Yeast One-hybrid System Used to Identify the Binding Proteins for Rat Glutathione S-transferase P Enhancer I

Objective To detect the trans-factors specifically binding to the strong enhancerelement (GPEI) in the upstream of rat glutathione S-transferase P (GST-P) gene. MethodsYeast one-hybrid system was used to screen rat lung MATCHMAKER cDNA library toidentify potential trans-factors that can interact with core sequence of GPEI(cGPEI).Electrophoresis mobility shift assay (EMSA) was used to analyze the binding of trans-factors to cGPEI. Results cDNA fragments coding for the C-terminal part of thetranscription factor c-Jun and rat adenine nucleotide translocator (ANT) were isolated. Thebinding of c-Jun and ANT to GPEI core sequence were confirmed. Conclusions Rat c-juntranscriptional factor and ANT may interact with cGPEI. They could play an important rolein the induced expression of GST-P gene.

Polymorphisms of the oxidant enzymes glutathione S-transferase and glutathione reductase and their association with resistance of Plasmodium falciparum isolates to antimalarial drugs

Objective:To investigate the association between amplification of the two regulatory genes controlling glutathione(GSH) levels,glutathione reductase(PfGR) and glutathione S-transferase (PfGST) genes and sensitivity of Plasmodium falciparum(P.falciparum) isolates collected from different malaria endemic areas of Thailand to standard antimalarial drugs.Methods:A total of 70 P.falciparum isolates were collected from endemic areas of multi-drug resistance (Tak,Chantaburi and Ranong Provinces) during the year 2008-2009.The in vitro assessment of antimalarial activity of P.falciparum clones(K1- and Dd2 chloroquine resistant and 3D7- chloroquine sensitive) and isolates to chloroquine,quinine,mefloquine and arteusnate was performed based on SYBR Green modified assay.Results:68(97.14%),11(15.71%) and 28(40%) isolates respectively were classified as chloroquine-,quinine- and mefloquine-resistant isolates. With this limited number of P.falciparum isolates included in the analysis,no significant association between amplification of PfGST gene and sensitivity of the parasite to chloroquine, quinine,mefloquine and quinine was found.Based on PCR analysis,Dd2,Kl and 3D7 clones all contained only one copy of the PfGST gene.All isolates(70) also carried only one copy number of PfGST gene.There appears to be an association between amplification of PfGR gene and chloroquine resistance.The 3D7 and Dd2 clones were found to carry only one PfGR gene copy, whereas the K1 clone carried two gene copies.Conclusions:Chloroquine resistance is likely to be a consequence of multi-factors and enzymes in the GSH system may be partly involved. Larger number of parasite isolates are required to increase power of the hypothesis testing in order to confirm the involvement of both genes as well as other genes implicated in glutathione metabolism in conferring chloroquine resistance.

Anticancer Drug Resistance of HeLa Cells Transfected With Rat Glutathione S-transferase pi Gene

To establish a cytologic expressing system of rat glutathione S-transferase pi (GST-pi) cDNA for detecting the resistance of HeLa cells to anticancer drugs. Methods The assessment was made with various anticancer drugs (adriamycin, mitomycin, cisplatinum and vincristine) that showed different cytotoxicities in transfectant HeLa cells with pSV-GT containing rat GST-pi cDNA (HeLa/pSV-GT) or control pSV-neo (HeLa/pSV-neo). Expression levels of GST-pi mRNA in HeLa/pSV-GT and HeLa/pSV-neo were measured by in situ hybridization using Digoxin-labelled cDNA probe. Results HeLa/pSV-GT expressed significantly high degree of GST-pi mRNA, whereas both HeLa/pSV-neo and HeLa cells had very low expression. Cytotoxicities of HeLa/pSV-GT and HeLa/pSV-neo with 4 anticancer drugs were measured by MTT assay. Drug concentrations for yielding 50% inhibition (IC50) in HeLa/pSV-GT by adriamycin, mitomycin and cisplatinum were 70.13 靏/mL, 10.95 靏/mL and 16.52 靏/mL, respectively. In contrast, IC50 in HeLa/pSV-neo was 10.34 靏/mL, 7.48 靏/mL and 13.70 靏/mL, respectively. The cytotoxicities of vincristine on both HeLa/pSV-GT and HeLa/pSV-neo were not significantly different. Conclusions Our findings suggest that HeLa/pSV-GT containing rat GST-pi cDNA is resistant to some anticancer drugs due to overexpression of GST-pi. Also, HeLa/pSV-GT cell line could serve as a useful cytogenetic model for further research.

