Objective Cytochrome P450 2E1 （CYP2E1） is an important metabolizing enzyme involved in oxidative stress responses to benzene, a chemical associated with bone marrow toxicity and leukemia, We aimed to identify the CY...Objective Cytochrome P450 2E1 （CYP2E1） is an important metabolizing enzyme involved in oxidative stress responses to benzene, a chemical associated with bone marrow toxicity and leukemia, We aimed to identify the CYP2E1 genetic biomarkers of susceptibility to benzene toxicity in support of environmental and occupational exposure prevention, and to test whether a model using immortal human lymphocytes might be an efficient tool for detecting genetic biomarkers. Methods Immortalized human lymphocyte cell lines with independent genotypes on four CYP2E1 SNP sites were induced with 0.01% phenol, a metabolite of benzene. CYP2E1 gene function was evaluated by mRNA expression and enzyme activity. DNA damage was measured by Single-Cell Gel Electrophoresis （SCGE）. Results Among the four SNPs, cells with rs2070673TT and rs2030920CC showed higher levels of ~YP2E1 transcription and enzymatic activity than the other genotypes in the same SNP site. Cells with higher gene expression genotypes also showed higher comet rates compared with lower gene expression genotypes. Conclusion These results suggest that CYP2E1 rs2070673 and rs2030920 might be the genetic biomarkers of susceptibility to benzene toxicity and that the immortalized human lymphocytes model might be an efficient tool for the detection of genetic biomarkers of susceptibility to chemicals.展开更多
AIM:To investigate hepatitis virus, genetic and environmental factors, and their interactions in predisposing patients to liver diseases in Northeast India. METHODS:A total of 104 jaundice patients and 124 community c...AIM:To investigate hepatitis virus, genetic and environmental factors, and their interactions in predisposing patients to liver diseases in Northeast India. METHODS:A total of 104 jaundice patients and 124 community controls were included. Serological analysis was performed by routine enzyme-linked immunosorbent assay, and nucleic acid testing for hepatitis viruses was done by polymerase chain reaction (PCR), followed by PCR direct sequencing for viral genotyping. Cytochrome P450 2E1 (CYP2E1) polymorphism was studied by PCR-restriction fragment length polymorphism. Nitrite and volatile nitrosamines in indigenous foods consumed routinely by the Northeast Indian ethnic population were estimated by Griess’s reagent and GC-MS, respectively.RESULTS: Hepatitis A virus (HAV) infection was predominantly prevalent (36.5%) in our cohort, followed by hepatitis B virus (HBV), hepatitis E virus (HEV) andhepatitis C virus. HBV genotype D and HEV genotype 1 were the most dominant. CYP2E1 c1/c2 genotype frequency was comparatively higher in alcoholic (P<0.0001,OR =30.5) and cryptogenic (P=0.014, OR=8.714) patients, and was associated with significantly higher hepatitis risk (P=0.0.007,OR=6.489). Mutant C allele of Cyp2E1 DraⅠ frequency was comparatively higher in HAV (P=0.006), alcoholic (P =0.003) and cryptogenic (P=0.014) cases, and was associated with overall hepatitis risk (P=0.026, OR=5.083). Indigenous foods, Gundruk, Kharoli, betel leaf and nuts were found to have the highest nitrite content. CONCLUSION: Apart from viral factors, CYP2E1 polymorphism might be associated with increased risk of liver diseases in Northeast India. Indigenous foods that contain nitrite and nitrosamine might be an associated risk factor.展开更多
AIM:To clarify the association between CYP2E1 PstⅠ/RsaⅠ polymorphism and susceptibility to colorectal cancer.METHODS:A meta-analysis based on 10 eligible casecontrol studies involving 4979 cases and 6012 controls wa...AIM:To clarify the association between CYP2E1 PstⅠ/RsaⅠ polymorphism and susceptibility to colorectal cancer.METHODS:A meta-analysis based on 10 eligible casecontrol studies involving 4979 cases and 6012 controls was carried out to summarize the data on the association between CYP2E1 RsaⅠ/PstⅠ polymorphism and colorectal cancer risk.RESULTS:In comparison of the homozygote c2c2 and c2 carriers(c1c2 + c2c2) and the homozygous wild-type genotype(c1c1),no association was found between CYP2E1 RsaⅠ/PstⅠ polymorphism and colorectal cancer risk [odds ratio(OR)=1.24(95% CI:0.93-1.66) for c2c2;OR = 1.02(95% CI:0.88-1.19) for c2 carriers].In stratif ied analysis,Caucasians with c2c2 homozygote appeared to have an increased risk of colorectal cancer(OR=2.67,95% CI:1.03-6.89,P=0.043),no signif icant associations were found in other groups.CONCLUSION:c2c2 homozygote of CYP2E1 PstⅠ/RsaⅠ polymorphism may be associated with the increased risk of colorectal cancer in Caucasians,which needs further investigations.展开更多
