RRM1 and ERCC1 expression in peripheral blood versus tumor tissue in gemcitabine/carboplatin-treated advanced non-small cell lung cancer

Double-staining Immunohistochemistry Reveals in Malignant Pleural Mesothelioma the Coexpression of ERCC1 and RRM1 as a Frequent Biological Event Related to Poorer Survival

Malignant pleural mesothelioma (MPM) is a rare cancer with a poor prognosis. To date, standard MPM therapy is still limited to surgery, radiotherapy, and chemotherapy, including pemetrexed and platinum compounds. The main mechanisms of platinum resistance are associated with DNA repair pathways. Excision repair cross-complementing group 1 (ERCC1) and ribonucleotide reductase subunit M1 (RRM1) are important components of the DNA repair, considered as prognostic and predictive biomarkers in various cancer types. The main goal of the present study was to investigate the ERCC1 and RRM1 expression and their potential impact on outcome in this tumor. A series of 73 MPM, mainly treated with a platin-based regimen, was collected and the immunohistochemistry tests were performed to assess ERCC1 and RRM1 expression. In addition, a multiplex immunohistochemistry has been validated to detect simultaneously the 2 proteins on the same slide. In our series, 36 of 73 cases showed ERCC1 expression and 55 of 73 showed RRM1 expression. The double immunohistochemical staining showed the coexpression of ERCC1/RRM1 in 34 of 73 cases. A significant association between ERCC1 and RRM1 expression was observed in our series (P<0.05). Patients with ERCC1/RRM1 coexpression experienced shorter median overall survival (6.6 vs. 13.8 mo, log-rank=7688; P=0.006). Our results suggest that the coexpression of ERCC1/RRM1 could define a group of MPM patients with the worst prognosis who should need likely alternative treatment. In conclusion, we propose the putative usefulness of ERCC1/RRM1 coexpression as prognostic biomarkers for overall survival in MPM.

RRM1 expression and the clinicopathological characteristics of patients with non-small cell lung cancer treated with gemcitabine

Background

The usefulness of ribonucleotide reductase catalytic subunit M1 (RRM1) for predicting the therapeutic effects of gemcitabine-containing chemotherapy in patients with non-small cell lung cancer (NSCLC) remains controversial. RRM1-positive patients show unique clinicopathological features.

Methods

Here, we performed a meta-analysis to systematically evaluate the relationship between RRM1 expression and the clinicopathological characteristics of NSCLC patients treated with gemcitabine-containing regimens. A comprehensive electronic and manual search was performed to identify relevant articles. The pooled relative risk (RR) and 95% CI were used to estimate the relation between the clinicopathological characteristics of NSCLC patients and RRM1 expression.

Results

The study included 31 observational studies and 3,667 patients. The analysis showed no significant association between RRM1 expression and pathological type, stage, and smoking status; however, RRM1 positivity was significantly lower in women than in men (43.0% vs 51.7%, RR=0.84, 95% CI: 0.74-0.94, P=0.004).

Conclusion

The present pooled analyses demonstrated that RRM1 positivity in women with advanced NSCLC was associated with a higher rate of response to gemcitabine-containing regimens. Immunohistochemistry may be valuable to prescreen for RRM1 expression in clinical practice, whereas PCR can be routinely used as a verification method. These findings will help design suitable molecular-targeted therapies for NSCLC.

Prognostic value of ribonucleotide reductase subunit M1 (RRM1) in non-small cell lung cancer: A meta-analysis

BACKGROUND

Ribonucleotide reductase subunit 1 (RRM1) is a potential prognostic factor for non-small cell lung cancer (NSCLC). This study evaluates prognostic value of RRM1 in NSCLC patients by meta-analyzing outcomes reported in literature.

METHOD

Data were acquired from research articles retrieved after literature search in online databases. Random effects meta-analyses were conducted by pooling hazard ratios (HR). Meta-analyses of standardized mean differences (SMD) were used to evaluate overall survival (OS) and progression-free survival (PFS) between low and high RRM1 expression groups. Metaregression analyses were conducted to evaluate the factors that could affect prognostic relationship of RRM1 with treatment and survival outcomes.

