehyde [MDA], oxidized glutathione and Complexes I and IV), apoptosis and HIV disease (CD4 count and viral load) markers were measured. Gene copies were not quantified, thus the Hardy-Weinberg formula was not applicable.

Results

Of the 129 HIV-infected participants, 58 were HIV/HCV co-infected. GSTM1 occurred in 66% (62/94) in those of African descent, and 33% (11/33) of the Caucasians. Those with GSTM1 coding for the functional antioxidant enzyme Glutathione S-transferase (GST), had higher CD4 cell count (β=3.48, p=0.034), lower HIV viral load (β=−0.536, p=0.018), and lower mitochondrial 8-oxo-dG (β=−0.28, p=0.03). ART reduced oxidative stress in the participants with the GSTM1 coding for the functional antioxidant enzyme. HIV/HCV co-infected participants with the GSTM1 coding for the functional antioxidant enzyme also had lower HIV viral load, lower 8-oxo-dG and lower rate of apoptosis, but also higher oxidized glutathione. Alcohol consumption was associated with lower HIV viral load but higher oxidized glutathione in those with the GSTM1 genotype coding for the functional antioxidant enzyme.

Conclusion

The GSTM1 genotype coding for the functional antioxidant enzyme is associated with lower HIV disease severity, and with lower oxidative stress, compared to GSTM1 null-allele polymorphism. HCV co-infection and alcohol use may be associated with increased oxidative stress even in the presence of the GSTM1 coding for the functional antioxidant enzyme. The null-gene, on the contrary, appears to have a detrimental effect on immune function, viral load control, and antioxidant status, suggesting a potential benefit from antioxidants in HIV infected patients with the defective gene.

A meta-analysis of the relationship between glutathione S-transferases gene polymorphism and hepatocellular carcinoma in Asian population

The results from the published studies on the association between glutathione S-transferases (GST) gene polymorphism and hepatocellular carcinoma (HCC) in Asian population are still conflicting. GSTM1, GSTT1 and GSTP1 are the mainly mutant sites reported at present. This meta-analysis was performed to evaluate the relationship between GST gene polymorphism and HCC risk in Asians. Association studies were identified from the databases of PubMed, Embase, Cochrane Library and CBM-disc (China Biological Medicine Database) on February 1, 2012, and eligible investigations were synthesized using meta-analysis method. Results were expressed with odds ratios (OR) for dichotomous data, and 95 % confidence intervals (CI) were also calculated. Twenty-five investigations were identified for the analysis of association between polymorphic deletion of GSTM1 and HCC, consisting of 3,547 patients with HCC and 6,132 controls. There was a marked association between GSTM1 null genotype and HCC susceptibility (OR 1.48, 95 % CI 1.19-1.85, P = 0.0004). GSTM1 null genotype was associated with HCC risk in Chinese. Furthermore, null genotype of GSTT1 was associated with HCC susceptibility in Asians. For the GSTM1-GSTT1 interaction analysis, the dual null genotype of GSTM1/GSTT1 was significantly associated with HCC susceptibility in Asian population. However, GSTP1 ile105 val gene polymorphism was not associated with HCC risk in Asian population. In conclusion, GSTM1/GSTT1 null genotype is associated with the HCC susceptibility. However, GSTP1 gene polymorphism is not associated with HCC risk.

Pharmacogenetic analysis of pediatric patients with acute lymphoblastic leukemia: a possible association between survival rate and ITPA polymorphism