Cytochrome P450 CYP2E1 is mainly present in hepatocytes in the livers of mammals,where it plays an important role in the metabolism of xenobiotic organic substances. Previous studies showed that transgenic petunia(Pet...Cytochrome P450 CYP2E1 is mainly present in hepatocytes in the livers of mammals,where it plays an important role in the metabolism of xenobiotic organic substances. Previous studies showed that transgenic petunia(Petunia hybrid) plants harboring a mammalian cyp2e1 gene(designated cyp2e1-transgenic petunia) exhibited increased resistance to formaldehyde stress. In this study,we used cyp2e1-transgenic petunia plants to analyze physiological indexes related to formaldehyde stress responses. The results indicated that under formaldehyde stress,the malondialdehyde content in cyp2e1-transgenic petunia plants was lower than in β-glucuronidase gene(gus)-transgenic and wild-type petunia plants. The activities of both superoxide dismutase and peroxidase in the cyp2e1-transgenic plants were higher than in gus-transgenic and wild-type plants. The alcohol dehydrogenase activity was slightly increased and more glutathione was consumed. Additionally,under formaldehyde stress,the levels of plant hormones including indole-3-acetic acid,zeatin and abscisic acid in cyp2e1-transgenic petunia plants displayed decreasing trends,whereas the level of gibberellic acid displayed an increasing trend. In contrast,the indole-3-acetic acid,zeatin and abscisic acid levels in gus-transgenic and wild-type petunia plants displayed increasing trends,whereas the gibberellic acid level displayed a decreasing trend. At 72 h after incubation of 0.5 g of cyp2e1-transgenic petunia plants in 40 mL of treatment solution containing formaldehyde at 50 mg·L^(-1),the formaldehyde content remaining in the treatment solution was close to zero while approximately half of original formaldehyde remained in the treatment solutions containing gus-transgenic and wild-type petunia plants.展开更多
Background Cytochrome P450 2E1 （CYP2E1） has an important role in the metabolic activation of precarcinogens such as N-nitrosoamines and other low relative molecular mass, organic compounds. This study examined wheth...Background Cytochrome P450 2E1 （CYP2E1） has an important role in the metabolic activation of precarcinogens such as N-nitrosoamines and other low relative molecular mass, organic compounds. This study examined whether CYP2E1 Rsal and Dral polymorphism are associated with susceptibility to esophageal squamous cell carcinoma and the correlation between the genotypes and expression levels of CYP2E1 mRNA.Methods Seventy-seven patients with newly diagnosed, untreated esophageal squamous cell carcinoma and 79 healthy controls matched in age, gender and residence were recruited for the control study. An Rsal polymorphism in the 5＇-flanking region and a Dral polymorphism in the sixth intron of the CYP2E1 gene, which could possibly affect its transcription, were determined in this study by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） and mRNA level of CYP2E1 was measured by quantitative real-time reverse transcription PCR.Results No significant association of Rsal or Dral polymorphism of CYP2E1 with susceptibility of esophageal squamous cell carcinoma were demonstrated （OR=1.67, 95%CI： 0.89-3.15, P=0.11; OR=1.11, 95%CI： 0.59-2.09, P=0.74, respectively）. With SHEsis software, no linkage disequilibrium was detected between Rsal and Dral polymorphism （D＇=0.528, r^2=0.27）. When combined Rsal polymorphism with Dral polymorphism, the association between that carrying c2 allele and DD genotype and the risk for esophageal squamous cell carcinoma were found （OR=5.77, 95%CI： 1.65-20.22）. Compared with the normal controls, the mRNA levels with Rsal polymorphism, Dral polymorphism, or any combined genotypes in cases showed no statistical difference.Conclusions This study suggests that carrying c2 allele and DD genotype conferreded an elevated risk for esophageal squamous cell carcinoma. There was no significant statistical relationship between the genotypes c1/c2, D/C, or the combined allele and mRNA expression.展开更多
