To evaluate the relationship between dietary folate intake and genetic polymorphisms of 5,10-methylenetetrahydrofolate reductase (MTHFR) with reference to breast cancer risk, we conducted a case–control study with 669 cases and 682 population-based controls in the Jiangsu Province of China. MTHFR C677T and A1298C genotypes were identified using PCR–RFLP (restrictrion fragment length polymorphism) methods. Dietary folate intake was assessed using an 83-item food frequency questionnaire. Odds ratios (ORs) were estimated with an unconditional logistic model. The frequencies of MTHFR C677T C/C, C/T and T/T genotypes were 32.37, 48.88 and 18.75% in cases and 37.66, 48.24 and 14.10% in controls, respectively. The difference in distribution was significant (χ2=6.616, P=0.037), the T/T genotype being associated with an elevated OR (adjusted for age, menopausal status, body mass index (BMI), income, work intensity and status of smoking and drinking) for breast cancer (1.62, 95% confidence interval (95% CI): 1.14–2.30). The frequencies of MTHFR A1298C A/A, A/C and C/C were 71.47, 27.08 and 1.44% in cases and 68.11, 30.13 and 1.76% in controls, respectively, with no significant differences being found (χ2=1.716, P=0.424). A significant inverse relationship was observed between folate intake and breast cancer risk. Compared with the lowest tertile of folate intake, the adjusted OR for breast cancer in the top tertile was 0.70 (95% CI: 0.53–0.92). However, no significant interaction was observed between folate intake and the MTHFR C677T polymorphism. Among individuals with the MTHFR A1298C A/A genotype, adjusted ORs for breast cancer were 0.89 (0.62–1.27) and 1.69 (1.20–2.36) for the second to the third tertile of folate intake compared with the highest folate intake group (tread test, P=0.0008). The findings of this study suggest that MTHFR genetic polymorphisms and dietary intake of folate may modify susceptibility to breast cancer.

个体酒精代谢的差异是由于乙醇脱氢酶(ADH)、乙醛脱氢酶(ALDH)和细胞色素P4502E1等的基因多态性所致,被摄取至肝脏的乙醇大部分被肝细胞液中的ADH催化脱氧而牛成乙醛,ALDH的主要作用是将有毒的乙醛氧化为无毒的乙酸,后者进入三羧酸循环后,最终代谢成为二氧化碳和水而排出体外,其中约有90%在肝脏中完成[1].

To evaluate the relationship between body size, physical activity and risk of breast cancer, we conducted a case-control study with 669 cases and 682 population-based controls in Jiangsu Province of China. A structured questionnaire was used to elicit detailed information. All subjects completed an in-person interview. The body mass index (BMI) was calculated based on weights and heights. Unconditional logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) as measures of risk for breast cancer. Current height, weight and weight at around age 20 years were significantly positively correlated with risk of breast cancer. Obese women (current BMI > or = 25 kg/m2) were at significantly increased risk for developing breast cancer (adjusted OR= 1.35, 95%CI: 1.01-1.81), but, between BMI at around age 20 years and risk of breast cancer showed an inverse association (P for trend = 0.001). Women who had middle physical force work were at significantly lowered OR (0.62, 95%CI: 0.41-0.93) compared with women of headwork. Using women who standing or ambulation per day less than one hour as the reference, women who standing or ambulation more than one hour had a decreased risk of breast cancer. Using women who slept less than 5 hours per day as the reference, the women who slept 5-8 hours were at significantly decreased risk of breast cancer. Women who had habit of recreational physical activity were at significantly decreased risk (adjusted OR= 0.68, 95%CI: 0.53-0.88), with an inverse association between the exercise times per week and risk of breast cancer (P for trend = 0.025). These findings support that breast cancer risk is associated with body size, and that moderate occupational and recreational physical activity has protective effects on breast cancer.

