[Show abstract][Hide abstract]ABSTRACT: To identify the interactions of susceptive genes with related to the genetic polymorphism of metabolism enzymes (CYP1A1, GSTT1 and GSTM1) and their impacts on the risk of breast cancer; and to test the feasibility of using Multifactor Dimensionality Reduction (MDR) model in analyzing gene-gene interactions.
A paired case-control study, matched by age and menstruate state, was conducted. From December 2003 to September 2004, 78 pairs of people with and without breast cancers were investigated. The variant genotypes of CYP1A1 Msp I and GSTT1/M1 were identified by PCR-RFLP and multiplex PCR assays. The gene-gene interactions were analyzed with the MDR model. Based on the result of the MDR model, a conditional logistic regression model was constructed as the final cause-effect interpretative model.
The interaction between CYP1A1 Msp I variant genotype (vv) and GSTT1 null genotype gave the best MDR model with statistical significance (Sign Test, P = 0.05). The model Testing Balance Accuracy was 0. 5920. The Cross-Validation consistency was 10/10. The final conditional logistic regression based on the MDR model showed that passive smoking, abortion and gene-gene interaction were risks of breast cancers, with an OR (95% confidence interval) of 12.234 (1.7459-85.7279), 4.554 (1.3250-15.6507) and 9.597 (1.5783-58.3599), respectively.
The MDR model may be an effective method for estimating risks of breast cancers due to gene-gene and gene-environment interactions. The gene-gene interaction with related to the genetic polymorphism of metabolism enzymes (CYP1A1 and GSTT1) may increase the risk of breast cancer by disturbing the metabolism of estrogen.
Article · Oct 2008 · Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition
[Show abstract][Hide abstract]ABSTRACT: To study the contents of organochlorine pesticides in human bodies and residues in serum of populations with non-occupational exposure as well as to study the relationship between organochlorine pesticides in foodstuff and residues levels in serum.
A cross-section study was conducted. 107 men and 142 women who were all healthy and living in the communities were investigated from Mar. 2004 to Jul. 2004. Level of daily food exposure was estimated through questionnaires while DDTs and HCHs serum levels were detected by EC-ECD. The relationship between organochlorine pesticides contents in foods and residues in serum were analyzed by ridge regression.
Fresh fish was positively correlated to men's serum level of beta-HCH and p,p'-DDT (beta = 0.1266 and beta = 0.0595) while vegetables and fruits were negatively correlated to women's serum level of beta-HCH (beta = -0.1066). Soybean was negatively correlated to women's serum level of p,p'-DDE and p,p'-DDT (beta = -0.0965 and 3 = -0.0581). Alcohol consumption was negatively correlated to men's serum level of beta-HCH and p,p'-DDE and women's serum level of p,p'-DDE (beta = -0.1315, beta = -0.1599 and P = -0.1128).Salted meat was negatively correlated to men's serum level of beta-HCH and p, p'-DDT (P = -0. 066 and P = - 0.0569).
In this study, fresh fish might increase the body burden of organochlorine pesticides and residues while alcohol might promote the excretion of organochlorine pesticides. Pickled meat and vegetal foodstuff might contain low-level of organochlorine pesticides and residues.
Article · Mar 2007 · Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi
[Show abstract][Hide abstract]ABSTRACT: To study the potential effect of gene-environment interaction between CYP1A1 and serum dichlorodiphenyldichloroethane (DDT) levels on the risk of breast cancer in women, in China.
A case-control study was conducted. From Dec. 2003 to Sep. 2004, 104 women with histologically confirmed breast cancers and 154 noncancerous controls from a community were enrolled in this study. Risk factors information of breast cancer was investigated by a questionnaire. Serum p, p'-dichlorodiphenyldichloroethane (p, p'-DDT) and 1, 1-dichloro-2, 2-bis (p-chlorophenyl) ethylene (p, p'-DDE) levels were tested by GC-ECD. CYP1A1 m2 gene type was tested by allele special-PCR method.
Serum DDT levels of case and control were (36.90 +/- 79.41) ng/ml and (50.60 +/- 150.70) ng/ml respectively. Serum 1, 1-dichloro-2, 2-bis (p-chlorophenyl) ethylene (p, p'-DDE) levels of case and control were (7.43 +/- 11.10) ng/ml and (8.96 +/- 11.30) ng/ml respectively. No statistically significant differences were found between the two groups with geometric mean t-test (P > 0.05). Compared with women who had homozygous wild-type CYP1A1 m2 genotype, significantly increased risks of breast cancer were found for women with the CYP1A1 m2 homozygous variant genotype [odds ratio (OR) = 2.61, 95% confidence interval (CI): 1.00 - 6.80]. Among premenopausal women, compared with women with homozygous wild-type of CYP1A1 genotype (Ile/Ile) and low serum DDT level (DDT serum level < or = 42.93 ng/ml), women with at least one variant allele of CYP1A1 m2 genotype and high serum DDT level (DDT serum level > or = 42.93 ng/ml) had higher risk of breast cancer (OR = 4.35, 95% CI: 1.140 - 16.950).
CYP1A1 m2 genetic polymorphism was associated with increased risk of female breast cancer while DDT exposure might have increased the risk of breast cancer among premenopausal women with CYP1A1 m2 variant genotype.
Article · Apr 2006 · Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi