Excision Repair Cross-complementing Research Articles

Analysis of ERCC1, BRCA1, RRM1 and TUBB3 as predictors of prognosis in patients with non-small cell lung cancer who received cisplatin-based adjuvant chemotherapy: A prospective study.

Although adjuvant platinum-based chemotherapy has been demonstrated to improve survival in patients with completely resected non-small cell lung cancer (NSCLC), individualized approaches to therapy are urgently required to improve the treatment efficacy and reduce unnecessary toxicity. It was hypothesized in the present study that the protein levels of excision repair cross-complementation group 1 (ERCC1), breast cancer 1 (BRCA1), ribonucleotide reductase M1 (RRM1) and class III β-tubulin (TUBB3) may influence the therapeutic effect of adjuvant cisplatin-based chemotherapy. The expression of ERCC1, BRCA1, RRM1 and TUBB3 in tissues obtained from 84 patients with NSCLC was analyzed in the present non-interventional study by immunohistochemistry prior to adjuvant chemotherapy. All patients received adjuvant cisplatin-based chemotherapy. The primary endpoint in the present study was disease free survival (DFS). Out of the 84 tumors, the expression of ERCC1, BRCA1, RRM1 and TUBB3 was identified in 46 (55%), 11 (13%), 73 (87%) and 76 (90%) tissues, respectively. A beneficial response to adjuvant cisplatin-based chemotherapy in DFS was associated with the absence of the expression of ERCC1 [hazard ratio (HR), 2.166; 95% confidence interval (CI), 1.049-4.474; P=0.037] and BRCA1 (HR, 2.419; 95% CI, 1.127-5.193; P=0.023), but not with the expression status of RRM1 (HR, 0.568; 95% CI, 0.234-1.379; P=0.212) or TUBB3 (HR, 1.874; 95% CI, 0.448-7.842; P=0.39). In addition, patients lacking the expression of ERCC1 and BRCA1 benefited more from adjuvant cisplatin-based chemotherapy compared with patients that expressed either ERCC1 or BRCA1 (HR, 3.102; 95% CI, 1.343-7.163; P=0.008). The expression of ERCC1 and BRCA1 was significantly associated with the DFS time in patients with NSCLC treated with adjuvant cisplatin-based chemotherapy, respectively. The combination of the ERCC1 and BRCA1 expression levels may be a promising prognostic prediction for adjuvant cisplatin-based chemotherapy.

Overexpression of Excision Repair Cross Complementing-1 Gene May Predict Local Recurrence After Definitive Chemoradiation for Unresectable Non-Small Cell Lung Cancer

Overexpression of Excision Repair Cross Complementing-1 Gene May Predict Local Recurrence After Definitive Chemoradiation for Unresectable Non-Small Cell Lung Cancer

Factors affecting platinum sensitivity in cervical cancer.

The present study aimed to investigate the association between nedaplatin (NDP) sensitivity and the expression of biological factors in cervical cancer. A total of 45 cervical cancer specimens, including 18 pretreatment biopsies and 27 surgical specimens, were used in histoculture drug response assays to determine the chemosensitivity of cervical cancer specimens to NDP. Each specimen was assessed for immunohistochemical expression of Ki-67, p53, B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), cleaved caspase-3, cyclooxygenase-2 (COX-2), and excision repair cross-complementation group 1 (ERCC1). The results revealed that low or negative expression of p53, Bcl-2 and COX-2, and high or positive expression of cleaved caspase-3 were significantly correlated with high sensitivity to NDP. However, there were no significant differences in Ki-67, Bax or ERCC1 expression between the low and high sensitivity groups. These findings indicate that sensitivity to platinum may be easily predicted by immunostaining for the detection of these specific factors in pretreatment biopsies or surgical specimens. The expression profiles of these targets may therefore provide additional information for planning individualized chemotherapy in the treatment of cervical cancer.

Inhibition of microRNA-196a might reverse cisplatin resistance of A549/DDP non-small-cell lung cancer cell line.