A systemic review of glutathione S-transferase P1 Ile105Val polymorphism and colorectal cancer risk

Objectives： To investigate the correlation between glutathione S-transferase P1 （GSTP1） Ilel05Val polymorphism and colorectal cancer （CRC） risk. Methods： Studies were identified to investigate the association between GSTP1 Ilel05Val polymorphism and CRC risk. Systematic computerized searches of the PubMed, Chinese National Knowledge Infrastructure, WANFANG and SinoMed were performed. Summary odds ratios （OR） and 95% confidence intervals （95 % CI） were used to measure GSTP 1 Ile 105Val polymorphisms and CRC risk. Results： A total of 23 retrospective studies were included in the meta-analysis. During all studies including 6,981 cases and 8,977 controls, sample sizes ranged from 146 to 2,144. Overall, the pooled results revealed that lie 105Val polymorphism was not associated with CRC risk and confused results were found in subgroup analyses. Further meta-analyses were conducted after excluding low-quality studies. GSTP1 Ilel05Val is associated with increased risk of CRC limited in studies with matched control. There was no significant heterogeneity in all genetic comparisons, but heterogeneity existed in subgroup analyses of heterozygous and dominant comparisons. The meta-regression analyses indicated that matched controls were the significant factor influencing between-study heterogeneity in all possible influential factors including published year, ethnicity, source of control, sample size, Hardy-Weinberg equilibrium （HWE） in control and matched controls. Sensitivity analysis revealed the pooled ORs were not changed before and after removal of each single study in all genetic comparisons, indicating the robustness of the results. Conclusions： GSTP1 Ilel05Val might be associated with increased risk of CRC. However, more high- quality case-control studies should be performed to confirm the authenticity of our conclusion.

Effect of trans-acting factor on rat glutathione S-transferase P1 gene transcription regulation in tumor cells

Objective To investigate the effect of trans-acting factor(s) on rat glutathione S-transferase P1 gene (rGSTP1) transcription regulation in tumor cells.Methods The binding of trans-acting factor(s) to two enhancers of the rGSTP1 gene, glutathione S-transferase P enhancer Ⅰ (GPEI) and glutathione S-transferase P enhancer Ⅱ-1 (GPEⅡ-1), was identified by an electrophoretic mobility shift assay (EMSA). The molecular weight of trans-acting factor was measured in a UV cross-linking experiment. Results Trans-acting factor interacting with the core sequence of GPEI (cGPEI) were found in human cervical adenocarcinoma cell line (HeLa) and rat hepatoma cell line (CBRH7919). These proteins were not expressed in normal rat liver. Although specific binding proteins that bound to GPEⅡ-1 were detected in all three cell types, a 64 kDa binding protein that exists in HeLa and CBRH7919 cells was absent in normal rat liver. Conclusion cGPEI, GPEII specific binding proteins expressed in HeLa and CBRH7919 cells may play an important role in the high transcriptional level of the rGSTP1 gene in tumor cells.

Relationship between polymorphisms of genes encoding microsomal epoxide hydrolase and glutathione S-transferase P1 and chronic obstructive pulmonary disease

Background Cigarette smoking is the major risk factor for chronic obstructive pulmonary disease (COPD) However, only 10%-20% of chronic heavy cigarette smokers develop symptomatic disease COPD is most likely the result of complex interactions between environmental and genetic factors Genetic susceptibility to COPD might depend on the variations in enzyme activities that detoxify cigarette smoke products, such as microsomal epoxide hydrolase (mEH) and glutathione S-transferase (GST) In this study, we investigated the relationship between polymorphisms in the genes encoding mEH and glutathione S-transferase P1 (GSTP1) and COPD in a Chinese population Methods Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed to find mEH polymorphism in exon 3 (Tyr113→His), exon 4 (His139→Arg) and GSTP1 polymorphism in exon 5 (Ile105→Val) in 100 COPD patients and 100 age- and sex-matched healthy controls Results The proportion of mEH exon 3 heterozygotes was significantly higher in patients with COPD than that in the control subjects (42% vs 32%) The odds ratio ( OR ) adjusted by age, sex, body mass index (BMI) and cigarette years was 2 96 (95% CI 1 24-7 09) There was no marked difference in very slow activity genotype versus other genotypes between COPD patients and the controls When COPD patients were non-smokers, the OR of very slow activity genotype versus other genotypes was more than 1 00; and when COPD patients were smokers (current smokers and ex-smokers), the OR was less than 1 00 There was no significant difference in GSTP1 polymorphism adjusted by age, sex, BMI and smoking between COPD patients and the controls Conclusions mEH exon 3 heterozygotes might be associated with susceptibility to COPD in China The interaction might exist between mEH genotype and smoke The gene polymorphism for GSTP1 might not be associated with susceptibility to COPD in the Chinese population

