DNA repair gene XRCC1 polymorphisms and susceptibility to childhood acute lymphoblastic leukemia: a meta-analysis

Objective： To estimate the relationship between genetic polymorphisms of X-ray repair cross- complementing group 1 （XRCC1） and the susceptibility to childhood acute lymphoblastic leukemia （ALL）. Methods： Relevant case-control studies were enrolled in the meta-analysis. We applied Rev Man 4.2 software to pool raw data and test studies＇ heterogeneity and to calculate the incorporated odds ratio （OR） and 95% confidence interval （95% CI）. Results： Our data showed that the OR for the Gln allele of the Arg399Gln polymorphism, compared with the Arg allele, was 1.35 （95% CI, 1.16-1.57; P〈0.0001） for childhood ALL patients. Similarly, the homozygous genotype Gln/Gln and heterozygous genotype Arg/Gln both significantly increased the risk of childhood ALL compared with the wild genotype Arg/Arg （OR =1.58; 95% CI, 1.13-2.21; P=0.008; OR =1.51; 95% CI, 1.21-1.87; P=0.0002）. The dominant model of Arg399Gln was associated with childhood ALL risk （OR =1.54; 95% CI, 1.25-1.89; P〈0.0001）. The ethnic subgroup analysis demonstrated that the Gln allele in all five ethnic groups was prone to be a risk factor for childhood ALL just with different degrees of correlation while Arg194Trp SNP showed a protective or risk factor or irrelevant thing in different races. Conclusions： XRCC1 399 polymorphism may increase the risk of childhood ALL. Different ethnic groups with some gene polymorphism have different disease risks.

XRCC1基因多态性与宫颈鳞癌放疗敏感性的关系

目的探讨XRCC1基因Arg194Trp、Arg399Gln单核苷酸多态性(SNP)与外生型宫颈鳞状细胞癌放疗敏感性的关系。方法选择经组织病理学确诊的外生型宫颈鳞状细胞癌患者73例。其中临床分期Ⅰ期4例,Ⅱ期36例,Ⅲ期30例,Ⅳ期3例。肿瘤直径≤4 cm 30例,肿瘤直径>4 cm 43例;A点剂量≤80 Gy者36例,A点剂量>80 Gy者37例。近期疗效为完全缓解者(CR组)47例,部分缓解者(PR组)26例。采用错配扩增聚合酶链式反应检测患者血液标本的XRCC1 Arg194Trp、Arg399Gln SNP的基因型频率分布,分析其与宫颈癌放疗敏感性的关系。结果 XRCC1基因Arg194Trp分型中,携带Arg/Arg、Arg/Trp、TrP/Trp分别有31例(42.5%)、37例(50.7%)、5例(6.8%);Arg399Gln分型中,携带Arg/Arg、Arg/Gln、Gln/Gln分别有26例(35.6%)、39例(53.4%)、8例(11.0%)。CR组与PR组Arg194Trp、Arg399Gln基因型分布差异均无统计学意义。影响放疗敏感性的多因素Logistic回归分析结果显示,临床分期晚为PR的危险因素。结论 XRCC1基因Arg194TrpSNP、Arg399Gln SNP与外生型宫颈鳞状细胞癌放疗敏感性无相关性。临床分期越晚放疗敏感性越差。

XRCC1 Polymorphisms and Pancreatic Cancer:A Meta-Analysis

Objective：To assess the association between X-ray repair cross-complementating group 1 （XRCC1） polymorphisms and pancreatic cancer.Methods：We searched MEDLINE,Web of Science and HuGE Navigator at June 2010,and then quantitatively summarized associations of the XRCC1 polymorphisms with pancreatic cancer risk using meta-analysis.Results：Four studies with 1343 cases and 2302 controls were included.Our analysis found：at codon 194,the Trp allele did not decrease pancreatic cancer risk （Arg/Arg versus Trp/Trp：OR=0.97;95% CI：0.48-1.96;P=0.97;Arg/Arg versus Arg/Trp：OR=0.89;95% CI：0.70-1.13;P=0.55;Arg/Trp versus Trp/Trp：OR=1.06;95% CI：0.52-2.16;P=0.90）;at codon 280,only a study showed a nonsignificant association between single nucleotide polymorphism with pancreatic cancer risk;at codon 399,the Gln allele also showed no signi？cant effect on pancreatic cancer compared to Arg allele （Arg/Arg versus Gln/Gln：OR=0.94;95% CI：0.74-1.18;Arg/Arg versus Arg/Gln：OR=0.97;95% CI：0.83-1.13;Arg/Gln versus Gln/Gln：OR=0.97;95% CI：0.77-1.22）.The shape of the funnel plot and the Egger＇s test did not detect any publication bias.Conclusion：There is no evidence that XRCC1 polymorphisms （Arg194Trp,Arg280His,and Arg399Gln） are associated with pancreatic cancer risk.