【作者】 陈思东；

【导师】 俞守义；

【作者基本信息】 第一军医大学 ， 流行病学， 2002， 博士

【摘要】 目的：肺癌是全球发病率较高的严重危害人类健康的恶性肿瘤。据我国疾病监测系统的报告，从1990年起，中国人群的肺癌死亡率以每年4.5％的速度上升，估计在未来上升速度会更快。由此可见，肺癌的防治问题将成为目前和未来的重要的公共卫生问题。近二十年来，许多学者在从事肺癌的病因学研究。目前认为吸烟，大气污染和某些特殊职业接触等因素是肺癌的重要的危险因素。但是，流行病学家也日益认识到吸烟和某些职业接触不能很好地解释同一国家中不同地区和不同国家间肺癌发病率的差异。在人们对肺癌的环境病因进行研究的同时，也有一些学者对遗传因素进行研究，大多数的研究是通过家系分析进行研究。研究结果表明，肺癌具有家族聚集性，肺癌的家族史增加个体患肺癌的危险性，而且女性肺癌的遗传易感性较高，但是，这些遗传易感性的分子生物学基础尚未完全明了。 随着分子生物技术的不断发展，许多学者从分子生物学方面去研究肺癌的发生机制，已经发现了许多生物标记物，极大地丰富了对肺癌的发生过程的认识。近年来，肺癌的遗传易感性机制在肺癌发病中的意义引起了人们的重视，近几年来，有不少学者在探讨这一问题，绝大多数研究集中在细胞色素P450与谷胱苷肽酶的基因多态性。目前研究的较多的是CYP1A1，CYP2E1以及GSTM₁等，但是研究结果不一致，这种结果的不一致的原因与研究设计，样本量，潜在混杂因素的处理与否以及是否存在多种基因的联合效应等有关。 目前对细胞色素P450与谷胱苷肽酶的基因多态性与肺癌关系的研究，至少存在三个问题：①这些基因多态性是先天遗传的，还是由于某些暴露刺激后发生突变而形成的?②几个基因突变的联合作用对肺癌风险的关系的研究甚少③缺乏环境因素与基因突变的联合作用与肺癌风险矽失戾勿刎哆已针对这些存在问题，我们在广州地区进行了一项肺癌易感性标记物 CYP，CYPZEI，GSTM1与肺癌发病关系的病例－对照研究，应N＄hqgfrgffN、ffMx－－AlWarHffWbkMffmxMg(NAt：n．nvx＊——————％————方法：应用病例对照研究方法，选择2000年10月一2002年1月在广州市中山医科大学附属第一医院呼吸内科，广州市肿瘤医院，广州市红十字会医院胸外科住院的经病理组织学确诊的未经任何抗癌治疗的原发性肺癌病例gi例。采用1：1配比的方法，配比的条件是同性别，年龄士2岁，居住在广东的广东籍人。选择病例来源的上述医院住院的非肿瘤病人gi例。另外，采用频数配比的方法，选择广东药学院健康职工47人作为另一对照组。 制定统一的调查表，调查内容包括：一般特征、病例的诊断时间、 医诊医院、病理诊断、毒物接触史、吸烟状况、烹调史、使用燃料类型， 有无抽烟机，饮食状况：（牛奶及其制品，豆类制品，蔬菜水果，胡萝卜， 煎炸食品，辛辣食品，甜食，肉类，鱼类等食品的摄入量，）、饮酒、饮 茶、参加体力锻炼情况、心理因素、既往疾病史、家族患癌史等。调查 员直接到医院病房询问病人。 每位病例和对照均采集其静脉血，然后分离血清和血块，用血块提 取DNA。应用PCR－RFLP技术检测CYP IAI，CYPZEI基因，CYPIAI 的PCR产物用MSpl酶切，CYPZEI的PCR产物用RSd酶切，GSTMI 基因多态性采用PCR技术检测。 对调查资料应用SPSS软件进行单因素分析，分层分析，以及多因 素条件lOgistiC回归分析。结果： 一 病例和信息的真实性 本次调查的病例与对照均是在医院病房调查，并在主管病人的医生安排下进行的，这样可以尽量避免调查环境引起的偏倚。尽管如此，为了控制信息偏倚，在研究中，随机抽取了10例病例和10例对照通过病例所在 6医护人员进行第二次调查，比较二次调查的结果，通过计算二次结果的一致性，来评价所得信息的真实性。结果表明两次调查的20种变量中，13个变量的一致率达到100％，只有家庭经济状况为85％，其余6个变量均在95％，可认为本次调查的信息的真实性是好的。 二 病例组与对照组CYPIAI、CYPZEI、GSTMI基因型的分布 及与肺癌风险关系 l·CYP IAI基因型的分布及与肺癌风险关系 MSp互识别的＊＊PIA互基因的三种类型，即突变型(纯合于＼杂合型、野生型。它们在病例组的携带率分别为39．56％，25．27％，32．97％，而对照组则分别为：28．26％，33．33％，38．41％，经统计学检验，两组间的差别无统计学意义（扩司．48，P＞0．05人携带突变型基因者患肺癌的危险是野生型的1．53（0．sl～2．88）倍，但无统计学意义。 2．＊＊NE且基因多态与肺癌风险关系 CICZ（杂合型）变异的危险性最小，以其为参照组与两种纯合型比较进行肺癌风险的分析。结果表明：C1C；基因型的OR为1．71m．95刁．07XCZCZ基因型的OR为5．38（1．42～20．33）。 3．GSTMI基因多态性与肺癌风险的关系 以常见的GSTM；＋（＋什，＋／－）基因型个体的OR为互，GSTM；基因缺失川川）个体的OR值为l．38m．80～更多还原