RESULTS

23 studies (3148 patients) were included. RRM1 expression was not meaningfully associated with prognosis of NSCLC even when the reference (HR = 1) was either low RRM1 expression (0.918 [95% CI 0.833, 1.003]) or high RRM1 expression (0.834 [0.625, 1.043]). OS was significantly longer in low RRM1 expression group compared to high RRM1 expression group (SMD 0.73 [0.36, 1.09]; P < 0.0001). PFS was not significantly different between low and high RRM1 expression groups (SMD 0.08 [-0.29, 0.45]; p = 0.68). Age was inversely associated with HR (p = 0.001) even when reference was low RRMI (p = 0.027) or high RRM1 (p = 0.006). Age was positively associated with OS in both low and high RRM1 groups.

CONCLUSION

In meta-analysis of studies which used gemcitabine-based therapies, higher RRM1 expression is found to associated with shorter OS but not PFS. HR depicting relationship between RRM1 expression and OS/PFS/treatment response could not demonstrate a prognostic role of RRM1 in NSCLC patients.

Microdose-Induced Drug-DNA Adducts as Biomarkers of Chemotherapy Resistance in Humans and Mice

We report progress on predicting tumor response to platinum-based chemotherapy with a novel mass spectrometry approach. Fourteen bladder cancer patients were administered one diagnostic microdose each of [¹⁴C]carboplatin (1% of the therapeutic dose). Carboplatin-DNA adducts were quantified by accelerator mass spectrometry in blood and tumor samples collected within 24 hours, and compared with subsequent chemotherapy response. Patients with the highest adduct levels were responders, but not all responders had high adduct levels. Four patient-derived bladder cancer xenograft mouse models were used to test the possibility that another drug in the regimen could cause a response. The mice were dosed with [¹⁴C]carboplatin or [¹⁴C]gemcitabine and the resulting drug-DNA adduct levels were compared with tumor response to chemotherapy. At least one of the drugs had to induce high drug-DNA adduct levels or create a synergistic increase in overall adducts to prompt a corresponding therapeutic response, demonstrating proof-of-principle for drug-DNA adducts as predictive biomarkers. Mol Cancer Ther; 16(2); 376-87. ©2016 AACR.

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.

The Effects of HSP27 on Gemcitabine-Resistant Pancreatic Cancer Cell Line Through Snail

OBJECTIVES

To evaluate the regulation mechanism of heat shock protein 27 (HSP27) on gemcitabine (GEM) resistance of pancreatic cancer cell.

METHODS

The expression vectors pEGFP-C1-HSP27 and the vectors of MicroRNA targeting Snail were introduced into GEM-sensitive pancreatic cancer SW1990 cells, and the vectors of small hairpin RNA targeting HSP27 were transfected into SW1990 and GEM-resistant SW1990/GEM cells. The expressions of HSP27, p-HSP27 (Ser82), Snail, ERCC1, and E-cadherin were evaluated by Western blotting. The sensitivity of transfected cells to GEM was detected by CCK-8 assay and Annexin V-FITC apoptosis assay.

RESULTS

As compared to SW1990, SW1990/GEM showed significantly increased expressions of HSP27, p-HSP27, Snail and ERCC1 with decreased expression of E-cadherin. By increasing HSP27 expression, we found increase of Snail and ERCC1 with reduction of E-cadherin expressions, while reduction of HSP27 expression caused reduction of Snail and ERCC1 but increase of E-cadherin expressions. Downregulation of Snail resulted in the reduction of ERCC1 expression and increase of E-cadherin. Furthermore, downregulation of HSP27 or snail caused increased GEM sensitivity of pancreatic cancer cells, and upregulation of HSP27 showed the opposite results.

CONCLUSIONS

There is an inverse correlation between HSP27 expression and GEM sensitivity of SW1990 cells, which might be realized by regulating E-cadherin and ERCC1 expressions through Snail.

Association of GSTP1 and RRM1 Polymorphisms with the Response and Toxicity of Gemcitabine-cisplatin Combination Chemotherapy in Chinese Patients with Non-small Cell Lung Cancer

BACKGROUND

Previous studies showed that genetic polymorphisms of glutathione S-transferase P1 (GSTP1) were involved in glutathione metabolism and genetic polymorphisms of ribonucleotide reductase (RRM1) were correlated with DNA synthesis. Here we explored the effects of these polymorphisms on the chemosensitivity and clinical outcome in Chinese non-small cell lung cancer (NSCLC) patients treated with gemcitabine-cisplatin regimens.

