Influence of glutathione-related genetic variants on the oxidative stress profile of Mexican patients with psychotic disorders

Objective: The clinical trajectories of patients with psychotic disorders have divergent outcomes, which may result in part from glutathione (GSH)-related high-risk genotypes. We aimed to determine pharmacokinetics of clozapine, GSH levels, GSH peroxidase (GPx) activity, gene variants involved in the synthesis and metabolism of GSH, and their association with psychotic disorders in Mexican patients on clozapine monotherapy and controls. Methods: The sample included 75 patients with psychotic disorders on clozapine therapy and 40 paired healthy controls. Plasma clozapine/N-desmethylclozapine, GSH concentrations, and GPx activity were determined, along with genotyping of GCLC and GSTP1 variants and copy number variations of GSTP1, GSTT1, and GSTM1. Clinical, molecular and biochemical data were analyzed with a logistic regression model. Results: GSH levels were significantly reduced and, conversely, GPx activity was higher among patients than controls. GCLC_GAG-7/9 genotype (OR = 4.3, 95%CI = 1.40-14.31, p = 0.019) and hetero-/homozygous genotypes of GCLC_rs761142 (OR = 6.09, 95%CI = 1.93-22.59, p = 0.003) were found to be risk factors for psychosis. The genetic variants were not related to clozapine/N-desmethylclozapine levels or metabolic ratio. Conclusions: GCLC variants were associated with the oxidative stress profile of patients with psychotic disorders, raising opportunities for intervention to improve their antioxidant defenses. Further studies with larger samples should explore this proposal.

Expressions of glutathione S-transferases M1 and glutathione S-transferases M2 in follicular thyroid carcinoma and their significances / 肿瘤研究与临床

Objective:To investigate the expressions of glutathione S-transferases M1 (GSTM1) and glutathione S-transferases M2 (GSTM2) in follicular thyroid carcinoma (FTC) and their clinical significances.Methods:Gene expression profile of GSE82208 generated from 52 human thyroid samples, including 27 cases of FTC and 25 cases of follicular adenoma (FA) were collected from Gene Expression Omnibus (GEO) database. The gene matrix data were extracted and analyzed, and then differentially expressed genes (DEG) between FTC and FA were identified by using Limma package. Immunohistochemical SABC method was used to detect the expression levels of GSTM1 and GSTM2 proteins in FTC tissues and FA tissues collected from 56 FTC samples and 56 FA samples in Dandong First Hospital of Liaoning Province from January 2000 to December 2020. The relationship between GSTM1 and GSTM2 was analyzed; the association of expression levels of GSTM1 and GSTM2 with the clinicopathological factors of FTC patients was also analyzed.Results:Based on the GEO database, a total of 40 DEG were identified, including 9 up-regulated DEG (GSTM1, GSTM2, COL6A2, CUX2, CLUH, TSC2, OGDHL, ACADVL, SDHA) and 31 down-regulated DEG in FTC. The immunohistochemistry results of samples resected showed that the positive rates of GSTM1 and GSTM2 proteins in FTC tissues were higher than those in FA tissues [71.4% (40/56) vs. 23.2% (13/56), 80.4% (45/56) vs. 14.3% (8/56)], and differences were statistically significant ( χ2 values were 26.11 and 49.03, both P < 0.01). The expressions of GSTM1 and GSTM2 in FTC tissues were correlated with clinical staging, invasion degree and distant metastasis (all P < 0.05), but not with gender, age and tumor diameter (all P>0.05). There was a positive correlation between GSTM1 and GSTM2 proteins expressions in FTC ( r = 0.384, P = 0.004). Conclusions:The expression levels of GSTM1 and GSTM2 in FTC are increased. The interaction between GSTM1 and GSTM2 proteins can be involved in the development and progression of FTC.

Combined GSTM1 and GSTT1 null genotypes are strong risk factors for atherogenesis in a Serbian population

Abstract Oxidative stress (OS) plays an important role in atherogenesis and since glutathione S-transferases (GSTs) provide protection against OS, we have tested the hypothesis that deletion polymorphisms in two GSTs (GSTM1 and GSTT1) may affect the risk of developing atherosclerosis. A total of 382 individuals (200 patients with atherosclerosis and 182 healthy controls) were included in this association study. Genomic DNA was isolated from peripheral blood cells or from buccal epithelial cells and genotyping was performed using multiplex-PCR or real-time PCR methods. GSTM1 null genotype was significantly more frequent in atherosclerotic patients than in controls (52.0% vs 34.1%) and individuals with the GSTM1 null genotype had an approximately 2-fold increase in atherosclerosis risk (OR: 2.1, 95%CI=1.39-3.17, P=0.0004). GSTT1 null genotype alone did not show a statistically significant effect on atherosclerosis risk modulation, but the association approached significance (OR: 1.57, 95%CI=0.94-2.64, P=0.08). The combined analysis showed that the presence of both genes had a protective effect against atherosclerosis (OR=0.55, 95%CI=0.37-0.83, P=0.005) while double null genotypes led to a robust atherosclerosis risk increase (OR: 8.14, 95%CI= 2.41-27.51, P < 0.0001). This study demonstrated that the GSTM1 null and combined GSTM1/GSTT1 null genotypes are susceptibility factors for development of atherosclerosis in a Serbian population.