【Abstract】 Objective: To evaluate the correlation of polymorphisms with CYP1A1Mspl, CYP2E1 Rsal and GSTMi, and environmemtal factors such as smoking, alcohal drinking, tea drinking etc. independently and in combination with the the risk of lung cancer.Methods: A case-control study which included 91 cases of lung cancercollected from the First Affiliated Hospital of Sun Yat-sen University of Medical Sciences, Guangzhou Tumour Hospital and The Red Cross Hospital of Guangzhou, and 138 controls . All subjects were investigated with a uniform questionnaire. The contents of survey included general characteristics such as age, sex, education, etc; habit of smoking, alcohol, tea and special kinds of food such as vegetables, carrot, milk, bean products,fruit, meat, fish,etc; physical exercise; psycho-social factors; family history of lung cancer. Blood samples were collected from all cases and controls for detecting CYP1A1 Msal, CYP2E1 Rsal and GSTM, polymorphisms. The polymorphisms of CYP1A1 Msal, CYP2E1 Rsal and GSTMi were analyzed by PCR based RELP.Results:1. The frequencies of the m2ni2, niinii, n^mi genotypes of CYP1A1 Msal were 39.56%, 25.27%,32.97% respectively in the case group, and 28.26%, 33.33%, 38.41% respectively in the control group. There was no significant13different in frequencies of this three kinds of genotypes between the two groups (P>0.05).2. The risk of suffering from lung cancer was 5.38 times (95%CI 1.42-20.33) in individuals with C2C2 genotype of CYP2E1 Rsal as that in individuals with CiC2 genotype. The risk assocciated with QCi genotype was higher (OR= 1.71, 95%CI 0.95-3.07) than that with C2C2 genotype.3. The rate of GSTMl null(0/0) genotype was higher in the case group than that in control group, with the OR of 1.38(95%CI 0.80-2.38), but there was no statistical significant.4. The results showed that a combination of several genotypes was strongly associated with lung cancer. There was a synergistic interaction between the m2m2 genotype of CYP1A1 Mspl and GSTMl null(0/0) genotype on the elevated susceptibility to lung cancer, and the OR of this two genotypes, compared with minii of CYP1A1 and GSTMi(+/+), was 2.01(95%CI 0.86-4.88). We also observed a synergistic interaction effect between m2m2 genotype of CYP1A1 Msal and CiQ genotype of CYP2E1 Rsal on the risk of lung cancer, with the OR of 3.09(95%CI 1.09-8.72). The CiCi genotype of CYP2E1 Rsal with GSTMl null(0/0) genotype had 2.11-fold risk of lung cancer compared to the CiC2 genotype of CYP2E1 Rsal with GSTMl null(+/+) genotype, but there was no statistically significant difference(P>0.05). The odds ratio for the combination of m2m2 genotype of CYP1A1 Msal, CiCi genotype of CYP2E1 Rsal and GSTMl null(0/0) genotype was 3.68(95%CI 1.08-12.52).5. Although individual polymorphic gene was not associated with the development of lung cancer, the results of analysis on the combined effects between genes and environmental factors showed that there were synergistic interactions between certain genotypes and certain environmental exposures. The odds ratio of smoker with m2m2 genotype of CYP1A1 Msal compared with m2m2 genotype was 2.56(1.05-6.25); the odds ratios of smoker with CiCigenotype, with C1C2 genotype and nonsmoker with CiCi genotype of CYP2E1 Rsal compared with nonsmoker with C]€2 genotype were 3.63(1.37~34.97), 3.27(1.09-9.84), 2.58(0.96-6.91) respectively. The odds ratio of combination of smoking and GSTM1 null(0/0) genotype compared with nonsmoking with GSTM1 (+/+) genotype was 3.07(1.36-6.95), and that of smoker with GSTM1 (+/+) genotype was 2.88(1.22-6.78).The risk of developing lung cancer in smoker with m2m2 genotype of CYP1A1 and GSTMi null (0/0)genotype was significantly higher than that in smoker with minii genotype of CYP1A1 and GSTMi null(0/0) genotype(OR6.33, 95%CI 1.94-24.80). The odds ratio of smoking with m2m2 genotype of CYP1A1 and GSTMi null genotype compared with nonsmoking with m2m2 genotype and GSTMi (+/+) was 4.88(1.07-22.35).6. Alcohol drinking was strongly associa更多还原