Excision Repair Cross-complementation Group 1 Expression Research Articles

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

Excision repair cross complementation group 1 (ERCC1) is a key component of homologous recombination-based repair of interstrand DNA cross-links (ICLs). As a consequence, ERCC1 mediates resistance to mitomycin C (MMC) and platinum chemotherapeutic agents and may predict treatment failure. Clinical response to MMC or cisplatin (CDDP)-based radiochemotherapy (RCT) was assessed in 106 head and neck squamous cell carcinoma (HNSCC) patients and correlated with cell nuclear immunoreactivity of the mouse monoclonal (clone: 8 F1) ERCC1 antibody in tumor tissue samples. BEAS-2B epithelial and Detroit 562 pharyngeal squamous carcinoma cells were treated with CDDP, MMC, and 5-fluorouracil (5-FU) at 50 % growth inhibitory (IC-50) concentrations. ERCC1 protein synthesis was compared with cell cycle distribution using combined immunocytochemistry and flow cytometry. ERCC1 messenger RNA (mRNA) and protein expression was investigated in normoxic and hypoxic conditions in Detroit 562 cells. Clinically, the nonresponder revealed significantly lower HNSCC tissue ERCC1 immunoreactivity than the responder (p = 0.0064) or control normal mucosa, which led to further mechanistic investigations. In vitro, control cells and cells treated with cytotoxic agents showed increasing ERCC1 levels from the G1 through S and G2 phases of the cell cycle. In CDDP-treated cells, ERCC1 mRNA and protein expression increased. Under hypoxic conditions, ERCC1 gene expression significantly decreased. Although ERCC1+ cells show increased chemoresistance, they might be particularly radiosensitive, representing G2 cell cycle phase and less hypoxic. ERCC1 expression might be indirectly related with some conditions important for RCT treatment, but it is not a clear predictor for its failure in HNSCC patients.Electronic supplementary materialThe online version of this article (doi:10.1007/s13277-014-2001-2) contains supplementary material, which is available to authorized users.

Commercial Laboratory Testing of Excision Repair Cross-Complementation Group 1 Expression in Non-Small Cell Lung Cancer

Excision repair cross-complementation group 1 (ERCC1) expression by non-small cell lung cancer (NSCLC) has been reported to predict resistance to platinum-based therapies. On this basis, several commercial laboratories have offered ERCC1 testing to facilitate clinical decision making, but the reliability of such assays has recently been called into question. Methods. First, three large commercial laboratories were queried for their cumulative ERCC1 test results in NSCLC patients to compare their independent rates of ERCC1 expression. Second, identical tumor blocks from individual NSCLC patients underwent round-robin analysis to evaluate interlaboratory concordance for ERCC1 expression. Third, a retrospective review of medical records from NSCLC patients identified those who were both highly responsive and resistant to platinum-based chemotherapies. Tumor blocks from these patients were then used in a gold standard analysis to determine individual laboratory sensitivity and specificity for ERCC1 results. Results. Significant differences were observed in independent laboratory ERRC1 expression rates (Clarient 70% vs. Genzyme 60% vs. Third Laboratory 44%, p < .0001 for all two-way comparisons). Only 4 of 18 tumors examined in round-robin analysis were fully concordant (κ ≤ 0.222 for all two-way comparisons). In preselected platinum responsive and resistant specimens, none of these three commercially marketed laboratory assays achieved a specificity of greater than 50%. Conclusion. The results of commercial laboratory testing for ERCC1 are inconsistent and unreliable. Better validation and postmarketing surveillance should be mandated before tumor biomarker assays are allowed to enter the clinical arena.

Expression of ribonucleoside reductase subunit M1, but not excision repair cross-complementation group 1, is predictive in muscle-invasive bladder cancer treated with chemotherapy and radiation.

