Current status of excision repair cross complementing-group 1 (ERCC1) in cancer

MicroRNA-409: Molecular functions and clinical applications in cancer

Late diagnosis is one of the main reasons for high mortality rates in cancer patients. Therefore, investigating the molecular mechanisms involved in tumor progression can improve the cancer diagnosis in the early stages of the tumor progression. MicroRNAs (miRNAs) have important roles in regulation of cell growth, proliferation, metabolism, and migration. Since, deregulation of miR-409 has been reported in a wide range of cancers, in the present review, we investigated the molecular mechanisms of miR-409 during tumor progression and invasion. It has been shown that miR-409 functions as a tumor suppressor in different tumor types. MiR-409 can reduce tumor cell proliferation, growth, and migration by regulation of signaling pathways, cellular metabolism, transcription factors, and cellular adhesion. This review can be an effective step in introducing miR-409 as a non-invasive marker in cancer patients.

Relationship between ERCC1 and XPC polymorphisms and the susceptibility to head and neck carcinoma: A systematic review, meta-analysis, and trial sequential analysis

OBJECTIVE

This meta-analysis was conducted to investigate the relationship between ERCC1 and XPC polymorphisms and the risk of head and neck cancer (HNC), incorporating more studies and additional analyses.

DESIGN

An exhaustive search of various databases, including PubMed/Medline, Web of Science, Scopus, and Cochrane Library was carried out, up until November 18, 2023, to identify pertinent studies. The Review Manager 5.3 software was employed to calculate the effect sizes, which were presented as the odds ratio (OR) along with a 95% confidence interval (CI).

RESULTS

The study found that the T allele (OR = 1.11; p-value = 0.02; 95%CI: 1.02, 1.22) and the TT genotype rs2228000 polymorphism in both the homozygous model (OR = 1.61, p-value = 0.02; 95%CI: 1.07, 2.42) and the recessive model (OR = 1.53; p-value = 0.02; 95%CI: 1.06, 2.22) had statistically significant associations. However, no significant associations were found for rs11615, rs3212986, rs735482, rs2228001, and PAT polymorphisms in any genetic models.

CONCLUSIONS

The meta-analysis revealed significant associations for the T allele and TT genotype rs2228000 polymorphism, but not for rs11615, rs3212986, rs735482, rs2228001, and PAT polymorphisms. The results highlight the impact of factors such as ethnicity, cancer subtype, and control source on these associations, emphasizing the intricate nature of genetic interactions in disease risk.

DNA Damage Repair Proteins, HSP27, and Phosphorylated-HSP90α as Predictive/Prognostic Biomarkers of Platinum-based Cancer Chemotherapy: An Exploratory Study

Platinum analogs are commonly used for cancer treatment. There is increasing interest in finding biomarkers which could predict and overcome resistance, because to date there is no reliable predictive/prognostic marker for these compounds. Here we studied the immunohistochemical expression of proteins involved in DNA damage response and repair (γH2AX, 53BP1, ERCC1, MLH1, and MSH2) in primary tumor tissues from patients treated with platinum-based chemotherapy. Levels and localization of Heat Shock Protein (HSP)27 and phospho-(Thr5/7)-HSP90α (p-HSP90α) were also determined. The implications in clinical response, disease-free survival and overall survival were analyzed. High γH2AX and 53BP1 expressions were associated with poor clinical response. Nuclear p-HSP90α, as well as nuclear absence and low cytoplasmic expression of HSP27 correlated with good response. Patients with high γH2AX and high cytoplasmic HSP27 expressions had shorter overall survival and disease-free survival. MLH1, MSH2, or ERCC1 were not associated with clinical response or survival. We report the potential utility of p-HSP90α, HSP27, γH2AX, and 53BP1 as predictive/prognostic markers for platinum-based chemotherapy. We present the first study that evaluates the predictive and prognostic value of p-HSP90α in primary tumors. Our research opens new possibilities for clinical oncology and shows the usefulness of immunohistochemistry for predicting chemotherapy response and prognosis in cancer.

Targeted nanomedicine in cisplatin-based cancer therapeutics

Since its license in 1978, cisplatin has proved to be one of the most successful chemotherapeutic agents in the world. However, two acute challenges facing cisplatin, resistance and toxicity, have resulted in a bottleneck of clinical application. Targeted nanomedicine shows great promise in delivering cisplatin for maximizing efficacy while minimizing off-target toxicity. This article surveyed the recent progress and challenges of targeted nanomedicine in managing resistance and toxicity of cisplatin in both fundamental and clinical aspects. Particularly, we focused on three major mechanisms counteracting cisplatin sensitivity (decreased intracellular accumulation, increased cisplatin deactivation, and enhanced DNA repair/translesion synthesis) and correspondingly highlighted a few representative approaches to increase cisplatin sensitivity through improving the intracellular concentration of cisplatin and implementing combination therapy. Moreover, the requirements for future advancements in cisplatin delivery systems are rendered with emphasis on (i) understanding of nano-bio interaction and post-accumulation biological effects instead of overwhelmingly improving tumor accumulation, (ii) development of stimuli-responsive and/or actively-targeted nanomedicines, (iii) optimization of combination therapy, (iv) novel combinations targeting tumor microenvironment and immunotherapy. We postulate that cisplatin-based nanomedicines will continuously advance and potentially revolutionize oncological treatment.

Validation of Potential Protein Markers Predicting Chemoradioresistance in Early Cervical Cancer by Immunohistochemistry

Background

In a previous study, a proteomic panel consisting of BCL-2, HER2, CD133, CAIX, and ERCC1 significantly predicted survival in patients with locally advanced cervical cancer. However, the prognostic significance of these proteins has not been assessed in early cervical cancer. The present study investigated the clinical significance and chemoradioresistance prediction power of these proteins in patients with early-stage cervical cancer.

Materials and Methods

BCL-2, HER2, CD133, CAIX, and ERCC1 expression was determined by the immunohistochemical staining of 336 cervical cancer tissue microarrays. The associations of these proteins with clinicopathologic characteristics and disease progression were assessed.

Results

There was a trend of low CAIX expression (p=0.082) and high ERCC1 expression (p=0.059) in patients with a favorable response to adjuvant radiation. High HER2 expression was significantly associated with shorter disease-free survival (DFS) in the total group (5-year DFS of 80.1% vs. 92.2%, p=0.004). A prognostic significance remained in multivariate analysis (Hazard ratio, HR=2.10, p=0.029). In the adjuvant radiation group, low CAIX and high ERCC1 expression indicated significantly unfavorable DFS (75.0% vs. 89.0%, p=0.026 and 76.8% vs. 88.6%, p=0.022, respectively). Low CAIX expression remained an independent prognostic marker in multivariate analysis (HR=0.45, p=0.037). The combined molecular-clinical model using random survival forest method predicted DFS with improved power compared with that of the clinical variable model (C-index 0.77 vs. 0.71, p=0.006).

Conclusion

HER2, CAIX, and ERCC1 expression can be predictive protein markers for clinical outcomes in early cervical cancer patients treated primarily with radical surgery with or without adjuvant radiation.

Expression patterns and prognostic significances of RRM1 and ERCC1 in pancreatic carcinoma and cholangiocarcinoma

BACKGROUND

Aggressive pancreatobiliary tumors often require oxaliplatin-based therapies, instead of standard gemcitabine-based therapy and biomarker studies at diagnosis to decide the appropriate therapeutic regimen. The ribonucleotide Reductase catalytic subunit M1 (RRM1) and excision repair cross-complementing gene-1 (ERCC1) are related to DNA synthesis and repair and essential in this regard. However, apart from the therapeutic benefit, their prognostic implication is controversial.

METHODS

In this retrospective study, paraffin-embedded tissue from 51 cases of pancreatic cancer and 29 cases of cholangiocarcinoma were evaluated for RRM1 and ERCC1 expression by immunohistochemical technique along with 18 control pancreatic and biliary tissues. The semiquantitatively H score was calculated based on stain distribution and stain intensities.

RESULTS

Both RRM1 and ERCC1 expression were high in tumor epithelium than in controls (RRM1: the difference was statistically significant in cholangiocarcinoma (P = 0.008); ERCC1: the difference was statistically significant both in pancreatic and cholangiocarcinoma (P < 0.05)]. However, no correlation was noted between RRM1 and ERCC1-low and high tumors with histological markers of prognosis and overall survival in these patients.