基金supported by the National Natural Science Foundation of China (Grant No: 30671731, 30901168)the Doctoral Program of Higher Education of China (Grant No: 20070286069)
文摘Objective Cytochrome P450 2E1 （CYP2E1） is an important metabolizing enzyme involved in oxidative stress responses to benzene, a chemical associated with bone marrow toxicity and leukemia, We aimed to identify the CYP2E1 genetic biomarkers of susceptibility to benzene toxicity in support of environmental and occupational exposure prevention, and to test whether a model using immortal human lymphocytes might be an efficient tool for detecting genetic biomarkers. Methods Immortalized human lymphocyte cell lines with independent genotypes on four CYP2E1 SNP sites were induced with 0.01% phenol, a metabolite of benzene. CYP2E1 gene function was evaluated by mRNA expression and enzyme activity. DNA damage was measured by Single-Cell Gel Electrophoresis （SCGE）. Results Among the four SNPs, cells with rs2070673TT and rs2030920CC showed higher levels of ~YP2E1 transcription and enzymatic activity than the other genotypes in the same SNP site. Cells with higher gene expression genotypes also showed higher comet rates compared with lower gene expression genotypes. Conclusion These results suggest that CYP2E1 rs2070673 and rs2030920 might be the genetic biomarkers of susceptibility to benzene toxicity and that the immortalized human lymphocytes model might be an efficient tool for the detection of genetic biomarkers of susceptibility to chemicals.
基金Supported by Gauhati University,Guwahati,Assam,India
文摘AIM:To investigate hepatitis virus, genetic and environmental factors, and their interactions in predisposing patients to liver diseases in Northeast India. METHODS:A total of 104 jaundice patients and 124 community controls were included. Serological analysis was performed by routine enzyme-linked immunosorbent assay, and nucleic acid testing for hepatitis viruses was done by polymerase chain reaction (PCR), followed by PCR direct sequencing for viral genotyping. Cytochrome P450 2E1 (CYP2E1) polymorphism was studied by PCR-restriction fragment length polymorphism. Nitrite and volatile nitrosamines in indigenous foods consumed routinely by the Northeast Indian ethnic population were estimated by Griess’s reagent and GC-MS, respectively.RESULTS: Hepatitis A virus (HAV) infection was predominantly prevalent (36.5%) in our cohort, followed by hepatitis B virus (HBV), hepatitis E virus (HEV) andhepatitis C virus. HBV genotype D and HEV genotype 1 were the most dominant. CYP2E1 c1/c2 genotype frequency was comparatively higher in alcoholic (P<0.0001,OR =30.5) and cryptogenic (P=0.014, OR=8.714) patients, and was associated with significantly higher hepatitis risk (P=0.0.007,OR=6.489). Mutant C allele of Cyp2E1 DraⅠ frequency was comparatively higher in HAV (P=0.006), alcoholic (P =0.003) and cryptogenic (P=0.014) cases, and was associated with overall hepatitis risk (P=0.026, OR=5.083). Indigenous foods, Gundruk, Kharoli, betel leaf and nuts were found to have the highest nitrite content. CONCLUSION: Apart from viral factors, CYP2E1 polymorphism might be associated with increased risk of liver diseases in Northeast India. Indigenous foods that contain nitrite and nitrosamine might be an associated risk factor.
文摘AIM:To clarify the association between CYP2E1 PstⅠ/RsaⅠ polymorphism and susceptibility to colorectal cancer.METHODS:A meta-analysis based on 10 eligible casecontrol studies involving 4979 cases and 6012 controls was carried out to summarize the data on the association between CYP2E1 RsaⅠ/PstⅠ polymorphism and colorectal cancer risk.RESULTS:In comparison of the homozygote c2c2 and c2 carriers(c1c2 + c2c2) and the homozygous wild-type genotype(c1c1),no association was found between CYP2E1 RsaⅠ/PstⅠ polymorphism and colorectal cancer risk [odds ratio(OR)=1.24(95% CI:0.93-1.66) for c2c2;OR = 1.02(95% CI:0.88-1.19) for c2 carriers].In stratif ied analysis,Caucasians with c2c2 homozygote appeared to have an increased risk of colorectal cancer(OR=2.67,95% CI:1.03-6.89,P=0.043),no signif icant associations were found in other groups.CONCLUSION:c2c2 homozygote of CYP2E1 PstⅠ/RsaⅠ polymorphism may be associated with the increased risk of colorectal cancer in Caucasians,which needs further investigations.
