Polymorphisms in DNA repair genes and susceptibility to glioma in a chinese population

XRCC1: a potential prognostic and immunological biomarker in LGG based on systematic pan-cancer analysis

X-ray repair cross-complementation group 1 (XRCC1) is a pivotal contributor to base excision repair, and its dysregulation has been implicated in the oncogenicity of various human malignancies. However, a comprehensive pan-cancer analysis investigating the prognostic value, immunological functions, and epigenetic associations of XRCC1 remains lacking. To address this knowledge gap, we conducted a systematic investigation employing bioinformatics techniques across 33 cancer types. Our analysis encompassed XRCC1 expression levels, prognostic and diagnostic implications, epigenetic profiles, immune and molecular subtypes, Tumor Mutation Burden (TMB), Microsatellite Instability (MSI), immune checkpoints, and immune infiltration, leveraging data from TCGA, GTEx, CELL, Human Protein Atlas, Ualcan, and cBioPortal databases. Notably, XRCC1 displayed both positive and negative correlations with prognosis across different tumors. Epigenetic analysis revealed associations between XRCC1 expression and DNA methylation patterns in 10 cancer types, as well as enhanced phosphorylation. Furthermore, XRCC1 expression demonstrated associations with TMB and MSI in the majority of tumors. Interestingly, XRCC1 gene expression exhibited a negative correlation with immune cell infiltration levels, except for a positive correlation with M1 and M2 macrophages and monocytes in most cancers. Additionally, we observed significant correlations between XRCC1 and immune checkpoint gene expression levels. Lastly, our findings implicated XRCC1 in DNA replication and repair processes, shedding light on the precise mechanisms underlying its oncogenic effects. Overall, our study highlights the potential of XRCC1 as a prognostic and immunological pan-cancer biomarker, thereby offering a novel target for tumor immunotherapy.

Association between XRCC3 p.Thr241Met polymorphism and risk of glioma: A systematic review and meta-analysis

BACKGROUND

The XRCC3 p.Thr241Met (rs861539) polymorphism has been extensively studied for its association with glioma risk, but results remain conflicting. Therefore, we performed a systematic review and meta-analysis to resolve this inconsistency.

METHODS

Studies published up to June 10, 2022, were searched in PubMed, Web of Science, Scopus, VIP, Wanfang, and China National Knowledge Infrastructure databases and screened for eligibility. Then, the combined odds ratio (OR) of the included studies was estimated based on five genetic models, i.e., homozygous (Met/Met vs. Thr/Thr), heterozygous (Thr/Met vs. Thr/Thr), dominant (Thr/Met + Met/Met vs. Thr/Thr), recessive (Met/Met vs. Thr/Thr + Thr/Met) and allele (Met vs. Thr). The study protocol was preregistered at PROSPERO (registration number: CRD42021235704).

RESULTS

Overall, our meta-analysis of 14 eligible studies involving 12,905 subjects showed that the p.Thr241Met polymorphism was significantly associated with increased glioma risk in both homozygous and recessive models (homozygous, OR = 1.381, 95% CI = 1.081-1.764, P = 0.010; recessive, OR = 1.305, 95% CI = 1.140-1.493, P<0.001). Subgroup analyses by ethnicity also revealed a statistically significant association under the two aforementioned genetic models, but only in the Asian population and not in Caucasians (P>0.05).

CONCLUSION

We demonstrated that the XRCC3 p.Thr241Met polymorphism is associated with an increased risk of glioma only in the homozygous and recessive models.

Association between Single Nucleotide Polymorphisms and Glioma Risk: A Systematic Literature Review

This study aimed to determine the main single nucleotide polymorphisms (SNPs) that are associated with an increased or decreased risk of glioma development in healthy individuals. We conducted a systematic review of the articles published in English on the PUBMED database between January 2008 and December 2017. Our search resulted in a total of 743 articles; however, only 56 were included in this review. A total of 148 polymorphisms were found, which involved 64 different genes. The polymorphisms that were most associated with an increased risk of glioma development were polymorphic variants rs179782, rs13181, and rs3791679 of the genes XRCC1, ERCC2, and EFEMP1, respectively.

Association between common polymorphisms in ERCC gene and glioma risk: A meta-analysis of 15 studies

BACKGROUND

A number of studies have investigated the roles of excision repair cross complementation group 1 (ERCC1), ERCC2, and ERCC5 genes polymorphisms in the development of glioma; however, the results were inconsistent. Here, we performed a meta-analysis to investigate the association between 6 polymorphisms in the ERCC genes (rs3212986, rs11615, rs13181, rs1799793, rs238406, rs17655) and glioma risk.

METHODS

The PubMed, Embase, and Web of science were searched up to September 6, 2016, for studies on the association between ERCC polymorphisms and glioma risk. A fixed-effects or random-effects model was used to calculate the pooled odds ratios based on the results from the heterogeneity tests. Sensitivity and cumulative meta-analyses were also performed.