CONCLUSIONS

The present study adds further evidence against the controversy that if RRM1 and ERCC1 expression in pancreatic and biliary carcinomas have any prognostic significance apart from their proven therapeutic benefits in these tumors.

Platinum Complexes in Colorectal Cancer and Other Solid Tumors

Simple Summary

Cisplatin is successfully used for the treatment of various solid cancers. Unfortunately, it shows no activity in colorectal cancer. The resistance phenotype of colorectal cancer cells is mainly caused by alterations in p53-controlled DNA damage signaling and/or defects in the cellular mismatch repair pathway. Improvement of platinum-based chemotherapy in cisplatin-unresponsive cancers, such as colorectal cancer, might be achieved by newly designed cisplatin analogues, which retain activity in unresponsive tumor cells. Moreover, a combination of cisplatin with biochemical modulators of DNA damage signaling might sensitize cisplatin-resistant tumor cells to the drug, thus providing another strategy to improve cancer therapy.

Abstract

Cisplatin is one of the most commonly used drugs for the treatment of various solid neoplasms, including testicular, lung, ovarian, head and neck, and bladder cancers. Unfortunately, the therapeutic efficacy of cisplatin against colorectal cancer is poor. Various mechanisms appear to contribute to cisplatin resistance in cancer cells, including reduced drug accumulation, enhanced drug detoxification, modulation of DNA repair mechanisms, and finally alterations in cisplatin DNA damage signaling preventing apoptosis in cancer cells. Regarding colorectal cancer, defects in mismatch repair and altered p53-mediated DNA damage signaling are the main factors controlling the resistance phenotype. In particular, p53 inactivation appears to be associated with chemoresistance and poor prognosis. To overcome resistance in cancers, several strategies can be envisaged. Improved cisplatin analogues, which retain activity in resistant cancer, might be applied. Targeting p53-mediated DNA damage signaling provides another therapeutic strategy to circumvent cisplatin resistance. This review provides an overview on the DNA repair pathways involved in the processing of cisplatin damage and will describe signal transduction from cisplatin DNA lesions, with special attention given to colorectal cancer cells. Furthermore, examples for improved platinum compounds and biochemical modulators of cisplatin DNA damage signaling will be presented in the context of colon cancer therapy.

Pharmaceutical immunoglobulin G impairs anti-carcinoma activity of oxaliplatin in colon cancer cells

BACKGROUND

Recent evidence proves that intravenous human immunoglobulin G (IgG) can impair cancer cell viability. However, no study evaluated whether IgG application benefits cancer patients receiving chemotherapeutics.

METHODS

Influence of pharmaceutical-grade human IgG on the viability of a series of patient-derived colon cancer cell lines with and without chemotherapeutic intervention was determined. Cell death was analysed flow cytometrically. In addition, the influence of oxaliplatin and IgG on the ERK1/2-signalling pathway was evaluated by western blots.

RESULTS

We evaluated the effects of pharmaceutical IgG, such as PRIVIGEN^® IgG and Tonglu^® IgG, in combination with chemotherapeutics. We did not observe any significant effects of IgG on tumour cell viability directly; however, human IgG significantly impaired the anti-tumoral effects of oxaliplatin. Primary cancer cell lines express IgG receptors and accumulate human IgG intracellularly. Moreover, while oxaliplatin induced the activation of ERK1/2, the pharmaceutical IgG inhibited ERK1/2 activity.

CONCLUSIONS

The present study demonstrates that pharmaceutical IgG, such as PRIVIGEN^® IgG and Tonglu^® IgG, can impair the anti-carcinoma activity of oxaliplatin. These data strongly suggest that therapeutic IgG as co-medication might have harmful side effects in cancer patients. The clinical significance of these preclinical observations absolutely advises further preclinical, as well as epidemiological and clinical research.

Excision repair cross-complementing group 2 upregulation is a potential predictive biomarker for oral squamous cell carcinoma recurrence

Oral cancer is the fourth most common type of cancer among males in Taiwan, and the prognosis for patients with advanced-stage oral squamous cell carcinoma (OSCC) remains poor. The present study investigated the prognostic value of three DNA repair genes, namely excision repair cross-complementing group 1 (ERCC1), ERCC2 and X-ray repair cross-complementing group 1 (XRCC1) in OSCC. The protein expression levels of XRCC1, ERCC1 and ERCC2 in oral cell lines were analyzed via western blotting and immunohistochemistry using samples from 98 patients with biopsy-proven OSCC, while the χ² test was used to analyze the clinicopathological association. Kaplan-Meier estimates were used to determine the prognostic value of XRCC1, ERCC1 and ERCC2 for overall survival, and the log-rank test was used to evaluate the significance of differences. Multivariate analysis revealed a positive association between ERCC2 expression and OSCC recurrence (19.64-fold; 95% CI, 5.00-77.1; P<0.001). In addition, the high protein expression levels of XRCC1, ERCC1 and ERCC2 were associated with poor disease-free and overall survival rates. Therefore, the present study suggested that high ERCC2 expression may be a risk factor for OSCC recurrence.

Predictive Value of ERCC1 mRNA Level from Receiver-Operator Characteristic and Pretreatment EBV-DNA Virus Load in Stage II Nasopharyngeal Carcinoma Patients Receiving Intensity-Modulated Radiotherapy with Concurrent Cisplatin

Background: The molecular mechanisms underlying chemoresistance are still poorly understood in nasopharyngeal cancer; the protein expression of ERCC1 in DNA repair genes has been reported related to resistance platinum and predicting treatment outcomes in various malignant carcinomas, but the benefit for predicting outcomes with optimal cutoff value of ERCC1mRNA is controversial. The level of plasma Epstein-Barr virus (EBV) DNA is positively correlated with clinical stages of nasopharyngeal carcinoma (NPC). The predictive value of ERCC1mRNA from receiver-operator characteristic (ROC) and EBV-DNA level for stratified treatment with stage II NPC is exactly unclear. This study aims to assess the predictive value of combined EBV-DNA and ERCC1 in stage II nasopharyngeal cancer (NPC) patients treated with intensity-modulated radiotherapy (IMRT) with concurrent cisplatin, and provide guidance for future stratified treatment. Methods: A total of 86 stage II NPC patients who received IMRT and concurrent cisplatin-based chemotherapy with or without cisplatin-based adjuvant chemotherapy had measurements of ERCC1 mRNA, and pretreatment EBV-DNA levels were analyzed by real-time PCR (RT-PCR). Associations of ERCC1 mRNA and pretreatment EBV-DNA levels with clinical characteristics and survivals were evaluated. Results: Cutoff value of ERCC1 mRNA obtained from ROC curve was used, and there were significant differences in progression-free survival (PFS) and overall survival (OS) and overall response rate (ORR) between high expression group and low expression group (p = 0.021 and 0.030 and 0.000, respectively). Patients with pretreatment EBV-DNA <2000 copies/mL had significantly better PFS and ORR (p = 0.024 and 0.043, respectively) and a marginally significant impact on OS (p = 0.062) than those with pretreatment EBV-DNA ≥2000 copies/mL. Patients were divided into three groups by combination of ERCC1 mRNA and EBV-DNA level: ERCC1 mRNA low expression/pre-EBV-DNA <2000 copies/mL, ERCC1 mRNA low expression/pre-EBV-DNA ≥2000 copies/mL, and ERCC1 mRNA high expression/pre-EBV-DNA ≥2000 copies/mL. There were significant differences in ORR among the three groups (p = 0.005). The median follow-up was 62 months (range 22-84) with a follow-up rate of 90.70%. In these groups by combination of ERCC1 mRNA and EBV-DNA level, 1, 3, 5-year OS were 100%, 100%, 100%; 100%, 94.1%, 90.9%; and 100%, 85%, 72.9%, respectively (p = 0.038); 1, 3, 5-year PFS were 100%, 100%, 100%; 97.1%, 91.2%, 84.8%; and 95%, 85%, 71.4%, respectively (p = 0.028). Multivariate analysis showed that combination of ERCC1 mRNA and EBV-DNA levels remained independent prognostic factor but not ERCC1 mRNA and EBV-DNA alone. Conclusions: Combined ERCC1 mRNA and pre-EBV-DNA is a better prognostic biomarker in stage II NPC patients treated with concurrent chemoradiation. Patients with ERCC1 mRNA high expression/pre-EBV-DNA ≥2000 copies/mL may benefit from more aggressive treatment.

