CYP1A2*1F Gene Variant,Alkaline Salt Tea Intake and Risk of Esophageal Squamous Cell Carcinoma

Unlike many other cancers, the relationship of CYP1A2*1F (rs762551) polymorphism with esophageal squamous cell carcinoma (ESCC) risk has not been assessed so far. To evaluate its association with ESCC, we conducted a case control study in Kashmir, India, a high risk region. We recruited 404 histopathologically confirmed ESCC cases and 404 controls, individually matched for sex, age and residence to the respective cases. Information was obtained on dietary, lifestyle and environmental factors in face to face interviews using a structured questionnaire from each subject. Genotypes were analyzed by polymerase chain reaction, restriction fragment length polymorphism and sequencing randomly selected samples. Conditional logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs). We found that mutant genotype (AA) of CYP1A2*1F polymorphism was associated with ESCC risk (OR = 3.11; 95% CI: 1.72–5.36). A very strong ESCC risk was observed in subjects who drank >1250 ml of salt tea daily and harbored mutant genotype of CYP1A2*1F (OR = 14.51; 95% CI: 5.33–39.47). The study indicates that CYP1A2*1F polymorphism is associated with ESCC risk and the risk is modified in salt drinkers. However, more replicative and mechanistic studies are needed to substantiate the findings.     

细胞色素P4501A1基因多态性与食管癌易感性关系的Meta分析

目的 探讨细胞色素P4501A1(CYP1A1)MspI和Ile/Val位点基因多态性与食管癌发生的关系.方法 采用Meta分析方法,对国内外1997-2008年采用病例对照方法研究CYP1A1MspI和Ile/Val基因多态性与食管癌发生关系的16篇(MspI 8篇,Ile/Val 14篇)文献,采用显性模型(即突变基因型与野生型比较)进行综合定量分析,然后按病理分型(鳞癌/腺癌)分亚组进行分析.结果 综合分析CYP1A1 MspI突变基因型(TC+CC)与食管癌发生无统计学关联(OR=1.17,95%CI:0.82～1.66),亚组分析亦未发现CYP1A1 MspI突变基因型与食管鳞癌(OR=1.17,95%CI:0.82～1.69)和食管腺癌(OR=1.39,95%CI:0.67～2.09)的统计学关联;携带CYP1A1突变基因型(Ile/Val+Val/Val)的个体发生食管癌的危险性是野生型的1.39倍(OR=1.39,95%CI:1.07～1.80);亚组分析显示突变基因型与食管鳞癌发生的易感性相关但与食管腺癌无关联,OR值分别为1.43(95%CI:1.07～1.91)和1.20(95%CI:0.62～2.30).结论 CYP1A1 Ile/Val位点突变基因型可增加食管鳞癌发生的危险性,CYP1A1 MspI位点基因多态性与食管癌无关联.     

Association of Genetic Variants of CYP2C19 and CYP2D6 with Esophageal Squamous Cell Carcinoma Risk in Northern India,Kashmir

Genetic polymorphism in xenobiotic metabolizing enzymes (XMEs) is associated with various malignancies. However, the association of esophageal cancer with XMEs is mixed. The current study was aimed to explore the association of genetic polymorphisms of cytochrome (CYP) 2C19 and CYP2D6 genotypes with esophageal squamous cell carcinoma (ESCC) risk in Kashmir, India. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing methods were used for genotyping of 492 ESCC cases and equal number of individually matched controls. Conditional logistic regression models were used to assess odds ratios (ORs) and 95% confidence intervals. Increased ESCC risk was observed in subjects with variant genotypes of CYP2C19 (OR = 3.3) or CYP2D6 (OR = 2.1) and risk was higher (OR = 4.6) in subjects who harbored both the genotypes. Almost same but higher risk turned when subjects were smokers and carried a variant genotype of CYP2C19 (OR = 4.4) or CYP2D6 (OR = 4.7). Risk was appreciably increased in subjects who had family history of any cancer and also harbored a variant genotype of either CYP2C19 (OR = 15.5) or CYP2D6 (OR = 9.7). Subjects harboring a variant genotype of CYP2D6 showed an added risk when they used biomass as fuel (OR = 4.6). In conclusion, variant genotypes of CYP2C19 and CYP2D6 are associated with an increased risk of ESCC.     

