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.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Clinical Role of Excision Repair Cross-Complementing 1 Gene Expression in Resected Esophageal Squamous Cell Carcinoma: A Meta-Analysis.

AIMS: To explore the relationship between excision repair cross-complementing 1 (ERCC1) gene expression and clinical pathological parameters and prognosis of esophageal squamous cell carcinoma (ESCC) patients who received the surgical therapy. METHODS: To identify relevant articles, a systematic literature retrieval was conducted in several databases, including the Embase, Web of Science, Cochrane Library, PubMed, VIP, Wanfang, and CNKI. The association of ERCC1 gene expression with clinicopathological characteristics and survival was assessed by the pooled relative risk (RR) and hazard ratio (HR) with the corresponding 95% confidence interval (CI), respectively. Sensitivity analysis was conducted to assess the stability of pooled results. Begg's funnel plot and Egger's test were applied to detect potential publication bias. RESULTS: A total of nine studies involving 746 patients were included in our meta-analysis, and all patients were from Asian countries, including China, Korea, and Japan. The results indicated that ERCC1 gene expression was significantly associated with lymph node metastasis (RR = 1.30, 95% CI 1.11-1.53; P = 0.002), higher TNM stage (RR = 1.23, 95% CI 1.06-1.43; P = 0.006), worse overall survival (HR = 2.40, 95% CI 1.32-4.37; P < 0.001), and disease-free survival (HR = 1.67, 95% CI 1.15-2.41; P = 0.007). Sensitivity analysis manifested that the pooled results were stable and no significant publication bias was observed. CONCLUSIONS: ERCC1 gene expression is significantly related to tumor stage and prognosis in resected ESCC patients from Asian countries. More prospective studies with larger samples are needed to testify our findings.

Clinical research of individualized therapy in advanced esophageal cancer based on the ERCC1 C8092A genotype.

The present study aimed to explore the role and clinical value of the detection of Excision repair cross-complementing 1(ERCC1) C8092A polymorphisms in individualized therapy of patients with advanced esophageal cancer. A total of 127 patients with advanced esophageal cancer were enrolled between January 2010 and January 2014 in Anhui Provincial Hospital. Patients were randomly assigned in a 1:2 ratio to a standard treatment group or an individualized treatment group, respectively, prior to ERCC1 C8092A assessment. Patients in the standard treatment group were treated with paclitaxel and cisplatin. The DNA was obtained from the peripheral blood of individualized treatment patients, amplified by PCR and sequenced to determine the ERCC1 C8092A polymorphism prior to the administration of chemotherapies. Patients with the ERCC1 C8092A genotype of A/A or A/C received paclitaxel and cisplatin, and those with the genotype of C/C received paclitaxel and fluorouracil. The primary endpoint was response rate (RR). The secondary endpoints included toxicity of chemotherapy, progression-free survival (PFS) and overall survival (OS) times. Differences between the groups were evaluated by χ2 test. Differences in survival were analyzed by Kaplan-Meier survival curves. The survival rate was analyzed by log-rank test. Follow-up data was obtained until December 2015. The RR was obtained for 15 patients (34.8%) in the standard treatment group and 45 patients (53.6%) in the individualized treatment group (χ2=3.095; P=0.046). For adverse events, nausea and vomiting and anemia were significantly decreased in the individualized treatment group compared with the standard treatment group (P=0.001 and P=0.004, respectively). The median progression free survival time was 4.4 months [95% confidence interval (CI)3.8-5.0 months] in the standard treatment group and 6.6 months (95% CI, 5.8-7.4 months) in the individualized treatment group (P=0.018). The median overall survival time was 11.4 months (95% CI, 10.1-12.7 months) in the standard treatment group and 14.2 months (95% CI, 13.2-15.2 months) in the individualized treatment group (P=0.008). The RR, toxicity of chemotherapy, PFS and OS were significantly improved in the individualized treatment group compared with the standard treatment group. Detection of ERCC1 gene polymorphisms maybe performed for patients with advanced esophageal cancer to improve individualized therapy, which requires additional study.

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.

Overexpression of ribonucleotide reductase subunit M1 protein predicts shorter survival in metastatic bladder cancer patients treated with gemcitabine-containing combination chemotherapy.

OBJECTIVES: To identify biomarkers predicting prognosis in bladder cancer patients undergoing the gemcitabine and cisplatin regimen. METHODS: We studied 52 patients with metastatic bladder cancer treated with the gemcitabine and cisplatin regimen by evaluating the relationship between the expression of two biomarkers, ribonucleotide reductase subunit M1 and excision repair cross complementing 1, by immunohistochemistry and clinical outcomes. RESULTS: The patients with low expression of ribonucleotide reductase subunit M1 showed a higher objective response rate by the gemcitabine and cisplatin regimen than those with high expression of ribonucleotide reductase subunit M1 (80.0% and 45.5%, respectively). No differences were observed according to the expression level of excision repair cross complementing 1. Low expression of ribonucleotide reductase subunit M1 significantly prolonged overall survival and progression-free survival compared with the high expression group. Low expression of excision repair cross complementing 1 tended to prolong overall survival and progression-free survival, but there were no significant differences (P = 0.07 and 0.10, respectively). Multivariate analysis showed that the expression of ribonucleotide reductase subunit M1 was the only independent prognostic factor (P = 0.012). CONCLUSIONS: The expressions of ribonucleotide reductase subunit M1 seem to be associated with clinical response and survival in patients with metastatic bladder cancer treated with gemcitabine and cisplatin-based chemotherapy.

Prognostic role of excision repair cross complementing-1 and topoisomerase-1 expression in epithelial ovarian cancer.

