EffectofGSTP1geneticvariationontherecurrenceriskandprognosisofcolorectal cancerpatients received postoperative adjuvant chemotherapy / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To investigate the influence of glutathione S-transferase P-1 (GSTP1) genetic variation on the recurrence risk and prognosis of colorectal cancer (CRC) patients received postoperative adjuvant chemotherapy. Methods: The clinical data of 195 CRC patients, who received postoperative adjuvant chemotherapy in the Department of Gastroenterology of the FirstAffiliated Hospital of Zhengzhou University from January 2010 to December 2018, were collected for this study. 5-fluorouracil (5-FU) based adjuvant chemotherapy was given after surgical resection. The recurrence status of the patients was assessed during hospitalization period, and the long-term survival data of patients were obtained by telephone follow-up after finishing the scheduled adjuvant chemotherapy. GSTP1 genotyping was performed with the DNA extracted from peripheral blood specimens, and its correlation with patients’clinical characteristics wasanalyzed.Additionally, RNAwasextractedfrom peripheral blood mononuclear cell (PBMC) specimens of some CRC patients that prior to chemotherapy for GSTP1 mRNA expression analysis. The univariate analysis of genotypes and prognosis was carried out by Kaplan-Meier survival analysis, and adjusted by multivariate Cox regression model. Results: The median disease-free survival (DFS) of the 195 CRC patients was 4.8 years, and the median overall survival (OS) was 6.2 years. Polymorphism analysis indicated that the I105VlocusofGSTP-1coding region was correlated with prognosis. The prevalence of I105V in the study population: AA genotype of 135 cases (69.23%), AG genotype of 56 cases (28.72%) and GG genotype of 4 cases (2.05%), the minor allele frequency of I105V was 0.16. The genotype distribution was in accordance with Hardy-Weinberg equilibrium (P>0.05). The analysis of recurrence risk and prognosis found that the median DFS of patients with AA genotype and AG/GG genotype was 5.7 and 3.9 years respectively (P<0.01), while the median OS of two groups of patients was 7.0 and 4.5 years respectively (P<0.01). The multivariate Cox regression results indicated that AG/GG genotype was an independent factor for OS (OR=1.54, P<0.05). The mRNA expression of GSTP1 in PBMC of the patients with AG/GG genotypes were significantly higher than those patients with AA genotype (P<0.01). Conclusion: GSTP1 I105V genetic variation influences the recurrence risk and prognosis of CRC patients received postoperative adjuvant chemotherapy possibly via mediating the mRNAexpression of GSTP1.

Correlation of GSTP1 Polymorphism with Severity of Prostate Cancer in an Eastern Indian Population

Background:GSTP1is one of the Glutathione-S-Transferases(GSTs) which suppress tumor genesis by detoxifying toxic carcinogens and reactive oxygen species (ROS). Prostate cancer is related to several mutations affecting the expression of GSTP1. A single nucleotide polymorphism (SNP: Ile105Val) in the GSTP1gene results insignificant reduction in its anticancer activity. The current case control study was conducted to ascertain the risk of association of GSTP1polymorphism with risk of cancer prostate in an Eastern Indian population. Materials and Methods: During a study period of 2 years, DNA was isolated using the phenol chloroform extraction method from the blood of 225 histopathologically diagnosed prostate cancer patients and 120 matched controls. The GSTP1polymorphism was assessed by PCR amplification of thegene followed by restriction digestion with Alw261 (a restriction enzyme derived from Acinetobactro lwoffiRFL26). Histopathological grading in the case group was performed using Gleason’s scores and International Society of Urological Pathology (ISUP) grading. Results:Comparison of the distribution of different GSTP1alleles between the case and control groups was performed by chi square test and odds ratio analysis. A χ2 value of 18.56 suggested significantly higher number of Galleles in the case group. An odds ratio of 2.25 with a confidence interval of 1.52 to 3.34 for 95% CI showed that the Gallele in GSTP1gene were linked with greater risk of prostate cancer. Post hoc ANOVA and logistic regression suggested that cases having Galleles had more progressive form of diseases as evident from ISUP grades.Conclusion:From our study we can conclude that GSTP1polymorphism is not only significantly associated with risk of prostate cancer but also with its severity in our Eastern Indian population.GSTP1polymorphism should be considered as a prognostic indicator for prostate cancer patients along with planning for more aggressive management of the disease

Study on the Relationship of GSTP1(rs1695)Genetic Polymorphism with Hematological Toxicity of Autologous Hematopoietic Stem Cell Transplantation Patients / 中国药房

