Polymorphisms in ERCC1 and ERCC2/XPD genes and carcinogen DNA adducts in human lung.
ABSTRACT: In this exploratory study, we aimed to investigate whether polymorphisms in excision repair cross-complementing group 1 (ERCC1) and excision repair cross-complementing group 2/xeroderma pigmentosum group D (ERCC2/XPD) in the nucleotide excision repair (NER) pathways associated with DNA adducts in human lung tissue. We also analyzed the association stratified by the major histologic subtypes of non-small cell lung cancer (NSCLC): adenocarcinoma (ADC) and squamous cell carcinoma (SQCC).The study population consisted of 107 early stage NSCLC patients from the Massachusetts General Hospital (MGH) in Boston who underwent curative surgical resection. Genotyping was completed for SNPs in ERCC1 [C8092A (rs3212986) and C118T (rs11615)] and ERCC2/XPD [Asp312Asn (rs1799793) and Lys751Gln (rs1052559)] using a PCR-RFLP method and the PCR with fluorescent allele-specific oligonucleotide probes (Taqman). DNA adduct levels were measured as relative adduct levels per 10(10) nucleotides by (32)P-postlabeling in non-tumor lung tissue.After adjusting for potential confounders, lung DNA adduct levels increased by 103.2% [95% confidence interval (CI), -11.5 to 366.6] for ERCC2/XPD rs1799793AA genotype compared with their corresponding wild type homozygous genotypes in overall NSCLC, but the difference did not reach statistical significance. When we stratified by the subtypes of NSCLC, we found that DNA adducts levels in lung increased by 204.9% (95% CI, 0.8 to 822.2, P=0.059) for ERCC2/XPD rs1799793AA genotype in subjects with SQCC and the trend was statistically significant (P for trend=0.0489).Polymorphisms in ERCC2/XPD Asp312Asn may be associated with increased DNA adduct levels in the lung, especially among subjects with SQCC. Further large scale studies are needed to confirm our findings.
Project description:Benzo[a]pyrene diol epoxide (BPDE)-induced DNA adducts are a risk factor for tobacco-related cancers. Excision repair cross-complementing complementation group 1 (ERCC1) and excision repair cross-complementing complementation group 2/xeroderma pigmentosum D (ERCC2/XPD) participate in the nucleotide excision repair (NER) pathway that removes BPDE-DNA adducts; however, few studies have provided population-based evidence for this association. Therefore, we assayed for levels of in vitro BPDE-induced DNA adducts and genotypes of single-nucleotide polymorphisms (SNPs) of the NER genes ERCC1 (rs3212986 and rs11615) and ERCC2/XPD (rs13181, rs1799793 and rs238406) in 707 healthy non-Hispanic whites. The linear trend test of increased adduct values in never to former to current smokers was statistically significant (P(trend) = 0.0107). The median DNA adduct levels for the ERCC2 rs1799793 GG, GA and AA genotypes were 23, 29 and 30, respectively (P(trend) = 0.057), but this trend was not observed for other SNPs. After adjustment for covariates, adduct values larger than the median value were significantly associated with the genotypes ERCC1 rs3212986TT [odds ratio (OR) = 1.89, 95% confidence interval (CI) = 1.03-3.48] and ERCC2/XPD rs238406AA (OR = 0.64, 95% CI = 0.41-0.99) and rs238406CA (OR = 0.63, 95% CI = 0.45-0.89) compared with their corresponding wild-type homozygous genotypes. The results of haplotype analysis further suggested that haplotypes CAC and CGA of ERCC2/XPD, TC of ERCC1 and CACTC of ERCC2/XPD and ERCC1 were significantly associated with high levels of DNA adducts compared with their most common haplotypes. Our findings suggest that the genotypes and haplotypes of ERCC1 and ERCC2/XPD may have an effect on in vitro BPDE-induced DNA adduct levels.