The aim of this study was to determine the prognostic and predictive values of ribonucleoside reductase subunit M1 (RRM1) and excision repair cross-complementation group 1 (ERCC1) expression in patients with muscle-invasive bladder cancer treated with chemoradiotherapy. The expression of RRM1 and ERCC1 in pretreatment tumor samples of retrospectively identified patients was determined by immunohistochemical analysis. A total of 39 patients were included in this study; 49% were treated with neoadjuvant chemotherapy and 67% with concomitant chemoradiotherapy; 56% were treated with gemcitabine-based and 51% with platinum-based chemoradiotherapy. The median follow-up was 19 months (interquartile range, 11-50 months). Based on the immunohistochemical analysis, 44 and 32% of the tumors exhibited increased expression of RRM1 and ERCC1, respectively. The complete response (CR) and local recurrence rates following chemoradiotherapy were 79 and 21%, respectively. A low expression of RRM1 was associated with a higher rate of CR to chemoradiotherapy (95 vs. 57%, P=0.012); however, there was no such association with low ERCC1 expression (67 vs. 84%, P=0.39). RRM1 expression predicted an improved CR in patients treated with gemcitabine-based chemoradiotherapy (57 vs. 100%, P=0.036), but not in those treated with other agents (56 vs. 88%, P=0.29). ERCC1 expression was not found to be correlated with CR (67 vs. 84%, P=0.39), even when restricted to patients treated with platinum agents (71 vs. 75%, P=1.0). In the univariate analysis, RRM1 expression, but not ERCC1 expression, was identified as a prognostic marker for worse cancer-specific survival in all the patients and in those treated with gemcitabine-based regimens. No independent prognostic factor was identified in the multivariate model, which included tumor stage, vascular invasion, hydronephrosis and RRM1 status. Although these findings require further validation, they suggest that RRM1 may be a beneficial stratification variable for the selection of chemotherapy regimens for chemoradiotherapy, with patients with low RRM1 expression being considered suitable for gemcitabine treatment.

Changes in expression levels of excision repair cross-complementing group 1 (ERCC1) and dihydropyrimidine dehydrogenase (DPD) after first-line oxaliplatin-based chemotherapy for metastatic colorectal cancer: Results of a multicenter study.

463 Background: Our previous single-center study showed that expression levels of ERCC1 (a nucleotide excision repair pathway gene) and DPD (a pyrimidine catabolic pathway gene) in liver metastases from colorectal cancers (CRCs) were significantly higher in patients given oxaliplatin as first-line chemotherapy than those not given oxaliplatin. We conducted this multicenter study to validate our findings and better define a basic rationale for second-line therapy for metastatic CRC resistant to first-line therapy. Methods: Irinotecan-naive patients with mCRC (n = 190) were enrolled at 17 sites in Japan. Resected liver metastases were available for 91 patients who had received FOLFOX (or FOLFOX plus bevacizumab; FOLFOX group) and 99 who had not received oxaliplatin-based chemotherapy (non-oxaliplatin group). We measured mRNA expression levels of ERCC1 and DPD by real-time RT-PCR. Protein expression levels of ERCC1 and DPD were evaluated immunohistochemically. The methylation level of the long interspersed nucleotide element-1 (LINE-1; a surrogate m arker of global DNA methylation) was determined by pyrosequencing. Results: The median age at liver resection was 64 years (range, 32–89). Baseline features (e.g., sex, histology) were similar in the groups. Expression levels of DPD at the mRNA and protein levels were significantly higher in the FOLFOX group than in the non-oxaliplatin group (p &lt; 0.05). The mRNA expression level of ERCC1 was slightly, but not significantly higher in the FOLFOX group than in the non-oxaliplatin group (p = 0.053). Interestingly, ERCC1 expression levels correlated with DPD expression levels (r = 0.38, p&lt; 0.0001). LINE-1 methylation levels were similar in the groups. Conclusions: This multicenter study confirmed increased expression levels of DPD after first-line oxaliplatin-based chemotherapy, which may affect chemosensitivity to subsequent therapy. ERCC1 expression and epigenetic control by mechanisms such as aberrant promoter methylation of specific genes warrant further investigation.

Combination of TRAP1 and ERCC1 Expression Predicts Clinical Outcomes in Metastatic Colorectal Cancer Treated with Oxaliplatin/5-Fluorouracil

PurposeThe novel heat shock protein tumor necrosis factor receptor-associated protein 1 (TRAP1) is associated with multidrug resistance in colorectal cancer (CRC) cells in vitro. Excision repair cross-complementation group 1 (ERCC1) expression levels in tumor tissues also predict clinical outcomes in metastatic CRC patients receiving combination oxaliplatin and 5-fluorouracil treatment. We investigated whether TRAP1 and ERCC1 protein expression by immunohistochemistry predict clinical outcomes in CRC patients.Materials and MethodsThe study population consisted of 56 patients with metastatic CRC who received first-line oxaliplatin/5-fluorouracil therapy. Clinical response and overall survival (OS) by levels of the markers TRAP1 and ERCC1 were evaluated.ResultsThe rates of TRAP1 and ERCC1 expression were 21% and 52%, respectively. Patients negative for ERCC1 expression showed a tendency to respond to chemotherapy (p=0.066). Median OS was significantly longer in patients negative for TRAP1 than those positive for TRAP1 (p=0.023). Patients negative for ERCC1 expression also had a better OS than those positive for ERCC1 (p=0.021). The median OS was 30.9 months for patients negative for TRAP1 and ERCC1 compared to 13.2 months for those positive for TRAP1 and/or positive for ERCC1 expression (p=0.006). The combination of TRAP1 and ERCC1 expression was significantly associated with the response to chemotherapy (p=0.046) and independently predicted median OS in multivariate analysis (hazard ratio, 2.98; 95% confidence interval, 1.18 to 7.49).ConclusionThe present study demonstrates that the combination of TRAP1 and ERCC1 expression predicts the survival of metastatic CRC patients who were treated with oxaliplatin/5-fluorouracil.

