Polymorphisms of DNA repair genes XRCC1 and XRCC3, interaction with environmental exposure and risk of chronic gastritis and gastric cancer

AIM: To evaluate the association between polymorphisms XRCC1 Arg194Trp and Arg399Gln and XRCC3 Thr241Met and the risk for chronic gastritis and gastric cancer, in a Southeastern Brazilian population. METHODS: Genotyping by PCR-RFLP was carried out on 202 patients with chronic gastritis (CG) and 160 patients with gastric cancer (GC), matched to 202 (CI) and 150 (C2) controls, respectively. RESULTS: No differences were observed among the studied groups with regard to the genotype distribution of XRCCl codons 194 and 399 and of XRCC3 codon 241. However, the combined analyses of the three variant alleles (194Trp, 399Gln and 241Met) showed an increased risk for chronic gastritis when compared to the GC group. Moreover, an interaction between the polymorphic alleles and demographic and environmental factors was observed in the CG and GC groups. XRCC1 194Trp was associated with smoking in the CG group, while the variant alleles XRCC1 399Gln and XRCC3 241Met were related with gender, smoking, drinking and H pylori infection in the CG and GC groups. CONCLUSION: Our results showed no evidence of a rela-tionship between the polymorphisms XRCCl Argl94Trp and Arg399Gln and XRCC3 Thr241Met and the risk of chronic gastritis and gastric cancer in the Brazilian population, but the combined effect of these variants may interact to increase the risk for chronic gastritis, considered a premalignant lesion. Our data also indicate a gene-environment interaction in the susceptibility to chronic gastritis and gastric cancer.     

XPC Lys939Gln polymorphism,smoking and risk of sporadic colorectal cancer among Malaysians

AIM: To investigate the risk association of xeroderma pigmentosum group C (XPC ) Lys939Gln polymorphism alone and in combination with cigarette smoking on colorectal cancer (CRC) predisposition. METHODS: Peripheral blood samples of 510 study subjects (255 CRC patients, 255 controls)were collected. DNA was extracted and genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism. The association between polymorphic genotype and CRC predisposition was determined using the OR and 95%CI. RESULTS: The frequency of the homozygous variant (Gln/Gln) genotype was significantly higher in cases compared with controls (16.0% vs 10.2%, P = 0.049). The Gln/Gln genotype of XPC showed a significantly higher association with the risk of CRC (OR = 1.884; 95%CI: 1.082-3.277; P = 0.025). In the case of allele frequencies, variant allele C was associated with a significantly increased risk of CRC (OR = 1.375; 95%CI: 1.050-1.802; P = 0.020). Moreover, the risk was markedly higher for those who were carriers of the Gln/Gln variant genotype and were also cigarette smokers (OR = 3.409; 95%CI: 1.061-10.949; P = 0.032). CONCLUSION: The XPC Gln/Gln genotype alone and in combination with smoking increases the risk of CRC among Malaysians.     

DNA修复基因XRCC1 Arg194Trp Arg280His和Arg399Gln多态性与前列腺癌相关性的Meta分析

目的探讨DNA修复基因X线修复交叉互补因子1（XRCC1）主要单核苷酸多态性与前列腺癌易感性的关系。方法在MEDLINE、EMBASE和OVID数据库上检索文献,收集及提取符合纳入标准的以XRCC1密码子194、280、399多态性与前列腺癌易感性为内容的病例对照研究文献,应用Stata统计软件进行Meta分析,比值比（ORs）及其95%可信区间（95%CI）评价关联强度;应用SPSS软件分析吸烟与前列腺癌关系,OR？评价其相对危险度。结果 XRCC1 399 Gln/Gln和XRCC1 280 Arg/His与前列腺癌的发病风险有关（Gln/Gln vs Arg/Arg：OR？=1.27,95%CI=1.02～1.59;Arg/His vs Arg/Arg：OR？=1.66,95%CI=1.09～2.52）,尤其在亚组分析中亚洲人的Gln/Gln明显增加了前列腺癌的发病风险（OR？=1.52,95%CI=1.18～1.96）;Arg194Trp与前列腺癌的发病风险无明显关联。吸烟是前列腺癌的危险因素（χ2=13.974,P=0.000,OR？=1.22）。结论 XRCC1 399 Gln/Gln和280 Arg/His可能与前列腺癌的易感性相关。     