谷胱甘肽转硫酶M1和T1基因型与食管癌危险性:病例-对照研究

为探讨参与致癌物代谢的谷胱甘肽转硫酶（ＧＳＴ）Ｍ１和Ｔ１基因多型性与食管癌危险性的关系，以病例－对照分子流行病学方法，分析食管癌高发区河南林县的食管癌、食管上皮重度增生病例和性别、年龄配对的正常对照者（各４５例）的ＧＳＴＭ１和ＧＳＴＴ１基因型分布的差异。基因组ＤＮＡ来自研究对象的食管外科手术标本或细胞学检查获得的食管上皮细胞，以多重聚合酶链反应方法进行基因分型。结果：食管癌、食管上皮重度增生病例和     

Metabolic gene polymorphisms and risk of dysmenorrhea

We conducted a molecular epidemiologic study in rural China to investigate the association of the cytochrome P450 2D6 (CYP2D6) and glutathione S-transferase Mu (GSTM1) polymorphisms with dysmenorrhea. This report includes 435 subjects, 129 with and 306 without any history of dysmenorrhea, who did not smoke or drink alcohol. We obtained information on dysmenorrhea and major covariates by questionnaire interview. We used categorical methods and logistic regression models to evaluate the individual and combined associations of CYP2D6 and GSTM1 polymorphisms with dysmenorrhea and its subgroups, occasional (N = 70) and recurrent (N = 59), with adjustment for age, education, occupation, passive smoke exposure, age of menarche, parity, contraceptive method, height, and body mass index. Both variant CYP2D6 and GSTM1 genotypes were associated with increased risk of recurrent dysmenorrhea [for CYP2D6, odds ratio (OR) = 1.7 and 95% confidence interval (95% CI) = 0.9-3.1; for GSTM1, OR = 1.8 and 95% CI = 1.0-3.4). There was no appreciable association between these variant genotypes and occasional dysmenorrhea. When both the CYP2D6 and GSTM1 genotypes were considered together, the highest risk of recurrent dysmenorrhea was found among women with variant genotypes in both CYP2D6 and GSTM1 (OR = 3.1; 95% CI = 1.2-8.0). This study provides evidence of genetic susceptibility to recurrent dysmenorrhea.     

焦炉作业工人外周血淋巴细胞染色体损伤的遗传易感性研究

目的研究外源性化学物代谢酶基因多态性与焦炉作业工人外周血淋巴细胞染色体损伤的关系。方法选取149名焦炉作业工人和24名非职业多环芳烃(PAH)暴露人员作为研究对象,测定其尿中1-羟基芘浓度来反映PAH暴露的内剂量;对照组的外周血淋巴细胞微核水平的上4分位数(6‰)作为判断个体染色体损伤阳性的界值;分析CYP1A1、GSTM1、GSTT1、GSTP1、CYP2E1、NQO1、NAT2和mEH基因的多态性;使用多元logistic回归方程校正职业暴露情况、年龄、性别、吸烟和饮酒状况因素,计算不同基因型工人发生染色体损伤阳性的OR值,并探讨基因间的交互作用。结果调整了173名研究对象的职业暴露、年龄、性别、吸烟和饮酒状况后,GSTM1缺失基因型个体染色体损伤危险度显著性增加(调整OR=2．01,95％CI=1．03—3.91);与NQO1基因P187S位点野生型纯合子个体比较,变异型纯合子个体染色体损伤危险度显著性增加(调整OR=3．18,95％CI=1．18—8．62);与mEH基因H113Y位点野生型纯合子个体比较,变异型纯合子个体染色体损伤危险度显著性降低(调整OR=0．40,95％CI=0.19～0．88);未发现其他基因的遗传变异与研究对象外周血淋巴细胞染色体损伤危险度的显著关联。此外,还发现GSTM1、NQO1基因P187S位点和mEH基因H113Y位点的遗传变异对染色体损伤危险度的影响中存在基因-基因交互作用。结论本研究发现GSTM1、NQO1和mEH基因的遗传变异可显著性影响职业PAH暴露个体外周血淋巴细胞染色体损伤危险度,并存在基因一基因交互作用。     

Genetic variants of glutathione S-transferase as possible risk factors for hepatocellular carcinoma: a HuGE systematic review and meta-analysis