RESULTS

A total of 15 studies were eligible for the pooled analysis, conducted in 2 populations of ethnic descent: 8 Europeans and 7 Asians. The results showed that ERCC1 rs3212986 polymorphism was positively associated with glioma [AA vs CC: odds ratio (OR) = 1.298, 95% confidence interval (95% CI) = 1.043-1.230, P = .025]. Association of the ERCC2 rs13181 and rs1799793 polymorphisms was only observed in Asians (CC vs AA for rs13181: OR = 1.539, 95% CI = 1.122-2.109, P = .007; AA vs GG for rs1799793: OR = 1.474, 95% CI = 1.090-1.994, P = .012). However, no association was observed between glioma risk and ERCC1 rs11615, ERCC2 rs238406, and ERCC5 rs17655 polymorphisms. Moreover, sensitivity and cumulative meta-analyses confirmed the stability of the results.

CONCLUSIONS

Our meta-analysis indicated that the ERCC1 rs3212986 polymorphism and 2 polymorphisms in ERCC2 gene (rs13181 and rs1799793) contributed to the susceptibility of glioma.

Reappraisal of XRCC1 Arg194Trp polymorphism and glioma risk: a cumulative meta-analysis

The association between XRCC1 Arg194Trp polymorphism and glioma risk were inconsistent from published meta-analyses and epidemiological studies. Hence, we performed this updated and cumulative meta-analysis to reappraisal this relationship. PubMed, Embase, CBM (Chinese Biomedical Database), and CNKI (China National Knowledge Internet) databases were comprehensively searched up to August 13, 2016 (updated on December 22, 2016). After study selection and data extraction from eligible studies, the association was evaluated by odds ratios (ORs) and its 95% confidence intervals (95%CIs) using Comprehensive Meta-Analysis software. Finally 16 case-control studies involving 7011 patients and 9519 healthy controls were yielded. The results indicated that XRCC1 Arg194Trp polymorphism was significantly correlated with the increased risk of glioma [Trp vs. Arg: OR = 1.18(1.05-1.34); TrpTrp vs. ArgArg: OR = 1.66(1.31-2.12); ArgTrp vs. ArgArg: OR = 1.34(1.02-1.77); TrpTrp vs. ArgArg+ArgTrp: OR = 1.47(1.26-1.72); TrpTrp+ArgTrp vs. ArgArg: OR = 1.17(1.01-1.35)]. Cumulative analysis showed the results changed from non-significant to significant when new studies accumulated, and sensitivity analysis indicated the results were stable. Subgroup analysis showed the significant association existed in Asians but not in Caucasians. Current evidence indicated that XRCC1 Arg194Trp polymorphism was associated with increased risk for glioma, especially in Asians; however, relevant studies involving other ethnic groups are required to validate our findings in further.

Polymorphisms in DNA Repair Gene and Susceptibility to Glioma: A Systematic Review and Meta-Analysis Based on 33 Studies with 15 SNPs in 9 Genes

At present, many publications have evaluated the correlation between the DNA repair gene polymorphisms and glioma susceptibility. However, the results remain inconclusive. The aim of this research is to exhaustively assess the association of genetic polymorphisms in DNA repair genes with glioma risk in human. Meta-analysis method was conducted, and 33 studies with 15 SNPs in 9 genes were included (12553 glioma cases and 17178 controls). Correlation strength was evaluated by odds ratio with a 95 % confidence interval. Rs1799782 T allele and rs25487A allele might bring about higher risk of glioma in Asian population. Rs1805377 G allele was an increased risk genetic factor of glioma. Asian carried with rs3212986 A allele was more likely to have glioma. Rs1800067 G allele was a risk factor of developing glioma. Carriers with rs12917 CC genotype in MGMT gene had higher risk of glioma in Caucasian than other non-CC genotype carriers. Carriers with rs1136410 T allele in PARP1 gene could more likely to develop glioma in Caucasian. This meta-analysis suggests that glioma susceptibility is associated with rs1799782 and rs25487 of X-ray repair complementing defective repair in Chinese hamster cells 1 (XRCC1), rs1805377 of XRCC4, rs1800067 of excision repair cross-complementing rodent repair deficiency complementation group 4 (ERCC4) and rs3212986 of ERCC1 in Asian population, and rs12917 of O-6-methylguanine-DNA methyltransferase (MGMT) and rs1136410 of poly(ADP-ribose) polymerase 1 (PARP1) in Caucasian population.

A Comprehensive Meta-analysis of Genetic Associations Between Key Polymorphic Loci in DNA Repair Genes and Glioma Risk

Genetic variants found in DNA repair genes (ERCC1, rs3212986; ERCC2, rs13181; ERCC4, rs1800067; ERCC5, rs17655; XRCC1, rs1799782, rs25487, rs25489; XRCC3, rs861539) have been reported to have an ambivalent association with the development of glioma. In the present study, a meta-analysis was conducted to confirm the relationship, taking heterogeneity of population into consideration. We analyzed 21 articles of 6 genes along with 8 single nucleotide polymorphisms (SNPs) (24,078 cases and 30,926 healthy individuals), which assessed the relationship between nucleotide excision, base excision, double-strand break repair gene, and the development of glioma under five models. All statistical analysis was implemented by the software of R 3.2.1, and the relationships between key polymorphic loci in DNA repair genes and glioma were quantified by the pooled odds ratio (OR) and 95 % confidential intervals. Overall, the synthesized evidence demonstrated that the SNP of rs13181 and rs1799782 significantly increased the risk of glioma whereas SNP of rs1800067 were significantly associated with a decrease in the risk of glioma. Additionally, subgroup analyses of 8 SNPs by ethnicity indicated that the mutation of rs13181, rs1800067 were apparently protective factors of glioma among Asians, while the mutation of rs13181 was a risk factors of glioma in Caucasians. Furthermore, the mutation of rs1799782 significantly raises the risk of glioma for Asian. Our study suggested that rs13181*C and rs1799782*A are risk alleles for glioma; rs1800067*A are beneficial alleles for decreased susceptibility to glioma. Future studies with large sample size and other races are strongly recommended to confirm the results from this study.