Association between polymorphisms of APE1 and OGG1 and risk of colorectal cancer in Taiwan

AIM: To evaluate the effects of OGG1(Ser326Cys, 11657A/G, and Arg154His) and APE1(Asp148Glu, and T-656G) polymorphisms on colorectal cancer(CRC) risk.METHODS: We enrolled 727 cases newly diagnosed with colorectal adenocarcinoma and 736 age- and sex-matched healthy controls from a medical center in Taiwan. Genomic DNA isolated from the buffy coat was used for genotyping through polymerase chain reaction. Unconditional logistic regressions were used for calculating ORs and 95%CIs to determine the association between the genetic polymorphisms and CRC risk. Haplotype frequencies were estimated using PHASE software. Moreover, stratification analyses onthe basis of sex, age at diagnosis, and tumor subsite and stage were performed.RESULTS: The CRC risk was higher in patients with the OGG1 326Ser/Cys + Cys/Cys genotype(OR = 1.38, 95%CI: 1.03-1.85, P = 0.030), particularly high in patients with stage Ⅲ + Ⅳ cancer(OR = 1.48, 95%CI: 1.03-2.13) compared with patients with the Ser/Ser genotype. In addition, OGG1 11657 G allele carriers had a 41% reduced CRC risk among stage 0-Ⅱ patients(OR = 0.59, 95%CI: 0.35-0.98). The CRC risk was significantly higher among females with the APE1 Glu allele(OR = 1.41, 95%CI: 1.02-1.96). The APE1 148Glu/-656 G haplotype was also associated with a significant CRC risk in females(OR = 1.36, 95%CI: 1.03-1.78).CONCLUSION: OGG1 and APE1 polymorphisms are associated with stage- and sex-specific risk of CRC in the Taiwanese population.     

Association between pepsinogen C gene polymorphism and genetic predisposition to gastric cancer

AIM: To identify a molecular marker for gastric cancer, andto investigate the relationship between the polymorphismof pepsinogen C (PGC) gene and the genetic predispositionto gastric cancer.METHODS: A total of 289 cases were involved in this study.115 cases came from Shenyang area, a low risk area ofgastric cancer, including 42 unrelated controls and 73 patientswith gastric cancer. 174 cases came from Zhuanghe area, ahigh-risk area of gastric cancer, including 113 unrelatedcontrols, and 61 cases from gastric cancer kindred families.The polymorphism of PGC gene was detected by polymerasechain reaction (PCR) and the relation between the geneticpolymorphism of PGC and gastric cancer was examined.RESULTS: Four alleles, 310bp (allele 1), 400bp (allele 2),450bp (allele 3), and 480bp (allele 4) were detected byPCR. The frequency of allele 1 was higher in patients withgastric cancer than that in controls. Genotypes containinghomogenous allele 1 were significantly more frequent inpatients with gastric cancerthan that in controls (0.33, 0.14,x2＝3.86, P＜0.05). There was no significant differencebetween the control group of Zhuanghe and the group ofgastric cancer kindred. But the frequency of allele 1 washigher in control group of Zhuanghe area than that in controlgroup of Shenyang area and genotypes containinghomogenous allele 1 were significantly more frequent inthe control group of Zhuanghe area than those in controlgroup of Shenyang area (0.33, 0.14, x2＝4.32, P＜0.05). Inthe group of gastric cancer kindred the frequency of allele 1was significantly higher than that in control group ofShenyang area (0.5164, 0.3571, x2＝4.47, P＜0.05).Genotypes containing homogenous allele 1 were significantlymore frequent in the group of gastric cancer kindred thanthose in control group of Shenyang area (0.36, 0.14, x2＝4.91,P＜0.05).CONCLUSION: These results suggest that there is somerelation between pepsinogen C gene polymorphism andgastric cancer, and the person with homogenous allele 1predisposes to gastric cancer than those with othergenotypes. Pepsinogen C gene polymorphism may be usedas a genetic marker for a genetic predisposition to gastriccancer. The distribution of pepsinogen C gene polymorphismin Zhuanghe, a high-risk area of gastric cancer, is differentfrom that in Shenyang, a low risk area of gastric cancer.     

