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

Prognostic significance of ERCC1 expression in postoperative patients with gastric cancer

AIM

This study explored the correlation between the expression of excision repair cross-complementation group 1 (ERCC1) and the prognosis of gastric cancer patients.

METHODS

From January 2005 to December 2008, 605 patients who underwent radical surgery in The First Affiliated Hospital of Nanjing Medical University were enrolled. We conducted the follow-up every 6 months and its contents included a comprehensive medical history, tumor markers and abdominal ultrasound or CT and other imaging findings. Deadline was April 30, 2013 and follow-up time between 51 to 91 months. Survival time is calculated from the date of diagnosis to death or last follow-up date. Immunohistochemistry (IHC) was used to assess the expression of ERCC1 in resected samples. The relationship between ERCC1 expression and survival of patients was investigated. The comparison of count data were analyzed by Chi-square test. Median survival time (MST) and the 5-year survival rate were calculated by life table analysis. The Kaplan-Meier curves were used for survival analysis.

RESULTS

ERCC1 expression was positive in 412 patients (68.1%). There is no significant difference between ERCC1-positive group and ERCC1-negative group in terms of the MST and 5-year survival rate (P=0.455). The MST and 5-year survival rate have no significant difference (P=0.162) between group with chemotherapy and group with no chemotherapy in patients with ERCC1-positive expression. However, the MST and 5-year survival rate in patients with ERCC1-negative expression benefited more from with chemotherapy (P=0.019). The ERCC1-positive patients survived longer than those ERCC1-negative patients (P=0.183) in subgroup with no adjuvant chemotherapy. In the subgroup analysis, ERCC1 expression had no significant relationship with overall survival in patients with stage II or III gastric cancer (P>0.05).

CONCLUSIONS

ERCC1 might be a good prognostic factor for the patients of gastric cancer after radical resection. Patients with ERCC1-negative expression could benefit more from adjuvant chemotherapy.

ERCC1 expression and tumor regression predict survival in esophageal squamous cell carcinoma patients receiving combined trimodality therapy

PURPOSE

Combined trimodality therapy with neoadjuvant chemoradiation followed by surgery has shown promising results for locally advanced operable esophageal cancer. DNA repair proteins may affect treatment efficacy through repairing DNA damage induced by chemotherapy and radiation therapy. We evaluated the associations of XRCC1, ERCC1 and MGMT expression with histopathologic response and survival in patients with locally advanced operable esophageal squamous cell carcinoma (ESCC) who received neoadjuvant chemoradiation.

METHODS

Paraffin-embedded pre-treatment tissue samples, collected by endoscopic biopsy from patients treated with cisplatin-based neoadjuvant chemoradiation followed by surgery, were immunohistochemically stained for XRCC1, ERCC1 and MGMT expression.

RESULTS

Of the 44 patients, major histopathologic response was noted in 26 (59.1%) patients. 68.8% of patients with ERCC1-negative tumors had major histopathologic response, compared to 53.6% of those who expressed positive ERCC1, though the difference was not statistically significant (P=0.361). The patients with ERCC1-negative tumor presented much better overall survival than those positive for ERCC1 expression (P=0.018). Patients with major histopathologic response had a 3-year survival rate of 96.2% versus those with minor response, with a 3-year survival rate of 41.5% (P=0.000). Multivariate analysis showed that ERCC1 expression and histopathologic response were independent predictive factors of overall survival in patients with locally advanced operable ESCC receiving neoadjuvant chemoradiation.

CONCLUSION

Patients with ERCC1-negative tumors show a benefit from neoadjuvant chemoradiation, ERCC1 expression and tumor regression are useful predictive markers in patients with locally advanced operable ESCC receiving neoadjuvant chemoradiation followed by surgery.

Genetic polymorphisms in XPG could predict clinical outcome of platinum-based chemotherapy for advanced non-small cell lung cancer

We conducted a prospective study to investigate the role of four single nucleotide polymorphisms (SNPs) of XPG on the clinical outcome of advanced non-small cell lung cancer (NSCLC) treated with platinum-based doublets chemotherapy. In total, 277 patients with histologically confirmed NSCLC were mainly from December 2007 and December 2008. The genotypes of rs2296147T>C, rs1047768C>T, rs873601G>A, and rs17655G>C were determined by polymerase chain reaction-restriction fragment length polymorphism. By univariate analysis, a shorter survival was associated with older age, sex, and higher disease stage. By multivariate Cox regression analysis, patients carrying rs2296147 TT genotype and T allele were prognostic factors of progression-free survival (PFS) and overall survival (OS). Similarly, patients carrying rs873601 GG genotype and G allele were marginally significantly associated with favorable outcome for PFS and OS. We found that individuals carrying both rs2296147 T allele and rs873601 G allele were associated with better PFS and OS. However, rs1047768C>T and rs17655G>C polymorphisms did not influence the PFS and OS of advanced NSCLC. In summary, our study provided statistical evidence that XPG rs2296147T>C and rs873601G>A polymorphisms may be used as surrogate markers toward individualizing NSCLC treatment strategies.

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

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

Expression of DNA-repair proteins and their significance in pancreatic cancer and non-cancerous pancreatic tissues of Sprague-Dawley rats

Background

To establish a model of pancreatic cancer induced by 7,12-dimethylbenzantracene (DMBA) in Sprague–Dawley (SD) rats, and detect the expression of DNA-repair proteins (MGMT, ERCC₁, hMSH₂, and hMLH₁) and their significance in pancreatic cancer and non-cancerous pancreatic tissues of SD rats.

Methods

DMBA was directly implanted into the parenchyma of rat pancreas (group A and group B), and group B rats were then treated with trichostatin A (TSA). The rats in both groups were executed within 3 to 5 months, and their pancreatic tissues were observed by macrography and under microscopy. Meanwhile, the rats in the control group (group C) were executed at 5 months. Immunohistochemistry was used to assay the expression of MGMT, ERCC₁, hMSH₂, and hMLH₁.

Results

The incidence of pancreatic cancer in group A within 3 to 5 months was 48.7% (18/37), including 1 case of fibrosarcoma. The incidence of pancreatic cancer in group B was 33.3% (12/36), including 1 case of fibrosarcoma. The mean of maximal diameters of tumors in group A was higher than that in group B (P <0.05). No pathological changes were found in pancreas of group C and other main organs (except pancreas) of group A and group B. No statistical differences were found among the positive rates of MGMT, ERCC₁, hMSH₂, and hMLH₁ in ductal adenocarcinoma and non-cancerous pancreatic tissues of group A (P >0.05). The positive rates of MGMT, ERCC₁, hMSH₂, and hMLH₁ were significantly lower in ductal adenocarcinoma than those in non-cancerous tissues of group B (P ≤0.05). All pancreas of group C had positive expression of MGMT, ERCC₁, hMSH₂, and hMLH₁ and two cases of fibrosarcoma showed a negative expression.

Conclusions

DMBA, directly implanted into the parenchyma of pancreas, creates an ideal pancreatic cancer model within a short time. TSA might restrain DNA damage related to the genesis and growth of pancreatic cancer in rats. The DNA-repair proteins, including MGMT, ERCC₁, hMSH₂, and hMLH₁, might play an important role in the genesis of pancreatic cancer induced by DMBA in rats.