OBJECTIVE:To evaluate the relationship between dietary folate intake and genetic polymorphisms of 5, 10-methylenetetrahydrofolate reductase (MTHFR) with reference to breast cancer risk. METHODS:A case-control study was conducted with 669 cases and 682 population-based controls in Jiangsu province of China. MTHFR C677T and A1298C genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods. Dietary folate intake was assessed by using an 83-item food frequency questionnaire. Odds ratios (OR) were estimated with an unconditional logistic model. RESULTS:The frequencies of MTHFR C677T C/C, C/T and T/T genotypes were 32.37% (202/624), 48.88% (305/624) and 18.75% (117/624) in cases and 37.66% (235/624), 48.24% (301/624) and 14. 10% (88/624) in controls, respectively. The difference in distribution was significant (chi2 = 6.616, P = 0.037), the T/T genotype being associated with an elevated OR for breast cancer (1.62, 95% CI: 1.14 -2.30). The frequencies of MTHFR A1298C A/A, A/C and C/C were 71.47% (446/624), 27.08% (169/624) and 1.44% (9/624) in cases and 68.11%(425/624), 30.13% (188/624) and 1.76% (11/624)in controls,with no significant differences found (chi2 = 1.716, P= 0.424). Folate intake of cases [(263.00 +/- 137.38) microg/d] was significantly lower than that of controls [(285.12 +/- 149.61) microg/d] (t = -2. 830, P =0.005). Compared with the lowest tertile (< or = 199.08 microg/d) of folate intake, the adjusted OR for breast cancer in the top tertile (> or = 315.11 microg/d) was 0.70 (95% CI: 0.53 -0.92). Among individuals with the MTHFR A1298C A/A genotype,adjusted OR for breast cancer were 0.89 (95% CI: 0.62 - 1.27) and 1.69 (95% CI: 1.20 - 2.36) for the second to the third tertile of folate intake compared with the highest folate intake group (X2trend = 11.372, P = 0.001). CONCLUSION:The findings of the present study suggest that MTHFR genetic polymorphisms,and dietary intake of folate may modify susceptibility to breast cancer.

OBJECTIVE:To evaluate the impact of alcohol dehydrogenase-2 (ADH2) and aldehyde dehydrogenase-2 (ALDH2) polymorphisms on the susceptibility of esophageal cancer.METHODS:A case-control study including 221 cases of esophageal cancer and 191 controls was carried out in Taixing city of Jiangsu province. ADH2 and ALDH2 genotypes were tested by PCR and denaturing high performance liquid chromatography (DHPLC).RESULTS:(1) Compared with ALDH2 G/G carriers, ALDH2 A/A (OR = 5.69, 95% CI: 2.51-12.18) and ALDH2 G/A (OR = 1.70, 95% CI: 1.08-2.68) carriers showed a significantly elevated risk of developing esophageal cancer, especially among alcohol drinkers with ALDH2 A/A (OR = 8.63, 95% CI: 2.07-35.95). (2) Statistical relation was not found between ADH2 genotypes and the risk of esophageal cancer, with regard to the status of alcohol consumption. (3) Whether subjects with whatever ADH2 genotype, ALDH2 G/A or A/A carriers was found to have significantly increased the risk of developing esophageal cancer, with ALDH2 A/A carriers appeared having higher esophageal cancer risk than those ALDH2 G/A carriers. (4)Compared those non-drinkers with both ALDH2 G/G and ADH2 A/A, drinkers with ALDH2 G/A or A/A and ADH2 G/A or G/G genotypes showed a significantly elevated risk of developing esophageal cancer (OR = 8.36, 95% CI: 2.98-23.46).CONCLUSION:These results revealed that it was not ADH2 but ALDH2 polymorphisms and drinking alcohol had a significant interaction with the development of esophageal cancer, suggesting that in order to help lowering the risk of esophageal cancer, individuals who are carrying ALDH2 A/A or G/A genotypes should be encouraged to reduce their consumption of alcohols.

