DNA修复基因多态性与肺癌顺铂化疗敏感性的研究

目的:研究切除修复交叉互补基因1(excision repair cross-complementing gene 1,ERCC1)Asn118Asn、切除修复交叉互补基因2(excision repair cross-complementing gene 2,ERCC2)Lys751Gln和X线修复交叉互补基因1(X-ray repair cross complementing group 1,XRCC1)Arg399Gln单核苷酸多态性与非小细胞肺癌(non-small cell lung cancer,NSCLC)对铂类药物化疗敏感性的相关性。方法:采用基因测序的方法,检测89例以铂类药物为主要化疗方案的NSCLC患者外周血DNA中ERCC1基因Asn118Asn、ERCC2基因Lys751Gln和XRCC1基因Arg399Gln的基因型;采用统计学方法分析不同基因型与化疗疗效的相关性。结果:89例NSCLC患者采用铂类药物化疗总有效率为29.2%;ERCC1基因Asn118Asn和ERCC2基因Lys751Gln基因型在化疗有效组和无效组之间的分布,差异无统计学意义(P>0.05);而携带XRCC1基因Arg399Arg与携带至少1个Gln等位基因(Arg399Gln和Gln399Gln)基因型患者的有效率分别为76.9%和23.1%(χ2=11.1,P=0.001)。携带XRCC1基因Arg399Arg基因型患者对化疗的敏感性明显高于携带至少1个Gln等位基因型的患者(比值比为5.228,95%可信区间为1.776～15.387,P=0.003)。ERCC1、ERCC2和XRCC1基因型的联合可以提高化疗的有效率。结论:ERCC1、ERCC2和XRCC1基因的单核苷酸多态性的联合可能与NSCLC对铂类药物化疗敏感性具有相关性。     

非小细胞肺癌RAD51、ERCC2和BAG-1基因多态性的表达

目的:研究DNA修复基因RAD51和着色性干皮病基因(ERCC2/XPD)以及Bcl-2结合抗凋亡基因1(Bcl-2 associated athanogene 1,BAG-1)基因多态性与非小细胞肺癌(non-small cell lung cancer,NSCLC)遗传易感性的关系。方法:采用病例对照研究设计,选取100例非小细胞肺癌病例和80例正常对照。以ERCC2/XPD Lys751Gln和RAD51 codon 135以及BAG-1codon 324基因多态性为研究位点,聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法对多态性进行检测。应用Logistic回归计算OR值及95%CI,比较不同基因型与NSCLC发病风险的关系。结果:ERCC2/XPD 751基因型在病例组的分布频率为C/C型69例(69%)、C/A型26例(30%)和A/A型5例(5%)。与野生基因型C/C型相比,携带ERCC2/XPD C/A基因型和A/A基因型者患NSCLC的危险度比值比(odds ratio,OR)分别是1.53(95%CI:1.15-3.32)和0.58(95%CI:0.15-2.39)。BAG-1 codon 324基因型的分布频率为C/C型81%(81/100)、C/T型19%(19/100)以及T/T型0%(0例)。与野生基因型C/C型相比,携带BAG-1 C/T基因型者患NSCLC的OR是1.28(95%CI:1.08-2.74)。RAD51 codon 135基因型的分布频率为G/G型67%(67/100)、G/C型33%(33/100)、未现C/C型。与野生基因型G/G型相比,RAD51 G/C基因型者患NSCLC的OR是1.03(95%CI:1.06-2.29)。分析结果提示吸烟、环境危险因素与XPD Lys751Gln基因多态存在交互作用,交互效应OR值分别为2.24(95%CI:1.18-2.87)和2.53(95%CI:1.71-3.46),携带XPD Ly s751Gln突变基因者若同时暴露于吸烟、环境危险因素下,则患NSCLC的危险显著增加,相较未暴露于上述因素者,OR值均增大。结论:BAG-1和ERCC2/XPD以及RAD51基因多态性可能与当地居民NSCLC遗传易感性有关,ERCC2/XPD与吸烟、饮酒、环境危险因素存在交互作用。     