Matrix metalloproteinase-9-1562C〉T polymorphism may increase the risk of lymphatic metastasis of colorectal cancer

AIM: To explore the role of the matrix metalloproteinase-9 (MMP-9) polymorphism in colorectal cancer (CRC) in a northeast Chinese population. METHODS: Genotyping of MMP-9 -1562C>T and 279R>Q polymorphisms was carried out on blood samples from 137 colorectal cancer patients and 199 controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Multivariate logistic regression models were used to calculate adjusted odds ratios (OR) and 95% confidence intervals (95% CI). RESULTS: The distribution of MMP-9 -1562C>T and 279 R>Q genotype was not significantly associated with the risk of CRC. However, the risk of llymph node metastasis of CRC was increased in patients with the -1562T allele (OR = 2.601; 95% CI = 1.160-5.835; P = 0.022). The frequency of MMP-9 279RR RQ genotype was higher than the QQ genotype among CRC patients younger than sixty years old (OR = 0.102; 95% CI = 0.013-0.812; P = 0.012). CONCLUSION: Our results indicated that the MMP-9-1562C>T polymorphism affects lymph node metastasis of CRC. In addition, the MMP-9 279R allele may lead to a younger age of onset of colorectal cancer.     

中国人群XRCC1 Arg399Gln基因多态性与肝癌易感性Meta分析

目的:系统评价中国人群X线修复交叉互补基因1(X-ray repair cross complementing group 1,XRCC1)Arg399Gln基因多态性与肝癌易感性的关系.方法:在Pub Med、MEDLINE、EMBASE、CNKI、CBM、VIP及万方数据库中检索2000-01-01/2015-01-10发表的所有有关中国人群XRCC1 Arg399Gln基因多态性与肝癌易感性关系的相关文献.按照纳入和排除标准独立选择文献、提取资料,采用Stata12.0软件进行Meta分析,计算合并比值比(odds ratio,OR)及其95%可信区间(95%confidence interval,95%CI),并进行敏感性分析和发表偏倚的估计.结果:按照入选标准,共纳入13个研究,包括2972例患者和3789例对照者.Meta分析结果显示,与基因型Arg/Arg、Arg/Arg+Arg/Gln分别进行比较,基因型Gln/Gln均增加中国人群罹患肝癌风险(OR=1.47,95%CI:1.24-1.74,P0.001;O R=1.26,95%C I:1.08-1.48,P=0.003);与基因型Arg/Arg进行比较,基因型Gln/Gln+Arg/Gln增加中国人群罹患肝癌风险(OR=1.49,95%CI:1.21-1.83,P0.001).与等位基因Argalele比较,等位基因Gln-allele增加中国人群罹患肝癌的风险(OR=1.33,95%CI:1.16-1.54P0.001).结论:XRCC1 Arg399Gln基因多态性与中国人群肝癌易感性相关,基因型Gln/Gln增加中国人群罹患肝癌的风险.     

