[A 1:2 matched case-control study on the interaction of HPV16E6 and HLA-DR9 allele to esophageal cancer in Kazakh ethnicity, Xinjiang].

OBJECTIVE: To evaluate the role and the association between HPV16E6 infection and HLA-DR9 immune-associated gene to esophageal cancer (EC) in Kazakh of Xinjiang, China. METHODS: A 1:2 matched case-control study was conducted with 63 cases of EC and 126 controls involved. The controls were matched by sex, nationality, area of residence and age within 5-year difference. HPV16E6 and HLA-DR9 allele were identified by PCR-SSP. Interaction was performed to identify risk factors. RESULTS: HPV16E6 infection and HLA-DR9 allele positive status were the risk factors for EC, with OR values as 2.67 (95%CI: 1.38 - 5.17) and 3.83 (95%CI: 1.48 - 9.96) respectively. The rate of HPV16E6 infection in individuals with HLA-DR9 allele was different from the ones who were HLA-DR9 allele free (chi(2) = 7.57, P = 0.006), with OR value as 5.79 (95%CI: 1.53 - 21.87). In the controls, the rates of HPV16E6 infection were 22.2% and 16.2% among individuals with HLA-DR9 allele atatus as positive or negative, and without statistically significant difference. Interaction analysis showed there was an interaction of HPV16E6 with HLA-DR9 and were higher than the sum of the two factors presented individually. CONCLUSION: In our study, we found that the HLA-DR9 allele and HPV16E6 infection had a function of synergy in the process of malignant transformation of esophageal epithelial cells, and jointly promoting the occurrence and development of EC.

Interaction of methylenetetrahydrofolate reductase C677T, cytochrome P4502E1 polymorphism and environment factors in esophageal cancer in Kazakh population.

AIM: To evaluate the association and interaction of genetic polymorphisms in methylenetetrahydrofolate reductase (MTHER) and cytochrome P4502E1 (CYP4502E1), environment risk factors with esophageal cancer (EC) in Kazakh, a high EC incidence area of Xinjiang Uygur Autonomous Region, China. METHODS: A 1:2 matched case-control study was conducted with 120 cases of EC and 240 population- or hospital-based controls. The controls were matched for sex, nationality, area of residence and age within a 5-year difference. MTHER and CYP4502E1 genotypes were identified by PCR-based restriction fragment length polymorphism (RFLP). A conditional logistic regression model was established to identify risk factors. The strata method was adopted in interaction analysis. RESULTS: Low consumption of green vegetables and fresh fruits, alcohol drinking, and unsafe water (shallow well, or river) were found to be the risk factors for EC. Individuals with the MTHFR677 (C/T+T/T) genotype had a 2.62-fold (95% CI: 1.61-4.28) risk of developing EC compared with those who carried the C/C genotype. Individuals with the CYP4502E1C1/C1 genotype had a 3.00-fold (95% CI: 1.82-4.96) risk compared with those who carried the CYP4502E1 (C1/C2+C2/C2) genotype. Gene-environment interaction analysis showed that MTHFR677 gene polymorphism was correlated with consumption of green vegetables and fresh fruit, while CYP4502E1 C1/C1 was correlated with alcohol drinking and unsafe drinking water. MTHFR and CYP4502E1 analysis of gene-gene interaction showed that individuals with the MTHFR677 (C/T+T/T) and CYP4502E1C1/C1 genotypes had a 7.41-fold (95% CI: 3.60-15.25) risk of developing EC compared with those who carried the MTHFR677C/C and CYP4502E1 RsaI C1/C2+C2/C2 genes, and the interaction rate was higher than that of the two factors alone. CONCLUSION: Low consumption of green vegetables and fresh fruits, alcohol drinking, and unsafe water (shallow well, or river) and polymorphisms in MTHFR and CYP4502E1 genes are important risk factors for EC. There is a synergistic interaction among polymorphisms in MTHFR and CYP4502E1 genes and environment factors. MTHFR and CYP4502E1 genes can be used as biomarkers for prevention of EC in Kazakh, Xinjiang Uygur Autonomous Region, China.

[Study on the ingestion of folate and polymorphism of MTHFR C677T with esophageal cancer in Xinjiang Kazakh].

OBJECTIVE: To study the relationship between esophageal cancer (EC) and the ingestion of folate, methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms in Kazakh area, Xinjiang. METHODS: A 1:2 matched case-control study was adopted. 120 cases diagnosed as esophageal cancer were collected with 240 population-based and hospital-based controls were selected by the same sex, same nationality and each pair's ages were permitted to differ within 5 years. MTHFR genotypes were detected by polymeerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and the conditional logistic regression model was performed in this study. RESULTS: Data showed that the ingestion of folate was related to EC in Kazakh (chi2 = 7.868, nu = 1, P < 0.01) with OR: 0.519 (95% CI:0.329-0.821) while more folate intake appeared to be the protective factor of EC in Kazakh. The MTHFR C677T genotype frequencies of EC group was different from the control group (chi2 = 15.823, nu = 1, P < 0.01). The individuals with 677CT, TT genotype had a 2.613-fold (95% CI: 1.628-4.194) increased risk of developing EC, compared to those who had 677CC genotype. Data from Interaction Analysis showed that more folate intake could reduce the incidence of esophageal cancer to the individuals who carried the MTHFR 677CT or TT genotypes. RESULTS: from multivariate conditional logistic regression analysis showed that: unsanitary drinking water, irregular eating, prefer eating peppery food, engorgement, crusted rice or wheat, having history of stomach or esophagus illness, carrying MTHFR 677CT or TT genotypes were risk factors of esophageal cancer while taking in more folate was the protective factor of EC. CONCLUSION: Lacking of folate intake were mainly risk factor and the polymorphisms of MTHFRC677T gene were susceptibility factor of esophageal cancer in Kazakh in Xinjiang.