Pharmacogenetic role of ERCC1 genetic variants in treatment response of platinum-based chemotherapy among advanced non-small cell lung cancer patients

The excision repair cross-complementation group 1 (ERCC1) plays an essential role in DNA repair and has been linked to resistance to platinum-based anticancer drugs among advanced non-small cell lung cancer (NSCLC) patients. We systematically evaluate whether ERCC1 Asn118Asn and C8092A genetic variants are associated with treatment response of platinum chemotherapy. We preformed a meta-analysis using ten eligible cohort studies (including 11 datasets) with a total of 1,252 NSCLC patients to summarize the existing data on the association between the ERCC1 Asn118Asn and C8092A polymorphisms and response to platinum regiments. Odds ratio or hazard ratio with 95% confidence interval were calculated to estimate the correlation. We found that neither ERCC1 C8092A polymorphism nor Asn118Asn variant is associated with different response of platinum-based treatment among advanced NSCLC patients. Additionally, these two genetic variants are not related to treatment response in either Caucasian patients or Asian patients. Our meta-analysis indicates that the ERCC1 Asn118Asn and C8092A polymorphisms may not be good prognostic biomarkers for platinum-based chemotherapy in patients with stage III-IV NSCLC.     

核苷酸还原酶亚单位M1和内切修复交叉补体1在非小细胞肺癌中的研究进展

核苷酸还原酶亚单位M1（RRM1）属抑癌基因，RRM1可以激发G2期检测点功能，使受损的DNA得以修复或者发生凋亡，并具有抑制细胞侵袭和转移的作用，另外RRM1还可以调节核苷酸还原酶的活性，是抗代谢药吉西他滨作用的靶分子，RRM1高表达的细胞对吉西他滨耐药。内切修复交叉补体1（ERCC1）是细胞内负责修复受损DNA的核苷酸内切修复通路中的限速酶，可以识别和去除铂-DNA附加物而导致细胞对铂类耐药。本文综述RRM1和ERCC1在非小细胞肺癌患者预后和化疗个体化方面的研究进展。     

ERCC1 Expression in Metastatic Triple Negative Breast Cancer Patients Treated with Platinum-Based Chemotherapy

Background: Possible targeted therapies for metastatic triple negative breast cancer (TNBC) include cytotoxic chemotherapy that causes interstrand breaks (platinum-based drugs). The excision repair cross-complementation 1 (ERCC1) enzyme plays an essential role in the nucleotide excision repair pathway, removing platinum-induced DNA adducts and contributing to cisplatin resistance. Detecting ERCC1 overexpression is important in considering treatment options for metastatic TNBC, including individualized approaches to therapy, and may facilitate improved responses or reduction of unnecessary toxicity. We hypothesized that assigning cisplatin based on pretreatment ERCC1 expression would improve response and survival. This study was conducted to assess the impact of ERCC1 expression on PFS, OS and response rates in metastatic triple negative breast cancer patients treated with platinum-based chemotherapy. Methods: From June 2012 to November 2013, 52 metastatic triple negative breast cancer patients were enrolled. ERCC1 protein expression was detected from pretreatment biopsies by Immunohistochemistry. All patients received cisplatin plus paclitaxel. The primary end point was the impact of ERCC1 expression on PFS and OS. Results: 34 patients (65.4%) showed positive ERCC1 expression while 18 (34.6%) proved negative. Positive ERCC1 expression was associated with short PFS (median, 5 months vs. 7 months; P = 0.043), short OS (median, 9 months vs. 11 months; P = 0.033) and poor response to cisplatin based chemotherapy (P = 0.046). Conclusions: This prospective study further validated ERCC1 as a reliable biomarker for customized chemotherapy in metastatic triple negative breast cancer patients. High expression of ERCC1 was thereby fond to be significantly associated with poor outcome in patients treated with platinum based chemotherapy.     

