Effects of ERCC1 expression in peripheral blood on the risk of head and neck cancer

Relationship between ERCC1 and XPC polymorphisms and the susceptibility to head and neck carcinoma: A systematic review, meta-analysis, and trial sequential analysis

OBJECTIVE

This meta-analysis was conducted to investigate the relationship between ERCC1 and XPC polymorphisms and the risk of head and neck cancer (HNC), incorporating more studies and additional analyses.

DESIGN

An exhaustive search of various databases, including PubMed/Medline, Web of Science, Scopus, and Cochrane Library was carried out, up until November 18, 2023, to identify pertinent studies. The Review Manager 5.3 software was employed to calculate the effect sizes, which were presented as the odds ratio (OR) along with a 95% confidence interval (CI).

RESULTS

The study found that the T allele (OR = 1.11; p-value = 0.02; 95%CI: 1.02, 1.22) and the TT genotype rs2228000 polymorphism in both the homozygous model (OR = 1.61, p-value = 0.02; 95%CI: 1.07, 2.42) and the recessive model (OR = 1.53; p-value = 0.02; 95%CI: 1.06, 2.22) had statistically significant associations. However, no significant associations were found for rs11615, rs3212986, rs735482, rs2228001, and PAT polymorphisms in any genetic models.

CONCLUSIONS

The meta-analysis revealed significant associations for the T allele and TT genotype rs2228000 polymorphism, but not for rs11615, rs3212986, rs735482, rs2228001, and PAT polymorphisms. The results highlight the impact of factors such as ethnicity, cancer subtype, and control source on these associations, emphasizing the intricate nature of genetic interactions in disease risk.

Genetic polymorphisms as potential pharmacogenetic biomarkers for platinum-based chemotherapy in non-small cell lung cancer

Platinum-based chemotherapy (PBC) is a widely used treatment for various solid tumors, including non-small cell lung cancer (NSCLC). However, its efficacy is often compromised by the emergence of drug resistance in patients. There is growing evidence that genetic variations may influence the susceptibility of NSCLC patients to develop resistance to PBC. Here, we provide a comprehensive overview of the mechanisms underlying platinum drug resistance and highlight the important role that genetic polymorphisms play in this process. This paper discussed the genetic variants that regulate DNA repair, cellular movement, drug transport, metabolic processing, and immune response, with a focus on their effects on response to PBC. The potential applications of these genetic polymorphisms as predictive indicators in clinical practice are explored, as are the challenges associated with their implementation.

Validation of Potential Protein Markers Predicting Chemoradioresistance in Early Cervical Cancer by Immunohistochemistry

Background

In a previous study, a proteomic panel consisting of BCL-2, HER2, CD133, CAIX, and ERCC1 significantly predicted survival in patients with locally advanced cervical cancer. However, the prognostic significance of these proteins has not been assessed in early cervical cancer. The present study investigated the clinical significance and chemoradioresistance prediction power of these proteins in patients with early-stage cervical cancer.

Materials and Methods

BCL-2, HER2, CD133, CAIX, and ERCC1 expression was determined by the immunohistochemical staining of 336 cervical cancer tissue microarrays. The associations of these proteins with clinicopathologic characteristics and disease progression were assessed.

Results

There was a trend of low CAIX expression (p=0.082) and high ERCC1 expression (p=0.059) in patients with a favorable response to adjuvant radiation. High HER2 expression was significantly associated with shorter disease-free survival (DFS) in the total group (5-year DFS of 80.1% vs. 92.2%, p=0.004). A prognostic significance remained in multivariate analysis (Hazard ratio, HR=2.10, p=0.029). In the adjuvant radiation group, low CAIX and high ERCC1 expression indicated significantly unfavorable DFS (75.0% vs. 89.0%, p=0.026 and 76.8% vs. 88.6%, p=0.022, respectively). Low CAIX expression remained an independent prognostic marker in multivariate analysis (HR=0.45, p=0.037). The combined molecular-clinical model using random survival forest method predicted DFS with improved power compared with that of the clinical variable model (C-index 0.77 vs. 0.71, p=0.006).

