• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.8
• /
• pp.3637-3643
• /
• 2012

Objective: Non-homologous end joining (NHEJ) is a pathway for repairing DNA double-strand breaks. Recent publications indicated that XRCC5, XRCC6 and XRCC7 genes may participate in the pathogenesis of breast cancer. The aim of this Human Genome Epidemiology (HuGE) review and meta-analysis was to investigate associations between XRCC5, XRCC6 and XRCC7 genetic polymorphisms in the NHEJ pathway and breast cancer risk. Methods: Studies focusing on the relationship between genetic polymorphisms in XRCC5, XRCC6 and XRCC7 genes and susceptibility to breast cancer were selected from the Pubmed, Cochrane library, Embase, Web of Science, Springerlink, CNKI and CBM databases. Data were extracted by two independent reviewers. The meta-analysis was performed with Review Manager Version 5.1.6 and STATA Version 12.0 software. The odds ratio (OR) with 95% confidence interval (95%CI) was calculated based on the extracted data. Results: According to the inclusion criteria, we final included seven studies with a total of 2,864 breast cancer cases and 3,060 healthy controls. Meta-analysis results showed that rs3835 (G>A) and rs828907 (G>T) in XRCC5 gene, and rs132793 (G>A) in XRCC6 gene might increase the risk of breast cancer, while rs132788 G>T and rs6002421 (A>G) might be protective factors. However, there was no relationship between XRCC7 genetic polymorphisms and the risk of breast cancer. Conclusion: This meta-analysis suggests that the rs3835 G>A and rs828907 G>T in XRCC5 gene, rs6002421 (A>G), rs132788 (G>T) and rs132793 (G>A) in XRCC6 gene might be risk factors for breast cancer, while the rs132788 (G>T) and rs6002421 (A>G) in XRCC6 gene might be protective.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.6
• /
• pp.2541-2545
• /
• 2012

Objective: To investigate any association between XRCC1 and XRCC3 polymorphisms and outcome of platinum-based chemotherapy in ovarian cancer patients. Methods: With a prospective study design was cases were consecutively collected from January 2005 to January 2007. All 310 included patients were followed-up until the end of January 2010. Genotyping of XRCC1 and XRCC3 polymorphisms was conducted by TaqMan Gene Expression assays. Results: A total of 191 patients died during follow-up. Our study showed a lower survival rate in XRCC1 399 Arg/Arg genotype than Gln/Gln, with a significant increased risk of death (HR=1.69, 95%CI=1.07-2.78). Similarly, those carrying XRCC3 Thr/Thr genotype had a increased risk as compare to the Met/Met genotype, with a HR (95% CI) of 1.90 (1.12-3.41). There was no significant association between XRCC1 Arg194Trp and XRCC1Arg280His gene polymorphisms and ovarian cancer death. Conclusion: Our study demonstrates that polymorphisms in DNA repair genes have roles in the susceptibility and survival of ovarian cancer patients.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.6
• /
• pp.2811-2819
• /
• 2016

Multiple genetic and environmental factors have been reported to play key role in the development of nasopharyngeal carcinoma (NPC). Here, we investigated interactions of XRCC1 Arg399Gln and XRCC2 Arg188His polymorphisms and environmental factors in modulating susceptibility to NPC in Northeast India. One-hundred NPC patients, 90 first-degree relatives of patients and 120 controls were enrolled in the study. XRCC1 Arg399Gln and XRCC2 Arg188His polymorphisms were determined using PCR-RFLP, and the results were confirmed by DNA sequencing. Logistic regression (LR) and multifactor dimensionality reduction (MDR) approaches were applied for statistical analysis. The XRCC1 Gln/Gln genotype showed increased risk (OR=2.76; P<0.024) of NPC. However, individuals with both XRCC1 and XRCC2 polymorphic variants had 3.2 fold elevated risk (P<0.041). An enhanced risk of NPC was also observed in smoked meat (OR=4.07; P=0.004) and fermented fish consumers (OR=4.34, P=0.001), and tobacco-betel quid chewers (OR=7.00; P=0.0001) carrying XRCC1 polymorphic variants. However, smokers carrying defective XRCC1 gene showed the highest risk (OR = 7.47; P<0.0001). On MDR analysis, the best model for NPC risk was the five-factor model combination of XRCC1 variant genotype, fermented fish, smoked meat, smoking and chewing (CVC=10/10; TBA=0.636; P<0.0001); whereas in interaction entropy graphs, smoked meat and tobacco chewing showed synergistic interactions with XRCC1. These findings suggest that interaction of genetic and environmental factors might increase susceptibility to NPC in Northeast Indian populations.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.23
• /
• pp.10225-10229
• /
• 2015