Effect of the ERCC1 (C118T) Polymorphism on Treatment Response in Advanced Non-Small Cell Lung Cancer Patients Undergoing Platinum-Based Chemotherapy

For advanced non-small-cell lung cancer (NSCLC) cases, a platinum-based regimen is the first-line chemotherapy treatment. The excision repair cross-complementing group 1 (ERCC1) plays an important role in DNA repair and has been related to resistance to platinum chemotherapy. This study aimed to investigate the effects of the ERCC1 (C118T) polymorphism on treatment response in 26 Thai advanced NSCLC patients receiving first line platinum-based chemotherapy during January to July 2015 at King Chulalongkorn Memorial Hospital (KCMH). DNA was extracted from peripheral blood lymphocytes and the single nucleotide polymorphism of ERCC1 was genotyped using a real-time PCR method with the TaqMan assay. The distribution of C/C, C/T and T/T genotypes was 57.7 %, 34.6 % and 7.7 %, respectively. The response rate to platinum-based chemotherapy in the wild type (C/C) of ERCC1 (C118T) was better than with the variant types (C/T and T/T) but the difference was not statistically significant (29.7% vs 9.1%, P=0.274). The results showed that a genetic polymorphism in ERCC1 might influence patient response to platinum-based chemotherapy. Further multicenter studies are now required to confirm the results of our study.     

DNA repair gene polymorphism associated with sensitivity of lung cancer to therapy

This study aimed to investigate association between single-nucleotide polymorphisms (SNPs) of excision repair cross-complementing gene 1 (ERCC1), excision repair cross-complementing gene 2 (ERCC2), and X-ray repair cross-complementing group 1 (XRCC1) with sensitivity of advanced non-small cell lung cancer (NSCLC) patients to platinum-based chemotherapy. A total of 89 NSCLC patients were recruited and treated with two cycles of platinum-based chemotherapy. DNA was extracted from peripheral lymphocytes for detection of SNPs of ERCC1 Asn118Asn, ERCC2 Lys751Gln, and XRCC1 Arg399Gln. The overall response rate of these patients was 29.2%. There was no statistically significant difference of treatment response between the wild genotypes and the variant genotypes for the ERCC1 Asn118Asn and ERCC2 Lys751Gln gene. The distributions of genotypes XRCC1 Arg399Gln differed significantly between the response and non-response groups (76.9 vs. 23.1%, P = 0.001). The XRCC1 399Arg/Arg genotype carriers had a higher response rate than that of the Gln genotype carriers (OR = 4.81, 95%CI = 1.778-13.013, P = 0.002). The combination of the favorable genotypes of ERCC1, ERCC2, and XRCC1 had a higher response rate compared to that of patients with other genotypes. The combined polymorphisms of ERCC1, ERCC2, and XRCC1 may be associated with sensitivity of NSCLC to platinum-based chemotherapy. Further studies will verify these SNPs as biomarkers for prediction of platinum-based chemotherapy responses of NSCLC patients.     

Multiple roles of the ERCC1-XPF endonuclease in DNA repair and resistance to anticancer drugs

In this review, we focus on the discrepant roles of the DNA repair complex ERCC1/XPF in the prevention of cancer and in the resistance of cancer to chemotherapy. ERCC1/XPF is essential for nucleotide excision repair (NER) incising DNA 5' to the lesion. NER deficiency results in the skin cancer-prone inherited disease xeroderma pigmentosum (XP). The ERCC1/XPF complex is also involved in recombination, double strand break (DSB) and interstrand crosslink (ICL) repair cutting DNA overhangs around a lesion. In telomere maintenance ERCC1/XPF degrades 3' G-rich overhangs. In some types of cancer, high levels of ERCC1/XPF mRNA and protein correlate with poor overall survival and resistance to platinum-based chemotherapeutic treatments. Therefore, the ERCC1/XPF complex makes an attractive target for prediction of outcome for treatment in cancer patients as well as a novel drug target.     