Genetic polymorphisms are important factors in the effects and toxicity of chemotherapeutics. To analyze the pharmacogenetic and ethnic differences in chemotherapeutics, major genes implicated in the treatment of acute lymphoblastic leukemia (ALL) were analyzed. Eighteen loci of 16 genes in 100 patients with ALL were analyzed. The distribution of variant alleles were CYP3A4*1B (0%), CYP3A5*3 (0%), GSTM1 (21%), GSTP1 (21%), GSTT1 (16%), MDR1 exon 21 (77%), MDR1 exon 26 (61%), MTHFR 677 (63%), MTHFR 1298 (29%), NR3C1 1088 (0%), RFC1 80 (68%), TPMT combined genotype (7%), VDR intron 8 (11%), VDR FokI (83%), TYMS enhancer repeat (22%) and ITPA 94 (30%). The frequencies of single nucleotide polymorphisms (SNPs) of 10 loci were statistically different from those in Western Caucasians. Dose percents (actual/planned dose) or toxicity of mercaptopurine and methotrexate were not related to any SNPs. Event free survival (EFS) rate was lower in ITPA variants, and ITPA 94 AC/AA variant genotypes were the only independent risk factor for lower EFS in multivariate analysis, which was a different pharmacogenetic implication from Western studies. This study is the first pharmacogenetic study in Korean pediatric ALL. Our result suggests that there are other possible pharmacogenetic factors besides TPMT or ITPA polymorphisms which influence the metabolism of mercaptopurine in Asian populations.

Glutathione S-transferase M1, T1, and P1 polymorphisms and thyroid cancer risk: a meta-analysis

Glutathione S-transferases (GSTs) genetic variants have been explored extensively as a predictive factor for cancer etiology. This meta-analysis aimed to examine the associations GSTM1, GSTT1, and GSTP1 genetic polymorphisms with thyroid cancer risk. PubMed, EMBASE, Cochrane Library, and HuGNet database were searched up to November 2011 using the appropriate terms. Twelve studies regarding GSTM1 null polymorphism (1569 cases and 2907 controls), 11 studies concerning GSTT1 null polymorphism (1515 cases and 2863 controls), and 8 studies on GSTP1 Ile105Val (965 cases and 1604 controls) were included in the meta-analysis. The random effects odds ratio was 1.07 (95% CI: 0.88-1.31; I(2) = 54.1%, P for heterogeneity = 0.013) for the GSTM1 null vs. present genotype and 1.08 (95% CI: 0.75-1.57; I(2) = 81.4%, P for heterogeneity < 0.001) for the GSTT1 null vs. present genotype, and 1.02 (95% CI: 0.70-1.49; I(2) = 74.6%, P for heterogeneity < 0.001) for the GSTP1 Val/Val+Val/Ile vs. Ile/Ile genotype. Similarly, no significant associations were demonstrated for subgroup analyses performed by ethnicity and histological type. In conclusion, these three polymorphisms are unlikely to be major determinants of susceptibility to thyroid cancer. Reasons for potential heterogeneity of effects, which could include true biologic heterogeneity, publication bias, or chance, deserve further investigation. The relationship between these three genes and thyroid carcinoma must be evaluated further with gene-gene and gene-environment interactions.

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.

Null genotype of glutathione S-transferase Tl contributes to colorectal cancer risk in the Asian population: a meta-analysis

BACKGROUND AND AIM

Previous studies investigating the association between the glutathione S-transferase Tl (GSTT1) null genotype and colorectal cancer (CRC) risk in the Asian population have reported controversial results. Thus, a meta-analysis was performed to clarify the effect of the GSTT1 null genotype on CRC risk in the Asian population.

METHODS

A comprehensive study was conducted, and 12 case-control studies were finally included, involving a total of 4517 CRC cases and 6607 controls. Subgroup analyses were performed by the sample size.

RESULTS

A meta-analysis of all 12 studies showed that the GSTT1 null genotype was significantly associated with an increased CRC risk in the Asian population (odds ratio [OR] = 1.10, 95% confidence interval [CI] = 1.02-1.19, the P-value of the OR [P(OR)] = 0.02, the value of the heterogeneity analysis [I(2)] = 42%). A more obvious association was observed after the heterogeneity was eliminated by excluding one study (OR = 1.15, 95% CI: 1.06-1.25, P(OR) = 0.001, I(2) = 0%). This association was further identified by both subgroup analyses and a sensitivity analysis.

CONCLUSIONS

This meta-analysis suggests that the GSTT1 null genotype contributes to an increased colorectal cancer risk in the Asian population.