We aimed to explore the possible mechanism of microRNA-196a (miR-196a) inhibition and reversion of drug resistance to cisplatin (DDP) of the A549/DDP non-small-cell lung cancer (NSCLC) cell line. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect expression differences of miR-196a in the drug-resistant A549/DDP NLCLC cell line and the parental A549 cell line, and expressions of miR-196a in the A549/DDP NLCLC cell line transfected with miR-196a inhibitor (anti-miR-196a group) and the miR-196a negative control (miR-NC) group and blank group (without transfection). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test was applied in examining the cell viability of A549/DDP cell line before and after transfection. Clonogenic assay was used to detect cell proliferation ability. Flow cytometry was applied in detecting apoptosis rate of assayed tumor cell and rhodamine-123 changes in cells. Western blot was applied in detecting proteins of drug-resistant related gene in A549/DDP cell line. Significantly higher expression of miR-196a was detected in the drug-resistant A549/DDP cell line than that in the parental A549 cell line (P < 0.05). However, miR-196a expression in the anti-miR-196a group decreased obviously compared to that in the blank group and the miR-NC group (both P < 0.05); The value of IC50 in the anti-miR-196a group showed remarkably lower than that in the blank group and the miR-NC group (both P < 0.05); Rh-123 absorbing ability in the anti-miR-196a group increased 2.51 times and 2.49 times respectively compared to that in the blank group and the miR-NC group (both P < 0.05). No statistical differences in the apoptosis rate of A549/DDP cell line in the early stage were found among the three groups (all P > 0.05), but the late-stage apoptosis rate in the anti-miR-196a group was significantly higher than that in the blank group and the miR-NC group (both P < 0.05); The expressions of human multidrug resistance 1 (MDR1), multidrug resistance protein 1 (MRP1), excision repair cross-complementation 1 (ERCC1), survivin, and B cell lymphoma 2 (Bcl-2) decreased significantly while RhoE increased significantly in the anti-miR-196a group than the blank group and the miR-NC group (all P < 0.05). Inhibition of miR-196a could reverse cisplatin resistance of A549/DDP cell lines, which might relate with inhibition of drug efflux, down-regulation of drug-resistant protein expression, cell apoptosis, and cell proliferation suppression.

Relationship between excision repair cross-complementation group 1 methylation and sensitivity to cisplatin-based concurrent chemoradiotherapy in cervical squamous cell carcinoma

Objective To investigate the correlation of the excision repair cross-complementation group 1(ERCC1) gene methylation status with sensitivity to cisplatin-based concurrent chemoradiotherapy and clinical pathological characteristics in patients with cervical squamous cell carcinoma (CSCC). Methods Methylation specific polymerase chain reaction was used to determine the ERCC1 gene methylation status in cervical tissue from 20 healthy people and 60 patients with CSCC. All patients with CSCC were treated with cisplatin-based concurrent chemoradiotherapy. The treatment outcomes were evaluated using the Response Evaluation Criteria in Solid Tumors. Based on the treatment outcomes, patients with a complete response were assigned to chemoradiotherapy-sensitive group, and patients with a partial response, stable disease, or progressive disease were assigned to chemoradiotherapy-resistant group. Comparison of the ERCC1 gene methylation status between the two groups was made by χ2 test, and multivariate logistic regression analysis was used to analyze the relationship of the ERCC1 gene methylation status with various clinical pathological characteristics and sensitivity to chemoradiotherapy. Results The ERCC1 gene methylation rate was significantly higher in cervical tissue with CSCC than in normal cervical tissue (60% vs. 0%, P=0.000). The multivariate analysis showed that ERCC1 gene methylation was an independent influencing factor for sensitivity to cisplatin-based concurrent chemoradiotherapy in CSCC (P=0.022); ERCC1 gene methylation was significantly correlated with histological grade of CSCC (P=0.030); there was no significant relationship of ERCC1 gene methylation with clinical pathological characteristics including age, tumor size, lymph node metastasis, FIGO stage, and pretreatment hemoglobin and platelet count (P=0.729, 0.707, 0.340, 0.747, 0.073, 1.000). Conclusions The ERCC1 gene promoter methylation status may be involved in the development and progression of CSCC. It may also influence the sensitivity of patients with CSCC to cisplatin-based concurrent chemoradiotherapy by playing a role in cell differentiation. Key words: Excision repair cross-complementation group 1; Radiosensitivity; Cervical neoplasms/radiotherapy; Cervical neoplasms/chemotherapy

Fusion of Quantitative Image and Genomic Biomarkers to Improve Prognosis Assessment of Early Stage Lung Cancer Patients.