Conclusion

HER2, CAIX, and ERCC1 expression can be predictive protein markers for clinical outcomes in early cervical cancer patients treated primarily with radical surgery with or without adjuvant radiation.

Association of ERCC1 polymorphisms (rs3212986 and rs11615) with the risk of head and neck carcinomas based on case-control studies

PURPOSE

Current data regarding association between ERCC1 polymorphisms and the risk of head and neck squamous cell carcinomas (HNSCC) have shown controversial results. The current study aims to achieve a more accurate estimation of the association between two well-characterized ERCC1 polymorphisms (rs3212986 and rs11615) and HNSCC risk by a meta-analysis of all eligible studies.

METHODS

The meta-analysis was performed by reviewing seven studies on the ERCC1 C8092A (rs3212986) polymorphism including 2055 cases and 2635 controls and four studies on the T19007C (rs11615) polymorphism including 910 cases and 1337 controls.

RESULTS

For ERCC1 rs3212986 polymorphism, no significant association with HNSCC was found in overall analysis, but subgroup analysis revealed that a significant association of the rs3212986 polymorphism was found among Asians (A vs. C: OR 0.83; 95% CI 0.70-0.99) but not Caucasians. For ERCC1 rs11615 polymorphism, a significant association with HNSCC (TC + CC vs. TT: OR 1.23; 95% CI 1.03-1.47) was found in overall analysis. Consistently, subgroup analysis revealed that significant associations of the rs3212986 polymorphism were found among Asians (C vs. T: OR 1.32; 95% CI 1.04-1.69) and in laryngeal carcinoma (CC vs. TC + TT: OR 1.32; 95% CI 1.02-1.72).

CONCLUSION

The findings of the meta-analysis indicated that a decreased risk for the ERCC1 rs3212986 polymorphism was found among Asians, and an increased risk for the ERCC1 rs11615 polymorphism was found in overall HNSCC, especially in Asian subgroup and laryngeal site, suggesting that ERCC1 rs3212986 polymorphism in Asians may act as a protective factor and rs11615 polymorphism may be a risk factor for HNSCC.

ERCC1 Cys8092Ala and XRCC1 Arg399Gln polymorphisms predict progression-free survival after curative radiotherapy for nasopharyngeal carcinoma

Background

Single nucleotide polymorphisms (SNPs) in DNA repair genes can alter gene expression and activity and affect response to cancer treatment and, correspondingly, survival. The present study was designed to evaluate the utility of the XRCC1 Arg399Gln and ERCC1 Cys8092Ala SNPs, measured in pretreatment biopsy samples, as predictors of response to radiotherapy in patients with non-metastatic nasopharyngeal carcinoma (NPC).

Materials and methods

The study included 75 consecutive patients with stage II-IVA-B NPC. XRCC1 Arg399Glu and ERCC1 Cys8092Ala SNPs were identified from paraffin-embedded biopsy specimens via Sanger sequencing. Expression of p53 and pAkt protein was analyzed by immunohistochemical staining. Potential relationships between genetic polymorphisms and progression-free survival (PFS) were analyzed by using a Cox proportional hazards model, the Kaplan-Meier method, and the log-rank test.

Results

Multivariate analysis showed that carriers of the ERCC1 8092 Ala/Ala genotype [hazard ratio (HR) 1.882; 95% confidence interval (CI) 1.031–3.438; P = 0.039] and heavy smokers (≥20 pack-years) carrying the XRCC1 Arg/Arg genotype (HR 2.019; 95% CI 1.010–4.036; P = 0.047) had significantly lower PFS rates. Moreover, combined positive expression of p53 and pAkt led to significantly increased PFS in subgroups carrying the XRCC1 Gln allele (HR 7.057; 95% CI 2.073–24.021; P = 0.002) or the ERCC1 Cys allele (HR 2.568; 95% CI 1.056–6.248; P = 0.038).