Polymorphism of glutathione S-transferase M1 and T1 genes and susceptibility to psoriasis disease: A study from North India

Background: Increased oxidative stress and resulting inflammation has been emphasized as a factor in the pathogenesis of many diseases including psoriasis. Glutathione S-transferases (GSTs) protect against oxidative stress, inflammation, and genotoxicity. Polymorphisms in the GST genes may lead to an imbalance in pro- and antioxidant systems resulting in the increased production of reactive oxygen species that could influence the pathogenesis of psoriasis. Aim: The aim of this study was to investigate the association between GSTs (GSTM1 and GSTT1) gene polymorphism in patients with chronic plaque psoriasis as a factor in the susceptibility and development of psoriasis. Materials and Methods: We assessed 128 patients with psoriasis and 250 age- and sex-matched healthy controls. Genomic DNA was extracted from peripheral blood by the phenol chloroform method. The null GSTT1 and GSTM1 genotypes were identified by multiplex polymerase chain reaction (PCR) method. Results: The null genotype of GSTM1 and GSTT1 was seen in 45.3% and 40.6% in psoriasis patients whereas in the controls it was 34.4% and 20.0%, respectively. A significant association was seen between the null alleles of the GSTT1 (OR = 2.74) and GSTM1 (OR = 1.58) alone or in combination with tobacco use (P < 0.001) and psoriasis risk. The presence of both null genotypes of GSTM1 and GSTT1 further increased the risk of psoriasis (OR = 3.52) when compared with the positive genotypes of GSTM1 and GSTT1. Limitations: A major limitation of this study was the small sample size. A large epidemiological study is necessary to confirm these findings. Conclusions: The null genotype of GSTT1 is a strong predisposing factor for psoriasis in North India.

Asociación entre polimorfismos de Glutation s-transferasa y cáncer cérvico uterino / Association between polymorphisms of Glutathione s-transferase and cervical cancer

Introducción: entre los factores de riesgo que favorecen la aparición de las lesiones cérvico uterinas, se encuentran la infección por virus de papiloma humano, la promiscuidad, el uso de anticonceptivos orales y el hábito de fumar. No obstante, varias investigaciones refieren que los polimorfismos genéticos podrían contribuir al desarrollo y progresión del cáncer cérvico uterino. Objetivo: identificar en la bibliografía revisada, la frecuencia de asociación de los polimorfismos de Glutation s - transferasa con el cáncer cérvico uterino y con factores de riesgo que inciden en la patología. Métodos: se realizó una extensa revisión de la literatura especializada a través de los buscadores en base de datos de PubMed, EBSCO, NCBI y BVS. Resultados: se constató la variabilidad en los reportes de las frecuencias alélicas de los genotipos GSTM1 y T1 en distintas poblaciones. Se corroboró en varios estudios revisados el hallazgo de asociación entre los genotipos GSTM1 y T1 nulos y cáncer cérvico uterino y, de igual forma con el consumo de tabaco y anticonceptivos orales por tiempo prolongado. Conclusiones: la bibliografía sobre el tema pone en evidencia que los genes que codifican la enzima Glutation s - transferasa intervienen en la protección celular contra los efectos citotóxicos, de manera que cuando éstos presentan alteración se afecta la actividad enzimática, lo que predispone a una mayor susceptibilidad al cáncer(AU)

Introduction: Among risk factors that lead to uterine cervix lesions we can find the human papilloma virus infection, promiscuity, use of oral contraceptive and smoking habit. However, several researches refer that genetic polymorphism could be related to the development and progression of the uterine cervix cancer. Objective: Identify the association of glutathione S- transferases polymorphism with uterine cervix cancer and risk factors relate with this disease, in the revise bibliography. Method: An extensive review was made of the specialized literature using web search in database PubMed, EBSCO, NCBI and BVS. Result: The variability of the allelic frequency of the GSTM1 and T1 genotypes in different populations was confirmed. Besides the association between null GSTM1 and T1 with uterine cervix cancer was corroborated. In addition, this association with smoking habit and the use of oral contraceptive for long time was corroborated. Conclusions: Consulted bibliography shows that genes encoding glutahione S- transferases enzyme contribute to the cellular protection against cytotoxic effects, therefore, alterations in these genes affect the enzymatic activity lead to a major susceptibility to suffer cancer(AU)

Glutathione S transferase (GSTP 1, GSTM 1, and GSTT 1) gene polymorphisms in Egyptian patients with acute myeloid leukemia.