This study aims to develop a new quantitative image feature analysis scheme and investigate its role along with two genomic biomarkers, namely protein expression of the excision repair cross-complementing 1 genes and a regulatory subunit of ribonucleotide reductase (RRM1), in predicting cancer recurrence risk of stage I nonsmall-cell lung cancer (NSCLC) patients after surgery. By using chest computed tomography images, we developed a computer-aided detection scheme to segment lung tumors and computed tumor-related image features. After feature selection, we trained a Naïve Bayesian network-based classifier using eight image features and a multilayer perceptron classifier using two genomic biomarkers to predict cancer recurrence risk, respectively. Two classifiers were trained and tested using a dataset with 79 stage I NSCLC cases, a synthetic minority oversampling technique and a leave-one-case-out validation method. A fusion method was also applied to combine prediction scores of two classifiers. Areas under ROC curves (AUC) values are 0.78 ± 0.06 and 0.68 ± 0.07 when using the image feature and genomic biomarker-based classifiers, respectively. AUC value significantly increased to 0.84±0.05 ( ) when fusion of two classifier-generated prediction scores using an equal weighting factor. A quantitative image feature-based classifier yielded significantly higher discriminatory power than a genomic biomarker-based classifier in predicting cancer recurrence risk. Fusion of prediction scores generated by the two classifiers further improved prediction performance. We demonstrated a new approach that has potential to assist clinicians in more effectively managing stage I NSCLC patients to reduce cancer recurrence risk.

Genetic Variants That Predispose to DNA Double-Strand Breaks in Lymphocytes From a Subset of Patients With Familial Colorectal Carcinomas

DNA structural lesions are prevalent in sporadic colorectal cancer. Therefore, we proposed that gene variants that predispose to DNA double-strand breaks (DSBs) would be found in patients with familial colorectal carcinomas of an undefined genetic basis (UFCRC). We collected primary T cells from 25 patients with UFCRC and matched patients without colorectal cancer (controls) and assayed for DSBs. We performed exome sequence analyses of germline DNA from 20 patients with UFCRC and 5 undiagnosed patients with polyposis. The prevalence of identified variants in genes linked to DNA integrity was compared with that of individuals without a family history of cancer. The effects of representative variants found to be associated with UFCRC was confirmed in functional assays with HCT116 cells. Primary T cells from most patients with UFCRC had increased levels of the DSB marker γ(phosphorylated)histone2AX (γH2AX) after treatment with DNA damaging agents, compared with T cells from controls (P < .001). Exome sequence analysis identified a mean 1.4 rare variants per patient that were predicted to disrupt functions of genes relevant to DSBs. Controls (from public databases) had a much lower frequency of variants in the same genes (P < .001). Knockdown of representative variant genes in HCT116 CRC cells increased γH2AX. A detailed analysis of immortalized patient-derived B cells that contained variants in the Werner syndrome, RecQ helicase-like gene (WRN, encoding T705I), and excision repair cross-complementation group 6 (ERCC6, encoding N180Y) showed reduced levels of these proteins and increased DSBs, compared with B cells from controls. This phenotype was rescued by exogenous expression of WRN or ERCC6. Direct analysis of the recombinant variant proteins confirmed defective enzymatic activities. These results provide evidence that defects in suppression of DSBs underlie some cases of UFCRC; these can be identified by assays of circulating lymphocytes. We specifically associated UFCRC with variants in WRN and ERCC6 that reduce the capacity for repair of DNA DSBs. These observations could lead to a simple screening strategy for UFCRC, and provide insight into the pathogenic mechanisms of colorectal carcinogenesis.

Protective Effect of Diphlorethohydroxycarmalol against Ultraviolet B Radiation-Induced DNA Damage by Inducing the Nucleotide Excision Repair System in HaCaT Human Keratinocytes.

We investigated the protective properties of diphlorethohydroxycarmalol (DPHC), a phlorotannin, against ultraviolet B (UVB) radiation-induced cyclobutane pyrimidine dimers (CPDs) in HaCaT human keratinocytes. The nucleotide excision repair (NER) system is the pathway by which cells identify and repair bulky, helix-distorting DNA lesions such as ultraviolet (UV) radiation-induced CPDs and 6-4 photoproducts. CPDs levels were elevated in UVB-exposed cells; however, this increase was reduced by DPHC. Expression levels of xeroderma pigmentosum complementation group C (XPC) and excision repair cross-complementing 1 (ERCC1), which are essential components of the NER pathway, were induced in DPHC-treated cells. Expression of XPC and ERCC1 were reduced following UVB exposure, whereas DPHC treatment partially restored the levels of both proteins. DPHC also increased expression of transcription factor specificity protein 1 (SP1) and sirtuin 1, an up-regulator of XPC, in UVB-exposed cells. DPHC restored binding of the SP1 to the XPC promoter, which is reduced in UVB-exposed cells. These results indicate that DPHC can protect cells against UVB-induced DNA damage by inducing the NER system.