Project description:Genetic variations or polymorphisms within genes of the nucleotide excision repair (NER) pathway alter DNA repair capacity. Reduced DNA repair (NER) capacity may result in tumors that are more susceptible to cisplatin chemotherapy, which functions by causing DNA damage. We investigated the potential predictive significance of functional NER single nucleotide polymorphisms in esophageal cancer patients treated with (n = 262) or without (n = 108) cisplatin.Four NER polymorphisms XPD Asp312Asn; XPD Lys751Gln, ERCC1 8092C/A, and ERCC1 codon 118C/T were each assessed in polymorphism-cisplatin treatment interactions for overall survival (OS), with progression-free survival (PFS) as a secondary endpoint.No associations with ERCC1 118 were found. Polymorphism-cisplatin interactions were highly significant in both OS (P = 0.002, P = 0.0001, and P < 0.0001) and PFS (P = 0.006, P = 0.008, and P = 0.0007) for XPD 312, XPD 751, and ERCC1 8092, respectively. In cisplatin-treated patients, variant alleles of XPD 312, XPD 751, and ERCC1 8092 were each associated with significantly improved OS (and PFS): adjusted hazard ratios of homozygous variants versus wild-type ranged from 0.22 [95% confidence interval (CI): 0.1-0.5] to 0.31 (95% CI: 0.1-0.7). In contrast, in patients who did not receive cisplatin, variant alleles of XPD 751 and ERCC1 8092 had significantly worse survival, with adjusted hazard ratios of homozygous variants ranging from 2.47 (95% CI: 1.1-5.5) to 3.73 (95% CI: 1.6-8.7). Haplotype analyses affirmed these results.DNA repair polymorphisms are associated with OS and PFS, and if validated may predict for benefit from cisplatin therapy in patients with esophageal cancer.
Project description:<h4>Background</h4>Benzo[a]pyrene(B[a]P), and its ultimate metabolite Benzo[a]pyrene 7,8-diol 9,10-epoxide (BPDE), are classic DNA damaging carcinogens. DNA damage caused by BPDE is normally repaired by Nucleotide Excision Repair (NER), of which ERCC1 and ERCC2/XPD exert an indispensable role. Genetic variations in ERCC1 and ERCC2 have been related to DNA repair efficiency. In this study we used lymphocytes from healthy individuals to show that polymorphisms in ERCC1 and ERCC2 are directly associated with decreased DNA repair efficiency.<h4>Methods</h4>ERCC1 (rs3212986 and rs11615) and ERCC2 (rs13181, rs1799793 and rs238406) were genotyped in 818 healthy Han individuals from the northeast of China. BPDE induced DNA adducts in lymphocytes were assessed by high performance liquid chromatography (HPLC) in 282 randomly selected participants. The effect of ERCC1 rs3212986 and ERCC2 rs238406 on DNA damage caused by B[a]P was assessed with a modified comet assay.<h4>Results</h4>We found that the variant genotypes of ERCC1 rs3212986 and ERCC2 rs238406 were associated with the high levels of BPDE-DNA adducts. Especially ERCC1 rs3212986 A-allele variant was significantly associated with the high BPDE-DNA adducts. Haplotype analysis showed that the ERCC1 haplotype AC (OR?=?2.36, 95% CI?=?1.84-2.97), ERCC2 haplotype AGA (OR?=?1.51, 95% CI?=?1.06-2.15) and haplotype block AGAAC (OR?=?5.28, 95% CI?=?2.95-9.43), AGCAC (OR?=?1.35 95% CI?=?1.13-1.60) were linked with high BPDE-DNA adducts. In addition, we found that the combined minor alleles of ERCC1 rs3212986 and ERCC2 rs238406 were associated with a reduced DNA repair capacity.<h4>Conclusions</h4>Our results suggest that the variant genotypes of ERCC1 rs3212986 and ERCC2 rs238406 are associated with decreased repair efficiency of BPDE induced DNA damage, and may be predictive for an individual's DNA repair capacity in response to environmental carcinogens.