基金supported by the Hangzhou Science and Technology Development Plan(Grant No.20140432B05)the New-shoot Talents Program of Zhejiang Province(Grant No.2013R421008)
文摘Cytochrome P450 CYP2E1 is mainly present in hepatocytes in the livers of mammals,where it plays an important role in the metabolism of xenobiotic organic substances. Previous studies showed that transgenic petunia(Petunia hybrid) plants harboring a mammalian cyp2e1 gene(designated cyp2e1-transgenic petunia) exhibited increased resistance to formaldehyde stress. In this study,we used cyp2e1-transgenic petunia plants to analyze physiological indexes related to formaldehyde stress responses. The results indicated that under formaldehyde stress,the malondialdehyde content in cyp2e1-transgenic petunia plants was lower than in β-glucuronidase gene(gus)-transgenic and wild-type petunia plants. The activities of both superoxide dismutase and peroxidase in the cyp2e1-transgenic plants were higher than in gus-transgenic and wild-type plants. The alcohol dehydrogenase activity was slightly increased and more glutathione was consumed. Additionally,under formaldehyde stress,the levels of plant hormones including indole-3-acetic acid,zeatin and abscisic acid in cyp2e1-transgenic petunia plants displayed decreasing trends,whereas the level of gibberellic acid displayed an increasing trend. In contrast,the indole-3-acetic acid,zeatin and abscisic acid levels in gus-transgenic and wild-type petunia plants displayed increasing trends,whereas the gibberellic acid level displayed a decreasing trend. At 72 h after incubation of 0.5 g of cyp2e1-transgenic petunia plants in 40 mL of treatment solution containing formaldehyde at 50 mg·L^(-1),the formaldehyde content remaining in the treatment solution was close to zero while approximately half of original formaldehyde remained in the treatment solutions containing gus-transgenic and wild-type petunia plants.
基金the National Nature Science Foundation of China(No.30671732 and No.30571540)the Preventive Medicine Foundation of Jiangsu Province(No.Y2006007)the National Science Development Foundation of Southeast University(No.XJ0525212)
文摘Background Cytochrome P450 2E1 （CYP2E1） has an important role in the metabolic activation of precarcinogens such as N-nitrosoamines and other low relative molecular mass, organic compounds. This study examined whether CYP2E1 Rsal and Dral polymorphism are associated with susceptibility to esophageal squamous cell carcinoma and the correlation between the genotypes and expression levels of CYP2E1 mRNA.Methods Seventy-seven patients with newly diagnosed, untreated esophageal squamous cell carcinoma and 79 healthy controls matched in age, gender and residence were recruited for the control study. An Rsal polymorphism in the 5＇-flanking region and a Dral polymorphism in the sixth intron of the CYP2E1 gene, which could possibly affect its transcription, were determined in this study by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） and mRNA level of CYP2E1 was measured by quantitative real-time reverse transcription PCR.Results No significant association of Rsal or Dral polymorphism of CYP2E1 with susceptibility of esophageal squamous cell carcinoma were demonstrated （OR=1.67, 95%CI： 0.89-3.15, P=0.11; OR=1.11, 95%CI： 0.59-2.09, P=0.74, respectively）. With SHEsis software, no linkage disequilibrium was detected between Rsal and Dral polymorphism （D＇=0.528, r^2=0.27）. When combined Rsal polymorphism with Dral polymorphism, the association between that carrying c2 allele and DD genotype and the risk for esophageal squamous cell carcinoma were found （OR=5.77, 95%CI： 1.65-20.22）. Compared with the normal controls, the mRNA levels with Rsal polymorphism, Dral polymorphism, or any combined genotypes in cases showed no statistical difference.Conclusions This study suggests that carrying c2 allele and DD genotype conferreded an elevated risk for esophageal squamous cell carcinoma. There was no significant statistical relationship between the genotypes c1/c2, D/C, or the combined allele and mRNA expression.