XPD Lys751Gln多态性与成年人急性白血病发病风险的关系研究

目的 探讨核苷酸切除修复基因XPD Lys751Gln多态性与成年人急性白血病(AL)发病风险的关系.方法 按照1∶1配对病例对照研究方法,选择100例成年人AL患者为病例组,100名健康体检人群为对照组,采用聚合酶链反应-限制性片段长度多态性方法检测观察对象外周血XPDLys751Gln基因多态性.结果 成年人AL病例组和对照组Lys/Lys、Lys/Gln、Gln/Gln基因型分布频率分别为83%、16%、1%和90%、10%、0,两组比较差异无统计学意义(x2=1.44,P=0.49);携带XPDLys751Gln突变基因(Lys/Gln+Gln/Gln)的个体不增加AL的发病风险(x2=2.10,P=0.15,OR=1.84;95%CI0.80～4.25).按FAB形态学分型,携带XPD Lys751 Gln突变基因型(Lyg/Gln+Gln/Gln)个体患AL的危险度增加(OR=2.77,95%CI0.99～7.73).结论 XPD Lys751Gln可能与成年人急性淋巴细胞白血病的发病风险有关.     

XPD751基因多态性与胃癌易感性的Meta分析

目的探讨XPD 751基因多态性与胃癌患病风险的关系。方法检索VIP、CBM、CNKI、Pubmed、EMBASE等数据库,收集有关XPD Lys751Gln基因多态性与GC易感性的病例对照研究,提取纳入文献的相关数据进行Meta分析。以病例组及对照组XPD Lys751Gln基因型分布的比值比(odds ratio,OR)为效应指标,对文献进行异质性检验,应用Rev Man 5.14软件对数据进行合并分析,计算合并OR值及95%可信区间(CI)。结果共14个病例对照研究符合纳入标准,累计病例2852例,对照6424例。Meta分析结果显示:Gln-allele与GC易感性无关联性(P>0.05);亚组分析:中国人群[Gln/Gln vs.Lys/Lys,OR=3.23(95%CI=2.28-4.56,I2=0%,P<0.001);Gln/Gln vs.Lys/Gln+Lys/Lys,OR=2.42(95%CI=1.74-3.38,I2=0%,P<0.001);Gln-allele vs.Lys-allele,OR=1.28(95%CI=0.81-2.02,I2=88%,P=0.28)];混合人群组各基因型之间比较,均无统计学差异(P均>0.05)。结论 XPD 751Gln/Gln基因型可能是中国人群GC的易感基因型,尚需要开展更大、更严谨的研究证实。     

DNA修复基因XPD单核苷酸多态与胆道癌遗传易感性

目的:研究核苷酸切除修复基因XPDAsp312Asn位点以及Lys751Gln位点多态与上海市区人群胆道癌风险的关系。方法:采用全人群病例-对照研究的方法运用PCR-RFLP对443名胆道癌患者和448名正常对照进行基因型分析。比较各基因型在病例与对照中分布频率的差异,并探讨基因、环境因素在胆道癌发生过程中的作用。结果:与携带XPD 751Lys/Lys基因型者比较,携带Gln/Gln基因型者罹患胆道癌的风险显著增加(校正OR=6.32;95%CI=1.16~34.53)。按解剖部位分析显示,风险增高只限于壶腹部癌(校正的OR=13.17;95%CI=1.71~101.38)。携带312Asn/Asn基因型者罹患壶腹部癌的风险显著高于携带Asp/Asp基因型者(校正后OR=20.09;95%CI=1.13~357.99)。在不伴有胆石症人群中,751Gln/Gln基因型携带者罹患胆道癌风险增加(校正后OR=5.92;95%CI=1.05~33.36),提示在不伴有胆石症人群中,遗传因素可能是发生胆道癌的影响因素。而在饮酒人群中携带751Lys/Gln或Gln/Gln基因型者较携带Lys/Lys基因型者患胆道癌风险增加约3倍。结论:XPD 312Asn等位基因以及751Gln等位基因可能是中国上海地区人群胆道癌尤其是壶腹部癌风险的遗传易感因素。     