Conclusions

The ERCC1 Cys8092Ala polymorphism is an independent predictor of response to radiotherapy for NPC, and the XRCC1 Arg399Glu mutation combined with smoking status seems to predict PFS as well. Our results further suggest a possible correlation between these genetic polymorphisms and p53 protein status on survival.

Cell cycle association and hypoxia regulation of excision repair cross complementation group 1 protein (ERCC1) in tumor cells of head and neck cancer

Excision repair cross complementation group 1 (ERCC1) is a key component of homologous recombination-based repair of interstrand DNA cross-links (ICLs). As a consequence, ERCC1 mediates resistance to mitomycin C (MMC) and platinum chemotherapeutic agents and may predict treatment failure. Clinical response to MMC or cisplatin (CDDP)-based radiochemotherapy (RCT) was assessed in 106 head and neck squamous cell carcinoma (HNSCC) patients and correlated with cell nuclear immunoreactivity of the mouse monoclonal (clone: 8 F1) ERCC1 antibody in tumor tissue samples. BEAS-2B epithelial and Detroit 562 pharyngeal squamous carcinoma cells were treated with CDDP, MMC, and 5-fluorouracil (5-FU) at 50 % growth inhibitory (IC-50) concentrations. ERCC1 protein synthesis was compared with cell cycle distribution using combined immunocytochemistry and flow cytometry. ERCC1 messenger RNA (mRNA) and protein expression was investigated in normoxic and hypoxic conditions in Detroit 562 cells. Clinically, the nonresponder revealed significantly lower HNSCC tissue ERCC1 immunoreactivity than the responder (p = 0.0064) or control normal mucosa, which led to further mechanistic investigations. In vitro, control cells and cells treated with cytotoxic agents showed increasing ERCC1 levels from the G1 through S and G2 phases of the cell cycle. In CDDP-treated cells, ERCC1 mRNA and protein expression increased. Under hypoxic conditions, ERCC1 gene expression significantly decreased. Although ERCC1⁺ cells show increased chemoresistance, they might be particularly radiosensitive, representing G2 cell cycle phase and less hypoxic. ERCC1 expression might be indirectly related with some conditions important for RCT treatment, but it is not a clear predictor for its failure in HNSCC patients.

Single-nucleotide polymorphisms in nucleotide excision repair genes, cigarette smoking, and the risk of head and neck cancer

BACKGROUND

Cigarette smoking is associated with increased head and neck cancer (HNC) risk. Tobacco-related carcinogens are known to cause bulky DNA adducts. Nucleotide excision repair (NER) genes encode enzymes that remove adducts and may be independently associated with HNC, as well as modifiers of the association between smoking and HNC.

METHODS

Using population-based case-control data from the Carolina Head and Neck Cancer Epidemiology (CHANCE) Study (1,227 cases and 1,325 controls), race-stratified (White, African American), conventional, and hierarchical logistic regression models were used to estimate ORs with 95% intervals (I) for the independent and joint effects of cigarette smoking and 84 single-nucleotide polymorphisms (SNP) from 15 NER genes on HNC risk.

RESULTS

The odds of HNC were elevated among ever cigarette smokers and increased with smoking duration and frequency. Among Whites, rs4150403 on ERCC3 was associated with increased HNC odds (AA+AG vs. GG; OR, 1.28; 95% CI, 1.01-1.61). Among African Americans, rs4253132 on ERCC6 was associated with decreased HNC odds (CC+CT vs. TT; OR, 0.62; 95% CI, 0.45-0.86). Interactions between ever cigarette smoking and three SNPs (rs4253132 on ERCC6, rs2291120 on DDB2, and rs744154 on ERCC4) suggested possible departures from additivity among Whites.

CONCLUSIONS

We did not find associations between some previously studied NER variants and HNC. We did identify new associations between two SNPs and HNC and three suggestive cigarette-SNP interactions to consider in future studies.