OBJECTIVE:To investigate the relationship of alcohol dehydrogenase-2 (ADH2) and aldehyde dehydrogenase-2 (ALDH2) genotypes as well as alcohol drinking to the susceptibility of primary hepatocellular carcinoma (HCC). METHODS:A case-control study including 208 cases of HCC and 208 controls matched with sex, age and residential area was carried out in Taixing city of Jiangsu province, China. Blood samples were collected and tested for ADH2 and ALDH2 genotypes by PCR-RFLP method. RESULTS:There were no significant differences in the frequency of either ADH2 or ALDH2 genotypes between cases and controls. Compared with no-drinkers possessing ALDH21*1 genotypes, drinkers with ALDH21*2 or ALDH22*2 genotypes and cumulative amount of alcohol consumption >3 (Kg * years) were at a significantly higher risk of developing HCC (OR=3.30, 95%CI: 1.24-8.83). In contrast, there was no significant difference in cancer risk between no-drinkers with ADH21*1 and drinkers with ADH2 1*2 or ADH22*2 genotypes. A dose-dependent positive result was found (P=0.044) between cumulative amount of alcohol consumption and the risk of HCC in individuals carrying ALDH21*2 or ALDH22*2 genotypes. Drinkers with cumulative amount of alcohol consumption >3 (Kg * years) who possessed both inactive ALDH2 (ALDH21*2 or ALDH22*2) and inactive ADH (ADH21*2 or ADH22*2) genotypes were not at a significantly higher risk of HCC (adjusted OR=4.26, 95%CI: 0.63-29.08) compared to no-drinkers possessing ADH21*1 and ALDH21*1 genotypes. Compared with individuals possessing ALDH21*1, with negative HBsAg and cumulative amount of alcohol consumption 3 (Kg * years) had a significantly higher risk of HCC (OR=49.71, 95%CI: 5.51-448.96). CONCLUSION:These results revealed that it was not ADH2 but ALDH2 polymorphisms that had a significant interaction with heavy alcohol consumption in the development of HCC. This result suggests that to help lower their risk for HCC , persons with ALDH21*2 or ALDH22*2 genotypes should be encouraged to reduce their consumption of alcoholic beverages.

OBJECTIVE:To study the relation-ship between genetic polymorphisms of methylenetetrahydrofolate reductase(MTHFR) C677T or A1298C and the susceptibility of colorectal cancer.METHODS: A case-control study was conducted with 315 cases of colorectal cancer and 371 population-based controls in Jiangsu Province,China.The epidemiological data were collected,and DNA of peripheral blood leukocytes was obtained from all of the subjects.MTHFR C677T and A1298C genotypes were detected by PCR-RFLP.RESULTS: 1)When men and women were assessed together,the frequencies of the MTHFR C677T and A1298 genotypes or their alleles were not significantly different between the controls and colon cancer or rectal cancer cases.No significant relation was observed between MTHFR C677T or A1298C polymorphisms and colon or rectal cancer susceptibility.2)Among males,individuals who had MTHFR C677T T/T genotype were at a significantly higher risk of developing colon cancer(sex-,age-,residence-,smoking,alcohol drinking-,tea consumption-adjusted OR=2.15,95%CI: 1.07-4.33) compared with those who had C677T C allele.Individuals who had C677T T/T and A1298C A/A genotypes were at an increased risk of developing colon cancer(adjusted OR=2.64,95%CI: 1.20-5.81) compared with those with C677T C allele and A1298C A/A genotypes among males.On the contrary,individuals who had C677T T/T and A1298C A/A genotypes were at an decreased risk of developing rectal cancer(adjusted OR=0.47,95%CI: 0.22-1.03).CONCLUSION: Polymorphisms of the MTHFR C677T can influence susceptibility to colon or rectal cancer,and there is a synergic effect between MTHFR A1298C A/A and C677T T/T genotypes among males.

The 5,10-methylenetetrahydrofolate reductase (MTHFR) enzyme plays an important role in folate metabolism and determines the balance between the different forms of folate for DNA synthesis and DNA methylation (Bailey et al, 1999; Fodinger et al, 2000). MTHFR catalyzes the reduction of 5,10methylenetetrahydrofolate to 5-methyltetrahydrofolate, a substrate for the conversion of homocysteine to methionine. The latter is a precursor to Sadenosylmethionine, which is an important methyl donor for DNA methylation. In addition, 5,10-methylenetetrahydrofolate, a substrate of MTHFR, is also required for thymidylate and purine synthesis. Folate derivatives are essential for normal synthesis