应用酵母单杂交体系筛选与大鼠谷胱甘肽S-转移酶P增强子GPEⅠ相互作用的转录激活因子

目的 探讨谷胱甘肽 S-转移酶 (GST- P)基因表达调控机制的多样性及其与化学致癌的关系 ,筛选与大鼠 GST- P增强子元件 GPE 相互作用的调控因子。方法 采用酵母单杂交体系筛选与 GPE 核心序列相互作用的转录激活因子 ,应用 DNA序列测定及计算机分析等手段对所测的 DNA序列进行分析。结果 共获得两个阳性克隆 p YGPE1和 p YGPE2。 DNA测序分析表明 :p YGPE1的插入片段与大鼠原癌基因 c- jun c DNA具有 99%的同源性 ,其编码的氨基酸序列与大鼠 c- Jun蛋白具有 10 0 %的同源性。 p YGPE2的插入片段与大鼠线粒体腺苷酸转位酶 c DNA具有 99%的同源性 ,其编码的氨基酸序列与大鼠腺苷酸转位酶具有 10 0 %的同源性。结论 大鼠 c- Jun蛋白和线粒体腺苷酸转位酶在酵母细胞内与大鼠 GST- P增强子 GPE 核心序列结合 ,可能是作用于 GPE 的反式作用因子。

Evaluation in vinyl chloride monomer-exposed workers and the relationship between liver lesions and gene polymorphisms of metabolic enzymes

AIM： To analyze occupational health hazards exposure to doses lower than the Chinese occupational health standard in a selected VC polymerization plant in China, and also to elucidate the relationship between genetic polymorphisms and genetic susceptibility on liver lesions of workers exposed to vinyl chloride monomer （VCM）. METHODS： In order to explore the mechanism of VCM- related health effects, we used a case-control design to investigate the association between the genetic polymorphisms of metabolic enzymes and liver lesions in workers occupationally exposed to VCM. Genotypes of CYP2E1, GSTT1, GSTM1, ALDH2 and ADH2 were identified using PCR and PCR-RFLP. RESULTS： Even when the concentration of VCM was lower than the current Chinese occupational health standard, neurasthenia, pharyngeal irritation, liver ultrasonography abnormalities and hemoglobin disorders were significantly higher in exposure subjects compared to non-exposure subjects, and the relative risks （RRand 95% C1） were 1.74 （1.06-2.85）, 1.97 （1.56-2.48）, 10.69 （4.38-26.12）, and 2.07 （1.20-3.57）. CYP2E1 c1c2/c2c2 genotype was significantly associated with liver damages （OR 3.29, 95% CI 1.51-7.20, P〈0.01）. CONCLUSION： The incidences of neurasthenia and liver ultrasonography abnormalities significantly increase when the cumulative exposure dose increases. The genotypes of metabolic enzymes （CYP2E1 c1c2/c2c2, null GSTT1 and ADH2 1-1） play important roles in VCM metabolism. Polymorphisms of CYP 2E1, GSTT1 and ADH2 may be a major reason of genetic susceptibility in VCM-induced hepatic damage.

Genetic polymorphism of T6235C mutation in 3' non-coding region of CYP1A1 and GSTM1 genes and lung cancer susceptibility in the Mongolian population

Objective To estimate the relative risk for lung cancer associated with genetic polymorphism of T6235C mutation in 3’ non-coding region(MspⅠ)of cytochrome P450 1A1(CYP1A1)and glutathione S-transferase M1(GSTM1)in the Mongolian population in Inner Mongolian Region of China.Methods Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP)and multiplex PCR methods were used to analyze blood samples obtained from 263 case subjects and 263 control subjects to determine their genotypes for CYP1A1 and GSTM1.Control subjects were matched with case subjects by ethnic background,age and gender.Results The frequencies of the variant CYP1A1 genotypes(CYP1A1C)and GSTM1-null in lung cancer groups were higher than those in control groups(38.4% vs.28.5% and 57.8% vs.48.0%).The individuals who carried with CYP1A1C genotype had a significantly higher risk of lung cancer(OR=1.56,95% CI=1.08 to 2.25,P=0.016)than those who carried with non-variation CYP1A1 genotype.The ones who carried with GSTM1-null genotype also had a significantly higher risk of lung cancer(OR=1.49,95% CI=1.06 to 2.10,P=0.023)than those who carried with GSTM1-present genotype.When combination of polymorphisms of CYP1A1 and GSTM1 genotypes was analyzed,the risk of lung cancer for combination of CYP1A1C and GSTM1-null genotypes was increased significantly(OR=2.084,95% CI=1.27 to 3.42,P=0.003).Susceptibility to lung cancer was related to smoking(OR=2.10,95% CI=1.48 to 2.98,P=0.000).Considering smoking status,the risk of lung cancer for combination of smoking and CYP1A1C genotype was remarkably increased(OR=2.76,95% CI=1.74 to 4.37,P=0.000).It was the same case with combination of smoking and GSTM1-null genotype(OR=4.38,95% CI=2.35 to 8.15,P=0.000).Conclusion The polymorphisms of CYP1A1C genotype and GSTM1-null are the risk factors of lung cancer in the Mongolian population in Inner Mongolia Region of China.Smoking is also related to susceptibility to lung cancer.There may be a synergetic interaction between CYP1A1C and GSTM1-null in the elevated susceptibility of lung cancer.Smoking may have a synergetic interaction with CYP1A1C and GSTM1-null in the elevated susceptibility of lung cancer.

