XPC Polymorphisms Research Articles

XPC Polymorphism and Risk for Lung Cancer in North Indian Patients Treated with Platinum Based Chemotherapy and Its Association with Clinical Outcomes.

Xeroderma pigmentosum complementation group C plays an important role in the human repair system. As reported in previous studies its polymorphism are associated with lung cancer susceptibility. The purpose of this study is to investigate the association of XPC gene with lung cancer susceptibility, overall response and clinical outcomes amongst North Indians. A hospital based study of 370 lung cancer cases and 370 healthy controls was conducted and genotypes were determined using PCR-RFLP assay. Results were assessed using logistic linear regression adjusted for age, sex and smoking status. Survival analysis was conducted using Kaplan-Meier survival analysis and Cox regression analysis. The treatment outcomes of 167 lung cancer patients treated with platinum based chemotherapy were evaluated.The mutant genotypic variant of XPC Lys939Gln has been associated with elevated risk of lung cancer(OR:2.30;95%CI:1.41-3.73;p=0.0007) whereasXPC Ala499Val showed a highly protective effect (OR:0.25;95%CI:0.10-0.63;p=0.003). The mutant genotype of XPC Lys939Gln presented a higher risk of developing lung cancer in heavy smokers (OR: 3.71; 95%CI:1.46-9.45; p=0.005). The survival analysis presented that heterozygous genotype showed least survival in comparison with mutant genotype inXPCAla499Val genetic variant whereas no significant association was observed in XPC Lys939Gln. In conclusion, XPC Lys939Gln is associated with significant risk towards the lung cancer whereas on contrary XPC Ala499Val shows a protective effect.

Polymorphisms in the XPC gene and gastric cancer susceptibility in a Southern Chinese population.

Previous studies have reported that XPC gene polymorphisms may modify the individual susceptibility to gastric cancer. In this case–control study with a total of 1,142 cases and 1,173 controls, four potentially functional polymorphisms were genotyped in the XPC gene (rs2228001 A>C, rs2228000 C>T, rs2607775 C>G, and rs1870134 G>C) by Taqman assays and their associations were analyzed with the risk of gastric cancer in a Southern Chinese population. No significant association between any of XPC polymorphisms and gastric cancer risk was detected except for a borderline association with the rs2228000 CT/TT genotype (crude odds ratio =0.86, 95% confidence interval =0.73–1.02, P=0.088) when compared to the rs2228000 CC genotype. Further stratified analysis revealed that the protective effect of rs2228000 CT/TT on the risk of gastric cancer was only significant among subjects older than 58 years. In summary, results indicated that genetic variations in XPC gene may play a weak effect on gastric cancer susceptibility in Southern Chinese population, which warrants further confirmation in larger prospective studies with different ethnic populations.

Analysis of DNA Repair Genes Polymorphisms in Breast Cancer.

Genetic polymorphisms in the DNA repair genes may be associated with increased cancer risk. The purpose of this study was to evaluate the association of the DNA repair genes polymorphisms with the risk of breast cancer development. The study included 200 breast cancer patients and 200 healthy controls. The following polymorphisms were studied: C/G (Ser326Cys, rs1052133) of the hOGG1, A/C (IVS5+33, rs3212961) of the ERCC1, A/C (Lys939Gln, rs2228001) of the XPC, C/T (Thr241Met, rs861539) of the XRCC3, G/T (Leu787Leu, rs1800392) of the WRN and G/T (Ser307Ser, rs1056503) of the XRCC4 gene. Presented study showed statistically significant increase in the breast cancer development risk of the G/G hOGG1 genotype (OR 8.13; 95% CI, 4.37-15.14; p<0.001) and for the G hOGG1 allele (OR 5.11; 95% CI, 3.69-7.06; p<0.001), as well as for the C/C ERCC1 genotype (OR 10.61; 95% CI, 5.72-19.69; p<0.001) and the C ERCC1 allele (OR 4.66; 95% CI, 3.43-6.34; p<0.001) in patients with breast cancer in comparison with healthy control group. We also observed positive association of the C/C XPC genotype (OR 3.80; 95% CI, 2.27-6.38; p<0.001) as well as the C XPC allele occurrence with an increased breast cancer development risk (OR 2.65; 95% CI, 1.98-3.55; p<0.001). Furthermore, we found an association of the G/T WRN gene polymorphism with increased risk of carcinoma. The hOGG1, ERCC1, XPC and WRN genes polymorphisms may be related to development of breast cancer.

