Excision Repair Cross-complementing 1 Expression Research Articles

ERCC1 is a potential biomarker for predicting prognosis, immunotherapy, chemotherapy efficacy, and expression validation in HER2 over-expressing breast cancer

To investigate the relationship between Excision repair cross-complementation 1 (ERCC1) expression, clinicopathological features, and breast cancer prognosis in patients treated with trastuzumab. Further, we aim to explore the immune status of ERCC1 in breast cancer. The data were retrieved from publicly available databases like the Cancer Genome Atlas, Therapeutically Applicable Research to Generate Effective Treatments, and the Genotype-Tissue Expression. The data was used to perform differential expression analyses between tumor and normal tissues in pan-cancers, immune-related analysis, homologous recombination deficiency (HRD), tumor mutation burden, and microsatellite instability. A total of 210 patients with HER2 over-expressing breast cancer from the Fourth Hospital of Hebei Medical University between January 2013 to December 2015 were enrolled in the study. Ten adjacent normal tissues were used to study the expression pattern of ERCC1 in normal tissues.Immunohistochemistry was performed to study ERCC1 expression and immune cell infiltration in different status of ERCC1 expression. Further, the correlation between ERCC1 expression, immune cell infiltration clinicopathological features, and the prognosis of patients with breast cancer was analyzed. The immune analysis revealed a significant correlation between CD8+ T cell, CD4+ T cell, T helper cell, macrophages, mast cells, and ERCC1 expression. Spearman analysis show that ERCC1 expression is related to macrophages and T cells. A close correlation was observed between increased ERCC1 expression and high tumor immune dysfunction and exclusion (TIDE) score as well as HRD. The results revealed a significant correlation among ERCC1, chemotherapy and estrogen receptor (ER; P < 0.05) expression. Univariate survival analysis revealed a significant correlation (P < 0.05) between that ERCC1 and ER expression, blood vessel invasion, and disease-free survival (DFS). ERCC1 and ER expression, tumor size, blood vessel invasion, pathological type, and lymph node metastases significantly correlated (P < 0.05) with overall survival in patients. Multivariate regression analysis revealed that ERCC1 expression and chemotherapy were independent factors that influence DFS. ERCC1 expression and vascular tumor thrombus were independent influencing factors that influence OS. A correlation was observed between high ERCC1 expression and poor patient prognosis. High ERCC1 expression also influences the efficacy of immunotherapy and chemotherapy.

Overexpression of excision repair cross-complementing 1 gene associates with higher risk of therapeutic failure after definitive chemoradiation for unresectable non-small cell lung cancer.

Locally advanced non-small cell lung cancer (NSCLC) is typically treated with concurrent chemoradiation (CRT). Excision Repair Cross-Complementing 1 (ERCC1) is a protein involved in DNA damage repair. The objective of this study was to assess whether higher tumoral ERCC1 expression would associate with worse clinical outcomes in NSCLC treated with CRT. Twenty-five patients were included. Relative expression levels of messenger RNA (mRNA) for ERCC1 were measured with a quantitative reverse transcription polymerase chain reaction (qRT-PCR) and expressed as scaled ERCC1 mRNA gene expression value. Patients were followed every 3 months with history, physical exam, and imaging to assess clinical outcomes. We evaluated the associations between ERCC1, as well as other prognostic variables including stage, age, gender, race, histology, RT dose, performance status, and progression free survival (PFS) and overall survival (OS) with Kaplan-Meier method and Cox regression. Recursive partitioning analysis identified a GeneExp cutoff of 1.54. Higher ERCC1 expression was associated with worse PFS [hazard ratio (HR) =1.70, P=0.04] and trended towards worse OS (HR =1.53, P=0.11). Increasing tumor volume (HR =1.001, P=0.055), squamous cell (HR =7.86, P=0.008) and poorly differentiated histology (HR =5.25, P=0.06) also associated with worse OS. The cumulative incidence of local recurrence at 1 year trended higher with ERCC1 GeneExp ≥1.54 (78.1%) compared to ERCC1 GeneExp <1.54 (14.9%, P=0.08). Distant relapse at 1 year was 72% with tumor ERCC1 expression ≥1.54 and 52% with ERCC1 expression <1.54 (P=0.28). Higher ERCC1 expression by qRT-PCR appears to correlate with worse PFS in locally advanced NSCLC treated with CRT. However, the overall sample size of the population was small; thus, larger studies are warranted to integrate molecular biomarkers to identify patients who might benefit from treatment intensification.