OBJECTIVE: Epithelial ovarian cancer is the most lethal gynecologic cancer worldwide and chemoresistance is one of the major causes of treatment failure. We investigated whether ERCC1, TAU, TOPO2A, TOPO1, P53, and C-MYC expression could be used as predictors for treatment outcomes. MATERIALS AND METHODS: Immunohistochemical staining was used to examine the expression of these biomarkers in resected tumor specimens from 38 patients treated in our institute. Clinicopathological data including demographics, staging, histological type, treatment response, expression of the biomarkers, and patient outcomes were analyzed. RESULTS: The median follow-up period was 47.5 months (range, 10-135 months) and the median overall survival was 56.0 months. Patients who did not have expression of ERCC1, and those who had expression of TOPO1 had significantly better overall survival. Cox regression analysis also confirmed that these two biomarkers were significant independent factors predicting survival (ERCC1, hazard ratio 5.51, 95% confidence interval: 2.02-14.00, p = 0.001; TOPO1, hazard ratio 0.22, 95% confidence interval: 0.06-0.77, p = 0.017). CONCLUSION: We concluded that poor overall survival was significantly associated with positive ERCC1 and negative TOPO1 expression. The results might be the consequence of chemoresistance to platinum and camptothecins, both of which are commonly used regimens in the treatment of epithelial ovarian cancer.

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 ß-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.

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.

Gene expression profiling for analysis acquired oxaliplatin resistant factors in human gastric carcinoma TSGH-S3 cells: the role of IL-6 signaling and Nrf2/AKR1C axis identification.

Oxaliplatin treatment is a mainstay of treatment for advanced gastrointestinal tract cancer, but the underlying mechanisms of acquired oxaliplatin resistance remain largely obscured. We previously demonstrated that increased DNA repair capacity and copper-transporting ATPase 1 (ATP7A) level contributed to oxaliplatin resistance in the human gastric carcinoma cell line TSGH-S3 (S3). In the present study, we applied gene array technology to identify additional resistance factors in S3 cells. We found that interleukin-6 (IL-6), aldo-keto reductase 1C1 (AKR1C1), and AKR1C3 are the top 3 upregulated genes in S3 cells when compared with parent TSGH cells. Despite a higher level of endogenous IL-6 in S3, IL-6 receptor (IR-6R, gp-80, and gp-130) levels were similar between TSGH and S3 cells. The addition of exogenous IL-6, IL-6 targeted siRNA, or neutralizing antibodies neither affected Stat3 activation, a downstream target of IL-6, nor changed oxaliplatin sensitivity in S3 cells. However, manipulation of AKR1C activity with siRNA or AKR1C inhibitors significantly reversed oxaliplatin resistance. AKR1Cs are classical antioxidant response element (ARE) genes that can be transcriptionally upregulated by nuclear factor erythroid 2-related factor 2 (Nrf2). Knockdown of Nrf2 not only decreased the levels of AKR1C1, AKR1C2, and AKR1C3 mRNA and protein but also reversed oxaliplatin resistance in S3 cells. Taken together, these results suggest that activation of the Nrf2/AKR1C axis may contribute to oxaliplatin resistance in S3 cells but that the IL-6 signaling pathway did not contribute to resistance. Manipulation of Nrf2/AKR1Cs activity may be useful for management of oxaliplatin-refractory gastric cancers.

19q13-ERCC1 gene copy number increase in non--small-cell lung cancer.

BACKGROUND: Excision repair cross complementing 1 gene expression level has potential as a prognostic and predictive marker of the efficacy of chemotherapy in NSCLC. The effect of ERCC1 gene copy number (CN) variation (CNV) on ERCC1 expression and the clinical outcome of patients with NSCLC are not known. MATERIALS AND METHODS: Copy number variation of the 19q13.3 region carrying the ERCC1 gene, classified as gene amplification (GA) or high polysomy (HP), was evaluated on 235 formalin-fixed and paraffin-embedded tumors from resected NSCLC patient samples and 16 NSCLC cell lines using FISH. We analyzed the potential correlations between FISH status and ERCC1 expression, patient's outcome, and cisplatin sensitivity in the cohort or cell lines. RESULTS: An increase of 19q13.3 gene CN was detected in 60 cases (25.5%) including 27 cases with GA and 33 cases with HP. A nonsignificant trend for higher ERCC1 expression in HP patients compared with GA and patients with low CNV was found (P = .06). In patients not treated with chemotherapy, FISH negative status cases had longer disease-free survival (DFS) compared with patients with 19q13-ERCC1 GA (P = .02). A 3-fold increase in IC50 of cisplatin in cell lines with high 19q13-ERCC1 CN compared with cells without CNV was shown. CONCLUSION: ERCC1 CN increase assessed using FISH did not determine ERCC1 expression status but yields potential prognostic information on DFS in untreated patients with NSCLC. The clinical relevance of an association of 19q13-ERCC1 FISH status and chemosensitivity or prognosis in patients needs further investigation and validation.

DNA repair mechanisms in dividing and non-dividing cells.

DNA damage created by endogenous or exogenous genotoxic agents can exist in multiple forms, and if allowed to persist, can promote genome instability and directly lead to various human diseases, particularly cancer, neurological abnormalities, immunodeficiency and premature aging. To avoid such deleterious outcomes, cells have evolved an array of DNA repair pathways, which carry out what is typically a multiple-step process to resolve specific DNA lesions and maintain genome integrity. To fully appreciate the biological contributions of the different DNA repair systems, one must keep in mind the cellular context within which they operate. For example, the human body is composed of non-dividing and dividing cell types, including, in the brain, neurons and glial cells. We describe herein the molecular mechanisms of the different DNA repair pathways, and review their roles in non-dividing and dividing cells, with an eye toward how these pathways may regulate the development of neurological disease.