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

BACKGROUND

Recent 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.

METHODS

We 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.

RESULTS

Wild-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).

CONCLUSIONS

Our 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.

Tumor mutation burden as a biomarker for lung cancer patients treated with pemetrexed and cisplatin (the JIPANG-TR)

The JIPANG study is a randomized phase III study of pemetrexed/cisplatin (Pem/Cis) versus vinorelbine/cisplatin (Vnr/Cis) for completely resected stage II-IIIA non-squamous non-small cell lung cancer (Ns-NSCLC). This study did not meet the primary endpoint (recurrence-free survival, RFS) but Pem/Cis had a similar efficacy to Vnr/Cis with a better tolerability. Tumor mutation burden (TMB) is thought to have a predictive value of immune checkpoint inhibitors. However, the relevance of TMB to cytotoxic chemotherapy remains unknown. This exploratory study investigates the relationship between tumor mutation profiles and clinical outcome of Pem/Cis. Formalin-fixed, paraffin-embedded tumor tissues (n = 389) were obtained from the patients. Mutation status of tissue DNA was analyzed by targeted deep sequencing. Epidermal growth factor receptor (EGFR) mutations were detected frequently in Ns-NSCLC (139/374). Patients without any EGFR mutations experienced longer RFS in the Pem/Cis arm versus Vnr/Cis arms. Pem/Cis in patients with high TMB (≥12-16 mut/Mb) tended to have improved survival. In patients with wild-type EGFR, TMB ≥ 12 mut/Mb was significantly associated with improved RFS with Pem/Cis versus Vnr/Cis (not reached vs 52.5 months; hazard ratio (HR) 0.477). It could be proposed that TMB was predictive of RFS benefit with Pem/Cis versus Vnr/Cis in Ns-NSCLC. Further investigation is required to determine whether TMB combined with EGFR mutation status could be used as a predictive biomarker.

Curcumin Regulates ERCC1 Expression and Enhances Oxaliplatin Sensitivity in Resistant Colorectal Cancer Cells through Its Effects on miR-409-3p

Background

Oxaliplatin (L-OHP) resistance is a major obstacle to the effective treatment of colorectal cancer. The resistance mechanism(s) of colorectal tumors to L-OHP may be related to the regulation of ERCC1 by cancer-expressed miRNAs, but no in-depth studies on the miRNAs that affect drug resistance have been performed. Curcumin (Cur) can reverse the drug resistance of cancer cells, but its effects on ERCC1 expression and miRNA profiles in colorectal cancer have not been studied.

Methods

To study the regulation effect of curcumin on ERCC1 expression and its effects on miRNAs, the L-OHP-resistant colorectal cancer cell line HCT116/L-OHP was established. MTT assays were used to evaluate cell proliferation. Flow cytometry was used to investigate apoptotic induction. Western blot and RT-PCR analysis were used to evaluate the expression of drug-associated ERCC1, Bcl-2, GST-π, MRP, P-gp, and survivin.

Results

HCT116//L-OHP cell lines were successfully established. The combination of L-OHP and curcumin could reduce L-OHP resistance in vitro. In addition, combination therapy inhibited the expression of ERCC1, Bcl-2, GST-π, MRP, P-gp, and survivin at the mRNA and protein level. Curcumin was found to inhibit ERCC1 through its ability to modulate miR-409-3p.

Conclusion

Curcumin can overcome L-OHP resistance in colorectal cancer cells through its effects on miR-409-3p mediated ERCC1 expression.

ERCC overexpression associated with a poor response of cT4b colorectal cancer with FOLFOX-based neoadjuvant concurrent chemoradiation

Colorectal cancer (CRC) of the clinical tumor stage T4b (cT4b) refers to advanced tumors with direct invasion of adjacent structures and the tumors are considered unresectable. Despite advancements in aggressive surgery and combination chemotherapy, the prognosis of cT4b CRC remains poor. Optimizing the therapeutic sequence administered to patients with cT4b CRC to improve clinical outcomes is crucial. In the present study, patients with unresectable cT4b and nodal stage N1-2 CRC were investigated at a single institution. A total of 20 consecutive patients were treated with pre-operative concurrent chemoradiation by using 5-fluorouracil/leucovorin/oxaliplatin (FOLFOX) since February 2015 and were regularly followed up until March 2020. Due to their poor response to concurrent chemoradiation (CCRT) with FOLFOX, the chemotherapy regimen was changed to irinotecan plus 5-fluorouracil/leucovorin (FOLFIRI) as the second-line neoadjuvant treatment. Genetic alterations, such as microsatellite instability (MSI), were documented, and the expression levels of excision repair cross-complementing group 1 (ERCC1) and ERCC2 were examined. Of the 20 patients, the tumors of 14 patients (70%) became resectable after FOLFIRI administration. The median duration between the last date of radiotherapy and surgery was 32.7 weeks (range, 10.1–59.3 weeks). Of note, 4 of the 14 patients with resectable tumors (28.6%) achieved a pathologic complete response. The median overall survival and progression-free survival were 27.5 months (range, 12–39 months) and 27.5 months (range, 8–39 months), respectively. The cancerous specimens of all of the patients (100%) exhibited ERCC2 overexpression and 18 specimens (90%) had ERCC1 overexpression. Only one tumor (5%) exhibited high MSI. The present study indicated that ERCC overexpression associated with the poor response of FOLFOX-based CCRT and FOLFIRI after FOLFOX-based CCRT failure may have a potential role in conversion to resectable tumors by neoadjuvant treatment in cT4b CRC. However, a further prospective study with more patients is required to improve the precision of the conclusions.

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.

Role of common ERCC1 polymorphisms in cisplatin-resistant epithelial ovarian cancer patients: A study in Chinese cohort

Epithelial ovarian cancer (EOC) contributes the majority of death cases among various ovarian malignancies. Although a standard method of treatment is the surgical removal of malignant tissue followed by platinum-based chemotherapy, a group of patients does not respond appropriately to cisplatin. An appropriate response to cisplatin has been linked with the nucleotide excision repair mechanism. The present study aims to investigate the role of polymorphisms in DNA repair genes, excision repair cross-complementation group 1 (ERCC1) with susceptibility to EOC development and tumour response to platinum-based chemotherapy in Chinese EOC patients. Patients (n = 559) reporting to the Department of Oncology and general surgery, the First Affiliated Hospital of Kunming Medical University, were enrolled in the study. Three hundred twenty-three healthy controls hailing from similar geographical areas without a history of cancer enrolled as healthy controls. Excision repair cross-complementation group 1 polymorphisms (rs11615, rs3212986, rs735482, rs2336219, rs3212980, rs3212964, rs3212961 and rs2298881) were genotyped by appropriate methods. Distribution of genotypes and allele for ERCC1 polymorphisms (rs11615, rs3212986, rs735482, rs2336219, rs3212980, rs3212964, rs3212961 and rs2298881) were comparable among healthy controls and EOC patients. Interestingly, homozygous mutant and the minor allele for rs11615 and rs3212986 polymorphisms were significantly higher in nonresponder EOC patients when compared to those with a proper response to cisplatin treatment. The prevalence of other SNPs was comparable among the two treated clinical categories. Furthermore, combined genotype revealed significant association of rs11615: TT/ rs3212986: AA genotype combination with cisplatin nonresponder. Variants of rs11615, rs3212986 polymorphisms are associated with cisplatin resistance in Chinese EOC patients. Combined rs11615 and rs3212986 genotypes can be used as a predictive biomarker for platinum-based chemotherapy outcomes.

EGFR exon 19-deletion aberrantly regulate ERCC1 expression that may partly impaired DNA damage repair ability in non-small cell lung cancer

BACKGROUND

Epidermal growth factor receptor (EGFR) activating mutations are usually associated with DNA damage repair (DDR) deficiency. However, the precise mechanism has remained elusive. In this study, we aimed to investigate whether EGFR exon 19 deletion mutation downstream signals contributed to DDR deficiency by downregulation of excision repair cross-complementation group-1 (ERCC1), a key factor in DDR, expression and function.