The authors performed a systematic review and meta-analysis to determine the effect of polymorphisms in genes encoding glutathione S-transferases (GSTs), phase II isoenzymes involved in cellular detoxification, on risk of hepatocellular carcinoma (HCC). Fifteen eligible studies were identified: 14 evaluated GSTM1; 13, GSTT1; three, GSTP1; and one each evaluated GSTM2, GSTM3, GSTA1, GSTA4, GSTO1, and GSTO2, respectively. All were case-control studies performed in populations with high (Asian, African) and medium (European) HCC incidence rates. Random-effects meta-analyses suggested a small excess risk of HCC with GSTT1 null (odds ratio (OR) = 1.19, 95% confidence interval (CI): 0.99, 1.44) and possibly GSTM1 null (OR = 1.16, 95% CI: 0.89, 1.53) genotypes. Cumulative meta-analyses demonstrated that both pooled estimators generally trended toward a small excess risk with publication of more recent studies. Results for GSTP1 A313G suggested no excess risk (OR = 0.75, 95% CI: 0.50, 1.15). A number of potentially interesting gene-gene and gene-environment interactions were reported, but these were too few and inconsistent to allow meta-analysis. The overall results suggest that there may be a small excess risk of HCC in individuals with GSTT1 null and possibly also with GSTM1 null genotypes. However, given the relatively limited total number of subjects examined and observed between-study heterogeneity, chance could not be excluded.     

细胞色素P450 2E1基因PstⅠ多态、腌制品与大肠癌关系的病例对照研究

目的：研究代谢酶细胞色素P450 2E1基因(CYP2E1)Pst Ⅰ多态性和腌制品与大肠癌易感性的关系。方法：采用人群基础的病例对照分子流行病学研究和PCR—RFLP技术,对126例大肠癌和343名健康对照Pst Ⅰ识别的CYP2E1基因型进行检测。结果：健康对照组CYP2E1基因野生型(C1／C1)为61．8％,杂合子(C1／C2)为35．8％,突变纯合子(C2／C2)为2．4％。调整年龄性别后,结肠癌病例中突变基因型频率54．9％(52．9％ C1／C2和2．0％ C2／C2)高于对照(OR 1．979,95％ CI 1．090—3．595),但直肠癌病例与对照比较,无统计学意义。分层分析发现,突变基因型、每周1或2次和隔天或每天吃腌制品单因素作用的大肠癌OR值分别1．935、2．122和2．315,而每周1或2次 突变型、隔天或每天吃 突变型联合作用后大肠癌OR值分别为2．272和3．127。分别分析结、直肠癌,腌制品对直肠癌的危险性在食用频率为每周1或2次时,差异有统计学意义,野生型和突变型的OR值分别为2．646和2．297,两者差异无统计学意义;而结肠癌危险性只有在Pst Ⅰ突变者隔天或每天吃腌制品时才剧增,OR值4．262(1．395～13．017),为野生型的2．69倍,差异有统计学意义。结论：CYP2E1 PstⅠG→C点突变是大肠癌的遗传易感性因素,与腌制品有协同作用,该作用在结肠癌尤为明显。     

Genetic Variation in GSTM1 Is Associated With Susceptibility to Noise-Induced Hearing Loss in a Chinese Population

OBJECTIVES:: To investigate whether glutathione S-transferases (GST) genetic polymorphisms (GSTT1 rs1049055, GSTM1 rs10712361, and GSTP1 rs1695) are associated with susceptibility to noise-induced hearing loss (NIHL). METHODS:: These polymorphisms were analyzed in 444 NIHL and 445 normal hearing workers. In addition, total plasma GST activity was measured in all subjects. RESULTS:: Individuals with the GSTM1 null genotype had a statistically significantly increased risk of NIHL (odds ratio [OR] = 1.64, 95% confidence interval [CI] = 1.26 to 2.13) compared with those carrying a wild-type GSTM1 genotype. This effect was more pronounced among the workers exposed to 86 to 91 dB(A) (OR = 3.35, 95% CI = 1.54 to 7.31). Glutathione S-transferase activity of the NIHL workers was also lower than that of normal hearing workers (14.5 ± 5.1 U/ml vs 15.9 ± 6.3 U/ml, P = 0.010). CONCLUSION:: Our results suggest that GSTM1 polymorphism is associated with susceptibility to NIHL.     