Predictive Value of Ercc1 and Xpd Polymorphisms for Clinical Outcomes of Patients Receiving Neoadjuvant Therapy: A Prisma-Compliant Meta-Analysis.

Excision repair cross complementing 1 (ERCC1) and xeroderma pigmentosum group D (XPD) play important roles in the nucleotide excision repair (NER) pathway. The correlation between ERCC1 polymorphisms (rs11615 and rs3212986) and XPD polymorphisms (rs13181 and rs1799793) with the response rate and overall survival of cancer patients who accept neoadjuvant therapy has been extensively investigated. However, the results are inconclusive. In this study, we performed a meta-analysis to determine the strength of this correlation. A comprehensive literature search was conducted in Medline, PubMed, and Embase up to February 2015. A review of all titles and abstracts was performed by 2 of the authors to screen the articles based on the eligibility criteria. Clinical trials, observational studies, and epidemiological studies describing ERCC polymorphisms and neoadjuvant treatment were considered for review. The response rate was analyzed using pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs). Overall survival was assessed using the hazard ratio (HR) with corresponding 95% confidence intervals. In the present meta-analysis, we demonstrated that the ERCC1 rs3212986 polymorphism was significantly correlated with the response rate of esophageal cancer patients to neoadjuvant therapy (OR = .49, 95% CI = 0.31-0.76, heterogeneity P = 0.480). Furthermore, a considerable correlation was observed between ERCC1 rs11615 and the response rate of esophageal cancer patients to neoadjuvant therapy (OR = 0.228, 95% CI = 0.125-0.418, heterogeneity P = 0.291). No correlation was observed in the meta-analysis of overall survival. The individual studies included in our study differed in their patient selection and therapeutic protocols, which might lead to some bias in the results. These findings indicate that the ERCC1 rs11615 and ERCC1 rs312986 polymorphisms may be candidate pharmacogenomic factors capable of predicting the response rate of esophageal cancer patients who accept neoadjuvant therapy. Further studies are warranted.

Abstract 4429: EGR1-MIR152 pathway overcomes acquired cisplatin resistance in ovarian cancer cells by inhibiting cyto-protective autophagy via ATG14

Abstract The cytotoxic-based platinum compound cisplatin has been commonly used in ovarian cancer treatment for almost three decades. However, the intrinsic and acquired resistance to cisplatin in cancer cells remains a big challenge for overall survival. A growing body of evidence indicates a role of autophagy as a prosurvival and resistance mechanism against chemotherapy. Here, we reported MIR152 as a new autophagy-regulating miRNA that plays a role in cisplatin resistance. We showed that MIR152 expression was dramatically downregulated in the cisplatin-resistant cell lines A2780/CP70, SKOV3/DDP compared with their respective parental cells, and in ovarian cancer tissues associated with cisplatin resistance. Overexpression of MIR152 sensitized cisplatin-resistant ovarian cancer cells by reducing cisplatin-induced autophagy, enhancing cisplatin-induced apoptosis and inhibition of cell proliferation. A mouse subcutaneous xenograft tumor model using A2780/CP70 cells with overexpressing MIR152 was established and displayed decreased tumor growth in response to cisplatin. We also identified that ATG14 is a functional target of MIR152 in regulating autophagy inhibition. Furthermore, we found that EGR1 (early growth response 1) regulated the MIR152 gene at the transcriptional level. Ectopic expression of EGR1 enhanced efficacy of chemotherapy in A2780/CP70 cells. More importantly, these findings were relevant to clinical cases. Both EGR1 and MIR152 expression levels were significantly lower in human ovarian cancer tissues with high levels of ERCC1 (excision repair cross-complementation group 1), a marker for cisplatin resistance. Collectively, these data provide insights into novel mechanisms for acquired cisplatin resistance. Activation of EGR1 and MIR152 may be a useful therapeutic strategy to overcome cisplatin resistance by preventing cyto-protective autophagy in ovarian cancer. Note: This abstract was not presented at the meeting. Citation Format: Jun He, Jing-Jie Yu, Bing-Hua Jiang. EGR1-MIR152 pathway overcomes acquired cisplatin resistance in ovarian cancer cells by inhibiting cyto-protective autophagy via ATG14. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4429. doi:10.1158/1538-7445.AM2015-4429