ERCC1 expression levels predict the outcome of platinum-based chemotherapies in advanced bladder cancer

The objective of this study was to provide a precise evaluation of whether expression levels of excision repair cross-complementation group 1 (ERCC1) are associated with objective response, overall survival (OS), and median survival in patients with advanced bladder cancer treated with platinum-based chemotherapy. Systematic computerized searches of the electronic databases PubMed, EMBASE, Ovid, ASCO, and CNKI were performed and a meta-analysis was carried out to evaluate the correlation between ERCC1 expression levels and objective response rate, OS, or progression-free survival in patients with advanced bladder cancer receiving platinum-based chemotherapy. References within the articles identified were also searched manually. STATA package version 11.0 was used for the comprehensive quantitative analyses. A total of six studies involving 356 patients, of which ERCC1 expression was high/positive in 138 (38.8%) and low/negative in 218 (61.2%), were included in the meta-analysis. The median age of the patients was 63.7 years. The objective response rate favored patients with ERCC1 low/negative expression after platinum-based chemotherapy, but showed no significant difference [odds ratio 0.86, 95% confidence interval (CI) 0.36-2.06, P=0.734]. The median OS time and the median progression-free survival time were significantly prolonged when ERCC1 low/negative expression was compared with ERCC1 high/positive expression (hazard ratio 0.69, 95% CI 0.54-0.89, P=0.004, and hazard ratio 0.76, 95% CI 0.66-0.89, P=0.000, respectively). In conclusion, low/negative expression of ERCC1 was associated with higher objective response, median progression-free survival, and median OS in patients with advanced bladder cancer treated with platinum-based chemotherapy. ERCC1 may be a suitable marker of prognosis and sensitivity to platinum-based chemotherapy in patients with advanced bladder cancer. Larger studies and further clinical trials are warranted to confirm these findings.

ERCC1 mRNA expression is associated with the clinical outcome of non-small cell lung cancer treated with platinum-based chemotherapy.

We conducted a prospective study to analyze the expression of the excision repair cross-complementing group 1 (ERCC1) and ribonucleotide reductase subunit M1 (RRM1) genes in 297 Chinese patients with advanced non-small cell lung cancer (NSCLC). The goal of this study was to evaluate these genes as potential biomarkers for prediction of tumor response and clinical outcome. Patients with unresectable, locally advanced or metastatic NSCLC were enrolled between September 2007 and September 2009, and they were followed up until September 2012. A fluorescence-based real-time detection method was used to quantify relative levels of ERCC1 and RRM1 cDNA. Relative amounts of ERCC1 and RRM1 cDNA were calculated by comparing to actin. By the end of follow-up, 132 patients had died and 165 patients experienced progression. The median overall survival time was 18.7 months (range, 1-60 months). The median levels of ERCC1 and RRM1 were 2.46 x 10(-2) and 0.97 x 10(-2), respectively. Patients with low ERCC1 expression had a significantly higher rate of complete response to chemotherapy, with an OR (95%CI) of 1.56 (1.03-2.47). Moreover, individuals with low levels of ERCC1 had longer overall survival than patients with high expression, with an adjusted hazard ratio (95%CI) of 0.57 (0.35-0.93). In summary, low ERCC1 mRNA expression was associated with better response to chemotherapy and correlated with longer survival in advanced NSCLC patients treated with platinum-based chemotherapy.

Meta-analysis of Excision Repair Cross-complementation Group 1 (ERCC1) Association with Response to Platinum-based Chemotherapy in Ovarian Cancer

Recent studies suggested that the ovarian cancers with negative excision repair cross-complementation group 1 enzyme (ERCC1) expression have a better response to platinum-based chemotherapy than those with positive ERCC1 expression. The objective of this study was to evaluate whether ERCC1 expression is associated with response to platinum-based chemotherapy in ovarian cancers. MEDLINE, PubMed, Web of Science and CNKI databases were used for searching studies relating to ERCC1 protein expression and response to platinum-based chemotherapy in ovarian cancers. Statistical analysis was based on the method for a fixed effects meta-analysis. Pooled odds ratios (ORs) with 95% confidence intervals for ERCC1 protein expression and response to platinum- based chemotherapy were generated. Publication bias was investigated with Begg's test. Five studies involving 306 patients with ovarian cancer were included. Compared to patients with positive ERCC1 expression, those with negative ERCC1 expression had a better response to platinum-based chemotherapy. The pooled OR was 5.264 (95% CI: 2.928 - 9.464, P < 0.001) and publication bias was not found (P = 0.904). The result was similar in both in Asians and Caucasians (P < 0.001 and P = 0.028, respectively). ERCC1 protein expression status is significantly associated with response to platinum-based chemotherapy in ovarian cancers.