OBJECTIVE:To study the relationship of GSTP 1(rs1695)(simply as GSTP 1)gene polymorphism with the hematological toxicity in autologous hematopoietic stem cell transplantation(AHSCT)patients who used CBV regimen (cyclophosphamide,carmustine,etoposide). METHODS:A total of 83 AHSCT patients receiving CBV regimen were retrospective analyzed in our hospital during Apr. 2015-Jun. 2017. The gene polymorphism of GSTP 1 A313G was detected by fluorescence staining in situ hybridization. The hematological toxicity and the incidence of agranulocytosis fever,the implantation time of leukocyte,neutrophils and platelet were analyzed statistically. The relationship of GSTP 1 with above indexes were analyzed. RESULTS:Among 83 patients,gene variation was observed in one gene loci at least of 28 patients(33.73%).The gene frequency of A allele was 81.3%,while that of G allele was 18.7%. The reduce time of Ⅳ grade leukopenia,Ⅳ grade neutropenia and Ⅳgrade thrombocytopenia in GSTP 1 AA genotype patients were(8.91 ± 1.25),(9.02 ± 1.19),(11.56 ± 1.58)d after chemotherapy;those of patients with GSTP 1 313 allele G(AG/GG genotype) were(8.61 ± 1.17),(8.68 ± 1.19),(11.44 ± 1.34)d after chemotherapy. The implantation time of leukocyte,neutrophils and platelet in patients with GSTP 1 AA genotype were(11.98±1.99),(10.44±1.35),(15.55±2.18)d after autologus peripheral blood stem cell reinfusion;those of patients with GSTP1 313 allele G(AG/GG genotype)were(12.41±2.44),(10.36±1.62),(16.29±3.15)d after autologus peripheral blood stem cell reinfusion. The case number of grade Ⅲ-Ⅳ anemia were 24 and 11,accounting for 43.64% and 39.29% of corresponding genotype patients. The case number of agranulocytosis fever in patients with GSTP 1 AA genotype or GSTP 1 313 allele G(AG/GG genotype)were 21 and 11 during transplantation,accounting for 38.18% and 39.29% of corresponding genotype patients, respectively,without statistical significantly(P>0.05). CONCLUSIONS:There is no relationship between GSTP 1 gene polymorphism and hematological toxicity of AHSCT patients receiving CBV regimen.

Interactions Between Bisphenol A Exposure and GSTP1 Polymorphisms in Childhood Asthma

PURPOSE: Bisphenol A (BPA) exposure may increase the risk of asthma. Genetic polymorphisms of oxidative stress-related genes, glutathione S-transferases (GSTM1, GSTP1), manganese superoxide dismutase, catalase, myeloperoxidase, and microsomal epoxide hydrolase may be related to BPA exposure. The aim is to evaluate whether oxidative stress genes modulates associations of BPA exposure with asthma. METHODS: We conducted a case-control study comprised of 126 asthmatic children and 327 controls. Urine Bisphenol A glucuronide (BPAG) levels were measured by ultra-performance liquid chromatography/tandem mass spectrometry, and genetic variants were analyzed by a TaqMan assay. Information on asthma and environmental exposure was collected. Analyses of variance and logistic regressions were performed to determine the association of genotypes and urine BPAG levels with asthma. RESULTS: BPAG levels were significantly associated with asthma (adjusted odds ratio [aOR], 1.29 per log unit increase in concentration; 95% confidence interval [CI], 1.081.55). Compared to the GG genotype, children with a GSTP1 AA genotype had higher urine BPAG concentrations (geometric mean [standard error], 12.72 [4.16] vs 11.42 [2.82]; P=0.036). In children with high BPAG, the GSTP1 AA genotype was related to a higher odds of asthma than the GG genotype (aOR, 4.84; 95% CI, 1.0223.06). CONCLUSIONS: GSTP1 variants are associated with urine BPA metabolite levels. Oxidative stress genes may modulate the effect of BPA exposure on asthma.

Methylation of GSTP1 promoter region in hepatocellular injury induced by isoniazid / 国际药学研究杂志

Objective To investigate the relationship between methylation of CpG island in glutathione S-transferase P1(GSTP1) promoter region and injury induced by isoniazid in HL-7702 cells.Methods HL-7702 cells were divided into the control group and three isoniazid groups(200,400,800 mg/L).Colorimetric method was used to detect the activity level of lactate dehydrogenase in the medium of HL-7702 cells;the mRNA expression of GSTP1,DNA methyltransferases 1(DNMT1),DNMT3a and DNMT3b were de?tected by real-time fluorescence quantitative PCR;the protein expression levels of DNMT1,DNMT3a and DNMT3b were detected by enzyme-linked immunosorbent assay;the methylation of the CpG island in the GSTP1 promoter region was determined by the bisulfite sequencing PCR.Results The activity level of lactate dehydrogenase in supernatants of the HL-7702 cells in isoniazid group(400, 800 mg/L)was higher than that in the control group(P<0.01).Compared with the control group,the mRNA expression of DNMT 1、3a、3b and GSTP1 were elevated in 400 and 800 mg/L isoniazid groups(P<0.05,P<0.01).The proteins expression of DNMT1 and 3a in the 400 and 800 mg/L isoniazid groups were higher than that in the control group(P<0.05,P<0.01),and the protein expression of DNMT 3b in the 800 mg/L isoniazid groups were higher than that in the control group(P<0.01).The methylation level of CpG is?land in GSTP1 promoter region of three isoniazid groups were decreased.Conclusion The CpG island in the promoter of GSTP1 has hypomethylation in hepatocyte cells damaged by isoniazid.

