Avaliação dos níveis da citocina pró-inflamatória fator de necrose tumoral-α em pacientes com diabetes tipo 2 e sua relação com variações genéticas de enzimas antioxidantes e obesidade / Evaluation of proinflammatory cytokine tumor necrosis factor-α levels in obese vs nonobese patients with type 2 diabetes and their relationship to CAT C-262T polymorphism

Introdução: Diabetes tipo 2 (DM2) é um distúrbio multifatorial caracterizado pelo aumento dos níveis de radicais livres. Tanto o estresse oxidativo quanto a obesidade contribuem para um estado inflamatório da doença, principalmente pelo aumento da citocina TNF-α. Sabendo-se que a genética individual pode contribuir para o estresse oxidativo, o estudo avaliou o impacto das variações genéticas de enzimas antioxidantes C262T no gene CAT e polimorfismos nulos dos genes GSTM1 e GSTT1 nos níveis de TNF-α, assim como, avaliou se as variantes genéticas atuariam sinergicamente com a obesidade aumentando os níveis da citocina em diabéticos da Grande Vitória/ES, Brasil.Métodos: O polimorfismo no gene CAT foi avaliado pela técnica PCR/RFLP e nos genes GSTM1 e GSTT1 por PCR multiplex, em 56 pacientes, sendo 28 obesos e 28 não obesos. Níveis de TNF-α foram medidos pela técnica de ELISA sanduíche.Resultados: Frequências das variantes nulas de GSTM1 e GSTT1 foram 44,6% e 17,9%, respectivamente. As frequências genotípicas C262T-CAT foram 73,2%, 25% e 1,8% para homozigoto normal, heterozigoto e homozigoto polimórfico, respectivamente. Não houve associação entre genótipos polimórficos e aumento dos níveis de TNF-α, assim como, não foi demonstrado aumento significante da citocina quando avaliado o sinergismo entre obesidade e genética individual do paciente.Conclusão: Níveis de TNF-α não se elevam em diabéticos tipo 2 na presença dos polimorfismos nos genes CAT, GSTM1 e GSTT1, e a obesidade não atua no aumento dessa citocina na população estudada, separadamente ou em conjunto com a genética individual de variantes nos genes CAT, GSTM1 e GSTT1.

Introduction: Type 2 diabetes is a multifactorial disorder characterized by increased levels of free radicals. Both oxidative stress and obesity contribute to an inflammatory state of the disease, mainly by increasing the levels of the proinflammatory cytokine tumor necrosis factor-α (TNF-α). Considering that personal genetics may contribute to oxidative stress, this study assessed the impact of CAT C-262T polymorphism and GSTM1 and GSTT1 null polymorphisms on TNF-α levels in patients with type 2. diabetes. The study also evaluated whether the genetic variants act synergistically with obesity to increase TNF-α levels in patients with diabetes from Grande Vitória, Brazil.Methods: Fifty-six patients were included, of whom 28 were obese and 28 were nonobese. The CAT gene polymorphism was assessed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, whereas GSTM1 and GSTT1 polymorphisms were assessed using multiplex PCR. TNF-α levels were measured using the sandwich ELISA technique.Results: Frequencies of GSTM1 and GSTT1 null polymorphisms were 44.6% and 17.9%, respectively. The genotype frequencies of CATC-262T polymorphism were 73.2%, 25.0%, and 1.8% for normal homozygote, heterozygote, and polymorphic homozygote, respectively. Polymorphic genotypes were not associated with increased TNF-α levels, and there was no significant increase in TNF-α levels when evaluating the synergism between obesity and personal genetics.Conclusion: The presence of CAT, GSTM1, and GSTT1 gene polymorphisms was not associated with increased TNF-α levels in patients with type 2 diabetes. Obesity alone or combined with personal genetics of CAT, GSTM1, and GSTT1gene polymorphisms did not promote increased TNF-α levels in the study population.

GSTM1 null polymorphism prevalence in tobacco users, oral leukoplakia and oral squamous cell carcinoma patients in South Indian population: A polymerase chain reaction study.

Context: Tobacco abuse is a well‑known risk factor for potentially malignant disorders as well as oral squamous cell carcinoma. Factors that influence tobacco‑exposed individuals developing a malignancy may include the combination of total tobacco exposure and genetic susceptibility. Aim: This study was undertaken to determine the prevalence of the glutathione S‑transferase M1 (GSTM1) null polymorphism in oral leukoplakia and oral squamous cell carcinoma patients in South Indian population. Settings and Design: This case–control study was conducted in hospital setting on South Indian population. Materials and Methods: About 280 subjects with history of tobacco use, oral leukoplakia, oral squamous cell carcinoma were included in this study. Three milliliter of blood was collected and transported under cold cycle and taken for evaluation of GSTM1 null polymorphism using multiplex polymerase chain reaction. Results and Discussion: On comparing the prevalence of GSTM1 null polymorphism among the group with subjects with habits and no oral lesions, oral leukoplakia, and oral squamous cell carcinoma, it was observed that there was a statistically significant association between GSTM1 null polymorphism and the different groups (P < 0.01). Conclusion: The lack of GSTM1 activity would make the oral tissues more susceptible to action of tobacco carcinogens and to the development of a high‑grade level of dysplasia in oral leukoplakia and thereby increases the susceptibility of lesion to undergo malignant changes.