Change of ERCC1 expression of residual VX2 squamous carcinoma cells in rabbit lung after radiofrequency ablation

背景与目的残存肿瘤是影响射频消融（radiofrequency ablation, RFA）治疗肺恶性肿瘤效果的重要因素，联合铂类药物化疗是减少残存肿瘤的重要手段之一。核苷酸切除修复交叉互补基因1（excision repair cross-complementation group 1, ERCC1）的表达水平是影响铂类药物化疗效果的重要因素之一。RFA治疗后残存肿瘤会发生一些生物学特性变化，但有关ERCC1表达变化的研究尚无报道。本研究旨在探讨RFA治疗后兔肺内残存VX2鳞癌细胞ERCC1表达水平的变化。方法应用组织块悬液注射法建立兔VX2鳞癌肺内移植瘤模型。58只荷瘤新西兰白兔随机分为对照组（n=10）和RFA组（n=48）。在RFA治疗时，通过控制电极展开范围、输出功率、治疗时间的方法，造成肿瘤残存。应用免疫组织化学方法检测残存肿瘤细胞在不同时间点ERCC1表达的阳性率。结果RFA组残存肿瘤组织ERCC1表达阳性率在1 d-5 d呈一过性升高（53.7%±1.6% & 32.9%±2.5%），5 d后恢复至对照组水平。结论因在RFA治疗后1 d-5 d内残存肿瘤细胞ERCC1表达增高，在此期间给予铂类药物化疗可能效果不佳。

Quantification of Excision Repair Cross-Complementing Group 1 and Survival in p16-Negative Squamous Cell Head and Neck Cancers

Multimodality treatment of squamous cell carcinoma of the head and neck (SCCHN) often involves radiotherapy and cisplatin-based therapy. Elevated activity of DNA repair mechanisms, such as the nucleotide excision repair (NER) pathway, of which ERCC1 is a rate-limiting element, are associated with cisplatin and possibly RT resistance. We have determined excision repair cross-complementing group 1 (ERCC1) expression in human papillomavirus (HPV)-negative SCCHN treated with surgery [± adjuvant radiotherapy/chemoradiation (CRT)]. We assessed ERCC1 protein expression in archival tumors using immunofluorescence staining and automatic quantitative analysis (AQUA) with three antibodies to ERCC1 (8F1, FL297, and HPA029773). Analysis with Classification and Regression Tree (CART) methods ascertained the cutoff points between high/low ERCC1 expression. Multivariable analysis adjusted for age, T, and N stage. Kaplan-Meier curves determined median survival. ERCC1 expression at initial tumor presentation and in recurrent disease were compared. Performance characteristics of antibodies were assessed. ERCC1 low/high groups were defined on the basis of AQUA analysis with 8F1/2009, FL297, and HPA029773. Among patients treated with surgery plus adjuvant radiotherapy/CRT, longer median survival was observed in ERCC1-low versus ERCC1-high tumors (64 vs. 29 months; P = 0.02; HPA029773). Data obtained with HPA029773 indicated no survival difference among patients treated only with surgery. Recurrent cancers had lower ERCC1 AQUA scores than tumors from initial presentation. Extensive characterization indicated optimal specificity and performance by the HPA029773 antibody. Using AQUA, with the specific ERCC1 antibody HPA029773, we found a statistical difference in survival among high/low-ERCC1 tumors from patients treated with surgery and adjuvant radiotherapy.

ERCC1 function in nuclear excision and interstrand crosslink repair pathways is mediated exclusively by the ERCC1-202 isoform

ERCC1 (excision repair cross-complementation group 1) plays essential roles in the removal of DNA intrastrand crosslinks by nucleotide excision repair, and that of DNA interstrand crosslinks by the Fanconi anemia (FA) pathway and homology-directed repair processes (HDR). The function of ERCC1 thus impacts on the DNA damage response (DDR), particularly in anticancer therapy when DNA damaging agents are employed. ERCC1 expression has been proposed as a predictive biomarker of the response to platinum-based therapy. However, the assessment of ERCC1 expression in clinical samples is complicated by the existence of 4 functionally distinct protein isoforms, which differently impact on DDR. Here, we explored the functional competence of each ERCC1 protein isoform and obtained evidence that the 202 isoform is the sole one endowed with ERCC1 activity in DNA repair pathways. The ERCC1 isoform 202 interacts with RPA, XPA, and XPF, and XPF stability requires expression of the ERCC1 202 isoform (but none of the 3 others). ERCC1-deficient non-small cell lung cancer cells show abnormal mitosis, a phenotype reminiscent of the FA phenotype that can be rescued by isoform 202 only. Finally, we could not observe any dominant-negative interaction between ERCC1 isoforms. These data suggest that the selective assessment of the ERCC1 isoform 202 in clinical samples should accurately reflect the DDR-related activity of the gene and hence constitute a useful biomarker for customizing anticancer therapies.

