北京地区汉族人群DNA修复基因XPD单核苷酸多态性与肺癌及食管癌风险的研究

目的：研究核苷酸切除修复基因XPD单核苷酸多态性与北京地区汉族人群肺癌及食管癌风险的关系。方法：采用以医院患者为基础的病例－对照研究方法，包括正常对照383人，肺癌患者351例，食管癌患者325例。以聚合酶链反应－限制性片段长度多态性方法分析了XPD基因Asp312 Asn和Lys751Gln多态性，比较不同基因型与肺癌及食管癌风险的关系，并探讨吸烟与基因多态交互作用对患癌风险的影响。结果：与携带312 Asp/Asp基因型者比较，携带至少1个312Asn等位基因者（即Asp/Asn和Asn/Asn基因型）罹患肺鳞癌的风险增加1．8倍（95％CI1．10－2．93），而与肺腺癌无关（校正的比值比为1．07，95％CI0．55－2．08）。分层分析显示，风险型等位基因312Asn和751Gln与吸烟有明显的交互作用。吸烟剂量≥29包／年且携带312Asn或751Gln者罹患肺鳞癌的风险最高，校正的比值比分别为12．44（95％CI4．97－31．17）和10．74（95％CI4．51－25．57）。XPD基因Asp312Asn和Lys751Gln多态与食管鳞癌风险无关。结论：XPD基因Asp312Asn和Lys751Gln多态是地区汉族人群肺鳞癌遗传易感因素，而与肺腺癌以及食管鳞癌风险无关，可能反映了不同组织学类型肺癌以及肺癌和食管癌之间的病因学差异。     

Prognostic importance of DNA repair gene polymorphisms of <Emphasis Type="Italic">XRCC1</Emphasis> Arg399Gln and <Emphasis Type="Italic">XPD</Emphasis> Lys751Gln in lung cancer patients from India

Purpose Inter individual variation in lung cancer susceptibility may be modulated in part through genetic polymorphisms in the DNA repair genes, especially the genes involved in the Base Excision Repair (BER) and nucleotide excision repair (NER) pathway. Two of the genetic polymorphisms, XRCC1Arg399Gln and XPD Lys751Gln have been extensively studied in the association with lung cancer risk, although published studies have been inconclusive. Methods In order to verify the role of the common variant alleles in the XPD gene, we have genotyped 211 lung cancer patients and 211 healthy controls using PCR-RFLP assays in a hospital based, case-control study in an Indian population. Logistic regression models were fit to examine the relationship between the log odds of lung cancer and each covariate. Overall Survival in relation to various genotypes and clinicopathological factors were analyzed using Kaplan Meier estimates and hazard ratios were calculated using Cox Regression analysis. Results The carriers of XRCC1 399 AA genotypes were at higher risk of lung cancer (OR = 2.1, 95% CI:1.224–3.669, P = 0.007) than carriers of GG genotype. Subjects carrying 751 AC genotype were at an increased risk of carcinoma of the lung (OR = 1.8; 95% CI:1.233–2.807, P = 0.003) than subjects with AA genotypes. Compared to the XRCC1 399 GG/ XPD 751 AA reference genotype, the combined variants, XRCC1 399 GG/ XPD 751 AC+CC (OR = 1.9, 95% CI: 1.037–3.481), P = 0.03), XRCC1 399 GA+AA/ XPD 751 AA (OR = 1.7, 95% CI: 1.020–2.833, P = 0.04), XRCC1 399 GA+AA/XPD 751 AC+CC (OR = 2.7, 95% CI: 1.582–4.864, P = 0.01), had significantly higher odds ratios. Increasing numbers of either XPD or XRCC1 variant alleles were associated with shorter overall survival, the risk being significant for the XRCC1 gene polymorphism (P = 0.01 by log-rank test). The hazard of dying was significant for the XRCC1 399 AA genotype (HR = 3.04, 95%CI: 1.393–6.670, P = 0.005). Higher tumour stage also came out as significant predictors of patient death. Conclusions These findings suggest that genetic polymorphisms in the DNA repair genes may modulate overall lung cancer susceptibility and that pathological stage and XRCC1 Arg399Gln independently predicted overall survival among Indian lung cancer patients.     