Study of Association between Pre-Senile Cataracts and the Polymorphisms rs2228000 in XPC and rs1042522 in p53 in Spanish Population.

PurposeTo determine if the presence of certain polymorphisms in the DNA repair gene XPC and the apoptosis inductor gene p53 is associated with pre-senile cataract development.MethodsWe have performed a retrospective study over three groups of patients. The group with pre-senile cataract formed by 72 patients younger than 55 with cataract surgery. The group with senile cataract formed by 101 patients older than 55 with cataract surgery. The group without cataract was formed by 42 subjects older than 55 without lens opacities. We analyzed the presence of SNP rs2228000 from XPC and rs1042522 from p53; and the relationship between risk factors such as smoking, alcohol intake, hypertension or diabetes.ResultsThe comparison of the genotype distribution in XPC, within the different groups, did not show any statistically significant association in any of our analysis (p>0,05). The comparison of the genotype distribution in p53 within the different groups did not show any statistically significant association (p>0,05); except for the comparison between the pre-senile cataract group and the group with senile cataract where the genotype Pro/Pro (C/C) in the recessive inheritance model showed a higher risk for developing pre-senile cataract (p = 0,031; OR = 1.04–15.97). This association decreased when we performed the analysis adjusting by the studied risk factors (p = 0.056).ConclusionsAllelic variants in the gene XPC are not associated with an increased risk for developing pre-senile cataract. The presence of the genotype Pro/Pro in p53 might be associated with a major risk for developing pre-senile cataract.

XPC (A2920C), XPF (T30028C), TP53 (Arg72Pro), and GSTP1 (Ile105Val) polymorphisms in prognosis of cutaneous melanoma.

This study aimed to evaluate whether XPC A2920C, XPF T30028C, TP53 Arg72Pro, and GSTP1 Ile105Val polymorphisms alter outcomes of cutaneous melanoma (CM) patients. DNA from 237 CM patients seen at the University of Campinas Teaching Hospital from April 2000 to February 2014 was analyzed by polymerase chain reaction and restriction fragment length polymorphism assays. The prognostic impact of genotypes of polymorphisms on progression-free survival (PFS) and overall survival (OS) of CM patients were examined using the Kaplan-Meier probability estimates and univariate and multivariate Cox regression analyses. At 60months of follow-up, shorter PFS and OS were seen in patients with XPF CC genotype (48.9 vs. 66.7%, P = 0.002; 77.9 vs. 83.5%, P = 0.006, respectively) and XPF CC + TP53 ArgArg (43.6 vs. 65.9%, P = 0.007; 71.6 vs. 84.8%, P = 0.006, respectively) compared with those with remaining genotypes (Kaplan-Meier estimates). Patients with XPF CC (hazard ratio (HR) 2.45, P = 0.002; HR 3.77, P = 0.005) and XPF CC + TP53 ArgArg (HR 2.67, P = 0.009; HR 4.04, P = 0.03) genotypes had more chance to present tumor progression in univariate and multivariate analyses, whereas patients with XPF CC (HR 2.78, P = 0.009) and XPF CC + TP53 ArgArg (HR 3.84, P = 0.01) genotypes were under greater risk of progressing to death in univariate analysis, compared with those with the remaining genotypes. The data suggest, for the first time, that inherited abnormalities in DNA repair pathway related to XPF 30028C and TP53 Arg72Pro polymorphisms act as prognostic factors for PFS and OS of CM patients.

3312 XPC (A2920C), XPF (T30028C), TP53 (Arg72Pro) and GSTP1 (Ile105Val) Polymorphisms in Prognosis of Patients with Cutaneous Melanoma

3312 XPC (A2920C), XPF (T30028C), TP53 (Arg72Pro) and GSTP1 (Ile105Val) Polymorphisms in Prognosis of Patients with Cutaneous Melanoma

DNA repair gene polymorphisms in B cell non-Hodgkin's lymphoma.