X线交错互补修复基因1多态性与前列腺癌的遗传易感性

选择华东地区207例前列腺癌（PCa）患者为作为病例组,235例非肿瘤、非前列腺疾病的男性患者作为对照组。用PCR-RFLP方法分析两组X线交错互补修复基因1（XRCC1）Arg194Trp和Arg280His两个位点的多态性,比较不同基因型与PCa易感性的关系。结果显示,XRCC1第194密码子携带194Trp等位基因的个体（Arg/Trp＋Trp/Trp）患PCa的风险较Arg/Arg基因型的个体降低38%（校正OR=0.62,95%CI为0.410.93）;在≤70岁及不吸烟两组人群中,携带194Trp等位基因的个体PCa发病风险比Arg/Arg基因型的个体分别降低45%（OR=0.55,95%CI为0.30-1.00）和52%（校正OR=0.48,95%CI为0.24-0.95）。认为XRCC1 Arg194Trp位点多态性可能对PCa遗传易感性产生影响,并与吸烟在PCa的发病中有一定的协同作用。     

XRCC1 genetic polymorphism Arg399GIn and gastric cancer risk： A meta-analysis

AIM： To evaluate the association between X-ray crosscomplementing gene 1 （XRCCl） genetic polymorphism Arg399Gln and gastric cancer risk by means of metaanalysis. METHODS： We searched PubMed and NCBI up to June 1, 2008. A total of 16 clinical trials and reports were identified, but only 8 trials qualified under our selection criteria. Statistical analysis was performed with the software program Review Manage, version 4.2.8. RESULTS： Of the 8 case-control studies selected for this meta-analysis, a total of 1334 gastric cancer cases and 2194 controls were included. For Arg399GIn, the Gin/Gin genotype carriers did not have a decreased cancer risk compared with those individuals with the Arg/Arg genotype （OR = 0.92, 95% CI, 0.71-1.19; P = 0.51）. Similarly, no associations were found in the recessive and dominant modeling （Gin/Gin vs Arg/GIn ＋ Arg/Arg： OR = 0.96; 95% CI, 0.77-1.19; P = 0.70 and Gin/Gin ＋ Arg/GIn vs Arg/Arg： OR = 0.90, 95% CI, 0.77-1.05; P = 0.18）. CONCLUSION： No association is found between the XRCC1 polymorphism Arg399GIn and gastric cancer risk.     

Relationship between genetic polymorphisms of metabolizing enzymes CYP2E1, GSTM1 and Kazakh＇s esophageal squamous cell cancer in Xinjiang, China

AIM: To analyze the relationship between genetic polymorphisms of metabolizing enzymes CYP2E1, GSTM1 and Kazakh's esophageal squamous cell cancer in China. METHODS: The genotypes of cytochromes P450 (CYP) 2E1 and glutathione S-transferase (GST) M1 were investigated by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) following PCR in 104 Kazakh's patients with esophageal cancer (EC) and 104 non-cancer controls. RESULTS: The frequency of CYP2E1 c1/c1 genotype was significantly higher in patients with cancer (77.9%) than in control subjects (24.0%) (P<0.05; OR, 11.13; 95%CI, 5.84-21.22). The difference of GSTM1 null was significantly more frequent in the cancer (34.6%) vs the control group (3.8%) (P<0.05; OR, 13.24; 95%CI, 4.50-38.89). On the other hand, the combination of GSTM1 presence and CYP2E1 c1/c1 genotypes increased the risk for cancer (P<0.05; OR, 13.42; 95%CI, 6.29-28.3). CONCLUSION: The CYP2E1 c1/c1, GSTM1 deletion genotypes are genetically susceptible biomarkers for ESCC in Kazakh population. Individuals with allele c1 of RsaI polymorphic locus for CYP2E1 may increase the risk of ESCC. Moreover, CYP2E1 wild type (c1/c1) increased the susceptibility to ESCC risk in Kazakh individuals with GSTM1 presence genotype.     