Association between X-ray repair cross-complementing group 1 gene polymorphisms and glioma risk: a systematic review and meta-analysis based on 22 case-control studies

OBJECTIVES

Glioma is the most common central nervous system tumor. This systematic review and meta-analysis is aimed to systematically assess the association of XRCC1 polymorphisms with the risk of glioma.

METHODS

Such databases as EMbase, PubMed, The Cochrane Library, the China National Knowledge Infrastructure (CNKI) platforms, VIP and WanFang were searched up to April 2015 to collect case-control studies of association between XRCC1 polymorphisms and glioma. Data were extracted and meta-analysis was conducted by using Stata 12.0 softwares.

RESULTS

A total of 22 studies were included in the meta-analysis, including 18503 glioma patients and 24367 controls. The overall data indicated that XRCC1 Arg194Trp (C>T) polymorphism significantly increased glioma risk (allele C versus T: OR=0.72, 95% CI=0.55-0.93, CC versus TT: OR=0.55, 95% CI=0.46-0.67; CC versus CT+TT: OR=0.64, 95% CI=0.45-0.91 and CC+CT vs. TT: OR=0.61, 95% CI=0.51-0.74), especially in Asia ethnicity. XRCC1 Arg280His (G>A) polymorphism has no association with glioma (allele G versus A: OR=1.01, 95% CI=0.83-1.22; GG versus AA: OR=1.07, 95% CI=0.66-1.75; GA versus AA: OR=1.01, 95% CI=0.77-1.32; GG versus GA+AA: OR=1.01, 95% CI=0.84-1.22 and GG+GT versus AA: OR=1.06, 95% CI=0.67-1.69). XRCC1 Arg399Gln (G>A) polymorphism will significantly increase glioma risk in Asian (allele G versus A: OR=0.78, 95% CI= 0.72-0.84; GG versus AA: OR=0.56, 95% CI=0.47-0.66; GA versus AA OR=0.71, 95% CI=0.59-0.84; GG versus GA+AA: OR=0.76, 95% CI=0.68-0.84 and GG+GA vs. AA: OR=0.62, 95% CI=0.53-0.73) but not Caucasian ethnicity. XRCC1 Pro161Leu (C>T), Leu387Leu (G>A), Pro602Thr (C>A), Ser593Arg (C>G) and Glu491Lys (G>A) polymorphisms increased glioma risk in different degrees.

CONCLUSION

This meta-analysis suggested that XRCC1 Arg194Trp and XRCC1 Arg399Gln (G>A) polymorphisms led to susceptibility to glioma in Asian but not Caucasian population. XRCC1 Glu491Lys (G>A), Pro161Leu (C>T), Leu387Leu (G>A), Pro602Thr (C>A), Thr304Ala (A>G) and Ser593Arg (C>G) polymorphisms will increase glioma risk. However, XRCC1 Arg280His (G>A) is irrelevant to the increased or decreased glioma risk.

A Comprehensive Analysis of Influence ERCC Polymorphisms Confer on the Development of Brain Tumors

Within DNA repair genes, there lie a number of single nucleotide polymorphisms that may impair protein function and attenuate DNA repair capability, resulting in genomic instability and individual predisposition to malignancies. The purpose of this study was to assess the previously reported inconsistent association of polymorphisms in ERCC1 (rs11615, rs3212986), ERCC2 (rs13181, rs1799793, rs238406), and ERCC5 (rs17655) with the development of brain tumors. In the present work, we carried out a comprehensive meta-analysis of results from all published data (5 data sets for rs11615, 7 for rs3212986, 11 for rs13181, 5 for rs1799793, 3 for rs238406, and 4 for rs17655) to evaluate risk of brain tumors contributed by the polymorphisms being investigated. Either the analytic method described by Mantel and Haenszel or that proposed by DerSimonian and Laird was properly used to summarize the risk estimates (OR and 95% CI). Data analyses were done with Stata version 12.0. Meta-analyses were performed for all polymorphisms, and only rs3212986 in the ERCC1 gene showed a significant association with glioma incidence. In the homozygote comparison, we found 1.26-fold elevated risk of glioma in relation to presence of the AA genotype (OR = 1.26, 95% CI = 1.05-1.52, P OR = 0.013, P heterogeneity = 0.849, I(2) = 0.0%). We also noted that individuals with the rs3212986-AA as compared to those with rs3212986-CC/CA had a 28% higher risk to develop glioma (OR = 1.28, 95% CI = 1.06-1.53, P OR = 0.008, Pheterogeneity = 0.808, I(2) = 0.0%). No major effects were observed for Caucasians or Asians in subgroup analysis by ethnicity. ERCC1 rs3212986 is a common single nucleotide polymorphism and may contribute toward individual susceptibility for glioma. Further research in this filed is required to verify the association obtained based on a relatively small number.