Cancer is a group of diseases characterized by DNA injury, and genetic and environmental factors are important in the etiology of the cancers. It is well known that there are association variabilities in DNA repairment and sensitivity against the cancer. The aim of this study is to look for some important gene polymorphisms associated with DNA repair in cases with B cell non-Hodgkin's lymphoma (B-NHL). Ninety-four cases with NHL and 96 healthy controls were included in this study. ERCC2 (Lys751Gln), XPC (Gln939Lys), ERCC5 (Asp1104His), and XRCC3 (Thr241Met) gene polymorphisms were studied by using Tm Shift Real-Time PCR Technology. ERCC5 Asp1104His polymorphism showed a protective effect against the B-NHL in individuals carrying this mutant allele (p = 0.009), and differences were more prominent in males (p = 0.001). When the patient and control groups were divided according to their smoking habit, the mutant allele of the XPC gene showed a protective effect in the nonsmoker group (p = 0.040). The mutant allele G of ERCC5 (CG) polymorphism was found to be protective against lymphoma (p = 0.010). There were no differences among cases with B-NHL and controls for ERCC2 codon 751, XPC codon 939, and XRCC3 codon 241 gene polymorphisms. DNA repair gene polymorphisms can affect the risk of lymphoma, and it will be useful to detect the DNA repair gene polymorphisms in cases with lymphoma in studies covering a higher number of cases.

Polymorphisms in XPC, XPD and XPG DNA repair genes and leukemia risk in a Tunisian population

Human DNA repair mechanisms protect the genome from DNA damage caused by endogenous and environmental agents. Polymorphisms in DNA repair genes and differences in repair capacity between individuals have been widely reported in different cancers. In this study we aimed to evaluate the associations between XPC Lys939Gln (rs2228001), XPD Lys751Gln (rs13181) and XPG Asp1104His (rs17655) polymorphisms and leukemia risk in a Tunisian population. Genotypes were determined by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) in 206 patients with leukemia and 206 healthy controls. We found increased risk of leukemia among subjects carrying the XPC 939Gln/Gln genotype (odds ratio [OR] = 2.48, 95% confidence interval [CI] = 1.353–4.560, p = 0.0042). Moreover, in subgroup analysis according to clinical types, patients with chronic myeloid leukemia (CML) showed a higher risk than patients with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) (OR = 3.87, 95% CI = 1.820–8.237, p = 0.0003). However, the XPD 751Gln allele may be protective against CML and AML development, and no significant differences in genotype frequencies were observed for the XPG gene between patients and controls. Further studies with larger samples and risk factor information are needed.

Polymorphisms in nucleotide excision repair genes and susceptibility to colorectal cancer in the Polish population.

Xeroderma pigmentosum (XP) is a rare autosomal recessive disease that is associated with a severe deficiency in nucleotide excision repair. Genetic polymorphisms in XP genes may be associated with a change in DNA repair capacity, which could be associated with colorectal cancer development. We assessed the association between 94 single nucleotide polymorphisms (SNPs) within seven XP genes (XPA–XPG) and the colorectal cancer risk in the Polish population. We genotyped 758 unselected patients with colorectal cancer and 1,841 healthy adults. We found that a significantly decreased risk of colorectal cancer was associated with XPC polymorphism rs2228000_CT genotype (OR 0.59; p < 0.0001) and the rs2228000_TT genotype (OR 0.29; p < 0.0001) compared to the reference genotype (CC). And an increased disease risk was associated with the XPD SNP, rs1799793_AG genotype (OR 1.44, p = 0.018) and rs1799793_AA genotype (OR 3.31, p < 0.0001) compared to the reference genotype. Haplotype analysis within XPC, XPD and XPG revealed haplotypes associated with an altered colorectal cancer risk. Stratified analysis by gender showed differences between the association of three SNPs: XPC rs2228000, XPD rs1799793 and XPD rs238406 in females and males. Association analysis between age of disease onset and polymorphisms in XPD (rs1799793) and XPC (rs2228000) revealed differences in the prevalence of these variants in patients under and over 50 years of age. Our results confirmed that polymorphisms in XPC and XPD may be associated with the risk of colorectal cancer.

Predictive impact of genetic polymorphisms in DNA repair genes on susceptibility and therapeutic outcomes to colorectal cancer patients.