A meta-analysis of XRCC1 single nucleotide polymorphism and susceptibility to gynecological malignancies

Background:Gynecological malignant tumor is a serious threat to women''s health, cervical cancer, endometrial cancer and ovarian cancer are the most common. The eponymous protein encoded by the XRCC1 (X-ray repair cross complementation 1) gene is an important functional protein in the process of single-stranded DNA damage. Non-synonymous mutations of XRCC1 gene cause amino acid sequence changes that affect protein function and DNA repair ability, and may affect the interaction with other DNA repair proteins, leading to increased risk of tumor development. Many studies have assessed the association between XRCC1 gene polymorphism and the risk of cancer in the female reproductive system, but the results have been inconclusive. In this study, the relationship between XRCC1 Arg399Gln, Arg194Trp, Arg280His single nucleotide polymorphisms and susceptibility to gynecological malignancies was further explored by meta-analysis.Methods:English database: Pubmed, Medline, Excerpta Medica Database, Cochrance, etc; Chinese database: China national knowledge infrastructure, Wanfang Database, etc. STATA14 was used for statistical analysis, such as odd ratio (OR) value, subgroup analysis, heterogeneity test, sensitivity analysis, and publication bias.Results:In gynecologic cancers, the allele frequency difference of Arg399Gln case control group was statistically significant (GvsA: P = .007). There was no significant difference in allele frequency in the Arg194Trp and Arg280His case control groups (P = .065, 0.198). In different gene models, Arg399Gln was significantly correlated with gynecologic cancers susceptibility (GGvs AA: OR 0.91; 95% confidence interval [CI], 0.85 0.98); Arg194Trp was significantly correlated with gynecologic cancers susceptibility (CCvs TT: OR 0.94; 95% CI 0.88,1.00; CCvs CT: OR 0.97; 95% CI 0.90, 1.05); Arg280His was significantly correlated with gynecologic cancers susceptibility (GGvs AA: OR 0.98; 95% CI 0.94, 1.02; GGvs GA: OR 1.00;95% CI 0.97, 1.04). In the subgroup analysis, Arg399Gln and Arg194Trp were significantly correlated with gynecologic cancers susceptibility in the Asian race (P = .000, 0.049). In the analysis of different cancer subgroups, Arg399Gln and cervical cancer susceptibility were statistically significant (P = .039). Arg194Trp and endometrial cancer susceptibility were statistically significant (P = .033, 0.001).Conclusions:XRCC1 Arg399Gln, Arg194Trp, Arg280His single nucleotide polymorphisms were associated with gynecologic cancer susceptibility. Arg399Gln genotype was statistically significant in relation to cervical cancer susceptibility. Arg194Trp genotype was statistically significant in relation to endometrial cancer susceptibility.     

Polymorphisms of XRCC1 gene and risk of gastric cardiac adenocarcinoma

X-ray repair cross complementing 1 (XRCC1) protein plays an important role in base excision repair. Single nucleotide polymorphisms (SNPs) in XRCC1 gene may affect DNA repairing ability and genetic susceptibility to cancer. This study was designed to investigate the correlation of XRCC1 Arg194Trp Arg280His and Arg399Gln SNPs with the risk of gastric cardiac adenocarcinoma (GCA). Genotypes were analyzed by polymerase chain reaction-restriction fragment length polymorphism assay in 455 patients with GCA and 650 age- and sex-matched controls. We did not find any significant difference in allele and genotype distributions of Arg194Trp Arg399Gln between the groups ( P  > 0.05). However, a significant increase in GCA risk was seen among smokers if they carried at least one XRCC1 280His ( Arg280His  +  His280His ) genotype (odds ratio = 1.59, 95% confidence interval = 1.01–2.51) compared with smokers not carrying these genotype. Our results indicated that XRCC1 Arg194Trp and Arg 399 Gln SNPs might not be associated with the risk of GCA. However, smokers with His allele at codon 280 had a significantly increased risk of GCA.     

XRCC1 Arg399Gln, Arg194Trp, and Arg280His Polymorphisms in Esophageal Cancer Risk: A Meta-Analysis

Background

The X-ray repair cross-complementation group 1 (XRCC1) protein plays an important role in base excision repair.