The Cerebro-oculo-facio-skeletal Syndrome Point Mutation F231L in the ERCC1 DNA Repair Protein Causes Dissociation of the ERCC1-XPF Complex

The ERCC1-XPF heterodimer, a structure-specific DNA endonuclease, is best known for its function in the nucleotide excision repair (NER) pathway. The ERCC1 point mutation F231L, located at the hydrophobic interaction interface of ERCC1 (excision repair cross-complementation group 1) and XPF (xeroderma pigmentosum complementation group F), leads to severe NER pathway deficiencies. Here, we analyze biophysical properties and report the NMR structure of the complex of the C-terminal tandem helix-hairpin-helix domains of ERCC1-XPF that contains this mutation. The structures of wild type and the F231L mutant are very similar. The F231L mutation results in only a small disturbance of the ERCC1-XPF interface, where, in contrast to Phe(231), Leu(231) lacks interactions stabilizing the ERCC1-XPF complex. One of the two anchor points is severely distorted, and this results in a more dynamic complex, causing reduced stability and an increased dissociation rate of the mutant complex as compared with wild type. These data provide a biophysical explanation for the severe NER deficiencies caused by this mutation.

Prognostic Value of Excision Repair Cross-Complementing Gene 1, Dihydropyrimidine Dehydrogenase, and Human Equilibrative Nucleotide Transporter 1 Expression and Their Implications for Adjuvant Treatment in Patients With Ampullary Carcinoma.

The purpose of this study was to characterize the intratumoral expression profiles of excision repair cross-complementing gene 1 (ERCC1), dihydropyrimidine dehydrogenase (DPD), and human equilibrative nucleotide transporter 1 (hENT1) in ampullary carcinomas (ACs) to evaluate their prognostic values and better tailor adjuvant chemotherapy for individual patients with AC after surgery. This study included 49 patients with AC who underwent a curative pancreaticoduodenectomy. Various clinicopathological factors, including ERCC1, DPD, and hENT1, were analyzed in relation to postoperative disease recurrence and the patients' survival. The median recurrence-free survival and overall survival were 24.5 months and 32.4 months, respectively. Multivariate Cox regression analysis of recurrence-free survival identified a DPD expression (hazard ratio [HR], 8.18; 95% confidence interval [CI], 2.00-34.8; P = 0.003) and combined ERCC1/DPD expression (HR, 134.8; 95% CI, 11.8-1920; P < 0.001) as independent predictors of disease recurrence. Multivariate Cox regression analysis of overall survival also identified a DPD expression (HR, 8.48; 95% CI, 1.71-46.3; P = 0.008) and combined ERCC1/ DPD expression (HR, 135.6; 95% CI, 11.8-1940; P < 0.001) as independent predictors of survival. The DPD and ERCC1 expression profile could potentially serve as a useful prognostic biomarker and therapeutic target for surgically resected patients with AC.

Abstract LB-044: Germline mutations in patients with hereditary breast and ovarian cancer establish ERCC2 as a cancer susceptibility gene

