The nonsynonymous single nucleotide polymorphisms of DNA repair geneXRCC1and susceptibility to the development of cervical carcinoma and high-risk human papillomavirus infection

Elucidation of Increased Cervical Cancer Risk Due to Polymorphisms in XRCC1 (R399Q and R194W), ERCC5 (D1104H), and NQO1 (P187S)

Genetic variations like single nucleotide polymorphisms (SNPs) are associated with cervical carcinogenesis. In this study, SNPs have been identified that contribute toward changes in the function and stability of the proteins and show association with cervical cancer. Initially, literature mining identified 114 protein-coding polymorphisms with population-based evidence in cervical cancer. Subsequently, the functional assessment was performed using sequence-dependent tools, and thereafter, protein stability was analyzed using sequence and structural data. Twenty-three non-synonymous SNPs (nsSNPs) found to be damaging and destabilizing were then analyzed to check their risk association at the population level. The meta-analysis indicated that polymorphisms in DNA damage repair genes XRCC1 (rs25487 and rs1799782), ERCC5 (rs17655), and oxidative stress-related gene NQO1 (rs1800566) are significantly associated with increased cervical cancer risk. The XRCC1 rs25487 and rs1799782 polymorphisms showed the highest risk of cervical cancer in the homozygous model having odds ratio (OR) = 1.85, 95% confidence interval (CI) = 1.17-2.92, p = 0.01, and recessive model with OR = 1.81, 95% CI = 1.01-3.24, and p = 0.04 respectively. Similarly, rs17655 polymorphism of ERCC5 and rs1800566 polymorphism of NQO1 showed the highest pooled OR in the homozygous (OR = 1.70, 95% CI = 1.32-2.19, p = 0.00004) and heterozygous model (OR = 1.3, 95% CI = 1.06-1.58, p = 0.01) respectively. Thus, in this study, a comprehensive collection of nsSNPs was collated and assessed, leading to the identification of polymorphisms in DNA damage repair and oxidative stress-related genes, that destabilize the protein and shows increased risk associated with cervical cancer.

Genetic polymorphisms in DNA repair genes and their association with risk of cervical cancer: A systematic review and meta-analysis

BACKGROUND

There have been a large number of epidemiologic studies regarding the association between genetic polymorphisms in DNA repair genes and onset of cervical cancer. However, results are inconsistent.

METHODS

Articles published before June 2021 and regarding genetic polymorphisms in DNA repair genes and cervical cancer were searched in following databases: PubMed, Web of Science, Google Scholar, and CNKI. With at least three articles for each polymorphism, we made meta-analysis to compute multivariate odds ratios (ORs) and their 95% confidence intervals (CIs).

RESULTS

The present study showed significant associations between XRCC1 Arg399Gln polymorphisms and risk of cervical cancer in Asian, whereas no significant association between them were showed in Caucasian (Asian: GA vs. GG: OR = 1.27, 95%CI 1.06-1.52; AA vs. GG: OR = 1.91, 95%CI 1.29-2.83; GA + AA vs. GG: OR = 1.36, 95%CI 1.12-1.65; AA vs. GG + GA: OR = 1.66, 95%CI 1.17-2.37; Caucasian: GA vs. GG: OR = 1.08, 95%CI 0.83-1.41; AA vs. GG: OR = 2.18, 95%CI 0.75-6.31; GA + AA vs. GG: OR = 1.23, 95%CI 0.85-1.78; AA vs. GG + GA: OR = 1.70, 95%CI 0.69-4.18). In addition, there were significant associations between ERCC2 rs13181 polymorphisms and risk of cervical cancer in Asian (AC vs AA: OR = 0.53, 95%CI 0.37-0.75, I²  = 0.0%, p value of Q test = 0.847; AC + CC vs AA: OR = 0.50, 95%CI 0.36-0.70, I²  = 0.0%, p value of Q test = 0.856).

CONCLUSIONS

The meta-analysis showed that there were significant associations between XRCC1 Arg399Gln and ERCC2 rs13181 polymorphisms and risk of cervical cancer.

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.