Predictive value of KRAS mutation and excision repair cross-complementing 1 (ERCC1) protein overexpression in patients with colorectal cancer administered FOLFOX regimen

BackgroundRecent studies have reported that KRAS mutational status is correlated with ERCC1 expression level. The purpose of this study was to determine the clinical significance of the KRAS mutation and ERCC1 overexpression status as predictive factors for resistance against oxaliplatin-based treatment. MethodsWe retrospectively analyzed clinicopathologic features, KRAS mutation status, and ERCC1 overexpression status in 386 patients with colorectal cancer (CRC) who underwent curative-intent surgery. Of these patients, 84 were administered the FOLFOX regimen as a first-line or adjuvant treatment. Disease-free survival and overall survival in groups separated by KRAS and ERCC1 statuses were analyzed. ResultsWild-type KRAS and ERCC1 overexpression were observed in 25.5% of all patients. Among the 84 patients who were treated with the FOLFOX regimen, 73 patients were evaluated for KRAS and ERCC1 status. There were no significant differences in disease-free survival or overall survival in groups separated by KRAS mutation and ERCC1 expression status. Subgroup analysis of patients with wild-type KRAS showed that overall survival in the ERCC1 overexpression group was lower than that of patients in the ERCC1 underexpression group (p = 0.029); however, no significant difference was found in the mutant KRAS patient group (p = 0.671). ConclusionsOur results suggest that CRC with wild-type KRAS and ERCC1 overexpression might be associated with oxaliplatin resistance. When considering oxaliplatin-based chemotherapy, the status of both KRAS mutation and ERCC1 overexpression should be evaluated.

Characteristics of Gastric Carcinomas With High ERCC1 Expression and the Prognostic Value of ERCC1 Expression.

We aimed to evaluate the characteristics of gastric carcinoma with high excision repair cross complementing 1 (ERCC1) expression and the prognostic value of ERCC1 expression. ERCC1 expression was evaluated by immunohistochemistry in 309 surgically resected gastric carcinoma specimens using a tissue microarray. Cancer-related survival was analysed using competing risk analysis. Compared to ERCC1-low gastric carcinomas, ERCC1-high gastric carcinomas showed less local invasion (p=0.0013), lower N stage (p=0.0302), earlier pTNM stage (p=0.0003), and less frequent recurrence (p=0002). Patients with ERCC1-high gastric carcinoma showed lower cumulative incidence function estimate of cancer-related death [3.37; 95% confidence intervaI (CI)=0.89-8.75] than did those with ERCC1-low gastric carcinoma (17.12; 95% CI=12.24-22.69; p-value by Gray's test=0.0012). Adjusted proportional sub-distribution hazard ratio for cancer-related death in the patients with ERCC1-high tumour was 0.272 (95% CI=0.084-0.878; p=0.0295). High ERCC1 expression may be an independent positive prognostic marker for gastric carcinoma.

Histone Deacetylase Inhibitor Sensitizes ERCC1-High Non-small-Cell Lung Cancer Cells to Cisplatin via Regulating miR-149

Resistance to platinum-based chemotherapy becomes a major obstacle in non-small-cell lung cancer (NSCLC) treatment. Overexpression of the excision repair cross-complementing 1 (ERCC1) gene is reported to negatively influence the effectiveness of cisplatin-based therapy for NSCLC cells. In this study, we confirm that high ERCC1 expression correlates with cisplatin resistance in NSCLC cells. Importantly, histone deacetylase inhibitors (HDACis) re-sensitize ERCC1-high NSCLC cells to cisplatin both in vitro and in vivo. Mechanistically, the HDACi induces the expression of miR-149 by acetylation and activation of E2F1, which directly targets ERCC1 and inhibits ERCC1 expression. Inhibition of miR-149 reverses the promotion effect of HDACis on cisplatin-induced DNA damage and cell apoptosis in ERCC1-high NSCLC cells. In conclusion, this study reveals a novel mechanism by which HDACis re-sensitizes ERCC1-high NSCLC cells to cisplatin via regulation of the E2F1/miR-149/ERCC1 axis, and we propose that combination of HDACis and cisplatin might hold promise to be a more effective therapeutic paradigm for ERCC1-high NSCLCs.