Abstract Introduction: Breast and ovarian cancer (BC/OC) predisposition is associated with a number of high- and low-penetrance susceptibility genes. Despite comprehensive testing there is still a large portion of high risk cases without mutation in any of the known susceptibility loci. Therefore novel candidate genes need to be identified. Here we report on the results of testing 94 genes in 717 BC/OC patients from Germany and Lithuania. Method: Inclusion criteria for the patients in this study were defined by the German Consortium for Breast and Ovarian Cancer. Next generation sequencing (NGS) was performed on an Illumina MiSeq sequencer, with 150 bp paired end sequencing chemistry and an average base coverage of 300 fold. Target enrichment was performed with the Illumina TruSight cancer panel, which includes 94 genes associated with both common (e.g., breast, colorectal) and rare cancers. Results: In 19.7% of the patients, BRCA1 or BRCA2 variations have been found. These were either clearly pathogenic loss-of-function mutations (43%) or very rare, unclassified missense variations with high probability of a deleterious effect (57%). In 17.9% of the patients we found null-mutations and rare, unclassified missense variants in the acknowledged BC/OC susceptibility genes ATM, CDH1, CHEK2, NBN, PALB2, RAD51C/D and TP53. Analysis of the non-BC/OC genes on the NGS panel identified the “excision repair cross-complementing rodent repair deficiency, complementation group 2” gene (ERCC2 or XPD) as a promising BC/OC predisposition candidate: we found 3 frame-shift mutations and 1 splice-site mutation in four independent BC/OC families. Additionally we found 20 rare, unclassified sequence variations in ERCC2. These variants have a cumulative allele frequency of 2.9% in our BC/OC cohort, which is 14.5-fold overrepresentation compared to the “exome aggregation consortium” (ExAC) cohort (61486 exomes). In all affected families tested so far, the ERCC2 mutations co-segregate with the occurrence of BC and/or OC. Functional assays testing the ERCC2 variants have been initiated. First results show that at least some of the missense variants (e.g. NM_000400.3:p.Val536Met) have lost their DNA repair ability. Conclusion: Deleterious mutations and probably pathogenic missense variations in ERCC2, which are significantly overrepresented in our BC/OC families and co-segregate with the affected individuals, define ERCC2 clearly as a susceptibility gene for BC/OC predisposition. Functional assays will be continued in order to identify missense variations that diminish the DNA-repair capacity of ERCC2. Affected individuals with excluded mutations in the known BC/OC predisposition genes should be tested for mutations in ERCC2. Citation Format: Evelin Schrock, Anna Benet-Pagès, Steffen Schubert, Ramūnas Janavicius, Karl Hackmann, Elitza Betcheva-Krajcir, Luisa Mackenroth, Janin Lehmann, AM Nissen, Janine Altmueller, Holger Thiele, Nataliya Di Donato, Barbara Klink, Jan D. Kuhlmann, Andreas Tzschach, Karin Kast, Pauline Wimberger, Elke Holinski-Feder, Alfons Meindl, Steffen Emmert, Andreas Rump. Germline mutations in patients with hereditary breast and ovarian cancer establish ERCC2 as a cancer susceptibility gene. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-044. doi:10.1158/1538-7445.AM2015-LB-044

The prognostic and predictive value of excision repair cross-complementation group 1 (ERCC1) protein in 1288 patients with head and neck squamous cell carcinoma treated with platinum-based therapy: a meta-analysis.

Excision repair cross-complementation group 1 (ERCC1) protein has been extensively investigated as a prognostic and predictive factor for platinum-based treatment in head and neck squamous cell carcinoma (HNSCC) but with inconsistent results. We performed the present meta-analysis to better elucidate this issue in advanced HNSCC. A literature search was conducted using the PubMed and Web of Science databases. The inclusion criteria were head and neck cancer patients with platinum-based treatment and evaluation of the correlation between ERCC1 expression and clinical outcomes [objective response rate (ORR), progression-free survival (PFS), and overall survival (OS), both unadjusted and adjusted estimates]. In high vs. low pooled analyses, high ERCC1 expression was associated with unfavorable OS [hazard ratio (HR)=1.95, 95% confidence interval (CI) 1.18-3.21, p=0.009], PFS (HR=2.39, 95% CI 1.74-3.28, p=0.000) and ORR (odds ratio=0.48, 95% CI 0.23-0.98, p=0.044). In the subgroup analysis of adjusted OS estimates, ERCC1 was a predictor of shorter survival in Asians (HR=3.13, 95% CI 2.09-4.70, p=0.000) and Caucasians (HR=2.02, 95% CI 1.32-3.07, p=0.001) but of longer survival in South Americans (HR=0.17, 95% CI 0.07-0.40, p=0.000). Immunohistochemistry proved to be of predictive value irrespective of used antibody (p=0.009). In the stratified analysis according to the tumor site, ERCC1 expression was associated with OS in nasopharyngeal cancer (HR=2.72, 95% CI 1.79-4.13, p=0.000). ERCC1 has a potential to become predictive and prognostic factor enabling treatment tailoring in HNSCC patients.

Prognostic significance of the mRNA expression of ERCC1, RRM1, TUBB3 and TYMS genes in patients with non-small cell lung cancer.