Objective: To study the relationship between genetic polymorphism of cytochromes P4502E1 RsaⅠand smoking,alcohol drinking habit with the susceptibility of rectal cancer. Methods:A case-control study was conducted with 210 cases of rectal cancer and 439 population-based controls in Jiangsu Province, China. The epidemiological data were collected, and DNA of peripheral blood leukocytes was obtained from all the subjects. CYP2E1 RsaⅠgenotypes were detected by PCR-RFLP. Results:The frequencies of CYP2E1 RsaⅠ c1/c1,c1/c2 and c2/c2 genotypes were 58.4%, 34.0% and 7.7% in rectal caner cases, compared with 61.4%, 35.6% and 3.0% in controls(χ2 = 7.07, P = 0.029). Individuals with CYP2E1 RsaⅠ c2/c2 genotype were at an increased risk of rectal cancer(adjusted for age, sex and status of the smoking and alcohol drinking,OR = 1.64, 95% CI:1.12-2.41) compared with those with CYP2E1 RsaⅠ c1/c1 genotype. Individuals who had alcohol drinking habit were at an increased risk of rectal cancer(adjusted OR = 2.08, 95% CI:1.36-3.19), whereas smoking was not associated with risk of rectal cancer. There was a significantly cooperated effect between CYP2E1 RsaⅠ polymorphism and alcohol drinking habit in the risk of rectal cancer. The risk of rectal cancer of individuals with CYP2E1 RsaⅠ c2/c2 genotypes and drinking habit increased 5.75 times(95%CI:1.65-20.05). Conclusion:Polymorphisms of the CYP2E1 RsaⅠ and acohol drinking have effects on rectal cancer and have significantly synergic effect.

Objective To evaluate the relationship between the genetic polymorphisms of alcohol dehydrogenase 2 (ADH2) and aldehyde dehydrogenase 2 (ALDH2) and the occurrence of colorectal cancer in Chinese males.Methods We conducted a case-control study of 190 cases of colorectal cancer (CRC) and 222 population-based controls in Jiangsu Province,China.ADH2 Arg47His (G—A) and ALDH2 Glu487Lys (G—A) genotypes were identified by PCR and denaturing high-performce liquid chromatography (DHPLC).Logistic regression was used to calculated Odds Ratios (OR) and 95% confidence intervals (95% CI).Results The ADH2 A/A and ALDH2 G/G genotype showed moderately increased risk for CRC,the age- and smoking-adjusted OR for ADH2 A/A genotype relative to G/A and G/G was 1.61 (95% CI: 1.09~2.38),and the adjusted OR for ALDH2 G/G genotype relative to G/A and A/A was 1.79 (95% CI: 1.19~2.68).Significant gene-gene and gene-environment interactions between ADH2,ALDH2 and alcohol drinking were observed regarding colorectal cancer risk.As compared with the individuals with the ADH2 G and ALDH2 A alleles,the individuals with the ADH2 A/A and ALDH2 G/G genotypes had a significantly increased OR (3.05,95%CI: 1.67~ 5.57).The OR for CRC among alcohol drinkers with ADH2 A/A genotype was markedly increased to 3.44 (95%CI: 1.84~6.42) compared with non-drinkers with ADH2 G allele.The OR for CRC among alcohol drinkers with ALDH2 G/G genotype was markedly increased to 2.70 (95%CI: 1.57~4.66) compared with non-drinkers with A LDH2 A allele.Conclusion The results show that the genetic polymorphisms of the ADH2 and ALDH2 can influence susceptibility of colorectal cancer,and also revealed a significant gene-gene and gene-environment interactions between alcohol drinking and the ADH2 and ALDH2 polymorphisms regarding colorectal cancer risk in Chinese males.