Chemoresistance in gastric cancer is attributed to the overexpression of excision repair cross-complementing 1 (ERCC1) caused by microRNA-122 dysregulation.

MicroRNAs are deemed as key regulators of gene expression. In particular, the elevated expression of excision repair cross-complementing 1 (ERCC1) significantly reduced the effectiveness of gastric cancer treatment by cisplatin (CDDP)-based therapies. In this paper, qRT-PCR and western blot were adopted to measure miR-122 and ERCC1 messenger RNA (mRNA) expression in all samples. Luciferase assay was carried out to verify the role of ERCC1 as a target of miR-122. The CCK-8 assay was carried out to study the effect of ERCC1 and miR-122 on cell survival and apoptosis. The results demonstrated that miR-122 expression was reduced in cisplatin-resistant gastric cancer. Using bioinformatic analysis, miR-122 was shown to target the 3'-UTR of human ERCC1. A dual-luciferase assay demonstrated that miR-122 downregulated ERCC1 expression, while the mutations in ERCC1 3'-UTR abolished its interaction with miR-122. Transfection of miR-122 mimics decreased the levels of ERCC1 mRNA and protein expression, while the transfection of miR-122 inhibitors increased the levels of both ERCC1 mRNA and protein expression. Furthermore, we found that overexpressed miR-122 promoted the proliferation of MKN74 cells and reduced their apoptotic by targeting ERCC1. In addition, the levels of miR-122 and ERCC1 were negatively correlated in gastric cancer samples. In summary, the reduced miR-122 expression may play an essential role in the induction of cisplatin-resistance by increasing ERCC1 expression.

Effect of 5-fluorouracil on excision repair cross-complementing 1 expression and consequent cytotoxicity regulation in human gastric cancer cells.

Gastric cancer is the third leading cause of cancer mortality all over the world. The combination therapy of surgery with chemotherapy, that is, 5-fluorouracil (5-FU) and platinum-containing anticancer drugs, is becoming a current clinical strategy for patients with gastric cancer because of the lower curative rate and higher cancer recurrence rate of patients treated with only surgery. However, the development of drug resistance in cancer cells is still the most challenge in clinical chemotherapy. Excision repair cross-complementing 1 (ERCC1), an essential member of nucleotide excision repair system, recently has been suggested to be a predictive biomarker of treatment evaluation and might affect the outcomes of chemotherapy. Thus, this study was aimed to investigate whether ERCC1 expression could be regulated, and its role in gastric cancer cells treated with 5-FU and the underlying mechanism. Human AGS gastric cancer cells were used in this study. It was shown that ERCC1 expression could be upregulated in AGS cells treated with 5-FU and this upregulation could subsequently attenuate the cytotoxicity of 5-FU in AGS cells. Moreover, 5-FU-upregulated ERCC1 expression was regulated by extracellular signal-regulated kinase (ERK) 1/2 and p38 signaling through activating the transcription factor c-jun/activator protein (AP)-1. These results indicated the role of ERCC1 in the development of drug resistance to 5-FU in AGS cells. The mechanism elucidation concerning the ERK1/2 and p38 kinases and transcription factor c-jun/AP-1 might contribute another idea to the development of chemotherapy strategy for the gastric cancers in the future.

Establishment and characterization of an oxaliplatin-resistant hepatic cancer cell line*