DNA repair gene ERCC1 polymorphisms and glioma susceptibility among Chinese population: a meta-analysis

BACKGROUND

Excision repair cross complementation group 1 (ERCC1) has been shown to be involved in the progression of glioma susceptibility. However, the results remain conflict. The aim of this study was to systematically review and evaluate the role of ERCC1 C118T and C8092A polymorphisms in glioma risk among Chinese population.

METHODS

Related case-control studies were searched in online electronic databases. Odds ratio (OR) with its 95% confidence interval (CI) were employed to calculate the extracted data.

RESULTS

Total seven articles were retrieved, including 4426 subjects (1926 were glioma patients and 2500 were matched controls). No significant heterogeneity was found between studies (I(2)=0%, P>0.01). Our results demonstrated that A allele and AA genotype of ERCC1 C8092A polymorphism have a positive association with increasing the risk of glioma in the fixed-effect model (A vs. C: OR=1.13, 95% CI=1.02-1.25, P=0.02; AA vs. CC: OR=1.29, 95% CI=1.04-1.61, P=0.02; AA vs. CA+CC: OR=1.25, 95% CI=1.01-1.55, P=0.04). However, no significant relationship was found between C118T variant and glioma susceptibility.

CONCLUSIONS

Our results indicated that ERCC1 C8092A, not C118T polymorphism might be a biomarker for patients with glioma among Chinese population. Future studies with more ethnicities are needed to explore the precise association.

Association between the XRCC1 Arg194Trp polymorphism and glioma risk: an updated meta-analysis

Gliomas are the most common type of primary brain tumors. The XRCC1 Arg194Trp variant affects the proliferating cell nuclear antigen( PCNA) binding region, which suggests that this mutation may contribute to gliomagenesis and a number of articles have examine the association between XRCC1 Arg194Trp and the susceptibility to glioma. However, the results were conflicting. Test of heterogeneity, sensitivity analysis, meta- analysis, and assessment of publication bias were all performed in our present meta-analysis, covering a total of 5,407 patients and 7,715 healthy persons. In the overall analysis the XRCC1 Arg194Trp polymorphism showed a significant association with glioma susceptibility in a recessive mode l(for TrpTrp vs ArgArg+ArgTrp: OR=1.918, 95%CI=1.575-2.336, I2=2.3%). In addition, analysis of subgroups presented an increased risk in Asians and populations-based on hospitals. The results suggested that the XRCC1 Arg194Trp polymorphism is a genetic risk factor for glioma, especially in Asian population. To further evaluate gene-gene and gene-environment interactions on XRCC1 polymorphisms and glioma risk, thousands of subjects and tissue-specific biochemical characterizations are required.

Mangiferin regulates proliferation and apoptosis in glioma cells by induction of microRNA-15b and inhibition of MMP-9 expression

Mangiferin, a flavonoid extracted from the leaves of the Anacardiaceae plant, the mango tree, has physiological activity and pharmacological effects in many aspects. The present study aimed to clarify the effect of mangiferin on proliferation and apoptosis of glioma cells and the mechanism of these curative effects of mangiferin. In this experiment, we detected the proliferation using 3-(4,5-dimethylthylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay. Then, cell apoptosis of U87 glioma cells was measured with the Annexin V-FITC/propidium iodide (PI) apoptosis detection kit, DAPI staining assay and the caspase-3 and caspase-9 activity assay kit. Next, quantitative real-time PCR and gelatin zymography were used to analyze the expression of microRNA-15b (miR-15b) and matrix metalloproteinase-9 (MMP-9), respectively. MMP-9 agonist, miR-15b mimics and anti-miR-15b mimics were added to the U87 glioma cells for elucidating the mechanisms involved in the curative effects of mangiferin. In the present study, mangiferin notably restrained the proliferation and increased the apoptosis of the U87 glioma cells. Meanwhile, mangiferin specifically promoted the expression of miR-15b and suppressed the level of MMP-9 in the U87 glioma cells. miR-15b regulated the expression of MMP-9 in the U87 glioma cells. MMP-9 agonist and anti-miR‑15b reduced the curative effects of mangiferin in the U87 glioma cells. In summary, mangiferin regulates proliferation and apoptosis in glioma cells by induction of miR-15b and inhibition of MMP-9 expression.

Association of ERCC1 rs3212986 & ERCC2 rs13181 polymorphisms with the risk of glioma

Objective:: Several previous studies have reported the role variant of ERCC1 rs3212986 and ERCC2 rs13181 polymorphisms in the risk of glioma, but the results of these studies are inconsistent. Therefore, we aimed to conduct a meta-analysis to investigate the role of ERCC1 rs3212986 and ERCC2 rs13181 on the risk of glioma.

Methods: A comprehensive research was conducted through the databases of Pubmed, EMBASE and the China National Knowledge Infrastructure (CNKI) platforms until June 1, 2014, including 14 eligible case-control studies.

Results: Our meta-analysis found that ERCC1 rs3212986 AA genotype was significantly associated with increased risk of glioma compared with CC genotype, and the pooled OR (95%CI) was 1.29(1.07-1.55). By subgroup analysis, ERCC1 rs3212986 AA genotype was found to be significantly correlated with increased glioma risk in Chinese population (OR=1.37, 95%CI=1.07, 1.55), Similarly, we found that ERCC2 rs13181 GT and TT genotypes were significantly associated with increased risk of glioma in Chinese population, with ORs(95%CI) of 1.47(1.17-1.85) and 1.50(1.02-2.22). But ERCC1 rs3212986 and ERCC2 rs13181 polymorphisms had no significant association with glioma risk in Caucasian populations. By begg’s funnel plot, we found that no publication bias was existed in this meta-analysis.

