Silva T D, Felipe A V, Pimenta C A M, Barão K, Forones N M
Setor de Oncologia, Disciplina de Gastroenterologia, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
Genet Mol Res. 2012 Sep 3;11(3):3138-45. doi: 10.4238/2012.September.3.2.
We investigated a possible association between alcoholism, cigarette smoking, obesity and CYP2E1 RsaI and 96-bp insertion genetic polymorphisms with risk for colorectal cancer (CRC). Patients with CRC (70 women and 61 men) were matched for gender and age to 206 healthy controls. The mean age of the two groups was 62 years. Meat intake, cigarette smoking and alcohol drinking were assessed using a specific frequency questionnaire. The body mass index was also calculated. DNA was extracted from peripheral blood; RsaI polymorphism genotypes were evaluated by PCR-RFLP and 96-bp insertion genetic polymorphisms were evaluated by specific primers. The distributions of CYP2E1 RsaI c1/c1, c1/c2 and c2/c2 genotypes were 90.2, 9.2 and 0.6%, respectively, in controls and 83.9, 13.7 and 2.4% in CRC cases. Allele c2 was associated with increased risk for CRC [odds ratio (OR) = 1.88, 95% confidence interval (95%CI) = 1.02-3.45]. The CYP2E1 RsaI c2/c2 genotype was associated with an increased risk for rectal cancer (OR = 3.23, 95%CI = 1.26-9.03). The 96-bp insertion was slightly more frequent in the CRC group (9.3 vs 11.4%, P = 0.19), especially in females (6.4 vs 11.5%, P = 0.34). Smoking, alcohol drinking or high intake of red meat and CYP2E1 polymorphisms were not associated with increased risk for CRC. The 96-bp insertion was marginally more frequent (P = 0.07) in undernourished CRC subjects. We concluded that the risk for CRC is higher among individuals with allele c2. The CYP2E1 RsaI c2/c2 genotype was associated with an increased risk for rectal cancer.
我们研究了酗酒、吸烟、肥胖与CYP2E1 RsaI及96-bp插入基因多态性与结直肠癌（CRC）风险之间的可能关联。CRC患者（70名女性和61名男性）按性别和年龄与206名健康对照进行匹配。两组的平均年龄为62岁。使用特定频率问卷评估肉类摄入量、吸烟和饮酒情况。还计算了体重指数。从外周血中提取DNA；通过PCR-RFLP评估RsaI多态性基因型，通过特异性引物评估96-bp插入基因多态性。在对照组中，CYP2E1 RsaI c1/c1、c1/c2和c2/c2基因型的分布分别为90.2%、9.2%和0.6%，在CRC病例中分别为83.9%、13.7%和2.4%。等位基因c2与CRC风险增加相关[比值比（OR）=1.88，95%置信区间（95%CI）=1.02 - 3.45]。CYP2E1 RsaI c2/c2基因型与直肠癌风险增加相关（OR = 3.23，95%CI = 1.26 - 9.03）。96-bp插入在CRC组中略为常见（9.3%对11.4%，P = 0.19），尤其是在女性中（6.4%对11.5%，P = 0.34）。吸烟、饮酒或红肉高摄入量与CYP2E1多态性与CRC风险增加无关。96-bp插入在营养不良的CRC患者中略为常见（P = 0.07）。我们得出结论，携带等位基因c2的个体患CRC的风险更高。CYP2E1 RsaI c2/c2基因型与直肠癌风险增加相关。
