四川人群中CYP1A1基因Ile-Val和Msp1位点多态性与肺癌易感性的研究

目的　探讨细胞色素P45 0 (CYP1A1)基因异亮氨酸 (Ile) 缬氨酸 (Val)位点和Msp1位点多态性和肺癌易感性的相关关系。方法　以病例对照的研究方法 ,采用PCR RFLP和ASA PCR技术检测 82例原发性肺癌和 91例对照的CYP1A1基因Ile Val位点和Msp1位点多态性。 结果　Ile Val三种多态基因型在肺癌组和对照组分布差异有显著性 (P <0 .0 5 ) ,Ile/Val、Val/Val基因型在肺癌组的分布频率明显高于对照组 ;logistic回归分析结果显示Ile/Val、Val/Val基因型患肺癌的危险分别是Ile/Ile基因型的 1.969倍和3 .15 0倍 ;当按吸烟分层后 (将Ile/Val、Val/Val基因型合并分析 ) ,吸烟组中Ile/Val、Val/Val合并基因型患肺癌的危险是Ile/Ile基因型的 3 .0 5 9倍 ,而在不吸烟组其OR为 1.687;Msp1位点多态性在肺癌组和对照组差异无统计学意义。结论　CYP1A1第 7外显子的Ile/Val、Val/Val基因型与肺癌的易感性有关 ,可望作为肺癌易感人群筛选的重要指标 ;尚不能认为Msp1多态性与肺癌的易感性有关     

细胞色素P450 2E1基因多态性与肺癌易感性的研究

目的 :研究与致癌物有关的代谢酶细胞色素P45 0 2E1(CYP 2E1)基因多态性和饮酒与肺癌易感性的关系。方法 :采用聚合酶链反应 (PolymeraseChainReaction ,PCR)和限制性片段长度多态性 (RestrictionFregmentLengthPolymorphisms ,RFLP)方法 ,分析 91例肺癌患者和 138例对照的Rsal认别的CYP 2E1基因型。 结果 :本次研究结果为CYP 2E1基因型频率在肺癌组和对照组的分布差异无显著性意义 (χ2 =1 35 5 ,P >0 0 5 ) ;CYP 2E1C1/C1基因型或饮酒单因素作用的比值比 (OddsRatil,OR)分别为 1 389和 3 33,而两者联合作用的OR为 5 4 1。结论 :CYP 2E1基因多态性与肺癌无明显相关性 ,但与饮酒有联合作用。     

细胞色素P450 2E1和1A1多态性与肺癌关系的病例对照研究

目的 :探讨细胞色素P45 0 2E1和P45 0 1A1的多态性与肺癌的关系。方法 :采用聚合酶链式反应和限制性片段长度多态性技术检测新发肺癌患者91例及非肺部疾患同性别的患者 91例的细胞色素CYP 2E1和CYP 1A1的基因多态性 ,并分析比较。结果 :在 2组间平衡吸烟的因素后 ,CYP 2E1和CYP 1A1基因多态性分别单独分析时 ,与肺癌关系较弱 ,其OR值分别为 1 46和 1 5 1,与对照组相比差异无统计学意义 ,P >0 0 5 ;而两者联合分析时 ,CYP2E1C1C1型和CYP 1A1突变型的OR值为 3 0 0 ,95 %CI为 1 0 3～ 8 78,差异有统计学意义 ,χ2 =4 0 2 ,P <0 0 5。结论 :CYP 2E1和CYP 1A1单一基因的多态性不能增加患肺癌的危险 ,而两者联合作用时则可增强患肺癌的风险。     

CYP2C9、GSTM1基因多态性与肺癌易感性的关系

目的探讨细胞色素P4502C9(CYP2C9)基因、谷胱甘肽硫转移酶M1(GST M1)基因多态性与肺癌易感性的关系。方法用PCR-RFLP法分析56例肺癌(简称肺癌组)和42例健康对照组NsiⅠ识别的CYP2C9基因型;用PCR法分析其GST M1基因型。结果突变型CYP2C9*3型基因发生频率在肺癌组中为8.93%,高于对照组的4.76%,其差异无显著性(P>0.05)。肺癌组GST M1基因缺失型〔GST M1(-)〕发生率为71.43%,高于对照组的45.24%,其差异有显著性(P<0.01);GST M1(-)型与肺癌呈高度联系强度,OR=3.09(95%CI=1.32~6.94);GST(-)基因型在吸烟的肺癌组(81.08%)与对照组(52.18%)之间的频率差异有显著性(P<0.05)。结论突变型CYP2C9*3型基因与肺癌无显著性联系;GST M1(-)基因型是肺癌发生的遗传易患性因素;吸烟可显著提高GST(-)基因型个体患肺癌的危险性。     