Insecticide toxicity associated with detoxification enzymes and genes related to transcription of cuticular melanization among color morphs of Asian citrus psyllid

The Asian citrus psyllid (Diaphorina citri Kuwayama) is known to exhibit abdominal color polymorphisms. In the current study, susceptibility to four insecticides was compared among orange/yellow, blue/green and gray/brown color morphs of field collected D. citri. The LD50 values and 95% fiducial limits were quantified for each insecticide and color morph combination and ranged between 0.10 ng/μL (0.06-0.10) and 6.16 ng//μL (3.30-12.50). Second, we measured the detoxification enzyme activity levels of orange/yellow, blue/green and gray/brown color morphs for cytochrome P450, glutathione "S-transferase, and general esterase. The mean P450 activity (equivalent units) was significantly lower in gray/brown (0.152 ± 0.006) and blue/green morphs (0.149 ± 0.005) than in the orange/yellow morphs (0.179 ± 0.008). GST activity (/imol/min/mg protein) was significantly lower in the orange/yellow morph (299.70 ± 1.24) than gray/brown (350.86 ± 1.19) and blue/green (412.25 ±1.37) morphs. The mean EST activity (/xmol/min/mg protein) was significantly higher in blue/green (416.72±5.12) and gray/brown morphs (362.19 ± 4.69) than in the orange/yellow morphs (282.56 ± 2.93). Additionally, we analyzed the relative expression of assortment genes involved in cuticular melanization and basal immunity. The transcripts of Dopa Decarboxylase and Tyrosine Hydroxylase were expressed higher in blue/green and gray/brown than orange/yellow morphs. The transcription results paralleled the susceptibility of D.citri to organophosphate, neonicotinoid and pyrethroid insecticides. GST and EST activity may also be correlated with low levels of insecticide susceptibility. Cuticular melanization could be a factor for the development of resistance to insecticides among different color morphs.

Effects and mechanisms of three kinds of chemical inducers on the expression of rat GST-P gene

The expression of rat Glutathione S-transferase P (GST-P) gene can be induced by many kinds of chemical inducers. We have studied the mechanisms of the expression of GST-P gene induced by 3 kinds of Chemical inducers using the induction of the gene expression by chemical inducers, transient transfection, reporter gene assays, electrophoretic mobility shift assays (EMSA) and Northern blot analysis. The results indicate that the effects and mechanisms of chemical inducers on the expression of GS7'-Pgene are different. The interaction of AP-1 or other corresponding transcription factors activated by phorbol ester (TPA) or glycidyl methatylate (GMA) and GPEl enhancer element induces the expression of GST-P gene, while some unknown factors activated by H2O2 interact with GPEII enhancer element.

Anti-Tumor Effect and Anti-Inflammatory Activity of Boschniakia rossica

Objective: To investigate the anti-tumor effect and anti-inflammatory activity ofBoschniakia rossica (BR).Methods: The expression of tumor marker, GST-P, p53 and p21ras proteins in promotion stage of rat chemical hepatocarcinogenesis were examined by immunohistochemical technique ABC method. Anti-tumor effect of BR was investigated by inhibitory test on Sarcoma180. Anti-inflammatory activity of BR was tested by xylene-induced mouse ear swelling method.Results: BR-H2O extract (the H2O extract fractionated from BR-Methanol extract with CH2Cl2 and H2O) 500 mg/kg has inhibitory effect on the formation of diethylnitrosamine (DEN)-induced glutathione S-transferase placental form (GST-P) positive foci in rat liver with the expression of mutant p53 and p21ras proteins lower than those of non-treated hepatic preneoplastic lesions. BR extract showed inhibitory effect on Sarcoma180 and anti-inflammatory effect in mice by xylene-induced mouse ear swelling tests.conclusion: BR-H2O extract exerted inhibitory effect on DEN-induced preneoplastic hepatic foci in promotion stage of rat chemical hepatocarcinogenesis and might suppress the growth of solid Sarcoma180 in mice. Both CH2Cl2 and H2O extract from BR exerted anti-inflammatory effect in mice.