Conclusion: Our meta-analysis suggested that ERCC1 rs3212986 and ERCC2 rs13181 polymorphism play an important risk factor for brain tumor development in Chinese population, but no association in Caucasian populations.

Glioma risks associate with genetic polymorphisms of XRCC1 gene in Chinese population

Glioma is the most common type of primary brain tumors in adults. Previous evidence indicates that the X-ray repair cross-complementing group 1 gene (XRCC1) is an important candidate gene which influencing the pathogenesis of glioma. This study aims to assess the potential associations between glioma risks and genetic polymorphisms of XRCC1 gene. A total of 1,286 Chinese Han ethnic subjects consisting of 638 glioma patients and 648 controls were recruited in this case-control study. The genotyping of XRCC1 genetic polymorphisms (c.482C>T, c.1161G>A, and c.1804C>A) were conducted using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), created restriction site-PCR (CRS-PCR) and DNA sequencing methods. Our data indicated that the allelic and genotypic frequencies of these genetic polymorphisms in glioma patients were significantly different from those of controls. We detected that the alleles/genotypes were statistically associated with the increased risks of glioma (for c.482C>T, TT versus (vs.) CC: OR = 2.24, 95% CI = 1.48-3.39, P < 0.001; T vs. C: OR = 1.30, 95% CI = 1.09-1.53, P = 0.003; for c.1161G>A, AA vs. GG: OR = 1.62, 95% CI = 1.11-2.35, P = 0.012; A vs. G: OR = 1.19, 95% CI = 1.01-1.41, P = 0.040; for c.1804C>A, AA vs. CC: OR = 2.12, 95% CI = 1.45-3.11, P < 0.001; A vs. C: OR = 1.32, 95% CI = 1.12-1.56, P = 0.001). Our findings suggest that these genetic polymorphisms of XRCC1 gene may influence glioma risks in Chinese Han ethnic subjects, and might be potential molecular markers for evaluating glioma risks.

XRCC1 gene polymorphisms and glioma risk in Chinese population: a meta-analysis

Background

Three extensively investigated polymorphisms (Arg399Gln, Arg194Trp, and Arg280His) in the X-ray repair cross-complementing group 1 (XRCC1) gene have been implicated in risk for glioma. However, the results from different studies remain inconsistent. To clarify these conflicts, we performed a quantitative synthesis of the evidence to elucidate these associations in the Chinese population.

Methods

Data were extracted from PubMed and EMBASE, with the last search up to August 21, 2014. Meta-analysis was performed by critically reviewing 8 studies for Arg399Gln (3062 cases and 3362 controls), 8 studies for Arg194Trp (3419 cases and 3680 controls), and 5 studies for Arg280His (2234 cases and 2380 controls). All of the statistical analyses were performed using the software program, STATA (version 11.0).

Results

Our analysis suggested that both Arg399Gln and Arg194Trp polymorphisms were significantly associated with increased risk of glioma (for Arg399Gln polymorphism: Gln/Gln vs. Arg/Arg, OR = 1.82, 95% CI = 1.46–2.27, P = 0.000; Arg/Gln vs. Arg/Arg, OR = 1.25, 95% CI = 1.10–1.42, P = 0.001 and for Arg194Trp polymorphism: recessive model, OR = 1.78, 95% CI = 1.44–2.19, P = 0.000), whereas the Arg280His polymorphism had no influence on the susceptibility to glioma in a Chinese population.

Conclusions

This meta-analysis suggests that there may be no association between the Arg280His polymorphism and glioma risk, whereas the Arg399Gln/Arg194Trp polymorphisms may contribute to genetic susceptibility to glioma in the Chinese population. Nevertheless, large-scale, well-designed and population-based studies are needed to further evaluate gene-gene and gene–environment interactions, as well as to measure the combined effects of these XRCC1 variants on glioma risk.

The XRCC3 Thr241Met polymorphism influences glioma risk - a meta-analysis

BACKGROUND

Findings from previous published studies regarding the association of the XRCC3 Thr241Met polymorphism with glioma susceptibility have often been conflicting. Therefore, a meta-analysis including all available publications was carried out to make a more precise estimation of the potential relationship.

METHODS

By searching the electronic databases of Pubmed and Embase (up to April 1st, 2013), a total of nine case-control studies with 3,752 cases and 4,849 controls could be identified for inclusion in the current meta-analysis. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the strength of the association.

RESULTS

This meta-analysis showed the XRCC3 Thr241Met polymorphism to be significantly associated with decreased glioma risk in the allelic model (Met allele vs. Thr allele: OR= 0.708, 95%CI= 0.631-0.795). Moreover, we also observed a statistically significant association between the XRCC3 Thr241Met polymorphism and reduced glioma risk in analyses stratified by ethnicity (Asian) and source of controls (hospital based) in the allelic model.

CONCLUSIONS

Current evidence suggests that the XRCC3 Thr241Met polymorphism may be a risk factor for glioma development, especially in Asians.