Class III β-tubulin is a predictive marker for taxane-based chemotherapy in recurrent and metastatic gastric cancer

BackgroundClass III β-tubulin (TUBB3) is a prognostic marker in various tumors, but the role of TUBB3 in advanced gastric cancer is not clearly defined. We analyzed the significance of TUBB3 expression, along with that of excision repair cross-complementation group 1 (ERCC1) in recurrent and metastatic gastric cancer patients receiving taxane-based first-line palliative chemotherapy.MethodsWe reviewed the cases of 146 patients with advanced gastric adenocarcinoma who received taxane-based first-line palliative chemotherapy between 2004 and 2010 at Chonnam National University Hwasun Hospital (Gwangju, Korea). Immunohistochemical staining for TUBB3 and ERCC1 was performed using paraffin wax-embedded tumor tissues. We evaluated the patients’ response to chemotherapy, progression-free survival (PFS), and overall survival (OS).ResultsIn total, 146 patients with advanced gastric cancer received docetaxel and cisplatin (n = 15) or paclitaxel and cisplatin (n = 131). The median PFS was significantly shorter for patients with high-level TUBB3 expression than for patients with low-level TUBB3 expression (3.63 vs. 6.67 months, P = 0.001). OS was not associated with TUBB3 expression (13.1 vs. 13.1 months, P = 0.769). By multivariate analysis, only TUBB3 was related to a shorter PFS (HR 2.74, 95% CI 1.91-3.91, P = 0.001). Patients with high-level ERCC1 expression showed a lower response rate than patients with low-level ERCC1 expression (24 vs. 63.2%, P = 0.001); however, ERCC1 had no clinical effect on PFS or OS.ConclusionsTUBB3 was a strong predictive marker in recurrent and metastatic gastric cancer patients receiving taxane-based first-line palliative chemotherapy. No clinical impact of ERCC1 was evident in this setting.

A high-throughput screen identifies PARP1/2 inhibitors as a potential therapy for ERCC1-deficient non-small cell lung cancer

Excision repair cross-complementation group 1 (ERCC1) is a DNA repair enzyme that is frequently defective in non-small cell lung cancer (NSCLC). Although low ERCC1 expression correlates with platinum sensitivity, the clinical effectiveness of platinum therapy is limited, highlighting the need for alternative treatment strategies. To discover new mechanism-based therapeutic strategies for ERCC1-defective tumours, we performed high-throughput drug screens in an isogenic NSCLC model of ERCC1 deficiency and dissected the mechanism underlying ERCC1-selective effects by studying molecular biomarkers of tumour cell response. The high-throughput screens identified multiple clinical poly (ADP-ribose) polymerase 1 and 2 (PARP1/2) inhibitors, such as olaparib (AZD-2281), niraparib (MK-4827) and BMN 673, as being selective for ERCC1 deficiency. We observed that ERCC1-deficient cells displayed a significant delay in double-strand break repair associated with a profound and prolonged G₂/M arrest following PARP1/2 inhibitor treatment. Importantly, we found that ERCC1 isoform 202, which has recently been shown to mediate platinum sensitivity, also modulated PARP1/2 sensitivity. A PARP1/2 inhibitor-synthetic lethal siRNA screen revealed that ERCC1 deficiency was epistatic with homologous recombination deficiency. However, ERCC1-deficient cells did not display a defect in RAD51 foci formation, suggesting that ERCC1 might be required to process PARP1/2 inhibitor-induced DNA lesions before DNA strand invasion. PARP1 silencing restored PARP1/2 inhibitor resistance in ERCC1-deficient cells but had no effect in ERCC1-proficient cells, supporting the hypothesis that PARP1 might be required for the ERCC1 selectivity of PARP1/2 inhibitors. This study suggests that PARP1/2 inhibitors as a monotherapy could represent a novel therapeutic strategy for NSCLC patients with ERCC1-deficient tumours.