XRCC1 Arg399Gln位点多态性与乳腺癌易感性的Meta分析

[目的]评估X射线交叉互补修复基因1(X-ray repair cross complementing protein 1,XRCC1)基因Arg399Gln位点单核苷酸多态性与高加索及亚洲人群乳腺癌(breast cancer,BC)易感性的关系。[方法]检索Pub Med、Embase、中国期刊全文数据库(CNKI)、万方数据库、中国生物医学文献数据库(CBM)和中文科技期刊全文数据库(VIP)等数据库,获取有关XRCC1 Arg399Gln位点多态性与高加索及亚洲人群乳腺癌易感性关系的病例对照研究的资料,以病例组及对照组XRCC1 Arg 399Gln等位基因分布的比值比(OR)为效应指标,应用Meta分析软件Review Manager(version 5.0.10)对各研究原始数据进行统计处理及异质性检验,计算合并OR值及其95%可信区间。[结果 ]共纳入24项病例对照研究,包括15151例乳腺癌患者和17179例对照。Meta分析结果显示,XRCC1 Arg399Gln位点Gln/Gln突变型可能会增加亚洲人群乳腺癌的发病风险[Gln/Gln vs.Arg/Arg亚洲组:OR=1.20(95%CI:1.03~1.39),P=0.02;Gln/Gln vs.Arg/Arg+Arg/Gln亚洲组:OR=1.20(95%CI:1.04~1.38),P=0.01。Gln/Gln vs.Arg/Arg OR=1.01(95%CI:0.94~1.09),Z=0.35,POR=0.73;Gln/Gln+Arg/Gln vs.Arg/Arg OR=1.02(95%CI:0.95~1.09,Z=0.58,POR=0.56;Gln/Gln vs.Arg/Arg+Arg/Gln OR=1.01(95%CI:0.95~1.08),Z=0.33,POR=0.74)。[结论]XRCC1 Arg399Gln位点Gln/Gln突变型可能与亚洲人群乳腺癌易感性相关。     

广西扶绥县肝癌家系XRCC1基因Arg399Gln多态性与肝细胞癌的遗传易感性

目的研究广西扶绥县肝癌家系人群DNA修复基因XRCC1Arg399Gln多态性与肝细胞癌（HCC）遗传易感性的相关性。方法采用病例-对照研究方法,对扶绥县21个肝癌家系人群和10个正常家系人群,运用PCR-RFLP方法分析XRCC1基因Arg399Gln位点多态性,并应用Logistic回归模型分析该位点多态性与肝细胞癌遗传易感性的关系。结果通过XRCC1Arg399Gln基因型检测分型,肝癌家系人群携带变异等位基因Gln的频率为23.68%,正常家系人群为13.16%,等位基因在两组间的分布差异无统计学意义（P〉0.05）。基因型分布符合Hardy-Weinberg平衡定律。正常家系人群中携带Arg/Gln者发生HCC的风险是携带Arg/Arg者的1.622倍（95%CI=0.475～5.541,P=0.440）。肝癌家系人群中除肝癌患者外,携带Arg/Gln、Gln/Gln者发生HCC的风险分别是携带Arg/Arg者的1.198倍（95%CI=0.362～3.968）和2.964倍（95%CI=0.434～20.220,P分别为0.768、0.267）。结论广西扶绥县肝癌家系人群中,XRCC1399Arg/Gln基因型和Gln/Gln基因型者患HCC的风险较Arg/Arg基因型者有增加的趋势,但不存在显著相关性。     

