中国辽宁汉族群体DNA修复基因: ERCC2/XPD A35931C 遗传多态性

DNA修复基因在保护维持基因组整体性及抗癌发生过程中起着重要作用，DNA修复基因的产物:ERCC2/XPD参与核苷酸切除修复过程。单核苷酸多态的群体遗传学信息对于遗传疾病的研究是非常重要的。我们调查了中国辽宁汉族群体DNA修复基因: ERCC2 A35931C 遗传多态性。ERCC2 A35931C基因型频率：AA=0.95; AC=0.05; CC=0, 基因型分布符合Hardy-Weinberg遗传平衡定律(P=0.77)；ERCC2 A35931C等位基因频率：A=0.98; C=0.02。研究结果与前期所报道的其他群体的该等位基因频率分布进行比较。     

中国北方地区汉族人群MCP-1基因多态性与肺癌相关性研究

目的 探讨中国北方地区汉族人群单核细胞趋化因子蛋白-1(monocyte chemoattrac-tant protein 1,MCP-1)基因-2518位点多态性与肺癌的相关性.方法 应用聚合酶链反应-限制性片段长度多态性(polymerase chain reaction-restriction fragment length polymorphism,PCR-RFLP)的方法对中国北方地区汉族人群134例肺癌患者和82例正常对照进行MCP-1基因-2518位点基因多态性检测.结果 AA基因型和GG基因型频率在肺癌病人和对照组间差异有统计学意义.AA基因型患肺癌的相对风险度增加(OR=2.645,X~2=6.532,P=0.011),GG基因型患肺癌的相对风险度降低(OR=0.519,X~2=4.929,P=0.026).肺癌病人中非小细胞肺癌患者AA基因型和GG基因型频率在病人和对照组间差异有统计学意义,AA基因型患病的相对风险度增加(OR=3.138,X~2=8.905,P=0.003),GG基因型患病的相对风险度降低(OR=0.516,X~2=4.613,P=0.032).小细胞肺癌患者各基因型频率与对照组差异无统计学意义.结论 中国北方地区汉族人群MCP-1基因-2518位点多态性与非小细胞肺癌相关,与小细胞肺癌不相关.     

DNA修复基因多态性与肺癌易感性的研究进展

肺癌是目前世界上死亡率最高的恶性肿瘤,其发病率在世界范围内呈逐年上升趋势。研究表明,DNA修复基因多态性可通过影响机体对DNA损伤的修复能力而使机体罹患癌症的风险发生变化。本文介绍了相关DNA修复基因多态性的研究进展,并就其多态与肺癌易感性的关系作一系统的人群基因组流行病学研究综述。     

DNA修复基因hOGG1多态与食管癌遗传易感性

目的：研究修复８－羟基鸟嘌呤的ｈＯＧＧ１基因Ｓｅｒ３２６Ｃｙｓ多态与中国人食管癌易感性的关系。方法：采用病例－对照分子流行病学方法,以ＰＣＲ－单链构象多态（ｓｉｎｇｌｅ ｓｔｒａｎｄ ｃｏｎｆｏｒｍａｔｉｏｎ ｐｏｌｙｍｏｒｐｈｉｓｍ,ＳＳＣＰ）技术,分析了２０１名正常对照和１９６例食管癌患者ｈＯＧＧ１基因第３２６位Ｓｅｒ／Ｓｅｒ、Ｓｅｒ／Ｃｙｓ和Ｃｙｓ／Ｃｙｓ基因型分布,并比较不同基因型与食管癌风险的关系。结果：正常人群的Ｓｅｒ／Ｓｅｒ、Ｓｅｒ／Ｃｙｓ和Ｃｙｓ／Ｃｙｓ基因型频率分别为３３．８％、５２．８％和１３．４％,而食管癌病例组则分别为３９．８％、３８．８％和２１．４％。虽然两组人群的Ｃｙｓ等位基因频率基本相同（３９．８％４０．８％）,但食管癌病例组的Ｃｙｓ／Ｃｙｓ基因型频率显著高于对照组（Ｐ＜０．０５）     

DNA错配修复基因MSH2和MLH1单核苷酸多态性与食管癌发生风险相关性研究

目的:探讨DNA错配修复基因MSH2和MLH1单核苷酸多态性对于食管癌易感性的潜在作用。方法:采用医院为基础的病例-对照研究方法,应用PCR-RFLP检测包括正常对照132例,食管癌患者169例MSH2c.2063TG和MLH1IVS14-19AG两个基因多态性位点的基因型。通过Logistic回归分析计算出比值比(OR)和95%置信区间(95%CI),估计不同基因型频率分布与食管癌发生风险的关系。结果:MSH2c.2063TG携带突变等位基因个体发生食管癌的风险是非携带者的3.24倍。MLH1IVS14-19AG突变等位基因携带者发生食管癌风险是非携带者的1.58倍。对MSH2和MLH1基因交互作用分析发现两突变基因型携带者发生食管癌风险大大增加并具有显著的统计学意义。结论:DNA错配修复基因MSH2c.2063G突变等位基因和MLH1IVS14-19G突变等位基因可能在促成食管癌发生过程起到一定作用。     

