ERCC1, hRad51, and BRCA1 protein expression in relation to tumour response and survival of stage III/IV NSCLC patients treated with chemotherapy

Up-Regulation of FSTL3, Regulated by lncRNA DSCAM-AS1/miR-122-5p Axis, Promotes Proliferation and Migration of Non-Small Cell Lung Cancer Cells

Background

Follistatin-like 3 (FSTL3) binds and inactivates activin, a growth factor with cell growth and differentiation. Previous studies reported that it is overexpressed in invasive breast cancers, and its expression and function in non-small cell lung cancer (NSCLC) remain unclear.

Materials and Methods

Immunohistochemistry was employed to probe the expression of FSTL3 in NSCLC tissues. Real-time PCR (RT-PCR) was applied to detect the expression of lncRNA DSCAM-AS1 and miR-122-5p. A549 cells and H1299 cells were used as cell models. The biological influence of FSTL3 on cells was studied using CCK-8 assay, wound healing assay and transwell assay in vitro, respectively. In vivo subcutaneous xenotransplanted tumor model and tail vein injection model in mice were also constructed to validate the roles of FSTL3. Interactions between miR-122-5p and FSTL3, DSCAM-AS1 and miR-122-5p were determined by bioinformatics analysis, RT-PCR, and dual-luciferase reporter assay.

Results

FSTL3 and DSCAM-AS1 were remarkably up-regulated in NSCLC samples, and miR-122-5p was down-regulated. FSTL3 was associated with worse prognosis of NSCLC patients. FSTL3 knockdown markedly inhibited the viability, migration and invasion of NSCLCs in vitro and in vivo. DSCAM-AS1 could down-regulate miR-122-5p via sponging it, and FSTL3 was a target gene of miR-122-5p.

Conclusion

Taken together, our study identified that FSTL3 was a new oncogene of NSCLC, which was regulated by DSCAM-AS1 and miR-122-5p. These findings suggested that FSTL3, DSCAM-AS1 and miR-122-5p might serve as a new valuable therapeutic target for NSCLC.

Prognostic role of beclin-1 in locally advanced non-small cell lung cancer in patients receiving docetaxel-platinum induction chemotherapy

BACKGROUND/AIMS

The outcome of local treatment for advanced non-small cell lung cancer (NSCLC) remains poor, with therapies such as induction chemotherapy (IC) yielding conflicting results. This study aimed to assess the clinicopathologic and prognostic significance of the excision repair cross-complementation group 1 (ERCC1), beclin-1, and glucose-regulated protein of molecular mass 78 (GRP78) in patients with locally advanced NSCLC receiving docetaxel-platinum IC, along with efficacy and safety.

METHODS

This is a retrospective observational cohort study. We reviewed medical records of 31 NSCLC patients receiving docetaxel-platinum IC, and conducted immunohistochemical staining of ERCC1, beclin-1, and GRP78.

RESULTS

Response rate was 67.8% with 10.7 months of median relapse-free survival (RFS) and 23.1 months of median overall survival (OS), and no treatment-related death was reported. High expression of ERCC1, beclin-1, and GRP78 was identified in 67.7%, 87.1%, and 67.7%, respectively. Expression of ERCC1 and GRP78 did not reveal statistical significance in survival, whereas high beclin-1 expression revealed longer OS (7.6 months vs. 23.2 months; log-rank p = 0.024). In multivariate analysis, histologic differentiation (hazard ratio [HR], 3.48; p < 0.001), stage (HR, 8.5; p = 0.024), and adjuvant treatment (HR, 16.1; p = 0.001) were related to RFS, and in OS, stage (HR, 5.4; p = 0.037), adjuvant treatment (HR, 8.6; p = 0.004), and beclin-1 expression (HR, 8.2; p = 0.011) were identified as significant prognostic factors.

CONCLUSION

Our findings suggest that high beclin-1 expression predicts longer survival in locally advanced NSCLC and docetaxel-platinum IC is a treatment option that deserves consideration.

MSH2/BRCA1 expression as a DNA-repair signature predicting survival in early-stage lung cancer patients from the IFCT-0002 Phase 3 Trial

Introduction

DNA repair is a double-edged sword in lung carcinogenesis. When defective, it promotes genetic instability and accumulated genetic alterations. Conversely these defects could sensitize cancer cells to therapeutic agents inducing DNA breaks.

Methods

We used immunohistochemistry (IHC) to assess MSH2, XRCC5, and BRCA1 expression in 443 post-chemotherapy specimens from patients randomized in a Phase 3 trial, comparing two neoadjuvant regimens in 528 Stage I-II non-small cell lung cancer (NSCLC) patients (IFCT-0002). O6MGMT promoter gene methylation was analyzed in a subset of 208 patients of the same trial with available snap-frozen specimens.

Results

Median follow-up was from 90 months onwards. Only high BRCA1 (n = 221, hazard ratio [HR] = 1.58, 95% confidence interval [CI] [1.07-2.34], p = 0.02) and low MSH2 expression (n = 356, HR = 1.52, 95% CI [1.11-2.08], p = 0.008) significantly predicted better overall survival (OS) in univariate and multivariate analysis. A bootstrap re-sampling strategy distinguished three patient groups at high (n = 55, low BRCA1 and high MSH2, median OS >96 months, HR = 2.5, 95% CI [1.45-4.33], p = 0.001), intermediate (n = 82, median OS = 73.4 p = 0.0596), and low (high BRCA1 and low MSH2, n = 67, median OS = ND, HR = 0.51, 95% CI [0.31-0.83], p = 0.006) risk of death.

Interpretation

DNA repair protein expression assessment identified three different groups of risk of death in early-stage lung cancer patients, according to their tumor MSH2 and BRCA1 expression levels. These results deserve prospective evaluation of MSH2/BRCA1 theranostic value in lung cancer patients treated with combinations of DNA-damaging chemotherapy and drugs targeting DNA repair, such as Poly(ADP-ribose) polymerase (PARP) inhibitors.

Evaluation of Prediction of Polymorphisms of DNA Repair Genes on the Efficacy of Platinum-Based Chemotherapy in Patients With Non-Small Cell Lung Cancer: A Network Meta-Analysis

This network meta-analysis (NMA) was conducted to compare the predictive value of 14 SNPs in eight DNA repair genes on the efficacy of platinum-based chemotherapy in patients with non-small cell lung cancer (NSCLC). These included ERCC1 (rs11615, rs3212986, rs3212948), XRCC1 (rs25487, rs25489, rs1799782), XPD (rs13181, rs1799793), XPG (rs1047768, rs17655), XPA (rs1800975), XRCC3 (rs861539), APE1 (rs3136820), and RRM1 (rs1042858). The PubMed and Cochrane library databases were reviewed from their inception to February 2017 and studies which met our inclusion criteria were included in our investigation. This network meta-analysis combines direct and indirect evidence to assess the predictive value of 14 SNPs in eight DNA repair genes on the efficacy of platinum-based chemotherapy in NSCLC. We evaluated the predictive value through the use of the odd ratios (OR) and drawing surface under the cumulative ranking curves (SUCRA). A total of 26 eligible cohort studies were enrolled in this NMA. The pairwise meta-analysis indicated that in terms of overall response ratio (ORR), ERCC1 (rs11615), XRCC1 (rs25487, rs1799782), and XPD (rs13181) polymorphisms are associated with the efficacy of platinum-based chemotherapy in NSCLC. The result of this NMA suggests that there is no significant difference in predictive value of 8 DNA repair genes on the efficacy of platinum-based chemotherapy in NSCLC patients. The rank of SUCRA values of the 14 SNPs in the eight DNA repair genes were: XPD (rs1799793)→ERCC1 (rs3212986)→XPA(rs1800975)→ERCC1(rs3212948)→XRCC1(rs25487)→XRCC3(rs861539)→APE1(rs3136820)→ERCC1(rs11615)→XRCC1(rs1799782)→RRM1(rs1042858)→XPD(rs13181)→XPG (rs1047768)→XPG(rs17655)→XRCC1(rs25489). ERCC1(rs11615), XRCC1(rs25487, rs1799782) and XPD(rs13181) polymorphisms were better predictors in evaluating the efficacy of platinum-based chemotherapy in NSCLC patients. J. Cell. Biochem. 118: 4782-4791, 2017. © 2017 Wiley Periodicals, Inc.