CYP1A1、GSTM1基因多态性与肺癌易感性的研究

目的:探讨CYP1A1、GSTM1基因多态性与肺癌易感性之间的相关性。方法:利用RFLP-PCR(限制性片段长度多态性-聚合酶链反应)方法检测65例原发性肺癌和60例非肿瘤患者CYP1A1、GSTM1基因,再用NcoI及HinfI两种内切酶识别CYP1A1等位基因亚型。结果:1)肺癌组与对照组CYP1A1等位基因型Ile/Ile、Ile/Val、Val/Val的频率总体分布无显著性差异;但肺癌组CYP1A1(Val/Val)基因型频率(18.5%)明显高于对照组(8.3%),两组差异有显著性(P<0.05)。2)肺癌组GSTM1(-)基因型的频率(63.1%)明显高于对照组(45.0%),P<0.05。3)两种等位基因联合分析发现,与携带CYP1A1(Ile/Ile)/GSTM1(+)基因型的个体相比:CYP1A1(Ile/Ile)/GSTM1(-)以及CYP1A1(Ile/Val+Val/Val)/GSTM1(+)基因型个体患肺癌的风险度较高,OR分别为3.82(95.0%CI,1.27～11.45)和3.5(95.0%CI,1.18～10.41);而CYP1A1(Val/Val)/GSTM1(-)基因型个体患肺癌的风险度最高,OR为10.5(95.0%CI,1.70～64.73)。4)进一步分层分析发现,CYP1A1(Ile/Val+Val/Val)等位基因型主要增加鳞癌的危险性;而GSTM1基因型组织类型无明显的相关性。5)在分析吸烟对肺癌易感性的影响时发现,CYP1A1(Ile/Val+Val/Val)及GSTM1(-)等位基因型与吸烟有协同作用,并与至发病时的累积吸烟量有关。结论:CYP1A1(Val/Val     

广州地区182例汉族人细胞色素P450 1A1和2E1基因多态性与肺癌关系的病例对照研究

背景与目的 肺癌的易感性研究多集中在单个基因的多态性方面，本研究观察了广州地区汉族人群细胞色素P4502E1（CYP2E1）和1A1（CYP1A1）的基因多态性与肺癌的关系，分析其联合作用。方法 采用聚合酶链反应和限制性片段长度多态性技术检测91例初发肺癌患者及91例非肺部疾患同性别患者的CYP2E1和CYP1A1的基因多态性，并分析比较。结果 在两组间平衡吸烟的因素后，CYP2E1和CYP1A1基因多态性分别单独分析时，与肺癌关系较弱，其OR值分别为5．48和1．51，与对照组之间的差异无显著性（P〉0．05）。两者联合分析时，CYP2E1野生型和CYP1A1突变型联合者的OR值为3．00，95％CI为1．03～8．78，其差异有显著性（P〈0．05）。结论 CYP2E1和CYP1A1单一基因的多态性不能增加患肺癌的危险，而两者联合作用时则可增强患肺癌的风险。     

CYP1A1多态性与肺癌遗传易感性的关系

目的探讨代谢酶基因CYP1A1基因多态性与中国汉族人群肺癌遗传易感性之间的相关性。方法应用AS-PCR技术检测150例中国四川汉族肺癌和152例中国四川汉族健康人的CYP1A1基因Exon7多态性分布频率,并分析了Exon7多态性与中国四川汉族人群肺癌遗传易感性之间的相关性。结果CYP1A1Exon73种多态基因型分布频率在两组间比较差异无统计学意义,χ2=0.634,P=0.728。携带突变Val基因型的个体较携带Ile/Ile基因型的个体患肺癌的危险性增加,OR=1.139,95%CI为0.635~2.042,P=0.662。携带突变Val基因型的个体较携带Ile/Ile基因型的个体患肺鳞癌的风险显著增加,OR=3.510,95%CI=1.326~9.293,P=0.011。结论Val突变等位基因可能是中国四川汉族人群的肺癌易感基因。CYP1A1基因Exon7多态性在肺鳞癌发生中起重要作用。     