DNA修复基因多态性与肺癌易感性的研究进展

肺癌是目前世界上死亡率最高的恶性肿瘤，其发病率在世界范围内呈逐年上升趋势。研究表明，DNA修复基因多态性可通过影响机体对DNA损伤的修复能力而使机体罹患癌症的风险发生变化。本文介绍了相关DNA修复基因多态性的研究进展，并就其多态与肺癌易感性的关系作一系统的人群基因组流行病学研究综述。     

辽宁汉族人群HLA-DRB1基因多态性分布

目的调查HLA-DRB1基因位点遗传多态性在辽宁汉族人群中的分布。方法应用聚合酶链反应．序列特异性引物方法和反向聚合酶链反应．序列特异性寡核苷酸探针杂交的方法对13265名辽宁汉族人进行中低分辨率HLA-DRB1基因分型。结果共检出HLA-DRB1位点的13种等位基因，其中以HLA-DRB1＊15频率最高（17．49％），其次为HLA-DRB1＊09、＊12和HLA-DRB1＊07，基因频率分别为13．40％、11．87％和11．8l％。HLA-DRB1＊03（18）和HLA-DRB1＊14（8）等位基因未检出。对观察值和期望值进行X^2检验，符合Hardy-Weinberg平衡（X^2=73．34，af=78，P〉0．5）。该人群与南北方汉族人群、日本人、白人和黑人分别进行X^2值检验差异有统计学意义，X^2值分别为112．053、8．514、692．141、70．558和121．755。结论辽宁汉族人群HLA-DRB1基因分布有自身特点。     

FcRL3基因三个单核苷酸多态性与重庆汉族人群Graves病关联研究

目的 了解中国重庆地区汉族人群Fc受体样因子(Fc receptor-like proteins,FcRL3)基因启动子A/G,第2外显子C/G,第4外显子C/T多态性与Graves病(Graves disease,GD)的相关性.方法 采用聚合酶链反应限制性片段长度多态性分析方法结合直接测序技术,对重庆地区无亲缘关系的120名正常人和128例GD患者进行多态性研究,同时进行甲状腺功能和自身抗体的检测,应用Unphased1122和LDA1.0软件进行连锁不平衡和单倍型分析,用卡方检验分析基因型、等位基因和单倍型频率在GD组和对照组之间的差异.结果 GD组FcRL3基因3个多态性位点基因型和等位基因的频率与对照组相比,其差异均有统计学意义(P＜0.05).连锁不平衡分析显示启动子和第2外显子存在连锁不平衡,在构建的3个主要单倍型中,仅H2(G-G)单倍型频率GD组明显高于对照组(50.8%vs 35.8%,P＜0.05).除甲状腺疾病家族史与启动子多态性有关联(P%0.05),余临床特征与FcRL3多态性均无相关.结论 多个位点及单倍型分析提示FcRL3基因启动子A/G,第2外显子C/G,第4外显子C/T多态性可能是中国重庆地区汉族人群GD关联的危险因素.     

p53基因第72位密码子多态与食管癌风险

目的 研究p53基因第７２位密码子Ａrg/Pro多态与食管癌遗传易感性的关系。方法 采用聚合酶链反应－－限制性片段长度多态性方法检测了９１例食管癌患者与２０４名正常对照组的p53 Arg/Pro基因型分布及差异。结果 正常对照组p53 Pro等位基因频率（０.588）与病例组（０.480）比较差异无显著性（Ｐ＝０.11）。但３种p53基因型频率在病例组和对照组的分布差异有显著性，病例组的Ｐro/Pro基因型频率（３９.6％）显著高于对照组（２１.1%）。携带Ｐro/Pro纯合变异基因型者患食管癌的风险比携带Ａrg/Arg纯合野生基因型者高２倍[校正比值比（odds ratio,OR）为２.18,95%可信区间（confidemce interval,CI）为１.10-4.35。杂合子基因型（Ａrg/Pro）与食管癌的遗传易感性无关（校正ＯＲ＝０.84％，９５％ＣＩ＝０.42－１.68）。吸烟增加食管癌风险（ＯＲ＝２.30,95%CI=1.30-4.12)，但与Ｐro/Pro基因型无协同作用。结论 p53基因第７２位密码子纯合突变是中国人的食管癌易感因素。     