BACKGROUND: The super family of glutathione S‑transferases (GSTs) is composed of multiple isoenzymes with significant evidence of functional polymorphic variation. GSTs detoxify potentially mutagenic and toxic DNA‑reactive electrophiles, including metabolites of several chemotherapeutic agents, some of which are suspected human carcinogens. Polymorphisms within the phase II metabolizer enzymes GST T1, GST M1, and GST P1 affect the body’s ability to detoxify a range of potential leukemogens encountered in the environment. AIM OF WORK: To address how differences in the human GST isoenzyme expression patterns influence cancer susceptibility, prognosis, and treatment. PATIENTS AND METHODS: A total of 50 patients with acute myeloid leukemia (AML), as well as 50 age and sex matched apparently healthy volunteers were genotyped for GSTP 1, GSTM 1, and GSTT 1 gene polymorphisms using polymerase chain reaction‑restriction fragment length polymorphism (PCR‑RFLP) and conventional polymerase chain reaction (PCR), respectively. RESULTS: For GSTP1 313 A → G (GSTP1 Ile105Val) polymorphism, It was found that the wild genotype (AA) was significantly higher among control subjects (P value = 0.0277), while the frequency of heteromutant genotype (AG) and mutant G allele (AG + GG) was significantly higher among patients (P value = 0.0402, P value = 0.0277, respectively). For GSTM1 and GSTT1gene, we found statistically significantly higher frequency among patients regarding homozygous gene deletion (P value = 0.0005). CONCLUSION: We demonstrated that GSTM1 null or GSTT1 null genotypes may be considered independent risk factors for AML with no impact on prognosis and GSTP1 * 105 genotype is a prognostic factor, adding independent information to the routine laboratory parameters and cytogenetic and molecular alterations of the tumor cells.

Meta-analysis of the association between GSTT1 and the susceptibility to colorectal cancer among ;Chinese population / 国际肿瘤学杂志

Objective To assess the association between glutathione S-transferase T1 (GSTT1 )gene and the susceptibility of colorectal cancer among Chinese population.Methods Clinical controlled trials of the association between GSTT1 and the susceptibility of colorectal cancer among Chinese population were searched in PubMed,EMBase,Cochrane Library,China Biology Medicine disc,VIP database,China National Knowledge Infrastructure and Wanfang database.According to the inclusion and exclusion criteria,data extraction and quali-ty assessment were done by two researchers independently.Outcomes were pooled with RevMan 5.1 .Results 326 studies were found and 10 clinical controlled trails including 2 983 cases of colorectal cancer and 4 386 cases of healthy objects were included in this analysis.The results of Meta-analysis showed that the lack of GSTT1 gene is associated with colorectal cancer susceptibility (RR =1 .11 ,95%CI:1 .06-1 .17,Z =4.26,P <0.000 1 ). Conclusion The loss of GSTT1 increase the risk of colorectal cancer among Chinese population.

Genetic Polymorphisms of Glutathione S-transferase M1 and T1 and Evaluation of Oxidative Stress in Patients with Non-small Cell Lung Cancer / 中国医科大学学报

Objective To investigate the genetic polymorphisms of the glutathione S-transferase M1 and T1 genes(GSTM1 and GSTT1),and eval-uate the oxidative damage in patients with non-small lung cancer(N-SCLC). Methods A total of 110 patients with N-SCLC and 100 healthy indi-viduals were recruited in this case-control study. Multiplex polymerase chain reaction(PCR)analysis was used to identify the genotypes. The activi-ty of malondialdehyde(MDA),nitric oxide(NO),and the total antioxidant capacity(T-AOC)were detected by spectroscopic analysis using assay kits. Results The frequencies of the GSTM1,T1,and GSTM1/T1 null genotypes in the patient group were significantly higher than those in control group(OR1=2.071,P1=0.009;OR2=1.900,P2=0.024;OR3=3.258,P3=0.003). The activity of MDA and NO were obviously higher in the pa-tient group compared with the control group(P<0.001),and T-AOC was obviously lower in patient group than those in control group(P<0.001). The activity of MDA,and NO were higher but the T-AOC were lower in patients with GSTM1,T1 and GSTM1/T1 null genotypes than those in pa-tients with GSTM1,T1 and GSTM1/T1 present genotypes(P<0.001). Conclusion Our results suggest that oxidative damage may play a impor-tant role in patients with N-SCLC,and the N-SCLC patients with GSTM1and GSTT1deletion genotypes are more susceptible to oxidative damage.