CYP1A1 GSTM1基因多态性和吸烟与肺癌易感性关系的病例对照研究

目的:探讨天津市居民致癌物代谢酶CYP1A1和GSTM1基因多态性对肺癌易感性的影响。方法:利用限制性片断长度多态性-聚合酶链反应(RFLP-PCR)方法检测原发性肺癌患者和健康对照者细胞色素P450酶基因CYP1A1Msp位点和谷胱甘肽硫转移酶基因GSTM1的多态性情况。结果:肺癌组与对照组之间CYP1A1和GSTM1基因型分布差异均存在统计学显著意义(P<0.05)。携带CYP1A1变异基因型或GSTM1阴性基因型的个体患肺癌的危险性增高,比值比(OR)分别达到2.44(1.04～5.81)和1.84(1.03～3.29)。多因素分析结果显示具有CYP1A1变异基因型、GSTM1阴性基因型的吸烟个体患肺癌的风险较大。结论:CYP1A1Msp位点变异基因型和GSTM1阴性基因型可能是肺癌的易感因素,吸烟与肺癌易感基因之间具有协同作用。     

广州地区汉族人群肺癌易感性标记物CYP1A1、CYP2E1和GSTM1与肺癌关系的病例对照研究

[目的]探讨广州地区汉族人群谷胱苷肽硫转移酶（GSTM1）、细胞色素P4501A1（CYP1A1）和细胞色素P4502E1（CYP2E1）基因多态性与肺癌易感性的关系。[方法]选取中山大学附属第一医院、广州市肿瘤医院、广州市红十字会医院等医院的广州籍新发肺癌病人91例及同期上述各医院的同性别非肺部疾患病人91例作对照，采用聚合酶链式反应（PCR）和限制性片段长度多态性（RFLP）技术检测CYP1A1、CYP2E1和GSTM1的基因多态性。[结果]与野生型的CYP1A1相比，突变型肺癌OR为1．51（0．76～3．011。CYP2E1C2C2基因型与C1C1基因型比较，其OR为5．48（1．21～25．23）．GSTM1基因缺失型的OR值为1．26（0．69～2.30）．而三者联合作用时．则可增加患肺癌的危险，其OR值为3．97（0．94-16．791，但无统计学意义（P〉0．05）。[结论]CYP1A1、CYP2E1和GSTM1的某些基因型增加了患肺癌的危险性，但尚未达到统计学的显著性水平，说明它们均不是肺癌个体易感性的主效基因．而是次效基因。     

GSTM1和CYP2E1基因多态性与肺癌遗传易感性关系的研究

背景与目的肺癌是中国人群恶性肿瘤死因的首位，其发病可能与肺癌人群中某些肺癌相关基因的遗传多态性有关。本研究旨在探讨细胞色素P4502E1(CYP2E1)基因RsaⅠ／PstⅠ多态性和谷胱甘肽转移酶M1(GSTM1)基因多态性与肺癌易感性之间是否存在相关性。方法应用PCR-RFLP和PCR法检测99例人非小细胞肺癌患者和66例同期住院的肺良性疾病患者CYP2E1基因的RsaⅠ／PstⅠ多态性和GSTM1基因多态性，并分析其与肺癌遗传易感性的相关性。结果(1)CYP2E1基因RsaⅠ／PstⅠ多态性的三种基因型在肺癌组和对照组的频率差异没有统计学意义(χ^2=1．374，P=0．241)。(2)肺癌组GSTM1(-)基因型频率显著高于对照组(分别为57．6％和40．9％)(χ^2=4．401，P=0．036)。(3)携带GSTM1(-)基因型的个体患肺癌的危险性显著高于GSTM1( )基因型的个体(OR=1．96，95％CI=1．042～3．689，P=0．037)。(4)与携带c1／c2或c2／c2基因型的不吸烟个体比较，携带c1／c1基因型的吸烟者患肺癌的风险显著增加(OR=3．525，95％CI=1．168～10．638，P=0．025)。(5)联合分析CYP2E1基因RsaⅠ／PstⅠ多态性和GSTM1基因多态性，携带有c1／c1和GSTM1(-)基因型的个体患肺癌的风险显著高于携带GSTM1( )和c1／c2或c2／c2基因型的个体(OR=3．449，95％CO=1．001～11．886，P=0．050)。按照吸烟因素分层，携带有GSTM1(-)和c1／c1基因型的不吸烟个体患肺癌的风险显著高于携带GSTM1( )和c1／c2或c2／c2基因型的不吸烟个体(OR=11．553，95％CI=1．068-124．944，P=0．044)，携带有GSTM1(-)和c1／c2或c2／c2基因型的不吸烟个体患肺癌的风险同样显著高于携带GSTM1( )和c1／c2或c2／c2基因型的不吸烟个体(OR=13．374，95％CI=1．258～142．166，P=0．032)。结论(1)GSTM1(-)基因型增加人群患肺癌的风险；(2)CYP2E1的c1／c1基因型和GSTM1(-)基因型的联合可增加吸烟和不吸烟人群患肺癌的风险。     