Over-expression of GSTP1 increases oxaliplatin-induced apoptosis in hu-man hepatoma HepG2 cells / 中国病理生理杂志

AIM: To investigate the effect of GSTP1 over-expression on the sensitivity of human hepatoma HepG2 cells to oxaliplatin (OXA).METHODS: Adenovirus carrying GSTP1 (Ad-GSTP1) was used to infect HepG2 cells for establishing the cell line over-expressing GSTP1.The cells were randomly divided into 6 groups: control, vehicle, Ad-GSTP1, OXA, OXA +vehicle and OXA +Ad-GSTP1.The cell survival rates were examined by CCK-8 assay, and the apoptotic rates were analyzed by flow cytometry.The protein levels of GSTP1, Akt, mTOR, p-Akt and p-mTOR were deter-mined by Western blot.RESULTS: OXA decreased the cell survival rate in a dose-dependent manner (P <0.05).The protein expression of GSTP1 increased after transfection with adenovirus.At basal level, up-regulation of GSTP1 signifi-cantly decreased the cell survival rate, increased the cell apoptosis, and inhibited the phosphorylation levels of Akt and mTOR (P <0.05).Moreover, GSTP1 over-expression enhanced the effect of OXA on the cell viability, cell apoptosis, and further inhibited the phosphorylation levels of Akt and mTOR ( P <0.05).CONCLUSION: Over-expression of GSTP1 augments the enhanced effect of OXA on HepG2 cell apoptosis, which may be related to the inactivation of Akt/mTOR signaling pathway.

Relationship between FOLFOX Chemotherapy of Colorectal Cancer Patients and GSTP1,XRCC1 Gene Polymorphism / 现代检验医学杂志

Objective To explore the relationship between FOLFOX Chemotherapy and GSTP1,XRCC1 gene polymorphism in patients with colorectal cancer.Methods 60 cases of colorectal cancer treated in Tumor hospital of Hunan Province from January to December 2014 were selected as the research object.Treat patients with modified FOLFOX regimen,determined the GSTP1 ,XRCC1 gene sequence polymorphism,and explored the relationship between the efficacy and the GSTP1 ,XRCC1 gene sequence polymorphism.Results The number of patients with complete remission and partial remission and the num-ber of patients with stable and progress were not related to the gender,age,tumor location,pathological differentiation,TNM staging of patients (χ2=0.222~1.8,P>0.05).Of all cases,the frequencies of GSTP1A/A,A/G and G/G genotype were 68.3%,23.3% and 8.3%,respectively.GSTP1 gene wild-type (A/A)patients were treated with less efficiency than the GSTP1 gene mutation type (A/G+G/G)patients (χ2=4.493,P=0.034).Of all cases,the frequencies of XRCC1 G/G,G/A and A/A genotype were 58.3%,36.7% and 5%,respectively.XRCC1 gene wild type (G/G)patients with effective rate was higher than that of mutant type (G/A+A/A)patients (χ2=4.691,P=0.030).Conclusion The study showed that GSTP1(A/A),XRCC1 (G/G)gene polymorphism may be associated with clinical response to FOLFOX chemotherapy in advanced colorectal cancer.

Unraveling Brazilian Indian population prostate good health: clinical, anthropometric and genetic features

Purpose To compare dietary, lifestyle, clinical, anthropometric, genetic and prostatic features of Brazilian Indians and non-Indians (Amazon). Methods 315 men, 228 Indians and 89 non-Indians, ≥40 years old were submitted to digital rectal examination, serum prostate specific antigen (PSA), testosterone, TP53 and GSTP1 genotyping, anthropometric, lifestyle, dietary, personal and familial medical history. Prostatic symptoms were evaluated with the International Prostate Symptom Score (IPSS). Results Macuxis and Yanomamis represented 43.6% and 14.5% of Indians respectively who spontaneously referred no prostate symptoms. Mean IPSS was 7, range 3-19, with only 15% of moderate symptoms (score 8-19); Mean age was 54.7 years, waist circumference 86.6 cm, BMI 23.9 kg/m2. Yanomamis presented both lower BMI (21.4 versus 24.8 and 23.3, p=0,001) and prostate volume than Macuxis and “other ethnic groups” (15 versus 20, p=0.001). Testosterone (414 versus 502 and 512, p=0.207) and PSA (0.48 versus 0.6 and 0.41, p=0.349) were similar with progressive PSA increase with aging. Val/Val correlated with lower PSA (p=0.0361). Indians compared to control population presented: - TP53 super representation of Arg/Arg haplotype, 74.5% versus 42.5%, p<0.0001. -GSTP1 Ile/Ile 35.3% versus 60.9%; Ile/Val 45.9% versus 28.7%; Val/Val 18.8% versus 10.3%; p=0.0003. Conclusions Observed specific dietary, lifestyle, anthropometric and genetic profile for TP53 and GSTP1 may contribute to Brazilian Indian population prostate good health. .