Abstract Objective The aim of the current study was to establish an oxaliplatin-resistant hepatoma cell line (HepG2/OXA) and investigate the potential mechanisms of its drug resistance. Methods The hepatoma cell subline, HepG2/OXA, resistant to oxaliplatin (OXA), was established from a parent cell line HepG2, by stepwise exposure to gradually increasing concentrations of OXA over a half-year period. Chemosenstivity of the cytotoxic drugs, OXA, cisplatin (CDDP), adriamycin (ADM), and 5-fuorouracil (5-FU), was determined in HepG2 and HepG2/OXA cells, by the Cell counting kit-8 (CCK8) assay. Cell cycle distribution of HepG2 and HepG2/OXA cells was analyzed by Flow cytometry (FCM). The expression levels of several drug resistance-related proteins, such as P-glycoprotein (P-gp), multidrug resistant protein 1 (MRP1), and excision repair-cross complementing 1 (ERCC1) protein in the two cell lines were tested by the western blot assay. Results The IC50 of OXA in HepG2/OXA and HepG2 were 136.84 µmol/L and 23.86 µmol/L, respectively. The resistance index (RI) was 5.34. HepG2 was also demonstrated to be cross-resistant to other anti-tumor agents, such as 5-FU, ADM, and CDDP. The percentage of HepG2/OXA cells in the S phase was significantly decreased compared to HepG2 cells (25.58% ± 2.36% vs 14.37% ± 2.54%, P &lt; 0.05), while the percentage of cells in the G0/G1 and G2/M phases showed no statistical difference (respectively 55.29% ± 4.98% vs 56.73% ± 4.56%, P &gt; 0.05, and 24.63% ± 4.81% vs 28.26% ± 3.82%, P &gt; 0.05). The ERCC1 was found to be over expressed in HepG2/OXA cells, while there was no difference in the expressions of P-gp and MRP1 between the multiple drug resistance (MDR) phenotype cell line and its parental cell line. Conclusion HepG2/OXA showed an MDR ability; the over expression of ERCC1 might be associated with the platinum resistance of the cells, but P-gp and MRP1 are not.

Predictive biomarkers for combined chemotherapy with 5-fluorouracil and cisplatin in oro- and hypopharyngeal cancers.

The present study aimed to identify significant correlations between gene expression and chemotherapy response to 5-fluorouracil (5-FU)/cisplatin in head and neck squamous cell carcinoma (HNSCC), and to identify patients who would benefit from induction chemotherapy for both organ preservation and survival. A total of 64 patients who underwent radical treatment for HNSCC were enrolled. All patients received induction chemotherapy with 5-FU/cisplatin and tumor responses were evaluated. Pretreatment biopsy specimens from all patients were assayed for mRNA expression of thymidylate synthase, dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyltransferase, tymidine phosphorylase, glutathione S-transferase-pi, p53, RB Transcriptional Corepressor 1, B-cell lymphoma 2 (Bcl-2), Bcl-xL, E2F Transcription Factor 1, epidermal growth factor receptor, human epidermal growth factor receptor 2, phosphoinositide 3-kinase, phosphatase and tensin homolog, vascular endothelial growth factor (VEGF), cyclooxygenase-2, XPA, DNA Damage Recognition And Repair Factor, excision repair cross-complementing 1 (ERCC1), multidrug resistance gene 1 (MDR1), multidrug resistance-associated protein 1, equilibrative nucleoside transporter 1 and β-tubulin by reverse transcription-quantitative polymerase chain reaction, and the association between the expression levels of these genes and patient response to chemotherapy was determined. The complete response (CR) group and non-CR group for induction chemotherapy comprised 32.8 and 67.2% of patients, respectively. The 5-year overall survival rate was significantly higher for the CR group (95%) compared with the non-CR group (57%). According to univariate analysis, chemotherapy response was associated with T-class and mRNA expressions of DPD, ERCC1, XPA, p53, Bcl-2, VEGF and MDR1. Multivariate analysis identified ERCC1 expression and T-class as significant predictors of response to chemotherapy, indicating that a DNA-repair pathway and apoptosis pathway are pivotal mechanisms governing response to chemotherapy. The findings suggest that ERCC1 expression could be a predictive biomarker for chemotherapy response to 5-FU/cisplatin in HNSCC. Assessing mRNA expression is a standard method for these studies, however further investigations examining polymorphisms and mutations in addition to apoptotic responses are required to determine target gene activation in HNSCC.

Expression of ERCC1, RRM1, TUBB3 in correlation with apoptosis repressor ARC, DNA mismatch repair proteins and p53 in liver metastasis of colorectal cancer.