ERCC1 Expression in Metastatic Triple Negative Breast Cancer Patients Treated with Platinum-Based Chemotherapy

Background: Possible targeted therapies for metastatic triple negative breast cancer (TNBC) include cytotoxic chemotherapy that causes interstrand breaks (platinum-based drugs). The excision repair cross-complementation 1 (ERCC1) enzyme plays an essential role in the nucleotide excision repair pathway, removing platinum-induced DNA adducts and contributing to cisplatin resistance. Detecting ERCC1 overexpression is important in considering treatment options for metastatic TNBC, including individualized approaches to therapy, and may facilitate improved responses or reduction of unnecessary toxicity. We hypothesized that assigning cisplatin based on pretreatment ERCC1 expression would improve response and survival. This study was conducted to assess the impact of ERCC1 expression on PFS, OS and response rates in metastatic triple negative breast cancer patients treated with platinum-based chemotherapy. Methods: From June 2012 to November 2013, 52 metastatic triple negative breast cancer patients were enrolled. ERCC1 protein expression was detected from pretreatment biopsies by Immunohistochemistry. All patients received cisplatin plus paclitaxel. The primary end point was the impact of ERCC1 expression on PFS and OS. Results: 34 patients (65.4%) showed positive ERCC1 expression while 18 (34.6%) proved negative. Positive ERCC1 expression was associated with short PFS (median, 5 months vs. 7 months; P = 0.043), short OS (median, 9 months vs. 11 months; P = 0.033) and poor response to cisplatin based chemotherapy (P = 0.046). Conclusions: This prospective study further validated ERCC1 as a reliable biomarker for customized chemotherapy in metastatic triple negative breast cancer patients. High expression of ERCC1 was thereby fond to be significantly associated with poor outcome in patients treated with platinum based chemotherapy.

The Challenges of Validating in Precision Medicine: The Case of Excision Repair Cross-Complement Group 1 Diagnostic Testing

Personalized medicine relies upon the successful identification and translation of predictive biomarkers. Unfortunately, biomarker development has often fallen short of expectations. To better understand the obstacles to successful biomarker development, we systematically mapped research activities for a biomarker that has been in development for at least 12 years: excision repair cross-complement group 1 protein (ERCC1) as a biomarker for predicting clinical benefit with platinum-based chemotherapy in non-small cell lung cancer. We found that although research activities explored a wide range of approaches to ERCC1 testing, there was little replication or validation of techniques, and design and reporting of results were generally poor. Our analysis points to problems with coordinating and standardizing research in biomarker development. Clinically meaningful progress in personalized medicine will require concerted efforts to address these problems. In the interim, health care providers should be aware of the complexity involved in biomarker development, cautious about their near-term clinical value, and conscious of applying only validated diagnostics in the clinic.

THE ONCOLOGIST

2017;22:89-96 IMPLICATIONS FOR PRACTICE: : Many hospitals, policy makers, and scientists have made ambitious claims about the promise of personalizing cancer care. When one uses a case example of excision repair cross-complement group 1 protein-a biomarker that has a strong biological rationale and that has been researched for 12 years-the current research environment seems poorly suited for efficient development of biomarker tests. The findings provide grounds for tempering expectations about personalized cancer care-at least in the near term-and shed light on the current gap between the promise and practice of personalized medicine.

Ercc1 Deficiency Promotes Tumorigenesis and Increases Cisplatin Sensitivity in a Tp53 Context-Specific Manner

KRAS-mutant lung adenocarcinoma is among the most common cancer entities and, in advanced stages, typically displays poor prognosis due to acquired resistance against chemotherapy, which is still largely based on cisplatin-containing combination regimens. Mechanisms of cisplatin resistance have been extensively investigated, and ERCC1 has emerged as a key player due to its central role in the repair of cisplatin-induced DNA lesions. However, clinical data have not unequivocally confirmed ERCC1 status as a predictor of the response to cisplatin treatment. Therefore, we employed an autochthonous mouse model of Kras-driven lung adenocarcinoma resembling human lung adenocarcinoma to investigate the role of Ercc1 in the response to cisplatin treatment. Our data show that Ercc1 deficiency in Tp53-deficient murine lung adenocarcinoma induces a more aggressive tumor phenotype that displays enhanced sensitivity to cisplatin treatment. Furthermore, tumors that relapsed after cisplatin treatment in our model develop a robust etoposide sensitivity that is independent of the Ercc1 status and depends solely on previous cisplatin exposure. Our results provide a solid rationale for further investigation of the possibility of preselection of lung adenocarcinoma patients according to the functional ERCC1- and mutational TP53 status, where functionally ERCC1-incompetent patients might benefit from sequential cisplatin and etoposide chemotherapy.

IMPLICATIONS

This study provides a solid rationale for the stratification of lung adenocarcinoma patients according to the functional ERCC1- and mutational TP53 status, where functionally ERCC1-incompetent patients could benefit from sequential cisplatin and etoposide chemotherapy. Mol Cancer Res; 14(11); 1110-23. ©2016 AACR.

Biomarkers for efficacy of adjuvant chemotherapy following complete resection in NSCLC stages I-IIIA

Biomarkers may be useful when deciding which nonsmall cell lung cancer (NSCLC) patients may benefit from adjuvant chemotherapy following complete resection and which chemotherapeutic agents may be used preferably in individual patients in order to maximise survival.

A literature search covering the period from 2003 to May, 2014 was conducted using PubMed and the following search terms: “non-small cell lung cancer”, “NSCLC”, “adjuvant chemotherapy”, “randomized”, “randomised”, “biomarkers”, “prognostic”, “predictive”. This review focuses on current knowledge of biomarkers for prognosis or efficacy of adjuvant treatment following complete resection in stage I–IIIA NSCLC patients.

This review includes results on 18 different biomarkers and five gene profiles. A statistically significant prognostic impact was reported for: iNTR, TUBB3, RRM1, ERCC1, BRCA1, p53, MRP2, MSH2, TS, mucin, BAG-1, pERK1/2, pAkt-1, microRNA, TopIIA, 15-gene profile, 92-gene profile, 31-gene profile and 14-gene profile. A statistically significant predictive impact was reported for: ERCC1, p53, MSH2, p27, TUBB3, PARP1, ATM, 37-gene profile, 31-gene profile, 15-gene profile and 92-gene profile.

Uncertainties regarding the optimal analysis method and cut-off levels for the individual markers may blur the prognostic or predictive signals. None of the possible predictive markers have been validated in prospective trials. Thus, there are no biomarkers ready to use in an adjuvant setting in NSCLC.