Several hereditary syndromes characterized by defective DNA repair are associated with high risk of colorectal cancer (CRC). To explore whether common polymorphisms in DNA repair genes affect risk and prognosis of CRC, we evaluated the association between single nucleotide polymorphisms (SNPs) in XPG, XPC, and WRN gene and susceptibility of CRC, and clinical outcomes in a population-based case-control study. A total of 890 CRC cases and 910 controls recruited into the study provided a biologic sample. Individuals with variant genotypes of XPC Ala499Val appeared to be associated with the increased risk of CRC. WRN Cys1367Arg variants carriers showed an increased susceptibility for CRC. More importantly, the risk of CRC increased further in a combined analysis of multiple polymorphisms. Furthermore, stratified analyses revealed that XPG Arg1104His polymorphism was associated with tumor differentiation of CRC patients (P = 0.043). Log-rank test and adjusted multivariate Cox regression analysis verified that XPG Arg1104His variants were associated with a longer disease-free survival (DFS) [CG genotype: adjusted HR (95% confidence interval (CI)) = 0.163 (0.107-0.248), P < 0.001; CC genotype: adjusted HR (95% CI) = 0.333 (0.235-0.470), P < 0.001; CG/CC genotype: adjusted HR (95% CI) = 0.333 (0.235-0.470)] in patients with oxaliplatin-based chemotherapy (N = 718). Moreover, XPC Ala499Val CT genotype showed a significant impact on DFS [CC genotype: adjusted HR (95% CI) = 0.691 (0.528-0.904), P = 0.007; CT/CC genotype: adjusted HR (95% CI) = 0.602 (0.389-0.934), P = 0.024]. However, no correlation was found between WRN Cys1367Arg polymorphism and prognosis in CRC patients. Our findings will add to the literature on the impact of genetic variation in DNA repair genes involved in susceptibility for CRC and therapeutic outcomes in response to oxaliplatin-based chemotherapy.

Xpc, Xpf and P53 Polymorphisms Associated with Dna Repair and Prognosis in Cutaneous Melanoma

ABSTRACT Aim: XPC, XPF and P53 genes act on nucleotide excision repair of ultraviolet radiation-induced DNA damage and are involved in cutaneous melanoma (CM) development. The DNA repair ability is variable in humans.Variant C and wild Arg alleles of XPC A2920C and P53 Arg72Pro polymorphims encode proteins with lower activities in DNA repair than those encoded by other alleles, respectively. Variant C allele of XPF T30028C influences mRNA stability and affects levels of protein expression. This study aimed to evaluate whether these polymorphisms are associated with relapse-free survival (RFS) and overall survival (OS) of CM patients. Methods: We analyzed 232 CM patients diagnosed from 1989 to 2013 at a University Hospital. Genomic DNA of patients was analyzed by polymerase chain reaction, and enzymatic digestion, for discrimination of pertinent genotypes. RFS and OS were calculated using the univariate Kaplan-Meier estimate probabilities, and differences between survival curves were analyzed by the log-rank test. OS was calculated from the date of diagnosis until the date of death or last follow-up. Results: The median period of observation of patients in the study was 57 months (range: 1-285). At 60 months of follow-up, we observed that RFS of patients with XPF TT + TC genotypes was higher than that found in patients with CC genotype (73% vs 30%, P = 0.007). At this time, RFS was also higher in patients with XPF TT + TC plus P53 ArgPro + ProPro genotypes than in those with XPF CC plus P53 ArgArg genotypes (74% vs 19%, P = 0.004). At 120 months of follow-up, we observed that OS of patients with XPF TT + TC genotypes was higher than that observed in patients with CC genotype (86% vs 63%, P = 0.05). OS of patients with XPF TT + TC plus P53 ArgPro + ProPro genotypes was also higher than that found in patients with XPF CC plus P53 ArgArg genotypes (89% vs 68%, P = 0.07) at this time. In contrast, RFS and OS were worse in patients with Breslow thickness ≥1.5 mm (87% vs 52%, P = 0.0001; 88% vs 79%, P = 0.008), Clark level IV + V (79% vs 60%, P = 0.004; 86% vs 78%, P = 0.02) and advantage stage III + IV (77% vs 48% P = 0.0001; 88% vs 66% P = 0.0001), respectively. Conclusions: The data found herein provide evidence, for the first time, that inherited abnormality in DNA repair pathway related to XPF and P53 polymorphisms influence RFS and OS in CM patients. Disclosure: All authors have declared no conflicts of interest.

Association of XPC polymorphisms and lung cancer risk: a meta-analysis.