Evaluation of Breast Cancer Risk in a Multigenic Model Including Low Penetrance Genes Involved in Xenobiotic and Estrogen Metabolisms

Breast cancer has become the most frequent cancer among women in Westernized countries. The majority of breast cancers are due to low penetrance genes, which can act with environmental factors, particularly nutrition. Polymorphisms in gene coding for xenobiotic and estrogen metabolic pathways could increase individual cancer susceptibility and lead to the indication of individuals at higher cancer risk. A population-based, case-control study consisting of 911 breast cancer cases and 1,000 healthy control cases was performed. The association between 11 single nucleotide polymorphisms (SNP) in 7 genes and breast cancer risk was investigated in a multigenic model. The CYP1B1-432 Leu-Val and Val-Val genotypes significantly increased risk [odds ratio (OR) = 1.23, 95% confidence interval (CI) = 1.08–1.39; OR = 1.51, 95% CI = 1.17–1.94, respectively] similarly as observed with CYP1B1-453 (Asn-Ser genotype: OR = 1.17, 95% CI = 1.00–1.37; Ser-Ser genotype: OR = 1.38, 95% CI = 1.00–1.89). We showed that catechol-O-methyltransferase (COMT) could modulate the risk conferred by CYP1B1, ESR, GSTP1, and NAT2 acetylation phenotype. Additionally, a higher risk conferred by the variant for COMT was noted only for individuals presenting a high waist-to-hip ratio (COMT Val-Met, OR = 1.60, 95% CI = 1.04–2.44; COMT Met-Met, OR = 1.57, 95% CI = 0.98–2.53), suggesting a relationship with abdominal adiposity. In conclusion, COMT constitutes a crucial element in estrogen metabolism by regulating carcinogen metabolites elimination and, consequently, is a major factor in breast cancer risk.     

The Associations between Metalloestrogens,GSTP1, and SLC11A2 Polymorphism and the Risk of Endometrial Cancer

Background: The incidence of endometrial cancer (EC) is still rising. Numerous risk factors including patient characteristics and molecular instability have been identified for EC. The presence of specific molecular markers allows specific diagnostic and prognostic approaches. Several single nucleotide polymorphisms (SNPs) have been identified to influence endometrial cancer risk. Metalloestrogens are metal ions which can mimic estrogen activity; however, their role in uterine pathologies remains unknown. This study aimed to investigate total blood trace elements levels and evaluate the distribution of selected genotypes in GSTP1 and SLC11A2 genes. Methods: This retrospective case-control analysis was carried out in peripheral blood samples of 110 women with endometrial cancer (EC; n = 21), uterine fibroma (n = 25), endometrial polyp (n = 48), and normal endometrium (n = 16). Analysis included measurement of metals and phosphor in serum, and of genetic polymorphisms in GST (rs1695) and SLC11A2 (rs224589) in DNA from white blood cells. Serum trace elements were measured using ICP-OES spectrometry. SNPs were identified using Taq Man real-time PCR genotyping assays. Results: The study confirmed higher age (OR 2.19, 95% CI 1.69–2.24), post-menopausal status (OR 1.89, 95% CI 1.36–1.94), and diabetes type 2 (OR 1.54; 95% CI 0.97–1.72) as independent risk factors for EC. We also found a high level of Cd (OR 1.49; 95% CI 1.31–1.63) and a low level of Co (OR 0.76; 95% CI 0.53–0.59) to be independent risk factors of EC. None of the tested polymorphisms of GSTP1 and SLC11A2 were associated with EC risk. However, high Cd (OR 1.21, 95% CI 1.15–1.29) and Ni (OR 1.07, 95% CI 1.05–1.18) serum levels were significantly associated with a SLC1A2 TG genotype, and high Cd levels with GSTP1 (OR 1.05, 95% CI 1.01–1.13).     

Genetic polymorphism of metabolic enzymes modifies the risk of chronic solvent-induced encephalopathy

In the present study, we investigate whether genetic polymorphism in enzymes involved in the metabolism of organic solvents influences susceptibility to chronic solvent encephalopathy (CSE), which is one of the major effects of long-term exposure to organic solvents. Polymorphisms in the genes encoding CYP1A1, CYP2E1, EPHX1, GSTM1, GSTT1 and GSTP1 enzymes were determined in a group of male CSE patients (N=97) and controls (N=214). The selection of the patients was based on a standard diagnostic protocol, including interviews, neuropsychological tests and questionnaires directed to somatic, cognitive and mood symptoms and exposure, in combination with well-defined decision rules. As controls, healthy workers of similar socio-economic background, without memory problems and with no known exposure to organic solvents, were included in the study. Comparing patients and controls, higher frequencies of the variant *5B allele of the CYP2E1 gene (OR: 5.8; 95% CI: 1.8-18.8) and of the variant GSTP1*C allele (OR: 0.40; 95% CI: 0.17-0.94) were found. Homozygous carriers of the exon 4 EPHX1 Arg139 variant allele had a lower risk (OR: 0.25; 95% CI: 0.06-1.13). The present study indicates that genetic polymorphism of CYP2E1, EPHX1 and GSTP1 modify the risk of developing CSE.     