METHODS

We first measured cell survival, DNA damage (γ-H2AX foci formation) and damage repair (ERCC1 and RAD51 foci formation) ability in response to DNA cross-linking drug in EGFR exon 19 deletion and EGFR wild-type cells separately. We then investigated the involvement of EGFR downstream signals in regulating ERCC1 expression and function in EGFR exon 19 deletion cells as compared with EGFR wild-type ones.

RESULTS

We observed increased γ-H2AX, but impaired ERCC1 and RAD51 nuclear foci formation in EGFR exon 19 deletion cells as compared with EGFR wild-type ones treated with DNA cross-linker. In addition, we identified that inhibition of EGFR exon 19 deletion signals increased ERCC1 expression, whereas blocked wild-type EGFR signals decreased ERCC1 expression, on both mRNA and protein levels. Furthermore, EGFR exon 19 deletion downstream signals not only inhibited ERCC1 expression but also influenced ERCC1 foci formation in response to DNA cross-linker.

CONCLUSION

Our findings indicated that the aberrant EGFR exon 19 deletion signals were not only associated with decreased expression of ERCC1 but were also involved in impaired ERCC1 recruitment in response to DNA cross-link damage, thereby providing us with more evidence for exploring the mechanism of DDR deficiency in EGFR mutant NSCLC.

Metabolic Remodelling: An Accomplice for New Therapeutic Strategies to Fight Lung Cancer

Metabolic remodelling is a hallmark of cancer, however little has been unravelled in its role in chemoresistance, which is a major hurdle to cancer control. Lung cancer is a leading cause of death by cancer, mainly due to the diagnosis at an advanced stage and to the development of resistance to therapy. Targeted therapeutic agents combined with comprehensive drugs are commonly used to treat lung cancer. However, resistance mechanisms are difficult to avoid. In this review, we will address some of those therapeutic regimens, resistance mechanisms that are eventually developed by lung cancer cells, metabolic alterations that have already been described in lung cancer and putative new therapeutic strategies, and the integration of conventional drugs and genetic and metabolic-targeted therapies. The oxidative stress is pivotal in this whole network. A better understanding of cancer cell metabolism and molecular adaptations underlying resistance mechanisms will provide clues to design new therapeutic strategies, including the combination of chemotherapeutic and targeted agents, considering metabolic intervenients. As cancer cells undergo a constant metabolic adaptive drift, therapeutic regimens must constantly adapt.

Excision repair cross-complementing group-1 (ERCC1) induction kinetics and polymorphism are markers of inferior outcome in patients with colorectal cancer treated with oxaliplatin

Background

ERCC1, a component of nucleotide excision repair pathway, is known to repair DNA breaks induced by platinum drugs. We sought to ascertain if ERCC1 expression dynamics and a single nucleotide polymorphism (SNP) rs11615 are biomarkers of sensitivity to oxaliplatin therapy in patients with colorectal cancer (CRC).

Methods

Western blot and qPCR for ERCC1 expression was performed from PBMCs isolated from patients receiving oxaliplatin-based therapy at specified timepoints. DNA was also isolated from 59 biorepository specimens for SNP analysis. Clinical benefit was determined using progression free survival (PFS) for metastatic CRC.

Results

ERCC1 was induced in PBMC in response to oxaliplatin in 13/25 patients with mCRC (52%). Median PFS with ERCC1 induction was 190d compared to 237d in non-induced patients (HR 2.35, CI 1.005-5.479; p=0.0182). ERCC1 rs11615 SNP analysis revealed that 43.3% harbored C/C, 41.2%-T/C and 15.5%-T/T genotype. Median PFS was significantly lower with C/C or T/C (211 and 196d) compared to T/T (590d; p=0.0310).

Conclusions

ERCC1 was induced in a sub-population of patients undergoing oxaliplatin treatment, which was associated with poorer outcome, suggesting this could serve as a marker of oxaliplatin response. C/C or C/T genotype in ERCC1 rs11615 locus decreased benefit from oxaliplatin.

ERCC1 Is a Predictor of Anthracycline Resistance and Taxane Sensitivity in Early Stage or Locally Advanced Breast Cancers

Genomic instability could be a beneficial predictor for anthracycline or taxane chemotherapy. We interrogated 188 DNA repair genes in the METABRIC cohort (n = 1980) to identify genes that influence overall survival (OS). We then evaluated the clinicopathological significance of ERCC1 in early stage breast cancer (BC) (mRNA expression (n = 4640) and protein level, n = 1650 (test set), and n = 252 (validation)) and in locally advanced BC (LABC) (mRNA expression, test set (n = 2340) and validation (TOP clinical trial cohort, n = 120); and protein level (n = 120)). In the multivariate model, ERCC1 was independently associated with OS in the METABRIC cohort. In ER+ tumours, low ERCC1 transcript or protein level was associated with increased distant relapse risk (DRR). In ER−tumours, low ERCC1 transcript or protein level was linked to decreased DRR, especially in patients who received anthracycline chemotherapy. In LABC patients who received neoadjuvant anthracycline, low ERCC1 transcript was associated with higher pCR (pathological complete response) and decreased DRR. However, in patients with ER−tumours who received additional neoadjuvant taxane, high ERCC1 transcript was associated with a higher pCR and decreased DRR. High ERCC1 transcript was also linked to decreased DRR in ER+ LABC that received additional neoadjuvant taxane. ERCC1 based stratification is an attractive strategy for breast cancers.

Progress of Individualized Chemotherapy for Gastric Carcinoma Under the Guidance of Genetic Testing

BACKGROUND

Gastric cancer is a major malignancy that has high incidence rates worldwide. Approximately 30% of patients with gastric cancer have progressed into advanced stages at the time of diagnosis. Chemotherapy is the standard-of-care for most advanced gastric cancer and elicits variable responses among patients. Personalized chemotherapy based on genetic information of individual patients with gastric cancer has gained increasing attention among oncologists for guiding chemotherapeutic regimens.

METHODS

This review summarizes recent progress of individualized chemotherapy in gastric cancer guided by pharmacogenomics. Variable medical research search engines, such as PubMed, Google Scholar, SpringerLink and ScienceDirect, were used to retrieve related literature. Only peerreviewed journal articles were selected for further analyses.

RESULTS AND CONCLUSION

The efficiency of chemotherapy in patients with gastric cancer is not only determined by chemotherapeutic drugs but is also directly and indirectly influenced by functionally correlative genes. Individual gene alteration or polymorphism remarkably affects patients' responses to particular chemotherapy. Most studies have focused on the influence of single-gene alteration on a selected drug, and only a few works explored the interaction between therapeutics and a panel of genes. Individualized chemotherapy regimens guided by a genetic survey of a multiple-gene panel are expected to remarkably improve the treatment efficacy in patients with advanced gastric cancer and may become the new standard for personalizing chemotherapy for gastric cancer in the near future.

UBE2C Induces Cisplatin Resistance via ZEB1/2-Dependent Upregulation of ABCG2 and ERCC1 in NSCLC Cells

Objectives

Cisplatin (DDP) is one of the most commonly used chemotherapeutic drugs for several cancers, including non-small-cell lung cancer (NSCLC). However, resistance to DDP eventually develops, limiting its further application. New therapy targets are urgently needed to reverse DDP resistance.

Methods

The mRNA expression of UBE2C, ZEB1/2, ABCG2, and ERCC1 was analyzed by reverse transcription-polymerase chain reaction. The protein levels of these molecules were analyzed by Western blotting and immunofluorescent staining. Cell proliferation was detected by CCK8 and MTT assays. Cell migration and invasion were analyzed by wound healing assay and Transwell assays. Promoter activities and gene transcription were analyzed by luciferase reporter assay.

Results

In this study, we examined the effect of UBE2C and ZEB1/2 expression levels in DDP-resistant cells of NSCLC. We confirmed that aberrant expression of UBE2C and ZEB1/2 plays a critical role in repressing the DDP sensitivity to NSCLC cells. Additionally, knockdown of UBE2C significantly sensitized resistant cells to DDP by repressing the expression of ZEB1/2. Mechanistic investigations indicated that UBE2C transcriptionally regulated ZEB1/2 by accelerating promoter activity. This study revealed that ZEB1/2 promotes the epithelial mesenchymal transition and expression of ABCG2 and ERCC1 to participate in UBE2C-mediated NSCLC DDP-resistant cell progression, metastasis, and invasion.