OBJECTIVE:To study the relationship between genetic polymorphisms of growth hormone 1 (GH1) T1663A and the susceptibility of colorectal cancer (CRC). METHODS: A case control study was conducted with 315 patients with CRC and 439 population-based controls in Jiangsu Province, China. The epidemiological data were collected, and DNAs of peripheral blood leukocytes were obtained from all of the subjects. GH1 genotypes were detected by PCR-RFLP. RESULTS: 1) The frequencies of the GH1 T/T, T/A and A/A genotypes were 42.2%, 46.7% and 11.1% in colorectal cancer cases, and 38.1%, 45.9% and 16.0% in controls, respectively. Compared with individuals who had GH1 T/T genotype, individuals who had GH1 A/A genotype were at a decreased risk of developing colorectal cancer (sex-, age-, smoking-and alcohol drinking-adjusted OR=0.88, 95%CI: 0.78-0.99, P=0.029). 2) Smoking was not associated with the risk of colorectal cancer, whereas alcohol drinking was associated with the increased risk of colorectal cancer (sex-, age-, smoking- and GH1 genotype-adjusted OR=1.96, 95%CI: 1.34-2.86). 3) Among non-smokers, individuals who had GH1 A/A genotype were at a decreased risk of developing colorectal cancer (sex-, age-adjusted OR=0.50, 95%CI: 0.27-0.93) compared with individuals who had GH1 T allele. Among non-drinkers, individuals who had GH1 A/A genotype also were at a decreased risk of developing colorectal cancer (sex-, age-adjusted OR=0.56, 95%CI: 0.32-0.99) compared with individuals who had GH1 T allele. CONCLUSION: The results show that the GH1 gene T1663A polymorphism can influence susceptibility of colorectal cancer, particularly in non-smokers or non-drinkers.

BACKGROUNDAIM: To analyze the genotype frequency of alcohol dehydrogenase-2(ADH2),and evaluate the relationship between ADH2polymorphism and drinking behavior in Chinese.MATERIAL AND METHODS: Epidemiological data were collected from207healthy persons in Taixing city of Jiangsu province,China,and ADH2genotypes were determined by polymerase chain reattion restriction-fragment length polymorphism,(PCR -RFLP)method. RESULTS: The frequencies ofADH 1ˇ12 , ADH 1ˇ22 andADH 2ˇ22 genotypes were12.6%,46.8%and40.6%respectively.Significant differences were found in the frequency of ADH2genotypes between drinkers and no-drinkers.Cumularivy amounts of alcohol consumption were found statistically different among drinkers with different ADH2genotypes. CONCLUSION: Drinking behavior was influenced by the individual genotypes of ADH2.

Objective The relation between methylenetetrahydrofolate reductase (MTHFR) C677T genotypes?dietary habits and the risk of stomach cancer (SC) was studied. Methods A case-control study was conducted with 107 cases of SC and 200 population-based controls in Chuzhou district, Huaian, Jiangsu province, China. The epidemiological data were collected, and DNA of peripheral blood leukocytes was obtained from all of the subjects. MTHFR genotypes were detected by PCR-RFLP. Results (1) The prevalence of the MTHFR C /T or T /T genotypes was found to be significantly different between controls (68.5%) and SC cases (79.4%, P = 0.0416 ), the increased risk had an adjusted OR of 1.79 (95% CI: 1.01-3.19). (2) Among subjects who had low intake of garlic or Chinese onion, MTHFR C /T or T /T genotypes significantly increased the risk of developing SC. Among non tea-drinkers or among subjects who had frequent intake of meat, the carriers of the MTHFR C /T or T /T genotypes had a higher risk of SC than individuals with C /C type MTHFR . Conclusion The polymorphism of MTHFR C677T was associated with risk of developing SC, and that individuals with different genotypes may have different susceptibilities to SC, based on environmental factors.