XPD基因单核苷酸多态性与食管鳞状细胞癌、贲门腺癌发病风险的关联研究

目的：探讨DNA修复基因XPD第10外显子Asp312Asn及第23外显子Lys751Gln单核苷酸多态性（SNP）与河北省食管癌、贲门癌高发区磁县和涉县人群食管鳞状细胞癌（ESCC）、贲门腺癌（GCA）发病风险的关系。方法：采用聚合酶链反应．限制性片段长度多态性（PCR-RFLP）分析方法检测327例ESCC患者、253例GCA患者和612例健康对照的XPD基因第10外显子Asp312Asn及第23外显子Lys751Gln的SNP基因型，并比较不同基因型以及单体型与ESCC、GCA发病风险的关系。结果：ESCC、GCA患者组中消化道肿瘤家族史阳性个体比例明显高于对照组，上消化道肿瘤家族史可增加ESCC、GCA的发病风险（经性别、年龄、吸烟状况校正后的OR=1．80和1．75，95％CI=1．36～2．38和1．29～2．36）。根据吸烟状况和上消化道肿瘤家族史进行分层分析发现，与A／A基因型相比，携带C等位基因（A／C或C／C基因型）可显著降低非吸烟个体GCA的发病风险（经性别、年龄和上消化道肿瘤家族史校正后的OR=0．50，95％CI=0．26～0．98）。结论：XPD基因Asp312Asn、Lys751Gln SNP可能与河北省食管癌、贲门癌高发区磁县和涉县人群ESCC、GCA的发病风险无关，但分层分析发现携带第23外显子A／C或C／C基因型可能降低非吸烟个体GCA的发病风险。     

XPD基因多态性与非吸烟女性肺癌易感性的关系

背景与目的 着色性干皮病互补基因D（xeroderma pigmentosum group D，XPD）是一种重要的DNA损伤修复基因，其常见的多态是位于751密码子的A→C多态。本研究旨在探讨XPD基因751位点单核苷酸多态性与非吸烟女性肺癌易感性的关系，并探讨油烟暴露与基因多态性交互作用对肺癌风险的影响。方法 采用病例-对照研究方法，纳入非吸烟女性肺癌患者105人和对照105人。以聚合酶链反应-限制性片段长度多态性方法分析XPD基因Lys751Gln多态基因型。结果 携带至少1个751Gln等位基因者患肺癌的风险显著增高，调整OR为2．80（95％CI为1．21～6．48）。携带等位基因751Gln又有油烟暴露的个体患肺癌的风险较两个危险因素单独作用时更高，校正OR为6．85（95％CI为1．69～27．67，P=0．007）。结论 XPD基因Lys751Gln多态是非吸烟女性肺癌的遗传易感因素。携带XPD751Gln等位基因又有油烟暴露的非吸烟女性患肺癌的风险明显增高。     

