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

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

Genomic alterations and abnormal expression of APE2 in multiple cancers.

Although APE2 plays essential roles in base excision repair and ATR-Chk1 DNA damage response (DDR) pathways, it remains unknown how the APE2 gene is altered in the human genome and whether APE2 is differentially expressed in cancer patients. Here, we report multiple-cancer analyses of APE2 genomic alterations and mRNA expression from cancer patients using available data from The Cancer Genome Atlas (TCGA). We observe that APE2 genomic alterations occur at ~17% frequency in 14 cancer types (n = 21,769). Most frequent somatic mutations of APE2 appear in uterus (2.89%) and skin (2.47%) tumor samples. Furthermore, APE2 expression is upregulated in tumor tissue compared with matched non-malignant tissue across 5 cancer types including kidney, breast, lung, liver, and uterine cancers, but not in prostate cancer. We also examine the mRNA expression of 13 other DNA repair and DDR genes from matched samples for 6 cancer types. We show that APE2 mRNA expression is positively correlated with PCNA, APE1, XRCC1, PARP1, Chk1, and Chk2 across these 6 tumor tissue types; however, groupings of other DNA repair and DDR genes are correlated with APE2 with different patterns in different cancer types. Taken together, this study demonstrates alterations and abnormal expression of APE2 from multiple cancers.

Chemoradiotherapy response prediction model by proteomic expressional profiling in patients with locally advanced cervical cancer.

OBJECTIVE: Resistance to chemo-radiation therapy is a substantial obstacle that compromises treatment of advanced cervical cancer. The objective of this study was to investigate if a proteomic panel associated with radioresistance could predict survival of patients with locally advanced cervical cancer. METHODS: A total of 181 frozen tissue samples were prospectively obtained from patients with locally advanced cervical cancer before chemoradiation. Expression levels of 22 total and phosphorylated proteins were evaluated using well-based reverse phase protein arrays. Selected proteins were validated with western blotting analysis and immunohistochemistry. Performances of models were internally and externally validated. RESULTS: Unsupervised clustering stratified patients into three major groups with different overall survival (OS, P = 0.001) and progression-free survival (PFS, P = 0.003) based on detection of BCL2, HER2, CD133, CAIX, and ERCC1. Reverse-phase protein array results significantly correlated with western blotting results (R2 = 0.856). The C-index of model was higher than clinical model in the prediction of OS (C-index: 0.86 and 0.62, respectively) and PFS (C-index: 0.82 and 0.64, respectively). The Kaplan-Meier survival curve showed a dose-dependent prognostic significance of risk score for PFS and OS. Multivariable Cox proportional hazard model confirmed that the risk score was an independent predictor of PFS (HR: 1.6; 95% CI: 1.4-1.9; P < 0.001) and OS (HR: 2.1; 95% CI: 1.7-2.5; P < 0.001). CONCLUSION: A proteomic panel of BCL2, HER2, CD133, CAIX, and ERCC1 independently predicted survival in locally advanced cervical cancer patients. This prediction model can help identify chemoradiation responsive tumors and improve prediction for clinical outcome of cervical cancer patients.

Bacterial expression, purification, and initial characterization of a full-length Cas13b protein from Porphyromonas gingivalis.

The CRISPR-Cas13b system is a recently identified Class 2, RNA-targeting CRISPR-Cas system. The system has been repurposed to achieve robust mRNA knockdown and precise RNA-editing in mammalian cells. While the CRISPR-Cas13b system has become a powerful tool for nucleic acids manipulation, the mechanisms of the system are still not fully understood. Cas13b endonucleases from different bacterial species show poor overall sequence homologies, suggesting that structural (and probably functional) diversities may exist. It is therefore important to study CRISPR-Cas13b cases from different bacterial species. Here we report the expression, purification, and initial characterization of a Cas13b endonuclease that is associated with the 8th putative CRISPR locus from Porphyromonas gingivalis genome (Pgi8Cas13b). The full-length Pgi8Cas13b protein (1119 residues) was successfully expressed in E. Coli cells, and purified by affinity and ion-exchange chromatography methods. The purified protein is biologically active, being able to bind its cognate crRNA with high specificity and affinity. Preparation of biologically active Pgi8Cas13b protein provides the basis for further in vitro biochemical and biophysical studies of the Pgi8Cas13b CRISPR system.