GSTM1, GSTT1, and GSTP1 polymorphisms, breast cancer risk factors and mammographic density in women submitted to breast cancer screening / Polimorfismos GSTM1, GSTT1 e GSTP1, fatores de risco para câncer de mama e densidade mamográfica em mulheres submetidas a rastreamento mamográfico

Genetic polymorphisms in genes related to the metabolism of xenobiotics, such as genes of the glutathione S-transferases (GSTM1, GSTT1, and GSTP1) superfamily have been associated with an increased risk for breast cancer (BC). Considering the high incidence of BC in the city of Porto Alegre in southern Brazil, the purpose of this study was to characterize genotypic and allelic frequencies of polymorphisms in GSTM1, GSTT1, and GSTP1, and correlate these molecular findings with established risk factors for breast cancer including mammographic density, in a sample of 750 asymptomatic women undergoing mammographic screening. Molecular tests were performed using the multiplex polymerase chain reaction (PCR) for GSTM1 and GSTT1, and quantitative PCR for GSTP1 polymorphisms. Overall, the frequencies of GSTM1 and GSTT1 null genotypes were 45% and 21%, respectively. For GSTP1 polymorphism, genotypic frequencies were 44% for the Ile/Ile genotype, 44% for the Ile/Val genotype, and 12% for Val/Val genotype, with an allelic frequency of 66% for the wild type allele in this population, similar to results of previous international publications. There was a statistically significant association between the combined GSTM1 and GSTT1 null genotypes (M-/T-) and mammographic density in post menopausal women (p = 0.031). When the GSTT1 null (T-) genotype was analyzed isolated, the association with mammographic density in post menopausal women and in the overall sample was also statistically significant (p = 0.023 and p = 0.027, respectively). These findings suggest an association of GSTM1 and GSTT1 null genotypes with mammographic density.

Polimorfismos genéticos em genes relacionados com o metabolismo de xenobióticos, como os genes da superfamília das glutationa S-transferases (GSTM1, GSTT1 e GSTP1) têm sido associados com o aumento do risco para câncer de mama (CM). Considerando a alta incidência de CM na cidade de Porto Alegre, região Sul do Brasil, a proposta deste estudo foi caracterizar genótipos e frequências alélicas dos polimorfismos GSTM1, GSTT1 e GSTP1, e correlacionar esses achados moleculares com fatores de risco já estabelecidos para câncer de mama, incluindo densidade mamográfica, em uma amostra de 750 mulheres assintomáticas durante o rastreamento mamográfico. Para os testes moleculares foi utilizado multiplex da reação em cadeia de polimerase (PCR) para GSTM1 e GSTT1, e PCR quantitativo para o polimorfismo GSTP1. As frequências dos genótipos GSTM1 e GSTT1 nulos foram 45% e 21%, respectivamente. Para o polimorfismo GSTP1, as frequências genotipicas foram: 44% para o genótipo Ile/Ile, 44% para o genótipo Ile/Val e 12% para o genótipo Val/Val. A frequência do alelo lle nesta população foi 66%, semelhante a outros estudos. Houve uma associação significativa entre a combinação dos genótipos (T-/M-) nulos e densidade mamográfica nas mulheres pós-menopáusicas (p = 0,031). Quando analisamos isoladamente o genótipo GSTT1 nulo (T-) também encontramos uma associação significativa com a densidade mamográfica nas mulheres pós-menopáusicas (p = 0,027) e na amostra total. Estes achados sugerem uma associação dos genótipos (T-/M-) nulos com densidade mamográfica.

Study on the polymorphisms of CYP3A5 and GSTP1 genes in the prediction of short-term efficacy of docetaxel plus thiotepa for patients with metastatic breast cancer / 中国药学杂志

OBJECTIVE: To investigate whether the polymorphisms of cytochrome P450 3A5 (CYP3A5) gene and glutathione S-transferase P1 (GSTP1) gene are associated with the short-term efficacy of docetaxel plus thiotepa for Chinese patients with metastatic breast cancer. METHODS: All patients received docetaxel plus thiotepa chemotherapy. CYP3A5 and GSTP1 were genotyped by matrix assisted laser desorption ionization / time of flight (MALDI-TOF). Disease control rate (DCR) was evaluated every two chemotherapy cycles, and was compared between different genotypes. RESULTS: Among 93 enrolled patients, people with CYP3A5 A6986G GG genotype showed a statistically higher DCR than those with AG + GG genotype (77.8% versus 57.4%, P < 0.05), and the DCR of the patients with GSTP1 A313G AG + GG was statistically higher than that of patients with AA (81.6% versus 57.4%, P < 0.05). Combination analysis showed that patients with GSTP1 A313G AG + GG and CYP3A5 A6986G GG had the highest DCR (84.2%, P < 0.05). CONCLUSION: CYP3A5 and GSTP1 polymorphisms are associated with the short-term efficacy of docetaxel plus thiotepa. Higher DCRs were seen in patients carrying GSTP1 A313G AG + GG and / or CYP3A5 A6986G GG genotype, which might be a reference for clinical chemotherapy. Copyright 2012 by the Chinese Pharmaceutical Association.