Impact of GSTM1 and GSTP1 polymorphism on lung cancer patients treated with platinum-based chemotherapy / 重庆医学

Objective To investigate the relationship between glutathione S-transferases P1(GSTP1)Ile105Val and glutathione S-transferases M1(GSTM1)single nucleotide polymorphisms(SNP) and the sensitivity to chemotherapy among patients with ad-vanced non-small cell lung cancer(NSCLC) .Methods We used gene sequencing analysis to determine the SNP of GSTP1 Ile105Val and PCR analysis to GSTM1 in DNA from peripheral lymphocytes of NSCLC patients .Totally 89 patients with NSCLC were trea-ted with platinum-based chemotherapy ,and clinical response was evaluated after 2 cycles .The association between GSTP1 Ile105Val and GSTM1 SNP and chemosensitivity were analyzed .Results The overall response rate was 29 .2% .Chemotherapy re-sponse did not show statistically significant differences between the wild genotypes and the variant genotypes for the GSTP1 Ile105Val and GSTM1 gene(P>0 .05) .Conclusion The polymorphisms of GSTP1 Ile105Val and GSTM1 may be not associated with sensitivity to chemotherapy in NSCLC patients .

Relationship of DNA methylation, mRNA transcription and protein expression of glutathione-S-transferases-P1 gene and coal-pollution-borne endemic arsenism / 中国地方病学杂志

Objective To investigate DNA methylation in the promoter region,mRNA transcription and protein expression of glutathione-S-transferases-P1 (GSTP1) gene and their relation with arsenism.Methods In endemic coal-pollution-borne arsenism area,Jiaole village of Xinren county,Guizhou province,according to the diagnostic criteria of endemic arsenism(WS/T 211-2001),123 cases with endemic arsenism were selected and divided into three groups (mild arsenism group:42 cases,moderate arsenism group:41 cases and severe arsenism group:40 cases).Forty seven residents were selected as controls in a village about 12 km away from the endemic arsenism area.With the informed consent principle,peripheral blood of all respondents was collected in order to analyze DNA methylation and check mRNA.DNA methylation of GSTP1 gene promoter region in peripheral blood was assayed by PCR,and GSTP1 mRNA expression was assayed using real-time quantitative PCR.In addition,other cutaneous specimens originated from 53 cases with arsenism that accepted surgical treatment voluntarily were taken.Of these specimens,general pathological changes were 28 cases,precancerous 20 cases and cancerous 5 cases.Skin tissues of 15 cases of non-tumor surgery patients without abnormal pathological changes were as control group.GSTP1 protein expression in the skin tissue was detected using immunohistochemistry (IHC).Results Among different groups of arsenic poisoning,the positive rate of DNA methylation of GSTP1 gene was 28.57％(12/42) in the mild group,57.10％ (23/41) in the moderate group and 65.00％ (26/40) in the severe group.Compared with the control group (6.38％,3/47),the difference was statistically significant (x2 =7.792,26.000,33.412,all P ＜ 0.01).Among different groups of arsenic poisoning diagnosed by dermapathology,the positive rate of DNA methylation of GSTP1 gene was 21.43％(6/28) in the general pathological change group,50.00％(10/20) in the precancerous group and 80.00％(4/5) in the cancerous group.Compared with the control group(6.67％,1/15),the difference was statistically significant (x2 =3.562,7.468,10.756,all P ＜ 0.05).It showed that the positive rate of DNA methylation of GSTP1 gene increased with aggravation of the disease and dermatic lesion of arsenism (tendency x2 =38.239,x2 =13.659,all P ＜ 0.01).Compared with the control group(0.184 26),the expressions of GSTP1 mRNA in peripheral blood in moderate (0.087 77) and severe arsenic poisoning groups (0.056 93) were significantly reduced(all P ＜0.01),and that of severe group was significantly lower than that of the moderate group (P ＜ 0.01) ; compared with the control group(0.338 45) and the general lesion group(0.276 74),GSTP1 mRNA expression was significantly reduced in precancerous lesion group(0.104 81) and cancerous group(0.043 70),in which the cancerous group was significantly lower than that of the precancerous lesions.The difference of skin tissue GSTP1 protein expression rate between groups was statistically significant (x2 =20.948,P ＜ 0.05),in which the difference between the precancerous lesion group(65.00％,13/20),the cancer group (40.00％,2/5) and the control group(100.00％,15/15)was statistically significant (x2 =12.183,11.778,P ＜ 0.01).Spearman correlation analysis showed that the degree of skin lesion and the level of GSTP1 protein expression was negatively correlated (r =-0.520,P ＜ 0.05).Groups were divided according to DNA methylation of GSTP1 gene,and the mRNA and protein expression of GSTP1 in methylation group(0.038 40,57.14％) was significantly lower compared with that of unmethylated group(0.187 07,95.74％; Z =9.032,x2 =23.134,all P ＜ 0.01).Conclusions Arsenism may lead to DNA methylation of human GSTP1 gene promoter region,thereby inhibiting expression of mRNA and protein.GSTP1 gene plays an important role in arsenism or carcinogenic process.