ERCC1新抗体在非小细胞肺癌铂类用药分子诊断中的应用

背景与目的：DNA切除修复交叉互补基因1(excision repair cross complementation group l,ERCC1)的高表达与铂类药物的耐药性相关。以往研究中常采用ERCC1抗体8F1,近来发现其有非特异性。为了检测ERCC1新抗体4F9在非小细胞肺癌(non-small cell lung cancer,NSCLC)铂类用药的指导作用。方法：采用免疫组化法对72例NSCLC患者肿瘤组织进行ERCC1检测,分析患者的ERCC1蛋白表达与临床特征、铂类为基础化疗方案的疗效及患者生存期的关系。结果：72例NSCLC组织中ERCC1蛋白高表达者占55.5％。ERCC1的蛋白表达与患者的性别、年龄、组织学类型、临床分期、淋巴结转移均无明显相关性(P>0.05);ERCC1低表达患者的化疗有效率、中位生存期及2年生存率均高于高表达患者(62.5％ vs 37.5％;22.9 vs 18.4个月;46.9％vs 37.5％),差异均有统计学意义(P<0.05)。结论：ERCC1新抗体4F9免疫组化法检测ERCCl的表达有助于筛选NSCLC患者辅助化疗方案,指导患者术后铂类药物的个体化治疗。     

Platinum resistance: the role of DNA repair pathways.

Although platinum chemotherapeutic agents such as carboplatin, cisplatin, and oxaliplatin are used to treat a broad range of malignant diseases, their efficacy in most cancers is limited by the development of resistance. There are multiple factors that contribute to platinum resistance but alterations of DNA repair processes have been known for some time to be important in mediating resistance. Recently acquired knowledge has provided insight into the molecular mechanisms of DNA repair pathways and their effect on response to chemotherapy. This review will discuss the most important DNA repair pathways known to be involved in the platinum response, i.e., nucleotide excision repair (NER) and mismatch repair (MMR), and will briefly touch on the role of BRCA in DNA repair. The therapeutic implications of alterations in DNA repair which affect response to platinum in the treatment of patients with malignant disease, such as excision repair cross-complementation group 1 (ERCC1) deficiency and mismatch repair deficiency, will be reviewed.     

ERCC1 and RRM1 gene expressions but not EGFR are predictive of shorter survival in advanced non-small-cell lung cancer treated with cisplatin and gemcitabine.

BACKGROUND: Pivotal studies indicate a role of excision repair cross-complementation 1 (ERCC1) gene and ribonucleotide reductase M1 (RRM1) gene in conferring a differential sensitivity to cytotoxic chemotherapy and epidermal growth factor receptor (EGFR) gene has been recently extensively investigated in non-small-cell lung cancer (NSCLC). DESIGN: Formalin-fixed, paraffin-embedded bronchoscopic/fine needle aspiration biopsies obtained from 70 patients with advanced NSCLC were retrospectively collected to investigate the expression level of ERCC1, RRM1 and EGFR by real-time PCR. Sufficient amounts of messenger RNA (mRNA) were successfully extracted from 61 (87%) specimens, reverse transcribed and amplified with intron-spanning primers. Forty-one patients had stage IV disease and 43 received cisplatin/gemcitabine chemotherapy. RESULTS: A strong correlation between ERCC1 and RRM1 mRNA levels (r(s) = 0.624, P < 0.0001) was found. Median survival time in patients with low ERCC1 was significantly longer (17.3 versus 10.9, P = 0.0032 log-rank test) as well as in patients with low RRM1 (13.9 versus 10.9, P = 0.0390 log-rank test). Concomitant low expression levels of ERCC1 and RRM1 (n = 33) were predictive of a better outcome (14.9 versus 10.0, P = 0.0345 log-rank test). Among cisplatin-treated patients, a low ERCC1 level was highly predictive of a longer survival (23.0 versus 12.4, P = 0.0001 log-rank test). No correlation between gene expression levels and histology was reported. No significant correlation between EGFR expression level and survival was found. At multivariate analysis, performance status, response to chemotherapy, presence of weight loss and ERCC1 were independent prognostic factors for survival. CONCLUSIONS: This retrospective study further validates ERCC1 and RRM1 genes as reliable candidates for customized chemotherapy and shows a higher impact on the survival of NSCLC patients treated with cisplatin/gemcitabine for ERCC1. Prospective pharmacogenomic studies represent a research priority in early and advanced NSCLC.     