The present study aimed to investigate the prognostic value of excision repair cross-complementing 1 (ERCC1), ribonucleotide reductase subunit M1 (RRM1), class III β-tubulin (TUBB3) and thymidylate synthase (TYMS) in patients with non-small cell lung cancer (NSCLC) receiving platinum-based adjuvant chemotherapy. The mRNA expression of these genes was assessed in 72 tumor tissue samples obtained following surgery, using multiplex branched-DNA technology. Subsequent to surgery, all 72 patients with NSCLC were treated with platinum-based chemotherapy. The expression of these five genes was analyzed and the correlation with clinical characteristics and patient survival was investigated. Among the 72 samples, the incidence rate of mRNA expression of ERCC1 was 38.9% (28/72), RRM1 was 55.6% (40/72), TUBB3 was 47.2% (34/72) and TYMS was 62.5% (45/72). The incidence rate of ERCC1 expression in adenocarcinoma (34.2%) was significantly lower than that in non-adenocarcinoma (44.1%; P<0.05). Furthermore, the incidence rates of TYMS and TUBB3 expression in the high-median differentiation tissue samples were significantly lower than those in the low differentiation tissue samples (P<0.05). When the correlation of gene expression and patient survival was analyzed, high expression of ERCC1, RRM1, TUBB3 or TYMS was found to be associated with poor prognosis (P<0.001, P=0.001, P=0.001 and P=0.001, respectively). ERCC1, RRM1, TUBB3 and TYMS are key factors involved in survival following surgical treatment in patients with NSCLC. The mRNA expression of these genes may have prognostic value for patients with NSCLC treated with platinum-based chemotherapy.

Expression of tumor heterogeneity-related genes in esophageal squamous cell carcinoma and its predictive value for chemotherapy sensitivity

Objective To investigate the expression of excision repair cross-complementation group 1 (ERCC1) and ribonucleotide reductase subunit M1 (RRM1) in patients with esophageal squamous cell carcinoma, and the relationship between the expression of ERCC1 and RRM1 genes and chemotherapy sensitivity. Methods A total of 77 patients with esophageal squamous cell carcinoma admitted in hospital from Jan. 2008 to Dec. 2012 were recruited. ERCC1 and RRM1 mRNA levels in the cancerous tissue were detected by real-time fluorescent quantitative RT-PCR. The relationship between short-term effects of chemotherapy and ERCC1 and RRM1 mRNA levels was analyzed. Results Levels of mRNA in stages Ⅰa, Ⅰb, Ⅱa, and Ⅱb were (0.578±0.081), (0.560±0.084), (0.521±0.080), (0.464±0.091) for ERCC1 and( 0.511±0.089), (0.539±0.086), (0.584±0.092), (0.637±0.101 )for RRM1, respectively. As the clinical stage advanced, the ERCC1 mRNA level declined and the RRM1 mRNA level increased (t=2.679 and 2.952, P=0.034 and 0.025, respectively). Levels of mRNA in patients with complete remission, partial remission, stable disease and progressive disease were (0.487±0.097, 0.511±0.095, 0.552±0.086, 0.568±0.088)for ERCC1 and(0.504±0.091, 0.544±0.095, 0.595±0.093, 0.616±0.097)for RRM1, respectively. The clinical effect of chemotherapy was negatively correlated with mRNA expression of ERCC1 and RRM1 (r=0.567, P=0.032). Conclusions Levels of ERCC1 and RRM1 mRNA expression are correlated with the staging of esophageal squamous cell carcinoma and chemotherapy sensitivity, and can be used as a predictive parameter for chemotherapy sensitivity in patients with esophageal squamous cell carcinoma. Key words: DNA-Repair; Esophageal neoplasms; Antineo plastic combined chemotherapy Protocols; Genes, tumor suppressor

Predictive Role of ERCC1 Expression in Head and Neck Squamous Cell Carcinoma Patients Treated with Surgery and Adjuvant Cisplatin-Based Chemoradiation

Objective: ERCC1 (excision repair cross-complementation group 1) expression predicts survival in patients with locally advanced head and neck squamous cell carcinoma (HNSCC) treated with chemoradiation. In order to evaluate the predictive role in the adjuvant setting, we investigated ERCC1 expression in radically resected HNSCC patients who underwent surgery and cisplatin chemoradiation. Methods: ERCC1 expression levels were determined by immunohistochemistry in primary tumor tissues from 48 patients with stage III-IV cancers. The median follow-up was 38.5 months (range: 5-121). Results: High ERCC1 expression was observed in 36 (75%) patients. Univariate analysis showed that patients with high levels of ERCC1 had significantly worse disease-free survival and overall survival (OS) than patients with low levels (HR = 7.15; 95% CI, 1.68-30.35; p = 0.008 and HR = 9.90; 95% CI, 1.33-73.96; p = 0.025, respectively). In the multivariate analysis, high ERCC1 expression (HR = 7.36; 95% CI, 1.72-31.4; p = 0.007) together with high-risk category (HR = 2.69; 95% CI, 1.01-7.18; p = 0.048) were the best predictors for relapse. High ERCC1 expression was the only unfavorable independent determinant for OS (HR = 9.53; 95% CI, 1.27-71.35; p = 0.028). Conclusions: This investigation suggests that ERCC1 expression might be useful to predict prognosis in radically resected HNSCC patients treated with surgery and chemoradiation.