Predicting the outcome of platinum-based chemotherapies in epithelial ovarian cancer using the 8092C/A polymorphism of ERCC1: a meta-analysis

BACKGROUND

In the present study, we performed this meta-analysis to estimate the association between excision repair cross-complementation group 1 (ERCC1) gene polymorphism and clinical resistance to platinum-based chemotherapy in the patients with epithelial ovarian cancer (EOC).

METHODS

A total of 10 studies consist of 1479 EOC patients relating ERCC1 rs11615C/T and rs3212986C/A polymorphisms to the response of platinum-based chemotherapy were included in this meta-analysis.

RESULTS

The analysis showed that the AA genotype of the rs3212986C/A polymorphism in ERCC1 was associated with progression-free survival of EOC patients (HR = 1.39, 95% CI = 1.12-1.73) and that the CA or AA genotypes could influence overall survival (HR = 1.28, 95% CI = 1.05-1.56; and HR = 1.55, 95% CI = 1.17∼2.05, respectively).

CONCLUSIONS

The ERCC1 rs3212986C/A polymorphism may be a useful prognostic marker in platinum-based treatment of EOC.

Pharmacogenomics in bladder cancer

Bladder cancer is a common cancer worldwide. For patients presenting with muscle-invasive disease, the 5-year survival rate is approximately 50%. Cisplatin-based combination chemotherapy is recommended in the neoadjuvant setting before cystectomy and is also the first line in the metastatic setting. However, the survival benefit of such therapy is modest. The identification of pharmacogenomic biomarkers would enable the rational and personalized treatment of patients by selecting those patients that would benefit most from such therapies sparing others the unnecessary toxicity. Conventional therapies would be recommended for an expected responder, whereas a nonresponder would be considered for alternative therapies selected on the basis of the individual's molecular profile. Although few effective bladder cancer therapies have been introduced in the past 30 years, several targeted therapies against the molecular drivers of bladder cancer appear promising. This review summarizes pharmacogenomic biomarkers that require further investigation or prospective evaluation or both, and publicly available tools for drug discovery and biomarker identification from in vitro data.

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

背景与目的

残存肿瘤是影响射频消融（radiofrequency ablation, RFA）治疗肺恶性肿瘤效果的重要因素，联合铂类药物化疗是减少残存肿瘤的重要手段之一。核苷酸切除修复交叉互补基因1（excision repair cross-complementation group 1, ERCC1）的表达水平是影响铂类药物化疗效果的重要因素之一。RFA治疗后残存肿瘤会发生一些生物学特性变化，但有关ERCC1表达变化的研究尚无报道。本研究旨在探讨RFA治疗后兔肺内残存VX2鳞癌细胞ERCC1表达水平的变化。

方法

应用组织块悬液注射法建立兔VX2鳞癌肺内移植瘤模型。58只荷瘤新西兰白兔随机分为对照组（n=10）和RFA组（n=48）。在RFA治疗时，通过控制电极展开范围、输出功率、治疗时间的方法，造成肿瘤残存。应用免疫组织化学方法检测残存肿瘤细胞在不同时间点ERCC1表达的阳性率。

结果

RFA组残存肿瘤组织ERCC1表达阳性率在1 d-5 d呈一过性升高（53.7%±1.6% & 32.9%±2.5%），5 d后恢复至对照组水平。

结论

因在RFA治疗后1 d-5 d内残存肿瘤细胞ERCC1表达增高，在此期间给予铂类药物化疗可能效果不佳。

Predictive value of ERCC1, ERCC2, and XRCC1 overexpression for stage III colorectal cancer patients receiving FOLFOX-4 adjuvant chemotherapy

OBJECTIVES

To determine the correlation between expression of three DNA repair genes and early failure/clinical outcome of stage III colorectal cancer (CRC) patients administrated with FOLFOX-4, including the excision repair cross-complementation group 1 (ERCC1), the excision repair cross-complementing 2 (ERCC2), and X-ray repair cross-complementing protein 1 (XRCC1).

MATERIALS AND METHODS

We retrospectively analyzed clinicopathological features and ERCC1, ERCC2, XRCC1 expressions by immunohistochemical staining in 180 stage III CRC patients undergoing curative resection and treated with FOLFOX-4 chemotherapy to identify predictors of postoperative early failure.

RESULTS

Among 180 CRC patients, 44 patients were classified into early failure group, and 136 patients were categorized into non-early failure group. A multivariate logistic regression analysis showed that ERCC1 overexpression (P = 0.005), and high postoperative carcinoembryonic antigen (CEA) levels (P = 0.001) were independent predictors of early failure. Additionally, ERCC1 overexpression was not only a predictor of early failure but also for disease-free survival (P < 0.001) and overall survival (P < 0.001). However, no predictive roles of ERCC2 and XRCC1 expression among these analyzed patients.

CONCLUSIONS

ERCC1 overexpression is an important predictor of early failure in patients with stage III CRC administrating FOLFOX-4 adjuvant chemotherapy and this marker may help identify patients who would benefit from intensive follow-up and enhance therapeutic programs.

Induction of apoptosis and suppression of ERCC1 expression by the potent amonafide analogue 8-c in human colorectal carcinoma cells

Previous studies have reported that 8-c [6-(2-(2-(dimethylamino)ethylamino)ethylamino)-2-octyl-1H-benzo[de]isoquinoline-1,3(2H)-dione], a novel amonafide analogue, was generated as a new anticancer candidate. However, little is known about its activity in chemoresistant cells. In this study, the antitumor effects of 8-c on the multi-drug-resistant human colorectal carcinoma cancer cell lines HCT-116/L-OHP and HCT-8/VCR have been investigated for the first time. 8-c showed similar concentration-dependent inhibitory activities against multi-drug-resistant cells and corresponding parental cell lines by the MTT assay after 48 h of treatment. 8-c treatment resulted in the induction of apoptosis, as evidenced by fluorescent staining analysis, comet assay data, and the increase in the number of apoptotic cells as detected by flow cytometry. Western blot, qPCR, and siRNA techniques were used to elucidate the molecular mechanism. Our study suggested that the apoptotic effect of 8-c can be attributed to the upregulation of p53, caspase-3, and cleaved poly(ADP-ribose) polymerase (PARP) and the downregulation of Bcl-2. Furthermore, ERCC1 is essential for nucleotide excision repair. ERCC1 expression was correlated with sensitivity to chemotherapy in various colon cancer cell lines. It is intriguing that decreases in ERCC1 protein and mRNA levels were also observed in the HCT-116/L-OHP and HCT-8/VCR cells after exposure to 8-c. Further transient transfection of multi-drug-resistant cells with ERCC1 siRNA enhanced 8-c-induced cytotoxicity. In contrast, epidermal growth factor-induced increase in ERCC1 protein levels was shown to rescue cell viability upon 8-c treatment. These findings suggest that 8-c has a strong potential to be developed as a new antitumor agent for the treatment of multi-drug-resistant colon cancer cells, and is worthy of further studies.

Triple negative breast cancers have a reduced expression of DNA repair genes

DNA repair is a key determinant in the cellular response to therapy and tumor repair status could play an important role in tailoring patient therapy. Our goal was to evaluate the mRNA of 13 genes involved in different DNA repair pathways (base excision, nucleotide excision, homologous recombination, and Fanconi anemia) in paraffin embedded samples of triple negative breast cancer (TNBC) compared to luminal A breast cancer (LABC). Most of the genes involved in nucleotide excision repair and Fanconi Anemia pathways, and CHK1 gene were significantly less expressed in TNBC than in LABC. PARP1 levels were higher in TNBC than in LABC. In univariate analysis high level of FANCA correlated with an increased overall survival and event free survival in TNBC; however multivariate analyses using Cox regression did not confirm FANCA as independent prognostic factor. These data support the evidence that TNBCs compared to LABCs harbour DNA repair defects.