Project description:The ERCC1 and ERCC2 genes are important in repairing DNA damage and genomic instability, and are involved in the nucleotide excision repair pathway. We hypothesized that single nucleotide polymorphisms (SNPs) in ERCC1 and ERCC2 are associated with the risk of colorectal cancer in a Chinese population. To test this hypothesis, we genotyped four functional SNPs (ERCC1 Asn118Asn, C8092A, ERCC2 Asp312Asn, and Lys751Gln) in a case-control study with 213 colorectal cancer cases and 240 cancer-free controls. We found that the ERCC1 C8092A polymorphism AA and CA/AA variant genotypes were associated with a significantly increased risk of colorectal cancer, compared with the CC genotype (OR = 2.50, 95% CI = 1.10-5.70 for AA versus CC, and OR = 1.58, 95% CI = 1.08-2.30 for CA/AA versus CC). Furthermore, the effect appeared to be more prominent among men, smokers, drinkers, and patients with rectal cancer. However, no other SNPs were observed for any significant association with colorectal cancer risk. These results suggest that the ERCC1 C8092A polymorphism may contribute to colorectal cancer susceptibility in the Chinese population. Further large and functional studies are needed to confirm our findings.
Project description:Base excision repair and nucleotide excision repair are vital responses to multiple types of DNA damage, including damage from tobacco exposure. Single-nucleotide polymorphisms (SNP) in these pathways may affect DNA repair capacity and therefore influence risk for cancer development. We performed a clinic-based, case-control study comprising 481 consecutive patients with confirmed pancreatic adenocarcinoma and 625 healthy controls. Allele and genotype frequencies for 16 SNPs in DNA repair genes ERCC1, XPD/ERCC2, XPC, XPF/ERCC4, OGG1, and XRCC1 were compared after adjusting for age, sex, and smoking history. Subgroup analysis by sex and smoking history was performed. Carriers of one or two XPF/ERCC4 minor alleles at R415Q had decreased risk of pancreatic adenocarcinoma compared with those who had two major alleles [odds ratio (OR), 0.59; 95% confidence interval (95% CI), 0.40-0.85]. Heavy smokers (>40 pack-years) had increased risk for cancer if they were carriers of at least one minor allele for XPD/ERCC2 at D312N (OR, 2.78; 95% CI, 1.28-6.04) or D711D (OR, 2.19; 95% CI, 1.01-4.73). No other significant differences in risk were identified. Minor alleles in DNA repair genes XPF/ERCC4 and XPD/ERCC2 were associated with altered risk for pancreatic cancer.
Project description:<h4>Background</h4>Potential xeroderma pigmentosum group D (XPD), also called excision repair cross-complimentary group two (ERCC2), Lys751Gln and Asp312Asn polymorphisms have been implicated in gastric cancer risk among different ethnicities.<h4>Methods</h4>We aimed to explore the effect of XPD Lys751Gln and Asp312Asn polymorphisms on the susceptibility to gastric cancer among different ethnicities through a systematic review and meta-analysis. Each initially included article was scored for quality appraisal. Desirable data were extracted and registered into databases. 13 studies were ultimately eligible for the meta-analysis of Lys751Gln polymorphism and 9 studies for the meta-analysis of Asp312Asn polymorphism. We adopted the most probably appropriate genetic model (recessive model) for both Lys751Gln and Asp312Asn polymorphisms. Potential sources of heterogeneity were sought out via subgroup and sensitivity analyses, and publication biases were estimated.<h4>Results</h4>Statistically significant findings were apparently noted in Asians but not in Caucasians for both XPD Lys751Gln and XPD Asp312Asn polymorphisms. A statistically significant finding could be seen in noncardia-type gastric cancer for XPD Lys751Gln polymorphism. A statistically significant finding could also be seen in high quality subgroup, small-and-moderate sample size subgroup, articles published after 2007, or PCR-RFLP genotyping subgroup for XPD Asp312Asn polymorphism.<h4>Conclusions</h4>Our meta-analysis indicates that XPD Gln751Gln (CC) genotype and Asn312Asn (AA) genotype may seem to be more susceptible to gastric cancer in Asian populations but not in Caucasian populations, suggesting that the two genotypes may be important biomarkers of gastric cancer susceptibility for Asian populations, the assumption that needs to be further confirmed in well-designed studies among different ethnicities. Gln751Gln (CC) genotype may also be associated with noncardia-type gastric cancer risk, which should also be confirmed among different ethnicities in the future.