细胞色素CYP2E1和GST M1与肺癌易感性的病例对照研究

目的探讨谷胱甘肽转硫酶(GST)和细胞色素CYP2E1多态性与肺癌易感性的关系.方法选取广州市广东籍新发肺癌病人91例及同期非肺部疾患及相同性别的病人91例作匹配,调查他们的吸烟、饮酒等因素的暴露情况.用聚合酶链式反应(PCR)和限制性片段长度多态性(RFLP)技术检测CYP2E1和GST的基因多态性.结果CYP2E1 C1C1基因型与C1C2基因型比较,其OR为1.82(95%CI=0.95～3.40),GSTM1基因缺失型的OR值为1.26(0.69～2.30),而两者联合分析时,则可增加患肺癌的危险,其OR值为2.13(0.82～5.56),但无统计学意义(P＞0.05).吸烟与肺癌关系密切,其OR值为2.82(1.56～5.12),当吸烟与这两种基因型协同作用时,可明显提高患肺癌的危险性,携带CYP2E1 C1C1基因型的吸烟者的OR值为5.42(2.05～14.32),GSTM1基因缺失型的吸烟者的OR值为4.38(1.81～10.61).多因素logistic回归分析结果表明:文化程度(OR为0.63,0.45～0.86)、吸烟量(OR为1.56,1.14～2.14)、元抽油烟机(OR为3.77,1.48～9.56)、食用动物油(OR为1.67,1.25～2.24)、胡萝卜(OR为0.47,0.22～0.98)、饮酒(OR为6.58,1.53～28.3)、直系亲属肺癌史(OR为3.75,1.64～8.58)等因素与肺癌有关,而上述两种基因均未进入模型.结论CYP2E1和GSTM1在单因素分析中未显示出与肺癌风险的联系.这两种基因分别与吸烟协同作用时明显提高肺癌的危险性.然而在多因素分析中均未进入logistic模型,说明它们均不是肺癌个体易感性的主效基因,而是次效基因.     

Genetic Polymorphisms of Xenobiotic Metabolizing Genes (GSTM1, GSTT1, GSTP1), Gene-Gene Interaction with Association to Lung Cancer Risk in North India; A Case Control Study