核苷酸切除修复系统基因遗传多态与晚期非小细胞肺癌患者铂类药物敏感性关系

背景与目的:肿瘤细胞对铂类药物的化疗敏感性与个体的DNA损伤修复能力关系密切,本研究探讨核苷酸切除修复系统(nucleotideexcisionrepair,NER)的重要成员XPC、XPD和ERCC1基因的遗传多态与晚期非小细胞肺癌(non-smallcelllungcancer,NSCLC)患者对铂类药物敏感性的关系。方法:对接受含铂类药物化疗的200例晚期NSCLC患者进行临床疗效评价。以聚合酶链-扩增片段长度多态性(PCR-AFLP)和限制性片段长度多态性(RFLP)的方法检测XPC-PAT、XPDLys751Gln(rs1052559)和ERCC1C8092A(rs1052559)多态的基因型,比较不同基因型与化疗敏感性的关系。结果:结合疗效情况,XPC-PAT遗传多态各基因型在化疗有效组(CR PR)和无效组(SD PD)中的分布频率差异有显著性(!2检验,P=0.023),携带XPCLL基因型个体的化疗敏感性是XPCSS基因型携带者的3.04倍(95%CI为1.25～7.41,P=0.015)。没有发现XPDLys751Gln和ERCC1C8092A多态与化疗敏感性的相关性。但联合分析后发现,核苷酸切除修复系统的这三个遗传多态在晚期NSCLC患者对铂类药物敏感性中存在一定的联合作用(趋势检验,P=0.021)。结论:核苷酸切除修复系统中XPC-PAT、XPDLys751Gln和ERCC1C8092A遗传多态可能与NSCLC患者对铂类药物敏感性相关。     

核苷酸切除修复交叉互补基因1 mRNA表达与非小细胞肺癌铂类化疗患者预后的相关性

目的 探讨核苷酸切除修复交叉互补基因1(ERCC1)mRNA表达与非小细胞肺癌(NSCLC)铂类化疗患者临床病理特征的关系及其预后意义.方法 采用实时荧光定量逆转录聚合酶链反应(RT-PCR)方法,检测NSCLC石蜡包埋组织中ERCC1 mRNA的表达水平,并比较其表达水平与NSCLC铂类化疗患者临床病理特征和生存时间之间的关系.结果 61例NSCLC患者中,ERCC1 mRNA的中位表达量为0.48.ERCC1 mRNA表达与NSCLC患者临床病理特征无关.ERCC1mRNA低表达(<0.35)患者经铂类药物化疗后的无进展生存时间为14.3个月,而高表达者为8.0个月,差异有统计学意义(P=0.028).ERCC1 mRNA低表达(<0.28)患者的总生存时间为28.4个月,而高表达者为12.9个月,差异有统计学意义(P=0.0064).Cox多因素回归分析显示,ERCC1 mRNA表达水平是影响NSCLC患者预后的独立因素.结论 ERCC1 mRNA的表达水平可以作为以铂类为基础药物化疗的NSCLC患者预后的独立预测因素,ERCC1 mRNA低表达的NSCLC患者经铂类化疗后,总生存时间明显延长,为制定NSCLC个体化的化疗方案提供了重要信息.     

A review of excision repair cross-complementation group 1 in colorectal cancer

Oxaliplatin-based chemotherapy is the standard of care in patients with high-risk stage II and stage III colorectal cancer as well as in patients with advanced disease. Unfortunately, a large proportion of patients offered oxaliplatin fail to benefit from it. In the era of personalized treatment, there are strong efforts to identify biomarkers that will predict efficacy to oxaliplatin-based treatments. Excision repair cross-complementation group 1 (ERCC1) is a key element in the nucleotide excision repair (NER) pathway, which is responsible for repairing DNA adducts induced by platinum compounds. ERCC1 has recently been shown to be closely associated with outcome in patients with non–small-cell lung cancer (NSCLC): both high ERCC1 protein and gene expression are associated with resistance to cisplatin-based chemotherapy and better outcome without treatment. Therefore, ERCC1 has the potential to be used as a strong candidate biomarker, both predictive and prognostic, for colorectal cancer. This review will focus on the preclinical and clinical evidences supporting ERCC1 as a major molecule in oxaliplatin resistance. In addition, the important technologies used to assess ERCC1 gene and protein expression will be highlighted.     