中国汉族人群DC-SIGN和DC-SIGNR基因遗传多态性

目的了解中国汉族人群DC-SIGN和DC-SIGNR基因颈区重复序列的遗传多态性分布，获得相应位点的汉族人群的遗传学数据。方法应用PCR技术、琼脂糖凝胶电泳结合测序对DC-SIGN和DC-SIGNR基因的颈区重复序列分型，计算DC-SIGNR的多态信息含量。结果DC-SIGN多态性低，颈区绝大多数为等位基因7重复，该等位基因频率为0．9808，但亦检出少量的等位基因4、5、6、8等变异，而美国白人只含有等位基因6、8变异；DC-SIGNR存在高度多态性，多态信息含量为0．5312，存在4、5、6．7、8、9等位基因，检出16种基因型。6／5、7／4、7／5、7／6、7／7、9／5、9．／7、9／9基因型和5、6、7、9等位基因频率在中国汉族人群和美国白人中的分布构成差异有统计学意义（P〈0．01），与美国白人比较，中国汉族人群似乎存在更多的插入突变。结论中国汉人的DC-SIGN和DC-SIGNR基因型分布和基因频率与美国白人相比其差异有统计学意义，并有其独特的群体遗传学特征。     

DNA修复基因XPC Ala499Val、Lys939Gln多态与肺癌易感性

目的 探讨中国人DNA修复基因XPC Ala499Val、Lys939Gln多态与肺癌易感性的关系。方法 以社区为基础的病例对照研究。经组织学确诊的肺癌病例320例,相同地区年龄和性别频数匹配的人群对照322人,以PER为基础的方法进行多态性检测,比较不同基因型与肺癌风险的关系,并探讨吸烟在其中的影响。结果 与携带499 Ala／Ala基因型者比较,携带至少1个499Val等位基因者（即Ala／Val和Val／Val基因型）肺癌风险增加1．54倍（95％CI=1．11～2．14）,而同时有499和939两个位点变异等位基因者肺癌风险增加2．55倍（95％CI=1．45～4．52）。交互作用分析显示,XPC 499Val变异基因型与吸烟具有超相乘模型的交互作用,同时有两个位点变异等位基因并吸烟者肺癌风险增加可高达7．36倍（95％CI=3．19～17．0）。结论 XPC Ala499Val和Lys939Gln多态可能与中国汉族人群肺癌遗传易感性有关,并可显著增加吸烟对肺癌的危险性。     

Association of NER pathway gene polymorphisms with susceptibility to laryngeal cancer in a Chinese population

We systematically analyzed the association of nine SNPs of seven key NER pathway genes with the development of laryngeal cancer patients, and investigated whether NER pathway polymorphisms could serve as potential biomarkers for laryngeal cancer risk. 271 patients with pathologically proven laryngeal cancer and 271 control subjects were included in our study. Genotyping of ERCC1 rs11615 and rs2298881, ERCC2 rs13181 and rs50871, ERCC3 rs4150441, ERCC4 rs6498486, ERCC5 rs2094258, XPA rs2808668 and XPC rs2228001 were analyzed by polymerase chain reaction (PCR) coupled with restriction fragment length polymorphism (RFLP). By conditional logistic regression analysis, individuals carrying the TT genotype of ERCC1 rs11615 were correlated with an increased risk of larynx cancer when compared with the CC genotype (OR=1.89, 95% CI=1.07-3.37; P value=0.02). Moreover, individuals with the GG genotype of ERCC2 rs50871 were associated with an elevated risk of larynx cancer when compare with the TT genotype (OR=2.03, 95% CI=1.15-3.63; P value=0.01). We found a significant interaction between ERCC2 rs50871 polymorphism and tobacco smoking in the risk of larynx cancer (P for interaction <0.05). In conclusion, our study showed that ERCC1 rs11615 and ERCC2 rs50871 polymorphisms could influence the risk of larynx cancer in Chinese population, particularly among smokers.     