GSTT1 genotype modifies the association between cruciferous vegetable intake and the risk of myocardial infarction

BACKGROUND: Cruciferous vegetables are a major dietary source of isothiocyanates that may protect against coronary heart disease. Isothiocyanates induce glutathione S-transferases (GSTs), polymorphic genes that code for enzymes that conjugate isothiocyanates, as well as mutagens and reactive oxygen species, to make them more readily excretable. OBJECTIVE: The objective of the study was to determine whether GST genotypes modify the association between cruciferous vegetable intake and the risk of myocardial infarction (MI). DESIGN: Cases (n = 2042) with a first acute nonfatal MI and population-based controls (n = 2042) living in Costa Rica, who were matched for age, sex, and area of residence, were genotyped for a deletion polymorphism in GSTM1 and GSTT1 and an Ile105Val substitution in GSTP1. Cruciferous vegetable intake and smoking status were determined by questionnaire. Odds ratios (ORs) and 95% CIs for MI were estimated by unconditional logistic regression. RESULTS: Compared with the lowest tertile of cruciferous vegetable intake, the highest tertile was associated with a lower risk of MI among persons with the functional GSTT1*1 allele (OR: 0.70; 95% CI: 0.58, 0.84) but not among those with the GSTT1*0*0 genotype (OR: 1.23; 95% CI: 0.83, 1.82) (P = 0.006 for interaction). This protective effect among those with the GSTT1*1 allele was greater for current smokers (OR: 0.54; 95% CI: 0.36, 0.79) than for nonsmokers. GSTP1 and GSTM1 did not modify the association between cruciferous vegetable intake and MI. CONCLUSIONS: Consumption of cruciferous vegetables was associated with a lower risk of MI among those with a functional GSTT1*1 allele, which suggests that compounds that are detoxified by this enzyme contribute to the risk of MI.     

谷胱甘肽转硫酶M1和T1基因型与高原反应的危险性

目的探讨谷胱甘肽转硫酶M1、T1基因型(GSTM1、GSTT1)与高原反应危险性的关系。方法从同一生活和工作环境中选取123名男性武警战士作为调查对象，根据是否发生急性高原反应，将其分成病例组和对照组，其中病例组43人、对照组80人。基因组DNA来自研究对象提供的外周血有核细胞，采用多重聚合酶链反应(17CR)方法对这些武警战士的谷胱甘肽转硫酶M1和T1基因进行分型。结果病例组GSTT1非缺失型基因频率为69．8％，明显高于正常对照组(42．5％)，差异有统计学意义(P=0．004，OR=3．12，95％CI为1．42—6．86)。两组GSTM1缺失型基因频率分别为72．1％和52．5％，差异有统计学意义(P=0．03，OR=2．34，95％CI为1．05—5．02)。GSTT1阴性／GSTM1阴性基因型者发生高原反应的危险性比携带GSTT1阴性／GSTM1阳性者高5倍(OR=5．04；95％CI为1．00-25．3)。结论谷胱甘肽转硫酶M1、T1基因多态性与高原反应危险性有关。     