OBJECTIVE To investigate the relationship between polymorphisms of methylenetetra-hydrofolate reductase gene 1298A-->C (MTHFR 1298A-->C) and its susceptibility of esophageal cancer (EC). METHODS We conducted a case-control study with 141 cases of EC and 228 population-based controls in Huaian city of Jiangsu province, China. Epidemiological data were collected, and DNA of peripheral blood leukocytes was obtained from all of the subjects. MTHFR genotypes were identified by polymerase chain reaction. RESULTS (1) The frequency of MTHFR 1298AA, AC and CC genotype were 63.8%, 34.0% and 2.1% in EC and 71.9%, 28.1% and 0.0% in controls, respectively (chi(2)(MH) = 6.69, P = 0.035). The frequency of the MTHFR 1298C allele was 0.19 for EC and 0.14 for controls. (2) Individuals having MTHFR 1298C allele and smoking habit were at a significantly higher risk of developing EC (adjusted OR = 3.48, 95% CI: 1.57 - 7.71) compared with those who having AA genotype but no smoking habit. Individuals having MTHFR 1298C allele and habit of frequent alcohol drinking were at an increased risk of developing EC (adjusted OR = 2.91, 95% CI: 1.20 - 7.08) compared with those with AA genotype and low consumption of alcohol. Individuals having MTHFR 1298C allele but no habit of tea drinking had a 3.52-fold (95% CI: 1.64 - 7.54) increased risk of developing EC compared with tea drinkers with AA genotype. As compared with subjects having AA genotype, low consumption of alcohol, no smoking habit but having habit of drinking tea, the individuals having 1298C allele, habits of frequent alcohol drinking, smoking but no habit of tea drinking had a 12.64-folds (95% CI: 1.39 - 114.65) increased risk of developing EC. CONCLUSION Results in the present study suggested that there was a coordinated effect between MTHFR 1298 genotypes and habits of smoking, alcohol drinking and tea consumption in the development of EC.

OBJECTIVE: To evalute interactions between dietary habits and polymorphisms in the 3′-untranslated region (3′-UTR) of thymidylate synthase gene (TS) in the development of gastric cardia cancer. METHODS:We conducted a case-control study with 89 cases of gastric cardia cancer and 223 population-based controls in Huaian City of Jiangsu Province, China. The epidemiological data were collected, and DNA of peripheral blood leukocytes was obtained from all of the subjects. TS genotypes were detected by PCR-RFLP method. RESULTS: No significant differences were found between the cases and the controls according to their frequencies of TS 3′-UTR genotypes. Individuals having TS -6 bp/-6 bp genotype and smoking habit were at a significant higher risk for gastric cardia cancer (adjusted OR=3.99,95% CI:1.51-10.50) compared with those having +6bp alleles and no smoking habit. Individuals having TS -6 bp/-6 bp genotype and habit of frequent alcohol drinking were at an increased risk of developing gastric cardia cancer (adjusted OR=3.22,95% CI: 1.21-8.55) compared with those with +6 bp alleles and low consumption of alcohol.Compared with individuals having +6bp alleles and habit of tea drinking, those with TS -6bp/-6bp genotype but without habit of tea drinking had a significant higher risk for gastric cardia cancer(adjusted OR=6.14,95% CI: 2.39-15.77). CONCLUSIONS:Based on environmental factors, different genotypes in TS 3′-UTR may have different susceptibility to gastric cardia cancer.

To investigate the relationship between methylennetetrahydrofolate reductase C677T(MTHFR) genotypes,dietary habits and the risk of gastric cardia cancer. A case-control study with 89 cases of gastric cardia cancer and 223 population-based controls in Huaian city of Jiangsu province was conducted.The dietary habits data were collected.MTHFR genotypes were detected by PCR-RFLP method.The correlations were analyzed by using SAS or EPI-Info software.(1)Males with smoking habit and females with drinking habit were at a significantly higher risk of developing gastric cardia cancer, tea drinking was a protective factor for developing gastric cardia cancer. (2) The prevalence of the MTHFR C/T+T/T genotypes was found to be significantly different between gastric cardia cases (82.0%) and controls (72.3%), the increased OR was 2.05 (95%CI 1.05~2.03) after adjustment for gender, age, smoking, alcohol drinking, tea drinking and intaking of raw vegetables, meat and soybean production. (3) There was a significant interaction among habits of smoking,drinking and no tea drinking and MTHFR677 C/T+T/T genotypes for gastric cardia cancer.[Conclusion]The polymorphisms of MTHFRC677T is associated with risk of developing gastric cardia cancer,and influences the correlation between the habits of smoking ,alcohol drinking, tea drinking and the developing of gastric cardia cancer.