Liver metastasis in colorectal cancer is common and the primary treatment is chemotherapy. To date, there is no routinely used test in clinical practice to predict the effectiveness of conventional chemotherapy. Therefore, biomarkers with predictive value for conventional chemotherapy would be of considerable benefit in treatment planning. We analysed three proteins [excision repair cross-complementing 1 (ERCC1), ribonucleoside-diphosphate reductase 1 (RRM1) and class III β-tubulin (TUBB3)] in colorectal cancer liver metastasis. We used tissue microarray slides with 101 liver metastasis samples, stained for ERCC1, RRM1 and TUBB3 and established scoring systems (fitted for tissue microarray) for each protein. In statistical analysis, we compared the expression of ERCC1, RRM1 and TUBB3 to mismatch proteins (MLH1, MSH2, MSH6 and PMS2), p53 and to apoptosis repressor protein (ARC). Statistically significant correlations were found between ERCC1, TUBB3 and MLH1, MSH2 and RRM1 and MSH2, MSH6. Noteworthy, our analysis revealed a strong significant correlation between cytoplasmic ARC expression and RRM1, TUBB3 (p=0.000 and p=0.001, respectively), implying an additional role of TUBB3 and RRM1 not only in therapy resistance, but also in the apoptotic machinery. Our data strengthens the importance of ERCC1, TUBB3 and RRM1 in the prediction of chemotherapy effectiveness and suggest new functional connections in DNA repair, microtubule network and apoptotic signaling (i.e. ARC protein). In conclusion, we showed the importance and need of predictive biomarkers in metastasized colorectal cancer and pointed out the relevance not only of single predictive markers but also of their interactions with other known and newly explored relations between different signaling pathways.

Effects of p38MAPK-mediated excision repair cross-complementation 1 expression on prognosis of patients with non-small cell lung cancer.

The present study aimed to investigate the effects of excision repair cross-complementation 1 (ERCC1) expression on the prognosis of patients with non-small cell lung cancer (NSCLC). A total of 140 patients with NSCLC who underwent radical resection were included. Immunohistochemical staining was performed on the tissue specimens obtained from patients and correlation analysis was used to determine the association between ERCC1 expression and clinicopathological characteristics. Cell proliferation was assessed using an MTT assay. The mRNA and protein expression levels were detected using reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. The expression of ERCC1 was demonstrated to be significantly elevated in tumor tissue compared with adjacent tissue samples. Furthermore, the expression of ERCC1 in squamous carcinoma was significantly higher compared with in adenocarcinoma samples. The expression of ERCC1 in patients who smoke was significantly higher compared with in the non-smokers. The 3-year disease-free survival (DFS) and overall survival (OS) for ERCC1-negative patients were higher compared with ERCC1-positive patients. Multivariate analysis demonstrated that ERCC1 expression, pathological staging, and tumor staging were important prognostic factors for NSCLC. Subgroup analysis revealed that the 3-year OS rate for ERCC1-negative patients with stage II–III tumors who received systematic adjuvant chemotherapy was higher compared with ERCC1-negative patients. The 3-year DFS and OS rates for ERCC1-negative patients with squamous carcinoma were higher compared with ERCC1-positive patients. In addition, p38 inhibitor treatment significantly inhibited the mRNA and protein expression levels of ERCC1 in A549 cells, and enhanced the sensitivity of cells to cisplatin. The results of the present study suggest that ERCC1 expression is an important prognostic indicator for NSCLC, particularly for patients with stage II–III tumors who receive systematic platinum-based adjuvant chemotherapy.

The Utility of Thyroid Transcription Factor 1 (TTF-1), Napsin A, Excision Repair Cross-Complementing 1 (ERCC1), Anaplastic Lymphoma Kinase (ALK) and the Epidermal Growth Factor Receptor (EGFR) Expression in Small Biopsy in Prognosis of Patients with Lung Adenocarcinoma - A Retrograde Single-Center Study from Croatia.