ERCC1 expression in advanced colorectal cancer and matched liver metastases.

BACKGROUND: Platinum-based chemotherapy is part of the standard treatment for patients with colorectal cancer. ERCC1 is a potential predictive biomarker for platinum-based chemotherapy. The aim of this study was to examine interobserver agreement on ERCC1 protein expression in primary colorectal cancer as well as corresponding liver metastasis. Furthermore, comparison of ERCC1-expression in primary tumor and the corresponding liver metastasis was performed. METHODS: Forty patients with primary colorectal cancers and corresponding liver metastases were included. One slide was stained with the anti-ERCC1 antibody, 4F9 clone (DAKO) and evaluated by two gastrointestinal pathology consultants and a pathology registrar separately. Interobserver agreement was evaluated for primary tumors and liver metastases using kappa (κ) statistics. Discordant scorings were reviewed, and consensus was obtained. The expression in primary tumor was compared with the corresponding liver metastases. RESULTS: For the primary tumors agreement was found in 85% of the tumors corresponding to an unweighted kappa value of 0,79 (95% CI 0,64-0,94). For the liver metastases agreement was found in 76% corresponding to an unweighted kappa value of 0,64 (95% CI 0,49-0,79). When comparing primary tumors to the corresponding metastases, no concordance in ERCC1-expression was observed. CONCLUSION: Interobserver agreement of ERCC1 expression was good for both primary tumors and liver metastases, which is crucial for a potential predictive biomarker. As no concordance between primary tumor and liver metastases was found it seems to be of high importance to use tissue from actual tumor burden for evaluation of ERCC1 expression. Further studies and correlation to clinical outcome are warranted.

Predictive Value of ERCC1, ERCC2, and XRCC Expression for Patients with Locally Advanced or Metastatic Gastric Cancer Treated with Neoadjuvant mFOLFOX-4 Chemotherapy.

The dismal outcome in patients with locally advanced or metastatic gastric cancer (GC) highlights the need for effective systemic neoadjuvant chemotherapy to improve clinical results. This study evaluated the correlation between the expression of three DNA repair genes, namely the excision repair cross-complementing group 1 (ERCC1), excision repair cross-complementing group 2 (ERCC2), and X-ray repair cross-complementing protein 1 (XRCC1) and the clinical outcome of patients with locally advanced or metastatic GC treated with mFOLFOX-4 neoadjuvant chemotherapy. Fifty-eight patients with histologically confirmed locally advanced or metastatic GC following neoadjuvant mFOLFOX-4 chemotherapy were enrolled between January 2009 and January 2018. We analyzed clinicopathological features and ERCC1, ERCC2, and XRCC1 expression to identify potential predictors of clinical response. Among the 58 patients, 16 (27.6%) were categorized into the response group (partial response) and 42 into the nonresponse group (stable disease in 24 patients and progressive disease in 18 patients). A multivariate analysis showed that ERCC1 overexpression (P = 0.003), ERCC2 overexpression (P = 0.049), and either ERCC1 or ERCC2 overexpression (P = 0.002) were independent predictors of response following mFOLFOX-4 neoadjuvant chemotherapy. Additionally, ERCC1 and ERCC2 overexpression did not only predict the response but also progression-free survival (both P < 0.05) and overall survival (both P < 0.05). ERCC1 and ERCC2 overexpression are promising predictive biomarkers for patients with locally advanced or metastatic GC receiving neoadjuvant mFOLFOX-4 chemotherapy and the potential clinical implication is mandatory for further investigation.

Randomized, Phase II Study Prospectively Evaluating Treatment of Metastatic Esophageal, Gastric, or Gastroesophageal Cancer by Gene Expression of ERCC1: SWOG S1201.