Genetic polymorphisms in homologous recombination repair genes cause an abnormal development of cancerous cells. In the present study we evaluated the possibility of breast cancer association with single nucleotide polymorphisms of RAD51, XRCC2 and XRCC3 genes. Polymorphisms selected in this study were RAD51 135G/C, XRCC2 Arg188His; and XRCC3 Thr241Met. Each polymorphism was genotyped using Polymerase chain reaction-restriction fragment length polymorphism in study cohort of 306 females (156 breast cancer patients and 150 controls). We observed that heterozygous variant genotype (GC) of RAD51 135 G/C polymorphism was associated with a significantly (OR=2.70; 95%CI (0.63-1.79); p<0.03) increased risk of breast cancer. In case of the XRCC3 gene we observed that frequency of heterozygous (OR=2.88; 95%CI (1.02-8.14); p<0.02) and homozygous (OR=1.46; 95%CI (0.89-2.40); p<0.04) genotype of Thr241Met polymorphism were significantly higher in breast cancer patients. For the Arg188His polymorphism of XRCC2, ~2fold increase in breast cancer risk (OR=1.6, 95%CI = 0.73-3.50) was associated with GA genotype with a p value for trend of 0.03. Our results suggest that the 135G/C polymorphism of the RAD51, Thr241Met polymorphism of XRCC3 and Arg188His polymorphism of XRCC2 can be independent markers of breast cancer risk in Pakistan.

• Radiation Oncology Journal
• /
• v.24 no.1
• /
• pp.30-36
• /
• 2006

Purpose: It is well known from clinical experience that acute complications of chemoradiation therapy vary from patients to patients. However, there are no known factors to predict these acute complications before treatment starts. The human XRCC1 gene is known as a DNA base excision repair gene. We investigated the possibilities of XRCC1 gene polymorphisms as a predictor for the acute complications of chemoradiation therapy in colorectal cancer patients. Materials and Methods: From July 1997 to June 2003, 86 colorectal cancer patients (71 rectal cancer, 13 sigmoid colon cancer and 2 colon cancer patients) were treated with chemoradiation therapy at the Department of Radiation Oncology, Inha University Hospital. Twenty-two patients were in stage B, 50 were in stage C, 8 were in stage D and 6 patients were unresectable cases. External radiation therapy was delivered with 10MV X-ray at a 1.8 Gy fraction per day for a total dose of radiation of $30.6{\sim}59.4 Gy$ (median: 54 Gy). All the patients received 5-FU based chemotherapy regimen. We analyzed the acute complications of upper and lower gastrointestinal tract based on the RTOG complication scale. The initial and lowest WBC and platelet count were recorded during both the RT period and the whole treatment period. Allelic variants of the XRCC1 gene at codons 194, 280 and 399 were analyzed in the lymphocyte DNA by performing PCR-RFLP. Statistical analyses were carried out with the SAS (version 6.12) statistical package. Results: When all the variables were assessed on the multivariate analysis, recurrent disease revealed the factors that significantly correlated with upper gastrointestinal acute complications. Arg399Gln polymorph isms of the XRCC1 gene, the radiation dose and the frequencies of chemotherapy during radiation therapy were significantly correlated with lower gastrointestinal complications. Arg399Gln polymorph isms also affected the decrease of the WBC and platelet count during radiation therapy. Conclusion: Although the present sample size was too small for fully evaluating this hypothesis, this study suggests that Arg399Gln polymorph isms of the XRCC1 genes may be used as one of the predictors for acute complications of chemoradiation therapy in colorectal cancer patients.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.6
• /
• pp.2263-2268
• /
• 2015

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, $P_{heterogeneity}=0.00$, $I^2=83%$). 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, $P_{heterogeneity}=0.002$, $I^2=57%$). 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, $P_{heterogeneity}=0.54$, $I^2=0.00%$; Allele model: C vs. T: OR=0.708, 95 %=CI 0.605-0.829, p=0.000, $P_{heterogeneity}=0.000$, $I^2=92%$). 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.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.6
• /
• pp.3809-3813
• /
• 2013

Background: X-ray repair cross-complementing group 1 (XRCC1) plays a key role in the base excision repair pathway, as a scaffold protein that brings together proteins of the DNA repair complex. XRCC1 is reported to be a candidate influence on cancer risk. The aim of our present study was to assess the association of rs1799782 (Arg194Trp) and rs25487 (Arg399Gln) XRCC1 gene polymorphisms with breast cancer in the Saudi population. Materials and Methods: The two SNP's were analyzed in breast cancer patients and healthy control subjects. Genotypes were determined by TaqMan SNP genotype analysis technique and data were analyzed using Chi-square or t test and logistic regression analysis by SPSS16.0 software. Results and Conclusions: Results showed that rs1799782 significantly increased susceptibility to breast cancer with Arg/Trp, Arg/Trp+Trp/Trp genotypes and at Trp allele overall study. It also increased risk of breast cancer in older age patients (above 48) and with the ER positive category. XRCC1rs25487 (Arg399Gln) did not showed any significant association. In conclusion the XRCC1rs1799782 polymorphism may be involved in the etiology of breast cancer in the Saudi population. Confirmation of our findings in larger populations of different ethnicities is warranted.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.10
• /
• pp.4599-4608
• /
• 2016