To explore the relationship between alcohol drinking habit,hepatitis B surface antigen (HBsAg) and hepatocellular carcinoma (HCC) in Taixing City.A case-control study including 208 cases with HCC and 208 controls matched with sex, age and resident area was carried out in Taixing City of Jiangsu Province,China.Blood samples were collected and tested for serum HBsAg by ELISA.The Epi-Info Software and Statistical Analysis System Software(SAS) were used for data analysis.The positive rate of serum HBsAg in HCC group was much higher than that in controls (72.12% vs 22.12%, P0.0001). Univariate analysis showed that HBsAg positive, chronic hepatitis, hepatocirrhosis and schistosomiasis could increase the risk of HCC.Multi-rariate analysis with unconditional Logistic regression showed that HBsAg positive and chronic hepatitis were also the significant risk factors of HCC(OR=7.317 and 6.694).Both HBsAg positive and habitual alcohol drinking were associated with a significantly higher risk of HCC.[Conclusion]HBsAg positive and the history of liver diseases are the important risk factors of HCC in Taixing City.HBV infection and alcohol intake have synergism in carcinogenesis for HCC.

Thymidylate synthetase (TS) and methylenetetrahydrofolate reductase (MTHFR) are major enzymes in the metabolism of folates, involved in DNA 'breaks', instability and hypomethylation. To investigate the possible relations between the TS 3'-UTR and MTHFR C677T polymorphisms and environmental factors impacting on risk of esophageal and stomach cancers, we conducted a case-control study in a high incidence region of China for these cancers. We recruited 138 esophageal and 155 stomach cancer cases, and 223 controls. The TS 3' -UTR and MTHFR C677T genotypes were detected by RFLP assay, using PCR products. The frequency of the -6 bp homozygous TS 3' -UTR genotype was 37.7 % in controls, higher than in Caucasians, although the present distribution was not in Hardy-Weinberg equilibrium. Ever-smoking with the -6 bp/-6 bp TS genotype elevated the ORs (2.61, 1.24-5.49; 3.54, 1.60-7.82) for cases of esophageal and stomach cancers, respectively, when compared with never-smoking with the +6 bp/+6 bp and +6 bp/-6 bp genotypes. No combination between the TS and MTHFR genotypes gave increased ORs. The present results suggest that TS polymorphism may modify the risk of esophageal and stomach cancer with smoking, pointing to the necessity for further investigations with information on folate and methionine intake with a larger population.

OBJECTIVE:To evaluate the relationship among CYP2E1, habit of alcohol drinking and hepatocellular carcinoma. METHODS: A case-control study was conducted with 208 hepatocellular carcinoma cases and 208 normal residents as controls in Taixing City of Jiangsu Province, China. CYP2E1 genotypes were assayed by PCR-RFLP.RESULTS:The frequencies of C1/C2+C2/C2 genotypes of CYP2E1 in the hepatocellular carcinoma cases and controls were 41.06% and 37.02% respectively.No difference was found between them;and no interaction between CYP2E1 RsaⅠ polymorphism and hepatocellular carcinoma was found.CONCLUSION:Polymorphism of a single gene CYP2E1 is not associated with the risk of hepatocellular carcinoma in Taixing City.

Objective To investigate the relationship between polymorphisms of methylennetetrahydrofolate reductase A1298C (MTHFR) and susceptibility of gastric cancer.Methods 156 patients with gastric cancer and 228 healthy subjects in Huaian city of Jiangsu province were comparatively investigated.The epidemiological data were collected,and DNA of peripheral blood leukocytes was obtained from all of the subjects.MT HFRAl298C genotypes were detected by PCR-RFLP method.Results (1) The frequency of METHFRAl298C variantgenotypes (AC+CC) in patients and control group was 28.1% and 33.4% respectively,there was no significant difference between the two groups.(2) There was a significant interaction among habits of smoking and alcohol drinking and MTHFRAl298C variant genotype in gastric cancer,and this interaction fitted multiplicative model.(3) An increase of gastric cancer risk was found in individuals who had no habit of tea drinking.Conclusion There is a interaction between MTHFRAl298C genotypes and habits of smoking and alcohol drinking in developing gastric cancer.