Association between the XRCC3 T241M polymorphism and risk of cancer: evidence from 157 case-control studies

Genetic Polymorphisms Involved in Bladder Cancer: A Global Review

Bladder cancer (BC) has been associated with genetic susceptibility. Single peptide polymorphisms (SNPs) can modulate BC susceptibility. A literature search was performed covering the period between January 2000 and October 2020. Overall, 334 articles were selected, reporting 455 SNPs located in 244 genes. The selected 455 SNPs were further investigated. All SNPs that were associated with smoking and environmental exposure were excluded from this study. A total of 197 genes and 343 SNPs were found to be associated with BC, among which 177 genes and 291 SNPs had congruent results across all available studies. These genes and SNPs were classified into eight different categories according to their function.

The effects of DNA repair polymorphisms on chromosome aberrations in the population of Kazakhstan

Purpose: To analyze the effects of DNA repair polymorphism and other factors on the frequency chromosome aberrations in an irradiated cohort of subjects living around the Semipalatinsk nuclear test site and non-exposed group of subjects from ecologically favorable zones of Kazakhstan.Materials and methods: Blood samples were collected in the rural areas of the East Kazakhstan district around the Semipalatinsk nuclear test site and ecologically favorable zones of Almaty region of Kazakhstan. Chromosome aberrations in the fresh and cryopreserved peripheral blood lymphocyte cultures were analyzed by Giemsa staining. Single nucleotide polymorphisms at eight DNA repair genes (XRCC1 rs1799782, XRCC1 rs25487, XRCC3 rs861539, ATM rs1801516, XPD rs1799793, XPD rs13181, APEX1 rs1130409, and hOGG1 rs1052133) were determined by PCR-RFLP method.Results: The age of donors and smoking significantly affected the frequency of chromosome aberrations among the irradiated and control subjects. In the irradiated and control cohorts, the frequency of chromosome aberrations was significantly increased in the heterozygous ATM rs1801516 (1853 Asp/Asn) individuals; for the rest of the loci no significant associations between polymorphism and the frequency of chromosome aberrations were detected.Conclusions: The age of donors, smoking, and the ATM rs1801516 polymorphism significantly affect the frequency of chromosome aberrations among individuals inhabiting contaminated area around the Semipalatinsk nuclear weapon test site, as well as among those inhabiting ecologically favorable zones of Kazakhstan.

Rad51 paralogs and the risk of unselected breast cancer: A case-control study

A case-control study was conducted in which we evaluated the association between genetic variability of DNA repair proteins belonging to the Rad51 family and breast cancer (BrC) risk. In the study, 132 female BrC cases and 189 healthy control females were genotyped for a total of 14 common single nucleotide polymorphisms (SNPs) within Rad51 and Xrcc3. Moreover, our previously reported Rad51C genetic data were involved to explore the nonlinear interactions among SNPs within the three genes and effect of such interactions on BrC risk. The rare rs5030789 genotype (-4601AA) in Rad51 was found to significantly decrease the BrC risk (OR = 0.5, 95% CI: 0.3-1.0, p<0.05). An interaction between this SNP, rs2619679 and rs2928140 (both in Rad51), was found to result in a two three-locus genotypes -4719AA/-4601AA/2972CG and -4719AT/-4601GA/2972CC, both of which were found to increase the risk of BrC (OR = 8.4, 95% CI: 1.8-38.6, p<0.0001), instead. Furthermore, rare Rad51 rs1801320 (135CC) and heterozygous Xrcc3 rs3212057 (10343GA) genotypes were found to respectively increase (OR = 10.6, 95% CI: 1.9-198, p<0.02) and decrease (OR = 0.0, 95% CI: 0.0-NA, p<0.05) the risk of BrC. Associations between these SNPs and BrC risk were further supported by outcomes of employed machine learning analyses. In Xrcc3, the 4541A/9685A haplotype was found to be significantly associated with reduced BrC risk (OR = 0.5; 95% CI: 0.3-0.9; p<0.05). Concluding, our study indicates a complex role of SNPs within Rad51 (especially rs5030789) and Xrcc3 in BrC, although their significance with respect to the disease needs to be further clarified.