Aim: In this case control study involving, 220 human subjects; polymorphisms in xenobiotic metabolizing genes (GST-M1, -T1 and -P1) and their association to lung cancer risk is being analysed among smokers and non-smokers. GSTM1 or GSTT1 gene polymorphism and amino acid changes in GSTP1 have been correlated and may be associated to lung cancer risk. Other factor includes exposure to environmental pollutants and life style choices. We have explored gene-gene and gene-environment interaction in the aetiology of lung cancer risk among north Indian population. Patients and Methods: For the study we have collected 120 lung cancer patient blood samples from Kamala Nehru Memorial Cancer Hospital, Allahabad, Uttar Pradesh and 100 matched controls. DNA was isolated and GST-M1 and - T1 genotyping were assessed by multiplex PCR whereas the GSTP1 polymorphism was analysed using restriction fragment length polymorphism. The risk of lung carcinogenesis was assessed using logistic regression analysis calculating the odd ratio (OR) with 95% confidence interval (CI). Results: The risk of lung carcinogenesis was three fold higher for null GSTT1 (OR=3.045, 95%CI=1.750-5.301, p-value <0.001) genotype; whereas other two types; GSTM1 (OR= 1.342, 95% CI=0.788-2.284, p-value=0.270) and GSTP1 (OR=0.806, 95% CI=0.526-1.236, p-value=0.323) showed no association to lung cancer susceptibility respectively. Smokers diagnosed with lung cancer had more null genotypes for GSTT1 (OR=4.773, 95%CI=1.939-11.751, p<0.001). The ‘at risk’ genotype combination GSTM1 (null) /GSTT1 (null) (OR=1.76, 95%CI; 0.920-3.370, p-value=0.03) showed increased susceptibility to lung cancer risk. The genotype combination of GSTT1 (null)/GSTP1 (Ile/Ile) (p=0.009) was associated with increased lung cancer risk. Conclusion: The results of this study suggest that; GSTT1 null genotype were more susceptible for lung cancer risk and smoking increases the susceptibility for lung cancer several folds among the North Indian population. Gene-gene interaction for null genotypes of GSTM1 and GSTT1 were correlated with higher risk of having lung cancer.     

CYP1A1 Ile462Val and MPO G-463A interact to increase risk of adenocarcinoma but not squamous cell carcinoma of the lung

Common polymorphisms in genes encoding phase I and phase II enzymes are considered to modify lung cancer risk due to changes in enzyme activity. Candidates include genetic variants of glutathione S-transferases (GSTM1, GSTT1 and GSTP1) and myeloperoxidase (MPO). We performed a large case-control study of these candidate genes in 1103 patients with non-small cell lung cancer (NSCLC) and 627 controls without NSCLC. Associations between deletion genotypes of GSTM1 and GSTT1 and between single nucleotide polymorphisms (SNPs) of GSTP1 Ile105Val and MPO G-463A were first tested by adjusted logistic regression. Then we analysed gene-gene interactions, also incorporating our published data on the Ile462Val SNP in the phase I enzyme, cytochrome P450 CYP1A1. The homozygous GSTP1 105Val genotype was significantly under-represented in NSCLC compared with controls (OR = 0.73; 95%CI 0.53-1.00; P = 0.050), especially in females (OR = 0.57; 95%CI 0.34-0.98; P = 0.04). The GSTT1-null genotype was significantly over-represented in adenocarcinomas (OR = 1.41; 95%CI 1.06-1.90; P = 0.02) but not in squamous cell carcinomas (OR = 1.03; 95%CI 0.76-1.41; P = 0.84). There was weak risk reduction associated with GSTM1 null in heavy smokers (OR = 0.71; 95%CI 0.54-0.94; P = 0.02), but neither GSTM1 nor MPO genotypes affected the overall risk of NSCLC. The MPO and CYP1A1 risk genotypes interacted to increase the overall risk of NSCLC (OR = 2.88; 95%CI 1.70-5.00; P < 0.001). The data are consistent with the concept that multiple genes of modest effect interact to confer genomic-based susceptibility to lung cancer.     