Conclusion

UBE2C may be a novel therapy target for NSCLC for sensitizing cells to the chemotherapeutic agent DDP.

Contribution of excision repair cross-complementing group 1 genotypes to triple negative breast cancer risk

Compared with other subgroups of breast cancer, triple negative breast cancer (TNBC) is considered to be the one with the greatest invasiveness and metastatic mobility, and the highest recurrence rate. Considering the lack of predictive markers for TNBC, we aimed to examine the contribution of excision repair cross complementing-group 1 (ERCC1) genotypes to TNBC. The rs11615 and rs3212986 of ERCC1 were investigated and evaluated for their associations with susceptibility to breast cancer, especially TNBC, in Taiwan. In this study, 1,232 breast cancer patients (104 were TNBC) and 1,232 healthy controls were recruited and their genotypes at ERCC1 rs11615 and rs3212986 were revealed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis. Our results indicated that genotypes of ERCC1 rs11615 (Ptrend = 2.2*10E-9), but not rs3212986 (Ptrend = 0.6181), were associated with breast cancer risk. In the allelic frequency distribution analysis, breast cancer patients carried the T allele of ERCC1 rs11615 a higher rate than the control subjects, further supporting the idea that ERCC1 rs11615 TT genotype is positively associated with breast cancer susceptibility. More importantly, the frequency of the ERCC1 rs11615 TT genotype was even higher among TNBC patients than among other subtypes of breast cancer patients (P = 0.0001, odds ratio = 1.73, 95% confidence interval = 1.15-2.63). The genotypes of ERCC1 rs11615 were not associated with Ki67 status. Our findings firstly show that the T allele of ERCC1 rs11615 can serve as a predictive biomarker for breast cancer and TNBC. We believe that ERCC1 could serve as a target for personalized treatment of breast cancer, especially for TNBC.

Excision repair cross-complementing group 1 (ERCC1) overexpression inhibits cell apoptosis and is associated with unfavorable prognosis of esophageal squamous cell carcinoma

Excision repair cross-complementing group 1 (ERCC1) functions as a nucleotide excision repair (NER) enzyme. Altered ERCC1 expression or function is closely associated with cancer development and progression. This study determined the association of ERCC1 expression with survivin expression, clinicopathological characteristics, and survival of esophageal squamous cell carcinoma (ESCC) patients after postoperative concurrent chemoradiotherapy.Tissue specimens from 102 resected ESCC patients were acquired for immunohistochemical analysis of ERCC1 and survivin protein expression.ERCC1 expression was detected in 62.7% of ESCC tissues and in 9.8% of normal squamous epithelium tissues (P < .01), while survivin expression was detected in 60.8% of ESCC tissues and in 19.6% of normal squamous epithelia (P < .01). ERCC1 overexpression associated with advanced tumor clinical stage and lymph node metastasis (P < .05), but not with tumor size, depth of invasion, or differentiation (P > .05). ERCC1 overexpression was also associated with survivin levels (r = 0.42, P < .01) and worse progression-free survival of ESCC patients after concurrent chemoradiotherapy. Multivariate analysis data revealed that ERCC1 and survivin protein expression were independent predictors of overall survival of ESCC patients after chemotherapy and/or radiotherapy (P < .05).ERCC1 overexpression is an important phenotype that is associated with ESCC lymph node metastasis and advanced tumor clinical stages. ERCC1 expression may also inhibit ESCC cell apoptosis via regulating survivin expression, and ERCC1 and survivin overexpression are independent predictors of prognosis for ESCC patients who receive chemotherapy and/or radiotherapy.

Relationship Between Expression of Proteins ERCC1, ERCC2, and XRCC1 and Clinical Outcomes in Patients with Rectal Cancer Treated with FOLFOX-Based Preoperative Chemoradiotherapy

BACKGROUND

Platinum resistance enhances DNA damage repair through nucleotide excision repair mechanisms involving the excision repair cross-complementing group 1 (ERCC1), X-ray cross-complementing group 1 (XRCC1), and excision repair cross-complementing group 2 (ERCC2). We evaluated the correlation between the expression of these three DNA repair genes and clinical outcomes in patients with rectal cancer receiving FOLFOX-based preoperative chemoradiotherapy (CRT).

METHODS

Using immunohistochemistry, we examined the expression of ERCC1, ERCC2, and XRCC1 in pre-CRT cancer tissues from 86 patients with rectal cancer who had undergone curative resection and preoperative CRT with FOLFOX-4 to identify potential predictors of clinical outcomes.

RESULTS

Following CRT, 57 and 29 patients were classified as responders (pathological tumor regression grade TRG 0 and TRG 1) and poor responders (TRG 2 and TRG 3), respectively. The multivariate analysis revealed that ERCC1 overexpression was correlated with a poor CRT response [p < 0.0001; odds ratio (OR), 9.397; 95% confidence interval (CI) 2.721-32.457]. Furthermore, a poor response to CRT (pathological TRG of 2-3) (p = 0.18; OR 5.685; 95% CI 1.349-23.954) and abnormal pre-CRT serum carcinoembryonic antigen levels (>5 ng/mL) (p = 0.03; OR 6.288; 95% CI 1.198-33.006) were independent predictors of postoperative relapse. By contrast, ERCC2 and XRCC1 expression did not play predictive roles in the analyzed patients.

CONCLUSIONS

ERCC1 overexpression is associated with a poor preoperative CRT response in patients with rectal cancer receiving FOLFOX-based preoperative CRT. ERCC1 is a potential biomarker for identifying patients who can benefit from customized treatment programs.

Identification of small molecule inhibitors of ERCC1-XPF that inhibit DNA repair and potentiate cisplatin efficacy in cancer cells

ERCC1-XPF heterodimer is a 5′-3′ structure-specific endonuclease which is essential in multiple DNA repair pathways in mammalian cells. ERCC1-XPF (ERCC1-ERCC4) repairs cisplatin-DNA intrastrand adducts and interstrand crosslinks and its specific inhibition has been shown to enhance cisplatin cytotoxicity in cancer cells. In this study, we describe a high throughput screen (HTS) used to identify small molecules that inhibit the endonuclease activity of ERCC1-XPF. Primary screens identified two compounds that inhibit ERCC1-XPF activity in the nanomolar range. These compounds were validated in secondary screens against two other non-related endonucleases to ensure specificity. Results from these screens were validated using an in vitro gel-based nuclease assay. Electrophoretic mobility shift assays (EMSAs) further show that these compounds do not inhibit the binding of purified ERCC1-XPF to DNA. Next, in lung cancer cells these compounds potentiated cisplatin cytotoxicity and inhibited DNA repair. Structure activity relationship (SAR) studies identified related compounds for one of the original Hits, which also potentiated cisplatin cytotoxicity in cancer cells. Excitingly, dosing with NSC16168 compound potentiated cisplatin antitumor activity in a lung cancer xenograft model. Further development of ERCC1-XPF DNA repair inhibitors is expected to sensitize cancer cells to DNA damage-based chemotherapy.

Expression of ERCC1 and TUBB3 in Locally Advanced Cervical Squamous Cell Cancer and its Correlation with Different Therapeutic Regimens

Background

Several studies in solid tumors have shown that expression of excision repair cross-complementation group 1 (ERCC1) and class III β-tubulin (TUBB3) can predict response to chemoradiotherapy and might be prognostic factors. We assessed the role of ERCC1 and TUBB3 expressions as predictive and prognostic factors in locally advanced cervical squamous cell carcinoma (LACSCC) patients treated with different neoadjuvant regimens.

Methods

ERCC1 and TUBB3 were detected in 88 patients with LACSCC by immunohistochemical analysis. Sixty-two patients were included in 3 different prospective trials and grouped as follows: vinorelbine or docetaxel (group A, n = 44) and ifosfamide-vinorelbine-cisplatin (group B, n = 18). Both groups were compared with standard cisplatin chemoradiotherapy (group C, n = 26). Clinical data at baseline, disease-free survival (DFS) and overall survival (OS) were also collected. Univariate and multivariate Cox models were used to analyze the risk factors.