Thyroid Cancer: The Quest for Genetic Susceptibility Involving DNA Repair Genes

The incidence of thyroid cancer (TC), particularly well-differentiated forms (DTC), has been rising and remains the highest among endocrine malignancies. Although ionizing radiation (IR) is well established on DTC aetiology, other environmental and genetic factors may also be involved. DNA repair single nucleotide polymorphisms (SNPs) could be among the former, helping in explaining the high incidence. To further clarify the role of DNA repair SNPs in DTC susceptibility, we analyzed 36 SNPs in 27 DNA repair genes in a population of 106 DTCs and corresponding controls with the aim of interpreting joint data from previously studied isolated SNPs in DNA repair genes. Significant associations with DTC susceptibility were observed for XRCC3 rs861539, XPC rs2228001, CCNH rs2230641, MSH6 rs1042821 and ERCC5 rs2227869 and for a haplotype block on chromosome 5q. From 595 SNP-SNP combinations tested and 114 showing relevance, 15 significant SNP combinations (p < 0.01) were detected on paired SNP analysis, most of which involving CCNH rs2230641 and mismatch repair variants. Overall, a gene-dosage effect between the number of risk genotypes and DTC predisposition was observed. In spite of the volume of data presented, new studies are sought to provide an interpretability of the role of SNPs in DNA repair genes and their combinations in DTC susceptibility.

Associations between XRCC3 Thr241Met polymorphisms and breast cancer risk: systematic-review and meta-analysis of 55 case-control studies

BACKGROUND

The X-ray repair cross-complementing group 3 (XRCC3) is an efficient component of homologous recombination and is required for the preservation of chromosomal integrity in mammalian cells. The association between Thr241Met single-nucleotide polymorphism (SNP) in this gene and susceptibility to breast cancer has been assessed in several studies. Yet, reports are controversial. The present meta-analysis has been designed to identify whether this SNP is associated with susceptibility to breast cancer.

METHODS

We performed a systematic review and meta-analysis for retrieving the case-control studies on the associations between T241 M SNP and the risk of breast cancer. Crude odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to verify the association in dominant, recessive, and homozygote inheritance models.

RESULTS

We included 55 studies containing 30,966 sporadic breast cancer cases, 1174 familial breast cancer cases and 32,890 controls in the meta-analysis. In crude analyses, no association was detected between the mentioned SNP and breast cancer risk in recessive, homozygote or dominant models. However, ethnic based analysis showed that in sporadic breast cancer, the SNP was associated with breast cancer risk in Arab populations in homozygous (OR (95% CI) = 3.649 (2.029-6.563), p = 0.0001) and recessive models (OR (95% CI) = 4.092 (1.806-9.271), p = 0.001). The association was significant in Asian population in dominant model (OR (95% CI) = 1.296, p = 0.029). However, the associations was significant in familial breast cancer in mixed ethnic-based subgroup in homozygote and recessive models (OR (95% CI) = 0.451 (0.309-0.659), p = 0.0001, OR (95% CI) = 0.462 (0.298-0.716), p = 0.001 respectively).

CONCLUSIONS

Taken together, our results in a large sample of both sporadic and familial cases of breast cancer showed insignificant role of Thr241Met in the pathogenesis of this type of malignancy. Such results were more conclusive in sporadic cases. In familial cases, future studies are needed to verify our results.

Investigation of polymorphisms in genes involved in estrogen metabolism in menstrual migraine

Migraine is a common, disabling headache disorder, which is influenced by multiple genes and environmental triggers. After puberty, the prevalence of migraine in women is three times higher than in men and >50% of females suffering from migraine report a menstrual association, suggesting hormonal fluctuations can influence the risk of migraine attacks. It has been hypothesized that the drop in estrogen during menses is an important trigger for menstrual migraine. Catechol-O-methyltransferase (COMT) and Cytochrome P450 (CYP) enzymes are involved in estrogen synthesis and metabolism. Functional polymorphisms in these genes can influence estrogen levels and therefore may be associated with risk of menstrual migraine. In this study we investigated four single nucleotide polymorphisms in three genes involved in estrogen metabolism that have been reported to impact enzyme levels or function, in a specific menstrual migraine cohort. 268 menstrual migraine cases and 142 controls were genotyped for rs4680 in COMT (Val158Met), rs4646903 and rs1048943 in CYP1A1 (T3801C and Ile462Val) and rs700519 in CYP19A1 (Cys264Arg). Neither genotype nor allele frequencies for the COMT and CYP SNPs genotyped were found to be significantly different between menstrual migraineurs and controls by chi-square analysis (P>0.05). Therefore we did not find association of functional polymorphisms in the estrogen metabolism genes COMT, CYP1A1 or CYP19A1 with menstrual migraine. Further studies are required to assess whether menstrual migraine is genetically distinct from the common migraine subtypes and identify genes that influence risk.