MyD88 in DNA repair and cancer cell resistance to genotoxic drugs

BACKGROUND

MyD88 is an adaptor molecule in Toll-like receptor and interleukin 1 receptor signaling implicated in tumorigenesis through proinflammatory mechanisms. We have recently reported that MyD88 also directly promotes optimal activation of the Ras/Erk pathway. Here we investigate MyD88 implication in the maintenance of the transformation of Ras-dependent tumors.

METHODS

RNA interference was used to inhibit MyD88 expression in the colon cancer cell lines HCT116 and LS513. Apoptosis, DNA damage, p53 function, ERCC1 levels, and Ras and inflammatory signaling pathways were analyzed. Using in vitro assays and xenotransplantation in nude mice (five per group), HCT116 tumor growth was assessed following MyD88 knockdown in presence or absence of chemotherapy.

RESULTS

MyD88 exerts antiapoptotic functions in colon cancer cells via the Ras/Erk, but not the NF-κB, pathway. MyD88 inhibition leads to defective ERCC1-dependent DNA repair and to accumulation of DNA damage, resulting in cancer cell death via p53. Furthermore, we show that knocking down MyD88 sensitizes cancer cells to genotoxic agents such as platinum salts in vitro and in vivo. Indeed, HCT116 tumor growth following treatment with a combination of suboptimal MyD88 inhibition and suboptimal doses of cisplatin (fold tumor increase = 5.4 ± 1.6) was statistically significantly reduced in comparison to treatment with doxycycline alone (12.4 ± 3.1) or with cisplatin alone (12.5 ± 2.6) (P = .005 for both, one-sided Student t test).

CONCLUSIONS

Collectively, these results indicate a novel and original link between inflammation, DNA repair, and cancer, and provide further rationale for MyD88 as a potential therapeutic target in Ras-dependent cancers, in the context of concomitant genotoxic chemotherapy.

Differential expression and prognostic value of ERCC1 and thymidylate synthase in resected gastric adenocarcinoma

BACKGROUND

Excision repair cross-complementing gene-1 (ERCC1) and thymidylate synthase (TS) are key regulatory enzymes whose expression patterns are associated with overall survival (OS) in several malignancies. Their expression patterns and prognostic value in resected gastric adenocarcinoma (GAC) are not known.

METHODS

In total, 109 patients who underwent resection for GAC between January 2000 and June 2011 had tissue available for analysis. The primary objective was to assess for the differential expression of ERCC1 and TS using immunohistochemistry. The secondary objective was to assess for the association between OS and the expression of ERCC1 and TS.

RESULTS

The median follow-up was 21.2 months, and the median OS was 28.8 months. Resected GAC exhibited differential expression of ERCC1 (high expression, 23%; n = 25) and TS (high expression, 43%; n = 47). ERCC1 and TS expression were not associated with OS. In a subset analysis of patients who received chemotherapy (n = 73), high ERCC1 expression was associated with decreased OS (16.7 months vs 53.8 months; P = 0.03). After controlling for known adverse pathologic features, high ERCC1 expression persisted as a negative prognostic factor in multivariate Cox regression analysis (hazard ratio, 2.5; 95% confidence interval, 1.03-6.0; P = .04). Conversely, in patients who underwent resection only (n = 35), high ERCC1 expression demonstrated a trend toward improved OS (40.4 months vs 12.7 months; P = .10); a positive prognostic influence also was present on multivariate analysis (hazard ratio, 0.20; 95% confidence interval, 0.04-0.86; P = .03).

CONCLUSIONS

Resected GAC exhibited differential expression of TS and ERCC1. Among all patients, ERCC1 and TS expression levels were not associated with OS. High ERCC1 tumor expression was associated with decreased OS in the patients who received chemotherapy but was associated with increased OS in those who underwent surgery alone. ERCC1 expression had prognostic value in resected gastric cancer, and further investigation is warranted.

ERCC1 Can Be a Prognostic Factor in Hilar Cholangiocarcinoma and Extrahepatic Bile Duct Cancer, But Not in Intrahepatic Cholangiocarcinoma

PURPOSE

There are three types of bile duct cancer, intrahepatic cholangiocarcinoma (ICC), hilar cholangiocarcinoma (HC), and extrahepatic cholangiocarcinoma (EHC). Despite different clinical presentation, the same protocol has been used in treatment of patients with these cancers. We analyzed clinicopathologic findings and protein expression in order to investigate the difference and the specific prognostic factors among these three types of cancers.

MATERIALS AND METHODS

We conducted a retrospective review of 104 patients diagnosed with bile duct cancer at Seoul St. Mary's Hospital between January 1994 and May 2004. We performed immunohistochemical staining for p53, cyclin D1, thymidine phosphorylase, survivin, and excision repair cross-complementing group 1 (ERCC1).

RESULTS

Of the 104 patients, EHC was most common (44.2%). In pathologic findings, perineural invasion was significantly less common in ICC. Overall survival was similar among the three types of cancer. Lymph node invasion, lymphatic, and venous invasion showed a significant association with survival outcome in ICC, however, the differentiation of histologic grade had prognostic significance in HC and EHC. No difference in protein expression was observed among these types of cancer, however, ERCC1 showed a significant association with survival outcome in HC and EHC, not in ICC.

CONCLUSION

Based on our data, ICC showed different characteristics and prognostic factors, separate from the other two types of bile duct cancer. Conduct of further studies with a large sample size is required in order to confirm these data.

Metformin induces cytotoxicity by down-regulating thymidine phosphorylase and excision repair cross-complementation 1 expression in non-small cell lung cancer cells

Metformin is an antidiabetic drug recently shown to inhibit cancer cell proliferation and growth, although the involved molecular mechanisms have not been elucidated. In many cancer cells, high expression of thymidine phosphorylase (TP) and Excision repair cross-complementation 1 (ERCC1) is associated with poor prognosis. We used A549 and H1975 human non-small cell lung cancer (NSCLC) cell lines to investigate the role of TP and ERCC1 expression in metformin-induced cytotoxicity. Metformin treatment decreased cellular TP and ERCC1 protein and mRNA levels by down-regulating phosphorylated MEK1/2-ERK1/2 protein levels in a dose- and time-dependent manner. The enforced expression of the constitutively active MEK1 (MEK1-CA) vectors significantly restored cellular TP and ERCC1 protein levels and cell viability. Specific inhibition of TP and ERCC1 expression by siRNA enhanced the metformin-induced cytotoxicity and growth inhibition. Arachidin-1, an antioxidant stilbenoid, further decreased TP and ERCC1 expression and augmented metformin's cytotoxic effect, which was abrogated in lung cancer cells transfected with MEK1/2-CA expression vector. In conclusion, metformin induces cytotoxicity by down-regulating TP and ERCC1 expression in NSCLC cells.