Frequency distribution of DNA repair genes ERCC1 and ERCC2 polymorphisms in South Indian healthy population

DNA repair genes are crucial in maintaining the integrity of the whole genome. Single nucleotide polymorphisms (SNPs) in DNA repair genes have been attributed to the development of various cancers. SNPs of DNA repair genes (ERCC1 and ERCC2) have been implicated in the causation of various cancers as well as inter-individual variability in the therapeutic outcomes of platinum based therapy. Thus establishing the frequency of these functional SNPs in the healthy population is of significance. The present study was aimed to establish the allele and genotype frequencies of ERCC1 (19007C>T, rs11615; 8092C>A, rs3212986) and ERCC2 (Asp312Asn, rs1799793) genes in South Indian healthy population and to compare the data from HapMap populations. The study population consisted of 128 healthy South Indian unrelated individuals of either sex aged between 18 and 60 years. Standard phenol-chloroform method was used to extract DNA from peripheral leukocytes. The genotype of DNA repair gene polymorphisms was determined by quantitative real-time polymerase chain reaction using TaqMan genotyping assay. The observed frequency of the studied polymorphisms followed Hardy-Weinberg equilibrium (p>0.05). The frequencies of the minor alleles of the SNPs rs11615 (T), rs3212986 (A) and rs1799793 (A) were 43.8%, 29.3% and 35.6%, respectively. Gender-based analysis showed no significant difference in the frequency pattern. The observed allele and genotype frequencies showed significant ethnic difference between South Indians and other HapMap populations. This is the first study to provide the normative frequency data of allele and genotype distribution of three SNPs of ERCC1 and ERCC2 in South Indian healthy population. It might be useful in future genotype-phenotype association studies, especially for predicting the efficacy and adverse events of platinum based drugs.

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%).

DNA repair gene XRCC3 Thr241Met polymorphism and susceptibility to glioma: A case-control study

The DNA repair gene, X-ray repair cross-complementing group 3 (XRCC3) Thr241Met polymorphism may be associated with a susceptibility to glioma. The present study aimed to investigate the association between the XRCC3 Thr241Met polymorphism and the potential susceptibility to gliomas. A hospital-based case-control study was conducted, which included a total of 886 patients with glioma and 886 healthy control subjects. Peripheral blood samples were extracted and the polymerase chain reaction-restriction fragment length polymorphism method was performed to analyze the genotypes. The glioma patients had a significantly higher frequency of the XRCC3 241 MetMet genotype [odds ratio (OR) = 1.62; 95% confidence interval (CI): 1.09–2.41; P=0.02] compared with the control subjects. When stratified by the grade of the glioma, the patients with stage IV glioma (according to the World Health Organization classification) had a significantly higher frequency of the XRCC3 241 MetMet genotype (OR=1.61; 95% CI: 1.06–2.44; P=0.03). When stratified by the histology of the glioma, there was no significant difference in the distribution of each genotype. The findings of the present study indicate that the XRCC3 Thr241Met polymorphism is associated with a susceptibility to glioma.

Association of ERCC1 C8092A and ERCC2 Lys751Gln polymorphisms with the risk of glioma: a meta-analysis

Objectives

To comprehensively evaluate the association of ERCC1 C8092A and ERCC2 Lys751Gln polymorphisms with the risk of glioma.

Methods

Potential studies were searched and selected through the Pubmed/MEDLINE, EMBASE, the China National Knowledge Infrastructure (CNKI) platforms, WanFang and VIP database up to June 2013. Two investigators independently reviewed full text and included studies met inclusion criteria. Combined odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated in a fixed-effects model or a random-effects model according to results of heterogeneity test. All analyses were performed by Revman 5.2 and Stata 10.0 software.

Results

A total of 10 studies were included in our meta-analysis, including 3,580 glioma patients and 4,728 controls. Overall, ERCC1 C8092A polymorphism was associated with the risk of glioma (AA vs. CC: OR = 1.29, 95%CI: 1.07–1.55, P = 0.01; recessive model: OR = 1.29; 95% CI: 1.07–1.55, P = 0.01). When stratified by ethnicity, significant association was only observed in the Chinese population (AA vs. CC: OR = 1.37, 95%CI: 1.03–1.81, P = 0.03; recessive model: OR = 1.34; 95% CI: 1.02–1.75, P = 0.04). For ERCC2 Lys751Gln polymorphism, no significant association was found between ERCC2 Lys751Gln polymorphism and the risk of glioma in different genetic models. A significant association of ERCC2 Lys751Gln polymorphism with the risk of glioma was identified in the Caucasian population under recessive model (OR = 0.87; 95% CI: 0.78–0.98, P = 0.02), but not in the Chinese population.

Conclusion

This meta-analysis suggested that the AA genotype of ERCC1 C8092A polymorphism might increase the susceptibility of glioma in the Chinese population. And the TT genotype of ERCC2 Lys751Gln polymorphism may decrease the risk of glioma in the Caucasian population. But the small number of studies and moderate methodological quality require cautious interpretation of the study results.

