Dietary aflatoxin B1 intake, genetic polymorphisms of CYP1A2, CYP2E1, EPHX1, GSTM1, and GSTT1, and gastric cancer risk in Korean.
OBJECTIVE
We investigated the effects of aflatoxin B1 (AFB1) intake, genetic polymorphisms of AFB1 metabolic enzymes, and interactions between the polymorphisms and intake of AFB1 with regard to the risk of gastric cancer in Korean.


METHODS
The participants in the study included 477 gastric cancer patients and 477 age- and sex-matched control subjects. Direct interviews and a structured questionnaire were used to determine the level of exposure to AFB1, and the GoldenGate assay and multiplex polymerase chain reaction were used for genotypic analyses of the cytochrome P450 1A2 (CYP1A2), cytochrome P450 1E1, epoxide hydrolase 1, and glutathione S-transferase genes.


RESULTS
The probable daily intake of AFB1 was significantly higher among gastric cancer patients than among control subjects (cases vs. controls: 1.91 ± 0.87 vs. 1.65 ± 0.72 ng/kg bw/day, p < 0.0001), and increased AFB1 intake was significantly associated with an elevated risk of gastric cancer (odds ratio 1.94; 95 % confidence interval 1.43-2.63). However, genetic polymorphisms of AFB1 metabolic enzymes were not associated with gastric cancer, with the exception of CYP1A2. Moreover, there was no interaction between AFB1 intake and the genotypes of metabolic enzymes that affect gastric cancer risk.


CONCLUSIONS
Our results suggest that dietary AFB1 exposure might be associated with a risk of gastric cancer. However, the effect of AFB1 on gastric carcinogenesis may not be modulated by genetic polymorphisms of AFB1 metabolic enzymes.
Department of Preventive Medicine and Medical Research Institute, College of Medicine, Chungbuk National University, 52 Naesudong-ro, Heungdok-gu, Cheongju, 361-763, Korea.
Sang-Yong
SY
Eom
Dong-Hyuk
DH
Yim
Yanwei
Y
Zhang
Jung-Kuk
JK
Yun
Sun In
SI
Moon
Hyo-Yung
HY
Yun
Young-Jin
YJ
Song
Sei-Jin
SJ
Youn
Taisun
T
Hyun
Joo-Seung
JS
Park
Byung Sik
BS
Kim
Jong-Young
JY
Lee
Yong-Dae
YD
Kim
Heon
H
Kim
D016604:Aflatoxin B1 / Q000008:administration & dosage* / Q000506:poisoning; D000368:Aged; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D019388:Cytochrome P-450 CYP1A2 / Q000235:genetics*; D019392:Cytochrome P-450 CYP2E1 / Q000235:genetics*; D004851:Epoxide Hydrolases / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006306:Health Surveys / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011042:Poisons / Q000008:administration & dosage; D020641:Polymorphism, Single Nucleotide; D056910:Republic of Korea; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000208:ethnology / Q000209:etiology / Q000235:genetics*
D016604:Aflatoxin B1; D019388:Cytochrome P-450 CYP1A2; D019392:Cytochrome P-450 CYP2E1; D004851:Epoxide Hydrolases; D005982:Glutathione Transferase; D011042:Poisons; C413545:glutathione S-transferase T1; C522330:EPHX1 protein, human