Relationship between the Glutathione-S-Transferase P1, M1, and T1 Genotypes and Prostate Cancer Risk in Korean Subjects

PURPOSE: The glutathione-S-transferase (GST)P1, GSTM1, and GSTT1 genotypes have been associated with an increased risk of prostate, bladder, and lung cancers. The aim of this study was to investigate the association between the GSTP1, GSTM1, and GSTT1 genotypes and the risk of prostate cancer in Korean men. MATERIALS AND METHODS: The study group consisted of 166 patients with histologically confirmed prostate cancer. The control group consisted of 327 healthy, cancer-free individuals. The diagnosis of prostate cancer was made by transrectal ultrasound-guided biopsy. Patients with prostatic adenocarcinoma were divided into organ-confined ( or =pT3) subgroups. The histological grades were subdivided according to the Gleason score. The GSTP1, GSTM1, and GSTT1 genotypes were determined by using polymerase chain reaction-based methods. The relationship among GSTP1, GSTM1, and GSTT1 polymorphisms and prostate cancer in a case-control study was investigated. RESULTS: The frequency of the GSTM1 null genotype in the prostate cancer group (54.2%) was higher than in the control group (odds ratio=1.53, 95% confidence interval=1.20-1.96). The comparison of the GSTP1, GSTM1, and GSTT1 genotypes and cancer prognostic factors, such as staging and grading, showed no statistical significance. CONCLUSIONS: An increased risk for prostate cancer may be associated with the GSTM1 null genotype in Korean men, but no association was found with the GSTT1 or GSTP1 genotypes.

Detection of GSTM1 polymorphism in patient with nasopharyngeal carcinoma by real-time PCR.

Objective: To investigate whether the real-time polymerase chain reaction (R-PCR) assay with SYBR green I and melting curve analysis could be used for glutathione S-transferase M1 gene (GSTM1) polymorphism detection in Thai nasopharyngeal carcinoma (NPC) patients by comparing the results of this assay with the conventional PCR (C-PCR) assay. Methods: DNA samples from peripheral blood leukocytes of 60 Thai NPC patients were investigated in this study. GSTM1 polymorphism [GSTM1 normal genotype (GSTM1+) and GSTM1 null genotype (GSTM1-)] were examined by using the R-PCR assay with SYBR green I and melting curve analysis and the C-PCR assay. Results: The results of GSTM1 polymorphism detection by the R-PCR assay were in concordance with the C-PCR assay (k = 1.0). Twenty-six individuals with GSTM1+ in the R-PCR assay showed 2 peaks of melting point at 82.5oC and 87.5oC that correlated with the appearance of 2 DNA bands of GSTM1 [215 base pair (bp)] and b-globin (268 bp) in the C-PCR assay, respectively. In addition, thirty-four individuals with GSTM1- in the R-PCR assay showed only 1 peak of melting point at 87.5oC that correlated with the appearance of 1 DNA band of b-globin (268 bp) in the C-PCR assay. Moreover, we found that the R-PCR assay was a faster and safer method for detection of GSTM1 polymorphism than the C-PCR assay. Conclusion: The present study suggests that the R-PCR assay with SYBR Green I and melting curve analysis may be a useful screening tool for more convenient, rapid, reliable, and safer detection of GSTM1 polymorphism in Thai NPC as compared to the C-PCR assay.

Organochlorines, Glutathione S-transferase M1 Genetic Polymorphisms and Risk of Breast Cancer / 环境与健康杂志

Objective To study the potential effect of gene-environment interaction between glutathione S-transferase M1 (GSTM1) and serum organochlorines residues on the risk of breast cancer in women, in China. Methods Seventy newly pathologically diagnosed female patients with breast cancer from September 2006 to October 2007 were selected as the cases from five large hospitals in Tangshan. The controls were identified at the same hospital as cases. 1∶1 matched case-control study. Between the cases and controls, the difference of age was not over two years and the residence was similar. The organochlorine residues levels in the serum were measured by gas chromatography (GC). Genotypes of GSTM1 polymorphisms were analyzed by multiplex allele-specific polymerase chain reaction (PCR). Interaction indexes (?) were calculated to determine the type of gene-environment interaction. Results After confounding factors adjusted, the result showed that interaction existed in genetic polymorphisms of GSTM1 and DDT, HCH residues, and interaction indexes (?) value were 1.237 and 1.379. Conclusion GSTM1 genetic polymorphisms and DDT, HCH may present an interaction in the development of breast cancer.