Regulation of Acrylamide Induced µ-Class Glutathione-S-Transferases in Mice Testis by the Treatment of Hybanthus Enneaspermus Active Principles.

The present study was aimed to analyse the effect of acrylamide and Hybanthus enneaspermus leaf extract active principles on mice testis glutathione-s-transferases (GST; EC 2.5.1.18). These enzymes play a role in biotransformation of electrophilic compounds that cause damage to cells by conjugating with the substrate glutathione. Hybanthus enneaspermus, a spade flower, is an erect shrub of violaceae family, having free radical scavenging activity. Acrylamide is a known neurotoxicant that cause damage to almost all cells including liver, testis, brain and kidney. The GSTs purified from mice testis using glutathionyl linked agarose affinity chromatography were analyzed by using SDS-PAGE and were resolved into four sub units i.e. Yc, Yb, Yβ &Yδ. Also these subunits expression were confirmed by western blot analysis. During experimentation to analyze the effect of Hybanthus enneaspermus active principle (HE) mice were subjected to both acrylamide (AC) and also mixture of HE and AC. This exposure significantly altered the specific activity of mice GSTs in testis. Polyclonal antibodies produced against purified GSTs of mice testis on immunoblot analysis showed significant increase of μclass GSTs (Yb & Yβ) based on dose and time dependent manner. Therefore the present research of Hybanthus enneaspermus treatment on mice testis showed that, regulation of synthesis of μ-GSTs was depending on the dose of acrylamide concentration and also the active principles of HE. Hence it is proposed that μ-GSTs may be used as tumour markers for testis carcinoma, since their production is variable due to the increased dose concentration of synthetic chemical acrylamide and its regulation by plant product, HE.

Relationship between glutathione S-transferase GSTO 1 Glu155 △Glu genetic polymorphism and arsenic poisoning caused by coal-burning / 中国地方病学杂志

ObjectiveTo investigate glutathione S-transferase GSTO 1 Glu155△Glu genetic polymorphism and risks of arsenic poisoning caused by coal-burning in Guizhou.Methods GSTO1 Glu155 △Glu gene polymorphism was analyzed by polymerase chain reaction-with confronting two-pair primers among one hundred and thirty arsenic poisoning patients and one hundred and thirty healthy controls.The results were verified by DNA sequencing.The association between different genotypes and arsenic poisoning was analyzed by unconditional Logistic regression model.ResultsThe results of Glu/Glu and Glu/△Glu genotype detected by this method were consistent with those of DNA sequencing.The frequencies of GSTO1 Glu/Glu genotype and Glu/△Glu genotype were 94.85％(92/97) and 5.15％(5/97) in the patients,99.15％(117/118) and 0.85％(1/118) in the controls,respectively.The difference was statistically significant(x2 =3.896,P ＜ 0.05).△Glu/△Glu genotype was not found in both patients and controls.After age and sex adjusting,GSTO1 Glu155 △Glu polymorphism was found to be a risk factor of arsenic poisoning [odds ratio (OR) =1.85,95％ confidence interval (CI):1.39 - 17.48].ConclusionsThe study finds that GSTO1 Glu 155 △ Glu polymorphism is associated with risk of arsenic poisoning.The relationship between them should be further studied through increasing sample size.

Gene polymorphisms and distribution features of glutathione S-transferase Omega-1 gene in Ala140Asp site in 16 Chinese populations / 中国地方病学杂志

Objective To investigate gene polymorphisms and distribution features of glutathione Stransferase Omega-1 (GSTO 1 ) gene in Ala 140Asp site in 16 Chinese populations.MethodsA total of 1369 samples were from the human genome project(HGP)-the establishment and preservation program of Chinese minority genetic resources.The phenotypes of Ala/Ala (C/C),Ala/Asp (C/A),and Asp/Asp (A/A) of GSTO1 Ala140Asp were determined by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP).With analysis of molecular variance(AMOVA),the genetic variation levels among nations and regions were analyzed by estimating the evolutionary distance of alleles or genotypes.ResultsOf the 1369 individuals analyzed,979 (71.51％) were carriers of the wild homozygous allele Ala/Ala(C/C),365 (26.66％) were heterozygotes Ala/Asp(C/A) and 25 (1.83％) were mutant homozygotes Asp/Asp(A/A),with an overall frequency of the GSTO 1 mutant allele A 15.16％ [ (365 +50)/( 1369 × 2)].AMOVA analysis showed that the difference was statistically significant(P ＜ 0.05) of genetic variations of GSTO1 gene Ala140Asp among the 14 ethnic groups,and was significant between the northem and southern populations (P ＜ 0.05 ).Conclusion In different regions and populations the GSTO1Ala140Asp mutant allele frequencies are different.