Results

Thirty-five patients (39.8%) and 18 (20.5%) had high ERCC1 and TUBB3 expression, respectively. Both proteins were overexpressed in tumors with unfavorable characteristics. High ERCC1 was associated with advanced FIGO stage (p = 0.034) and progressive disease (49% vs. 28%). Poor DFS (p = 0.021) and OS (p = 0.005) were observed in group C patients with high ERCC1 expression. Multivariate analysis showed that ERCC1 expression, FIGO stage and pretreatment hemoglobin level were significant prognostic factors (p = 0.002, p = 0.008 and p = 0.005, respectively).

Conclusions

ERCC1 expression could be a predictive and prognostic factor in LACSCC patients who receive cisplatin monotherapy. Conversely, TUBB3 had no impact on survival in patients treated with antimicrotubule agents.

ERCC1 expression status predicts the response and survival of patients with metastatic or recurrent cervical cancer treated via platinum-based chemotherapy

The deoxyribonucleic acid (DNA) repair gene encoding the excision-repair cross-complementation group 1 (ERCC1) protein is known to predict the response to platinum-based chemotherapy. Our aim was to explore whether ERCC1 expression predicted tumor response and survival in patients with recurrent or metastatic cervical cancer treated via platinum-based chemotherapy. We analyzed 32 such patients. ERCC1 expression was assessed immunohistochemically in pretreatment biopsy samples. Of the 32 patients, 13 (40.6%) were ERCC1 high. ERCC1-low patients exhibited a significantly higher response rate (73.7%) than did others (15.4%). The median progression-free survival differed significantly by ERCC1 status, being 135 days in ERCC1-high and 242 days in ERCC1-low patients (hazard ratio, 2.428; 95% confidence interval, 1.145-5.148, P = .032). Overall survival was significantly longer in ERCC1-low (617 days) than in ERCC1-high (320 days) patients (hazard ratio, 2.322; 95% confidence interval, 1.051-5.29; P = .037). Thus, pretreatment ERCC1 expression status can be used to predict tumor response and survival of patients with recurrent or metastatic uterine cervical cancer receiving platinum-based chemotherapy.

Phase II Trial of Target-guided Personalized Chemotherapy in First-line Metastatic Colorectal Cancer

PURPOSE

The aim of this study was to investigate the feasibility and efficacy of personalizing treatment of patients with advanced untreated colorectal cancer (CRC).

PATIENTS AND METHODS

Patients with untreated metastatic CRC, performance status 0-1, and candidates for systemic chemotherapy were eligible. Tumor tissues were analyzed for KRAS, BRAF, and PI3K mutations and expression of topoisomerase-1 (Topo-1), excision repair cross-complementing gene 1 (ERCC1), thymidylate synthase (TS), and thymidine phosphorylase (TP). Patients with Topo-1 expression received irinotecan, whereas patients with negative Topo-1 and ERCC1 expression received oxaliplatin. Otherwise, patients received physician's choice of treatment. If TS was positive, no fluoropyrimidine was administered and if negative, 5-flurorouracil if TP was negative, or capecitabine if TP was positive. KRAS-mutated patients were treated with bevacizumab, whereas KRAS-native received cetuximab. The primary endpoint of the study was progression-free survival (PFS).

RESULTS

A total of 74 patients were enrolled and 67 received personalized treatment including irinotecan (n=27), oxaliplatin (n=16), FOLFIRI (n=12), and FOLFOX (n=12). Thirty-eight patients received cetuximab and 29 bevacizumab. With a median follow-up time of 18.3 months (95% confidence interval [CI], 4-36), the overall median PFS was 8.3 months (95% CI, 6.9-9.7), representing a 12-month PFS rate of 36.5% (95% CI, 25-48). Overall clinical benefit, including response rate and disease stabilization, was 86% (95% CI, 73%-97%). The overall median survival was 21 months (95% CI, 11-40).

CONCLUSIONS

Real-time target-guided personalized first-line treatment of patients with advanced CRC is feasible but, with the approached used, did not result in a clear improvement in PFS to warrant phase III testing.

Association between the ERCC1 polymorphism and platinum-based chemotherapy effectiveness in ovarian cancer: a meta-analysis

Background

Ovarian cancer is a prominent public health problem which affects people all around the world. Platinum-based chemotherapy is a common treatment for ovarian cancer, however, the effectiveness of chemotherapy varies from patient to patient. The excision repair cross complementation group 1 (ERCC1) protein may mediate chemotherapy resistance. A meta-analysis was conducted to explore whether platinum-based chemotherapy effectiveness could be attributed to the ERCC1 C19007T polymorphisms.

Methods

Seven major databases (EMBASE, Web of Science, Pubmed, Springer Link, Chinese National Knowledge Infrastructure (CNKI), EBSCO and Science Direct databases) were searched for eligible studies. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the results.

Results

In this meta-analysis, 1169 subjects (425 non-responders and 744 responders) from 8 studies were included. The overall OR (C vs. T alleles) using random model was 1.07 (95% CI 0.75-1.52, P = 0.7), which was not statistically significant. Moreover, there was no significant difference in the analysis by race.

Conclusion

There is no association between the ERCC1 C19007T polymorphism and platinum-based chemotherapy effectiveness in ovarian cancer. The polymorphism did not have a significant impact on platinum-based chemotherapy in non-responders and responders.

Prognostic implication of ERCC1 protein expression in resected oropharynx and oral cavity cancer

BACKGROUND

Excision repair cross complement group 1 (ERCC1) expression is a predictive biomarker for platinum-containing treatment in squamous cell carcinoma of head and neck (SCCHN). However, the prognostic significance after surgical resection is not well understood.

METHODS

Oropharynx (n=143) or oral cavity (n=61) SCCHN patients undergoing surgery were included. ERCC1 protein expression and HPV status were assessed by ERCC1 and p16 immunohistochemistry.

RESULTS

The ERCC1, over-expressed in 66.7% of patients, was associated with oral cavity cancer (P<0.001), well differentiation (P=0.036), and HPV negativity (P<0.001). In TCGA database, ERCC1 mRNA upregulation was enriched in HPV-negative and oral cavity cancers, and associated with HRAS mutation (P<0.001). The prognostic role of ERCC1 was not different according to HPV status. High ERCC1 expression showed a trend toward poor prognosis in patients with an advanced stage (P=0.079) with marginal significance.

CONCLUSIONS

The ERCC1 expression was not prognostic in surgically resected oropharynx/oral cavity SCCHN, irrespective of HPV status. However, it could provide additional prognostic information for advanced stage patients.

Biological and predictive role of ERCC1 polymorphisms in cancer

Excision repair cross-complementation group 1 (ERCC1) is a key component in DNA repair mechanisms and may influence the tumor DNA-targeting effect of the chemotherapeutic agent oxaliplatin. Germline ERCC1 polymorphisms may alter the protein expression and published data on their predictive and prognostic value have so far been contradictory. In the present article we review available evidence on the clinical role and utility of ERCC1 polymorphisms and, in the absence of a 'perfect' trial, what we call the 'sliding doors' trial, we present the data of ERCC1 genotyping in our local patient population. We found a useful predictive value for oxaliplatin-induced risk of anemia.

Investigating the Frequency of the ERCC1 Gene C8092A Polymorphism in Iranian Patients with Advanced Gastric Cancer Receiving Platinum-based Chemotherapy

BACKGROUND

Platinum compounds are the main drugs for treatment of advanced gastric cancer. Previous studies have shown that clinical outcome with platinum-based compounds depends on ERCC1 polymorphisms. The aim of this study was to investigate the frequency of a common polymorphism of ERCC1 gene (C8092A) in Iranian patients with advanced gastric cancer receiving platinum chemotherapy.

MATERIALS AND METHODS

Genetic analysis of the ERCC1 C8092A polymorphism was performed by the PCR - RFLP method using 50 paraffin-embedded tissue specimens.

RESULTS

Of the 50 cases, 32% of individuals showed CC genotype, 24% of them had CA genotype and 44% of patients had AA genotype.