BackgroundThe present study was carried out in order to evaluate our institutional experience with small biopsy in diagnosis and molecular testing of lung adenocarcinoma. Few specific and predictive markers have been evaluated and correlated with clinicopathologic characteristics and survival in patients with lung adenocarcinoma who received platinum-based chemotherapy. There have not been such reports from Croatia.Material/MethodsA total of 142 cases of lung adenocarcinoma were retrospectively investigated in small biopsies for the immunohistochemical expression of TTF-1, napsin A, ERCC1, ALK, and the EGFR mutation by real-time polymerase chain reaction (rtPCR).ResultsTTF-1, napsin A, and ERCC1 expression was found in 81%, 78%, and 69% of patients, respectively, and the expressions were not significantly associated with subtype. Expression of ALK was found in 4% and EGFR mutation in 10% of patients. Exon 19 deletions were the most common. Longer survival was significantly associated with TTF-1 positivity (p=0.007) and napsin A positivity (p=0.026). Higher relative risk of death significantly correlated with positive expression of ERCC1 (p=0.041).ConclusionsPositive TTF-1 and napsin A expressions in lung adenocarcinoma tissues were useful diagnostic and favorable prognostic parameters. Positive ERCC1 expression was identified as a negative prognostic marker in patients treated with platinum-based chemotherapy. The percentages of EGFR and ALK mutations corresponded to those in previously published reports for Caucasians.

Higher Expression of ERCC1 May Be Associated with Resistance to Adjuvant Platinum-Based Chemotherapy in Gastric Cancer

ABSTRACTPotential predictive biomarker(s) to respond to chemotherapy in gastric cancer are unclear. Excision repair cross-complementing 1 (ERCC1), a DNA repair enzyme, is associated with clinical outcomes in gastric cancer. Here, we investigated the expression of ERCC1 in gastric cancer with platinum-based chemotherapy after surgery, and the association between ERCC1 expression and clinical parameters was analyzed. Our data showed that high levels of ERCC1 expression were positively associated with resistance to platinum-based chemotherapy but not with lymph node metastasis and pathological stage. In addition, patients with resistance to platinum-based chemotherapy probably had lymph node metastasis and pathological stage.

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.

255P Predictive value of ERCC1, ERCC2, ERCC4, and glutathione S-transferase P1 for FOLFIRINOX in unresectable pancreatic cancer

Background FOLFORINOX (leucovorin and fluorouracil plus irinotecan and oxaliplatin) is one of the current standard chemotherapy, along with gemcitabine plus nab-paclitaxel, for unresectable pancreatic cancer. However, it has a high level of toxicity including neutropenia and febrile neutropenia and has limitation in its indication. Presently, there are no predictive biomarkers for FOLFIRINOX. A correlation between increased excision repaircross-complementing1(ERCC1)expressionandnonresponsetoFOLFOXhasbeen reported for colon cancer. Therefore, in this study, we examined the expression of ERCC1, ERCC2,ERCC4,andGlutathioneS-TransferaseP1(GSTP1)aspredictivebiomarkers related to sensitivity to platinum agents. Methods The study population consisted of 34 patients (median age, 61 years) with unresectable pancreatic cancer who were treated with FOLFIRINOX. The expressions of ERCC1, ERCC2, ERCC4, and GSTP1 were examined using immunohistochemistry. The clinical outcome was investigated in terms of overall survival (OS), progression-free survival (PFS), response rate (RR), disease control rate (DCR), and the frequency of grade 3 or 4 neutropenia. Whether some background factors, such as ECOG performancestatus(PS)andneutrophil-to-ymphocyteratio(NLR)contributedto clinical outcome was evaluated by the Cox proportional hazards model. Results ERCC1, ERCC2, ERCC4, and GSTP1 were positive in 64%, 24%, 18%, and 64% of cases. There were no significant differences between outcomes and the expression patterns. The frequency of grade 3 or 4 neutropenia also did not correlate with the expression patterns. Multivariate analysis revealed that ECOG PS of 1 significantly impacted OS (HR: 9.50, 95% CI: 2.25-40.07, P = 0.002) and PFS (HR: 4.95, 95% CI: 75-14.00, P = 0.003) compared with PS of 0, and the NLR ^5 affected OS (HR: 6.02, 95%CI:1.20-30.29,P=0.03). Conclusions ERCC1, ERCC2, ERCC4, and GSTP1 were unlikely to be predictive biomarkersofFOLFIRINOXinthissetting. Legal entity responsible for the study Shun Tezuka Funding Kanagawa Cancer Center Disclosure All authors have declared no conflicts of interest.