58. Susceptibility to lung cancer is associated with genetic polymorphisms of CYP1A1、GSTM1

Objective: To investigate the association of lung cancer susceptibility with genetic Polymorphism of CYP1A1 and GSTM1. Methods: The study was conducted on 65 lung cancer cases and 60 no-cancer controls. The genetic polymorphism both CYP1A1 and GSTM1 were performed in cancer tissues of all patients and peripheral blood leukocytes of no-cancer controls. First by RFLP-PCR, then after incubating with restriction enzyme Ncol and Hinfl. Results: ①There were no significant differences in the frequency distribution of CYP1A1 polymorphisms between lung cancer patients and controls, but the frequency of CYP1A1(Val/Val) was significant higher than that controls (P<0.05). ②If OR for CYP1A1 (Ile/Ile) genotype was 1.0, the OR of CYP1A1 (Ile/VaL)、CYP1A1 (Val/Val) was 1.68 (95%CI, 0.79～3.59) and 3.2 (95%CI, 1.06～10.26), respectively. ③The significant difference were observed that GSTM1(-) became markedly expressed (63.1%, 41/65) in elung cancer patients than in the corresponding controls (45%, 27/60) (P<0.05), OR was 2.09 (95%CI, 1.02～4.26); ④When analysis combined CYP1A1 and GSTM1 genotype, we found that individual who take along CYP1A1 (Ile/Ile)/GSTM1 (-) or CYP1A1 (Ile/Val+Val/Val)/GSTM1 (+) genotype had higher odds ratio than CYP1A1 (Ile/Ile)/GSTM1 (+) genotype, the OR was 3.82 (95%CI, 1.27～11.45) and 3.5 (95%CI 1.18～10.41), respectively, but the CYP1A1 (Val/Val) / GSTM1 (-) genotype was the hightest odds ratio, the OR was 10.5 (95%CI, 1.70～64.73). ⑤We observed that the individual who carry CYP1A1(Val/Val) genotype can increased risk of squamous cell carcinoma of lung (P<0.05), OR was 2.75 (95%CI, 1.24～6.17), there was no significant associated of pathologic with GSTM1 genotype. ⑥Stratified analysis suggested an interaction between cigarettes smoking and CYP1A1 (Ile/Val+Val/Val)、GSTM1 (-) genotype. Conclusion: ①The individuals who carried genotype of CYP1A1 (Val/Val) and GSTM1 (-) were susceptible to lung cancer. ②the individuals who carried CYP1A1 (Ile/Ile) /GSTM1 (-) or CYP1A1 (Ile/Val+Val/Val) /GSTM1 (+) genotype with higher risk of developing lung cancer than that CYP1A1 (Ile/Ile)/GSTM1 (+) genotype. ③There were interaction between smoking and CYP1A1 (Ile/Val+Val/Val)、GSTM1 (-)     

Updated Meta-analysis of the Association Between CYP2E1 RsaI/PstI Polymorphisms and Lung Cancer Risk in Chinese Population

Background: A number of studies have reported relationships of CYP2E1 RsaI/PstI polymorphisms with susceptibility to lung cancer in Chinese population. However, the epidemiologic results have been conflictive rather than conclusive. The purpose of this study was to address the associations of CYP2E1 RsaI/PstI polymorphisms with lung cancer risk in Chinese population comprehensively. Materials and Methods: Systematic searches were conducted in the PubMed, Science Direct, Elsevier, CNKI and Chinese Biomedical Literature Databases. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of association. Results: Overall, we observed a decreased lung cancer risk among subjects carrying CYP2E1 RsaI/PstI c1/c2 and c1/c2+c2/c2 genotypes (OR=0.76, 95%CI: 0.64-0.90 and OR=0.78, 95%CI: 0.66-0.93, respectively), as compared with subjects carrying the c1/c1 genotype. In subgroup analysis, we observed a decreased lung cancer risk among c1/c2 carriers in hospital-based studies (OR=0.81, 95%CI: 0.68-0.98) and among carriers with c1/c2 and c1/c2+c2/c2 genotypes in population-based studies(OR=0.57, 95%CI: 0.42-0.79 and OR=0.58, 95%CI: 0.43-0.79, respectively), as compared with subjects carrying the c1/c1 genotype. Limiting the analysis to studies with controls in Hardy-Weinberg equilibrium (HWE), we similarly observed a decreased lung cancer risk among c1/c2 and c1/c2+c2/c2 carriers (OR=0.73, 95%CI: 0.60-0.88 and OR=0.73, 95%CI: 0.60-0.88, respectively), as compared with c1/c1. Conclusions: Our results suggested that CYP2E1 RsaI/PstI c1/c2 and c1/c2+c2/c2 variants might be a protective factor for developing lung cancer in Chinese population. Further well-designed studies with larger sample size are required to verify our findings.     