野生型XPD转染对胆管癌QBC939细胞生物学行为的影响

目的:探讨野生型XPD基因对人胆管癌QBC939细胞的生物学影响. 方法:用碱裂解法提取空载质粒pEGFP-N2和重组质粒pEGFP-N2-XPD,提取出的质粒以KPNⅠ、BGIⅡ和SPHⅠ酶切鉴定.实验分4组,重组质粒pEGFP-N2-XPD组、空载质粒pEGFP-N2组、脂质体组,并用具有相同遗传背景和代数的QBC939细胞作为空白对照.用脂质体转染法瞬时转染四组细胞.荧光显微镜下观察转染后绿色荧光蛋白报告基因表达情况.提取各组细胞总RNA,合成cDNA,用聚合酶链反应(PCR)检测4组细胞中XPD、p53、cyclin D1、c-myc表达情况.并用四甲基偶氮唑盐(MTT)和流式细胞仪检测细胞增殖及其细胞周期的变化. 结果:pEGFP-N2-XPD细胞与pEGFP-N2、脂质体组和空白对照组相比,XPD mRNA表达量明显增加(0.778±0.018 vs 0.561±0.039,0.544±0.035,0.542±0.034,均P<0.01).pEGFP-N2-XPD细胞中p53 mRNA相对表达量与pEGFP-N2、脂质体组和空白对照组比较具有统计学意义(0.421±0.019 vs 0.256±0.014,0.267±0.015,0.274±0.018,均P<0.01).pEGFP-N2-XPD细胞与其他组相比,cyclin D1 mRNA相对表达量明显降低(0.339±0.041 vs 0.560±0.039,0.558±0.050,0.560±0.041,均P<0.01).pEGFP-N2-XPD细胞与其他组相比,c-myc mRNA相对表达量明显降低(0.355±0.045 vs 0.570±0.075,0.560±0.041,0.537±0.050,均P<0.01).流式细胞仪检测pEGFP-N2-XPD组细胞周期G1期为81.65%,S期为11.83%,其他组G1期分别为65.54%、56.61%、63.26%;S期分别为24.10%、29.52%、27.28%,结果具有统计学意义(P<0.05).MTT检测示pEGFP-N2-XPD细胞生长率为0.249±0.02,与其他组相比,细胞增殖力明显减弱(P<0.01). 结论:野生型XPD基因可以抑制胆管癌细胞的生长,XPD基因可抑制c-myc、cyclin D1基因的表达,增加p53基因表达.     

在晚期非小细胞肺癌中XRCC1和XPD基因多态性的联合和铂类化疗的关系

目的探讨DNA修复基因XRCC1和XPD两种基因多态性的联合与接受铂类治疗的非小细胞肺癌（NSCLC）患者临床疗效及生存时间的关系。方法对接受铂类治疗的108例ⅢB期和Ⅳ期NSCLC患者,利用聚合酶链反应（PCR）结合限制性片段长度多态性（RFLP）来检测XRCC1第399位点和XPD第751位点基因多态性,通过电话随访等方式获得患者的生存状态,以STATA软件分析比较基因多态性与铂类化疗疗效及生存时间的关系。结果在所有接受含铂药物治疗的患者中,化疗总有效率为21.6%。携带XRCC1 Arg/Gln基因型和XPD Lys/Gln基因型的患者有更高有效率（33.33%）,但此类患者与其他各种基因型患者相比,化疗有效率的差异无统计学意义（P〉0.05）。Cox比例风险模型显示,携带XRCC1 Arg/Gln基因型和XPD Lys/Gln基因型的患者中位生存时间（MST）最长35.5个月,但与其他基因型患者相比,MST差异无统计学意义（P〉0.05）。结论同时携带XRCC1 Arg/Gln和XPD Lys/Gln基因型的NSCLC患者,使用含铂方案化疗可能有更高的有效率和更长的生存期。但此结果仍需扩大样本进一步验证。     

ERCC1、ERCC2的多态性对常见消化系统肿瘤的影响

机体DNA修复系统如核苷酸切除修复在维持基因组功能整体性、修复致癌因素所致的损伤及抗癌过程中有着重要作用。一些核酸修复基因,如切除修复交叉互补基因1(ERCC1)及人类着色性干皮病基因D(XPD/ERCC2)的水平下降,可能会成为某种或某几种肿瘤的易感因素;但如果此种基因的水平较高,修复损伤的能力提高,对化疗药物所致基因损伤的修复能力也就增强了,那么可能对化疗药物产生耐药现象。以上两种基因的单核苷酸多态与以DDP、5-FU为基础的化疗方案的疗效存在一定关系,而消化道肿瘤又多应用铂剂及5-FU治疗,故本文对ERCC1、XPD/ERCC2与几种常见消化道肿瘤的发生及其化疗疗效的关系予以综述。     