吉林市汉族妇女GSTM1基因和CYP1A1基因Exon7位点多态性与 子宫内膜异位症易感性的研究

目的:探讨在吉林地区汉族妇女中细胞色素P450(CYP1A1)基因Exon7位点多态性即Ile-Val位点的多态性及GSTM1基因多态性和子宫内膜异位症易感性的相关关系。方法:以病例对照的研究方法,采用PCR技术检测216例子宫内膜异位症和216例对照人群的CYP1A1基因Ile-Val位点及GSTM1基因多态性的表达。结果:吉林地区汉族人群中GSTM1空白基因型分布频率0.463,内异症人群中空白基因型分布频率0.667,两组差异有统计学意义(P<0.05),空白基因型患内异症的危险是功能基因型的1.896倍;Ile-Val三种多态基因型在内异症组和对照组分布差异有统计学意义(P<0.05),Ile/Val、Val/Val基因型患内异症的危险分别是Ile/Ile基因型的1.901倍和3.056倍;CYP1A1 Ile/Val联合GSTM1空白基因型个体的OR值为3.409(95%C I 1.897~6.125,P<0.01),而CYP1A1Val/Val联合GSTM1空白基因型个体的OR值增高至7.143(95%C I 2.584~19.742,P<0.01)。结论:CYP1A1 Exon7的Ile/Val、Val/Val基因型及GSTM1空白基因型与内异症的易感性有关,二者联合效应具有协同作用,可望作为内异症易感人群筛选的重要指标。     

氯乙烯接触工人DNA损伤与代谢酶基因多态关系研究

目的探讨氯乙烯(VCM)所致DNA损伤与VCM代谢酶多态间的关系。方法彗星实验测DNA损伤,并按DNA损伤情况将工人分为DNA损伤组和对照组,采用病例-对照设计,PCRRFLP测CYP2E1c1c2、mEH4His139Arg基因多态;PCR法测GSTT1、GSTM1缺失情况。结果CYP2E1c1c2和c2c2基因型与DNA损伤显著相关(P<0.01)。累积接触剂量高和低的个体同时具CYP2E1c1c2c2c2基因型,其DNA损伤发生率均显著高于对照,差异具统计学意义(OR4.92,95%CI1.35～13.85和OR2.57,95%CI1.01～6.59)。结论VCM累积接触剂量和代谢酶CYP2E1基因型与VCM诱导的DNA损伤有关。     

焦炉工代谢酶和DNA修复酶基因多态性与DNA损伤的关系

目的研究外源性化学物代谢酶和DNA损伤修复酶基因多态性与焦炉作业工人外周血淋巴细胞DNA损伤易感性的关系。方法选取144名焦炉作业工人(暴露组)和50名医务人员(对照组)作为研究对象,测定其尿中1-羟基芘浓度来反映多环芳烃暴露内剂量,用碱性彗星试验评价个体外周血淋巴细胞DNA损伤,分析细胞色素P4501A1、细胞色素P4502E1、谷胱甘肽S-转移酶P1(GSTP1)、还原型辅酶2-醌氧化还原酶、环氧化物水化酶和XRCC1基因的多态性,以及不同基因型与DNA损伤的关系。结果暴露组尿中1-羟基芘浓度为11．8μmol／mol肌酐、彗星尾矩为3．2,均高于对照组(尿中1-羟基芘浓度为0．7μmol／mol肌酐、彗星尾矩为1．1);暴露组中XRCC1 Arg280His位点变异基因型个体的彗星尾矩(5．6)显著高于野生型个体(2．8)。以1．74为界值,将全部研究对象的彗星尾矩转化为分类变量后的回归分析结果表明,XRCC1 Arg280His位点变异基因型个体发生DNA损伤的危险度显著高于野生基因型个体;GSTP1 Ile104Val位点变异基因型个体发生DNA损伤的危险度高于野生基因型个体,但差异无统计学意义。结论XRCC1 280His和GSTP1 104Val等位基因可增加职业性多环芳烃暴露导致的外周血淋巴细胞DNA损伤水平。     

代谢酶基因多态性与结直肠癌的易感性

目的研究代谢酶细胞色素P450（cytochrome P450s,CYP）1A1、谷胱甘肽转移酶（glutathione—S-transferase,GST）M1和T1、尿苷二磷酸葡萄糖醛酸转移酶（UDPglucumnosyltransferase,UGT）1A7基因多态性与结直肠癌的易感性及其交互作用。方法2002年5月在浙江省嘉善县开展的现场病例对照研究及单纯病例研究,获得140例结直肠癌患者和343名健康对照,用PCR-限制性片段长度多态性等方法检测CYP1A1、GSTM1、GSTT1和UGT1A7的基因多态,并应用非条件logistic回归方法进行数据分析。结果CYPIA1 MspI多态（非编码区T6235C）C／C基因型、T／C和C／C基因型者相对于T／T基因型者的OR值分别为0．493（95％CI：0．254—0．956）和0．638（95％CI：0．427—0．952）,具有统计学意义;GSTM1、GSTT1非缺陷型与缺陷型的分布频率对照组和病例组比较差异无统计学意义;对照组和病例组UGT1A7变异／变异型基因与野生纯合型基因比较差异有统计学意义（OR=2．501,95％CI：1．456—4．296）。单纯病例研究分析,CYP1A1与GSTT1、GSTM1与GSTT1对结直肠癌的发生存在交互作用,COR值分别为2．617（95％CI：1．015—6．752）和3．935（95％CI：1．323—11．706）;而CYPlAl与GSTM1、CYP1A1与UGT1A7之间无交互作用。结论CYP1A1 MspI变异型可降低机体对结直肠癌的易感性,而UGT1A7的变异／变异基因型可增加结直肠癌的罹患风险,CYP1A1与GSTT1、GSTM1与GSTT1对结直肠癌的发生存在交互作用。     