Distribution of Polymorphisms and Linkage of GSTM1 and GSTM3 Genes in Healthy Cantonese in Southern China / 环境与健康杂志

Objective To determine the prevalence of the polymorphisms of GSTM1 and GSTM3 genes in target population in Guangdong province and to investigate the linkage between the two genes and their association with the family history distribution of the target population. Methods Polymerase chain reaction-restriction (PCR)-2% agarose gel electrophoresis and PCR-12% PAGE electrophoresis approaches were employed to detect the genotype of the GSTM1 and GSTM3. The data was analyzed with SPSS10.0 software. Results The frequency of GSTM1(-) genotype was 56.8%(n=597). The frequency of genotype of GSTM3*A-*A,*A-*B,*B-*B were 62.3%,25.8%,11.9% respectively. Conclusion A linkage between the GSTM1 and GSTM3 gene is showed in the present paper. The analysis of logistic regression shows that the expression of homozygote for GSTM3*B-*B gene is correlated with the family history of coronary heart disease in the target population.

GSTM1 and GSTP1 Polymorphisms as Potential Factors for Modifying the Effect of Smoking on Inflammatory Response

Inflammation has been known to be an important underlying condition for development of various diseases including cancer. The aims of this study were to investigate whether tobacco smoke exposure increases the level of inflammation biomarkers and the GSTM1 and GSTP1 gene polymorphisms are associated with inflam matory response due to tobacco smoke exposure. We measured urinary cotinine level in 300 healthy university students. Total serum TNF-alpha levels and blood WBC counts were determined to evaluate inflammatory response. Allelic loss of the GSTM1 and the GSTP1 (Ile105Val) polymorphism were determined by PCR and RFLP. Tobacco smoke exposure was found to be associated with increase of both TNF-alpha level and WBC count. Particularly, smokers with combination of GSTM1 null and GSTP1 AG or GG genotypes showed higher TNF-alpha level than those with the other genotype combinations (p=0.07). This result suggests that smoking may induce inflammation measured as TNF-alpha level or WBC count and combinations of the GSTM1 and GSTP1 polymorphisms may modify the effect of smoking on serum TNF-alpha level.

GSTM1 and GSTP1 Polymorphisms as Potential Factors for Modifying the Effect of Smoking on Inflammatory Response

Inflammation has been known to be an important underlying condition for development of various diseases including cancer. The aims of this study were to investigate whether tobacco smoke exposure increases the level of inflammation biomarkers and the GSTM1 and GSTP1 gene polymorphisms are associated with inflam matory response due to tobacco smoke exposure. We measured urinary cotinine level in 300 healthy university students. Total serum TNF-alpha levels and blood WBC counts were determined to evaluate inflammatory response. Allelic loss of the GSTM1 and the GSTP1 (Ile105Val) polymorphism were determined by PCR and RFLP. Tobacco smoke exposure was found to be associated with increase of both TNF-alpha level and WBC count. Particularly, smokers with combination of GSTM1 null and GSTP1 AG or GG genotypes showed higher TNF-alpha level than those with the other genotype combinations (p=0.07). This result suggests that smoking may induce inflammation measured as TNF-alpha level or WBC count and combinations of the GSTM1 and GSTP1 polymorphisms may modify the effect of smoking on serum TNF-alpha level.

Genetic Polymorphism of Cytochrome P4501A1 Exon 7 and Glutathione S-Transferase M1 in the Head and Neck Squamous Cell Carcinoma Patients / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: An individual difference in susceptibility to chemically induced carcinomas is in part ascribed to genetic differences of metabolic activity of environmental procarcinogens. The cytochrome P450 family (CYPs) and glutathione S-transferase (GST) have been reported to be associated with human cancers related with smoking. The purpose of this study was to determine the frequencies of the genotypes of CYP1A1 and GSTM1 genes in healthy control of Koreans and to identify the high-risk genotypes of these metabolic genes in head and neck cancer patients. MATERIALS AND METHOD: The genetic polymorphism of CYP1A1 exon 7 and GSTM1 genes were analysed in a group of 115 healthy Koreans and 107 head and neck squamous cell carcinoma patients using allelic-specific polymerase chain reaction. RESULTS: The genotypes of CYP1A1 exon 7 (Ile/Ile, Ile/Val and Val/Val) were 59.1%, 36.5% and 4.4%, respectively, in the healthy control group, and 57.0%, 31.8% and 11.2%, respectively, in the cancer patients . The distributions of GSTM1 [GSTM1 (-), GSTM1 (+)] in healthy control group were 46.1%, 53.9% respectively, and 53.3%, 46.7%, respectively, in the cancer patients. The relative risk (odds ratio) for combination of CYP1A1 Val/Val and GSTM1 (-) genotype was estimated to be 5.17, taking the risk of combined genotype Ile/Ile and GSTM1 (+) as a reference in cancer patients. CONCLUSION: These results suggest that the genetic polymorphisms of CYP1A1 exon 7 and GSTM1 were an important major factor in determining the individual susceptibility to head and neck squamous cell carcinoma in Koreans.