BackgroundXeroderma pigmentosum complementation group C gene (XPC) is a key member of nucleotide excision repair pathway and plays an important role in human DNA repair system. It is reported that several common polymorphisms of XPC are associated with susceptibility to lung cancer. However, the conclusion is still elusive.MethodThis meta-analysis was performed to determine the relationship between XPC polymorphisms (Lys939Gln, Ala499Val, and PAT) and lung cancer risk. Published literatures were identified by searching online databases and reference lists of relevant studies. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the association strength. Publication bias were detected by Egger’s and Begg’s test.ResultAfter strict screening, we identified 14 eligible studies in this meta-analysis, including 5647 lung cancer cases and 6908 controls. By pooling all eligible studies, we found that the homozygote Gln939Gln genotype was associated with a significantly increased risk of lung cancer in Asian population (GlnGln vs LysLys, OR = 1.229, 95% CI: 1.000–1.510; GlnGln vs LysLys/LysGln, OR = 1.257, 95% CI: 1.038–1.522). As for the PAT polymorphism, in Caucasian population, we found carriers of the −/− genotype were associated significantly reduced risk of lung cancer in homozygote comparison model (−/− vs +/+, OR = 0.735, 95% CI: 0.567–0.952).ConclusionIn this meta-analysis we found that Gln939Gln genotype was associated with significantly increased risk of lung cancer in Asian population; the PAT −/− genotype significantly reduced susceptibility to lung cancer in Caucasian population; while the XPC Ala499Val polymorphism was not associated with lung cancer risk.

XPC Lys939Gln and Ala499Val polymorphisms in colorectal cancer susceptibility: a meta-analysis of case–control studies

The XPC Lys939Gln and Ala499Val polymorphisms were likely to be involved with the development of colorectal cancer. However, there had been inconsistent reports of association. This meta-analysis of literatures was performed to draw a more precise estimation of the relationship. We systematically searched PubMed, Embase and Web of Science for relevant articles with a time limit of December 2012. The strength of association between the XPC Lys939Gln and Ala499Val polymorphisms and colorectal cancer susceptibility were assessed by odds ratio (OR) with the corresponding 95% confidence interval (95% CI). This meta-analysis including six case-control studies evaluated the associations between the two XPC polymorphisms (Lys939Gln, Ala499Val) and colorectal cancer susceptibility. For XPC Lys939Gln, no obvious associations were found for all genetic models [CC vs AA: OR (95% CI)=1.12 (0.94-1.32); CA vs AA: OR (95% CI)=1.08 (0.94-1.24); the dominant model: OR (95% CI)=1.09 (0.97-1.23); the recessive model: OR (95% CI)=1.07 (0.92-1.25)]. For XPC Ala499Val, no obvious associations were also not found for all genetic models [TT vs CC: OR (95% CI)=0.84 (0.65-1.10); CT vs CC: OR (95% CI)=1.00 (0.86-1.15); the dominant model: OR (95% CI)=0.98 (0.85-1.12); the recessive model: OR (95% CI)=0.87 (0.67-1.12)]. This meta-analysis suggested that both the XPC Lys939Gln and Ala499Val polymorphisms were not risk factors for increasing colorectal cancer.

Role of DNA Repair-related Gene Polymorphisms in Susceptibility to Risk of Prostate Cancer

We assessed the association between genetic variants of XPG, XPA, XPD, CSB, XPC and CCNH in the nucleotide excision repair (NER) pathway and risk of prostate cancer. We genotyped the XPG, XPA, XPD, CSB, XPC and CCNH polymorphisms by a 384-well plate format on the MassARRAY® platform. Multivariate logistical regression analysis was used to assess the associations between the six gene polymorphisms and risk of prostate cancer. Individuals carrying the XPG rs229614 TT (OR=2.01, 95%CI=1.35-3.27) genotype and T allele (OR=1.73, 95%CI=1.37-2.57) were moderately significantly associated with a higher risk of prostate cancer. Subjects with XPD rs13181 G allele had a marginally increased risk of prostate cancer, with adjusted OR(95%CI) of 1.53 (1.04-2.37). Moreover, individuals carrying with CSB rs2228526 GG genotype (OR=2.05, 95% CI=1.23-3.52) and G allele (OR=1.56, 95%CI=1.17-2.05) were associated with a higher increased risk of prostate cancer. The combination genotype of XPG rs2296147 T and CSB rs2228526 G allele had accumulative effect on the risk of this cancer, with an OR (95% CI) of 2.23(1.37-3.59). Our study indicates that XPG rs2296147 and CSB rs2228526 polymorphisms are significantly associated with increased risk of prostate cancer, and that combination of XPG rs2296147 T allele and CSB rs2228526 G allele is strongly associated with an increased risk.