ERCC1, defective mismatch repair status as predictive biomarkers of survival for stage III colon cancer patients receiving oxaliplatin-based adjuvant chemotherapy

Background:

Excision repair cross-complementation group 1 (ERCC1) expression status has been identified as a candidate marker for predicting efficacy of oxaliplatin (OX) treatment for metastatic colorectal cancer (CRC) in several trials. Also, an association between expression of mismatch repair (MMR) genes and favourable postoperative survival in stage II CRC receiving 5-FU chemotherapy has been identified. It is unknown if the expression of ERCC1 protein and MMR status are associated with survival of stage III colon cancer receiving OX-based chemotherapy.

Methods:

Immunohistochemistry (IHC) analysis of the expression of MMR and ERCC1 was performed on tumour tissue of 255 patients with stage III colon cancer. In all, 95 patients received fluoropyrimidine-based chemotherapy and 160 patients received OX-based chemotherapy. A predictive model for 5-year disease-free survival (DFS) and overall survival (OS) was constructed using Kaplan–Meier analysis, logistic and Cox regression.

Results:

Patients who were treated with OX-based therapy with positive ERCC1 tumours had lower 5-year DFS (54%) and OS (60%) than those with negative ERCC1 tumours (72% and 78%, respectively; DFS HR: 1.98, 95% confidence interval (CI): 1.19–3.31, P=0.009; OS HR: 2.44, 95% CI: 1.37–4.34, P=0.02). Excision repair cross-complementation group 1 status did not impact DFS or OS in fluorouracil group (DFS HR: 1.16, 95% CI: 0.63–2.14, P=0.62; OS HR: 1.16, 95% CI: 0.63–2.14, P=0.63), whereas MMR status had no impact on DFS or OS in either group.

Conclusion:

Excision repair cross-complementation group 1 status is highly predictive of which patients will benefit from the addition of OX to 5-FU for stage III colon cancer. Mismatch repair status had no predictive value in this setting.

Fucoxanthin enhances cisplatin-induced cytotoxicity via NFκB-mediated pathway and downregulates DNA repair gene expression in human hepatoma HepG2 cells

Cisplain, a platinum-containing anticancer drug, has been shown to enhance DNA repair and to inhibit cell apoptosis, leading to drug resistance. Thus, the combination of anticancer drugs with nutritional factors is a potential strategy for improving the efficacy of cisplatin chemotherapy. In this study, we investigated the anti-proliferative effects of a combination of fucoxanthin, the major non-provitamin A carotenoid found in Undaria Pinnatifida, and cisplatin in human hepatoma HepG2 cells. We found that fucoxanthin (1–10 μΜ) pretreatment for 24 h followed by cisplatin (10 μΜ) for 24 h significantly decreased cell proliferation, as compared with cisplatin treatment alone. Mechanistically, we showed that fucoxanthin attenuated cisplatin-induced NFκB expression and enhanced the NFκB-regulated Bax/Bcl-2 mRNA ratio. Cisplatin alone induced mRNA expression of excision repair cross complementation 1 (ERCC1) and thymidine phosphorylase (TP) through phosphorylation of ERK, p38 and PI3K/AKT pathways. However, fucoxanthin pretreatment significantly attenuated cisplatin-induced ERCC1 and TP mRNA expression, leading to improvement of chemotherapeutic efficacy of cisplatin. The results suggest that a combined treatment with fucoxanthin and cisplatin could lead to a potentially important new therapeutic strategy against human hepatoma cells.

Molecular characterization of head and neck cancer: how close to personalized targeted therapy?

Molecular targeted therapy in head and neck squamous cell carcinoma (HNSCC) continues to make strides, and holds much promise. Cetuximab remains the sole US FDA-approved molecular targeted therapy available for HNSCC, though several new biologic agents targeting the epidermal growth factor receptor (EGFR) and other pathways are currently in the regulatory approval pipeline. While targeted therapies have the potential to be personalized, their current use in HNSCC is not personalized. This is illustrated for EGFR-targeted drugs, where EGFR as a molecular target has yet to be individualized for HNSCC. Future research needs to identify factors that correlate with response (or lack of one) and the underlying genotype-phenotype relationship that dictates this response. Comprehensive exploration of genetic and epigenetic landscapes in HNSCC is opening new frontiers to further enlighten and mechanistically inform newer as well as existing molecular targets, and to set a course for eventually translating these discoveries into therapies for patients. This opinion offers a snapshot of the evolution of molecular subtyping in HNSCC and its current clinical applicability, as well as new emergent paradigms with implications for controlling this disease in the future.

Coordinated regulation of XPA stability by ATR and HERC2 during nucleotide excision repair

ATR (ATM and Rad3-related) is an essential regulator of the nucleotide excision repair (NER) mechanism. For NER activation, ATR phosphorylates XPA, the rate-limiting factor in the NER pathway. However, the role of XPA phosphorylation at serine 196 by ATR has been elusive. Here we show that ATR-mediated XPA phosphorylation enhances XPA stability by inhibiting HERC2-mediated ubiquitination and subsequent degradation. We analyzed stabilization of XPA with substitutions of Ser 196 either to aspartate (S196D), a phosphomimetic mutation, or to alanine (S196A), a phosphodeficient mutation. Upon ultraviolet damage, ATR facilitated HERC2 dissociation from the XPA complex to induce XPA stabilization. However, this regulation was abrogated in S196A-complemented XPA-deficient cells due to persistent association of HERC2 with this XPA complex, resulting in enhanced ubiquitination of S196A. Conversely, the S196D substitution showed delayed degradation kinetics compared with the wild-type and less binding with HERC2, resulting in reduced ubiquitination of S196D. We also found that XPA phosphorylation enhanced the chromatin retention of XPA, the interaction with its binding partners following DNA damage. Taken together, our study presents a novel control mechanism in the NER pathway by regulating the steady-state level of XPA through posttranslational modifications by which ATR-mediated phosphorylation induces XPA stabilization by antagonizing HERC2-catalyzed XPA ubiquitination.

Combination erlotinib-cisplatin and Atg3-mediated autophagy in erlotinib resistant lung cancer

Tyrosine kinase inhibitors such as erlotinib are commonly used as a therapeutic agent against cancer due to its relatively low side-effect profile and, at times, greater efficacy. However, erlotinib resistance (ER) in non-small cell lung cancer is being recognized as a major problem. Therefore, understanding the mechanism behind ER and developing effective regimens are needed. Autophagy’s role in cancer has been controversial and remains unclear. In this study, we examined the effectiveness of low dose erlotinib-cisplatin combination in erlotinib resistant lung adenocarcinoma (ERPC9) cells and the role of autophagy in ER. ERPC9 cells were established from erlotinib sensitive PC9 cells. Appropriate treatments were done over two days and cell survival was quantified with Alamar Blue assay. LC3II and regulatory proteins of autophagy were measured by western blot. Small interfering RNA (siRNA) was utilized to inhibit translation of the protein of interest. In ERPC9 cells, combination treatment induced synergistic cell death and a significant decrease in autophagy. At baseline, ERPC9 cells had a significantly higher LC3II and lower p-mTOR levels compared to PC9 cells. The addition of rapamycin increased resistance and 3-methyladenine sensitized ERPC9 cells, indicating autophagy may be acting as a protective mechanism. Further examination revealed that ERPC9 cells harbored high baseline Atg3 levels. The high basal Atg3 was targeted and significantly lowered with combination treatment. siRNA transfection of Atg3 resulted in the reversal of ER; 42.0% more cells died in erlotinib-alone treatment with transfection compared to non-transfected ERPC9 cells. We reveal a novel role for Atg3 in the promotion of ER as the inhibition of Atg3 translation was able to result in the re-sensitization of ERPC9 cells to erlotinib-alone treatment. Also, we demonstrate that combination erlotinib-cisplatin is an effective treatment against erlotinib resistant cancer by targeting (down-regulating) Atg3 mediated autophagy and induction of apoptotic cell death.