PURPOSE: Platinum-based therapy is the standard of care in patients who have HER2-negative, advanced esophagogastric cancer (AEGC). Retrospective data suggest that intratumoral ERCC1 levels may determine platinum sensitivity. A randomized, phase II study was performed in patients with AEGC to explore whether the efficacy of a platinum-based therapy with fluorouracil, leucovorin, and oxaliplatin (FOLFOX) versus a non-platinum-containing regimen of irinotecan and docetaxel (IT) differed according to ERCC1 levels. PATIENTS AND METHODS: Overall, 202 untreated patients with HER2-negative AEGC and a Zubrod performance status of 0-1 were evaluated prospectively for mRNA expression of ERCC1 level and then randomly assigned to FOLFOX or IT, stratified by the intratumoral statuses of ERCC1 low (< 1.7) or high (≥ 1.7). Objectives were to assess progression-free survival (PFS) and overall survival (OS) in all patients treated with FOLFOX compared with IT, stratified by low and high ERCC1 levels, and to assess for interactive effects between ERCC1 expression and treatment arm. RESULTS: Eighty-six percent of patients had ERCC1 values < 1.7. Thus, evaluation of the ERCC1-high subgroup was limited. Grade ≥ 3 anemia, dehydration, diarrhea, and fatigue were greater in patients with IT. Occurrences of grade ≥ 3 neuropathy and decreased neutrophils were greater in patients with FOLFOX. In all patients, FOLFOX had a statistically superior median PFS compared with IT (5.7 v 2.9 months; hazard ratio, 0.68; P = .02). In patients with ERCC1 levels < 1.7 receiving FOLFOX, PFS and response rate were statistically superior to IT, with no significant difference in OS. CONCLUSION: The evaluation of ERCC1 in patients with upper GI tumors was thwarted by an overwhelming predominance of low ERCC1 mRNA expression. Nonetheless, distribution of treatment effects on PFS did not vary with expression. For all patients and for those with low ERCC1 expression, FOLFOX was superior in efficacy to IT.

FSH1 overexpression triggers apoptosis in Saccharomyces cerevisiae.

FSH1 belongs to the family of serine hydrolases in yeast and is homologous to the human ovarian tumor suppressor gene (OVAC2). Our preliminary results showed that cells lacking Fsh1p exhibit an increase in cell growth, and a decrease in the expression of AIF1 and NUC1 (apoptosis responsive genes) when compared to the wild type cells. Growth inhibition of cells overexpressing FSH1 is due to induction of cell death associated with cell death markers typical of mammalian apoptosis namely DNA fragmentation, phosphatidylserine externalization, ROS accumulation, Cytochrome c release, and altered mitochondrial membrane potential. When wild type cells were overexpressed with FSH1 there was up regulation of AIF1 level when compared to control cells suggesting that overexpression of FSH1 regulated cell death in yeast.

ERCC1-XPF deficiency is a predictor of olaparib induced synthetic lethality and platinum sensitivity in epithelial ovarian cancers.

PURPOSE: PARP inhibitor maintenance therapy in platinum sensitive sporadic ovarian cancers improves progression free survival. However, biomarker for synthetic lethality in platinum sensitive sporadic disease is yet to be defined. ERCC1-XPF heterodimer is a key player in nucleotide excision repair (NER) involved in the repair of platinum induced DNA damage. In the current study, we tested whether ERCC1-XPF deficiency would predict synthetic lethality to the PARP inhibitor Olaparib and platinum sensitivity in ovarian cancers. METHODS: ERCC1, XPF and PARP1 protein expression was evaluated in tumors from a cohort of 331 patients treated at Nottingham University Hospitals and correlated to clinicopathological features and survival. Pre-clinically, ERCC1 and XPF was depleted in A2780 (platinum sensitive) and A2780cis (platinum resistant) ovarian cancer cell lines and tested for platinum sensitivity as well as for Olaparib induced synthetic lethality. RESULTS: Low ERCC1 was significantly associated with improved progression free survival (PFS) in patients with ovarian cancers in univariate (p = 0.001) and multivariate (p = 0.002) analysis. In addition, low ERCC1/low XPF (p = 0.003) or low ERCC1/low PARP1 (p = 0.0001) tumors was also linked to better PFS compared to high ERCC1/high XPF or high ERCC1/high PARP1 tumors. Pre-clinically, ERCC1 or XPF depletion not only increased platinum sensitivity but also increased toxicity to Olaparib therapy. Increased sensitivity was associated with DNA double strand breaks (DSBs) accumulation, cell cycle arrest and increased apoptosis. CONCLUSION: The data provide evidence that low ERCC1 is not only a predictor of platinum sensitivity but is also a promising biomarker for Olaparib induced synthetic lethality in ovarian cancers.

Expression levels of TUBB3, ERCC1 and P-gp in ovarian cancer tissues and adjacent normal tissues and their clinical significance.