Role of ERCC1 variants in response to chemotherapy and clinical outcome of advanced non-small cell lung cancer

Excision repair cross-complementation group 1 (ERCC1) and xeroderma pigmentosum-F (XPF) in the nucleotide excision repair pathway have been effectively repairing DNA damage induced by chemotherapeutic agents. We conducted a cohort study to assess the associations of ERCC1 and XPF polymorphisms with response to platinum-based chemotherapy and clinical outcome of non-small-cell lung cancer (NSCLC). One hundred eighty-seven NSCLC cases treated with platinum-based chemotherapy were prospectively analyzed. The predictive value of four SNPs in ERCC1 and two SNPs in XPF in patient's response and survival related to platinum-based chemotherapy were analyzed using χ ² tests, Kaplan-Meier method, log-rank test, and Cox proportional hazards regression. The overall chemotherapy response rate for treatment was 51.18 %. One hundred eighty-seven patients were followed up, and the median survival time is 17.6 months (ranged from 1 to 50 months). A total of 106 patients (56.68 %) died from NSCLC during the follow-up period. Carriers of the rs3212986 AA and A allele had a borderline significantly lower response rate to the chemotherapy. In the Cox proportional hazards model, patients carrying the ERCC1 rs3212986 AA genotype were significantly associated with increased risk of death from NSCLC when compared with those with CC genotype as a reference variable. This study reported that variants in ERCC1 can be used as a prognostic maker to platinum-based chemotherapy in NSCLC patients.     

ERCC1和XRCC1多态性与进展期非小细胞肺癌对铂类化疗的敏感性

目的探讨DNA修复基因ERCC1 118C/T和XRCC1 Arg194Trp多态性与进展期非小细胞肺癌(non-small cell lung cancer,NSCLC)患者铂类药物化疗敏感性的关系。方法采用PCR-RFLP技术检测149例经病理确诊的接受含铂两药方案化疗的NSCLC患者外周血ERCC1 118和XRCC1 194位点的基因型,并分析其与化疗疗效的关系。结果经2个周期化疗后,149例进展期NSCLC患者化疗有效率为32.9%。携带至少1个ERCC1 118T突变基因患者的化疗有效率至少是C/C野生型基因携带者的3倍(49.1%vs 23.4%,OR=3.156,95%CI:1.548～6.334,P=0.001)。携带至少1个XRCC1 194Trp突变基因患者的化疗有效率显著高于Arg/Arg基因型携带者(41.3%vs 23.2%,OR=2.326,95%CI:1.138～4.753,P=0.019)。ERCC1 118C/T和XRCC1 Arg194Trp 2个基因多态之间存在一定的联合作用,携带至少1个ERCC1 118 T突变基因同时又携带至少1个XRCC1 194Trp突变基因型者的化疗有效率明显高于同时携带ERCC1 118C/C和XRCC1 194Arg/Arg野生型基因者(66.7%vs 17.1%,OR=9.714,95%CI:3.104～30.406,P<0.001)。结论与单基因检测比较,2个基因的联合检测在预测铂类药物化疗敏感性中的价值更大。ERCC1 118和XRCC1 194基因多态联合与NSCLC患者对铂类药物化疗敏感性相关,ERCC1和XRCC1基因型的联合检测有可能成为预测铂类药物化疗敏感性的指标。     