Association of XRCC3 Thr241Met polymorphisms and gliomas risk: evidence from a meta-analysis

The relationship between the X-ray repair cross-complementing group 3 (XRCC3) Thr241Met polymorphism and gliomas remains inclusive or controversial. For better understanding of the effect of XRCC3 Thr241Met polymorphism on glioma risk, a meta-analysis was performed. All eligible studies were identified through a search of PubMed, Elsevier Science Direct, Excerpta Medica Database (Embase) and Chinese Biomedical Literature Database (CBM) before May 2013. The association between the XRCC3 Thr241Met polymorphism and gliomas risk was conducted by odds ratios (ORs) and 95% confidence intervals (95% CIs). A total of nine case-control studies including 3,533 cases and 4,696 controls were eventually collected. Overall, we found that XRCC3 Thr241Met polymorphism was significantly associated with the risk of gliomas (T vs. C: OR=1.10, 95%CI=1.01-1.20, P=0.034; TT vs. CC: OR=1.30, 95%CI=1.03-1.65, P=0.027; TT vs.

TC/CC

OR=1.29, 95%CI=1.01-1.64, P=0.039). In the subgroup analysis based on ethnicity, the significant association was found in Asian under four models (T vs. C: OR=1.17, 95%CI=1.07-1.28, P=0.00; TT vs. CC: OR=1.79, 95%CI=1.36- 2.36, P=0.00; TT vs.

TC/CC

OR=1.75, 95%CI=1.32-2.32, P=0.00; TT/TC vs. CC: OR=1.11,95% CI=1.02-1.20). This meta-analysis suggested that the XRCC3 Thr241Met polymorphism is a risk factor for gliomas, especially for Asians. Considering the limited sample size and ethnicities included in the meta-analysis, further large scale and well-designed studies are needed to confirm our results.

DNA repair gene ERCC1 polymorphisms may contribute to the risk of glioma

Polymorphisms in excision repair cross-complementing rodent repair deficiency complementation group 1 (ERCC1) gene have been shown to affect individual susceptibility to glioma, though studies have yielded conflicting results. This meta-analysis aims to derive a more precise estimation of the association between ERCC1 C8092A and C118T polymorphisms and glioma risk. A literature search of PubMed, Embase, Web of Science, Cochrane Library, and CBM databases was conducted to identify all eligible studies published before August 5, 2013. Crude odds ratios (ORs) with their corresponding confidence intervals (95% CIs) were used to assess the strength of this association. A meta-analysis was performed by reviewing seven studies on the C8092A polymorphism (2,978 cases and 4,051 controls) and four studies on the C118T polymorphism (1,390 Asian cases and 1,546 Asian controls). Pooled analysis yielded a significant association between the C8092A variant genotype and increased risk of glioma. As for ethnicity, the A allele was associated with increased risk of glioma in Asians, while no similar finding was observed in Caucasians. Stratified analyses by histological subtype indicated that the C8092A polymorphism showed a significant association with the risk of non-glioblastoma multiforme. For the C118T polymorphism, increased glioma susceptibility was also observed among Asians. Taken together, results from our meta-analysis support the view that common variants in ERCC1 may contribute to susceptibility to glioma, especially in Asians. However, further studies investigating the significance of these two polymorphisms as markers of susceptibility to and disease progression of glioma are still needed.

Quantitative assessment of the association between XRCC3 C18607T polymorphism and glioma risk

XRCC3 has an important function in the DNA double-strand break, and XRCC3 C18607T polymorphism is a common polymorphism at exon 7 of the XRCC3 gene. Published data on the association between XRCC3 C18607T polymorphism and glioma risk were inconclusive. Electronic databases of PubMed, and Embase were searched for studies assessing the association between XRCC3 C18607T polymorphism and glioma risk. Pooled odds ratio (OR) and 95 % confidence interval (95 % CI) were calculated to estimate the association. Ten studies with five studies from Caucasians and five studies from Asians were included, including 9,369 subjects. Meta-analysis of total included studies showed that XRCC3 C18607T polymorphism was associated with increased risk of glioma (T vs. C: OR = 1.14, 95 % CI 1.02-1.28, P = 0.02; TT vs. CC: OR = 1.37, 95 % CI 1.03-1.83, P = 0.03; TT vs.

CC/CT

OR = 1.31, 95 % CI 1.00-1.71, P = 0.05; TT/CT vs. CC: OR = 1.12, 95 % CI 1.02-1.22, P = 0.02). Meta-analysis of the five studies from Asians showed that XRCC3 C18607T polymorphism was associated with increased risk of glioma (T vs. C: OR = 1.22, 95% CI 1.09-1.36, P < 0.01; TT vs. CC: OR = 1.89, 95 % CI 1.38-2.57, P < 0.01; TT vs.

CC/CT

OR = 1.78, 95 % CI 1.31-2.40, P < 0.01; TT/CT vs. CC: OR = 1.19, 95 % CI 1.04-1.36, P = 0.01). Meta-analysis of the five studies from Caucasians didn't find the association. In conclusion, the finding from the meta-analysis provides strong evidence for the association between XRCC3 C18607T polymorphism and glioma risk.