ERCC2、RAD51和BAG-1基因多态性与晚期非小细胞肺癌铂类化疗敏感性的研究

目的:研究着色性干皮病基因(ERCC2/XPD)、DNA修复基因RAD51 codon 135以及Bcl-2结合抗凋亡基因1(Bcl-2 associated athanogene 1,BAG-1)codon 324多态性与晚期非小细胞肺癌(non-small cell lung cancer,NSCLC)以铂类药物为基础的化疗敏感性的关联。方法:选取100例晚期NSCLC患者,使用PCR-RFLP方法检测ERCC2/XPD Lys 751 Gln、RAD51 codon 135以及BAG-1 codon 324基因多态性,应用非条件Logistic回归计算OR值及95%CI,分析不同基因型与化疗敏感性的关系。结果:100例晚期NSCLC患者中,ERCC2/XPD 751基因Lys/Lys、Lys/Gln、Gln/Gln基因型的分布频率分别为69例(69%)、26例(26%)和5例(5%);RAD51 codon 135的基因型频率分布为G/G型占67%(67/100)、G/C型33%(33/100)、未发现C/C型;BAG-1 codon 324基因型频率分布C/C型占81%(81/100)、C/T型占19%(19/100),未发现T/T型。100例NSCLC患者化疗后,其中完全缓解(CR)、部分缓解(PR)、稳定(SD)和进展(PD)患者分别为0、31、41和28例。ERCC2/XPD C/A基因型多态性与化疗敏感性具有相关性(OR=3.53,95%CI=1.58-11.46,P<0.01);BAG-1 codon 324 C/C型患者与C/T型患者的化疗有效率差异有统计学意义(P=0.036),携带C/C基因型患者比C/T基因型患者化疗敏感(OR=2.67,95%CI=1.16-8.23,P<0.05);RAD51 codon 135G/C基因型患者是G/G基因型患者化疗敏感性的2.12倍(OR=2.12,95%CI=1.08-7.41,P<0.05)。结论:ERCC2/XPD、BAG-1 codon 324以及RAD 51 codon 135基因多态性可能与晚期NSCLC铂类药物化疗敏感性有关。     

DNA修复基因XPD 312 Asn和751Lys多态性与非吸烟女性肺癌的关系

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颠换和312密码子G→A转换。本研究旨在探讨XPD基因751位点和312位点单核苷酸多态性与非吸烟女性肺癌易感性的关系。方法 采用病例-对照研究方法,纳入非吸烟女性肺癌患者222人和对照222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和Asp312Asn多态基因型。结果 携带至少1个751Gln等位基因者和携带至少1个312Asn等位基因者患肺癌的风险均显著增高,调整OR分别为3.36(95%CI为2.29-4.90)和1.83(95%CI为1.16-2.91)。结论 XPD基因Lys751Gln和Asp312Asn多态是非吸烟女性肺癌的遗传易感因素。     

XRCC1 Arg399Gln位点多态性和结直肠癌易感性关系的Meta分析

[目的]探讨X射线交叉互补修复基因1（X-ray repair cross-complementing group1,XRCC1）的399位点（Arg399Gln）多态性与结直肠癌（CRC）易感性的关系。[方法]检索中国生物医学数据库（CBM）、PubMed、Springer等数据库,获取有关XRCC1Arg399Gln多态性同结直肠癌易感性关系的病例对照研究并进行Meta分析,以病例组及对照组XRCC1Arg399Gln等位基因分布的比值比（OR）为效应指标,应用Meta分析软件Review Manager（version5.0.10）对各研究原始数据进行统计处理及异质性检验,计算合并OR值及其95%可信区间（95%CI）。[结果]纳入11项病例对照研究,共2287例结直肠癌患者和3485例对照,Meta分析结果显示,Gln/Gln vs.Arg/Arg OR=1.12,95%CI为0.76～1.65,Z=0.58,POR=0.56;Gln/Gln＋Arg/Gln vs.Arg/Arg OR=1.11,95%CI为0.85～1.44,Z=0.78,POR=0.43;Gln/Glnvs.Arg/Arg＋Arg/Gln OR=1.07,95%CI为0.79～1.46,Z=0.43,POR=0.67;Arg/Gln vs.Arg/Arg OR=1.14,95%CI为0.88～1.48,Z=1.02,POR=0.31。[结论]XRCC1Arg399Gln多态性与结直肠癌易感性之间无显著相关性。     

Distribution and Haplotype Associations of XPD Lys751Gln,XRCC1 Arg280His and XRCC1 Arg399Gln Polymorphisms with Nasopharyngeal Carcinoma in the Malaysian Population