Adherence to Mediterranean-Style Dietary Pattern and Risk of Esophageal Squamous Cell Carcinoma: A Case-Control Study in Iran

Objective: The benefit of adherence to a Mediterranean-style dietary pattern in relation to the risk of esophageal squamous cell carcinoma (ESCC) has not been investigated among non-Mediterranean high-risk populations. The objective of the present study was to examine the association of compliance with the Mediterranean dietary pattern as measured by Mediterranean-Style Dietary Pattern Score (MSDPS) and the risk of ESCC in Iranian population.

Methods: This case-control study was conducted on 47 ESCC cases and 96 hospital controls aged 40–75 years. Participants were interviewed using validated questionnaires, and dietary patterns were characterized using the MSDPS.

Results: Generally, the mean MSDPS in this population was low (30.84 ± 8.58). MSDPS showed content validity through having expected positive associations with several lifestyle characteristics and dietary intakes. Being in the highest quartile category of MSDPS, compared to the lowest, was independently associated with 37% reduction in risk of ESCC. Two-unit and 3-unit increases in the MSDPS resulted in 41% and 47% reduction in risk of ESCC, respectively. Higher intakes of olive oil (odds ratio [OR] = 0.15, 95% CI: 0.01–0.49), fish and other seafood (OR = 0.48, 95% CI: 0.23–0.98), whole grain (OR = 0.57, 95% CI: 0.28–0.76), and fruits (OR = 0.77, 95% CI: 0.38–0.86) were significantly associated with reduced ESCC risk. In contrast, higher sweet (OR = 1.86, 95% CI: 1.04–2.12) and meat intakes (OR = 1.61, 95% CI: 1.25–2.49) were associated with higher ESCC risk.

Conclusion: Consuming a diet in concordance with the principles of the Mediterranean dietary pattern may protect against ESCC. Preventive strategies to reduce ESCC risk in high-risk countries should focus on overall dietary pattern and dietary habits to be effective.     

Association of Activity Altering Genotypes - Tyr113His and His139Arg in Microsomal Epoxide Hydrolase Enzyme with Esophageal Squamous Cell Carcinoma

The study aimed to explore the relationship of microsomal epoxide hydrolase (mEH) exon 3 (Tyr113His) and exon 4 (His139Arg) polymorphisms and predicted mEH activity with esophageal squamous cell carcinoma (ESCC) risk. 482 histologically confirmed cases and equal number of matched controls were analyzed by polymerase chain reaction-restriction length polymorphism (PCR-RFLP). Conditional logistic regression models were used to examine the association of polymorphisms with ESCC. We noted exon 3 slow genotype (OR?=?6.57; CI 3.43–12.57) as well as predicted low mEH activity (OR?=?3.99; CI 2.32–6.85) was associated with the ESCC risk. Elevated ESCC risk estimates were seen in smokers independent of genotypes but the association was stronger among smokers with exon 3 variant (OR?=?6.67; 3.29–13.53) and low activity (OR?=?7.52; CI 3.46–16.37) genotypes. Positive family history of cancer synergistically increased ESCC risk in the individuals who harbored exon 3 (OR?=?13.59; CI 5.63–32.81) or altered mEH activity genotypes (OR?=?13.35; CI 5.10–34.94). Significant interaction was seen between mEH exon 3 and exon 4 genotypes (P?=?0.006) and between predicted mEH activity and positive family history of cancer (P?=?0.018). These findings suggest association of ESCC risk with mEH polymorphisms which get modified by tobacco smoking and positive family history of cancer.