CYP1A1 and GSTM1 genetic polymorphisms and lung cancer risk in Caucasian non-smokers: a pooled analysis

Polymorphisms for genes encoding the metabolic enzymes cytochrome P450 1A1 (CYP1A1) and glutathione S-transferase M1 (GSTM1) might contribute to the variability in individual susceptibility to lung cancer. The role of CYP1A1 and GSTM1 in lung carcinogenesis might be more important at low levels of exposure to carcinogens. Non-smokers represent a population at low exposure, however, they are often overlooked because of the small number of cases. We therefore conducted a pooled analysis of 14 case-control studies on lung cancer in Caucasian non-smokers with comparable information on genetic polymorphisms included in the International Collaborative Study on Genetic Susceptibility to Environmental Carcinogens. We pooled the raw data from a total of 302 cases and 1631 controls with random effects models. We also evaluated the possibility of inclusion bias and conducted influence analyses. The odds ratio (OR) of lung cancer for the variant CYP1A1 Ile(462)Val polymorphism (Ile/Val, Val/Val) was 2.99 [95% confidence interval (95%CI) 1.51-5.91]; this effect was stronger on lung adenocarcinoma (OR 4.85, 95%CI 2.03-11.6). After excluding outlying or imprecise studies, we did not observe a significant effect of the CYP1A1 MspI (T(3801)C) polymorphism or GSTM1 null genotype (OR 1.20, 95%CI 0.89-1.63). Furthermore, our analyses suggested a combined effect of the CYP1A1 Ile(462)Val polymorphism and GSTM1 null genotype. The OR for the combination of the CYP1A1 Ile(462)Val variant and GSTM1 null genotype was 4.67 (95%CI 2.00-10.9) compared with the concurrent presence of the CYP1A1 wild-type and GSTM1 non-null genotype. We did not observe a modification of the effect of the GSTM1 null genotype according to exposure to environmental tobacco smoke and urban/rural residence. Our study therefore suggests that the CYP1A1 Ile(462)Val variant allele might play a role in lung carcinogenesis among non-smokers, possibly in combination with the GSTM1 null genotype.     

CYP1A1 Genetic Polymorphisms and Risk for Esophageal Cancer: a Case-control Study in Central China

The purpose of this study was to evaluate the associations of CYP1A1 genetic polymorphisms with the riskof developing esophageal cancer (EC). A case-control study was carried out in a Chinese population in which157 hospital based EC cases and 157 population based healthy controls with 1:1 match by age and sex wereincluded. PCR based restriction fragment length polymorphisms (PCR-RFLP) were used to detect genotypes incase and control groups. For the CYP1A1 Ile/Val polymorphism, comparing with wild genotype Ile/Ile, both theheterozygote genotype Ile/Val and the combined variant genotype Ile/Val+Val/Val increased the risk of esophagealcancer (OR: 2.05, 95%CI: 1.19-3.54, OR: 1.86, 95%CI: 1.11-3.12). No significant association was found betweenthe CYP1A1 MspI polymorphism and EC. According to analysis of combined genotypes, the TC/AG combinedgenotype which contained both variant alleles of these two polymorphisms increased the risk of developing EC(OR: 2.12, 95%CI: 1.16-3.85). Our results suggested that genetic polymorphisms of CYP1A1 may increase thesusceptibility to EC.     

Association of CYP1A1, CYP1A2, GSTM1 and NAT2 gene polymorphisms with colorectal cancer and smoking.