Background: DNA repair pathways play a crucial role in maintaining the human genome. Previous studiesassociated DNA repair gene polymorphisms (XPD Lys751Gln, XRCC1 Arg280His and XRCC1 Arg399Gln)with nasopharyngeal carcinoma. These non-synonymous polymorphisms may alter DNA repair capacity andthus increase or decrease susceptibility. The present study aimed to determine the genotype distribution of XPDcodon 751, XRCC1 codon 280 and codon 399 polymorphisms and haplotype associations among NPC cases andcontrols in the Malaysian population. Materials and Methods: We selected 157 NPC cases and 136 controls fromtwo hospitals in Kuala Lumpur, Malaysia for this study. The polymorphisms studied were genotyped by PCRRFLPassay and allele and genotype frequencies, haplotype and linkage disequilibrium were determined usingSNPstat software. Results: For the XPD Lys751Gln polymorphism, the frequency of the Lys allele was higher incases than in controls (94.5% versus 85.0%). For the XRCC1 Arg280His polymorphism, the frequency of Argallele was 90.0% and 89.0% in cases and controls, respectively and for XRCC1 Arg399Gln the frequency of theArg allele was 72.0% and 72.8% in cases and controls respectively. All three polymorphisms were in linkagedisequilibrium. The odds ratio from haplotype analysis for these three polymorphisms and their associationwith NPC was 1.93 (95%CI: 0.90-4.16) for haplotype CGC vs AGC allele combinations. The global haplotypteassociation with NPC gave a p-value of 0.054. Conclusions: Our study provides an estimate of allele and genotypefrequencies of XRCC1Arg280His, XRCC1 Arg399Gln and XPD Lys751Gln polymorphisms in the Malaysianpopulation and showed no association with nasopharyngeal cancer.     

Polymorphisms of DNA repair genes XRCC1 and XPD and their associations with risk of esophageal squamous cell carcinoma in a Chinese population

Esophageal squamous cell carcinoma (ESCC), which is prevalent in China, is believed to be induced by environmental carcinogens. Accumulating evidence has shown that individual variation in DNA repair capacity resulting from genetic polymorphism influences risk of environmental carcinogenesis. We therefore investigated the associations between genetic polymorphisms in the DNA repair genes XRCC1 (Arg194Trp and Arg399Gln) and XPD (Asp312Asn and Lys751Gln) and risk of ESCC in an at-risk Chinese population. Genotypes were determined by a PCR-based approach in 433 patients with ESCC and 524 frequency-matched normal controls. We found that individuals with Trp/Trp genotype at XRCC1 Arg194Trp site had a 2-fold increased risk of this disease compared to Arg/Arg genotype (adjusted OR = 1.98; 95% CI 1.26-3.12). Furthermore, when compared to Arg/Arg and Arg/Trp genotype combined, homozygote for Trp/Trp genotype significantly increased the risk of developing ESCC, with the adjusted OR being 2.07 (95% CI 1.34-3.20). However, the XRCC1 Arg399Gln polymorphism was not significantly associated with risk of ESCC, with the adjusted OR being 0.87 (95% CI 0.55-1.37). Neither Asp312Asn nor Lys751Gln polymorphisms in the XPD gene influenced risk of ESCC in our study. These findings suggest that DNA repair gene XRCC1 but not XPD might play a role in esophageal carcinogenesis and might represent a genetic determinant in the development of the cancer.     

Association of XPD and XRCC1 Genetic Polymorphisms with Hepatocellular Carcinoma Risk

Aim: XRCC1 and XPD are two major repair genes involved in nucleotide excision repair (NER), whichis reported to be associated with risk of several cancers. We explored the association of XRCC1 and XPDpolymorphisms with the risk of HCC. Methods: A total of 410 cases with HCC and 410 health controls werecollected. XRCC1 Arg194Trp, XRCC1 Arg399Gln, XPD Lys751Gln and XPD Asp312Asn genotyping wasperformed by duplex polymerase-chain-reaction with the confronting-two-pair primer (PCR-CTPP) method.Results: XRCC1 194Trp/Trp was strongly significantly associated with an increased risk of HCC cancer whencompared with the wide-type genotype (OR=2.26, 95% CI=(1.23-5.38). Individuals carrying the XRCC1 399Gln/Gln showed increased risk of HCC (OR=1.74, 95%CI=1.06-2.74). The XPD 751Gln/Gln and Gln allele genotypewere associated with strong elevated susceptibility to HCC (OR=3.51 and 1.42, respectively). Conclusion: Theseresults suggest that polymorphisms in XRCC1 and XPD may have functional significance in risk of HCC.     