Expression of excision repair cross-complementing 1, topoisomeraseII, ribonucleotide reductase M1, β3-tubulin and thymidylate synthase in lung cancer

Objective To analyze the expression characteristics of excision repair cross-complementing 1(ERCC1), topoisomerase Ⅱ (TOPO Ⅱ), ribonucleotide reductase M1(RRM1), β3-tubulin and thymidylate synthase (TS) in lung cancer and their associations with the pathological types. Methods The immunohistochemical EnVision method was used to determine the expression of ERCC1, TOPOⅡ, RRM1, β3-tubulin and TS in 548 patients who were diagnosed as lung cancer from January 2011 to December 2014. Variance analysis was performed to analyze their expression characteristics among different pathological types and correlation. Results The expression positive rates of ERCC1, TOPOⅡ, RRM1, β3-tubulin and TS were 61.86% (339/548), 91.06% (499/548), 62.59% (343/548), 73.18% (401/548) and 70.44% (386/548), respectively. The expression of ERCC1 was weak positive mostly (P<0.05), meanwhile the expression of TOPO Ⅱ was medium-strong positive mostly (P<0.05). In ERCC1 group, the positive rate of squamous cell carcinoma was higher than that of adenocarcinoma [57.39% (167/291) vs. 42.61% (124/291), P=0.000]. In weak positive of TOPOⅡ group, the proportion of adenocarcinoma was higher than that of squamous cell carcinoma[23.58% (100/137) vs. 8.73% (37/137), P=0.000]. In medium-strong positive of TOPO Ⅱ group, the proportion of squamous cell carcinoma was higher than that of adenocarcinoma[47.41% (201/287/) vs. 20.28% (86/287), P=0.000]. The expressions of ERCC1, TOPO Ⅱ, RRM1, β3-tubulin and TS were irrelevant (r=0.4, P=0.397). Conclusions The expressions of ERCC1 and TOPO Ⅱ are higher in squamous cell carcinoma than those in adenocarcinoma. The expression of ERCC1 is weak positive mostly, meanwhile the expression of TOPO Ⅱ is medium-strong positive mostly. There is no correlation between them. Key words: Lung neoplasms; Excision repair cross-complementing 1; Topoisomerase Ⅱ; Thymidylate synthase

Development and Validation of an ERCC1 Immunohistochemistry Assay for Solid Tumors

- Excision repair cross-complementation 1 (ERCC1) is a key enzyme in nuclear excision repair pathway and has a critical role in helping remove DNA adducts caused by cross-linking agents, such as platinum-containing cancer chemotherapies and other DNA-damaging therapeutic modalities. ERCC1 expression, evaluated by techniques such as immunohistochemistry, has been associated with clinical response; ERCC1+ tumors are more resistant to cisplatin treatment than are ERCC1- tumors. Although several immunohistochemistry, anti-ERCC1 antibodies are available, the 8F1 clone, in particular, has been used in many studies. Recent evidence has suggested that the 8F1 antibody cross-reacts with at least one other protein, raising concerns about the specificity of this clone. - To design an immunohistochemistry assay to detect ERCC1 levels that show dynamic range and consistent analytic performance. - Two different primary antibodies to ERCC1, clones 4F9 and D6G6, were evaluated on formalin-fixed, paraffin-embedded tissue. We then performed a fit-for-purpose assay validation with the 4F9 clone, which included sensitivity assessment across several solid tumor types and evaluation of analytic parameters, such as precision and reproducibility. - The 4F9 clone was consistently superior to the D6G6 clone in the optimization phase. A range of expression was seen in ovarian, head and neck, non-small cell lung, and esophageal cancer samples when tested with the 4F9 clone. The antibody showed acceptable reproducibility (31.02%) and precision (16.06%). - This assay can be used to assess ERCC1 levels during clinical studies of patient tumors from a variety of tumor types.

Expression of BRCA1, a factor closely associated with relapse-free survival, in patients who underwent neoadjuvant chemotherapy with docetaxel, cisplatin, and fluorouracil for squamous cell carcinoma of the esophagus.