We investigated CYP1A1*2A, CYP1A1*2C, CYP1A2*1C, CYP1A2*1F, GSTM1 and NAT2 gene polymorphisms, involving enzymes which metabolize many carcinogens, with reference to colorectal cancer risk. The distribution of these genotypes was not associated with risk overall. However, the CYP1A1*2A T/C genotype showed a significant association with colorectal cancer risk in never-smokers (odds ratio [OR], 3.06; 95% confidence interval [95% CI], 1.11-8.40; p = 0.030). The risk of the NAT2 rapid genotype in never-smokers was also statistically significantly increased (OR, 5.38; 95%CI, 1.80-16.1; p = 0.003). Furthermore, the joint effects of NAT2 rapid plus other genotypes were associated with colorectal cancer overall (OR, 3.12; 95%CI, 1.15-8.51; p = 0.026, for NAT2 rapid plus combined CYP1A1*2C Ile/Val and Val/Val, OR, 3.25; 95%CI, 1.09-9.74; p = 0.035, for NAT2 rapid plus CYP1A2*1C G/G, and OR, 4.20; 95%CI, 1.09-16.1; p = 0.037, for NAT2 rapid plus GSTM1 null, respectively). In never-smokers, the joint effects of NAT2 rapid plus other genotypes were remarkable (OR, 15.9; 95%CI, 1.87-135.8; p = 0.011, for NAT2 rapid plus combined CYP1A1*2A T/C and C/C, OR, 5.71; 95%CI, 1.49-21.9; p = 0.011, for NAT2 rapid plus combined CYP1A1*2C Ile/Val and Val/Val, and OR, 9.14; 95%CI, 2.05-40.7; p = 0.004, for NAT2 rapid plus CYP1A2*1F A/A, respectively). The joint effect of CYP1A2*1F A/A plus CYP1A2*1C G/G genotypes was also increased in never-smokers (OR, 6.16; 95%CI, 1.26-30.1; p = 0.025). Our findings suggest that the CYP1A1*2A T/C and NAT2 rapid genotypes is associated with colorectal cancer susceptibility without smoking exposure. These results also indicate that the NAT2 in combination with CYP1A1*2C, CYP1A2*1C, or GSTM1 genotypes may strongly confer susceptibility to colorectal cancer. In particular, the combination of NAT2 plus CYP1A1*2A, CYP1A1*2C, or CYP1A2*1F genotypes, and that of CYP1A2*1F plus CYP1A2*1C genotype may define a group of persons who are genetically susceptible to colorectal cancer in never smokers.     

Relationship between CYP1A1 genetic polymorphisms and renal cancer in China

Aim: To study the potential role of cytochrome P450, family 1, subfamily A, polypeptide 1 (CYP1A1) polymorphisms in the risk of renal cell cancer in Chinese. Methods: A total of 181 pathologically-proven renal cancers and 350 controls from the second Xiangya Hospital in Changsha were collected during the period from May 2007 to December 2010. CYP1A1 genetic polymorphisms were genotyped using PCR-RFLP. Unconditional logistic regression analysis was performed to analyze their relationship with risk of RCC. Results: Individuals with Val/Val genotypes had a significantly increased risk of RCC compared those with CYP1A1 IIe/IIe (OR=1.69, 95%CI=1.03-2.85). We also found CYP1A1 Wt/Vt and Vt/Vt to confer a significantly greater risk than CYP1A1 Wt/Wt (Wt/Vt: OR=2.14, 95%CI=1.24-3.45; Vt/Vt: OR=1.78, 95%CI=1.31-3.96). In smokers, a high increase risk of RCC was observed in those with CYP1A1 Val allele and Vt allele (Val allele: OR=2.13, 95%CI=1.40-2.57; Vt allele: OR=3.75, 95%CI=2.43-6.79), but no other significant interactions were found. Conclusion: Our study found suggestive evidence that CYP1A1 polymorphisms may play an important role in the etiology of RCC. Cigarette smoking may increase the susceptibility to RCC carcinogenesis in individuals with a high-risk genotype.     

Association of CYP1A1 and microsomal epoxide hydrolase polymorphisms with lung squamous cell carcinoma

Lung cancer is the leading cause of death among cancers in Taiwan. Although the etiology of lung cancer has yet to be defined, genetic variability in activities of metabolic enzymes has been correlated with lung cancer. In the present study, the possibility of association of CYP1A1 and microsomal epoxide hydrolase (HYL1) genetic polymorphisms with lung cancer was examined among 132 lung cancer patients and 259 controls in Taiwan. No significant association was observed for either CYP1A1 or HYL1 polymorphism alone and the overall incidence of lung cancer after adjusting for age, gender and smoking status. When cases were stratified according to histological type, there was significant association between CYP1A1*2A homozygote and squamous cell carcinoma (SCC) (odds ratio (OR) 2.86; 95% confidence interval (CI) 1.33-6.12). Similarly, the proportion of HYL1 genotypes corresponding to high or normal enzyme activities was higher in SCC than in controls (OR 1.96; 95% CI 1.04-3.70). A combination of susceptible CYP1A1 and HYL1 genotypes was found to be highly associated with lung cancer, especially with SCC (OR 6.76; 95% CI 2.29-19.10). Our results suggest that the combination of CYP1A1 and HYL1 polymorphisms is an important risk factor for lung SCC.