AIM: To analyze the relationship between genetic polymorphisms of metabolizing enzymes CYP2E1, GSTM1 andKazakh's esophageal squamous cell cancer in China.METHODS: The genotypes of cytochromes P450 (CYP) 2E1 and gl...AIM: To analyze the relationship between genetic polymorphisms of metabolizing enzymes CYP2E1, GSTM1 andKazakh's esophageal squamous cell cancer in China.METHODS: The genotypes of cytochromes P450 (CYP) 2E1 and glutathione S-transferase (GST) M1 were investigated by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) following PCR in 104 Kazakh's patients with esophageal cancer (EC) and 104 non-cancer controls.RESULTS: The frequency of CYP2E1 c1/c1 genotype was significantly higher in patients with cancer (77.9%) thanin control subjects (24.0%) (P＜0.05; OR, 11.13; 95%CI,5.84-21.22). The difference of GSTM1 null was significantly more frequent in the cancer (34.6%) vsthe control group (3.8%) (P＜0.05; OR, 13.24; 95%CI, 4.50-38.89). On the other hand, the combination of GSTM1 presence and CYP2E1 c1/c1 genotypes increased the risk for cancer (P＜0.05;OR, 13.42; 95%CI, 6.29-28.3).CONCLUSION: The CYP2E1 c1/c1, GSTM1 deletion genotypes are genetically susceptible biomarkers for ESCC in Kazakh population. Individuals with allele c1 of RsaI polymorphic locus for CYP2E1 may increase the risk of ESCC. Moreover, CYP2E1 wild type (c1/c1) increased thesusceptibility to ESCC risk in Kazakh individuals with GSTM1 presence genotype.展开更多
MIM:To test the hypothesis that,in the Southeastern Brazilian population,the GSTT1,GSTM1 and CYP2E1 polymorphisms and putative risk factors are associated with an increased risk for gastric cancer.METHODS:We conducted...MIM:To test the hypothesis that,in the Southeastern Brazilian population,the GSTT1,GSTM1 and CYP2E1 polymorphisms and putative risk factors are associated with an increased risk for gastric cancer.METHODS:We conducted a study on 100 cases of gastric cancer(GC),100 cases of chronic gastritis(CG),and 150 controls(C).Deletion of the GSTT1 and GSTM1 genes was assessed by multiplex PCR.CYP2E1/PsА genotyping was performed using a PCR-RFLP assay.RESULTS:No relationship between GSTT1/GSTM1 deletion and the c1/c2 genotype of CYP2E1 was observed among the three groups.However,a significant difference between CG and C was observde,due to a greater number of GSTT1/GSTM1 positive genotypes in the CG group.The GSTT1 null genotype occurred more frequently in Negroid subjicts,and the GSTM1 null genotype was observed mainly in individuals with chronic gastritis infected with H pylori.CONCLUSION:Our findings indecate that there is no obvious relationship between the GSTT1,GSTM1 and CYP2E1 polymorphisms and gastric cancer.展开更多
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: Genetic polymorphism in enzymes of carcinogen metabolism has been found to have the influence on the susceptibility to cancer. Cytochrome P450 2E1 ( CYP2 E1) is considered to play an important role in the metabol...AIM: Genetic polymorphism in enzymes of carcinogen metabolism has been found to have the influence on the susceptibility to cancer. Cytochrome P450 2E1 ( CYP2 E1) is considered to play an important role in the metabolic activation of procarcinogens such as N-nitroscoamines and Iow molecular weight organic compounds. The purpose of this study is to determine whether CYP450 2Elpolymorphisms are associated with risk s of gastric cancer.METHODS: We conducted a population based case-control study in Changle county, Fujian Province, a high-risk region of gastric cancer in China. Ninety-one incident gastric cancer patients and ninety-four healthy controls were included in our study. Datas including dsmographic characteristcs, diet intake, and alcohol and tobacco consumption of indivduals in our study were completed by a standardized questionnaire. PCR-RFLP revealed three genotypes: heterozygote (C1/C2) and two homozygotes (C1/C1 and C2/C2) in CYP2E1.RESULTS: The frequency of variant genotypes (C1/C2 and C2/C2) in gastric cancer cases and controls was 36.3% and 24.5%, respectively. The rare homozygous C2/C2 genotype was found in 6 indivduals in gastric cancer group(6.6%),whereas there was only one in the control group (1.1%).However, there was no statistically significan difference between the two groups (two-tailed Fisher′s exact test, P =0.066). Indivduals in gastric cancer group were more likely to carry genotype C1/C2 (odds ratio, OR = 1.50) and C2/C2(OR = 7.34) than indivduals in control group (X2 = 4.597, for trend P=0.032). The frequencies of genofypes with the C2allele ( C1/C2 and C2/C2 genotypes) were compared with those of genotypes without C2 allele ( C1/C1 genotype )among indivduals in gastric cancer group and control group according to the pattern of gastric cancer risk factors. The results show that indivduals who exposed to these gastric cancer risk factors and carry the C2 allele seemed to have a higher risk of developing gastric cancer.CONCLUSION: Polymorphism of CYP2E1 gene may have some effct in the development of gastric cancer in Changle county, Fujian Province.展开更多