IMPACT

We conducted one of the most comprehensive evaluations of NER variants, identifying a few SNPs from biologically plausible candidate genes associated with HNC and possibly interacting with cigarette smoking.

Molecular epidemiology of DNA repair gene polymorphisms and head and neck cancer

Although tobacco and alcohol consumption are two common risk factors of head and neck cancer (HNC), other specific etiologic causes, such as viral infection and genetic susceptibility factors, remain to be understood. Human DNA is often damaged by numerous endogenous and exogenous mutagens or carcinogens, and genetic variants in interaction with environmental exposure to these agents may explain interindividual differences in HNC risk. Single nucleotide polymorphisms (SNPs) in genes involved in the DNA damage-repair response are reported to be risk factors for various cancer types, including HNC. Here, we reviewed epidemiological studies that have assessed the associations between HNC risk and SNPs in DNA repair genes involved in base-excision repair, nucleotide-excision repair, mismatch repair, double-strand break repair and direct reversion repair pathways. We found, however, that only a few SNPs in DNA repair genes were found to be associated with significantly increased or decreased risk of HNC, and, in most cases, the effects were moderate, depending upon locus-locus interactions among the risk SNPs in the pathways. We believe that, in the presence of exposure, additional pathway-based analyses of DNA repair genes derived from genome-wide association studies (GWASs) in HNC are needed.

ERCC1 and ERCC2 haplotype modulates induced BPDE-DNA adducts in primary cultured lymphocytes

Background

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.

Methods

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.

Results

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.

Conclusions

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.

Nucleotide excision repair gene ERCC1 polymorphisms contribute to cancer susceptibility: a meta-analysis

Individual studies of the associations between excision repair cross-complimentary group 1 (ERCC1) polymorphisms and cancer susceptibility have shown inconclusive results. To derive a more precise estimation of the relationship between three well-characterised polymorphisms on ERCC1 and the risk of cancer, we performed a meta-analysis based on 48 publications. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the associations. We found that ERCC1 17677A (rs3212961) variant genotypes were associated with significantly increased overall risk of cancer without substantial heterogeneity (AA versus CC, OR = 1.36, 95% CIs: 1.10-1.68; AC versus CC: OR = 1.11, 95% CIs: 0.99-1.26; dominant comparison: AA/AC versus CC: OR = 1.15, 95% CIs: 1.02-1.29; recessive comparison: AA versus AC/CC: OR = 1.25, 95% CIs: 1.05-1.49). The ERCC1 19007 C (rs11615) allele had null effects on overall risk of cancer; but in the stratified analyses, we observed an elevated association in Asian populations with homozygote variants and hospital-based controls. In addition, during further stratified analyses of cancer groups, homozygote variants were found that are associated with lung cancer and smoking-related cancers. Also, the observed ERCC1 19007 C heterozygote variant contributes to the development of skin cancer. However, the ERCC1 8092C > A (rs3212986) polymorphism did not appear to have an effect on cancer risk. Additionally, no evidence of publication bias was observed in these polymorphisms. Our meta-analysis supports the conclusion that the ERCC1 17677A > C and ERCC1 19007T > C polymorphisms, but not the ERCC1 8092C > A polymorphism, are low-penetrance risk factors for cancer development.

Pharmacogenetic analyses of cisplatin-induced nephrotoxicity indicate a renoprotective effect of ERCC1 polymorphisms

AIM

We investigated whether genetic polymorphisms may contribute to the interpatient variability of cisplatin-induced nephrotoxicity.

PATIENTS & METHODS

Polymorphisms in the candidate genes GSTM1, GSTT1, OCT1, OCT2, LARP2, ERCC1, XRCC1 and EPO were analyzed for associations with nephrotoxicity in 79 cancer patients receiving cisplatin-containing chemotherapy.