CONCLUSIONS

Based on the results, using of platinum-based chemotherapy would be expected to be specifically beneficial in only 32% of patients.

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

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

Combination gemcitabine/cisplatin therapy and ERCC1 expression for resected pancreatic adenocarcinoma: Results of a Phase II prospective trial

BACKGROUND

Standard adjuvant treatment for pancreatic adenocarcinoma (PDAC) is gemcitabine [Gem(CONKO-001: Gem vs. placebo DFS:13.4 vs. 6.7 mo; P < 0.001; OS:22.8 vs. 20.2 mo; P = 0.01)]. Addition of cisplatin (Cis) to Gem has resulted in increased PFS for advanced and metastatic disease, which may be predicted by low expression of excision repair cross-complementing group-1 (ERCC1), the key enzyme in nucleotide excision repair. This Phase II prospective trial assesses outcomes of patients treated with adjuvant Gem/Cis, stratifying results by tumor ERCC1 expression.

METHODS

Patients with resected PDAC were enrolled (2010-2013) and received Gem(1,000 mg/m(2) )/Cis(50 mg/m(2) ). Tumor ERCC1 expression was evaluated by immunohistochemistry and dichotomized into low or high expression. Primary outcomes were recurrence-free and overall survival (RFS/OS).

RESULTS

Of 22 pts, 16(73%) were Stage IIB, 5(23%) Stage IIA, and 1(4%) Stage IA. Grade 3/4 toxicity occurred in 13 pts (59%); neutropenia was most common (n = 9;41%). Median follow-up was 37.5 months. Median RFS was 16.7 mo; OS was 35.5 mo. Low ERCC1 (n = 15;75%) compared to high ERCC1 (n = 5;25%) was not associated with improved RFS (12.4 vs. 16.7 mo; P = 0.68) or OS (Median not reached vs. 21.6 mo; P = 0.22).

CONCLUSIONS

Adjuvant Gem/Cis is feasible in patients with resected pancreatic adenocarcinoma. RFS and OS for Gem/Cis appear promising compared to historic control. Tumor ERCC1 expression can be reliably evaluated, and low expression is present in most patients. J. Surg. Oncol. 2016;114:336-341. © 2016 Wiley Periodicals, Inc.

High ERCC1 expression is associated with platinum-resistance, but not survival in patients with epithelial ovarian cancer

The present study aimed to investigate the association between excision repair cross-complementation group 1 (ERCC1) expression and clinical resistance to platinum-based chemotherapy or clinical characteristics, including survival time, in patients with epithelial ovarian cancer (EOC). ERCC1 expression was determined by immunohistochemical staining in 92 tumor specimens from patients with EOC. The effect of ERCC1 expression on progression-free survival time (PFS) or overall survival time (OS), and its association with clinical resistance to platinum-based chemotherapy was investigated by Kaplan-Meier survival analysis, Cox regression analysis and the χ² test. Of 92 patients with EOC, 89.13% (82/92) had ERCC1-positive tumors. The positive rate was significantly higher in platinum-resistant patients compared with those who were platinum-responding (P<0.05). The PFS and median OS were 12 and 30 months, respectively, in ERCC1 high expression patients, and 17 and 39 months, respectively, in ERCC1 low expression patients. However, there was no statistically significant difference in PFS (P=0.099) or OS (P=0.103) between the high and low expression groups. Furthermore, it was identified that ERCC1 was not an independent factor affecting the prognosis of patients with EOC based on Cox proportional hazards regression analysis. These results demonstrate that high ERCC1 expression is associated with resistance to platinum-based chemotherapy, but not with survival time, and ERCC1 protein expression is not an independent factor or the only factor affecting the prognosis of patients with EOC.

ERCC1 expression affects outcome in metastatic pancreatic carcinoma treated with FOLFIRINOX: A single institution analysis

INTRODUCTION

No clinically useful predictive factor has been yet identified for treatment of metastatic pancreatic cancer (mPC). It is noteworthy that FOLFIRINOX, despite its high toxicity, is effective only in some patients. We retrospectively analyzed expression of excision repair cross-complementing group-1 (ERCC1) - involved in the repair of platinum induced damage - in patients affected by mPC treated with FOLFIRINOX in order to evaluate its predictive role.

RESULTS

FOLFIRINOX resulted more effective in patients with normal ERCC1 levels than in those with ERCC1 hyper-expression. Median progression free survival (PFS) was 11 vs. 4 months (HR 0.26; 95% CI 0.14-0.50; p<.0001), median overall survival (OS) 16 vs. 8 months (HR 0.23; 95% CI 0.12-0.46; p<.0001) and disease control rate (DCR) 93% vs. 50% (p=0.00006). The advantage was confirmed at univariate and multivariate analysis.

PATIENTS AND METHODS

71 patients with histologically proven mPC and treated with FOLFIRINOX as first-line therapy were considered eligible. mRNA ERCC1 expression was determined using RT-PCR analysis.

DISCUSSION

ERCC1 might be an effective predictor of response to FOLFIRINOX in mPC. Patients overexpressing ERCC1 should be excluded by this often toxic therapy and referred to an alternative treatment.

Pharmacogenomics: Biomarker-Directed Therapy for Bladder Cancer

The clinical management of bladder cancer has seen little change over the last three decades and there is pressing need to identify more effective treatments for advanced disease. Low clinical use of neoadjuvant therapies stems from historical limitations in the ability to predict patients most likely to respond to combination chemotherapies. This article focuses on recent molecular and genetic studies, highlighting promising clinical trials and retrospective studies, and discusses emerging trials that use predictive biomarkers to match patients with therapies to which they are most likely to respond. The implementation of predictive genomic and molecular biomarkers will revolutionize urologic oncology and the clinical management of bladder cancer.

CITED2 silencing sensitizes cancer cells to cisplatin by inhibiting p53 trans-activation and chromatin relaxation on the ERCC1 DNA repair gene

In this study, we show that silencing of CITED2 using small-hairpin RNA (shCITED2) induced DNA damage and reduction of ERCC1 gene expression in HEK293, HeLa and H1299 cells, even in the absence of cisplatin. In contrast, ectopic expression of ERCC1 significantly reduced intrinsic and induced DNA damage levels, and rescued the effects of CITED2 silencing on cell viability. The effects of CITED2 silencing on DNA repair and cell death were associated with p53 activity. Furthermore, CITED2 silencing caused severe elimination of the p300 protein and markers of relaxed chromatin (acetylated H3 and H4, i.e. H3K9Ac and H3K14Ac) in HEK293 cells. Chromatin immunoprecipitation assays further revealed that DNA damage induced binding of p53 along with H3K9Ac or H3K14Ac at the ERCC1 promoter, an effect which was almost entirely abrogated by silencing of CITED2 or p300. Moreover, lentivirus-based CITED2 silencing sensitized HeLa cell line-derived tumor xenografts to cisplatin in immune-deficient mice. These results demonstrate that CITED2/p300 can be recruited by p53 at the promoter of the repair gene ERCC1 in response to cisplatin-induced DNA damage. The CITED2/p300/p53/ERCC1 pathway is thus involved in the cell response to cisplatin and represents a potential target for cancer therapy.

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

OBJECTIVES

The purpose of this study was to characterize the intratumoral expression profiles of excision repair cross-complementing gene 1 (ERCC1), dihydropyrimidine dehydrogenase (DPD), and human equilibrative nucleotide transporter 1 (hENT1) in ampullary carcinomas (ACs) to evaluate their prognostic values and better tailor adjuvant chemotherapy for individual patients with AC after surgery.

METHODS

This study included 49 patients with AC who underwent a curative pancreaticoduodenectomy. Various clinicopathological factors, including ERCC1, DPD, and hENT1, were analyzed in relation to postoperative disease recurrence and the patients' survival.

RESULTS

The median recurrence-free survival and overall survival were 24.5 months and 32.4 months, respectively. Multivariate Cox regression analysis of recurrence-free survival identified a DPD expression (hazard ratio [HR], 8.18; 95% confidence interval [CI], 2.00-34.8; P = 0.003) and combined ERCC1/DPD expression (HR, 134.8; 95% CI, 11.8-1920; P < 0.001) as independent predictors of disease recurrence. Multivariate Cox regression analysis of overall survival also identified a DPD expression (HR, 8.48; 95% CI, 1.71-46.3; P = 0.008) and combined ERCC1/ DPD expression (HR, 135.6; 95% CI, 11.8-1940; P < 0.001) as independent predictors of survival.