The association of XPG and MMS19L polymorphisms response to chemotherapy in osteosarcoma

To assess the role of XPG, XPC, CCNH and MMS19L polymorphisms response to chemotherapy in osteosarcoma, and the clinical outcome of osteosarcoma. One hundred and sixty eight osteosarcoma patients who were histologically confirmed were enrolled in our study between January 2007 and March 2009. Genotyping of XPG, XPC, CCNH and MMS19L was performed in a 384-well plate format on the MassARRAY® platform. Individuals with rs2296147 TT genotype showed a better response as compared with CC genotype, with the OR (95% CI) of 3.89(1.49-10.95). Those carrying rs29001322 TT genotype presented better response to chemotherapy, and the OR (95% CI) was as high as 12.25(2.63-121.84). Patients carrying TT genotype of XPG rs2296147 and MMS19L rs29001322 showed a significantly longer overall survival than CC genotype, they had 0.37 and 0.31-fold risk of death when compared with wide-type of this gene. XPG rs2296147 and MMS19L rs29001322 are correlated with response to chemotherapy and prognosis of osteosarcoma. Our findings would provide important evidence for prognostic and therapeutic implications in osteosarcoma.

The impact of single-nucleotide polymorphisms (SNPs) in OGG1 and XPC on the age at onset of Huntington disease

The age at onset of Huntington disease (HD) shows a strong, negative correlation with the number of CAG repeats within the huntingtin (HTT) gene. However, this does not account for all the inter-individual variability seen among patients. In order to assess whether single-nucleotide polymorphisms (SNPs) in the OGG1 and XPC genes, both implicated in responses to oxidative stress, are associated with the age of onset of HD, 9 SNPs have been genotyped in 299 individuals with HD and 582 controls. After correction for multiple testing, two OGG1/XPC haplotypes were found to be associated with younger age at onset independently of the number of CAG repeats within the HTT gene. Both haplotypes contain XPC coding variants that would be expected to impact on protein function and/or variants in the 3′UTR that could result in altered protein levels via allele-specific mIR binding. One haplotype also contains the OGG1-326Cys (rs1052133) allele that has been associated with a lower 8-oxoG repair activity and is particularly sensitive to the cellular redox status. These results highlight the potential role of oxidative stress in determining the age at onset of HD.

Predictive Impact of Common Variations in DNA Repair Genes on Clinical Outcome of Osteosarcoma

We aimed to assess the role of XPG, XPC and MMS19L polymorphisms on response to chemotherapy in osteosarcomas, and the clinical outcomes. One hundred and eighty five osteosarcoma patients who were histologically confirmed were enrolled in our study between January 2007 and December 2009. Genotyping of XPG, XPC and MMS19L was performed in a 384-well plate format on the MassARRAY® platform. Individuals with XPG TT genotype and T allele were more likely to be better response to chemotherapy than CC genotype, with the OR (95% CI) of 4.17 (1.64-11.54) and 2.66 (1.39-5.11), respectively. Those carrying MMS19L TT genotype and T allele showed better response to chemotherapy, with ORs (95% CI) of 4.8 (1.56-17.7) and 2.3 (1.22-4.36), respectively. Patients carrying TT genotype of XPG and MMS19L showed a significantly longer overall survival than CC genotype, with a 0.47 and 0.30-fold risk of death when compared with the wild-type of the gene. XPG and MMS19L are correlated with response to chemotherapy and prognosis of osteosarcoma, so that they could be used as predictive markers for prognosis.

Genetic polymorphisms in RAD23B and XPC modulate DNA repair capacity and breast cancer risk in Puerto Rican women