Distribution of nucleotide variants in the DNA sequence of ERCC1 and XRCC1 genes and the effect of phenotype in patients with gastric cancer

BACKGROUND/AIMS

Gastric cancers vary across countries and ethnic groups. They are the second most common type of cancer worldwide. Dietary and non-dietary factors as well as genetic and epigenetic alterations of many mechanisms are implicated in the development of gastric cancer. We aimed to determine the sequence of possible nucleotide changes, polymorphisms, and mutations, and to establish genotype and phenotype relation by performing whole DNA sequence analysis of the XRCC1 and ERCC1 genes belonging to base excision repair (BER) and nucleotide excision repair (NER) family of DNA repair genes in patients with gastric cancer.

MATERIALS AND METHODS

We included 50 patients of both sexes who had received diagnosis of gastric cancer and 50 healthy people who showed same demographic traits that forms the control group. We analyzed the ERCC1 and XRCC1 genes by DNA sequence analysis on both groups. After the analysis, we compared the genotype-phenotype relation.

RESULTS

Neither patients nor the control group has any nucleotide replacement in any exon of ERCC1 genes. We could not detect significant difference between patients and healthy groups when we correlated genotype contribution of mutations Arg194Trp, Arg208His, Arg399Gln detected in the XRCC1 gene and allele frequency.

CONCLUSION

According to our study, the ERCC1 gene in Turkish population is not getting mutation in patients with gastric cancer and healthy individuals. Three mutations were detected in the XRCC1 gene, and these mutations were not associated with gastric cancer.

Meta-analysis of XRCC1 polymorphism and risk of female reproductive system cancer

Numerous epidemiological studies have evaluated the association between polymorphism in the gene encoding x-ray repair cross complementing 1 (XRCC1) protein and the risk of female reproductive system cancer, but results are inconclusive. To gain a comprehensive picture of available evidence, we searched for relevant studies in the PubMed, EMBASE, Scopus, and Chinese National Knowledge Infrastructure databases up to December 17, 2016. A total of 26 case-control studies were picked out. The pooled odds ratio (OR) with its 95% confidence interval (CI) was calculated to estimate the association. Based on data of all study participants, we did not find a positive association of rs25487 or rs1799782 polymorphism with risk of female reproductive cancer risk. Subgroup analysis, however, identified two alleles as being associated with an increased risk of female reproductive system cancer in Asians: the A allele of rs25487 (heterozygous genetic model, OR 1.16, 95%CI 1.00-1.36), and the T allele of rs1799782 (homozygous model, OR 2.30, 95%CI 1.39-3.82; dominant model, OR 1.28, 95%CI 1.10-1.50; recessive model, OR 2.11, 95%CI 1.33-3.34). Moreover, the AA genotype at rs25489 was determined to be a risk factor for cervical cancer etiology (homozygous model, OR 2.91, 95%CI, 1.17-7.26; recessive model, OR 3.16, 95%CI 1.91-5.24). This meta-analysis suggests that no association between rs25487 or rs1799782 gene polymorphism and risk of female reproductive cancer risk was found. These results should be validated in larger studies.

Association between XRCC1 polymorphisms and the risk of cervical cancer: a meta-analysis based on 4895 subjects

The present meta-analysis was intended to explore the relationship between the X-ray repair cross complementing 1 (XRCC1) polymorphisms (Arg194Trp, Arg280His and Arg399Gln) and cervical cancer risk. Several electronic databases were searched systematically and bibliographies of relevant papers were identified carefully. Then, a meta-analysis was performed based on eligible studies in various genetic models. Pooled odds ratios (OR) with 95% confidence intervals (95% CI) were employed to evaluate the strength of associations between the XRCC1 polymorphisms and cervical cancer risk. Additionally, heterogeneity analysis and sensitivity analysis were done if necessary. Totally, 11 articles involving 2092 cases and 2803 controls were included. Taken together, there was no obvious association between the Arg194Trp or Arg280His polymorphism and cervical cancer risk. Considering the great heterogeneity, subgroup analysis was done, but the pooled result remained stable. Nevertheless, the association between the Arg399Gln polymorphism and cervical cancer risk showed distinct statistic significance in the allele model, dominant model, homozygous model and heterozygous model. In view of the exiting heterogeneity, we did subgroup analysis stratified by ethnicity, resulting in the fact that the Arg399Gln polymorphism was related to the decreased risk of cervical cancer. The Begg's test and Egger's test were used to find no publication bias. To conclude, the current meta-analysis indicated that the XRCC1 Arg399Gln polymorphism decreased the risk of cervical cancer, while the Arg194Trp and Arg280His polymorphisms were not associated with cervical caner risk. Certainly, a well-designed large-scale multicenter study is warranted to confirm the finding.