MS-920: DNA repair gene polymorphisms, diet and colorectal cancer risk in Taiwan

This hospital-based case-control study examined whether polymorphic DNA repair genes: XRCC1 Arg399Gln, XRCC3 Thr241Met and XPD Lys751Gln, play a role in the susceptibility to colorectal cancer. We genotyped these polymorphisms for 727 newly diagnosed colorectal adenocarcinoma cases and 736 age and sex matched healthy controls in Taiwan. Although the colorectal cancer risk was not significantly associated with these genes, the risk was significantly elevated in younger subjects (< or =60 years) with the XRCC1 399Arg/Arg genotype compared to those with XRCC1 399Gln allele (OR=1.46, 95% CI=1.06-2.99, P=0.02). The stratified analysis showed that XRCC3 interacted with meat consumption (P for interaction=0.02), but was limited to the low meat consumption (OR=2.34, 95% CI=1.28-4.29). Our results suggest that the XRCC1 Arg399Gln polymorphism may contribute to the risk of early-onset colorectal cancer and the XRCC3 Thr241Met polymorphism may modify the risk for meat-associated colorectal cancer.     

Association Between Polymorphisms of XRCC1 Arg399Gln and XPD Lys751Gln Genes and Prognosis of Colorectal Cancer in a Chinese Population

We conducted this study to detect associations between XRCC1 Arg399Gln and XPD Lys751Gln genotypesand survival of colorectal cancer patients treated with 5-FU/oxalipatin chemotherapy. We included 289 Chinesepatients with advanced colorectal cancer, who had received 5-FU/oxalipatin chemotherapy as first-line treatmentfrom January 2005 to January 2007. All patients were followed up till Nov. 2011. Genotyping for XRCC1Arg399Gln and XPD Lys751Gln polymorphisms was based upon duplex polymerase-chain-reaction with thePCR-RFLP method. In our study, we found the XRCC1 399 Gln/Gln genotype to confer significantly higherrates of response to chemotherapy when compared to the Arg/Arg genotype [OR (95% CI)= 2.56(1.57-2.55)].patients with the XPD 751 Gln/Gln genotype had significantly higher rates of response to chemotherapy [OR(95% CI)= 1.54(0.87-2.65)] and those with the XRCC1 399 Gln/Gln genotype had a longer average survivaltime and significantly lower risk of death than did those with the Arg/Arg genotype [HR (95% CI)= 0.66(0.36-0.95)]. Similarly, those carrying the XPD 751Gln/Gln genotype had 0.51-fold the risk of death of those with XPD751Lys/Lys [HR (95% CI)= 0.51(0.33 -0.94)]. In conclusion, it is suggested that the XRCC1 Arg399Gln and XPDLys751Gln polymorphisms should be routinely assessed to determine colorectal patients who are more likely tobenefit from 5-FU/oxalipatin chemotherapy.     

No association between hOGG1, XRCC1, and XPD polymorphisms and risk of reflux esophagitis, Barrett's esophagus, or esophageal adenocarcinoma: results from the factors influencing the Barrett's adenocarcinoma relationship case-control study.

Reflux of gastric contents can lead to development of reflux esophagitis and Barrett's esophagus. Barrett's esophagus is a risk factor for esophageal adenocarcinoma. Damage to DNA may lead to carcinogenesis but is repaired through activation of pathways involving polymorphic enzymes, including human 8-oxoguanine glycosylase 1 (hOGG1), X-ray repair cross-complementing 1 (XRCC1), and xeroderma pigmentosum group D (XPD). Of the single nucleotide polymorphisms identified in these genes, hOGG1 Ser 326 Cys, XRCC1 Arg 399 Gln, and XPD Lys 751 Gln are particularly common in Caucasians and have been associated with lower DNA repair capacity. Small studies have reported associations with XPD Lys 751 Gln and esophageal adenocarcinoma. XRCC1 Arg 399 Gln has been linked to Barrett's esophagus and reflux esophagitis. In a population-based case-control study, we examined associations of the hOGG1 Ser 326 Cys, XRCC1 Arg 399 Gln, and XPD Lys 751 Gln polymorphisms with risk of esophageal adenocarcinoma, Barrett's esophagus, and reflux esophagitis. Genomic DNA was extracted from blood samples collected from cases of esophageal adenocarcinoma (n = 210), Barrett's esophagus (n = 212), reflux esophagitis (n = 230), and normal population controls frequency matched for age and sex (n = 248). Polymorphisms were genotyped using TaqMan allelic discrimination assays. Odds ratios and 95% confidence intervals were obtained from logistic regression models adjusted for potential confounding factors. There were no statistically significant associations between these polymorphisms and risk of esophageal adenocarcinoma, Barrett's esophagus, or reflux esophagitis.     