Quantitative assessment of the influence of X-ray repair cross-complementing group 3 rs861539 polymorphism and cutaneous melanoma susceptibility

Previous studies evaluating the association between X-ray repair cross-complementing group 3 (XRCC3) rs861539 polymorphism and cutaneous melanoma susceptibility reported conflicting findings. To draw a more precise association between XRCC3 rs861539 polymorphism and cutaneous melanoma susceptibility, we searched PubMed, EMBASE and Web of Science for case-control studies. A total of eight case-control studies including 3463 cases of melanoma and 4216 controls were included in the meta-analysis. Overall, no significant associations were found between XRCC3 rs861539 polymorphism and cutaneous melanoma susceptibility under all four genetic models (TT vs CC: OR 0.99, 95 % CI 0.86-1.14; TC vs CC: OR 0.92, 95 % CI 0.83-1.01; dominant model: OR 0.94, 95 % CI 0.85-1.03; recessive model: OR 1.05, 95 % CI 0.92-1.19). In the subgroup by source of control, no significant associations were found in hospital-based and population-based subgroup. This meta-analysis suggested that the XRCC3 rs861539 polymorphism was not a risk factor for cutaneous melanoma susceptibility.

XRCC3 is a promising target to improve the radiotherapy effect of esophageal squamous cell carcinoma

Radiotherapy is widely applied for treatment of esophageal squamous cell carcinoma (ESCC). The Rad51-related protein XRCC3 plays roles in the recombinational repair of DNA double-strand breaks to maintain chromosome stability and repair DNA damage. The present study aimed to investigate the effect of XRCC3 on the radiotherapy response of ESCC and the underlying mechanisms of the roles of XRCC3 in ESCC radiosensitivity. XRCC3 expression in ESCC cells and tissues was higher than that in normal esophageal epithelial cells and corresponding adjacent noncancerous esophageal tissue. High XRCC3 expression was positively correlated with resistance to chemoradiotherapy in ESCC and an independent predictor for short disease-specific survival of ESCC patients. Furthermore, the therapeutic efficacy of radiotherapy in vitro and in vivo was substantially increased by knockdown of XRCC3 in ESCC cells. Ectopic overexpression of XRCC3 in both XRCC3-silenced ESCC cells dramatically enhanced ESCC cells' resistance to radiotherapy. Moreover, radiation resistance conferred by XRCC3 was attributed to enhancement of homologous recombination, maintenance of telomere stability, and a reduction of ESCC cell death by radiation-induced apoptosis and mitotic catastrophe. Our data suggest that XRCC3 protects ESCC cells from ionizing radiation-induced death by promoting DNA damage repair and/or enhancing telomere stability. XRCC3 may be a novel radiosensitivity predictor and promising therapeutic target for ESCC.

Association between the XRCC3 Thr241Met polymorphism and breast cancer risk: an updated meta-analysis of 36 case-control studies

BACKGROUND

The X-ray repair cross-complementing group 3 (XRCC3) is a highly suspected candidate gene for cancer susceptibility. Attention has been drawn upon associations of the XRCC3 Thr241Met polymorphism with breast cancer risk. However, the previous published findings remain controversial. Hence, we performed a meta-analysis to accurately evaluate any association between breast cancer and XRCC3 T241M (23, 812 cases and 25, 349 controls) in different inheritance models.

MATERIALS AND METHODS

PubMed and Web of Science databases were searched systematically until December 31, 2013 to obtain all the records evaluating the association between the XRCC3 Thr241Met polymorphism and breast cancer risk. Crude odds ratios (ORs) together with 95% confidence intervals (CIs) were used to assess the strength of associations.

RESULTS

When all eligible studies were pooled into the meta analysis of XRCC3 T241M polymorphism, a significantly increased breast cancer risk was observed in heterozygote comparison (OR=1.06, 95%CI=1.01-1.12). No significant associations were found in other models. In subgroup analysis, this polymorphism seemed to be associated with elevated breast risk in Asians. No publication bias was detected.

CONCLUSIONS

This meta-analysis suggests that the T241M polymorphism confers a weakly increased breast cancer risk. A study with the larger sample size is needed to further evaluate gene-gene and gene-environment interactions of the XRCC3 T241M polymorphism with breast cancer risk.