Studies have shown that DNA repair capacity (DRC) is significantly decreased in breast cancer patients, but the molecular causes of inter-individual variation in DRC are unknown. We hypothesized that genetic variation in the nucleotide excision repair pathway genes can modulate DRC and breast cancer risk in Puerto Rican women. A total of 228 breast cancer cases and 418 controls were recruited throughout Puerto Rico. For all study participants, eight single nucleotide polymorphisms (SNPs) in the genes XPC, XPD, and RAD23B were genotyped using a TaqMan PCR, and the DRC levels of UV induced-DNA damage was measured in peripheral lymphocytes using a host cell reactivation assay. After adjustment for confounders, RAD23B rs1805329 (Ala249Val) was found to be significantly associated with breast cancer risk under all models tested (P < 0.001). There was also a significant association between breast cancer risk and RAD23B rs10739234 (intronic) under the recessive model (P = 0.003, OR: 2.72, 95% CI: 1.40-5.30). In cases, there was a statistically significant difference in mean DRC per genotype for RAD23B rs1805329 (P < 0.001) and XPC rs2607775 (P = 0.002). When we modeled the combined effect of multiple SNPs that each independently affected DRC on cancer risk, we observed incremental augmentations in risk with increasing number of risk genotypes at those loci (P overall model <0.001). The increase in adverse genotypes was also correlated with a progressive decrease in DRC values. Our data indicate an additive effect of the NER SNPs on DRC and breast cancer risk in Puerto Rican women.

Study on bladder cancer susceptibility and genetic polymorphisms of XPC, XPG, and CYP in smokers and non-smokers

AimTo investigate the gene susceptibility of bladder cancer and potential relation with smoking. MethodsAn analysis of SNPs were conducted among DNA repair genes of XPC, XPG, XRCC1, and six members of metabolic enzyme gene CYP 450 via TaqMan Probe-based polymerase chain reaction. A total of 130 patients with bladder cancer and 304 healthy controls were involved. ResultsPolymorphisms of XPC gene was related to bladder cancer. It was also related to smoking status in bladder cancer patients, as well as to tumor stage, male gender and older age. The XPG gene polymorphism was also related to bladder cancer yet it was prevalent in female non-smokers. No association was acquired for XRCC1 gene. The combination of more than 2 polymorphisms in DNA repair genes was associated with bladder cancer. No association was obtained in any of the metabolic enzyme gene of CYP450 with either bladder cancer or smoking status. ConclusionDNA repair genes XPC and XPG could be related to carcinogenesis and tumor progression of bladder cancer. Confirmation within larger population was warranted.

Assessment of the XPC (A2920C), XPF (T30028C), TP53 (Arg72Pro) and GSTP1 (Ile105Val) polymorphisms in the risk of cutaneous melanoma

We examined the influence of XPC A2920C, XPF T30028C, TP53 Arg72Pro and GSTP1 Ile105Val polymorphisms in the risk of cutaneous melanoma (CM). DNA from 146 CM patients and 146 controls was analysed by polymerase chain reaction (PCR)--restriction fragment length polymorphism (RFLP). The frequencies of XPC CC (15.1 vs. 6.9 %, P = 0.02), TP53 ArgArg (59.6 vs. 45.9 %, P = 0.02), XPC CC plus TP53 ArgArg (19.7 vs. 5.2 %, P = 0.01) and TP53 ArgArg plus GSTP1 IleIle (50.7 vs. 35.6 %, P = 0.03) genotypes were higher in patients than in controls. Carriers of the respective genotypes were under a 2.51 (95 % CI: 1.13-5.55), 1.76 (95 % CI: 1.09-2.83), 4.52 (95 % CI: 1.35-15.16), and 2.01 (95 % CI: 1.04-3.90)-fold increased risks for CM than others, respectively. An excess of TP53 ArgArg genotype was seen in patients with excessive sun exposure compared to patients with standard sun exposure (69.2 vs. 44.1 %, P = 0.02) and also compared to controls (69.2 vs. 45.9 %, P = 0.002). Individuals with TP53 ArgArg genotype and highly exposed to sunlight had 2.65 (95 % CI: 1.42-4.92)-fold increased risk for CM than others. XPC CC (27.8 vs. 10.4 %, P = 0.02) and the GSTP1 IleIle (58.3 vs. 36.8 %, P = 0.04) genotypes were more common in patients with advanced tumours than in patients with localized tumours and were also more common in these patients than in controls (27.8 vs. 6.9 %, P = 0.001; 58.3 vs. 37.0 %, P = 0.02, respectively). Individuals with the respective genotypes had 5.23 (95 % CI: 1.97-13.82)-fold and 2.38 (95 % CI: 1.13-5.01)-fold increased risks for advanced tumour than others, respectively. Our data suggest that inherited abnormalities of XPC, XPF, TP53 and GSTP1 pathways of the DNA repair, apoptosis and metabolism of reactive oxygen species are important determinants of CM in individuals from south-eastern Brazil.