Background: The x-ray repair cross-complementing group 3 (XRCC3) encodes a protein involved in the homologous recombination repair (HRR) pathway for double-strand DNA repair. Associations of the XRCC3 Thr241Met polymorphism with various cancers have been widely reported. However, published data on links between XRCC3 Thr241Met and gastrointestinal (GI) cancer risk are inconsistent. Objective and Methods: A meta-analysis was conducted to characterize the relationship between XRCC3 Thr241Met polymorphisms and GI cancer risk. Pooled odds ratios (ORs) and 95.0% confidence intervals were assessed using random- or fixed- effect models for 28.0 relevant articles with 30.0 studies containing 7,649.0 cases and 11,123.0 controls. Results: The results of the overall meta-analysis suggested a borderline association between the XRCC3 Thr241Met polymorphism and GI cancer susceptibility (T vs. C: OR=1.18, 9 % CI=1.0-1.4, POR=0.04; TT vs. CT+CC: OR=1.3, 95 % CI=1.0-1.6, POR=0.04). After removing studies not conforming to Hardy-Weinberg equilibrium (HWE), however, this association disappeared (T vs. C: OR=1.00, 95 % CI=0.9-1.1, POR=0.96; TT vs. CT+CC: OR=0.9, 95 % CI=0.8-1.1, POR=0.72). When stratified by ethnicity, source of controls or cancer type, although some associations between XRCC3 Thr241Met polymorphism and GI cancer susceptibility were detected, these associations no longer existed after removing studies not conforming to HWE. Conclusion: Our meta-analysis suggests that the XRCC3 Thr241Met polymorphism is not associated with risk of GI cancer based on current evidence.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.7
• /
• pp.3431-3436
• /
• 2012

Objective: X-ray cross-complementing group 4 (XRCC4) is a major repair gene for DNA double-strand breaks (DSB) in the non-homologous end-joining (NHEJ) pathway. Several potentially functional polymorphisms of the XRCC4 gene have been implicated in breast cancer risk, but individually published studies showed inconclusive results. The aim of this meta-analysis was to investigate the association between XRCC4 polymorphisms and the risk of breast cancer. Methods: The MEDLINE, EMBASE, Web of science and CBM databases were searched for all relevant articles published up to June 20, 2012. Potential associations were assessed with comparisons of the total mutation rate (TMR), complete mutation rate (CMR) and partial mutation rate (PMR) in cases and controls. Statistical analyses were performed using RevMan 5.1.6 and STATA 12.0 software. Results: Five studies were included with a total of 5,165 breast cancer cases and 4,839 healthy controls. Meta-analysis results showed that mutations of rs2075686 (C>T) and rs6869366 (G>T) in the XRCC4 gene were associated with increased risk of breast cancer, while rs2075685 (G>T) and rs10057194 (A>G) might decrease the risk of breast cancer. However, rs1805377 (A>G), rs1056503 (G>T), rs28360317 (ins>del) and rs3734091 (A>G) polymorphisms of XRCC4 gene did not appear to have an influence on breast cancer susceptibility. Conclusion: Results from the current meta-analysis suggest that the rs2075685 (G>T) and rs6869366 (G>T) polymorphisms of the XRCC4 gene might increase the risk of breast cancer, whereas rs2075685 (G>T) and rs10057194 (A>G) might be protective factors.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.6
• /
• pp.2747-2751
• /
• 2014

Background: DNA repair pathways play a crucial role in maintaining the human genome. Previous studies associated DNA repair gene polymorphisms (XPD Lys751Gln, XRCC1 Arg280His and XRCC1 Arg399Gln) with nasopharyngeal carcinoma. These non-synonymous polymorphisms may alter DNA repair capacity and thus increase or decrease susceptibility. The present study aimed to determine the genotype distribution of XPD codon 751, XRCC1 codon 280 and codon 399 polymorphisms and haplotype associations among NPC cases and controls in the Malaysian population. Materials and Methods: We selected 157 NPC cases and 136 controls from two hospitals in Kuala Lumpur, Malaysia for this study. The polymorphisms studied were genotyped by PCR-RFLP assay and allele and genotype frequenci es, haplotype and linkage disequilibrium were determined using SNPstat software. Results: For the XPD Lys751Gln polymorphism, the frequency of the Lys allele was higher in cases than in controls (94.5% versus 85.0%). For the XRCC1 Arg280His polymorphism, the frequency of Arg allele was 90.0% and 89.0% in cases and controls, respectively and for XRCC1 Arg399Gln the frequency of the Arg allele was 72.0% and 72.8% in cases and controls respectively. All three polymorphisms were in linkage disequilibrium. The odds ratio from haplotype analysis for these three polymorphisms and their association with NPC was 1.93 (95%CI: 0.90-4.16) for haplotype CGC vs AGC allele combinations. The global haplotypte association with NPC gave a p-value of 0.054. Conclusions: Our study provides an estimate of allele and genotype frequencies of XRCC1Arg280His, XRCC1 Arg399Gln and XPD Lys751Gln polymorphisms in the Malaysian population and showed no association with nasopharyngeal cancer.