CONCLUSIONS

The DPD and ERCC1 expression profile could potentially serve as a useful prognostic biomarker and therapeutic target for surgically resected patients with AC.

ERCC1 as a Predictive Marker for FOLFOX Chemotherapy in an Adjuvant Setting

Purpose

The purpose of this study was to identify the excision repair cross-complementation group 1 (ERCC1) as a predictive marker for FOLFOX adjuvant chemotherapy in stages II and III colon cancer patients.

Methods

A total of 166 high risk stages II and III colon cancer patients were retrospectively enrolled in this study, and data were collected prospectively. They underwent a curative resection followed by FOLFOX4 adjuvant chemotherapy. We analyzed ERCC1 expression in the primary colon tumor by using immunohistochemical staining. The oncological outcomes included the 5-year disease-free survival (DFS) rate. The DFS was analyzed by using the Kaplan-Meier method with the log-rank test. A Cox proportional hazard model was used for the prognostic analysis.

Results

ERCC1-positive expression was statistically significant in the older patients (P = 0.032). In the multivariate analysis, the prognostic factors for DFS were female sex (P = 0.016), N stage (P = 0.009), and postoperative carcinoembryonic antigen level (P = 0.001), but ERCC1 expression was not a statistically significant prognostic factor for DFS in the univariate analysis (P = 0.397). The 5-year DFS rate was not significantly associated with the ERCC1 expression in all patients (P = 0.396) or with stage III disease (P = 0.582).

Conclusion

We found that ERCC1 expression was not significantly correlated with the 5-year DFS as reflected by the oncologic outcomes in patients with high-risk stages II and III colon cancer treated with FOLFOX adjuvant chemotherapy.

Clinical utility of plasma Epstein-Barr virus DNA and ERCC1 single nucleotide polymorphism in nasopharyngeal carcinoma

BACKGROUND

Single nucleotide polymorphism (SNP) of the excision repair cross-complementing group 1 (ERCC1) gene has been linked with sensitivity to platinum and radiation. The authors hypothesized that the ERCC1 genotype for the SNPs cytosine-to-thymine substitution at codon 118 (C118T) and cytosine-to-adenine substitution at codon 8092 (C8092A) is prognostic in patients with nasopharyngeal carcinoma (NPC) who receive either radiotherapy (RT) or cisplatin plus RT.

METHODS

The authors tested their hypothesis using biomarker screening samples from the Hong Kong NPC Study Group 0502 trial, which was a prospective, multicenter clinical trial that used post-RT plasma Epstein-Bar virus (EBV) DNA (pEBV) levels to screen patients with high-risk NPC for adjuvant chemotherapy.

RESULTS

ERCC1 SNPs were analyzed in 576 consecutive patients who were screened by pEBV. In the total biomarker population, there was no significant association of ERCC1 C118T or C8092A genotype with relapse-free survival (RFS) or overall survival (OS). There also was no correlation between ERCC1 genotype and ERCC1 protein or messenger RNA expression in a subset of patients who had available paired biopsies. Post-RT pEBV status was the only independent prognosticator for RFS and OS in multivariate analyses. However, there was a significant interaction between ERCC1 C118T genotype and post-RT pEBV status (RFS, P = .0106; OS, P = .0067). The ERCC1 C118T genotype was significantly associated with both RFS (hazard ratio, 1.67; 95% confidence interval, 1.07-2.61; P = .024) and OS (hazard ratio, 2.31; 95% confidence interval, 1.22-4.40; P = .0106) in the post-RT pEBV-negative population, but not in the pEBV-positive population.

CONCLUSIONS

The current results prospectively validate pEBV as the most significant prognostic biomarker in NPC that can be used to select high-risk patients for adjuvant therapy. The ERCC1 C118T genotype may help to identify a favorable subgroup (approximately 7%) of pEBV-negative patients with NPC who have an excellent prognosis and can be spared the toxicities of further therapy.

DNA Repair Endonucleases: Physiological Roles and Potential as Drug Targets

Genomic DNA is constantly exposed to endogenous and exogenous damaging agents. To overcome these damaging effects and maintain genomic stability, cells have robust coping mechanisms in place, including repair of the damaged DNA. There are a number of DNA repair pathways available to cells dependent on the type of damage induced. The removal of damaged DNA is essential to allow successful repair. Removal of DNA strands is achieved by nucleases. Exonucleases are those that progressively cut from DNA ends, and endonucleases make single incisions within strands of DNA. This review focuses on the group of endonucleases involved in DNA repair pathways, their mechanistic functions, roles in cancer development, and how targeting these enzymes is proving to be an exciting new strategy for personalized therapy in cancer.

Protein expression of DNA damage repair proteins dictates response to topoisomerase and PARP inhibitors in triple-negative breast cancer

Patients with metastatic triple-negative breast cancer (TNBC) have a poor prognosis. New approaches for the treatment of TNBC are needed to improve patient survival. The concept of synthetic lethality, brought about by inactivating complementary DNA repair pathways, has been proposed as a promising therapeutic option for these tumors. The TNBC tumor type has been associated with BRCA mutations, and inhibitors of Poly (ADP-ribose) polymerase (PARP), a family of proteins that facilitates DNA repair, have been shown to effectively kill BRCA defective tumors by preventing cells from repairing DNA damage, leading to a loss of cell viability and clonogenic survival. Here we present preclinical efficacy results of combining the PARP inhibitor, ABT-888, with CPT-11, a topoisomerase I inhibitor. CPT-11 binds to topoisomerase I at the replication fork, creating a bulky adduct that is recognized as damaged DNA. When DNA damage was stimulated with CPT-11, protein expression of the nucleotide excision repair enzyme ERCC1 inversely correlated with cell viability, but not clonogenic survival. However, 4 out of the 6 TNBC cells were synergistically responsive by cell viability and 5 out of the 6 TNBC cells were synergistically responsive by clonogenic survival to the combination of ABT-888 and CPT-11. In vivo, the BRCA mutant cell line MX-1 treated with CPT-11 alone demonstrated significant decreased tumor growth; this decrease was enhanced further with the addition of ABT-888. Decrease in tumor growth correlated with an increase in double strand DNA breaks as measured by γ-H2AX phosphorylation. In summary, inhibiting two arms of the DNA repair pathway simultaneously in TNBC cell lines, independent of BRCA mutation status, resulted in un-repairable DNA damage and subsequent cell death.

Excision repair cross complementation group 1 is a chemotherapy-tolerating gene in cisplatin-based treatment for non-small cell lung cancer

This study aimed to evaluate the biological functions of excision repair cross complementation goup 1 (ERCC1) in cell proliferation, cell cycle, invasion and cisplatin response of non-small cell lung cancer (NSCLC) cells. Firstly, ERCC1 gene was successfully transfected into H1299 cells by gene cloning and transfection techniques. Then, cell proliferation was determined with the cell growth curve and colony-forming assays. Flow cytometry (FCM) was employed to investigate the cell cycle distribution. The ability of cell invasion was estimated by means of Matrigel invasion assays. Response of NSCLC cells to cisplatin was detected utilizing MTT assays, and the intracellular drug concentrations were determined by the high performance liquid chromatography (HPLC) analysis. Expression of the two cell membrane proteins, P-glycoprotein (P-gp) and multidrug resistance-associated protein (MRP), was also evaluated utilizing FCM technique. By contrast, ERCC1 expression in the NSCLC A549 cells was silenced by small interfering RNA (siRNA) through RNAi technique. In addition, the cytotoxic effect of cisplatin on A549 cells was detected by MTT assays. In the present study, the results demonstrated that ERCC1 had no effect on cell proliferation, cell cycle and the ability of invasion, but showed significant impact on cisplatin response of the NSCLC H1299 cells. Furthermore, siRNA-induced suppression of ERCC1 evidently enhanced sensitivity to cisplatin of NSCLC A549 cells. Therefore, it is confirmed that ERCC1 is a chemotherapy-tolerating gene and a promising predictor in tailoring chemotherapy of NSCLC.