Project description:<h4>Objective</h4>Xeroderma pigmentosum group D (XPD) is an essential gene involved in the nucleotide excision repair (NER) pathway. Two commonly studied single nucleotide polymorphisms (SNPs) of XPD (Lys751Gln, A>C, rs13181; Asp312Asn, G>A, rs1799793) are implicated in the modulation of DNA repair capacity, thus related to the responses to platinum-based chemotherapy. Here we performed a meta-analysis to better evaluate the association between the two XPD SNPs and clinical outcome of platinum-based chemotherapy in non-small cell lung cancer (NSCLC) patients.<h4>Methods</h4>A comprehensive search of PubMed database was conducted to identify relevant articles. Primary outcomes included objective response (i.e., complete response + partial response vs. stable disease + progressive disease), progression-free survival (PFS) and overall survival (OS). The pooled and 95% confidence intervals (CIs) of ORs (odds ratios) and HRs (hazard ratios) were estimated using the fixed or random effect model.<h4>Results</h4>Twenty-four studies were eligible according to the inclusion criteria. None of the XPD Lys751Gln/Asp312Asn polymorphisms was associated with objective response, PFS or OS in NSCLC patients treated with platinum drugs. However, in stratified analysis by ethnicity, the XPD Lys751Gln (A>C) polymorphism was not significantly associated with increased response in Caucasians (OR=1.35, 95%CI=1.0-1.83, P=0.122 for heterogeneity) but was associated with decreased PFS in Asians (HR=1.39, 95%CI=1.07-1.81, P=0.879 for heterogeneity). Furthermore, a statistically significant difference existed in the estimates of effect between the two ethnicities (P=0.014 for TR; P<0.001 for PFS).<h4>Conclusions</h4>XPD Lys751Gln (A>C) may have inverse predictive and prognostic role in platinum-based treatment of NSCLC according to different ethnicities. Further studies are needed to validate our findings.
Project description:<h4>Objectives</h4>We aimed to determine the associations of genetic polymorphisms of excision repair cross-complementation group 1 (ERCC1) rs11615, xeroderma pigmentosum group D (XPD/ERCC2) rs13181, X-ray repair cross complementing group 1 (XRCC1) rs25487, XRCC3 rs1799794, and breast cancer susceptibility gene 1 (BRCA1) rs1799966 from the DNA repair pathway and multiple drug resistance 1 (MDR1/ABCB1) rs1045642 with response to chemotherapy and survival of non-small cell lung cancer (NSCLC) in a Chinese population.<h4>Materials and methods</h4>A total of 352 NSCLC patients were enrolled to evaluate the associations of the six SNPs with response to chemotherapy and overall survival. Logistic regressions were applied to test the associations of genetic polymorphisms with response to chemotherapy in 161 advanced NSCLC patients. Overall survival was analyzed in 161 advanced and 156 early stage NSCLC patients using the Kaplan-Meier method with log-rank test, respectively. Multivariate Cox proportional hazards model was performed to determine the factors independently associated with NSCLC prognosis.<h4>Results</h4>BRCA1 rs1799966 minor allele C (TC+CC vs. TT, OR = 0.402, 95% CI = 0.204-0.794, p = 0.008) and MDR1/ABCB1 rs1045642 minor allele A (GA +AA vs. GG, OR = 0.478, 95% CI = 0.244-0.934, p = 0.030) were associated with a better response to chemotherapy in advanced NSCLC patients. Survival analyses indicated that BRCA1 rs1799966 TC+CC genotypes were associated with a decreased risk of death (HR = 0.617, 95% CI = 0.402-0.948, p = 0.028) in advanced NSCLC patients, and the association was still significant after the adjustment for covariates. Multivariate Cox regression analysis showed that ERCC1 rs11615 AA genotype (P = 0.020) and smoking (p = 0.037) were associated with increased risks of death in early stage NSCLC patients after surgery.<h4>Conclusions</h4>Polymorphisms of genes in DNA repair pathway and MDR1 could contribute to chemotherapy response and survival of patients with NSCLC.