Aim

To elucidate the role of XRCC1 Arg399Gln, Arg194Trp and Arg280His genotypes in esophageal cancer risk, all available studies were considered in the present meta-analysis.

Methods

Eligible studies were identified by searching several electronic databases for relevant reports published before June 2012.

Results

According to the inclusion criteria and exclusion criteria, a total of 21 eligible studies were included in the pooled analyses. Among the 21 studies, 18 focused on Arg399Gln polymorphism, 11 described the Arg194Trp, and 4 articles investigated on Arg280His. Our analysis suggested that there was no evidence of significant association between XRCC1 Arg399Gln polymorphism and esophageal cancer risk in any genetic model. In the stratified analysis by ethnicity for Arg399Gln polymorphism and esophageal cancer, the results showed that Arg399Gln polymorphism was not associated with esophageal cancer risk. Only 4 studies analyzed the relationship between XRCC1 Arg280His polymorphism and the risk of esophageal cancer. The Arg/His and His/His genotypes were not significantly associated with increased risk of EC. A similar negative association was maintained in dominant and recessive models. However, for XRCC1 Arg194Trp polymorphism, our study showed individuals carrying the variant genotype Trp/Trp had a significant increased risk of esophageal cancer (OR = 1.295, 95 % CI 1.053–1.591, P = 0.014). In addition, increased associations were found in recessive model (OR = 1.332, 95 % CI 1.093–1.624, P = 0.005).

Conclusions

Our meta-analysis suggested that Arg194Trp Trp allele might act as a risk allele in its association with esophageal cancer.     

X-ray repair cross-complementing group 1 polymorphisms and hepatocellular carcinoma: a meta-analysis

AIM: To perform a systematic meta-analysis to investigate the association between X-ray repair cross-complementing group 1 (XRCC1) polymorphisms and hepatocellular carcinoma (HCC) risk.METHODS: Relevant studies extracted from PubMed, Embase, Wanfang, VIP and the Chinese National Knowledge Infrastructure databases up to March 2012 were included in the study. Stata software, version 11.0, was used for the statistical analysis. The odds ratios (ORs) and 95% confidence interval (CI) of the XRCC1 polymorphisms in HCC patients were analyzed and compared with healthy controls. The meta-analysis was performed using fixed-effect or random-effect methods, depending on the absence or presence of significant heterogeneity.RESULTS: Eleven studies with 2075 HCC cases and 2604 controls met our eligibility criteria (four studies, 888 cases and 938 controls for Arg194Trp, four studies, 858 cases and 880 controls for Arg280His, and nine studies, 1845 cases and 2401 controls for Arg399Gln). The meta-analysis revealed no associations between the Arg194Trp and Arg399Gln polymorphisms of the XRCC1 gene and HCC risk under all contrast models (codominant, dominant and recessive models) in the overall analysis and sensitivity analysis (the studies with controls not in the Hardy-Weinberg equilibrium were excluded). For XRCC1 Arg280His polymorphism, the overall analysis revealed the significant association between the His/His genotype and the increased risk of HCC (His/His vs Arg/Arg model, OR: 1.96, 95% CI: 1.03-3.75, P = 0.04). However, sensitivity analysis showed an altered pattern of result and non-significant association (OR: 2.06, 95% CI: 0.67-6.25, P = 0.20). The heterogeneity hypothesis test did not reveal any heterogeneity, and Begg’s and Egger’s tests did not find any obvious publication bias.CONCLUSION: The XRCC1 Arg194Trp and Arg399Gln polymorphisms are not associated with HCC risk. More rigorous association studies are needed to verify the involvement of XRCC1 Arg280His polymorphism in HCC susceptibility.     