Effect of TUBB3, TS and ERCC1 mRNA expression on chemoresponse and clinical outcome of advanced gastric cancer by multiplex branched-DNA liquid chip technology

To analyze the impact of β-tubulin-III (TUBB3), thymidylate synthase (TS) and excision repair cross complementation group 1 (ERCC1) mRNA expression on chemoresponse and clinical outcome of patients with advanced gastric cancer treated with TXT/CDDP/FU (DCF) regimen chemotherapy. The study population consisted of 48 patients with advanced gastric cancer. All patients were treated with DCF regimen palliative chemotherapy. The mRNA expressions of TUBB3, TS and ERCC1 of primary tumors were examined by multiplex branched-DNA liquid chip technology. The patients with low TUBB3 mRNA expression had higher response rate to chemotherapy than patients with high TUBB3 expression (P=0.011). There were no significant differences between response rate and TS or ERCC1 expression pattern. Median overall survival (OS) and median time to progression (TTP) were significantly longer in patients with low TUBB3 mRNA expression (P=0.002, P<0.001). TS or ERCC1 expression was not correlated with TTP and OS. In the combined analysis including TUBB3, TS and ERCC1, the patients with 0 or 1 high expression gene had better response rate, TTP and OS than the remaining patients (all P<0.001). Multivariate analysis revealed that ECOG (Eastern Cooperative Oncology Group)≥2 (HR=2.42, P=0.009) and TUBB3 (HR=2.34, P=0.036) mRNA expression significantly impacted on OS. High TUBB3 mRNA expression is correlated with resistance to DCF regimen chemotherapy. TUBB3 might be a predictive and prognostic factor in patients with advanced gastric cancer treated with TXT-based chemotherapy. The combined evaluation of TUBB3, TS and ERCC1 expression can promote the individual treatment in advanced gastric cancer.

Ribonucleotide reductase subunit-2 (RRM2) and thymidylate synthase (TS) to predict shorter survival in patients (pts) with resected stage I-III non-small cell lung cancer (NSCLC).

11063 Background: Tumor biomarkers can help to identify pts with early-stage NSCLC with high risk of relapse and poor prognosis. The aim of this study was to investigate the prognostic value of 7 biomarkers involved in DNA synthesis and repair. Methods: Tumour tissues from 82 radically resected, stage I-III NSCLC pts were consecutively collected to investigate the following biomarkers: excision repair cross-complementation group 1 (ERCC1), breast cancer 1 (BRCA1), ribonucleotide reductase subunit 1 (RRM1), ribonucleotide reductase subunit 2 (RRM2), subunit p53R2, thymidylate synthase (TS) and class III beta-tubulin (TUBB3) using immunohistochemistry (IHC) and quantitative real time-polymerase chain reaction (qRT-PCR). Expression levels of these genes were also investigated in a large publicly available NSCLC microarray dataset (Director Challenge Consortium, DCC). Results: RRM2 expression (p=0.031), TS expression (p=0.023), and pathologic stage (p&lt;0.001) were found as independent prognostic factors for shorter survival. The expression of ERCC1, RRM1, p53R2, TUBB3, BRCA1, as well as other clinical characteristics, failed to show any statistically significant association with the survival. Despite the lack of statistical significance, patients with lower RRM2 expression (i.e., ≤ 140) survived longer than pts with higher RRM2 levels (p=0.069). There was a trend towards longer survival for BRCA1-, ERCC1-, RRM1- and TS-negative pts and for p53R2- and TUBB3-positive pts. For all of the biomarkers except TUBB3, the OS trends relative to the protein expression levels were in agreement with those relative to the respective gene expression levels, although the differences were not statistically significant. In the larger DCC dataset, TS (p=0.005), and BRCA1 (p=0.021) were identified as prognostic markers for OS, independent of tumour stage. Conclusions: This study has shown that high RRM2 and TS protein levels are negative prognostic factors for resected, stage I-III NSCLC pts. The data obtained by qRT-PCR confirmed these results. Analysis of the DCC microarray dataset detected TS and BRCA1 as independent prognostic markers of OS.

Analysis of HPV and ERCC1 in recurrent or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN).