Further investigation and validation is required to explore biomarkers in completely resected NSCLC stage I–IIIAhttp://ow.ly/M0leE

Astaxanthin down-regulates Rad51 expression via inactivation of AKT kinase to enhance mitomycin C-induced cytotoxicity in human non-small cell lung cancer cells

Astaxanthin has been demonstrated to exhibit a wide range of beneficial effects, including anti-inflammatory and anti-cancer properties. However, the molecular mechanism of astaxanthin-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. Rad51 plays a central role in homologous recombination, and studies show that chemo-resistant carcinomas exhibit high levels of Rad51 expression. In this study, astaxanthin treatment inhibited cell viability and proliferation of two NSCLC cells, A549 and H1703. Astaxanthin treatment (2.5-20 μM) decreased Rad51 expression and phospho-AKT(Ser473) protein level in a time and dose-dependent manner. Furthermore, expression of constitutively active AKT (AKT-CA) vector rescued the decreased Rad51 mRNA and protein levels in astaxanthin-treated NSCLC cells. Combined treatment with phosphatidylinositol 3-kinase (PI3K) inhibitors (LY294002 or wortmannin) further decreased the Rad51 expression in astaxanthin-exposed A549 and H1703 cells. Knockdown of Rad51 expression by transfection with si-Rad51 RNA or cotreatment with LY294002 further enhanced the cytotoxicity and cell growth inhibition of astaxanthin. Additionally, mitomycin C (MMC) as an anti-tumor antibiotic is widely used in clinical NSCLC chemotherapy. Combination of MMC and astaxanthin synergistically resulted in cytotoxicity and cell growth inhibition in NSCLC cells, accompanied with reduced phospho-AKT(Ser473) level and Rad51 expression. Overexpression of AKT-CA or Flag-tagged Rad51 reversed the astaxanthin and MMC-induced synergistic cytotoxicity. In contrast, pretreatment with LY294002 further decreased the cell viability in astaxanthin and MMC co-treated cells. In conclusion, astaxanthin enhances MMC-induced cytotoxicity by decreasing Rad51 expression and AKT activation. These findings may provide rationale to combine astaxanthin with MMC for the treatment of NSCLC.

Minocycline enhances mitomycin C-induced cytotoxicity through down-regulating ERK1/2-mediated Rad51 expression in human non-small cell lung cancer cells

Minocycline is a semisynthetic tetracycline derivative; it has anti-inflammatory and anti-cancer effects distinct from its antimicrobial function. However, the molecular mechanism of minocycline-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. Rad51 plays a central role in homologous recombination and high levels of Rad51 expression are observed in chemo- or radioresistant carcinomas. Our previous studies have shown that the MKK1/2-ERK1/2 signal pathway maintains the expression of Rad51 in NSCLC cells. In this study, minocycline treatment inhibited cell viability and proliferation of two NSCLC cells, A549 and H1975. Treatment with minocycline decreased Rad51 mRNA and protein levels through MKK1/2-ERK1/2 inactivation. Furthermore, expression of constitutively active MKK1 (MKK1-CA) vectors significantly rescued the decreased Rad51 protein and mRNA levels in minocycline-treated NSCLC cells. However, combined treatment with MKK1/2 inhibitor U0126 and minocycline further decreased the Rad51 expression and cell viability of NSCLC cells. Knocking down Rad51 expression by transfection with small interfering RNA of Rad51 enhanced the cytotoxicity and cell growth inhibition of minocycline. Mitomycin C (MMC) is typically used as a first or second line regimen to treat NSCLC. Compared to a single agent alone, MMC combined with minocycline resulted in cytotoxicity and cell growth inhibition synergistically in NSCLC cells, accompanied with reduced activation of phospho-ERK1/2, and reduced Rad51 protein levels. Overexpression of MKK1-CA or Flag-tagged Rad51 could reverse the minocycline and MMC-induced synergistic cytotoxicity. These findings may have implications for the rational design of future drug regimens incorporating minocycline and MMC for the treatment of NSCLC.

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

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

Pharmacogenomics of cisplatin sensitivity in non-small cell lung cancer

Cisplatin, a platinum-based chemotherapeutic drug, has been used for over 30 years in a wide variety of cancers with varying degrees of success. In particular, cisplatin has been used to treat late stage non-small cell lung cancer (NSCLC) as the standard of care. However, therapeutic outcomes vary from patient to patient. Considerable efforts have been invested to identify biomarkers that can be used to predict cisplatin sensitivity in NSCLC. Here we reviewed current evidence for cisplatin sensitivity biomarkers in NSCLC. We focused on several key pathways, including nucleotide excision repair, drug transport and metabolism. Both expression and germline DNA variation were evaluated in these key pathways. Current evidence suggests that cisplatin-based treatment could be improved by the use of these biomarkers.

Immunohistochemistry evaluation of biomarker expression in non-small cell lung cancer (Pharmacogenoscan study)

OBJECTIVES

Platinum-based chemotherapy regimens are the standard treatment of non-small cell lung cancer (NSCLC). In this study, our objective was to identify tumor tissue protein biomarkers that might predict a benefit from these treatments.

MATERIALS AND METHODS

The Pharmacogenoscan study prospectively included consecutive chemotherapy-naive NSCLC patients at any stage between 2005 and 2010 at six hospitals in the Rhône-Alpes-Auvergne region of France. Of the 537 patients in the full analysis set, 460 had a complete histological diagnosis. We used the tumor tissue samples for an immunohistochemical evaluation of eight biomarkers: ERCC1, BRCA1, p53, p27kip1, class III β-tubulin (TUBB3), Bax, Fas, and FasL. We looked for associations between these biomarkers and the disease control rate (DCR) after 2/3 cycles of platinum-based chemotherapy, progression-free survival (PFS), and overall survival (OS).

RESULTS

A tissue sample adequate for testing at least one biomarker was available for 289 patients. We found no significant association between biomarker expression levels and clinical or pathological variables; TUBB3 showed a trend toward higher expression in adenocarcinomas (P=0.005). For none of the biomarkers were significant associations found between expression level and DCR, PFS, or OS. TUBB3-negative and FasL-negative tumors showed associations of borderline significance with higher DCR.

CONCLUSION

In a large cohort of patients with predominantly advanced or metastatic NSCLC, none of eight tested immunohistochemical biomarkers predicted the chemotherapy response or survival. Our data indicate limited usefulness of protein biomarkers in metastatic NSCLC and a need for further research based on molecular signatures of greater complexity.

Expression of DNA translesion synthesis polymerase η in head and neck squamous cell cancer predicts resistance to gemcitabine and cisplatin-based chemotherapy

Purpose

The development of resistance against anticancer drugs has been a persistent clinical problem for the treatment of locally advanced malignancies in the head and neck mucosal derived squamous cell carcinoma (HNSCC). Recent evidence indicates that the DNA translesion synthesis (TLS) polymerase η (Pol η; hRad30a gene) reduces the effectiveness of gemcitabine/cisplatin. The goal of this study is to examine the relationship between the expression level of Pol η and the observed resistance against these chemotherapeutic agents in HNSCC, which is currently unknown.

Methods

Sixty-four mucosal derived squamous cell carcinomas of head and neck (HNSCC) from 1989 and 2007 at the City of Hope National Medical Center (Duarte, CA) were retrospectively analyzed. Pretreatment samples were immunostained with anti-Pol η antibody and the correlation between the expression level of Pol η and clinical outcomes were evaluated. Forty-nine cases treated with platinum (n=40) or gemcitabine (n=9) based chemotherapy were further examined for Pol η expression level for comparison with patient response to chemotherapy.