PURPOSE: To investigate the expressions of class III ß-tubulin (TUBB3), nucleotide excision repair cross-complementary gene 1 (ERCC1) and P-glycoprotein (P-gp) in ovarian cancer tissues and adjacent normal tissues and their clinical significance. METHODS: Ovarian cancer patients undergoing surgical resection at the Department of Oncology of the Affiliated Hospital of Shandong Medical College from March 2012 to May 2016 were enrolled in this study, from which 166 cases of pathologically confirmed cancer tissues and 50 cases of adjacent normal tissues were collected. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the messenger RNA (mRNA) expression levels of TUBB3, ERCC1 and P-gp in ovarian cancer tissues and adjacent normal tissues, and their relationships with ovarian cancer clinical stage and grade of pathological differentiation were analyzed. RESULTS: The expression levels of TUBB3, ERCC1 and P-gp in ovarian cancer tissues were significantly higher than those in adjacent normal tissues (p<0.05). The later the clinical stage of ovarian cancer was, the higher the expression levels of TUBB3, ERCC1 and P-gp were (p<0.05). The lower the pathological differentiation grade of ovarian cancer was, the higher the expression levels of TUBB3, ERCC1 and P-gp were (p<0.05). TUBB3, ERCC1 and P-gb were positively correlated with clinical stage and pathological differentiation grade. CONCLUSION: TUBB3, ERCC1 and P-gp are involved in the occurrence and development of ovarian cancer and can be used as important indexes judging the severity of ovarian cancer, providing a reference for the occurrence and development of the disease in ovarian cancer patients in clinical practice.

Nucleotide excision repair protein ERCC1 and tumour-infiltrating lymphocytes are potential biomarkers of neoadjuvant platinum resistance in high grade serous ovarian cancer.

OBJECTIVE: ERCC1 is a nucleotide excision repair protein that may have a role in drug resistance in high grade serous ovarian cancer (HGSOC). We hypothesized that ERCC1 expression and tumour infiltrating lymphocytes (TILS) are induced by chemotherapy in HGSOC, which may be prognostically useful. METHODS: 115 HGSOC patients were used for this study. 92 (80%) of the tissue analysed had not been exposed to platinum chemotherapy. The remaining 20% (n = 23) of cases received combination or monotherapy with carboplatin before tissue was collected. Immunohistochemistry was used to score for ERCC1 expression and morphology to score for TILs. Correlation analysis of all clinical parameters, TILs and ERCC1 and Kaplan-Meier survival analysis was performed using the ERCC1 and TILs scoring parameters (0, 1, 2 or 3). RESULTS: ERCC1 expression was 2-fold higher in the neoadjuvant chemotherapy group compared to the primary cytoreductive surgery group (p < 0.0001). The mean overall survival for the neoadjuvant group with high ERCC1 was 141.6 ±â€¯20.2 months which was significantly longer than absent ERCC1 survival of 61 + 22.6 months (p = 0.028). ERCC1 score strongly correlated with TILs score across the whole cohort (0.349, p = 1.3 × 10-4) suggesting there is a relationship between ERCC1 expression and TILs, but this requires further investigation. CONCLUSION: In conclusion, ERCC1 was identified as a potential biomarker of platinum response overall survival in HGSOC undergoing neoadjuvant HGSOC treatment.

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.

Association of DNA Repair and Drug Transporter in Relation to Chemosensitivity in Primary Culture of Thai Gastric Cancer Patients.

Acquired resistance is a major reason for poor clinical outcomes in cancer chemotherapy patients. The aim of this study was to determine the sensitivity to anticancer drugs and to identify the alterations of DNA repair and drug transporter in a model of primary culture obtained from pre- and post-platinum-based anticancer treatments in nine Thai gastric cancer patients. Ex vivo sensitivity to anti-cancer drugs (cisplatin, oxaliplatin, 5-fluorouracil (5-FU) and irinotecan) was analysed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The expression of the drug transporter (multidrug resistance-associated protein 1 (MRP1), P-glycoprotein (P-gp)) and DNA repair (X-ray cross-complementing gene 1 (XRCC1) and excision repair cross-complementing 1 (ERCC1)) were examined by RT-PCR. The IC50 to cisplatin and oxaliplatin of the cells obtained from gastric cancer patients after clinical drug treatments were administered to five patients (55.5%) revealed a significant increase when compared with prior treatments. The basal expression values of XRCC1, ERCC1 and MRP1 obtained from the treated patients were in correlation with those of IC50. Ex vivo platinum drug treatment of the primary culture obtained from naïve patients over seven days also revealed a significant increase in MRP1 (7/9), XRCC1 (4/9) and ERCC1 (4/9). These observations have also been observed in the KATOIII cell line. Clinical treatment by platinum-based anti-cancer drug can develop acquired drug resistance in Thai gastric cancer patients through upregulation in the expression of drug transporter MRP1 and DNA repair XRCC1 and ERCC1. In cell culture model, cisplatin-resistant gastric cancer cell line KATOIII/diamminedichloroplatinum (KATOIII/DDP) significantly increased the expression level of these genes when compared to its parental cells (KATOIII).