6006 Background: We studied the association of human papillomavirus (HPV) and excision repair cross-complementation group 1 (ERCC1) tumor expression with clinical outcomes in patients (pts) with R/M SCCHN. Methods: Archival baseline specimens were obtained from pts on ECOG trials: E1395, phase III trial of cisplatin/paclitaxel (CP) vs. cisplatin/5-FU (CF), and E3301, phase II trial of docetaxel/irinotecan. HPV DNA was detected by in situ hybridization (ISH) with a wide spectrum HPV probe. Tumor p16 status was defined as positive if immunohistochemical staining for p16 was strong and present in &gt;80% of tumor cells. ERCC1 expression was measured (HistoRx PM-2000) and data analyzed using AQUA algorithms, after tissue was stained with ERCC1 ab (1:5000 HPA0297731, Sigma), and a wide-spectrum cytokeratin ab (Dako Z0622) for tumor mask. A prior determined cut point for nuclear staining was utilized. Fisher's exact test and log-rank test were used to compare categorical variables and survival. Stratified logistic regression and Cox regression model were used to estimate odds ratio (OR) and hazard ratio (HR), respectively, adjusting for potential confounding factors. p-values were two-sided. Results: Tissue was evaluable from 65 tumors (T) for HPV, 66 for p16 (E1395 and E3301), and 43 for ERCC1 expression (E1395). 11 T were HPV+ (12 p16+), and 54 were HPV-/p16-. HPV+ tumors were similarly represented in all treatment groups (p=0.58). Objective response rates (RR): 67% for HPV+, 22% for HPV- (p=0.013); 60% p16+, 22% p16- (p=0.05). RR rates were calculated excluding cases with unevaluable/unknown responses. HR for OS was 2.66 (HPV, p=0.02) and 2.27 (p16, p=0.04), favoring HPV+/p16+ pts. 18 T were ERCC1 high (H) and 25 ERCC1 low (L). HR for OS (H vs. L) was 1.96 (p=.11) RR: CF, 58% (L), 29% (H); CP, 33% (L), 56% (H). A test of ERCC1 by treatment interaction (p=0.12) suggested the effect of ERCC1 may be different for taxane vs. non-taxane regimens. Conclusions: This is the first study to show that HPV+/p16+ status is associated with a significant improvement in RR and OS among pts treated for R/M SCCHN. ERCC1 L was associated with a trend towards a better OS.

Intratumour variation of biomarker expression by immunohistochemistry in resectable non-small cell lung cancer

BackgroundPrognostic and predictive biomarkers are increasingly used to customise the treatment of patients with solid tumours. Intra- and inter-tumour heterogeneous distribution of biomarker expression is a potential confounder for the use of biomarkers, as small biopsies may not necessarily truly reflect the pattern of biomarker expression. It may also be an important factor in chemo resistance, as tumours with heterogeneous biomarker expression may potentially harbour chemo resistant tumour clones. Materials and MethodsImmunohistochemical evaluation of the expression of excision repair cross complementation group 1 (ERCC1), epidermal growth factor receptor (EGFR), class III-β-tubulin (TUBB-3), thymidylate synthase (TS), Ki-67 and ribonucleotide reductase M1 (RRM1) was performed in 15 separate areas in each of six small microscopically completely resected adenocarcinomas of the lung in order to elucidate any heterogeneous distribution. ResultsClinically relevant biomarker heterogeneity with respect to the expression of EGFR, ERCC1, RRM1, TUBB-3 and Ki-67 was observed in four (66%), four (66%), one (16%), three (50%) and five (83%) out of six tumours, respectively. Thus, heterogeneity could potentially allocate these tumours erroneously into high or low expressers by chance alone, according to previously reported cut-off values. In contrast, TS was almost completely homogenously distributed. ConclusionMost biomarkers examined, except for TS, showed clinically significant intratumour heterogeneity in 33–87% of tumours examined. This heterogeneity may influence results in studies investigating the therapeutic impact of predictive biomarkers in non-small cell lung cancer (NSCLC).

Abstract 3472: Excision repair cross complementing group 1 (ERCC1) and regulatory subunit of Ribonucleotide Reductase (RRM1) as prognostic and predictive markers for ovarian cancer.

Abstract Background: Ninety percent of ovarian cancers are epithelial in nature (EOC); the standard approach for treatment is surgery followed by platinum and taxane based chemotherapy. Gemcitabine has been evaluated recently in combination with platinum and taxane for platinum sensitive recurrence and as a single agent for platinum refractory or resistant recurrent EOC. ERCC1 and RRM1 are involved in DNA synthesis and repair derived from genotoxic stress, and they have also been reported as predictive markers for therapeutic efficacy in patients with lung and pancreatic cancers. Their expression, association and clinical significance in ovarian carcinoma remain uncertain. Design: 198 archived cases of epithelial cell ovarian cancer were reviewed and divided into three subtypes: borderline tumor (BLT), Type I and Type II. 2mm TMAs were developed with duplicate cores per case. Immunofluorescence combined with Automated Quantitative Analysis (AQUA) was used to assess the expression of ERCC1 and RRM1. The average of duplicate cores was used for analysis and Greedy search was used for establishing the high and low score cutoff points. Results: 44 cases (22%) were BLT, 29 (15%) were Type I tumors, 121 (61%) were Type II tumors, and 4 cases (4%) were unclassified. Type II tumors were significantly higher among elderly Caucasian women (p&amp;lt;0.001) as compared to African American women. Kaplan Meier curves showed no statistically significant difference in overall survival (OS) between Type I and Type II cancers. Low ERCC1 scores were significantly associated with lower OS rates (hazard ratio (HR) = 1.46), when compared with high ERCC1 scores. In contrast, low RRM1 scores were associated with better overall survival (HR = 0.36). Scores for both markers were not significantly associated with tumor type, histology grade or stage. On multivariate analysis including ERCC1, RRM1, tumor stage, tumor type, age and race; only age and tumor type (BLT I&amp;II) persisted as independent prognostic factors for poor overall survival. Conclusion: Our study suggests that low expression of ERCC1 and high expression of RRM1 are associated with poor survival in ovarian cancer patients. Large studies are warranted to elucidate whether or not the expression of ERCC1 and RRM1 can be used as prognostic or predictive markers. Citation Format: Jun Zhou, Quratulain Ahmed, Wei Chen, Xin Li, Robert Morris, Rouba Ali-Fehmi, Gerold Bepler. Excision repair cross complementing group 1 (ERCC1) and regulatory subunit of Ribonucleotide Reductase (RRM1) as prognostic and predictive markers for ovarian cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3472. doi:10.1158/1538-7445.AM2013-3472