Results

The expression of Pol η was elevated in 67% of the head and neck tumor samples. Pol η expression level was significantly higher in grade 1 to grade 2 tumors (well to moderately differentiated). The overall benefit rate (complete response+ partial response) in patients treated with platinum and gemcitabine based chemotherapy was 79.5%, where low Pol η level was significantly associated with high complete response rate (p=0.03), although not associated with overall survival. Furthermore, no significant correlation was observed between Pol η expression level with gender, age, tobacco/alcohol history, tumor stage and metastatic status.

Conclusions

Our data suggest that Pol η expression may be a useful prediction marker for the effectiveness of platinum or gemcitabine based therapy for HNSCC.

ERCC1/BRCA1 expression and gene polymorphisms as prognostic and predictive factors in advanced NSCLC treated with or without cisplatin

Background:

The FAST was a factorial trial in first-line treatment of advanced non-small-cell lung cancer (NSCLC), addressing the role of replacing cisplatin with a non-platinum agent. The prognostic and predictive effect of ERCC1/BRCA1 expression and ERCC1/XPD/XRCC1–3 gene polymorphisms on outcomes of patients was examined.

Methods:

Patients were randomised to receive treatment with or without cisplatin. ERCC1/BRCA1 expression was determined by immunohistochemistry. ERCC1 (C8092A, C118T), XPD (Lys751Gln), XRCC1 (Arg399Gln) and XRCC3 (Thr241Met) gene polymorphisms were evaluated on tumour DNA by TaqMan allelic discrimination assay.

Results:

Tumour samples were available from 110 of 433 patients enrolled: 54.7% were ERCC1 positive and 51.4% were BRCA1 positive. Overall, ERCC1-negative patients had better response rate (P=0.004), progression-free survival (P=0.023) and overall survival (P=0.012) compared with positive ones, with no statistically significant treatment interaction. The BRCA1-positive patients showed numerically better outcomes, although not statistically significant, with no treatment interaction. Among DNA repair gene polymorphisms, only XRCC1 Gln/Gln genotype evidenced a potential prognostic role (P=0.036).

Conclusion:

This study confirms the prognostic role of ERCC1 expression and XRCC1 (Arg399Gln) polymorphism in advanced NSCLC treated with first-line chemotherapy. None of these biomarkers was shown to be a specific predictive factor of cisplatin efficacy.

DNA repair and cytotoxic drugs: the potential role of RAD51 in clinical outcome of non-small-cell lung cancer patients

Many of the cytotoxic drugs used in the treatment of non-small-cell lung carcinoma patients can interfere with DNA activity and the definition of an individual DNA repair profile could be a key strategy to achieve better response to chemotherapeutic treatment. Although DNA repair mechanisms are important factors in the prevention of carcinogenesis, these molecular pathways are also involved in therapy response. RAD51 is a crucial element in DNA repair by homologous recombination and has been shown to interfere with the prognosis of patients treated with chemoradiotherapy. There is increasing evidence that genetic polymorphisms in repair enzymes can influence DNA repair capacity and, consequently, affect chemotherapy efficacy. We conducted this review to show the possible influence of the RAD51 genetic variants in damage repair capacity and treatment response in non-small-cell lung carcinoma patients.

Correlation between BRCA1 expression and clinicopathological factors including brain metastases in patients with non-small-cell lung cancer

BACKGROUND

Previously identified as a breast and ovarian cancer susceptibility gene, BRCA1 has gained major scientific interest as a potential prognostic and/or predictive marker for various tumors, including non-small-cell lung cancer (NSCLC), the leading cause of cancer related mortality worldwide. BRCA1 plays a central role in DNA damage response (DDR. It undergoes phosphorylation by various DDR kinases at different serine residues, of which ser1524 is known to be specifically phosphorylated by ATM in response to genotoxic stress.

METHODS

We performed BRCA1 immunohistochemistry on several tissue microarrays (TMAs) of 113 early (I, II stage) and advanced (III, IV stage) NSCLCs, using MS110 antibody against the BRCA1 N-terminal and S1524 antibody against the phosphorylated form of BRCA1 protein at ser1524 (Abcam). Patients with III and IV stage disease were treated by adjuvant cisplatin-based chemotherapy. Staining results were correlated with overall survival (OS), disease free survival (DFS) and with the occurrence of brain metastases.

RESULTS

BRCA1 S1524 nuclear positivity was significantly correlated with longer OS and DFS in stage I and II patients (P<0.05), while OS and DFS were shorter in S1524 positive stage III and IV patients (P<0.05). No significant correlation was found with brain metastases.

CONCLUSION

The results show that BRCA1 phosphorylaton, at least in ser1524, differentiates the fate of early and advanced NSCLC as well as response to chemotherapy, but the underlying mechanisms are not completely understood. Detection of phosphorylated forms of BRCA1 might serve as a useful prognostic and predictive marker for patients with NSCLC.

Genetic polymorphism of XRCC1 Arg399Gln is associated with survival in non-small-cell lung cancer patients treated with gemcitabine/platinum

INTRODUCTION

Elevated DNA-repair capacity has been related to chemoresistance of platinum doublet chemotherapy in non-small-cell lung cancer (NSCLC). We evaluated whether single nucleotide polymorphisms of DN- repair genes excision repair cross-complementing group 1 (ERCC1), ERCC2, x-ray repair cross-complementing group 1 (XRCC1), XRCC3, and RRM1 associate with treatment outcome in NSCLC patients receiving gemcitabine plus platinum as their first-line chemotherapy.

METHODS

Genotyping for eight polymorphisms in five DNA-repair genes was performed with the GenomeLab nucleotide polymorphismstream Genotyping System in 62 advanced NSCLC patients in a training set and 45 patients in a validation set treated with gemcitabine/platinum.

RESULTS

In the training set, the wild-type genotype of XRCC1 Arg399Gln (G/G) was associated with decreased median overall survival (OS) (22 months, 95% confidence interval [CI], 10-34 months versus not reached, log-rank test, p = 0.005) than those carrying variant genotypes (G/A+A/A). In addition, there was a statistically significant longer median OS in patients carrying wild-type ERCC2 Asp312Asn genotype (G/G) (51 months, 95% CI, 19-82 months versus 10 months, log-rank test, p < 0.001) than those carrying heterozygous variant genotypes (G/A). In the multivariate Cox model, we found a significant effect of XRCC1 Arg399Gln (G/A+A/A versus G/G, hazard ratio [HR] 0.290; 95%CI, 0.12-0.705, p = 0.006) and ERCC2 Asp312Asn (G/A versus G/G, HR 14.04; 95% CI, 2.253-87.513, p = 0.005) polymorphisms on patients' OS. In the validation set, only XRCC1 399

CONCLUSIONS

Genetic polymorphism of XRCC1 Arg399Gln may be a candidate for contributing interindividual difference in the OS of gemcitabine/platinum-treated advanced NSCLC patients.

Molecular Markers with Predictive and Prognostic Relevance in Lung Cancer

Lung cancer accounts for the majority of cancer-related deaths worldwide of which non-small-cell lung carcinoma alone takes a toll of around 85%. Platinum-based therapy is the stronghold for lung cancer at present. The discovery of various molecular alterations that underlie lung cancer has contributed to the development of specifically targeted therapies employing specific mutation inhibitors. Targeted chemotherapy based on molecular profiling has shown great promise in lung cancer treatment. Various molecular markers with predictive and prognostic significance in lung cancer have evolved as a result of advanced research. Testing of EGFR and Kras mutations is now a common practice among community oncologists, and more recently, ALK rearrangements have been added to this group. This paper discusses various predictive and prognostic markers that are being investigated and have shown significant relevance which can be exploited for targeted treatment in lung cancer.