Association between the XRCC3 Thr241Met polymorphism and risk of colorectal cancer: a meta analysis of 5,193 cases and 6,645 controls

BACKGROUND

Many studies have reported associations of the X-ray repair cross-complementing group 3 (XRCC3) Thr241Met polymorphism with colorectal cancer (CRC) risk, but the results remained controversial. Hence, we performed the present meta-analysis with different inheritance models.

MATERIALS AND METHODS

We searched the PubMed and Google scholar databases for studies relating to associations between XRCC3 Thr241Met polymorphism and risk of CRC. 16 studies with 5,193 cases and 6,645 controls were finally included into the meta-analysis.

RESULTS

We found that the XRCC3 Thr241Met polymorphism was associated with increased CRC risk only under a dominant genetic model (CC+CT vs. TT: OR 0.575, 95%CI 0.498-1.665, p<0.001, Pheterogeneity=0.00, I2=83%). There was a significant association between XRCC3 Thr241Met polymorphism and CRC risk in Caucasian in the overall 8 studies under only in the heterozygote genetic model (CT vs. TT: OR=0.929, 95%CI=0.806-1.070, P=0.308, Pheterogeneity=0.002, I2=57%). Four studies evaluated the XRCC3 Thr241Met polymorphism and CRC risk in Asians. Two genetic models of the XRCC3 polymorphism were significantly correlated with increasing risk in Asians (dominant model: CC+CT vs. TT: OR= 0.609, 95%CI=411-0.902, P=0.013, Pheterogeneity=0.54, I2=0.00%; Allele model: C vs. T: OR=0.708, 95 %=CI 0.605-0.829, p=0.000, Pheterogeneity=0.000, I2=92%). The sensitivity analysis suggested stability of this meta-analysis and no publication bias was detected.

CONCLUSIONS

In conclusion, this meta-analysis indicates that XRCC3 Thr241Met shows an increased CRC risk, particularly in Asians rather than Caucasians.

Homologous Recombination Repair Polymorphisms and the Risk for Osteosarcoma

Background

DNA repair mechanisms are essential for maintaining genome stability, and genetic variability in DNA repair genes may contribute to cancer susceptibility. Our aim was to evaluate the influence of polymorphisms in the homologous recombination repair genes XRCC3, RAD51, and NBN on the risk for osteosarcoma.

Methods

In total, 79 osteosarcoma cases and 373 controls were genotyped for eight single nucleotide polymorphisms (SNPs) in XRCC3, RAD51, and NBN. Logistic regression was used to determine the association of these SNPs with risk for osteosarcoma.

Results

None of the investigated SNPs was associated with risk for osteosarcoma in the whole cohort of patients, however, in patients diagnosed before the age of thirty years XRCC3 rs861539 C>T and NBN rs1805794 G>C were associated with significantly decreased risk for osteosarcoma (P=0.047, OR=0.54, 95% CI=0.30–0.99 and P=0.036, OR=0.42, 95% CI=0.19–0.94, respectively). Moreover, in the carriers of a combination of polymorphic alleles in both SNPs risk for osteosarcoma was decreased even more significantly (P_trend=0.007). The risk for developing osteosarcoma was the lowest in patients with no wild-type alleles for both SNPs (P=0.039, OR=0.31, 95% CI=0.10–0.94).

Conclusions

Our results suggest that polymorphisms in homologous recombination repair genes might contribute to risk for osteosarcoma in patients diagnosed below the age of thirty years.

The association of CD28 polymorphism, rs3116496, with Cancer: A meta-analysis

OBJECTIVE

To determine the relationship between CD28 polymorphisms, rs3116496, and cancer.

DESIGN

Meta-analysis.

METHODS

PubMed, EMBASE, Web of Science, and Cochrane library databases were searched to identify studies reporting the association between CD28 polymorphism and cancer. Two authors selected identified studies, extracted, and analyzed the data independently.

RESULTS

Individuals carrying a T allele (TT homozygotes and TT+TC heterozygotes) at rs3116496 had a lower incidence of cancer than carriers of a C allele. Subgroup analysis showed that this association held true for Asians, but not Europeans.

CONCLUSION

CD28 polymorphism, rs3116496, contributes to cancer susceptibility in the case of multiple cancers.