Genetic Polymorphisms in XRCC1, CD3EAP, PPP1R13L, XPB, XPC, and XPF and the Risk of Chronic Benzene Poisoning in a Chinese Occupational Population

Objectives

Individual variations in the capacity of DNA repair machinery to relieve benzene-induced DNA damage may be the key to developing chronic benzene poisoning (CBP), an increasingly prevalent occupational disease in China. ERCC1 (Excision repair cross complementation group 1) is located on chromosome 19q13.2–3 and participates in the crucial steps of Nucleotide Excision Repair (NER); moreover, we determined that one of its polymorphisms, ERCC1 rs11615, is a biomarker for CBP susceptibility in our previous report. Our aim is to further explore the deeper association between some genetic variations related to ERCC1 polymorphisms and CBP risk.

Methods

Nine single nucleotide polymorphisms (SNPs) of XRCC1 (X-ray repair cross-complementing 1), CD3EAP (CD3e molecule, epsilon associated protein), PPP1R13L (protein phosphatase 1, regulatory subunit 13 like), XPB (Xeroderma pigmentosum group B), XPC (Xeroderma pigmentosum group C) and XPF (Xeroderma pigmentosum group F) were genotyped by the Snapshot and TaqMan-MGB^® probe techniques, in a study involving 102 CBP patients and 204 controls. The potential interactions between these SNPs and lifestyle factors, such as smoking and drinking, were assessed using a stratified analysis.

Results

An XRCC1 allele, rs25487, was related to a higher risk of CBP (P<0.001) even after stratifying for potential confounders. Carriers of the TT genotype of XRCC1 rs1799782 who were alcohol drinkers (OR = 8.000; 95% CI: 1.316–48.645; P = 0.022), male (OR = 9.333; 95% CI: 1.593–54.672; P = 0.019), and had an exposure of ≤12 years (OR = 2.612; 95% CI: 1.048–6.510; P = 0.035) had an increased risk of CBP. However, the T allele in PPP1R13L rs1005165 (P<0.05) and the GA allele in CD3EAP rs967591 (OR = 0.162; 95% CI: 0039~0.666; P = 0.037) decreased the risk of CBP in men. The haplotype analysis of XRCC1 indicated that XRCC1 rs25487^A, rs25489^G and rs1799782^T (OR = 15.469; 95% CI: 5.536–43.225; P<0.001) were associated with a high risk of CBP.

Conclusions

The findings showed that the rs25487 and rs1799782 polymorphisms of XRCC1 may contribute to an individual’s susceptibility to CBP and may be used as valid biomarkers. Overall, the genes on chromosome 19q13.2–3 may have a special significance in the development of CBP in occupationally exposed Chinese populations.

Association between the XRCC1 Arg194Trp polymorphism and risk of cancer: evidence from 201 case-control studies

The Arg194Trp polymorphism in the X-ray cross-complementing group 1 (XRCC1) had been implicated in cancer susceptibility. The previous published data on the association between XRCC1 Arg194Trp polymorphism and cancer risk remained controversial. Hence, we performed a meta-analysis to investigate the association between cancer susceptibility and XRCC1 Arg194Trp (59,227 cases and 81,587 controls from 201 studies) polymorphism in different inheritance models. We used odds ratios with 95 % confidence intervals to assess the strength of the association. Overall, significantly increased cancer risk was found (recessive model: (odds ration [OR] = 1.18, 95% confidence interval [CI] = 1.09-1.27; homozygous model: OR = 1.21, 95% CI = 1.10-1.33; additive model: OR = 1.05, 95% CI = 1.01-1.09) when all eligible studies were pooled into the meta-analysis. In further stratified and sensitivity analyses, significantly increased glioma risk was found among Asians, significantly decreased lung cancer risk was found among Caucasians, and significant increased breast cancer risk was found among hospital-based studies. In summary, this meta-analysis suggests that Arg194Trp polymorphism may be associated with increased breast cancer risk, Arg194Trp polymorphism is associated with increased glioma risk among Asians, and Arg194Trp polymorphism is associated with decreased lung cancer risk among Caucasians. In addition, our work also points out the importance of new studies for Arg194Trp association in some cancer types, such as gastric, pancreatic, prostate, and nasopharyngeal cancers, where at least some of the covariates responsible for heterogeneity could be controlled, to obtain a more conclusive understanding about the function of the XRCC1 Arg194Trp polymorphism in cancer development (I (2) > 75%).