The aim of this study was to identify the biomarkers associated with chemotherapeutic efficacy and long-term survival for patients with advanced squamous cell carcinoma of the esophagus (SCCE) who had received neoadjuvant chemotherapy with docetaxel and cisplatin plus 5-fluorouracil (NAC-DCF). This study included 45 patients with advanced SCCE who received NAC-DCF between 2008 and 2012. The NAC-DCF was conducted as a phase II study (UMIN000007408). The expressions of excision repair cross-complementing-1 (ERCC1), class III beta-tubulin, breast cancer susceptibility gene I (BRCA1), and thymidylate synthase were investigated simultaneously in the pre-treatment endoscopic tumor biopsy samples. A multivariate logistic regression analysis indicated that pathological responses were significantly associated with tumors with low ERCC1 expression (P=0.016) and with tumors with high BRCA1 expression (P=0.030). The multivariate Cox proportional hazard model analysis for relapse-free survival revealed high BRCA1 expression (P=0.031, hazards ratio 4.39) as the factor associated with survival. Low ERCC1 expression and high BRCA1 expression in patients with SCCE were associative biomarkers for chemotherapeutic efficacy. High BRCA1 expression was considered the factor associated with survival. These findings may be helpful for tailoring chemotherapy.

Expression of ERCC1, TUBB3, BRCA1, and TS as predictive markers of neoadjuvant chemotherapy for squamous cell carcinoma of the esophagus.

47 Background: No predictive biomarker of the response to neoadjuvant chemotherapy with docetaxel and cisplatin plus 5-fluorouracil (NAC-DCF) is available for patients with squamous cell carcinoma of the esophagus (SCCE) in a clinical setting. The aim of this study was to identify the biomarkers associated with chemotherapeutic efficacy and long-term survival for patients with advanced SCCE who had received NAC-DCF followed by surgery. Methods: This study included 45 patients with advanced SCCE who received NAC-DCF between January 2008 and December 2012. The NAC-DCF was conducted as a phase II study (UMIN000007408). The expressions of excision repair cross-complementing-1 (ERCC1), class III beta-tubulin, breast cancer susceptibility gene I (BRCA1), and thymidylate synthase were investigated simultaneously in the pre-treatment endoscopic tumor biopsy samples. Results: The multivariate logistic regression analysis indicated that pathological responses were significantly associated with tumors with low ERCC1 expression (P = 0.016) and with tumors with high BRCA1 expression (P = 0.014). The incidence of pathological responses to DCF in patients with low ERCC1 and high BRCA1 expressions was 100%. The multivariate Cox proportional hazard model analysis for relapse-free survival (RFS) revealed tumors with high BRCA1 expression (P = 0.031, hazards ratio, 4.39) as independent prognostic factors. Conclusions: Low ERCC1 expression and high BRCA1 expression in patients with SCCE were predictive biomarkers for chemotherapeutic efficacy. High BRCA1 expression was considered as prognostic factors for long-term RFS. These results may be a helpful tool for tailoring chemotherapy of patients with SCCE. Prospective validation of this biomarker panel is warranted. Clinical trial information: UMIN000007408.

Effect of SNX-2112 on proliferation of esophageal cancer cells via regulation of excision repair cross-complementing 1, epidermal growth factor receptor, and p53 expression.

SNX-2112 is a potential molecular targeted therapeutic drug against esophageal cancer (EC). However, its exact mechanism of action remains to be explained. The aim of this study was to investigate the effect of SNX-2112 on excision repair cross- complementing 1 (ERCC1), epidermal growth factor receptor (EGFR), and p53, to elucidate the mechanism of action of SNX-2112 on EC. Fresh tumor sections were surgically obtained from 65 patients with EC, and the expression of ERCC1, EGFR, and p53 was determined by immunohistochemical staining. Furthermore, the effect of SNX-2112 (0.2 μM) on the proliferation of EC-9706 cells and the expression of ERCC1, EGFR, and p53 in these cells were analyzed by a cell proliferation assay and western blot, respectively. We observed a significant decrease and increase in ERCC1 (P = 0.001) and p53 (P = 0.043) expression, respectively, and no significant difference in EGFR (P = 0.59) expression, with the TNM stage of EC, which suggested that ERCC1 and p53 could be potential markers for the TNM stage of EC. We also observed a significant increase in ERCC1 expression, and decrease in p53 and EGFR expression, in EC-9706 cells treated with SNX-2112 (P < 0.05), indicating the regulation of EC by SNX-2112. Furthermore, SNX-2112 treatment induced a significant decrease in the proliferation of EC-9706, which confirmed the function of SNX- 2112. In summary, SNX-2112 inhibits the proliferation of EC cells by regulating the expression of ERCC1, EGFR, and p53.