Current research of effect of glutathione S-transferases on eye oxidative damage / 中华实验眼科杂志

Glutathione S-transferases (GSTs) are large super-gene family.It is traditionally thought to be a kind of electrophilic detoxification substance.However,recent research showed that it has a powerful antioxidant role,but its gene polymorphism is also a risk factor of variety diseases.Researches verified that GSTs are widely found in the epithelial tissue in human and eye tissues,such as iris,ciliary,trabecular meshwork,lens,macula and retina.GSTs play strong preventive and treating roles for many oxidative-induced eye diseases,including primary open-angle glaucoma ( POAG),age-related cataract and age-related macular degeneration ( AMD ).The antioxidative mechanism of GSTs to eye diseases is in study.The current researches about the element concept,distributions in eye tissues,gene polymorphism of GSTs and its relationship with eye oxidative damage were reviewed.

Diversidad e implicaciones de los polimorfismos de las enzimas glutatión S transferasas en la patogénesis del asma: [revisión] / Diversity and implications of glutathione S-trasferase enzymes polymorphisms in the pathogenesis of asthma: [review]

Las glutatión S-transferasas (GST) representan una superfamilia de enzimas presentes en todos los organismos aerobios. Existen tres familias principales que se encuentran ampliamente distribuidas en la naturaleza y se clasifican en citosólicas, mitocondriales y microsomales de acuerdo con su localización en la célula. Existen polimorfismos en los genes de estas enzimas los cuales se han encontrado asociados con enfermedades como el asma bajo los efectos de los contaminantes ambientales. La distribución de la frecuencia de estos polimorfismos varía en las distintas poblaciones y por ende la susceptibilidad de los individuos frente a las enfermedades relacionadas con ellos. Teniendo en cuenta la importancia de los polimorfismos en las GST y su relación con enfermedades de tipo respiratorio, se hace una revisión teórica actualizada acerca de las propiedades y funciones de estas enzimas, descripción de los polimorfismos genéticos y metodologías usadas para su genotipificación, así como la participación de los mismos en la patogénesis del asma.

The glutathione S-transferases (GST) represent a superfamily of enzymes present in all aerobic organisms. There are three main families that are widely distributed in nature and are classified into cytosolic glutathione s transferases, mitochondrial and microsomal according to their location in the cell. Polymorphisms reported in the genes encoding these enzymes have been associated with the onset of diseases such as asthma under the influence of environmental contaminants. The frequency distribution of these polymorphisms is different in the populations and therefore the susceptibility of individuals to the diseases associated with them. Given the importance of polymorphisms in GST and their relation with the respiratory diseases, we present a theoretical review updates on the properties and functions of glutathione S transferases, description of genetic polymorphisms and methodologies used for genotyping, as well as their participation in the pathogenesis of asthma.

Prognostic impact of GSTA1 polymorphisms on breast cancer patients treated with cyclophosphamide-based adjuvant chemotherapy / 中华检验医学杂志

Objective To investigate the association between the genetic polymorphisms in GSTA1 and the clinical outcome of breast cancer patients treated with cyclophosphamide-based adjuvant chemotherapy. Methods A total of 137 breast cancer patients receiving cyclophosphamide-based adjuvant chemotherapy were recruited ( 124 cases with infiltrative ductal carcinoma, 5 cases with infiltrative lobular carcinoma and 8 cases with other histological types). PCR-LDR method was used to detect the genotypes of GSTA1. Survival curves were generated by the Kaplan-Meier method, and verified by the log-rank test. Cox proportional hazards regression analysis was used to estimate the prognostic factors in multivariate analysis. Results Of the 137 breast cancer patients, the genotypic frequencies of the GSTA1 * A/* A,* A/* B and * B/* B were 67.2% ( 92/137 ), 31.4% ( 43/137 ) and 1.5% ( 2/137 ), respectively. No significant differences were found between the genotypic frequencies and groups categorization according to age, stage, lymph node metastasis, ER or PR status (x2 = 0. 722,1. 967, 3. 303, 0. 226 and 0. 709, all P ＞0. 05 ) ;through Fisher exact test, also no significant differences were found between the genotypic frequencies and group categorization according to tumor size, histological types and grading ( all P ＞ 0. 05 ) . The recurrence rates in patients with GSTA1 * A/* A and * A/* B or * B/* B genotypes were 47. 8% (44/92) and 31.1% ( 14/45 ), respectively, and the mortality rates were 22. 8% ( 21/92 ) and 17. 8% ( 8/45 ),respectively. Patients with GSTA1 * A/* B and * B/* B genotypes were significantly associated with reduced hazard of relapse (x2 =18.723, P＜0. 01)and mortality (x2 =7.352, P＜0.01), compared to cases with the common * A/* A genotypes, according to Kaplan-Meier survival analysis and log-rank test. Moreover,Cox multivariate analysis showed that GSTA1 polymorphisms appeared to be an independent risk factor for recurrence-free survival ( OR =0. 222, 95% CI:0. 108-0. 458, P ＜0. 01 ) and overall survival ( OR =0. 362,95% CI:0. 145-0. 902, P ＜ 0. 05 ). Conclusion These data indicate that GSTA1 polymorphism may be a potential prognostic factor for recurrence-free survival and overall survival in breast cancer patients treated with cyclophosphamide-based adjuvant chemotherapy.