Emodin affects ERCC1 expression in breast cancer cells

Background

Multi-drug resistance to chemotherapeutic agents is a major cause of treatment failure in breast cancer. In this study, we investigated the effects of emodin on reversing the multi-drug resistance, examined the ERCC1 protein expression in breast cancer cell line, and explored the relationship between reversal of multi-drug resistance and ERCC1 protein expression.

Methods

MTT assay was conducted to test the cytotoxicity of adriamycin and cisplatin to MCF-7/Adr cells with and without emodin pretreatment, and Western blot was performed to examine the ERCC1 protein expression.

Results

MCF-7/Adr cells had 21-fold and 11-fold baseline resistances to adriamycin and cisplatin, respectively. When emodin was added to the cell culture at the concentration of 10 μg/ml, the drug resistance was reduced from 21 folds to 2.86 folds for adriamycin, and from 11 folds to 1.79 folds for cisplatin. MCF-7/Adr cells treated with two concentrations (10μg/mL and 20μg/mL) of emodin, after 2, 4, 6, 10 days, the trend of ERCC1 expression was gradually decreased and the reduction was more obvious comparatively at the concentration of 20μg/mL.

Conclusions

Emodin could reverse the multi-drug resistance in MCF-7/Adr cells and down-regulate ERCC1 protein expression.

[BRCA1: a new predictive genomic marker for chemotherapy and radiotherapy of non-small cell lung cancer]

Non-small cell lung cancer (NSCLC) is one of the most common malignant tumors worldwide. Chemotherapy and radiotherapy are the main methods in therapy of NSCLC. The identification and characterization of predictive markers of radio- and chemo-sensitivity will be beneficial with customized treatment of NSCLC patients. This article will review the evidence regarding breast cancer susceptibility gene 1 (BRCA1) as a new predictive marker for chemotherapy and radiotherapy of NSCLC.

[EGFR-dependent impact of indol-3-carbinol on radiosensitivity of lung cancer cells]

背景与目的

吲哚-3-甲醇（indole-3-carbinol, I3C）是十字花科蔬菜中一种主要的有效植物化学物质，且具有防癌和抗癌作用。本研究旨在观察I3C是否影响表皮生长因子受体（epidermal growth factor receptor, EGFR）表达水平不同的肺癌细胞放射敏感性。

方法

采用MTT和克隆形成实验方法分别检测肺癌细胞的生长和存活率；siRNA转染方法降低细胞中EGFR蛋白表达水平；Western blot和RT-PCR法分别测定EGFR蛋白和mRNA的表达。

结果

采用无明显毒副作用的5 μmol/L剂量的I3C预处理明显降低了EGFR表达阳性的人肺腺癌H1975和人肺鳞癌H226细胞对γ-射线照射的放射敏感性，而I3C对EGFR表达阴性的人肺鳞癌NIH-H520细胞的放射敏感性则影响非常小。Western blot结果显示I3C可以增加H1975和H226细胞中EGFR蛋白的表达水平和Y845位点磷酸化水平。EGFR siRNA降低了NIH-H1975细胞中EGFR蛋白的表达，增加了细胞的放射敏感性，并有效地降低和抑制了I3C导致的细胞耐辐射效应。

结论

我们的研究结果首次证实I3C可以通过调节EGFR表达和磷酸化水平从而影响肺癌细胞的放射治疗敏感性，提示EGFR可能是I3C影响肺癌放射治疗敏感性的重要靶蛋白。

The role of BRCA1 in non-small cell lung cancer

BACKGROUND

BRCA1 (Breast cancer 1) was previously identified as a breast and ovarian cancer susceptibility gene, but recently gained a major scientific interest as a prognostic and/or predictive marker for various tumors, including non-small cell lung cancer (NSCLC), which is the leading cause of cancer related mortality in the world. We aimed to review the role of BRCA1 in NSCLC based on currently available literature.

METHODS

We performed the literature search in Pubmed database, using key words: BRCA1, non small cell lung cancer, chemotherapy, drug resistance. Articles published in English were selected for review.

RESULTS

Research papers are mainly focused on BRCA1 mRNA expression studies in response to DNA damaging chemotherapy. Several articles about genetic and epigenetic changes of BRCA1 in NSCLC were also available.

CONCLUSIONS

BRCA1 is a multifunctional tumor supressor protein, which plays a key role in essential cellular processes and modulates the cellular response to cytotoxic chemotherapy. With the difference from breast and ovarian cancer, BRCA1 has no role in NSCLC cancerogenesis and mainly discussed as a promising genomic marker for customized chemotherapy in NSCLC patients.

Pre-treatment tumor expression of ERCC1 in women with advanced stage epithelial ovarian cancer is not predictive of clinical outcomes: a Gynecologic Oncology Group study

OBJECTIVE

Excision repair cross-complementation group 1 (ERCC1) is required for the repair of platinum-induced DNA damage. This study sought to assess the prognostic value of ERCC1 expression, measured by immunohistochemistry (IHC) using a highly specific antibody, in advanced epithelial ovarian cancer (EOC) patients treated with platinum-based chemotherapy.

METHODS

Formalin-fixed, paraffin-embedded tumors were collected from two GOG phase III trials (GOG-172 and GOG-182) of patients with stage III/IV EOC treated with platinum-based chemotherapy. ERCC1 was detected by (IHC) using FL297 polyclonal antibody and tumors were categorized as negative or positive, based on nuclear staining of tumor cells. ERCC1 genotyping was performed as previously reported. Associations between ERCC1 expression and clinical characteristics, platinum responsiveness, progression-free survival (PFS) or overall survival (OS) were evaluated.

RESULTS

Of 408 eligible patients, 27% had tumors that were ERCC1 positive. ERCC1 expression was not associated with clinical characteristics or platinum-responsiveness. Women with ERCC1-positive versus -negative tumors had similar median PFS (17.9 months versus 17.5 months, respectively, p=0.59), median OS (52.0 months versus 47.0 months, respectively, p=0.30), risk of disease progression (adjusted hazard ratio [HR]=0.90, 95% confidence interval (CI): 0.71-1.15, p=0.41), and risk of death (adjusted HR=0.81, 95% CI: 0.61-1.07, p=0.14). ERCC1 expression, as measured by IHC, was not associated with single nucleotide polymorphisms (SNPs), in codon 118 and C8092A, of the ERCC1 gene.

CONCLUSIONS

ERCC1 expression, measured by IHC in pre-treatment tumor specimens, using a highly specific antibody, has limited clinical value in patients with advanced EOC treated with platinum and taxane based chemotherapy.

Pre-treatment tumor expression of ERCC1 in women with advanced stage epithelial ovarian cancer is not predictive of clinical outcomes: a Gynecologic Oncology Group study

OBJECTIVE

Excision repair cross-complementation group 1 (ERCC1) is required for the repair of platinum-induced DNA damage. This study sought to assess the prognostic value of ERCC1 expression, measured by immunohistochemistry (IHC) using a highly specific antibody, in advanced epithelial ovarian cancer (EOC) patients treated with platinum-based chemotherapy.

METHODS

Formalin-fixed, paraffin-embedded tumors were collected from two GOG phase III trials (GOG-172 and GOG-182) of patients with stage III/IV EOC treated with platinum-based chemotherapy. ERCC1 was detected by (IHC) using FL297 polyclonal antibody and tumors were categorized as negative or positive, based on nuclear staining of tumor cells. ERCC1 genotyping was performed as previously reported. Associations between ERCC1 expression and clinical characteristics, platinum responsiveness, progression-free survival (PFS) or overall survival (OS) were evaluated.