Association between XRCC3 Thr241Met polymorphism and risk of brain tumors: a meta-analysis

X-ray repair cross-complementing group 3 (XRCC3) plays an important role in the process of homologous recombination repair for DNA double-strand breaks which further maintains the stability of the genome. XRCC3 Thr241Met polymorphism has been indicated in the development of cancers, but the association of the XRCC3 Thr241Met polymorphism with risk of brain tumors is still unclear owing to the conflicting findings from previous studies. We performed a meta-analysis to provide a better understanding on the association between the XRCC3 Thr241Met polymorphism and risk of brain tumors. The pooled odds ratio (OR) with corresponding 95 % confidence interval (95 % CI) was used to assess the association. Thirteen case-control studies involving a total of 4,984 cases and 7,472 controls were included. Overall, there was no statistically significant association between the XRCC3 Thr241Met polymorphism and risk of brain tumors under all contrast models. Subgroup analysis by race suggested that the XRCC3 Thr241Met polymorphism was associated with increased risk of brain tumors in Asians under all four contrast models (Met vs. Thr: OR = 1.22, 95 % CI 1.09-1.36, P < 0.01; MetMet vs. ThrThr: OR = 1.89, 95 % CI 1.38-2.57, P < 0.01; MetMet vs. ThrThr/ThrMet: OR = 1.78, 95 % CI 1.31-2.40, P < 0.01; and MetMet vs. ThrThr/ThrMet: OR = 1.19, 95 % CI 1.04-1.36, P = 0.01). However, there was no significant association between the XRCC3 Thr241Met polymorphism and risk of brain tumors in Caucasians. Therefore, the XRCC3 Thr241Met polymorphism is associated with increased risk of brain tumors, especially in Asians.

Association between the Thr241Met polymorphism of X-ray repair cross-complementing group 3 gene and glioma risk: evidence from a meta-analysis based on 4,136 cases and 5,233 controls

Genetic polymorphism of X-ray repair cross-complementing group 3 (XRCC3) Thr241Met has been implicated to alter the risk of glioma, but the results are controversial. Medline, PubMed, Embase, and Cochrane Library databases were independently searched by two investigators up to 13 July 2013. Summary odds ratios (OR) and 95% confidence interval (CI) for Thr241Met polymorphism and prostate cancer were calculated. Statistical analysis was performed with the software program Stata 12.0. A total of 10 independent studies, including 4,136 cases and 5,233 controls, were identified. Our analysis suggested that Thr241Met was not associated with glioma risk in overall population. In the subgroup analysis, we detected no significant association between Thr241Met polymorphism and glioma risk in different descent populations. Subgroup analysis was held by source of controls, significant association was found between this polymorphism and glioma risk for population-based studies (homozygote model: OR = 1.747, 95% CI = 1.123-2.717, Ph = 0.059, I(2) = 59.7%; recessive model, OR = 1.455, 95% CI = 1.179-1.795, Ph = 0.111, I(2) = 50.1%; allele model, OR = 1.258, 95% CI = 1.010-1.566, Ph = 0.011, I(2) = 72.9%). This meta-analysis showed the evidence that XRCC3 Thr241Met polymorphism was associated with a low risk of glioma development.

Genetic polymorphisms in XRCC1 gene and susceptibility to glioma in Chinese Han population

Glioma is the most common type of primary brain malignancy in adults. The X-ray repair cross-complementing group 1 (XRCC1) is an important candidate gene for influencing the pathogenesis of glioma. This study aimed to evaluate the potential association between XRCC1 genetic polymorphisms and glioma susceptibility. This case-control study was conducted in Chinese Han populations consisting of 620 glioma cases and 630 cancer-free controls. XRCC1 genetic polymorphisms were detected by the polymerase chain reaction-restriction fragment length polymorphism and verified using DNA sequencing methods. The c.910A>G and c.1779C>G genetic polymorphisms were identified in this study. Our data suggested that the genotypes/alleles of these two genetic polymorphisms were statistically associated with the increased risk of glioma. As for c.910A>G, the risk of glioma for genotype GG was significantly higher than wild genotype AA (odds ratio (OR) = 1.98, 95% confidence interval (CI) 1.33-2.94, P = 0.001). As for c.1779C>G, the genotype GG was statistically associated with the increased risk of glioma compared to wild genotype CC (OR = 1.80, 95% CI 1.17-2.78, P = 0.007). Both of alleles G in c.910A>G and c.1779C>G may contribute to glioma susceptibility (G versus (vs.) A, OR = 1.30, 95% CI 1.09-1.54, P = 0.003; G vs. C, OR = 1.19, 95% CI 1.00-1.42, P = 0.045). Our findings indicate that the c.910A>G and c.1779C>G genetic polymorphisms are associated with the susceptibility to glioma in Chinese Han populations and might be used as molecular markers for evaluating glioma risk.

DNA repair gene XRCC3 Thr241Met polymorphism and glioma risk: a meta-analysis

BACKGROUND

The polymorphism of XRCC3 Thr241Met has been indicated to be correlated with glioma susceptibility, but study results are still debatable. The present meta-analysis was performed to investigate the association between XRCC3 Thr241Met polymorphism and glioma.

METHODS

A total of 3754 glioma patients and 4849 controls from nine separate studies were involved. The pooled odds ratio (OR) and its corresponding 95% confidence interval (CI) was assessed by the random-effects model.

RESULTS

The association between XRCC3 Thr241Met polymorphism and glioma was significant in the recessive model (OR = 1.36; 95% CI, 1.02 - 1.82; P = 0.03). In a stratified analysis by the ethnicity, significantly increased risk was detected in Asians (OR = 1.93; 95% CI, 1.18 - 3.17; P = 0.009).

CONCLUSIONS

In conclusion, XRCC3 Thr241Met polymorphism was implied to be associated with increased glioma risk. More studies are needed to validate this result.