Association between interluekin-17 gene polymorphisms and the risk of cervical cancer in a Chinese population

We conducted a study to analyze the association of three common SNPs of IL-17A rs2275913 and rs3748067 and IL-17F rs763780 gene polymorphisms with the risk of cervical cancer in a Chinese population. Our study included 352 cervical cancer patients and 352 controls between January 2013 and December 2014. Genotyping of IL-17A rs2275913 and rs3748067 and IL-17F rs763780 genes was performed by multiplex PCR assays using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). By χ² test, there was significantly difference in the genotype distribution of IL-17A rs2275913 between cervical cancer patients and control subjects (χ²=11.45, P=0.003). By conditional logistic regression analysis, we found that individuals with the GA and AA genotypes were associated with an increased risk of cervical cancer when compared with the GG genotype in codominant model, and the adjusted Ors (95% CI) were 1.57 (1.13-2.18) and 2.01 (1.15-3.49), respectively. In dominant model, we found that the GA+AA genotype of rs2275913 was correlated with a moderate increased risk of cervical cancer compared with the GG genotype (OR=1.64, 95% CI=1.20-2.24). We only found significant interaction between rs2275913 polymorphism and HPV-16 or 18 infection in the risk of cervical cancer (P for interaction <0.05). In conclusion, our study suggests that IL-17A rs2275913 polymorphism may affect the development of cervical cancer in codominant and dominant models, and this gene polymorphism has interaction with HPV-16 or 18 infection.     

Polymorphisms in the thymidylate synthase promoter and the DNA repair genes XRCC1 and XPD in a Brazilian population

Polymorphisms in genes responsible for maintaining genomic integrity are potential modifiers of disease risk. Since considerable interindividual and interethnic variation in DNA repair capacity has been associated with polymorphic alleles, we evaluated the frequency of the 2R/3R variants in the TS promoter, Arg194Trp and Arg399Gln in the XRCC1 gene, and Asp312Asn and Lys751Gln in the XPD gene in 364 healthy individuals from a Brazilian population separated by ethnicity (European ancestry and African ancestry). The genotypes were determined by PCR (TS) or by PCR-RFLP (XRCC1 and XPD). The frequency of the TS 3R allele was 0.56 for whites and 0.51 for nonwhites. In the case of the XRCC1 MspI polymorphism, the allele frequencies were 0.09 for 194Trp in both nonwhites and whites and 0.27 and 0.28 for 399Gln in nonwhites and whites, respectively. For the XPD 312Asn allele, we found a frequency of 0.25 in white individuals, which was significantly different (P = 0.025) from that seen in nonwhites (0.15). Similarly, the 751Gln polymorphic allele of the XPD gene was significantly more frequent (P < 0.002) in whites (0.30) than in nonwhites (0.20). The genotype frequencies were within Hardy-Weinberg equilibrium. We concluded that the genotype and allele frequencies of XPD gene polymorphism differed between white and nonwhite Brazilians, and that the frequencies of the XPD 312Asn and XRCC1 399Gln alleles in this Brazilian population showed ethnic variability when compared with those observed in other populations.     

CDH1基因-160(C→A) 多态与福建地区中国人群胃癌遗传易感性的关联研究

目的 上皮钙黏着蛋白（E—cadherin）的编码基因CDHI是重要的肿瘤抑制基因，本研究探讨CDH1基因-160（C→A）多态性在福建地区胃癌人群中的分布及其与福建地区胃癌发病风险的相关性。方法 采用聚合酶链反应-变性高效液相色谱分析方法对102例胃癌患者和101名正常对照者进行CDH1基因-160（C→A）多态的基因型分析，比较基因型分布和发病风险的关系；危险度OR及95％CI应用非条件Logistic回归分析计算。结果 CDH1基因-160（C→A）多态的CC、CA、AA基因型在病例组中的分印频率分别为58（56．9％）．38（37．3％），6（5．9％）；在对照组的分布频率分别为55（54．5％），41（40．6％），5（5％）；两组间分布的差异无统计学意义（P〉0．05）。AA基因型没有显著性地提高或降低胃癌的发病危险（OR=1．12；95％CI：0．32～3．95）；携带A等化基因与胃癌的临床病理特征也无关联性。结论 CDH1基因-160（C→A）多态性可能与福建地区中国人群胃癌发生的遗传易感性无关。     