XRCC1 and XPD polymorphisms and esophageal adenocarcinoma risk

DNA damage is important in the pathogenesis of esophageal adenocarcinoma (EA). Polymorphic variants in DNA repair genes may be modifiers of the risk of EA through their role in altering human host response to gastroesophageal acid reflux, a well-described risk factor for EA. We studied the role of genetic polymorphisms of two key DNA repair genes, xeroderma pigmentosum group D (XPD) (Asp312Asn and Lys751Gln) in the nucleotide excision repair (NER) pathway and X-ray repair cross-complementing gene 1 (XRCC1) (Arg399Gln) in the base excision repair (BER) pathway, in the development of EA in 183 cases and 336 frequency-matched controls for age, gender and race. Genomic DNA was extracted from blood samples. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained from logistic regression models, adjusted for body mass index at 18 years of age, smoking and alcohol exposure. The variant genotypes of XPD Lys751Gln polymorphism were associated with a higher risk of EA; the adjusted OR comparing Gln/Gln + Lys/Gln with Lys/Lys was 1.49 (95% CI: 1.02-2.14). Although no significant relationships were found for the XRCC1 Arg399Gln polymorphism alone, this polymorphism did modify the relationship between XPD Lys751Gln and EA risk; when both polymorphisms were evaluated together, adding the number of variant alleles of the two polymorphisms resulted in a significant trend (trend test, P = 0.008); compared with individuals with no variant alleles (n = 88), the adjusted ORs of developing EA are 1.49 (95% CI: 0.88-2.59), 1.69 (95% CI: 0.98-2.96) and 2.58 (95% CI: 1.31-5.06) for one (n = 195), two (n = 166) and three or four variant alleles (n = 70), respectively. No relationships were found for the XPD Asp312Asn polymorphism. We conclude that combined NER and BER pathways are important to the development of EA.     

The XPD 751Gln allele is associated with an increased risk for esophageal adenocarcinoma: a population-based case-control study in Sweden

Mechanisms behind the strong associations of esophageal adenocarcinoma risk with gastroesophageal reflux (GOR) and body mass remain to be defined. In a nationwide population-based case-control study, we examined associations of polymorphisms in the DNA repair genes XPD, XPC, XRCC1 and XRCC3 with risk of esophageal adenocarcinoma, squamous-cell carcinoma (SCC) and gastric cardia adenocarcinoma, and paid special attention to possible interactions with symptomatic reflux or body mass. We collected blood samples from 96, 81 and 126 interviewed incident cases of esophageal adenocarcinoma, esophageal SCC and gastric cardia adenocarcinoma, respectively, and 472 randomly selected controls, frequency-matched with regard to age and sex. DNA was extracted and polymorphisms in XPD codon 751 (Lys-->Gln), codon 312 (Asp-->Asn), C insertion in intron 10 of XPD, XPC codon 939 (Lys-->Gln), XRCC1 codon 399 (Arg-->Gln) and XRCC3 codon 241 (Thr-->Met) were examined using PCR-RFLP. Odds ratios (ORs) derived from multivariate logistic regression with adjustments for potential confounding factors estimated relative risks. XPD codon 751 Lys/Gln and Gln/Gln genotypes, compared with Lys/Lys genotype, were both associated with a more than doubled risk for esophageal adenocarcinoma (OR=2.4; 95% CI=1.4-4.4; OR=2.7, 95% CI=1.3-5.9). The combined effects of these genotypes and symptomatic GOR or body mass showed borderline significant deviation from additivity. Excess risks for esophageal SCC were also noted for XPD 751Gln variant genotypes. Other studied variants were not found to be related to the three tumors. Our study suggests that XPD 751Gln allele is a potential genetic marker for susceptibility to esophageal adenocarcinoma.     