Deficiency of DNA repair nuclease ERCC1-XPF promotes prostate cancer progression in a tissue recombination model

BACKGROUND

The excision repair cross complementing (ERCC1) gene product plays a vital role in the nucleotide excision repair (NER) and DNA interstrand crosslink repair pathways, which protect the genome from mutations and chromosomal aberrations, respectively. Genetic deletion of Ercc1 in the mouse causes dramatically accelerated aging. We examined the effect of Ercc1 deletion in the development of prostate cancer in a prostate recapitulation model as Ercc1 deficient mice die within four weeks of birth.

METHODS

Prostate tissues from Ercc1(-/-) mice or wild-type littermates were combined with embryonic rat urogenital mesenchyme and grown as renal grafts for a total of 8, 16, and 24 weeks before histological, expression and proliferative evaluation.

RESULTS

Invasive adenocarcinoma was observed in Ercc1(-/-) tissue recombinants but not wild-type as early as 8 weeks post-grafting. PIN-like lesions in Ercc1(-/-) tissue recombinants had more cytologic and architectural atypia than wild-type (P = 0.02, P = 0.0065, and P = 0.0003 at the 8, 16, and 24 weeks, respectively), as well as more proliferative cells (P = 0.022 and P = 0.033 at 8 and 16 weeks, respectively). With serial grafting, Ercc1(-/-) tissue recombinants progressed to a more severe histopathological phenotype more rapidly than wild-type (P = 0.011).

CONCLUSIONS

Results show that ERCC1 and by implication the NER and/or interstrand crosslink repair mechanisms protect against prostate carcinogenesis and mutations or polymorphisms affecting these DNA repair pathways may predispose prostate epithelial cells to transformation.

The significance of tumoral ERCC1 status in patients with locally advanced cervical cancer treated with chemoradiation therapy: a multicenter clinicopathologic analysis

PURPOSE

ERCC1 (excision repair cross-complementation group 1) expression has been shown to be a molecular marker of cisplatin resistance in many tumor sites, but has not been well studied in cervical cancer patients. The purpose of this study was to measure tumoral ERCC1 in patients with locally advanced cervical cancer treated with chemoradiation therapy (CRT) in a large multicenter cohort, and to correlate expression with clinical outcome parameters.

METHODS AND MATERIALS

A total of 264 patients with locally advanced cervical cancer, treated with curative-intent radical CRT from 3 major Canadian cancer centers were evaluated. Pretreatment formalin-fixed, paraffin-embedded tumor specimens were retrieved, and tissue microarrays were constructed. Tumoral ERCC1 (FL297 antibody) was measured using AQUA (R) technology. Statistical analysis was performed to determine the significance of clinical factors and ERCC1 status with progression-free survival (PFS) and overall survival (OS) at 5 years.

RESULTS

The majority of patients had International Federation of Gynecology and Obstetrics (FIGO) stage II disease (n=119, 45%); median tumor size was 5 cm. OS was associated with tumor size (HR 1.16, P=.018), pretreatment hemoglobin status (HR 2.33, P=.00027), and FIGO stage. In addition, tumoral ERCC1 status (nuclear to cytoplasmic ratio) was associated with PFS (HR 2.33 [1.05-5.18], P=.038) and OS (HR 3.13 [1.27-7.71], P=.013). ERCC1 status was not significant on multivariate analysis when the model was adjusted for the clinical factors: for PFS (HR 1.49 [0.61-3.6], P=.38); for OS (HR 2.42 [0.94-6.24] P=.067).

CONCLUSIONS

In this large multicenter cohort of locally advanced cervical cancer patients treated with radical CRT, stage, tumor size, and pretreatment hemoglobin status were significantly associated with PFS and OS. ERCC1 status appears to have prognostic impact on univariate analysis in these patients, but was not independently associated with outcome on multivariate analysis.

First-line chemotherapy in epithelial ovarian cancer

Advanced-stage epithelial ovarian cancer remains a highly lethal malignancy, despite effective cytoreductive surgery and primary chemotherapy. Phase III studies have evaluated multidrug combinations, dose-dense weekly scheduling, intraperitoneal delivery, neoadjuvant chemotherapy, maintenance therapy, and targeting of angiogenesis. Incremental gains in median progression-free or overall survival have been achieved, but without an impact on overall mortality. Data support intraperitoneal cisplatin, dose-dense weekly paclitaxel, or neoadjuvant chemotherapy with interval cytoreduction in appropriate patients. Encouraging data have emerged using antiangiogenic agents, but with questions regarding optimal timing and patient selection. The use of 3-drug combinations or maintenance chemotherapy is not supported.

Excision repair cross-complementing gene-1, ribonucleotide reductase subunit M1, ribonucleotide reductase subunit M2, and human equilibrative nucleoside transporter-1 expression and prognostic value in biliary tract malignancy

BACKGROUND

Tumor expression of excision cross-complementing gene-1 (ERCC1), human equilibrative nucleoside transporter 1 (hENT1), ribonucleotide reductase subunit M1 (RRM1), and ribonucleotide reductase subunit M2 (RRM2), is associated with the efficacy of platinum and gemcitabine chemotherapy. The authors of this report recently demonstrated that high ERCC1 and RRM2 expression levels are independent negative prognostic markers for survival in early stage pancreas cancer. The differential expression and prognostic value of these biomarkers in biliary tract malignancy (BTM) is unknown.

METHODS

In total, 63 patients who had tissue available for analysis were selected from a prospective database of all patients (n = 104) who underwent resection of BTM (intrahepatic, hilar, or distal cholangiocarcinoma; gallbladder carcinoma) between January 2000 and December 2008. Immunohistochemistry for ERCC1, hENT1, RRM1, and RRM2 expression was performed. Staining was scored by a single pathologist who was blinded to patient outcomes.

RESULTS

The median patient age was 67 years. The median overall survival (OS) was 16.2 months, and the median follow-up was 32.7 months. Only 3 BTMs (4.8%) had high ERCC1 expression, and 92.1% and 81% of BTMs exhibited high hENT1 and RRM1 expression, respectively. RRM2 expression varied, and 32% of tumors demonstrated high RRM2 expression. ERCC1 and RRM1 were not associated with OS. High RRM2 expression was associated with a trend toward improved OS (30.8 months vs 16.2 months; P = .06), and high hENT1 expression was associated with improved OS (17.7 months vs 9.5 months; P = .04).

CONCLUSIONS

Most BTMs exhibited low ERCC1 expression and high hENT1 and RRM1 expression, whereas RRM2 expression levels varied. High expression of hENT1 was associated with improved OS. These findings may have implications for the selection of chemotherapy agents (gemcitabine vs platinum) and the stratification of patients in chemotherapy trials that assess outcome.

Role of excision repair cross-complementation 1 expression as a prognostic marker for response to radiotherapy in early-stage laryngeal cancer

BACKGROUND

High expression of excision repair cross-complementation 1 (ERCC1) predicts for resistance to platinum-based chemotherapy or chemoradiotherapy. We evaluated the prognostic value of ERCC1 expression in a cohort of laryngeal cancer treated with radiotherapy alone.