DNA Methylation of GSTP1 in Human Prostate Tissues: Pyrosequencing Analysis

PURPOSE: DNA methylation is an important epigenetic mechanism of gene regulation and plays essential roles in tumor initiation and progression. Differences in methylation patterns between neoplastic and normal cells can be used to detect the presence of cancer. The aim of the present study was to evaluate the usefulness of glutathione-S-transferase-Pi (GSTP1) hypermethylation in discriminating between normal and prostate cancer (PCa) cells and in predicting tumor characteristics by use of quantitative pyrosequencing analysis. MATERIALS AND METHODS: A total of 100 human prostate tissues obtained from our institute were used in this study: 45 for benign prostatic hyperplasia (BPH) and 55 for PCa. The methylation level of GSTP1 was examined by a quantitative pyrosequencing analysis. The associations between GSTP1 methylation level and clinico-pathological parameter were also compared. RESULTS: The level of GSTP1 methylation was significantly higher in PCa samples than in BPH samples (56.7+/-32.7% vs. 1.6+/-2.2%, p<0.001). The sensitivity and specificity of GSTP1 methylation status in discriminating between PCa and BPH reached 85.5% and 100%, respectively. Even after stratification by stage, Gleason score, and prostate-specific antigen (PSA) level, similar results were obtained. A positive correlation between GSTP1 methylation level and serum PSA level was observed (r=0.303, p=0.002). There were no associations between GSTP1 methylation level and age, Gleason score, and staging. CONCLUSIONS: Our study demonstrates that GSTP1 methylation is associated with the presence of PCa and PSA levels. This methylation marker is a potentially useful indicator for the detection and monitoring of PCa.

Óxido nítrico, GSTP-1 e p53: qual o papel desses biomarcadores nas lesões prostáticas do cão? / Nitric oxide, GSTP-1 and p53: what's the role of these biomarkers in dog´s prostate lesions?

Confeccionou-se um microarranjo de tecido (TMA) com 146 amostras de lesões prostáticas caninas. Este continha 17,2 por cento de hiperplasia prostática benigna (HPB), 32,4 por cento de atrofia inflamatória proliferativa (PIA), 2,6 por cento de prostatite, 8,6 por cento de focos de neoplasia intraepitelial prostática (PIN), 29,1 por cento de carcinomas e 9,3 por cento de próstatas normais. Cortes histológicos sequenciais foram feitos e utilizados para reação de imunoistoquímica com os anticorpos primários anti-p-53, anti-NOS-2 e anti-GSTP. Avaliou-se de cada core o escore de células marcadas para cada anticorpo utilizado. Os resultados foram tabulados por grupo diagnóstico e submetidos ao teste Tuckey. Os carcinomas prostáticos do cão e a PIA apresentaram maior número de amostras (41) com mais de 75 por cento das células positivas para NOS-2, demonstrando a influência do estresse oxidativo no desenvolvimento dessas lesões. As próstatas normais e as afecções desta glândula, HPB, PIA, PIN, prostatite e carcinoma, expressaram a proteína GSTP-1, o que conferiu proteção ao tecido prostático canino a danos oxidativos. A proteína p53 estava presente em todas as amostras estudadas, incluindo o tecido prostático normal, porém as lesões prostáticas apresentaram maior número de amostras com escores mais elevados de marcação (escores três e quatro), presente em 95 por cento dos focos de PIA e carcinoma. Concluiu-se que o aumento de expressão de óxido nítrico nas lesões prostáticas no cão e a expressão de GSTP-1 podem ter protegido o tecido prostático canino e que a expressão de p53 foi positiva e uniforme nas próstatas normais e com lesões hiperplásicas e displásicas.