基金Supported by the Xinjiang Key Lab Fund, XJDX0202-2003-05
文摘AIM: To analyze the relationship between genetic polymorphisms of metabolizing enzymes CYP2E1, GSTM1 andKazakh's esophageal squamous cell cancer in China.METHODS: The genotypes of cytochromes P450 (CYP) 2E1 and glutathione S-transferase (GST) M1 were investigated by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) following PCR in 104 Kazakh's patients with esophageal cancer (EC) and 104 non-cancer controls.RESULTS: The frequency of CYP2E1 c1/c1 genotype was significantly higher in patients with cancer (77.9%) thanin control subjects (24.0%) (P＜0.05; OR, 11.13; 95%CI,5.84-21.22). The difference of GSTM1 null was significantly more frequent in the cancer (34.6%) vsthe control group (3.8%) (P＜0.05; OR, 13.24; 95%CI, 4.50-38.89). On the other hand, the combination of GSTM1 presence and CYP2E1 c1/c1 genotypes increased the risk for cancer (P＜0.05;OR, 13.42; 95%CI, 6.29-28.3).CONCLUSION: The CYP2E1 c1/c1, GSTM1 deletion genotypes are genetically susceptible biomarkers for ESCC in Kazakh population. Individuals with allele c1 of RsaI polymorphic locus for CYP2E1 may increase the risk of ESCC. Moreover, CYP2E1 wild type (c1/c1) increased thesusceptibility to ESCC risk in Kazakh individuals with GSTM1 presence genotype.
文摘MIM:To test the hypothesis that,in the Southeastern Brazilian population,the GSTT1,GSTM1 and CYP2E1 polymorphisms and putative risk factors are associated with an increased risk for gastric cancer.METHODS:We conducted a study on 100 cases of gastric cancer(GC),100 cases of chronic gastritis(CG),and 150 controls(C).Deletion of the GSTT1 and GSTM1 genes was assessed by multiplex PCR.CYP2E1/PsА genotyping was performed using a PCR-RFLP assay.RESULTS:No relationship between GSTT1/GSTM1 deletion and the c1/c2 genotype of CYP2E1 was observed among the three groups.However,a significant difference between CG and C was observde,due to a greater number of GSTT1/GSTM1 positive genotypes in the CG group.The GSTT1 null genotype occurred more frequently in Negroid subjicts,and the GSTM1 null genotype was observed mainly in individuals with chronic gastritis infected with H pylori.CONCLUSION:Our findings indecate that there is no obvious relationship between the GSTT1,GSTM1 and CYP2E1 polymorphisms and gastric cancer.
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 Natural Science Foundation of Fujian Province,China,No.C001009
文摘AIM: Genetic polymorphism in enzymes of carcinogen metabolism has been found to have the influence on the susceptibility to cancer. Cytochrome P450 2E1 ( CYP2 E1) is considered to play an important role in the metabolic activation of procarcinogens such as N-nitroscoamines and Iow molecular weight organic compounds. The purpose of this study is to determine whether CYP450 2Elpolymorphisms are associated with risk s of gastric cancer.METHODS: We conducted a population based case-control study in Changle county, Fujian Province, a high-risk region of gastric cancer in China. Ninety-one incident gastric cancer patients and ninety-four healthy controls were included in our study. Datas including dsmographic characteristcs, diet intake, and alcohol and tobacco consumption of indivduals in our study were completed by a standardized questionnaire. PCR-RFLP revealed three genotypes: heterozygote (C1/C2) and two homozygotes (C1/C1 and C2/C2) in CYP2E1.RESULTS: The frequency of variant genotypes (C1/C2 and C2/C2) in gastric cancer cases and controls was 36.3% and 24.5%, respectively. The rare homozygous C2/C2 genotype was found in 6 indivduals in gastric cancer group(6.6%),whereas there was only one in the control group (1.1%).However, there was no statistically significan difference between the two groups (two-tailed Fisher′s exact test, P =0.066). Indivduals in gastric cancer group were more likely to carry genotype C1/C2 (odds ratio, OR = 1.50) and C2/C2(OR = 7.34) than indivduals in control group (X2 = 4.597, for trend P=0.032). The frequencies of genofypes with the C2allele ( C1/C2 and C2/C2 genotypes) were compared with those of genotypes without C2 allele ( C1/C1 genotype )among indivduals in gastric cancer group and control group according to the pattern of gastric cancer risk factors. The results show that indivduals who exposed to these gastric cancer risk factors and carry the C2 allele seemed to have a higher risk of developing gastric cancer.CONCLUSION: Polymorphism of CYP2E1 gene may have some effct in the development of gastric cancer in Changle county, Fujian Province.