METHODS

ERCC1 expression was examined by immunohistochemical analysis of tissue microarrays constructed from 123 patients with stages I-II laryngeal squamous cell carcinoma treated with standard radiotherapy.

RESULTS

ERCC1 expression did not correlate with clinicopathologic risk factors, local control, or overall survival. At 5 years, local control was 75% versus 71% (p = .78) and overall survival was 68% versus 54% (p = .65), for nonexpressors and expressors of ERCC1, respectively. On multivariate analysis, T classification predicted for local control, and T classification and age predicted for overall survival.

CONCLUSIONS

ERCC1 expression did not predict for radiotherapy resistance or worse survival. Therefore, radiotherapy remains an effective treatment in tumors with high ERCC1 expression.

Ovarian carcinoma tumor-initiating cells have a mesenchymal phenotype

Solid tumors appear to contain a subpopulation of cells (tumor-initiating cells, TICs) that not only drives and sustains tumor growth, but is possibly responsible for recurrence. We isolated, after enzymatic digestion of primary ovarian carcinoma samples, a subpopulation of cells propagating as non-adherent spheres in medium suitable for tumor stem cells. These cells were able to self-renew in vitro, as suggested by PKH-26 staining studies, were tumorigenic and acquired an epithelial morphology when grown in FBS-supplemented medium, losing their tumorigenic potential. Interestingly, the tumorigenic potential of PKH-26 (high) - and PKH-26 (neg) -sorted cells was similar. These TIC-enriched cultures showed higher levels of genes involved in stemness than differentiated cells derived from them and were more resistant to the cytotoxic effects of some drugs but equally sensitive to others. The higher level of ABCG2 efflux pump could explain increased resistance to taxol and VP16, and higher levels of genes involved in nucleotide excision repair partially explain the resistance to cisplatin. These cells express mesenchymal markers, and epithelial transition could be induced when cultured in differentiating conditions, with a loss of invasive potential. These data suggest that ovarian cancer is a stem cell disease and should help elucidate the role of these cells in the aggressive phenotype of this tumor and find new therapeutic strategies to reduce resistance to current chemotherapeutic drugs.

Co-expression of ERCC1 and Snail is a prognostic but not predictive factor of cisplatin-based neoadjuvant chemotherapy for bladder cancer

Neoadjuvant chemotherapy (NC) for bladder cancer has been reported to significantly improve the 5-year survival rate. The aim of the present study was to examine the roles of ERCC1 and Snail in determining the response to chemotherapy in bladder cancer treated with NC and radical cystectomy (RC). The expression of the Snail and ERCC1 proteins was determined by immunohistochemical staining of specimens obtained from 58 patients with bladder tumors treated with NC and RC. The correlation between clinical response and the expression of Snail and ERCC1 was investigated. Snail and ERCC1 were co-expressed in 24 (41.4%) of the 58 patients. A marked correlation was found between the expression of Snail and ERCC1 (P=0.001). The co-expression of Snail and ERCC1 was not able to predict pathological complete response (P=0.202). Results of the univariate analysis revealed that the co-expression of Snail and ERCC1 predicted shorter disease-free survival (DFS) and overall survival (OS) than the negative expression of Snail and/or ERCC1. Moreover, the co-expression of ERCC1 and Snail was the only predictive factor for both DFS (P=0.029) and OS (P=0.040). The expression of Snail was correlated with that of ERCC1 and the co-expression of Snail and ERCC1 was the only significant predictive factor of shorter DFS and OS in patients with bladder cancer treated with NC and RC.

Combined analysis of mRNA expression of ERCC1, BAG-1, BRCA1, RRM1 and TUBB3 to predict prognosis in patients with non-small cell lung cancer who received adjuvant chemotherapy

BACKGROUND

The aim of this study was to investigate prognostic value of excision repair cross-complementing 1 (ERCC1), BCL2-associated athanogene (BAG-1), the breast and ovarian cancer susceptibility gene 1 (BRCA1), ribonucleotide reductase subunit M1 (RRM1) and class III β-tubulin (TUBB3) in patients with non-small cell lung cancer (NSCLC) who received platinum- based adjuvant chemotherapy.

METHODS

Messenger RNA expressions of these genes were examined in 85 tumor tissues and 34 adjacent tissue samples using semi-quantitative RT-PCR. The expressions of these five genes were analyzed in relation to chemotherapy and progression-free survival (PFS) and overall survival (OS). Seventy-four patients were enrolled into chemotherapy.

RESULTS

Patients with ERCC1 or BAG-1 negative expression had a significantly longer PFS (P = 0.001 and P = 0.001) and OS (P = 0.001 and P = 0.001) than those with positive expression. Patients with negative ERCC1 and BAG-1 expression benefited more from platinum regimen (P = 0.001 and P = 0.002). Patients with BRCA1 negative expression might have a longer OS (P = 0.052), but not PFS (P = 0.088) than those with BRCA1 positive expression. A significant relationship was observed between the mRNA expression of ERCC1 and BAG-1 (P = 0.042). In multivariate analysis, ERCC1 and BAG-1 were significantly favorable factors for PFS (P = 0.018 and P = 0.017) and OS (P = 0.027 and P = 0.022).

CONCLUSIONS

ERCC1 and BAG-1 are determinants of survival after surgical treatment of NSCLC, and its mRNA expression in tumor tissues could be used to predict the prognosis of NSCLC treated by platinum.

Update of randomized trials in first-line treatment

Advanced-stage epithelial ovarian cancer remains a highly lethal malignancy, in spite of effective cytoreductive surgery and primary chemotherapy. Randomized phase III trials have provided the most consistent platform for the evaluation of new treatment interventions. Recently completed and ongoing international phase III studies in the primary disease setting, summarized and analyzed in the present review, have evaluated multidrug combinations, weekly scheduling, intraperitoneal delivery, neoadjuvant chemotherapy, maintenance therapy and targeting of angiogenesis. The data from these studies have supported the consideration of intraperitoneal cisplatin, dose-dense weekly scheduling of paclitaxel or neoadjuvant chemotherapy with interval cytoreductive surgery in appropriate patient populations. Contrary to this, the use of three-drug combinations or maintenance chemotherapy is not supported by phase III data. Encouraging data have emerged using antiangiogenic agents, but with questions regarding optimal dose, timing and duration. Ongoing and planned trials will evaluate the inhibition of DNA repair and tailored treatment in accordance with tumor molecular profiles.

Progress in personalizing chemotherapy for bladder cancer

Platinum-based chemotherapy is commonly used for the treatment of locally advanced and metastatic bladder cancer. However, there are currently no methods to predict chemotherapy response in this disease setting. A better understanding of the biology of bladder cancer has led to developments of molecular biomarkers that may help guide clinical decision making. These biomarkers, while promising, have not yet been validated in prospective trials and are not ready for clinical applications. As alkylating agents, platinum drugs kill cancer cells mainly through induction of DNA damage. A microdosing approach is currently being tested to determine if chemoresistance can be identified by measuring platinum-induced DNA damage using highly sensitive accelerator mass spectrometry technology. The hope is that these emerging strategies will help pave the road towards personalized therapy in advanced bladder cancer.