A tissue microarray (TMA) with 149 samples of canine prostatic lesions contained 17.2 percent benign prostatic hyperplasia (BPH), 32.4 percent proliferative inflammatory atrophy (PIA), 2.6 percent prostatitis, 8.6 percent foci prostatic intraepithelial neoplasia (PIN), 29.1 percent carcinomas and 9.3 percent normal prostates. Sequential histological sections were made and used for immunohistochemistry reaction with primary antibodies anti p-53, anti-NOS-2 and anti-GSTP. The score for each antibody employed was evaluated. The results were tabulated by diagnostic group and subjected to Tuckey test. Prostatic carcinomas and PIA had a higher number of samples (41) with over 75 percent of cells positive for NOS-2, demonstrating the influence of oxidative stress in the development of these lesions. The prostates of normal dogs, as well as the disorders of this gland (BPH, PIA, PIN, prostatitis and carcinoma), expressed GSTP-1 protein, which gives protection to the canine prostate tissue against oxidative damage. The p53 protein was present in all samples studied, including normal prostate tissue, but the prostatic lesions had a higher number of samples with higher scores (more than 50 percent of positive cells), in 95 percent of foci of PIA and carcinoma. It was found that an increased expression of NO in prostatic lesions of dogs and that the expression of GSTP-1 can protect the canine prostate tissue, which would contribute to the low frequency of prostate adenocarcinoma in this species. The expression of p53 was positive in all lesions as well as the in normal prostate.

Mutational analysis of xenobiotic metabolizing genes (CYP1A1 and GSTP1) in sporadic head and neck cancer patients

CYP1A1 is the phase I enzyme that detoxifies the carcinogen or converts it into a more electrophilic form, metabolized by phase II enzymes like GSTP1. These detoxifying genes have been extensively studied in association with head and neck cancer (HNC) in different ethnic groups worldwide. The current study was aimed at screening genetic polymorphisms of genes CYP1A1 and GSTP1 in 388 Pakistani HNC patients and 150 cancer-free healthy controls, using PCR-SSCP. No already known variants of either gene were found, however a novel frameshift mutation due to insertion of T (g.2842_2843insT) was observed in the CYP1A1 gene. A statistically significant number (5.4 percent) of HNC cases, with the mean age of 51.75 (±15.7) years, presented this frameshift mutation in the conserved domain of CYP1A1. Another novel substitution mutation in was found in the GSTP1 gene, presenting TA instead of AG. The g.2848A > T polymorphism causes a leucine-to-leucine formation, whereas g.2849G > A causes alanine-to-threonine formation at amino acid positions 166 and 167, respectively. These exonic mutations were found in 9.5 percent of the HNC patients and in none of the controls. In addition, two intronic deletions of C (g.1074delC and g.1466delC) were also found in 11 patients with a mean age of 46.2 (±15.6) years. In conclusion, accumulation of mutations in genes CYP1A1 and GSTP1 appears to be associated with increased risk of developing HNC, suggesting that mutations in these genes may play a role in the etiology of head and neck cancer.

Cáncer gástrico y genes detoxificadores en una población colombiana / Gastric cancer and detoxifying genes in a colombian population

El objetivo fue establecer si hay asociación entre el cáncer gástrico (CG) y los polimorfismos desfavorables de los genes desintoxicadores GSTM1, GSTP1 y GSTT1. A la vez, se exploró si el hábito del tabaquismo, el consumo de alcohol y el nivel socioeconómico también interactúan como factores de riesgo en una población colombiana con alta incidencia de CG. Participaron 87 pacientes afectados por CG e igual número de controles del mismo grupo poblacional del departamento de Caldas. Todos fueron genotipíficados por medio de PCR para los polimorfismos GSTM1-nulo, GSTP1-val y GSTT1-nulo. Se colectó información acerca del tabaquismo, consumo de alcohol y nivel socioeconómico. Los resultados encontrados sugieren que es factor de riesgo significativo portar el genotipo GSTT1-nulo o el alelo GSTP1-val y pertenecer a los niveles socioeconómicos bajo o medio. También se detectó un interacción significativa entre el tabaquismo, el nivel socioeconómico bajo y el riesgo a CG. En conclusión, se evidencia interacción significativa entre ambiente-gen, particularmente entre el genotipo GSTT1-nulo, el alelo GSTP1-val, el nivel socioeconómico bajo, el tabaquismo y el riesgo a desarrollar CG en la población de esta región colombiana.

The objective was to establish whether there are associations between gastric cancer (GC) and unfavorable polymorphisms in GSTM1, GSTP1 and GSTT1 detoxifying genes. Simultaneously interactions of smoking habits, alcohol consumption and socioeconomic levels were investigated as possible risk factors in a Colombian population with a high incidence of GC. 87 patients affected by GC and 87 controls from the same population group in the Department of Caldas participated in the research. All patients were genotyped by PCR for GSTM1-null, GSTP1-val and GSTT1-null polymorphisms. Information about tobacco smoking, alcohol consumption and socioeconomic levels was collected. Results suggest that the GSTM1-nul genotype and GSTP1-val allele are significant risk factors as are low and medium socioeconomic levels. Significant interaction between tobacco smoking, low socioeconomic levels and GC risks were also detected. To conclude, there is significant interaction between environment and genes, particularly between the GSTT1-nulle genotype and GSTP1-val allele and low socioeconomic levels, tobacco smoking and the risk of GC development within this Colombian region’s population.