RESULTS

Higher cisplatin dose was associated with strongly decreased estimated glomerular filtration rates (eGFR) (r(2) = 0.205). Two highly genetically linked polymorphisms in the ERCC1 gene, 8092C>A and Asn118Asn, were significantly associated with change in eGFR, accounting for an additional 13% of interindividual variability. Homozygous carriers of the 8092A allele in ERCC1 showed no reduction in eGFR, compared with the 11.5% mean eGFR decrease in C allele carriers (p = 0.004). Homozygous carriers of the C allele of Asn118Asn showed no reduction in eGFR, compared with the 12.8% mean eGFR decrease seen in T allele carriers (p = 0.047). Polymorphisms in the other candidate genes were not associated with cisplatin-induced nephrotoxicity.

CONCLUSION

Genetic polymorphisms in ERCC1 may be valuable predictors of cisplatin-induced nephrotoxicity.

ERCC1 and XRCC1 as biomarkers for lung and head and neck cancer

Advanced stage non-small cell lung cancer and head and neck squamous cell carcinoma are both treated with DNA damaging agents including platinum-based compounds and radiation therapy. However, at least one quarter of all tumors are resistant or refractory to these genotoxic agents. Yet the agents are extremely toxic, leading to undesirable side effects with potentially no benefit. Alternative therapies exist, but currently there are no tools to predict whether the first-line genotoxic agents will work in any given patient. To maximize therapeutic success and limit unnecessary toxicity, emerging clinical trials aim to inform personalized treatments tailored to the biology of individual tumors. Worldwide, significant resources have been invested in identifying biomarkers for guiding the treatment of lung and head and neck cancer. DNA repair proteins of the nucleotide excision repair pathway (ERCC1) and of the base excision repair pathway (XRCC1), which are instrumental in clearing DNA damage caused by platinum drugs and radiation, have been extensively studied as potential biomarkers of clinical outcomes in lung and head and neck cancers. The results are complex and contradictory. Here we summarize the current status of single nucleotide polymorphisms, mRNA, and protein expression of ERCC1 and XRCC1 in relation to cancer risk and patient outcomes.

Polymorphisms in DNA damage response genes and head and neck cancer risk

BACKGROUND

Polymorphisms in DNA repair genes have been reported contributing factors in head and neck cancer risk but studies have shown conflicting results.

OBJECTIVE

To clarify the impact of DNA repair gene polymorphisms in head and neck cancer risk.

METHOD

A meta-analysis including 30 case-control studies was performed.

RESULTS

Marginally statistically significant association was found for XRCC1 codon 399 (for Caucasians only), XPD Asp312Asn and XRCC1 codon 194 variants and head and neck cancer.

CONCLUSION

Assessments of the effects of smoking, alcohol, human papillomavirus and race/ethnicity on the association between DNA repair gene polymorphisms and head and neck cancer are needed.

Cox-2 and IL-10 polymorphisms and association with squamous cell carcinoma of the head and neck in a Korean sample

Cyclooxygenase-2 (COX-2) is involved in inflammation and carcinogenesis. Interleukin-10 (IL-10) is also regarded as anti-inflammatory factors with the multi-functional ability to positively and negatively influence functional immunity and tumor development. Genetic polymorphisms of COX-2 and IL-10 might contribute to the development of squamous cell carcinoma of the head and neck (SCCHN). The purpose of this study was to evaluate the association of COX-2 and IL-10 single nucleotide polymorphisms (SNPs) with the risk of SCCHN in a Korean sample. We analyzed the COX-2 SNPs, -1329A>G, +1266C>T, and +6365T>C, and the IL-10 SNPs, -1082A>G, +920T>G, and +3917T>C, in 290 Korean SCCHN patients and 358 healthy controls. There was no significant association between the risk of SCCHN and the three COX-2 or three IL-10 SNPs. We analyzed three haplotypes (ht1, ht2, ht3) for COX-2 and found that COX-2 ht3+/+ was associated with a decreased risk of SCCHN in a Korean sample, compared with the COX-2 ht3 -/- genotype (P=0.03). Two haplotypes (ht1, ht2) of IL-10 were analyzed and there was no statistical significance in the distribution of haplotypes. Based on these results, the COX-2 haplotype ht3 can be used as a molecular biomarker to predict low risk groups of SCCHN in a Korean sample.