Project description:Esophageal cancer (EC) is a very aggressive tumor, and no reliable prognostic markers exist especially for resectable advanced neoplasia. The principal aim of this study was to investigate the association of germline polymorphisms in nucleotide excision repair (NER) pathway genes with the overall survival (OS) of patients with advanced EC. As a second aim, we also studied the association of NER gene variants with response to cisplatin-based chemotherapy. Among the EC patients referred to our Institution between 2004 and 2012, we selected a cohort of 180 patients diagnosed with a clinical tumor stage ranging from IIB and IVA. Patients were genotyped for four NER variants, two in the ERCC1 (rs11615 and rs3212986) and two in the ERCC2/XPD (rs1799793 and rs13181) genes. Kaplan-Meier analyses and Cox proportional hazards model were used to evaluate the associations of the selected variants with OS; association with response to neoadjuvant therapy was investigated using logistic regression. Results showed that the ERCC1 rs3212986 and the ERCC2/XPD rs1799793 were significantly associated with shorter OS. On the contrary, response association analysis displayed that, while rs11615 and rs3212986 in ERCC1 were associated with response, both ERCC2/XPD variants were not. By creating survival prediction models, we showed that the rs3212986 and the rs1799793 have a better predictability of the tumor stage alone. Furthermore, they were able to improve the power of the clinical model (AUC = 0.660 vs. AUC = 0.548, p = 0.004). In conclusion, our results indicate that the ERCC1 rs3212986 and the ERCC2/XPD rs1799793 could be used as surrogate markers for a better stratification of EC patients with advanced resectable tumor.
Project description:Various DNA alterations can be caused by exposure to environmental and endogenous carcinogens. Most of these alterations, if not repaired, can result in genetic instability, mutagenesis and cell death. DNA repair mechanisms are important for maintaining DNA integrity and preventing carcinogenesis. Recent lung cancer studies have focused on identifying the effects of single nucleotide polymorphisms (SNPs) in candidate genes, among which DNA repair genes are increasingly being studied. Genetic variations in DNA repair genes are thought to modulate DNA repair capacity and are suggested to be related to lung cancer risk. We identified a sufficient number of epidemiologic studies on lung cancer to conduct a meta-analysis for genetic polymorphisms in nucleotide excision repair pathway genes, focusing on xeroderma pigmentosum group A (XPA), excision repair cross complementing group 1 (ERCC1), ERCC2/XPD, ERCC4/XPF and ERCC5/XPG. We found an increased risk of lung cancer among subjects carrying the ERCC2 751Gln/Gln genotype (odds ratio (OR) = 1.30, 95% confidence interval (CI) = 1.14 - 1.49). We found a protective effect of the XPA 23G/G genotype (OR = 0.75, 95% CI = 0.59 - 0.95). Considering the data available, it can be conjectured that if there is any risk association between a single SNP and lung cancer, the risk fluctuation will probably be minimal. Advances in the identification of new polymorphisms and in high-throughput genotyping techniques will facilitate the analysis of multiple genes in multiple DNA repair pathways. Therefore, it is likely that the defining feature of future epidemiologic studies will be the simultaneous analysis of large samples.