Effects of 5-aza-2′-deoxycitydine on proliferation of prostate cancer cell line PC3 and transcriptional regulation of tumor suppressor gene GSTP1 and RASSF1A / 第二军医大学学报

Objective: To observe the effects of 5-aza-2′-deoxycitydine (5-aza CdR) on the proliferation and transcription of tumor suppressor gene GSTP1 and RASSF1A in prostate cancer cell line PC3. Methods: The status of 5′CpG island methylation of RASSF1A and GSTP1 genes in PC3 was analyzed by methylation specific PCR (MSP) before treatment with 5-aza CdR. RASSF1A and GSTP1 mRNA were quantified by real time PCR during the demethylation process by 5-aza-CdR. MTT assay and flow cytometry were used to examine the proliferative activity of PC3 cells before and after 5-aza-CdR treatment. Results: The 5′ CpG island methylation of RASSF1A and GSTP1 genes were detected in human prostate cancer cell line PC3. Compared with control group, RASSF1A and GSTP1 mRNA expression had no significant change 24 h after culture with 5-aza-CdR; their expression was up-regulated 48 h after cultured with 5-aza-CdR, with significant difference found between 5 μmol/L and 10 μmol/L 5-aza-CdR groups. Compared with control group, the expression of RASSF1A and GSTP1 mRNA was significantly increased 72 h after cultured with all concentrations of 5-aza-CdR. MTT assay and cell cycle examination indicated that exposure to 5-aza-CdR for 24 h and 48 h resulted in no obvious growth inhibition and cell cycle change; exposure to 5-aza-CdR for 72 h induced significant growth inhibition (P<0.05) and cell cycle change (P<0.05); and cells were arrested at G0/ G1, phase. Conclusion: The 5′CpG island methylation of RASSF1A and GSTP1 genes is probably responsible for RASSF1A and GSTP1 silencing in PC3 cells. 5-aza-CdR can inhibit the proliferation of PC3 cells, disturb the cell cycle, and elevate transcription of GSTP1 and RASSF1A.

Relationship of GSTP1, RASSF1A polymorphisms and environmental agent with susceptibility to prostate cancer: A case-control study / 第二军医大学学报

Objective: To investigate relationship of GSTP1, RASSF1A polymorphisms and environmental agent with susceptibility to prostate cancer (Pca). Methods: The GSTP1 and RASSF1A genotypes were determined by TaqMan/MGB Probe Technology in 103 patients with Pca and 103 normal controls. Multivariate logistic regression model was used to assess the association of smoking, alcohol drinking, tea drinking, weekly pork and beef consumption, and the genetic polymorphisms with the susceptibility to Pca, while taking into consideration of the environmental agent. Results: The frequencies of the GSTP1 AA, AG and GG genotypes were 66.02%, 22.33%, and 11.65% in patients with Pca and 67.96%, 29.13% and 2.91% in controls, respectively, with significant difference found between the two groups (X2 = 6.35, P = 0.04). The frequencies of RASSF1A CC, CA and AA genotypes were 88.34%, 5.83%, and 5.83% in patients with Pca, and 85.44%, 12.62%, and 1.94% in the controls, respectively, with no significant difference found between the two groups (X2 = 4.63, P = 0.10). Multivariate analysis showed a decreased risk in those who had a tea drinking history (OR = 0.40, 95% CI, 0.19-0. 82) and an increased risk in those who had a smoking history (OR = 3.02, 95% CI, 1.44-6. 32). Conclusion: Our results indicate that GSTP1, RASSF1A polymorphisms are not associated with Pca susceptibility in Chinese Han nationality. Smoking is the risk factor of Pca, and tea drinking is a protective factor against Pca.

Determinação do polimorfismo da enzima GSTP1 em trabalhadores expostos à sílica e associação com silicose / Determination of enzyme GSTP1 polymorphism in workers exposed to silica and association with silicosis

A sílica é um composto natural formado pelos dois elementos mais abundantes na Terra - oxigênio e silício. A exposição a partículas de sílica cristalina induz a uma inflamação pulmonar crônica, que pode evoluir para fibrose pulmonar, acarretando na doença conhecida como silicose. O estresse oxidativo desempenha um papel importante na patogênese desta fibrose pulmonar.Sendo assim, a expressão de genes antioxidantes, como glutationa S-transferases (GSTs), são importantes componentes de proteção das células contra o estresse oxidativo e são conhecidas como genes altamente polimórficos, podendo contribuir para a susceptibilidade a silicose. Opolimorfismo da GSTP1 A/G resulta na substituição do aminoácido isoleucina por valina, diminuindo, substancialmente, a atividade da enzima GSTP1. O estudo teve como objetivo adeterminação do polimorfismo da enzima GSTP1 em trabalhadores expostos à sílica e associaçãocom silicose. A população foi composta por 82 trabalhadores expostos à sílica oriundos, principalmente, da indústria naval. O polimorfismo da GSTP1 foi analisado por PCR-RFLP. Como resultado verificou-se que 31,6 por cento dos trabalhadores tinham genótipo A/A, 57,9 por cento A/G e 10,5 por cento G/G. Observou-se que a média da atividade enzimática da GST foi menor (1,58 U/mL enzima) em indivíduos com o alelo G em relação ao alelo A (1,84 U/mL de enzima)...