Thymidylate synthase and thymidine phosphorylase mRNA expression in primary lesions using laser capture microdissection is useful for prediction of the efficacy of FOLFOX treatment in colorectal cancer patients with liver metastasis

Chemotherapy with FOLFOX, which is a combination of 5-fluorouracil (5-FU)/leucovorin (LV) and oxaliplatin, has been used worldwide for the treatment of metastatic colorectal cancer patients. The aim of this study was to examine the candidates for predictors of the efficacy of the FOLFOX treatment regimen in colorectal cancer patients with liver metastasis, using formalin-fixed paraffin-embedded specimens. We investigated the mRNA levels of thymidylate synthase (TS), thymidine phosphorylase (TP), dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyltransferase (OPRT) and excision repair cross-complementing 1 (ERCC1) in 70 primary lesions and 30 liver metastatic lesions of colorectal cancer patients, using laser capture microdissection and real-time PCR methods. We then analyzed the correlation between their expression in primary lesions and those in corresponding liver metastatic lesions (n=30) and the relationship between their expression in the primary lesions and the efficacy of mFOLFOX6 in 45 colorectal cancer patients with unresectable liver metastasis. The gene expression in primary lesions positively correlated with those in corresponding liver metastatic lesions. The profiles of gene expression of primary lesions strongly correlated with those of synchronous liver metastatic lesions compared to that of metachronous liver metastatic lesions. TS and TP mRNA levels in the patients with complete response, partial response or stable disease (n=34) were significantly lower compared to those in the patients with progressive disease (n=11) (p=0.017 and p=0.04, respectively). Our results indicated that TS and TP mRNA expression profiles in primary lesions are sufficient to estimate the mRNA expression profiles in synchronous liver metastatic lesions compared to metachronous liver metastatic lesions. Additionally, these profiles may be useful predictors in the identification of eligible colorectal cancer patients with liver metastasis for FOLFOX treatment.

DNA repair gene excision repair cross complementing-group 1 (ERCC1) in head and neck squamous cell carcinoma: analysis of methylation and polymorphism (G19007A), protein expression and association with epidemiological and clinicopathological factors

AIMS

To evaluate the associations of excision repair cross complementing-group 1 (ERCC1) (DNA repair protein) (G19007A) polymorphism, methylation and immunohistochemical expression with epidemiological and clinicopathological factors and with overall survival in head and neck squamous cell carcinoma (HNSCC) patients.

METHODS AND RESULTS

The study group comprised 84 patients with HNSCC who underwent surgery and adjuvant radiotherapy without chemotherapy. Bivariate and multivariate analyses were used. The allele A genotype variant was observed in 79.8% of the samples, GG in 20.2%, GA in 28.6% and AA in 51.2%. Individuals aged more than 45 years had a higher prevalence of the allelic A variant and a high (83.3%) immunohistochemical expression of ERCC1 protein [odds ratio (OR) = 4.86, 95% confidence interval (CI): 1.2-19.7, P = 0.027], which was also high in patients with advanced stage (OR=5.04, 95% CI: 1.07-23.7, P = 0.041). Methylated status was found in 51.2% of the samples, and was higher in patients who did not present distant metastasis (OR = 6.67, 95% CI: 1.40-33.33, P = 0.019) and in patients with advanced stage (OR = 5.04, 95% CI: 1.07-23.7, P = 0.041). At 2 and 5 years, overall survival was 55% and 36%, respectively (median = 30 months).

CONCLUSION

Our findings may reflect a high rate of DNA repair due to frequent tissue injury during the lifetime of these individuals, and also more advanced disease presentation in this population with worse prognosis.

A Review of ERCC1 Gene in Bladder Cancer: Implications for Carcinogenesis and Resistance to Chemoradiotherapy

The excision repair cross-complementing group 1 (ERCC1) gene performs a critical incision step in DNA repair and is reported to be correlated with carcinogenesis and resistance to drug or ionizing radiation therapy. We reviewed the correlation between ERCC1 and bladder cancer. In carcinogenesis, several reports discussed the relation between ERCC1 single nucleotide polymorphisms and carcinogenesis in bladder cancer only in case-control studies. Regarding the relation between ERCC1 and resistance to chemoradiotherapy, in vitro and clinical studies indicate that ERCC1 might be related to resistance to radiation therapy rather than cisplatin therapy. It is controversial whether ERCC1 predicts prognosis of bladder cancer treated with cisplatin-based chemotherapy. Tyrosine kinase receptors or endothelial-mesenchymal transition are reported to regulate the expression of ERCC1, and further study is needed to clarify the mechanism of ERCC1 expression and resistance to chemoradiotherapy in vitro and to discover novel therapies for advanced and metastatic bladder cancer.

Improving the clinical risk score: an analysis of molecular biomarkers in the era of modern chemotherapy for resectable hepatic colorectal cancer metastases

BACKGROUND

The prognostic relevance of variations in expression of specific tumor genes in colorectal cancer liver metastases (CRCLMs) in patients treated with resection and modern chemotherapy is not known.

METHODS

Patients submitted to liver resection for CRCLM between January 2000 and October 2007 were studied. A clinical risk score (CRS; range, 0-5) was calculated for each patient. RNA was extracted from histologically confirmed tumor isolates, and using real-time polymerase chain reaction (PCR) studies, we assessed the quantitative expression of 12 genes with potential importance in chemotherapy resistance and tumor progression, including thymidylate synthase (TS; 5-fluorouracil), excision repair cross complementing gene-1, and xeroderma pigmentosum groups A through G (oxaliplatin), topoisomerase-I (irinotecan), c-met, and hepatocyte growth factor. Primary outcomes were recurrence-free survival (RFS) and disease-specific survival (DSS) after hepatic resection.

RESULTS

One-hundred fifty-five patients with good quality tumor mRNA were identified. Median follow-up was 32 months for survivors, and the median CRS was 2. Eighty-seven patients (56%) received preoperative chemotherapy, and 124 (80%) received postoperative chemotherapy. Median RFS for all patients was 13 months, and 3-year DSS was 69%. Median RFS and 3-year DSS for patients with an increased CRS (3-5) was lower (7 vs 18 months [P < .0001] and 50% vs. 80% [P < .0001], respectively). Of the 12 genes studied, only increased TS expression was associated with a lower RFS (hazard ratio, 1.16; 95% confidence interval, 1.0-1.3; P = .03) and DSS (hazard ratio, 1.25; 95% confidence interval, 1.0-1.5; P = .03). Median RFS and 3-year DSS for patients with increased TS expression was decreased (9 vs. 15 months [P = .03] and 48% vs. 82% [P = .001], respectively). TS expression had prognostic value that was independent of CRS on multivariate analysis.

CONCLUSION

In patients with hepatic CRCLM treated with resection and modern chemotherapy, increased expression of TS improves outcome stratification and appears to be a useful biomarker.

Automated ERCC1 immunochemistry on hybrid cytology/tissue microarray of malignant effusions: evaluation of antibodies 8F1 and D-10

Background

The excision repair cross-complementation group 1 (ERCC1) protein is the key enzyme of the nucleotide excision repair (NER) pathway. Loss of protein expression on immunohistochemistry is predictive for platinum-based chemotherapy response. Frequently, the diagnosis of malignancy is made on cytologic effusion samples. Therefore, we evaluated the staining quality of monoclonal anti-ERCC1 antibodies 8F1 and D-10 on microarrays of malignant pleural and peritoneal effusions by automated immunochemistry.