Association of functionally important polymorphisms in cytochrome P450s with squamous cell carcinoma of head and neck.

Head and neck squamous cell carcinoma (HNSCC), a common malignancy that possibly involves a combination of exposure to the carcinogens and inherited genetic differences in the enzymes catalyzing their metabolism. Alcohol and tobacco consumption are the primary environmental risk factors, while polymorphism in various biotransformation enzymes such as cytochrome P450s (CYPs) and glutathione S-transferases, (GSTs) has been implicated as the major genetic risk factors for the development of HNSCC. The functionally important polymorphisms in these CYPs (1A1*2A, 1A1*2C, 1B1*2, 2E1*5B, 2E1*6, 2C19*2, 2D6*4, 2D6*10) and GSTs (GSTM1-null or GSTT1-null) were found to be significantly associated with HNSCC risk. Significant differences in the distribution of certain haplotypes of CYPs have also been reported and prevalence of certain genotype combinations of CYPs and GSTS in cases has indicated the importance of gene-gene interactions in HNSCC risk. Alcohol or tobacco use (smoking and chewing) were also found to interact synergistically with variant genotypes of these CYPs and GSTS in significantly enhancing HNSCC risk. This increase in risk associated with the variant genotypes with tobacco or alcohol use have further demonstrated the importance of gene–environment interactions in determining the susceptibility to HNSCC.

Melatonina, isoenzimas de glutationa S-transferases e estresse oxidante em pacu Piaractus mesopotamicus (Holmberg, 1887) / Melatonin, isoenzymes of glutathione S-transferases and oxidative stress in pacu Piaractus mesopotamicus (Holmberg, 1887)

O oxigênio é fundamental para os vertebrados. No entanto, variações dos níveis de oxigênio na água podem provocar estresse oxidante em peixes porque privação de oxigênio seguida de reoxigenação forma espécies reativas de oxigênio (ERO) em células. Níveis intracelulares de ERO aumentados favorecem que moléculas de proteínas, fosfolipídios e ácidos nucleicos sofram alterações, vindo a prejudicar muitas funções celulares. No Pantanal, habitat do pacu, o nível de oxigênio varia circadianamente na água das lagoas rasas que acabam isoladas dos rios na seca. O pacu evoluiu sob a pressão contínua da exposição aos efeitos prejudiciais das ERO causados pelos pulsos de inundação. A melatonina, uma indolamina produzida na glândula pineal, influencia os níveis de atividade de enzimas antioxidantes que reduzem ERO, além de ser capaz de doar elétrons ou captar radicais livres de forma não enzimática. Os níveis de melatonina no pacu são mais altos no verão e menores no inverno. Isoenzimas de glutationa S-transferases que conjugam o tripetídeo glutationa com o 4-hidroxinonenal, aldeído derivado da peroxidação de ácidos graxos por ERO, são importantes para evitar alteração funcional de proteínas por ligação do 4-hidroxinonenal à sua estrutura. Neste trabalho procuramos relação entre estresse oxidante, níveis de atividades de glutationa S-transferase e melatonina, para estabelecer se a melatonina ajudaria pacus a superar os efeitos deletérios das espécies reativas de oxigênio. Ensaiamos atividades de isoenzimas de glutationa S-transferases no citosol de fígado de pacus mantidos em normoxia, hipoxia, reoxigenação e hiperoxia no inverno e no verão. Medimos o efeito da malatonina in vitro e in vivo sobre as atividades de isoenzimas de glutationa S-transferase. Medimos os efeitos do estresse oxidante sobre a ligação do 4-hidroxinonenal com proteínas nos fígados de pacus tratados com melatonina. Somente as isoenzimas que conjugam 4-hidroxinonenal com glutationa...