Chemotherapeutic Responsibility according to Polymorphism of ERCC1, XRCC1 and GSTP1 in Gastric Cancer Patients Receiving Oxaliplatin Based Chemotherapy

PURPOSE: The platinum-based modified FOLFOX-6 has been reported as an acceptable chemotherapeutic regimen in treatment of advanced gastric cancer patients. The response rate and drug-induced toxicity of platinum-based chemoagents is different according to several gene polymorphism such as ERCC1, XRCC1 and GSTP1 genes, which were related with therapeutic mechanisms. We aimed to evaluate the effect of gene polymorphism and determine the possibility as prediction factor for responsibility in advanced and recurrent gastric cancer patients treated with modified FOLFOX-6 regimen. METHODS: This study was conducted with 55 patients. We sampled 20 ml of peripheral blood to isolate DNA from lymphocytes, and identified genotypes of 3 genes (ERCC1, XRCC1, GSTP1) by PCR-RFL of extracted DNA. Based on medical records, retrospective analysis was made on the patients' clinical characteristics. RESULTS: The overall response rate to modified FOLFOX-6 was 40.0% (22/55). In polymorphism of ERCC1 C8092A, the wild type (CC) showed a statistically significantly lower response rates to chemoagents than the mutant type (CA/AA). In the subtypes of ERCC1 C118T, however, the wild type (CC) showed statistically significantly lower hematological toxicity than the mutant type (CA/AA). But, there was no statistically significance in survival analysis. CONCLUSION: We suggest that ERCC1 gene polymorphism is clinically more adequate as a feasible factor for predicting the response rate and toxicity of modified FOLFOX-6 regimen in gastric cancer patients.

Study of genetic polymorphism in solvent exposed population and its correlation to in vitro effect of trichloroethylene on lymphocytes.

Trichloroethylene (TCE) is major industrial pollutant that contaminate environment. Its exposure may lead to hepato-renal toxicity along with the cancer progression. Although extensive research is done on its toxicity, still not much is known about its genotoxic potential on humans in relation to genetic polymorphism. Cytochrome P450 (CYP P-450) and glutathione-S-transferases (GSTs) are important in cellular detoxification of TCE. Variations in gene sequences result in population specific regional genetic variations (polymorphism). Genotyping of CYP1A1, GSTM1, GSTT1 and GSTP1 polymorphism was performed in 220 normal and 97 solvent-exposed individuals from northern part of India using real time PCR, PCR and restriction digestion techniques. The parameters examined to study genotoxicity were chromosomal aberration (CA) and cytokinesis block micronucleus assay (CBMN) in lymphocyte culture in vitro. The observed average frequencies for GSTM1 (null) and GSTT1 (null) were 41, 22 and 12.7%, respectively in normal subjects whereas frequencies of CYP1A1/GSTP1 with (ile/ile) or (ile/val) or (val/val) were found to be 76.2/52, 21.4/42.1 and 2.4/5.9% respectively. It was further observed that the frequencies of above genes were found to be similar in solvent exposed groups. The distribution frequencies of GST genes, when compared with other reports from various regions of India show variations. In vitro TCE exposure (2, 4 and or 6 mM) did not show any significant genotoxic effect. TCE may be toxic due to its metabolite.

The clinical significance of the expression level of PMEPA1 in prostate cancer / 复旦学报（医学版）

Objective To study the clinical significance of the mRNA expression level of a novel gene which encodes a kind of transmembrane prostate protein induced by androgen-PMEPA1, as it may predict the progress of prostate cancer from hormone-dependent to hormone-independent. Methods We used Real-time PCR to detect the mRNA expression of PMEPA1 and GSTP1 in prostate cancer cell lines (LNCaP, PC-3), epithelia cells of benign prostatic hyperplasia and tissues from 33 patients with prostate cancers and 16 cases of prostatic hyperplasia. Results We found the mRNA expression of GSTP1 and PMEPA1 were both down-regulated in prostate cancer cell lines. The mRNA expression of GSTP1 was up-regulated in 6.1% of cases, down-regulated in 81.8%, and showed no difference in 12.1%. While PMEPA1 was highly expressed in 27.3% of cases, lowly expressed in 27.3%, and not differently expressed in 45.4%. Statistical analysis showed that the mRNA expression of GSTP1 was relevant to ages, but had no relationship with PSA, TNM stage, osseous metastasis or tumor differentiation, while the mRNA expression of PMEPA1 was relevant to osseous metastasis and tumor differentiation, but had no relationship with age, PSA or TNM stage. Conclusions PMEPA1 is possibly a useful biomarker, as it can identify patients with unfavourable prognosis, however, this hypothesis needs to be further studied with large samples.