Association of XRCC1 polymorphisms with thyroid cancer risk

Due to the important role in the DNA repair pathways, numerous studies have been carried out to explore the relationship between the polymorphisms in the X-ray repair cross-complementing group 1 (XRCC1) gene and thyroid cancer risk. But previous reports have produced conflicting results. Thus, we performed an updated comprehensive meta-analysis to better investigate the association of the XRCC1 polymorphisms with thyroid cancer risk. There were a total of nine studies included with 1,621 cases and 3,669 controls examining the effects of the XRCC1 Arg280His, Arg399Gln, and Arg194Trp polymorphisms on the susceptibility of thyroid cancer. In our study, the XRCC1 Arg280His polymorphism was found to be associated with an increased thyroid cancer risk in the Caucasian population [allelic contrast: odds ratio (OR) = 1.38, 95% CI = 1.05-1.80, P(Z) = 0.02, P(Q) = 0.61; dominant model: OR = 1.43, 95% CI = 1.08-1.89, P(Z) = 0.01, P(Q) = 0.57]. The Arg399Gln polymorphism was associated with a significant decreased risk [allelic contrast: OR = 0.73, 95% CI = 0.59-0.92, P(Z) = 0.006, P(Q) = 0.31; dominant model: OR = 0.73, 95% CI = 0.55-0.97, P(Z) = 0.03, P(Q) = 0.33; recessive model: OR = 0.56, 95% CI = 0.34-0.93, P(Z) = 0.02, P(Q) = 0.59], while the Arg194Trp SNP conferred an increased risk for thyroid cancer in the mixed populations [allelic contrast: OR = 1.49, 95% CI = 1.02-2.17, P(Z) = 0.04]. To conclude, the present meta-analysis demonstrated that the polymorphisms in the XRCC1 gene may be associated with developing of thyroid cancer.

Genome stability pathways in head and neck cancers

Genomic instability underlies the transformation of host cells toward malignancy, promotes development of invasion and metastasis and shapes the response of established cancer to treatment. In this review, we discuss recent advances in our understanding of genomic stability in squamous cell carcinoma of the head and neck (HNSCC), with an emphasis on DNA repair pathways. HNSCC is characterized by distinct profiles in genome stability between similarly staged cancers that are reflected in risk, treatment response and outcomes. Defective DNA repair generates chromosomal derangement that can cause subsequent alterations in gene expression, and is a hallmark of progression toward carcinoma. Variable functionality of an increasing spectrum of repair gene polymorphisms is associated with increased cancer risk, while aetiological factors such as human papillomavirus, tobacco and alcohol induce significantly different behaviour in induced malignancy, underpinned by differences in genomic stability. Targeted inhibition of signalling receptors has proven to be a clinically-validated therapy, and protein expression of other DNA repair and signalling molecules associated with cancer behaviour could potentially provide a more refined clinical model for prognosis and treatment prediction. Development and expansion of current genomic stability models is furthering our understanding of HNSCC pathophysiology and uncovering new, promising treatment strategies.

X-ray repair cross-complementing group 1 (XRCC1) genetic polymorphisms and cervical cancer risk: a huge systematic review and meta-analysis

BACKGROUND

Previous studies investigating the association between X-ray repair cross-complementation group 1(XRCC1) polymorphisms and cervical cancer (CC) risk has provided inconsistent results. The aim of our study was to assess the association between the XRCC1 gene Arg399Gln, Arg194Trp, Arg280His polymorphisms and risk of CC.

METHODS

Two investigators independently searched the Medline, Embase, CNKI, and Chinese Biomedicine Databases for studies published before March 2011.Summary odds ratios (ORs) and 95% confidence intervals (CIs) for XRCC1 polymorphisms and CC were calculated in a fixed-effects model or a random-effects model when appropriate.