Tumor-related gene expression levels in pulmonary pleomorphic carcinoma.

BackgroundPulmonary pleomorphic carcinoma (PPC) is a rare type of non-small-cell lung cancer that belongs to the family of sarcomatoid carcinomas and is associated with poor prognosis. We investigated the expressions of tumor-related genes in resected PPC specimens.MethodsSpecimens resected from patients with PPC from July 2006 through April 2012 were investigated. Tumor segments were collected from the specimens by micro-dissection to extract mRNA, then RT-PCR was performed according to Dannenberg’s tumor profile method for semi-quantitation of tumor-related gene mRNA. To compare with other types of lung cancer, data from stage-matched adenocarcinoma (AC) and squamous cell carcinoma (SCC) cases in our database were also examined.ResultsThe gene expression levels of thymidylate synthase were significantly higher in PPC and SCC as compared to the AC specimens (p < 0.001). The levels of dihydropyrimidine dehydrogenase and thymidine phosphorylase mRNA in PPC showed a similar tendency to those in SCC, in contrast to AC. Furthermore, the expression level of excision repair cross-complementation group 1 mRNA in PPC specimens was similar to that reported in NSCLC, while the level of vascular endothelial growth factor (VEGF) expression was higher as compared to that reported for colorectal cancer.ConclusionsAlthough gene expression of tumor cannot be directly correlated to its sensitivity for anti-cancer drugs, it is likely that PPC tumors are not sensitive to anti-metabolic drugs. Anti-VEGF therapy may be a candidate for PPC, while cisplatin also remains a viable option.

Excision repair cross-complementation group 1 (ERCC1) protein expression and clinical outcome in resectable cholangiocarcinoma.

e15128 Background: Excision repair cross-complementation group 1 gene (ERCC1) encodes an enzyme, which is essential for the effective repair of DNA damage induced by alkylating agents. Mitomycin-ba...

Lentivirus-Mediated RNAi silencing targeting ERCC1 reverses cisplatin resistance in cisplatin-resistant ovarian carcinoma cell line.

The aim of the study was to investigate the potential mechanisms that interferencing of excision repair cross-complementing gene 1 (ERCC1) mediated by lentiviral vector in cisplatin-resistant ovarian cancer SKOV3/DDP cells. The human platinum-resistant ovarian carcinoma cell line SKOV3/DDP was transfected by pLVX-shRNA lentivirus. Interference efficiency for ERCC1 by lentiviruses transfection was detected by real-time polymerase chain reaction and western blot assay. CCK-8 assay was used for cell proliferation on cell resistance after transfection with ERCC1. Effects of cell apoptosis and cell cycles were detected by flow cytometry. The expression levels of ERCC1 were significantly suppressed in SKOV3/DDP cells after stably transfecting with shERCC1-recombinant plasmid. The results of cell viability assay demonstrated that interference with ERCC1 gene increased the sensitivity of SKOV3/DDP cells to cisplatin (p<0.01). ERCC1 gene-specific silencing promoted cell apoptosis of SKOV3/DDP cells (p<0.01) detected by flow cytometry. Cell cycle analysis results showed that the proportion of cells in G1 and S phase decreased, while the proportion of G2 phase cells increased in ERCC1-silencing cells. The differences were statistically significant (p<0.01), which demonstrated that stable interferencing with ERCC1 induced the cells arrest in G2 phase after being treated by DDP and silencing the expression of ERCC1 inhibited cell proliferation by preventing the progression of cell mitosis. ERCC1 gene silencing effectively reversed SKOV3/DDP cell resistance to cisplatin and increased sensitivity to cisplatin resistance in cisplatin-resistant ovarian cancer cells. Interference of ERCC1 promoted the apoptosis of SKOV3/DDP cells and prevented cell mitosis by inducing G0/G1 phase arrest. Thus, ERCC1 could be a potential therapeutic target for the therapy of cisplatin-resistant ovarian cancer and it would provide new ideas for epigenetic therapy of drug-resistant epithelial ovarian cancer.