Oxygen is vital for vertebrates. However, changes in the levels of dissolved oxygen in water might cause oxidative stress in fishes because the shortage of oxygen followed by reoxygenation originates reactive oxygen species (ROS) inside cells. Higher intracellular levels of ROS favor alterations of proteins, phospholipids and nucleic acid molecules, which result in impairment of many cell functions. In Pantanal, the pacu's habitat, circadian variation of the oxygen levels occurs in water of the shallow lagoons that ended up isolated from the rivers along the dry season. Pacu has evolved under the pressure of continuous exposition to harmful effects of ROS caused by the annual inundation pulses. Melatonin, an indolamine produced by the pineal gland, influences the levels of activity of antioxidant enzymes that reduce ROS, and is capable of donating electrons of scavenge free radicals non-enzymatically. Pacu's melatonin levels are higher during summer than in winter. Glutathione S-transferases isoenzymes that catalyze the conjugation of the tripeptide glutathione with 4-hydroxynonenal, an aldehyde derived from peroxidation of fat acids by ROS, are important to avoid functional alterations of proteins consequential to the binding of 4-hydroxynonenal to their structures. In the work, we searched for facts that linked oxidative stress, levels of activity of glutathione S-transferase and melatonin, in order to establish whether melatonin could help pacus to overcome the pernicious effects of reactive oxygen species. We carried out assays of glutathione S-transferases in liver cytosol of pacus kept under normoxia, hypoxia, reozygenation and hyperoxia, in the summer and in the winter. We measured the effect of melatonin in vitro and in vivo on isoenzymes of glutathione S-transferases. We measured the effects of oxidative stress on the binding of 4-hydroxynonenal to proteins in liver of pacu treated with melatonin. Only isoenzymes that conjugate 4-hydroxynonenal...

Cytochrome P450 (CYP) and glutathione S-transferases (GST) polymorphisms (CYP1A1, CYP1B1, GSTM1, GSTP1 and GSTT1) and urinary levels of 1-hydroxypyrene in Turkish coke oven workers

Genetic polymorphisms of xenobiotic metabolizing enzymes have been associated with cancer risk. We evaluated the influences of genetic polymorphisms of polycyclic aromatic hydrocarbon (PAH) metabolizing enzymes on urinary 1-hydroxypyrene (1-OHP) excretion in Turkish coke oven workers. Urinary 1-OHP was analyzed by HPLC after enzymatic hydrolysis. Lymphocyte DNA was used for PCR-based genotyping of cytochrome P450 (CYP) polymorphisms (CYP1A1 and CYP1B1) and glutathione S-transferases (GST) polymorphisms (GSTM1, GSTT1 and GSTP1). The mean urinary 1-OHP levels of coke oven workers were significantly higher than that of controls. No significant difference was detected in the mean urinary 1-OHP levels of smokers and non-smokers either for coke oven workers or controls. Genetic polymorphisms of the CYPs and GSTs studied had no significant influence on 1-OHP excretion in coke oven workers, but in the control group the urinary 1-OHP levels of individuals carrying the GSTT1- genotype were significantly higher than those of individuals carrying GSTT1+ genotype. The duration of occupational exposure and metabolic genotype for GSTT1 were the significant predictors of urinary 1-OHP levels. The control individuals carrying combined GSTM1-/GSTT1- genotypes also had significantly higher levels of urinary 1-OHP than those of individuals carrying GSTM1+/GSTTI+, GSTM1-/GSTT1+, and GSTM1+/GSTT1- genotypes. These results indicate that urinary 1-OHP is a sensitive indicator of recent human exposure to PAHs and that genetic polymorphism of GSTT1 may also to some extent reflect the interindividual variation in susceptibility to PAHs only at low PAH exposure.

Obtainment and Characterization of The Evolved Enzymes From Arabidopsis thaliana Glutathione S-Transferase Zeta Class / 生物化学与生物物理进展

The Arabidopsis thaliana glutathione S-transferases zeta class (AtGSTZ) is a multi-functional enzyme, which plays important role in cellular metabolism and environmental purification. Error-prone PCR and cycles of DNA shuffling were used to construct a mutagenesis library of AtGSTZ. The screening of the resultant libraries was carried out by a pH indicator dye-based colorimetric assay. Nine mutants which enhanced the dichloroacetic acid dechlorination activity were obtained. Among them, NN23 contained 25 amino acid substitutions with the activity improving 120%, whereas NN20 contained 24 amino acid substitutions with the activity improving 102%. EC1 contained 2 amino acid substitutions with the activity improving 47%. The rest 6 mutants contained one amino acid substitution with their activity increasing from 9% to 60%. The enzymatic characterization showed that all the evolved enzymes increased their catalytic efficiencies towards dichloroacetic acid and binding affinity towards glutathione whereas some of them increased the renaturability. However there is no obvious change in their thermostability. Based on these data, functional residues related to catalysis and refolding of AtGSTZ were discussed.