Thymidylate synthase and ERCC1 as predictive markers in patients with pulmonary adenocarcinoma treated with pemetrexed and cisplatin

Increased expression of thymidylate synthase (TS) is thought to be associated with resistance to antifolate drugs such as pemetrexed. Excision repair cross-complementation group 1 (ERCC1) is a predictive marker for platinum-based chemotherapy. This study evaluated whether the expression of TS and ERCC1 proteins is associated with clinical outcomes of the patients with pulmonary adenocarcinoma who were treated with pemetrexed/cisplatin as first-line chemotherapy. The expressions of TS and ERCC1 were evaluated by immunohistochemistry in biopsy specimens obtained from patients with pulmonary adenocarcinoma who had received pemetrexed/cisplatin as first-line treatment. Patients were categorized according to median H-score. Response rate (RR), progression-free survival (PFS) and overall survival (OS) were analyzed retrospectively. Both low TS and ERCC1 expressions were significantly associated with better RR (p=0.037 and p=0.015, respectively) and longer PFS (p<0.001 and p=0.004, respectively). Low ERCC1 expression was also associated with longer OS (p=0.003) while TS only showed a trend (p=0.105). TS expression was independent predictor for the better PFS in multivariate analysis (hazard ratio [HR]=0.32, 95% confidence interval [CI]: 0.14–0.76). Combining the two markers, the low TS/low ERCC1 group showed significantly longer PFS (HR=0.48, 95% CI: 0.26–0.75) and OS (HR=0.57, 95% CI: 0.36–0.89) compared with high TS/high ERCC1 group.Protein expressions of TS and ERCC1 were associated with clinical outcomes in patients with pulmonary adenocarcinoma who were treated with pemetrexed/cisplatin as first-line chemotherapy. TS and ERCC1 protein expressions can be potential predictive markers in this setting.

ERCC1 Isoform Expression and DNA Repair in Non–Small-Cell Lung Cancer

BackgroundThe excision repair cross-complementation group 1 (ERCC1) protein is a potential prognostic biomarker of the efficacy of cisplatin-based chemotherapy in non–small-cell lung cancer (NSCLC). Although several ongoing trials are evaluating the level of expression of ERCC1, no consensus has been reached regarding a method for evaluation.MethodsWe used the 8F1 antibody to measure the level of expression of ERCC1 protein by means of immunohistochemical analysis in a validation set of samples obtained from 494 patients in two independent phase 3 trials (the National Cancer Institute of Canada Clinical Trials Group JBR.10 and the Cancer and Leukemia Group B 9633 trial from the Lung Adjuvant Cisplatin Evaluation Biology project). We compared the results of repeated staining of the entire original set of samples obtained from 589 patients in the International Adjuvant Lung Cancer Trial Biology study, which had led to the initial correlation between the absence of ERCC1 expression and platinum response, with our previous results in the same tumors. We mapped the epitope recognized by 16 commercially available ERCC1 antibodies and investigated the capacity of the different ERCC1 isoforms to repair platinum-induced DNA damage.ResultsWe were unable to validate the predictive effect of immunostaining for ERCC1 protein. The discordance in the results of staining for ERCC1 suggested a change in the performance of the 8F1 antibody since 2006. We found that none of the 16 antibodies could distinguish among the four ERCC1 protein isoforms, whereas only one isoform produced a protein that had full capacities for nucleotide excision repair and cisplatin resistance.ConclusionsImmunohistochemical analysis with the use of currently available ERCC1 antibodies did not specifically detect the unique functional ERCC1 isoform. As a result, its usefulness in guiding therapeutic decision making is limited. (Funded by Eli Lilly and others.)