XPD Polymorphisms and Risk of Squamous Cell Carcinoma of the Head and Neck in a Korean Sample

Objectives

XPD is a major player in nucleotide excision repair, which is one of the basic pathways of DNA repair. The objective of this study was to investigate the association of XPD single nucleotide polymorphisms (SNPs) and the risk of squamous cell carcinoma of the head and neck (SCCHN) in Koreans.

Methods

We performed XPD +23591G>A and +35931A>C genotyping in 290 SCCHN patients and 358 controls.

Results

The frequencies of the XPD +23591G>A (GG/GA/AA) genotypes were 89.0%/11.0%/0% in the patients and 90.3%/8.8%/0.9% in the controls, respectively. The odds ratio (OR) of the XPD +23591 GA genotype was 1.94 (0.92 to 4.08) in reference to the GG genotype. The frequencies of the XPD +35931A>C (AA/AC/CC) genotypes were 86.9%/12.0%/1.1% in the patients and 85.6%/13.8%/0.6% in the controls, respectively. The OR of the XPD +35931 AC and CC genotypes were 0.98 (0.51 to 1.88) and 2.68 (0.71 to 10.1), respectively, in reference to the AA genotype. On the subgroup analyses according to the smoking and drinking statuses, the SNPs and haplotypes of XPD showed no statistically significant association with the risk of SCCHN.

Conclusion

The results of this study suggest that the XPD +23591G>A and +35931A>C SNPs are not associated with the risk of SCCHN in Koreans; however, a further study with a larger number of subjects is necessary to verify this conclusion.

CASP3 polymorphisms and risk of squamous cell carcinoma of the head and neck

PURPOSE

Caspase-3 plays a central role in executing cell apoptosis and thus in carcinogenesis, but little is known about the role of CASP3 variants in susceptibility to SCCHN.

EXPERIMENTAL DESIGN

Genotype and haplotypes of the first intron (rs4647601:G>T and rs4647602:C>A) and 5'-untranslated region (UTR; rs4647603:G>A) of CASP3 (NT_022792.17) were determined for 930 SCCHN patients and 993 cancer-free controls in a U.S. non-Hispanic white population. Odds ratio (OR) and 95% confidence interval (95% CI) were calculated in multivariate logistic regression analysis.

RESULTS

We found that the CASP3 rs4647601:TT variant genotype was associated with an increased risk of SCCHN (adjusted OR, 1.32; 95% CI, 1.00-1.73) compared with the GG genotype. This risk was more evident in the subgroups of younger (< or =56 years) subjects, males, and never smokers with a significant trend for increased risk with increased number of variant T allele (P < 0.05 for all). However, these risks were not found for other two SNPs. Furthermore, individuals with two copies of haplotypes TCG or GCA were found to have a significant increased risk of SCCHN (OR, 1.31; 95% CI, 1.07-1.61) compared with the other haplotypes, and this risk was more evident in less advanced diseases (OR, 1.45; 95% CI, 1.11-1.89) than in the advanced diseases (OR, 1.22; 95% CI, 0.96-1.54).

CONCLUSIONS

These results suggested that genetic variation in CASP3 may contribute to SCCHN risk. Larger studies are needed to confirm our findings.

A distinct ERCC1 haplotype is associated with mRNA expression levels in prostate cancer patients