RESULTS

Of 408 eligible patients, 27% had tumors that were ERCC1 positive. ERCC1 expression was not associated with clinical characteristics or platinum-responsiveness. Women with ERCC1-positive versus -negative tumors had similar median PFS (17.9 months versus 17.5 months, respectively, p=0.59), median OS (52.0 months versus 47.0 months, respectively, p=0.30), risk of disease progression (adjusted hazard ratio [HR]=0.90, 95% confidence interval (CI): 0.71-1.15, p=0.41), and risk of death (adjusted HR=0.81, 95% CI: 0.61-1.07, p=0.14). ERCC1 expression, as measured by IHC, was not associated with single nucleotide polymorphisms (SNPs), in codon 118 and C8092A, of the ERCC1 gene.

CONCLUSIONS

ERCC1 expression, measured by IHC in pre-treatment tumor specimens, using a highly specific antibody, has limited clinical value in patients with advanced EOC treated with platinum and taxane based chemotherapy.

A personalized life: biomarker monitoring from cradle to grave

Considering the holy grail of future medical treatment being personalized medicines, biomarker research will become more and more the focus for attention not only to develop new medical treatment regimes, based on changes in biomarker patterns, but also for nutritional advice to guarantee a lifelong optimized health condition. The current review gives an outline of how personalized medicine can become established for actual medical treatment using new biomarker concepts. Starting from the development of biomarker research using mainly immunological techniques, the review gives an overview about biomarkers of prediction evolved and focuses on new methodology for the identification of biomarkers using hyphenated analytical techniques like metabolomics and lipidomics. The actual use of multivariate statistical methods in combination with metabolomics and lipidomics is discussed not only for medical treatment but also for precautionary risk identification in human biomonitoring studies.

RT-PCR versus immunohistochemistry for correlation and quantification of ERCC1, BRCA1, TUBB3 and RRM1 in NSCLC

BACKGROUND

Customized chemotherapy is increasingly used in the management of patients with advanced non-small cell lung cancer (NSCLC). However, the most reliable methodology to determine biomarker status is neither fully elucidated nor agreed upon. Accordingly, we evaluated the predictive efficiency of qRT-PCR and immunohistochemical analysis (IHC) on excision cross complementation group 1 (ERCC1), breast cancer susceptibility gene 1 (BRCA1), ribonucleotide reductase subunit M1 (RRM1) and class III β-tubulin (TUBB3).

PATIENTS AND METHODS

IHC and qRT-PCR on ERCC1, BRCA1, RRM1 and TUBB3 were performed on surgically resected tissue samples from NSCLC-patients included in a randomized trial. The median values of the biomarker expression dichotomized the population and were correlated to clinical endpoints.

RESULTS

Representative tissue samples from 33 patients showed no significant correlations between mRNA and protein expression. Predictive impact was demonstrated for all four biomarkers, when assessed by IHC, and reached significance for overall survival in patients with ERCC1-negative (14.3 vs. 8.5 months, p=0.018) and TUBB3-negative (18.5 vs. 11.10, p=0.027) tumours, while this was not the case for qRT-PCR.

CONCLUSIONS

IHC discriminated more effectively than qRT-PCR across four NSCLC-relevant biomarkers. The findings are further supported by the demonstrated lack of correlation between transcript and protein.

Molecular predictors of response to chemotherapy in non-small cell lung cancer

Lung cancer is the leading cause of cancer-related mortality in the United States with 222,520 new cases and 157,300 deaths anticipated in 2010. The primary objective of any cancer treatment is to improve patient outcomes including overall survival and quality of life while minimizing treatment toxicity. As our knowledge of the molecular mechanisms involved in the pathogenesis of lung cancer evolves, improved methods of therapeutic selection may help clinicians better realize these goals. Such selection may be accomplished by examining biomarkers within patients' tumors that may provide prognostic information such as risk of recurrence in early stage disease or predict benefit from specific therapies regardless of disease stage. Three such biomarkers have emerged--excision repair cross-complementation group 1, the regulatory subunit of the ribonucleotide reductase enzyme, and thymidylate synthase--and are actively being evaluated in patients with non-small cell lung cancer. This review will focus on the role of these biomarkers as predictive and/or prognostic markers in the selection of chemotherapy regimens in non-small cell lung cancer patients.

Molecular analysis of DNA repair gene methylation and protein expression during chemical-induced rat lung carcinogenesis

A defective ratio between DNA damage and repair may result in the occurrence of a malignant phenotype. Previous studies have found that many genetic alterations in DNA repair genes occur frequently in lung cancer. However, the epigenetic mechanisms underlying this tumorigenesis are not clear. Herein, we have used a chemical-induced rat lung carcinogenesis model to study the evolution of methylation alterations of DNA repair genes BRCA1, ERCC1, XRCC1, and MLH1. Methylation-specific PCR and immunohistochemistry were used to analyze gene methylation status and protein expression during the progression of lung carcinogenesis. Promoter hypermethylation of BRCA1 was only detected in three samples of infiltrating carcinoma. CpG island hypermethylation of ERCC1, XRCC1, and MLH1 was found to increase gradually throughout lung carcinogenesis progression. Both the prevalence of at least one methylated gene and the average number of methylated genes were heightened in squamous metaplasia and dysplasia compared with normal tissue and hyperplasia, and was further increased in carcinoma in situ (CIS) and infiltrating carcinoma. Immunohistochemical analysis showed that BRCA1 and MLH1 protein expression decreased progressively during the stages of lung carcinogenesis, whereas ERCC1 and XRCC1 expression were only found in later stages. Although methylation levels were elevated for ERCC1 and XRCC1 during carcinogenesis, an inverse correlation with protein expression was found only for BRCA1 and MLH1. These results suggest that a continuous accumulation of DNA repair gene hypermethylation and the consequent protein alterations might be a vital molecular mechanism during the process of multistep chemical-induced rat lung carcinogenesis.

Tumor and host factors that may limit efficacy of chemotherapy in non-small cell and small cell lung cancer

While chemotherapy provides useful palliation, advanced lung cancer remains incurable since those tumors that are initially sensitive to therapy rapidly develop acquired resistance. Resistance may arise from impaired drug delivery, extracellular factors, decreased drug uptake into tumor cells, increased drug efflux, drug inactivation by detoxifying factors, decreased drug activation or binding to target, altered target, increased damage repair, tolerance of damage, decreased proapoptotic factors, increased antiapoptotic factors, or altered cell cycling or transcription factors. Factors for which there is now substantial clinical evidence of a link to small cell lung cancer (SCLC) resistance to chemotherapy include MRP (for platinum-based combination chemotherapy) and MDR1/P-gp (for non-platinum agents). SPECT MIBI and Tc-TF scanning appears to predict chemotherapy benefit in SCLC. In non-small cell lung cancer (NSCLC), the strongest clinical evidence is for taxane resistance with elevated expression or mutation of class III beta-tubulin (and possibly alpha tubulin), platinum resistance and expression of ERCC1 or BCRP, gemcitabine resistance and RRM1 expression, and resistance to several agents and COX-2 expression (although COX-2 inhibitors have had minimal impact on drug efficacy clinically). Tumors expressing high BRCA1 may have increased resistance to platinums but increased sensitivity to taxanes. Limited early clinical data suggest that chemotherapy resistance in NSCLC may also be increased with decreased expression of cyclin B1 or of Eg5, or with increased expression of ICAM, matrilysin, osteopontin, DDH, survivin, PCDGF, caveolin-1, p21WAF1/CIP1, or 14-3-3sigma, and that IGF-1R inhibitors may increase efficacy of chemotherapy, particularly in squamous cell carcinomas. Equivocal data (with some positive studies but other negative studies) suggest that NSCLC tumors with some EGFR mutations may have increased sensitivity to chemotherapy, while K-ras mutations and expression of GST-pi, RB or p27kip1 may possibly confer resistance. While limited clinical data suggest that p53 mutations are associated with resistance to platinum-based therapies in NSCLC, data on p53 IHC positivity are equivocal. To date, resistance-modulating strategies have generally not proven clinically useful in lung cancer, although small randomized trials suggest a modest benefit of verapamil and related agents in NSCLC.