晚期非小细胞肺癌中ERCC1蛋白表达与铂类化疗药物敏感性的关系

目的探讨晚期非小细胞肺癌（NSCLC）中核苷酸切除修复交叉互补基因（ERCC1）的表达及其与铂类化疗药物疗效的相关性。方法采用免疫组化S-P法,检测69例Ⅲ、Ⅳ期非小细胞肺癌中ERCC1蛋白表达。所有患者采用以铂类为基础的方案化疗。结果 69例晚期NSCLC组织中ERCC1蛋白表达阳性率为39.13%（27/69）,鳞癌为41.94%（13/31）,腺癌为36.84%（14/38）,ERCC1蛋白表达阳性率与肿瘤组织学类型无关（χ2=0.1859,P=0.6663）。鳞癌患者ERCC1蛋白表达阴性者化疗有效率为44.44%,ERCC1阳性者化疗有效率为7.69%,两者比较差异有统计学意义（P=0.0448）;腺癌患者ERCC1表达阴性者化疗有效率为33.33%,ERCC1表达阳性者化疗有效率为21.43%,两者比较差异无统计学意义（P=0.4882）。不论鳞癌还是腺癌患者,ERCC1表达对患者生存期均无明显影响（P均〉0.05）。结论 ERCC1蛋白表达与晚期NSCLC患者的化疗疗效密切相关,尤其是鳞癌患者。     

ERCC1和XPD单核苷酸多态性与非小细胞肺癌铂类化疗敏感性的关系

目的：探讨DNA修复基因ERCC1 C118T和XPD Lys751Gln单核苷酸多态性与非小细胞肺癌（non-small-cell lung carcinoma,NSCLC）患者对含铂方案化疗敏感性的关系。方法：选择经病理确诊为NSCLC的患者73例,在实施化疗前采取静脉血,提取DNA,行DNA测序、用PCR-RFLP方法检测ERCC1 C118T和XPD Lys751Gln基因型。所有患者均经含铂方案化疗,观察疗效,统计临床获益率,分析NSCLC患者ERCC1和XPD单核苷酸多态性与含铂方案化疗敏感性的关系。结果：ERCC1 C118TC/C、C/T和T/T基因型临床获益率分别为94.9%、71.4%和83.8%。基因型C/C临床获益率明显高于C/T、T/T（P〈0.05）。XPD Lys751Gln基因型Lys/Lys、Lys/Gln临床获益率分别为80.3%和75.0%。基因型Lys/Lys与Lys/Gln临床获益率间的差异无统计学意义（P=0.702）。未检测到XPD Gln/Gln基因型。ERCC1 C118T、XPD Lys751Gln多态之间在对含铂方案的化疗敏感性方面无协同作用（P=0.134和P=0.236）。结论：DNA修复基因ERCC1 C118T单核苷酸多态性与NSCLC含铂方案化疗的敏感性有关,可作为预测NSCLC患者铂类药物化疗敏感性的参考指标之一。     

Excision repair cross-complementation group 1 polymorphism predicts overall survival in advanced non-small cell lung cancer patients treated with platinum-based chemotherapy.

DNA repair is a critical mechanism of resistance to platinum-based chemotherapy. Excision repair cross-complementation group 1 (ERCC1) is the lead enzyme in the nucleotide excision repair process. Increased ERCC1 mRNA levels are related directly to platinum resistance in various cancers. We examined the association between two polymorphisms of ERCC1, codon 118 C/T and C8092A, which are associated with altered ERCC1 mRNA levels and mRNA stability, and overall survival (OS) in 128 advanced non-small cell lung cancer patients treated with platinum-based chemotherapy. The two polymorphisms were in linkage disequilibrium. There was a statistically significant association between the C8092A polymorphism and OS (P = 0.006, by log-rank test), with median survival times of 22.3 (C/C) and 13.4 (C/A or A/A) months, respectively, suggesting that any copies of the A allele were associated with poor outcome. No statistically significant association was found for the codon 118 polymorphism and OS (P = 0.41, by log-rank test), with median survival times of 19.9 (T/T), 16.1 (C/T), and 13.3 (C/C) months, respectively. In conclusion, the ERCC1 C8092A polymorphism may be a useful predictor of OS in advanced non-small cell lung cancer patients treated with platinum-based chemotherapy.