title: An intron 4 VNTR polymorphism of the endothelial nitric oxide synthase gene is associated with early-onset colorectal cancer.
abstract: Endothelial-derived nitric oxide, which is produced by endothelial nitric oxide synthase (eNOS), may play an important role in colorectal carcinogenesis. However, the putative contribution of common eNOS genetic polymorphisms to colorectal cancer risk remains unknown. We genotyped 3 polymorphisms of eNOS (T-786C, G894T, and intron4b/a) in 727 colorectal adenocarcinoma cases and 736 age- and sex-matched healthy controls in Taiwan. Genotypes of the T-786C and G894T polymorphisms were determined by fluorescence polarization assays and the 27-bp variable number of tandem repeat (VNTR) polymorphism in intron 4 (intron4b/a) was analyzed by PCR. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Among younger participants (< or =60 yrs), the intron4a variant genotype was associated with a significantly increased risk of colorectal cancer, compared with the intron4bb genotype (OR = 1.60, 95% CI = 1.04-2.46). In addition, those young individuals bearing a greater number of high-risk genotypes (OR > 1, i.e., CT+TT for T-786C, ba+aa for intron4b/a, and GG for G894T) of eNOS had a higher colorectal cancer risk (p(trend) = 0.039). Compared with younger individuals without any putative high-risk genotypes, those with 3 high-risk genotypes had a significantly greater cancer risk (OR = 1.89, 95% CI = 1.04-3.43). Our results suggest that the eNOS intron4b/a polymorphism may contribute to early-onset colorectal cancer risk in the Taiwanese population.
authors.affiliation: Department of Health Risk Management, China Medical University College of Public Health, Taichung, Taiwan. d88844003@ntu.edu.tw
authors.forename: Chih-Ching
authors.initials: CC
authors.lastname: Yeh
authors.forename: Regina M
authors.initials: RM
authors.lastname: Santella
authors.forename: Ling-Ling
authors.initials: LL
authors.lastname: Hsieh
authors.forename: Fung-Chang
authors.initials: FC
authors.lastname: Sung
authors.forename: Reiping
authors.initials: R
authors.lastname: Tang
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D017668:Age of Onset; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007438:Introns / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats / Q000235:genetics*; D052250:Nitric Oxide Synthase Type III / Q000235:genetics*; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D013624:Taiwan
chemical_list: D052250:Nitric Oxide Synthase Type III