APE1 polymorphisms are associated with colorectal cancer susceptibility in Chinese Hans

AIM: To study the association between four base excision repair gene polymorphisms and colorectal cancer risk in a Chinese population.METHODS: Two hundred forty-seven colorectal cancer (CRC) patients and three hundred cancer-free controls were enrolled in this study. Four polymorphisms (OGG1 Ser326Cys, APE1 Asp148Glu, -141T/G in the promoter region, and XRCC1 Arg399Gln) in components of the base excision repair pathway were determined in patient blood samples using polymerase chain reaction with confronting two-pair primers. The baseline information included age, gender, family history of cancer, and three behavioral factors [smoking status, alcohol consumption, and body mass index (BMI)]. χ² tests were used to assess the Hardy-Weinberg equilibrium, the distributions of baseline characteristics, and the four gene polymorphisms between the cases and controls. Multivariate logistic regression analyses were conducted to analyze the correlations between the four polymorphisms and CRC risk, adjusted by the baseline characteristics. Likelihood ratio tests were performed to analyze the gene-behavior interactions of smoking status, alcohol consumption, and BMI on polymorphisms and CRC susceptibility.RESULTS: The APE1 148 Glu/Glu genotype was significantly associated with an increased risk of colorectal cancer (OR = 2.411, 95%CI: 1.497-3.886, P < 0.001 relative to Asp/Asp genotype). There were no associations between OGG1, XRCC1, or APE1 promoter polymorphisms and CRC risk. A multivariate analysis including three behavioral factors showed that the APE1 148 Glu/Glu genotype was associated with an increased risk for CRC among both smokers and non-smokers, non-drinkers and individuals with a BMI ≥ 25 kg/m² (ORs = 2.356, 3.299, 2.654, and 2.581, respectively). The XRCC1 399 Arg/Gln genotype was associated with a decreased risk of CRC among smokers and drinkers (OR = 0.289, 95%CI: 0.152-0.548, P < 0.001, and OR = 0.327, 95%CI: 0.158-0.673, P < 0.05, respectively). The APE1 promoter polymorphism -141 T/G genotype was associated with a reduced risk of colorectal cancer among subjects with a BMI < 25 kg/m² (OR = 0.214, 95%CI: 0.069-0.660, P < 0.05 relative to T/T genotype). There were significant gene-behavior interactions between smoking status and XRCC1 Arg399Gln, as well as BMI and APE1 -141T/G polymorphism (all P < 0.05).CONCLUSION: APE1 Asp148Glu is associated with increased CRC risk and smoking alters the association between XRCC1 Arg399Gln and CRC risk in the Chinese Han population.     

Rheumatoid arthritis risk associates with DNA repair gene XRCC1 Arg399Gln polymorphism in Turkish patients

Rheumatoid arthritis (RA) is an autoinflammatory disease with a genetic background. The synoviocytes in RA shows cellular transformation with tumor-like features, and RA patients have genomic instability and relaxation of DNA repair mechanisms. The polymorphisms in BER repair pathway genes, XRCC1 and OGG1, may change the response to inflammation via altered DNA repair capacity. In this study, we aimed to investigate the relationship between the risk of RA and XRCC1 Arg194Trp, Arg399Gln, and OGG1 Ser326Cys polymorphisms in a group of Turkish RA patients. XRCC1 Arg194Trp, Arg399Gln, and OGG1 Ser326Cys polymorphisms were investigated by PCR–RFLP method in 100 RA patients and 158 healthy control subjects. The results were statistically analyzed by calculating the odds ratios (OR) and their 95% confidence intervals (95% CI) using the χ²-tests. RA patients in this study had significantly higher frequencies of XRCC1 Arg399Gln polymorphism in both homozygote (GG) (35%, OR: 7.78 [95% CI: 3.65–16.59], P < 0.001) and heterozygote (AG) forms (41%, OR: 2.17 [95% CI: 1.19–3.96], P < 0.01) and also increased frequency of 399Gln (G) allele (55%, OR:2.99 [95% CI: 1.67–5.37], P < 0.001). We conclude that XRCC1 Arg194Trp, and OGG1 Ser326Cys polymorphisms are not associated with RA; however, Arg399Gln polymorphism is a significant risk factor of RA, and carriers of 399Gln (G) allele have greater risk of RA.     