[The clinical signifcance of expression of ERCC1 and PkCalpha in non-small cell lung cancer]

BACKGROUND AND OBJECTIVE

Excision repair cross-complementing 1 (Excision-Repair Cross-Complementing 1, ERCC1), an important member of the DNA repair gene family, plays a key role in nucleotide excision repair and apoptosis of tumor cells. Protein kinase C-alpha (Protein kinase C, PKCalpha), an isozyme in protein kinase C family, is an important signaling molecule in signal transduction pathways of tumors, which has been implicated in malignant transformation and proliferation. The aim of this study was to explore the clinical significance of ERCC1 and PKCalpha in non-small cell lung cancer (NSCLC).

METHODS

The expression of ERCC1 and PKCalpha were examined by immunohistochemistry (IHC) in the specimens of 51 cases of NSCLC patients tissue and 21 cases of paracancerous tissue. The relationship between detected data and patients' clinical parameters was analyzed by SPSS 13.0 software.

RESULTS

The positive expression rate of ERCC1 and PKCalpha in NSCLC tissues was significantly higher than paracancerous tissues (P < 0.05). Expression of ERCC1 was closely related to clinical stage and N stage. The positive rate of ERCC1 was higher in III+IV or N1+N2 stage patients compared with I+II or N0 stage (P = 0.011, P = 0.015). We also found that 5-year survival of negative group of ERCC1 was remarkably higher than that of positive group by chi2 test (P < 0.05). Expression of ERCC1 was positively correlative to PKCalpha by Spearman's correlation analysis (r = 0.425, P = 0.002) in NSCLC.

CONCLUSION

The results suggest ERCC1 and PKCalpha might be correlated with the development of NSCLC. ERCC1 might be related to prognosis of NSCLC. There might be existed a mechanism of coordination or regulation between ERCC1 and PKCalpha.

The platinum-based treatments for advanced non-small cell lung cancer, is low/negative ERCC1 expression better than high/positive ERCC1 expression? A meta-analysis

BACKGROUND

The predictive value of ERCC1 for prognosis and sensitivity to platinum-based chemotherapy in patients with non-small cell lung cancer (NSCLC) remains controversial. This meta-analysis was performed to provide an assessment of whether expression variations of ERCC1 are associated with objective response and median survival in patients with advanced NSCLC treated with platinum-based chemotherapy.

METHODS

We searched MEDLINE, EMBASE and CNKI for all eligible studies and conducted a meta-analysis of 12 studies (n=836 patients) that evaluated the correlation between ERCC1 levels (detected by immunohistochemistry or real-time reverse transcriptase PCR) and objective response or median survival in patients receiving platinum-based chemotherapy for advanced NSCLC. Pooled odds ratios (OR) for the objective response were calculated using the Mantel-Haenszel method. Pooled median ratios for median survival were calculated using the weighted sum of the log-ratio of median ratios from each individual study.

RESULTS

Among 836 tumors, ERCC1 expression was high/positive in 416 (49.8%) and low/negative in 420 (50.2%). Response to platinum-based chemotherapy was significantly higher in patients with ERCC1 low/negative expression (OR=0.48; 95% CI, 0.35-0.64; P<0.00001). Median survival time was significantly prolonged when ERCC1 low/negative expression was compared with ERCC1 high/positive expression (MR: 0.77; 95% CI, 0.47-1.07; P<0.00001).

CONCLUSIONS

Low/negative expression of ERCC1 was associated with higher objective response and median survival in advanced NSCLC patients treated with platinum-based chemotherapy. ERCC1 may be a suitable marker of prognosis and sensitivity to platinum-based chemotherapy in patients with advanced NSCLC.

Fine tuning chemotherapy to match BRCA1 status

Targeted cancer therapies have been primarily directed at inhibiting oncogenes that are overexpressed or constitutively active in tumors. It is thought that as the cell's circuitry gets re-wired by the constitutive activation of some pathways it becomes exquisitely dependent on this activity. Tumor cell death normally results from inhibiting constitutively active pathways. The dependence of tumor cells on the activity of these pathways has been called oncogene addiction. Approaches that aim to exploit loss of function, rather than gain of function changes have also become a powerful addition to our arsenal of cancer therapies. In particular, when tumors acquire mutations that disrupt pathways in the DNA damage response they rely on alternative pathways that can be targeted pharmacologically. Here we review the use of BRCA1 as a marker of response to therapy with a particular focus on the use of Cisplatin and PARP inhibitors. We also explore the use of BRCA1 as a marker of response to microtubule inhibitors and how all these approaches will bring us closer to the goal of personalized medicine in cancer treatment.

[The expression and prognostic significance of ERCC1 and GST-pi in lung cancer]

BACKGROUND AND OBJECTIVE

It has been known that the expression levels of ERCC1 and GST-pi were correlated with tumorigenesis and prognosis. The aim of this study is to investigate the relationship between expression levels of ERCC1 and GST-pi, and clinicopathologic parameters and survival in patients with lung cancer.

METHODS

The expression levels of ERCC1 and GST-pi were detected by immunohistochemical staining on tissue micro-array sections made of 148 cases of lung cancer and 7 cases of normal lung samples. The results were compared with relevant clinical and pathologic data.

RESULTS

Positive rates of ERCC1 and GST-pi were 36.2% and 73.6%, respectively. None of normal lung samples was positive staining. Positive expression of ERCC1 was significantly higher in group of non-small cell lung cancer (NSCLC), highly differentiated and the smokers less than 400 (P < 0.05), positive expression of GST-pi was significantly higher in group of non-smokers and NSCLC (P < 0.05). There were significant correlations between expression of ERCC1 and GST-pi (r = 0.253, P = 0.001). The 5 years survival rate was higher in positive expression of ERCC1. There was significant correlations between expression of ERCC1 and survival (P = 0.037). There was no significant correlations between expression of GST-pi and survival (P = 0.614). Multivariate analysis using Cox regression model showed that expression levels of ERCC1 and GST-pi were not the important independent prognostic factors for survival.

CONCLUSION

ERCC1 and GST-pi are aberrant highly expressed in NSCLC with positive correlation, which indicate they might act synergistically in tumorigenesis of NSCLC. The positive expression of ERCC1 have better survival and may have effect on prognosis.