ATM基因rs227060位点单核苷酸多态性与肺癌易感性的相关性

目的:探讨共济失调毛细血管扩张症突变基因(ataxia telangiectasia mutated,ATM)rs227060位点单核苷酸多态性(single nucleotide polymorphisms,SNPs)与肺癌易感性之间的相关性.方法:采用聚合酶链反应-SNP敏感性分子开关方法,检测225例肺癌患者和128例健康体检者ATM基因rs227060多态位点等位基因以及基因型频率分布特点;并应用非条件Logistic回归法统计分析rs227060单核苷酸多态性与肺癌的相关性.结果:rs227060多态位点共检测出CC,CT,TT三种基因型和C,T两种等位基因,其在肺癌组与对照组的基因型分布频率为:CC基因型17.3％与29.7％、CT基因型61,4％与59.3％、TT基因型21.3％与11％,两组间基因型频率和等位基因频率分布差异均有统计学意义(P＜0.05).在对ATM rs227060基因型的多态性分析过程中发现:吸烟史在肺癌组与对照组相比差异无统计学意义(P＞0.05),而年龄、性别、肿瘤家族史在肺癌组与对照组相比差异均有统计学意义(P＜0.05);且以CC基因型作为对照,携带TT基因型的个体患肺癌的风险是携带CT基因型个体的3.49倍(OR=1.829;95％CI:1.045～3.199).结论:ATM基因rs227060位点单核苷酸多态性与肺癌易感性存在相关性,且携带TT基因型可增加肺癌的发病风险.     

CDT1和GMNN基因多态性与女性乳腺癌危险性的关联研究

目的探讨参与DNA复制的两个重要基因CDTI和GMNN基因多态性与我国人群散发乳腺癌的关联。方法采用病例对照研究设计，研究对象包括427例乳腺癌患者及477名无肿瘤史的正常对照组。采用聚合酶链反应-限制性片段长度多态性，方法测定CDT 1838G／A，错配聚合酶链反应-限制性片段长度多态性方法测定GMNN 387C／A的基因型。结果CDT1GG、GA和AA3种基因型以及GMNN CC、CA和从3种基因型在病例组和对照组的频率分布差异无统计学意义（P值分别为0．619和0．793）。然而，分层分析发现，在有肿瘤家族史的人群中，CDT1 GA＋AA基因型可显著增加乳腺癌的危险性（调整OR：2．21，95％CI：1．20～4．09）。结论CDT1 838G／A基因多态性和GMNN 387C／A基因多态性与总的散发性乳腺癌无显著关联，但CDT 1838G／A可能对于具有遗传背景的女性乳腺癌的易感性具有一定的作用。     

DNA repair gene XRCC1 and XPD polymorphisms and the risk of idiopathic azoospermia in a Chinese population

Genetic polymorphisms in DNA repair genes may influence individual variation in DNA repair capacity and further influence the risk of developing cancer. However, little information is available on these polymorphisms in infertility. To investigate whether polymorphisms in DNA repair genes, X-ray repair cross-complementing group 1 (XRCC1) and xeroderma pigmentosum group D (XPD), alone or in combination, are associated with the risk of developing idiopathic azoospermia, the genotype and allele frequencies of three observed polymorphisms (XRCC1 Arg194Trp and Arg399Gln, and XPD Lys751Gln) were examined by polymerase chain reaction-restriction fragment length polymorphism based on a Chinese population consisting of 171 idiopathic azoospermia patients and 247 normal-spermatogenesis fertile controls. Associations between the polymorphisms and the idiopathic azoospermia risk were estimated by logistic regression, and the Statistical analysis system was used to test the gene-gene joint effects. All observed polymorphisms were in agreement with Hardy-Weinberg equilibrium. The XPD 751Gln allele seemed to be a risk allele for azoospermia, with a frequency of 11.40% in the cases and 5.67% in the controls (p=0.004). Compared with the Lys/Lys genotype, the XPD 751 Lys/ increased 5.100- or 3.064-fold, respectively, when combined with the XRCC1 194 Arg/Arg or 399 Arg/Arg genotype. In conclusion, our study provided the first evidence that the XPD and XRCC1 polymorphisms contributed to the risk of developing idiopathic azoospermia in a selected Chinese population.     

Assoication of XRCC1 gene polymorphisms with risk of non-small cell lung cancer

DNA repair genes is a key factor for cancer susceptibility, and we conducted a case-control study to investigate the association of XRCC1 codons 194 (Arg to Trp), 280 (Arg to His) and 399 (Arg to Gln) with risk of NSCLC. 210 NSCLC patients and 210 health control subjects were randomly selected from Huaihe Hospital between January 2012 and June 2014. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was taken to assess the genotyping of XRCC1 Arg194Trp, Arg280His and Arg399Gln. By multivariate logistic regression analysis, we found individuals carrying with Trp/Trp and Arg/Trp + Trp/Trp genotypes were associated with a significantly increased risk of NSCLC compared with Arg/Arg genotype, and the OR (95% CI) were 3.15 (1.32-8.09) and 1.52 (1.02-2.28), respectively. The potential association of Arg/Trp+ Trp/Trp genotype of XRCC1 Arg194Trp with the risk of NSCLC is more evidence in smokers, and the OR (95% CI) was 1.78 (1.01-3.24). In conclusion, we found that XRCC1 Arg194Trp polymorphism may be associated with NSCLC risk, especially in smokers.