XPG Asp1104His基因多态性与中国人口结直肠癌易感性的关系

目的已有研究报道着色性干皮病基因（XPG）Asp1104His多态性与结直肠癌易感性相关,但是结果尚不一致。本研究旨在调查XPG Asp1104His基因多态性是否与中国人口的大肠癌易感性相关。 方法应用TaqMan分析法检测878例肠癌患者和884例同期住院的非肠癌患者XPG基因的Asp1104His多态性,并分析其与肠癌遗传易感性的相关性。同时我们用荟萃分析验证这一结果。 结果我们发现XPG Asp1104His基因多态性与大肠癌遗传易感性显著相关（显性模型：His/His＋Asp/His vs Asp/Asp,调整OR=1.39,95%CI=1.14~1.69）,分层分析结果显示His/His＋Asp/His基因型与中分化肠癌易感性相关。另外,我们的荟萃分析显示相似的结果：显性模型（OR=1.35,95%CI=1.20~1.51）在亚洲人口中与肠癌发病风险明显相关。 结论我们的结果表明：XPG Asp1104His基因多态性增加亚洲人罹患肠癌的风险。     

Polymorphisms in DNA repair genes XRCC1, XRCC3 and XPD, and colorectal cancer risk: a case–control study in an Indian population

Purpose

Genetic polymorphisms in DNA repair genes may influence variations in individual DNA repair capacity, which could be associated with the development of cancer. We detected the distributions of three single-nucleotide polymorphisms (XRCC1 Arg399Gln, XRCC3 Thr241Met and XPD Lys751Gln) in DNA repair genes, and assessed the associations of these genetic polymorphisms with colon and rectal cancer susceptibility as well as evaluated the interactions of gene–gene and gene–environment in a case–control study of an Indian population.

Methods

This case–control study was conducted with 302 cases (including 59 colon and 243 rectal cancer patients) and 291 cancer-free healthy controls. Genotypes were determined by PCR–RLFP assays. The effects [odds ratios (ORs) and 95% confidence intervals (95% CIs)] of genetic polymorphisms on colorectal cancer were estimated using unconditional logistic regression.

Results

The XRCC1 399Gln allele was found to be associated with a significantly increased rectal cancer risk among men (OR = 1.65, 95% CI 1.04–2.64). Whereas the XRCC3 241Met allele showed a protective tendency against rectal cancer (OR = 0.68, 95% CI 0.46–1.02) for both men and women. Furthermore, a combination of the XRCC1 399Gln allele with XRCC3 Thr/Thr genotype and the XPD 751Gln allele demonstrated the highest rectal cancer risk (OR = 3.52, 95% CI 1.43–9.44).

Conclusions

The combined effects of putative risk alleles/genotypes for different DNA repair pathways may strengthen the susceptibility to rectal cancer.     

Possible association of the X-ray cross complementing gene 1 (XRCC1) Arg280His polymorphism as a risk for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by the invasion of synovial cells into cartilage and bone, exhibiting certain features of transformed cells. To examine whether retardation of DNA repair pathway of oxidative damage is a possible mechanism in altered phenotypes of these cells, we analyzed SNPs of the base excision repair (BER) protein, X-ray repair cross complementing gene 1 (XRCC1), among RA patients. Genomic DNA was extracted from blood cells of 40 RA patients and SNPs of the three allele of the XRCC1 coding region (codons 194, 280 and 399) were determined by PCR, followed by sequencing. Of the three polymorphisms, only the XRCC1 Arg280His allele was associated with increased RA risk (odds ratio 13; 95% confidence interval 1.1–147) after adjustment for smoking. These data provide evidence for the first time that BER, which is involved in the recovery from oxidative damage, may correlate with RA.