Predictive value of excision repair cross- complementation group 1 expression in locoregionally advanced nasopharyngeal carcinoma receiving cisplatin-based concurrent chemoradiotherapy.

BACKGROUND: Cisplatin-based concurrent chemoradiotherapy is recommended for nasopharyngeal carcinoma (NPC) at advanced stages. Excision repair cross-complementation group 1 (ERCC1) plays an important function in the repair of DNA damage that is a critical process of chemo- and radiotherapy. OBJECTIVE: This study aimed to investigate the clinical significance of ERCC1 expression in NPC treated with cisplatin-based concurrent chemoradiotherapy in locoregionally advanced NPC. METHODS: The expression level of ERCC1 and its association with clinicopathological characteristics in 205 locoregionally advanced NPC patients receiving cisplatin-based concurrent chemoradiotherapy were analyzed retrospectively. RESULTS: The correlation analysis revealed that the treatment-sensitive patients displayed dramatically lower ERCC1 expression than treatment-resistant cases did. Furthermore, the Kaplan-Meier plots revealed lower ERCC1 expression was significantly associated with better survival. Multivariate analysis further showed that the ERCC1 expression was an independent predictor of NPC patients' survival. CONCLUSIONS: ERCC1 expression might be a useful predictive marker in patients with locoregionally advanced NPC receiving cisplatin-based concurrent chemoradiotherapy.

Effects of indirubin and isatin on cell viability, mutagenicity, genotoxicity and BAX/ERCC1 gene expression.

CONTEXT: Indigofera suffruticosa Miller (Fabaceae) and I. truxillensis Kunth produce compounds, such as isatin (ISA) and indirubin (IRN), which possess antitumour properties. Their effects in mammalian cells are still not very well understood. OBJECTIVE: We evaluated the activities of ISA and/or IRN on cell viability and apoptosis in vitro, their genotoxic potentials in vitro and in vivo, and the IRN- and ISA-induced expression of ERCC1 or BAX genes. MATERIALS AND METHODS: HeLa and/or CHO-K1 cell lines were tested (3 or 24 h) in the MTT, Trypan blue exclusion, acridine orange/ethidium bromide, cytokinesis-blocked micronucleus (CBMN) and comet (36, 24 and 72 h) tests after treatment with IRN (0.1 to 200 µM) or ISA (0.5 to 50 µM). Gene expression was measured by RT-qPCR in HeLa cells. Swiss albino mice received IRN (3, 4 or 24 h) by gavage (50, 100 and 150 mg/kg determined from the LD50 - 1 g/kg b.w.) and submitted to comet assay in vivo. RESULTS: IRN reduced the viability of CHO-K1 (24 h; 5 to 200 µM) and HeLa cells (10 to 200 µM), and was antiproliferative in the CBMN test (CHO-K1: 0.5 to 10 µM; HeLa: 5 and 10 µM). The drug did not induce apoptosis, micronucleus neither altered gene expression. IRN and ISA were genotoxic for HeLa cells (3 and 24 h) at all doses tested. IRN (100 and 150 mg/kg) also induced genotoxicity in vivo (4 h). CONCLUSION: IRN and ISA have properties that make them candidates as chemotherapeutics for further pharmacological investigations.

Generation and characterization of a human iPSC cell line expressing inducible Cas9 in the "safe harbor" AAVS1 locus.