RESULTS

Ultimately, 9, 5 and 2 studies were found to be eligible for meta-analyses of Arg399Gln, Arg194Trp and Arg280His, respectively. Our analysis suggested that the variant genotypes of Arg194Trp were associated with a significantly increased CC risk (Trp/Trp vs Arg/Arg, OR = 2.21, 95% CI = 1.60-3.06; Arg/Trp vs Arg/Arg, OR = 1.23, 95% CI = 1.02-1.49; dominant model, OR = 1.36, 95% CI = 1.14-1.63; recessive model, OR = 2.06, 95% CI = 1.51-2.82). For Arg280His polymorphism, no obvious associations were found for all genetic models. For Arg399Gln polymorphism, also no obvious associations were found for all genetic models. In the subgroup analyses by ethnicity/country, a significantly increased risk was observed among Asian, especially among Chinese. To get more precise evidences, adjusted ORs (95%CI) by potential confounders (such as age, ethnicity or smoking, etc) were also calculated for XRCC1 Arg399Gln and Arg194Trp, however, the estimated pooled adjusted OR still did not change at all.

CONCLUSION

This meta-analysis suggests that Arg194Trp polymorphism may be associated with CC risk, Arg399Gln polymorphism might be a low-penetrent risk factor for CC only in Asians, and there may be no association between Arg280His polymorphism and CC risk.

Involvement of the XRCC1 Arg399Gln gene polymorphism in the development of cervical carcinoma

BACKGROUND

Although infection with the human papillomavirus (HPV) is crucial to the development of cervical cancer, it is not considered a sufficient isolated factor to cause this malignancy. The association of the XRCC1 Arg399Gln (rs25487) polymorphism with cervical cancer has been demonstrated in some populations.

METHODS

The XRCC1 Arg399Gln genetic variants were identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in patients with advanced cervical cancer (n=189) and controls (n=308).

RESULTS

We observed that patients with advanced cervical cancer having the Gln/Gln or Gln/Arg vs Arg/Arg genotype displayed a 1.726-fold increased risk of cervical cancer (95% confidence interval [CI]=1.158-2.572, p=0.007). The odds ratio (OR) for Gln/Gln vs Gln/Arg or Arg/Arg was 1.742 (95% CI=1.073-2.827; p=0.0236). We also found a significantly higher frequency of the XRCC1 399Gln allele in patients with cancer than in controls, with OR=1.489 (95% CI=1.148-1.930, p=0.0026). The p value of the chi-square test for the trend observed for the XRCC1 Arg399Gln polymorphism was also statistically significant (ptrend=0.002). The statistical power of this study amounted to 78% for the Gln/Gln or Gln/Arg genotypes and 61% for the Gln/Gln genotype.

CONCLUSION

Although the statistical power of our study did not reach 80%, we found a statistically significant association between the XRCC1 399Gln variant and the incidence of cervical cancer.

The Arg194Trp polymorphism in the XRCC1 gene and cancer risk in Chinese Mainland population: a meta-analysis

The Arg194Trp polymorphism in the X-ray repair cross-complementing group 1 (XRCC1) gene has been proved to be in association with cancer risk in Chinese Mainland population, but a large number of studies have reported inconclusive results. A more comprehensive and precise estimation of the relationship is needed to clear the way towards future studies. Thus, we performed a meta-analysis to analysis these associations. A total of 34 case-control studies in 34 articles were included in this meta-analysis. The results showed that the 194Trp/Trp homozygote had a 31% increased risk of cancer than 194Trp/Arg and 194Arg/Arg genotypes, OR was 1.31 and 95%CI was 1.13 to 1.53. In the subgroup analysis by cancer sites, the Arg194Trp polymorphism was associated with increased risks of lung cancer (OR = 1.27 and 95%CI: 1.07-1.50 for Trp/Trp versus Arg/Arg + Arg/Trp) and esophageal cancer (OR = 1.68 and 95%CI: 1.33-2.13 for Trp/Trp versus Arg/Arg + Arg/Trp). This meta-analysis suggested that the Arg194Trp polymorphism of the XRCC1 gene is a cancer susceptible factor among Chinese Mainland population. More intensive and deeper studies are needed to further reveal the mechanism between Arg194Trp polymorphisms of XRCC1 gene and cancer risks in Chinese Mainland population.