Suppression of ERCC1 and Rad51 expression through ERK1/2 inactivation is essential in emodin-mediated cytotoxicity in human non-small cell lung cancer cells

Emodin, a tyrosine kinase inhibitor, is a natural anthraquinone derivative found in the roots and rhizomes of numerous plants. Emodin exhibits anticancer effects against a variety of cancer cells, including lung cancer cells. ERCC1 and Rad51 proteins are essential for nucleotide excision repair and homologous recombination, respectively. Furthermore, ERCC1 and Rad51 overexpression induces resistance to DNA-damaging agents that promote DNA double-strand breaks. Accordingly, the aim of this study was to determine the role of ERCC1 and Rad51 in emodin-mediated cytotoxicity in human non-small cell lung cancer (NSCLC) cells. Both ERCC1 and Rad51 protein levels as well as mRNA levels were decreased in four different NSCLC cell lines after exposure to emodin. These decreases correlated with the inactivation of the MKK1/2-ERK1/2 pathway. Moreover, cellular ERCC1 and Rad51 protein and mRNA levels were specifically inhibited by U0126, a MKK1/2 inhibitor. We found that transient transfection of human NSCLC cells with si-ERCC1 or si-Rad51 RNA and cotreatment with U0126 could enhance emodin-induced cytotoxicity. In contrast, overexpression of constitutively active MKK1/2 vectors (MKK1/2-CA) was shown to significantly recover reduced phospho-ERK1/2, ERCC1, and Rad51 protein levels and to rescue cell viability upon emodin treatment. These results demonstrate that activation of the MKK1/2-ERK1/2 pathway is the upstream signal regulating the expressions of ERCC1 and Rad51, which are suppressed by emodin to induce cytotoxicity in NSCLC cells.

Resistance gene expression determines the in vitro chemosensitivity of non-small cell lung cancer (NSCLC)

Background

NSCLC exhibits considerable heterogeneity in its sensitivity to chemotherapy and similar heterogeneity is noted in vitro in a variety of model systems. This study has tested the hypothesis that the molecular basis of the observed in vitro chemosensitivity of NSCLC lies within the known resistance mechanisms inherent to these patients' tumors.

Methods

The chemosensitivity of a series of 49 NSCLC tumors was assessed using the ATP-based tumor chemosensitivity assay (ATP-TCA) and compared with quantitative expression of resistance genes measured by RT-PCR in a Taqman Array™ following extraction of RNA from formalin-fixed paraffin-embedded (FFPE) tissue.

Results

There was considerable heterogeneity between tumors within the ATP-TCA, and while this showed no direct correlation with individual gene expression, there was strong correlation of multi-gene signatures for many of the single agents and combinations tested. For instance, docetaxel activity showed some dependence on the expression of drug pumps, while cisplatin activity showed some dependence on DNA repair enzyme expression. Activity of both drugs was influenced more strongly still by the expression of anti- and pro-apoptotic genes by the tumor for both docetaxel and cisplatin. The doublet combinations of cisplatin with gemcitabine and cisplatin with docetaxel showed gene expression signatures incorporating resistance mechanisms for both agents.

Conclusion

Genes predicted to be involved in known mechanisms drug sensitivity and resistance correlate well with in vitro chemosensitivity and may allow the definition of predictive signatures to guide individualized chemotherapy in lung cancer.

Can the status of the breast and ovarian cancer susceptibility gene 1 product (BRCA1) predict response to taxane-based cancer therapy?

Taxanes (paclitaxel and docetaxel) are currently used to treat ovarian, breast, lung, and head and neck cancers. Despite its clinical success taxane-based treatment could be significantly improved by identifying those patients whose tumors are more likely to present a clinical response. In this mini-review we discuss the accumulating evidence indicating that the breast and ovarian cancer susceptibility gene product BRCA1 mediates cellular response to taxanes. We review data from in vitro, animal, and clinical studies, and discuss them in context of response to therapy. We argue that levels of BRCA1 in tumors may provide a predictive marker for the response to treatment with taxanes. In addition, the study of the role of BRCA1 in the mechanism of action of taxanes might reveal alternative approaches to avoid resistance.

The prognostic significance of ERCC1, BRCA1, XRCC1, and betaIII-tubulin expression in patients with non-small cell lung cancer treated by platinum- and taxane-based neoadjuvant chemotherapy and surgical resection

OBJECTIVES

The DNA repair pathway and isotype composition of beta-tubulin are known to be associated with resistance to platinum- and taxane-based chemotherapy, respectively. The aim of this study was to identify the clinical significance of excision repair cross-complementation 1 (ERCC1), breast cancer susceptibility gene 1 (BRCA1), X-ray repair cross-complementation 1 (XRCC1) and betaIII-tubulin on the chemotherapy response and overall survival in patients with non-small cell lung cancer (NSCLC) who received neoadjuvant chemotherapy.

METHODS

Protein expression profiles were evaluated by immunohistochemistry on surgical specimens of 82 NSCLC patients who underwent platinum- and taxane-based neoadjuvant chemotherapy. The expression levels of proteins were measured semi-quantitatively and the correlation with tumor responses, pathologic cell death rate and survival were evaluated.

RESULTS

There were 73 (89.0%) clinical stage III patients. Lobectomy, bilobectomy, and pneumonectomy were performed in 54 (65.0%), 11 (13.4%), and 17 (20.7%) patients, respectively. There was no correlation between clinical response and protein expression. The expression levels of ERCC1, BRCA1, and XRCC1 increased proportionally to the cell death rate (p<0.05); however, betaIII-tubulin expression did not correlate with cell viability. Multivariate analysis demonstrated that early pathologic stage, adjuvant chemotherapy, high ERCC1 and low betaIII-tubulin expression were good prognostic factors for overall survival (p<0.05).

CONCLUSIONS

The inverse correlation between DNA repair proteins and cell viability suggests that these protein expression levels can be markers for chemotherapy responsiveness. However, only ERCC1 and betaIII-tubulin were prognostic factors after platinum- and taxane-based neoadjuvant chemotherapy following surgical resection.

Epigenetics of multiple myeloma after treatment with cytostatics and gamma radiation

Genetic and epigenetic changes in multiple myeloma (MM) correlate with the stage of the disease. Therefore, we investigated how cytostatics and gamma radiation influence MM-associated histone modifications. ChIP-PCR and ChIP-on-chip technologies were used to quantify H3K9 acetylation and H3K9 dimethylation at select loci in MM patients, lymphoblastoid ARH-77, and myeloma MOLP-8 cells. Genome-wide analysis revealed that the cytostatic, melphalan, increased H3K9 acetylation at multiple gene promoters in ARH-77 cells. Melphalan and gamma radiation also influenced histone modification of prognostically important c-myc and CCND1 genes in ARH-77 and MOLP-8 cells. Moreover, H3K9 acetylation at c-myc and CCND1 promoters was increased in individual MM patients after melphalan treatment. Western blotting revealed that these effects were accompanied by changes in c-MYC and cyclin D1 protein levels. Taken together, we showed that cytostatics significantly alter histone modification of tumor-related genes which is indispensable for understanding cancer therapies.

Pharmacogenomics of gemcitabine in non-small-cell lung cancer and other solid tumors

The validation of predictive biomarkers to tailor chemotherapy is a key issue in the development of effective treatment modalities against cancer. Examples of how genetics might affect drug response are offered by gemcitabine. A substantial number of potential biomarkers for sensitivity or resistance to gemcitabine have been proposed, including ribonucleotide reductase and cytidine deaminase polymorphisms, human equilibrative transporter-1 and ribonucleotide reductase gene-expression and AKT phosphorylation status. These markers displayed a significant relationship with disease response to the drug; however, their robustness needs to be evaluated within prospective studies. Moreover, recent trials of customized chemotherapy based on genetic markers have been carried out in non-small-cell lung cancer and promising pharmacogenetic determinants are gaining momentum, including BRCA1 and ERCC1. Hopefully, biomarkers to select patients most likely to respond to gemcitabine will be validated in the near future.