We report the generation-characterization of a fetal liver (FL) B-cell progenitor (BCP)-derived human induced pluripotent stem cell (hiPSC) line CRISPR/Cas9-edited to carry/express a single copy of doxycycline-inducible Cas9 gene in the "safe locus" AAVS1 (iCas9-FL-BCP-hiPSC). Gene-edited iPSCs remained pluripotent after CRISPR/Cas9 genome-edition. Correct genomic integration of a unique copy of Cas9 was confirmed by PCR and Southern blot. Cas9 was robustly and specifically expressed on doxycycline exposure. T7-endonuclease assay demonstrated that iCas9 induces robust gene-edition when gRNAs against hematopoietic transcription factors were tested. This iCas9-FL-BCP-hiPSC will facilitate gene-editing approaches for studies on developmental biology, drug screening and disease modeling.

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.

ERCC1-expressing circulating tumor cells as a potential diagnostic tool for monitoring response to platinum-based chemotherapy and for predicting post-therapeutic outcome of ovarian cancer.

BACKGROUND: We recently showed that the presence of ERCC1+CTCs is an independent predictive biomarker for platinum-resistance and poor prognosis of ovarian cancer. The goal of our current research was to determine how the auxiliary assessment of ERCC1-transcripts influences overall CTC-detection rate. We extended this investigation from an initially predictive setting to paired pre- and post-therapeutic blood analysis in order to see, whether ERCC1+CTCs dynamics mirror response to chemotherapy. METHODS: 65 Paired blood samples (10ml) of primary ovarian cancer patients at primary diagnosis and after chemotherapy were studied for CTCs with the AdnaTest Ovarian Cancer (QIAGEN Hannover GmbH). We analyzed the tumor-associated transcripts EpCAM, MUC-1 and CA-125. ERCC1-transcripts were investigated in a separate approach by singleplex RT-PCR. RESULTS: Auxiliary assessment of ERCC1-transcripts enhanced the overall CTC-detection rate up to 17%. ERCC1+CTCs (defined as positive for one of the AdnaTest markers plus ERCC1-positivity) were detected in 15% of patients at primary diagnosis and in 12% after chemotherapy. The presence of ERCC1+CTCs after chemotherapy correlated with platinum-resistance (P=0.01), reduced PFS (P=0.0293) and OS (P=0.0008) and their persistence indicated poor post-therapeutic outcome (PFS: P=0.005; OS: P=0.0058). Interestingly, the assessment of ERCC1-transcripts alone was sufficient for the detection of prognostic relevant ERCC1-expressing CTCs. CONCLUSION: Auxiliary assessment of ERCC1-transcripts expands the phenotypic spectrum of CTC detection and defines an additional overlapping fraction of ERCC1-expressing CTCs, which are potentially selected by platinum-based chemotherapy. Specifically, we suggest that ERCC1+CTCs could additionally be useful as a surrogate for monitoring platinum-based chemotherapy and to assess the post-therapeutic outcome of ovarian cancer.

Chemosensitizing effect of shRNA-mediated ERCC1 silencing on a Xuanwei lung adenocarcinoma cell line and its clinical significance.

Lung cancer is a common fatal malignancy in both men and women. Xuanwei, Yunnan has the highest incidence of lung cancer in China. The area has a specific risk factor in the domestic combustion of bituminous coal, and lung cancer patients from this area tend to be resistant to platinum-based treatments. However, little is known about the mechanism of platinum resistance in patients from Xuanwei. Herein, we used lentiviral infection with shRNA to silence expression of the DNA repair enzyme ERCC1 in XWLC05 both in its RNA and protein expression level, a lung adenoma cell line derived from a patient from Xuanwei. ERCC1 expression in this cell line is high and contributes to its resistance to cisplatin. Suppression of ERCC1 decreased XWLC05 proliferation in vitro (IC50 of cisplatin 1.34 µM for shRNA-infected cells vs. 4.54 µM for control cells) and increased the apoptotic rate after treatment with cisplatin (81.2% shRNA cells vs. 58% control cells, P<0.05). Progression-free survival was longer in ERCC1-negative lung adenoma patients than those with high ERCC1 levels (30 vs. 11 months, P<0.0001). ERCC1 expression was identified as a prognostic marker for overall survival in the patient cohort with operable lesions. Taken together, our data identify ERCC1 as a disease marker in lung adenoma patients from Xuanwei and confirm the significance of resection for the subsequent effect of platinum treatment in these patients. Additional studies are needed to determine the mechanism of ERCC1-induced platinum resistance in lung adenoma patients from Xuanwei.

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

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