Methods

Cores from effusion cell blocks of 117 patients with > 40 malignant cell clusters per whole section (pleural n = 75, peritoneal n = 42) were assembled together with 30 histologic control cores from large tissue blocks (lung, breast and ovarian carcinoma, each n = 10) on hybrid cytology-tissue microarrays (C/TMA). Four immunochemistry protocols (Mab 8F1 and D-10, CC1-mono Ventana and H2-60 Bond automat) were performed. Immunoreactivity was semi-quantitatively scored for intensity and intensity multiplied by percentage staining (H-score).

Results

Tumors were classified into female genital tract carcinoma (n = 39), lung adenocarcinoma (n = 23), mesothelioma (n = 15), unknown primary (n = 14), breast carcinoma (n = 10), gastro-intestinal carcinoma (n = 12) and other (n = 4). On both platforms, reproducible nuclear ERCC1 immunoreactivity was achieved with both antibodies, although D-10 was slightly weaker and presented more background staining as well as more variation in the low expression range. No significant differences were found between cytologic and histologic cores. Using the 8F1 CC1-mono protocol, lung and breast carcinomas had lower ERCC1 expression in comparison to the other entities (p-value < 0.05).

Conclusions

Cytology microarrays (CMA) are suitable for investigation of clinical biomarkers and can be combined with conventional TMA's. Dichotomization of ERCC1 immunoreactivity scores is most suitable for patient stratification since definition of negativity is antibody-dependent.

Synergistic effects of combination with fludarabine and carboplatin depend on fludarabine-mediated inhibition of enhanced nucleotide excision repair in leukemia

Overcoming drug resistance remains a major obstacle to curing relapsed or refractory lymphoma and obtaining a beneficial long-term prognosis for patients, despite the introduction of several salvage regimens to date. Our ultimate purpose is to establish a standard second-line salvage chemotherapy regimen for curing relapsed/refractory lymphoma. In this basic pre-clinical study, we evaluated a combination regimen consisting of 9-β-D: -arabinofuranosyl-2-fluoroadenine (F-araA) and carboplatin that targeted nucleotide excision repair (NER) of DNA in five representative leukemia lineages in vitro. Isobologram analysis demonstrated that simultaneous exposure to these two drugs produced synergistic interactions in U937 and K562 cells, in which lines showed enhanced NER activity by the measurement of UV or drug-induced DNA strand break (comet assay), or quantitation of ERCC1 mRNA (RT-PCR), a key enzyme for NER. Histone γH2AX formation was synergistically induced, but no such formation was observed after exposure to either agent alone in K562 cells. In summary, we synergistically inhibited the NER activity of leukemia cells by treating them with a combination of F-araA and carboplatin, suggesting that this combinatory regimen could be used as a novel salvage therapy for refractory or drug-resistant lymphoma.

Novel compounds in the treatment of lung cancer: current and developing therapeutic agents

Lung cancer is the leading cause of cancer-related death in the United States. Though incremental advances have been made in the treatment of this devastating disease during the past decade, new therapies are urgently needed. Traditional cytotoxic agents have been combined with other modalities with improved survival for early-stage patients. Newer cytotoxic agents targeting the same or different mechanisms have been developed at different stages. Optimization of various chemotherapy regimens in different settings is one of the aims of current clinical trials. Some predictive biomarkers (eg, excision repair cross-complementing 1, ERCC1) and histotypes (eg, adenocarcinoma) are found to be associated with resistance/response to some cytotoxic drugs. Another notable advance is the addition of targeted therapy to lung cancer treatment. Targeted agents such as erlotinib and bevacizumab have demonstrated clinical benefits and gained Food and Drug Administration approval for lung cancer. More agents targeting various signaling pathways critical to lung cancer are at different stages of development. Along with the effort of new targeted drug discovery, biomarkers such as epidermal growth factor receptor and anaplastic lymphoma kinase mutations have proven useful for patient selection, and more predictive biomarkers have been actively evaluated in non-small cell lung cancer. The paradigm of lung cancer treatment has shifted towards biomarker-based personalized medicine.

Expression of DNA repair genes in ovarian cancer samples: biological and clinical considerations

The purpose of this study was to investigate retrospectively the mRNA expression of genes involved in different DNA repair pathways implicated in processing platinum-induced damage in 171 chemotherapy-naïve ovarian tumours and correlate the expression of the different genes with clinical parameters. The expression of genes involved in DNA repair pathways (PARP1, ERCC1, XPA, XPF, XPG, BRCA1, FANCA, FANCC, FANCD2, FANCF and PolEta), and in DNA damage transduction (Chk1 and Claspin) was measured by RT-PCR in 13 stage I borderline and 77 stage I and 88 III ovarian carcinomas. ERCC1, XPA, XPF and XPG genes were significantly less expressed in stage III than in stage I carcinoma; BRCA1, FANCA, FANCC, FANCD2 gene expressions were low in borderline tumours, higher in stage I carcinomas and lower in stage III samples. High levels of ERCC1, XPA, FANCC, XPG and PolEta correlated with an increase in Overall Survival (OS) and Progression Free Survival (PFS), whilst high BRCA1 levels were associated with PFS on univariate analysis. With multivariate analyses no genes retained an association when adjusted by stage, grade and residual tumour. A tendency towards a better PFS was observed in patients with the highest level of ERCC1 and BRCA1 after platinum-based therapy than those given both platinum and taxol. The expression of DNA repair genes differed in borderline stage I, stage I and stage III ovarian carcinomas. The role of DNA repair genes in predicting the response in ovarian cancer patients seems far from being established.

Excision repair cross-complementing group 1 may predict the efficacy of chemoradiation therapy for muscle-invasive bladder cancer

PURPOSE

Chemoradiation therapy (CRT) is now widely recognized as bladder-preserving therapy for muscle-invasive bladder cancer (MIBC). However, some patients who fail CRT may miss the chance to be cured by cystectomy. Therefore, it is important to select patients with MIBC who are expected to have a good response to CRT. Several reports indicate that the excision repair cross-complementing group 1 (ERCC1) gene is associated with resistance to cisplatin and radiation therapy. In this study, we examined the correlation between ERCC1 and CRT in vitro and in vivo in bladder cancer.

EXPERIMENTAL DESIGN

Bladder cancer cell lines T24, 5637, Cl8-2 (multidrug-resistant subline of T24), and CDDP10-3 (cisplatin-resistant subline of T24) were used for in vitro assays to measure ERCC1 expression level and growth inhibition with cisplatin or ionizing radiation (IR). We then examined by immunohistochemistry that whether ERCC1 nuclear staining correlates with the efficacy of CRT using cisplatin in 22 patients with MIBC.

RESULTS

Cl8-2 cells expressed ERCC1 mRNA 5.96-fold higher than did T24. Cl8-2 and CDDP10-3 were more resistant to cisplatin or IR than was T24. Resistance to IR, but not to cisplatin, was removed by suppressing ERCC1 using siRNA in both Cl8-2 and CDDP10-3 cells. In immunohistochemistry with ERCC1, 6 of 8 positive cases did not have complete response to CRT, whereas 12 of 14 negative cases had complete response. Sensitivity and specificity were 75% and 85.7%, respectively (P = 0.008).

CONCLUSION

Although further study is needed, ERCC1 expression level may predict the efficacy of CRT for MIBC.