Current evidences on the XPG Asp1104His polymorphism and melanoma susceptibility: a meta-analysis based on case-control studies

Previous studies evaluating the association between the XPG Asp1104His polymorphism and melanoma susceptibility remained controversial. To draw a more precise estimation of the relationship, a total of eight published case-control studies containing 5,212 cases and 7,045 controls were included for meta-analysis. Overall, a significant association was found between the XPG Asp1104His polymorphism and melanoma susceptibility for the dominant model (OR = 2.42, 95 % CI = 2.26-2.60). In subgroup analysis by source of control, there was an obvious association was found among Population-based subgroup for the dominant model CC+GC vs GG (OR 2.51, 95 % CI 2.28-2.77), among the Hospital-based subgroup, an obvious association was also found for the dominant model CC+GC vs GG (OR 2.34, 95 % CI 2.12-2.58). This meta-analysis suggested that the XPG Asp1104His polymorphism was a risk factor for melanoma susceptibility.

Polymorphisms in DNA repair genes, hair dye use, and the risk of non-Hodgkin lymphoma

PURPOSE

Genetic polymorphisms in DNA repair genes and hair dye use may both have a role in the development of non-Hodgkin lymphoma (NHL). We aimed to examine the interaction between variants in DNA repair genes and hair dye use with risk of NHL in a population-based case-control study of Connecticut women.

METHODS

We examined 24 single nucleotide polymorphisms in 16 DNA repair genes among 518 NHL cases and 597 controls and evaluated the associations between hair dye use and risk of overall NHL and common NHL subtypes, stratified by genotype, using unconditional logistic regression.

RESULTS

Women who used hair dye before 1980 had a significantly increased risk of NHL, particularly for the follicular lymphoma (FL) subtype, but not for diffuse large B-cell lymphoma. The following genotypes in combination with hair dye use before 1980 were associated with FL risk: BRCA2 rs144848 AC+CC [odds ratio (OR) (95% confidence interval (CI)) 3.28(1.27-8.50)], WRN rs1346044 TT [OR(95% CI) 2.70(1.30-5.65)], XRCC3 rs861539 CT+TT [OR(95% CI) 2.76(1.32-5.77)], XRCC4 rs1805377 GG [OR(95% CI) 2.07(1.10-3.90)] and rs1056503 TT [OR(95% CI) 2.17(1.16-4.07)], ERCC1 rs3212961 CC [OR(95% CI) 1.93(1.00-3.72)], RAD23B rs1805329 CC [OR(95% CI) 2.28(1.12-4.64)], and MGMT rs12917 CC, rs2308321 AA, and rs2308327 AA genotypes [OR(95% CI) 1.96(1.06-3.63), 2.02(1.09-3.75), and 2.23(1.16-4.29), respectively]. In addition, a significant interaction with risk of overall NHL was observed between WRN rs1346044 and hair dye use before 1980 (p(interaction) = 0.032).

CONCLUSIONS

Our results indicated that genetic variation in DNA repair genes modifies susceptibility to NHL in relation to hair dye use, particularly for the FL subtype and in women who began using hair dye before 1980. Further studies are needed to confirm these observations.

Analyzing association of the XRCC3 gene polymorphism with ovarian cancer risk

This meta-analysis aims to examine whether the XRCC3 polymorphisms are associated with ovarian cancer risk. Eligible case-control studies were identified through search in PubMed. Pooled odds ratios (ORs) were appropriately derived from fixed effects models. We therefore performed a meta-analysis of 5,302 ovarian cancer cases and 8,075 controls from 4 published articles and 8 case-control studies for 3 SNPs of XRCC3. No statistically significant associations between XRCC3 rs861539 polymorphisms and ovarian cancer risk were observed in any genetic models. For XRCC3 rs1799794 polymorphisms, we observed a statistically significant correlation with ovarian cancer risk using the homozygote comparison (T2T2 versus T1T1: OR = 0.70, 95% CI = 0.54–0.90, P = 0.005), heterozygote comparison (T1T2 versus T1T1: OR = 1.10, 95% CI = 1.00–1.21, P = 0.04), and the recessive genetic model (T2T2 versus T1T1+T1T2: OR = 0.67, 95% CI = 0.52–0.87, P = 0.002). For XRCC3 rs1799796 polymorphisms, we also observed a statistically significant correlation with ovarian cancer risk using the heterozygote comparison (T1T2 versus T1T1: OR = 0.91, 95% CI = 0.83–0.99, P = 0.04). In conclusion, this meta-analysis shows that the XRCC3 were associated with ovarian cancer risk overall for Caucasians. Asian and African populations should be further studied.