Both genetic variants and messenger RNA (mRNA) expression of DNA repair and tumor suppressor genes have been investigated as molecular markers for therapy outcome. However, the phenotypic impact of genetic variants often remained unclear, thus the rationale of their use in risk prediction may be limited. We therefore analyzed genetic variants together with anthropometric and lifestyle factors to see how these affect mRNA levels of ERCC1 , MDM2 and TP53 in primary blood lymphocytes. mRNA expression was measured in 376 prostate cancer patients by quantitative real-time polymerase chain reaction after reverse transcription, and ERCC1 rs11615 T>C, ERCC1 rs3212986 C>A, MDM2 rs2279744 T>G and TP53 rs17878362 (p53PIN3) polymorphisms were determined. Considerable interindividual differences in mRNA expression were found (coefficients of variation: ERCC1 , 45%; MDM2 , 43% and TP53 , 35%). ERCC1 expression was positively correlated with plasma levels of β-carotene ( P  = 0.03) and negatively correlated with canthaxanthin ( P  = 0.02) and lutein ( P  = 0.02). Overall, the polymorphisms affected mRNA expression only weakly. Carriers of a distinct ERCC1 haplotype (CC) showed, however, significantly lower expression values than non-carriers ( P  = 0.001). Applying logistic regression, we found that CC haplotype carriers had a 1.69-fold increased odds ratio (95% confidence interval: 1.06–2.71) for reduced ERCC1 mRNA levels. This low ERCC1 expression might be associated with reduced DNA repair and better therapy response. In summary, the association we have found between ERCC1 genotype and mRNA expression supports recent clinical observations that genetic variation in ERCC1 can affect treatment outcome and prognosis. Our study further revealed a modulating effect by nutritional factors.

Current status of excision repair cross complementing-group 1 (ERCC1) in cancer

Cisplatin, carboplatin and oxaliplatin are some of the most widely used anti-cancer agents in solid tumours. The cytotoxicity of platinating agents is directly related to their ability to cause DNA intra-strand crosslinks that trigger a series of intracellular events that ultimately result in cell death. DNA intra-strand crosslinks are processed and repaired by the nucleotide excision repair pathway. It is now clear that nucleotide excision repair (NER) capacity may have a major impact on the emergence of resistance, normal tissue tolerance and patient outcomes. ERCC1 is a key player in NER. In this review, we provide an overview of mammalian NER and then focus on biochemical, structural and pre-clinical aspects of ERCC1. We then present current clinical evidence implicating ERCC1 as a predictive and prognostic marker in cancer. Early evidence also suggests that ERCC1 or the pathways involved in the regulation of ERCC1 expression may be attractive anti-cancer targets. Such agents are expected to potentiate the cytotoxicity of platinating agents and could have a major impact on cancer therapy.

No association of ERCC1 C8092A and T19007C polymorphisms to cancer risk: a meta-analysis

ERCC1 (excision repair cross complementation group 1) is a subunit of the nucleotide excision repair complex, which can perform DNA strand incision correction of DNA damage. Association studies on the ERCC1 polymorphisms (C8092A and T19007C) in cancer had shown conflicting results. We performed a meta-analysis from all eligible case-control studies to assess the purported associations. Overall, the 19007C allele (3 853 patients and 4 349 controls) showed no significant effect on cancer risk compared to 19007T allele (P=0.39, odds ratio (OR)=0.95; 95% confidence interval (CI) 0.85-1.06, P(heterogeneity)=0.001) in all subjects. Meta-analysis under other genetic contrasts did not reveal any significant association of T19007C to cancer in all subjects, Caucasians and Asians. The 19007C allele (2 279 patients and 2 808 controls) showed no significant effect on lung cancer risk compared to 19007T allele (P=0.72, OR=0.94, 95% CI 0.69-1.29, P(heterogeneity)=0.0001) in all subjects. No significant effect of 8092A allele (3 865 patients and 3 750 controls) on cancer risk in all subjects (P=0.85, OR=1.01, 95% CI 0.94-1.08, P(heterogeneity)=0.92) and in Caucasians and Asians compare to 8092C. No evidences of association of C8092A (501 patients and 620 controls) to squamous cell carcinoma were found. The accumulated evidence indicated ERCC1 T19007C and C8092A might not be risk factors for cancer. Significant between-study heterogeneity existed in T19007C, which arose from a study showing significant protecting effect of 19007C allele compare to 19007T allele in smokers. More studies based on larger, stratified case-control population should be required to further evaluate the role of ERCC1 C8092A and T19007C polymorphisms in different cancer, especially in smokers.