DNA repair gene XRCC1 and XPD polymorphisms and their association with coronary artery disease risks and micronucleus frequency

Coronary artery disease (CAD) is a multifactorial process that appears to be caused by the interaction of environmental risk factors with multiple predisposing genes. In this study, we investigated the effects of the XPD Lys751Gln and XRCC1 Arg399Gln polymorphisms on the presence and the severity of CAD. We also investigated the presence of DNA damage in the peripheral lymphocytes of patients with CAD by using the micronucleus (MN) test and the effect of XPD Lys751Gln and XRCC1 Arg399Gln polymorphisms on this damage. The study population consisted of 147 patients with angiographically documented CAD and 48 healthy controls. No association between XPD Lys751Gln or XRCC1 Arg399Gln polymorphisms and the presence or the severity of CAD was observed. On the other hand, a significantly higher frequency of MN was observed in CAD patients compared with controls (5.7 ± 1.9 vs 5.0 ± 2.1, respectively, P = 0.018). We found an elevated frequency of MN in CAD patients with the XPD 751Gln allele (Gln/Gln genotype) or the XRCC1 399Gln (Arg/Gln or Gln/Gln genotypes) allele compared with the XPD 751Lys (Lys/Lys genotype) allele or XRCC1 399 Arg (Arg /Arg genotype) allele, respectively. These preliminary results suggest that XPD Lys751Gln and XRCC1 Arg399Gln polymorphisms may not be a significant risk factor for developing CAD. In addition, our results indicate that the MN frequency is associated with presence, but not severity, of CAD and is related to the XRCC1 Arg399Gln and XPD Lys751Gln polymorphisms, suggesting an elevated frequency of MN in CAD patients with the XPD 751Gln or XRCC1 399Gln alleles.     

DNA修复基因XPD单核苷酸多态性和环境因素的交互作用与肝细胞癌的关联研究

目的 探讨XPD基因751、312位点单核苷酸多态性和环境因素的交互作用与肝细胞癌的关系.方法 采用以医院为基础的病例对照研究方法,运用TaqMan MGB荧光定昔实时PCR分析方法对病例组300例肝细胞癌患者和对照组312例非肿瘤患者进行XPD基因751和312位点的基因型分析.以非条件logistic回归模型分析比较各基因型在两组中分布频率的差异,以及基因多态性和环境因素的交互作用.结果 XPD基因751位点3种基因型AA、AC、CC在病例组和对照组中的分布差异无统计学意义(P>0.05),与携带XPD751野生纯合子AA基因型者比较,携带XPD751AC或CC基因型者患肝细胞癌风险无显著增加(P>0.05).XPD基因312位点3种基因型GG、GA、AA在病例组和对照组中的分布差异有统计学意义(P<0.01).与携带XPD312野生纯合子GG基因型者比较,携带XPD312 AA基因型个体罹患HCC的风险是携带XPD312 GG基因型的2.67倍(OR=2.67,95%CI:0.431～16.537),但差异无统计学意义;携带至少一个XPD312A等位基因的个体罹患肝细胞癌的风险是GG基因型的2.62倍(95%CI:1.626～4.222),且差异有统计学意义.交互作用分析结果表明XPD基因751位点多态性与吸烟、XPD基因312位点多态性与吸烟、XPD基因312位点多态性与HBsAg阳性之间在肝细胞癌发生中存在交瓦作用,交互作用的OR值分别为4.291、5.341、7.348.结论 DNA修复基因XPD312A等位基因可能是广西南部地区人群肝细胞癌的危险等位基因,XPD基因多态性与吸烟、HBsAg阳性之间在肝细胞癌发生中存在交互作用,能增加罹患肝细胞癌的风险.