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.

XRCC3 C18067T polymorphism contributes a decreased risk to both basal cell carcinoma and squamous cell carcinoma: evidence from a meta-analysis

Background

The X-ray repair cross-complementing group 3 (XRCC3) in homologous recombination repair (HRR) pathway plays a very important role in DNA double-strand break repair (DSBR). Variations in the XRCC3 gene might lead to altered protein structure or function which may change DSBR efficiency and result in cancer. The XRCC3 C18067T polymorphism has been reported to be associated with skin cancer susceptibility, yet the results of these previous results have been inconsistent or controversial. To derive a more precise estimation of the association, we conducted a meta-analysis.

Methods

The quality of the studies was assessed according to a predefined scale. The association between the XRCC3 C18067T polymorphism and skin cancer risk was assessed by odds ratios (ORs) together with their 95% confidence intervals (CIs).

Results

Overall, no significant association was observed between XRCC3 C18067T polymorphism and skin cancer risk in any genetic model. Stratified analyses according to tumor type, significant association was found in the relationship between XRCC3 C18067T polymorphism and nonmelanoma skin cancer risk (homozygote comparison TT versus CC: OR = 0.74, 95%CI = 0.61–0.90, P = 0.003; recessive model TT versus TC/CC: OR = 0.81, 95%CI = 0.68–0.95, P = 0.01). Furthermore, significant association was also observed in XRCC3 C18067T polymorphism with both basal cell carcinoma risk (homozygote comparison TT versus CC: OR = 0.70, 95%CI = 0.53–0.92, P = 0.011; recessive model TT versus. TC/CC: OR = 0.74, 95%CI = 0.60–0.92, P = 0.007) and squamous cell carcinoma risk (heterozygote comparison TT versus .CC: OR = 0.81, 95%CI = 0.67–0.99, P = 0.04; dominant model TT/TC versus .CC: OR = 0.81, 95%CI = 0.68–0.98, P = 0.029).

Conclusion

The present meta-analysis demonstrates that XRCC3 C18067T polymorphism was not associated with risk of cutaneous melanoma but contributed a decreased risk to both basal cell carcinoma and squamous cell carcinoma.

Gene polymorphisms and chronic obstructive pulmonary disease

The genetic component was suggested to contribute to the development of chronic obstructive pulmonary disease (COPD), a major and growing public health burden. The present review aims to characterize the evidence that gene polymorphisms contribute to the aetiology of COPD and related traits, and explore the potential relationship between certain gene polymorphisms and COPD susceptibility, severity, lung function, phenotypes, or drug effects, even though limited results from related studies lacked consistency. Most of these studies were association studies, rather than confirmatory studies. More large-sized and strictly controlled studies are needed to prove the relationship between gene polymorphisms and the reviewed traits. More importantly, prospective confirmatory studies beyond initial association studies will be necessary to evaluate true relationships between gene polymorphisms and COPD and help individualized treatment for patients with COPD.

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.

Significant association between XRCC3 C241T polymorphism and increased risk of hepatocellular carcinoma: a meta-analysis

Many studies were published to examine the association between XRCC3 C241T polymorphism and hepatocellular carcinoma risk, but their results were inconsistent. To assess the association between XRCC3 C241T polymorphism and hepatocellular carcinoma risk more precisely, a meta-analysis was performed. PubMed, Embase and Wanfang databases were searched for relevant case-control studies. Data were extracted, and the pooled odds ratios (OR) with 95 % confidence intervals (95% CI) were calculated. Finally, seven studies comprising 2,288 cases with hepatocellular carcinoma and 3,249 controls were included into the meta-analysis. Overall, there was an obvious association between XRCC3 C241T polymorphism and increased risk of hepatocellular carcinoma (TT versus CC: OR = 3.31, 95% CI 1.52-7.19, P = 0.003; TT versus

CC/CT

OR = 3.31, 95% CI 1.81-6.06, P < 0.001). After adjusting for heterogeneity, there was still an obvious association between XRCC3 C241T polymorphism and increased risk of hepatocellular carcinoma (TT versus CC: OR = 1.92, 95 % CI 1.13-3.26, P = 0.016; TT versus

CC/CT

OR = 2.10, 95% CI 1.25-3.55, P = 0.005). Overall, there is a significant association between XRCC3 C241T polymorphism and increased risk of hepatocellular carcinoma. Further studies are needed to further assess the association in Caucasians.