Polymorphisms of DNA repair genes and risk of non-small cell lung cancer

Lung cancer is a leading cause of cancer mortality with an inter-individual difference in susceptibility to the disease. The inheritance of low-efficiency genotypes involved in DNA repair and replication may contribute to the difference in susceptibility. We investigated 44 single nucleotide polymorphisms (SNPs) in 20 DNA repair genes including nucleotide excision repair (NER) genes XPA, ERCC1, ERCC2/XPD, ERCC4/XPF and ERCC5/XPG; base excision repair (BER) genes APE1/APEX, OGG1, MPG, XRCC1, PCNA, POLB, POLiota, LIG3 and EXO1; double-strand break repair (DSB-R) genes XRCC2, XRCC3, XRCC9, NBS1 and ATR; and direct damage reversal (DR) gene MGMT/AGT. The study included 343 non-small cell lung cancer (NSCLC) cases and 413 controls from Norwegian general population. Our results indicate that SNPs in the NER genes ERCC1 (Asn118Asn, 15310G>C, 8902G>T), XPA (-4G>A), ERCC2/XPD (Lys751Gln) and ERCC5/XPD (His46His); the BER genes APE1/APEX (Ile64Val), OGG1 (Ser326Cys), PCNA (1876A>G) and XRCC1 (Arg194Trp, Arg280His, Arg399Gln); and the DSB-R genes ATR (Thr211Met), NBS1 (Glu185Gln), XRCC2 (Arg188His) and XRCC9 (Thr297Ile) modulate NSCLC risk. The level of polycyclic aromatic hydrocarbon-DNA (PAH-DNA) adducts in normal lung tissue from 211 patients was analysed. The variant alleles of XRCC1(Arg280His), XRCC1 (Arg399Gln), ERCC1(G8092T), ERCC5(His46His) and MGMT/AGT(Lys178Arg) were more frequent in patients with PAH-DNA adduct levels lower than the mean whereas the XRCC1(Arg194Trp) variant was more frequent in cases with higher adduct levels than the mean.     

Interaction of XRCC1 and XPD Gene Polymorphisms with Lifestyle and Environmental Factors Regarding Susceptibility to Lung Cancer in a High Incidence Population in North East India

Background: This study aimed to explore the role of XRCC1 (Arg399Gln) and XPD (Lys751Gln) genepolymorphisms, lifestyle and environmental factors as well as their possible interactions in propensity to developlung cancer in a population with high incidence from North East India. Materials and Methods: A total of 272lung cancer cases and 544 controls were collected and XRCC1 (Arg399Gln) and XPD (Lys751Gln) genotypes wereanalyzed using a polymerase chain reaction based restriction fragment length polymorphism assay. Conditionalmultiple logistic regression analysis was used to calculate adjusted odds ratios and 95% confidence intervalsafter adjusting for confounding factors. Results: The combined Gln/Gln genotype of XRCC1 and XPD genes(OR=2.78, CI=1.05-7.38; p=0.040) was significantly associated with increased risk for lung cancer. Interactionof XRCC1Gln/Gln genotype with exposure of wood combustion (OR=2.56, CI=1.16-5.66; p=0.020), exposure ofcooking oil fumes (OR=3.45, CI=1.39-8.58; p=0.008) and tobacco smoking (OR=2.54, CI=1.21-5.32; p=0.014) andinteraction of XPD with betel quid chewing (OR=2.31, CI=1.23-4.32; p=0.009) and tobacco smoking (OR=2.13,CI=1.12-4.05; p=0.022) were found to be significantly associated with increased risk for lung cancer. Conclusions:Gln/Gln alleles of both XRCC1 and XPD genes appear to amplify the effects of household exposure, smokingand betel quid chewing on lung cancer risk in the study population.