Association between genetic polymorphisms of DNA base excision repair genes and evolution of precancerous gastric lesions in a Chinese population

Base excision repair pathway may play an important role in repairing DNA damage related to Helicobacter pylori-induced inflammatory process. To evaluate the association between genetic polymorphisms of X-ray repair cross-complementing group 1 (XRCC1, Arg194Trp and Arg399Gln), adenosine diphosphate ribosyl transferase (ADPRT, Val762Ala), 8-oxoguanine DNA glycosylase (OGG1, Ser326Cys) and apurinic/apyrimidinic endonuclease 1 (APE1, Asp148Glu) and evolution of H.pylori-associated precancerous gastric lesions, a population-based cohort study was conducted in Linqu County, a high-risk area of gastric cancer in China. Genotypes were determined by polymerase chain reaction (PCR)-based denaturing high-performance liquid chromatography and PCR-restriction fragment length polymorphism analysis in 1281 H.pylori-infected subjects. We found that subjects carrying the combined XRCC1-194Arg/Trp+Trp/Trp genotype had an elevated chance of regression of gastric lesions [adjusted odds ratio (OR) = 1.44; 95% confidence interval (CI) = 1.06-1.96], whereas subjects carrying the XRCC1-399Arg/Gln+Gln/Gln genotype had a decreased chance of regression (OR = 0.68; 95% CI = 0.49-0.92). Stratified analysis indicated that an increased risk of progression was observed in subjects carrying the XRCC1-399Arg/Gln+Gln/Gln genotype (OR = 1.60; 95% CI = 1.09-2.36) or OGG1-326Ser/Cys+Cys/Cys genotype (OR = 1.95; 95% CI = 1.03-3.71) with intestinal metaplasia or dysplasia at baseline or carrying the XRCC1-399Arg/Gln+Gln/Gln genotype and smoking (OR = 1.58; 95% CI = 1.02-2.45). Furthermore, a significantly increased risk of progression was observed in subjects carrying one or two hazard genotypes of XRCC1-399 or OGG1-326, the OR was 2.83 (95% CI = 1.32-6.08), 2.22 (95% CI = 1.24-3.98) or 2.27 (95% CI = 1.26-4.10), respectively. These findings suggest that genetic polymorphisms in XRCC1-Arg194Trp, XRCC1-Arg399Gln and OGG1-Ser326Cys may play important roles in the evolution of H.pylori-associated gastric lesions in this high-risk population.

Association between polymorphisms in DNA base excision repair genes XRCC1, APE1, and ADPRT and differentiated thyroid carcinoma

PURPOSE

DNA BER pathway is related with carcinogenesis. We hypothesized that functional polymorphisms of three BER genes, XRCC1, apurinic/apyrimidinic endonuclease (APE1), and ADPRT, confer risks for DTC and its progression.

EXPERIMENTAL DESIGN

Five common nonsynonymous single nucleotide polymorphisms (Arg194Trp, Arg280His, and Arg399Gln for XRCC1; Asp148Glu for APE1; and Val762Ala for ADPRT) were genotyped in Chinese DTC cases and controls.

RESULTS

The XRCC1-194Trp/Trp genotype showed a significantly increased risk for DTC (odds ratio, 1.85; 95% confidence interval, 1.11-3.07; P = 0.018). Subset analysis based on regional LN metastasis showed that the genetic effect came primarily from the subjects with LN metastasis (odds ratio, 4.54; 95% confidence interval, 2.11-9.79; P = 0.0001), but no significant association for subjects without LN metastasis. The other four single nucleotide polymorphisms did not show significant results. Haplotype analysis of XRCC1 polymorphisms yielded a significant result (P = 0.004), especially in the subjects with LN metastasis (P = 0.0002). Moreover, we found that XRCC1-194Trp and ADPRT-762Ala variants collectively contributed to an increased risk of the disease and LN metastasis, with the combined variant homozygotes exhibiting the highest 3.18-fold risk for DTC (P = 0.046) and 9.25-fold risk for DTC with LN metastasis (P = 0.004).

CONCLUSIONS

The XRCC1 polymorphisms, especially the 194Trp allele, may have an effect on DTC development and progression. This variant can interact with ADPRT-762Ala variant to further substantially increase susceptibility to the disease and regional LN metastasis. Identifying these risk genetic markers could provide more insight into the DTC pathogenesis and may also provide information to develop better prevention and therapeutic strategies.