MATERIALS AND METHODS

DNA sequencing was used to evaluate genetic polymorphisms of GSTP1 Ile105Val and RRM1 C37A-T524C in 47 NSCLC patients treated with gemcitabine-cisplatin regimens. Clinical response was evaluated according to RECIST criteria after 2 cycles of chemotherapy and toxicity was assessed by 1979 WHO criteria (acute and subacute toxicity graduation criteria in chemotherapeutic agents).

RESULTS

There was no statistical significance between sensitive and non-sensitive groups regarding the genotype frequency distribution of GSTP1 Ile105Val polymorphism (p>0.05). But for RRM1 C37A-T524C genotype, sensitive group had higher proportion of high effective genotype than non-sensitive group (p=0.009). And according to the joint detection of GSTP1 Ile105Val and RRM1 C37A-T524C polymorphisms, the proportion of type A (A/A+high effective genotype) was significantly higher in sensitive group than in non-sensitive group (p=0.009). Toxicity showed no correlation with the genotypes between two groups (p>0.05).

CONCLUSIONS

Compared with single detection of genetic polymorphisms of GSTP1 Ile105Val or RRM1 C37A-T524C, joint detection of both may be more helpful for patients with NSCLC to receive gemcitabine-cisplatin regimens as the first-line chemotherapy. Especially, genetic polymorphism of RRM1 is more likely to be used as an important biomarker to predict the response and toxicity of gemcitabine-cisplatin combination chemotherapy in NSCLC.

Prognostic and predictive biomarkers in early stage non-small cell lung cancer: tumor based approaches including gene signatures

In early stage non-small cell lung cancer (NSCLC) large randomized trials have demonstrated that in patients with radically resected disease adjuvant chemotherapy improves 5-year survival rates. However, a customization of systemic treatment is needed to avoid treatments in patients cured by surgery alone or to justify the use of adjuvant chemotherapy in high risk patients, including those in stage IA. Recently, the possibility of identifying prognostic and predictive factors related to the genetic signatures of the tumor that could affect adjuvant and neo-adjuvant treatment choices for resectable non-small cell lung cancer (NSCLC) has been of interest. This review summarizes the current status and future opportunities for clinical application of genotyping and genomic tests in early NSCLC.

Prognostic significance of BRCA1, ERCC1, RRM1, and RRM2 in patients with advanced non-small cell lung cancer receiving chemotherapy

The aim of this study was to examine the prognostic value of breast cancer susceptibility gene 1 (BRCA1), excision repair cross-complementation 1 (ERCC1), ribonucleotide reductase subunit M1 (RRM1), and ribonucleotide reductase subunit M2 (RRM2) in patients with advanced non-small cell lung cancer (NSCLC) who received platinum-based chemotherapy. A total of 214 patients with histologically or cytologically confirmed advanced NSCLC were enrolled in this study. The relative complementary DNA (cDNA) quantification for BRCA1, ERCC1, RRM1, and RRM2 was conducted using a fluorescence-based, real-time detection method, and β-actin was used as a reference gene. A strong correlation was observed between ERCC1 and RRM1 messenger RNA (mRNA) levels (P = 0.0385). There were inverse significant correlations between BRCA1 and ERCC1 (P < 0.0001) or RRM1 (P < 0.0001) mRNA levels. As BRCA1 levels increased, the probability of response increased (odds ratio [OR] = 0.49; P < 0.001) and the risk of progression (hazard ratio [HR] = 1.52; P = 0.034) and death (HR = 1.45; P = 0.024) decreased. As ERCC1, RRM1, and RRM2 levels increased, the probability of response decreased (ERCC1, OR = 0.42, P < 0.001; RRM1, OR = 0.85, P = 0.083; RRM2, OR = 0.42, P = 0.005) and the risk of progression (ERCC1, HR = 1.59, P = 0.002; RRM1, HR = 1.48, P = 0.039; RRM2, HR = 1.49, P = 0.041) and death (ERCC1, HR = 1.62, P = 0.008; RRM1, HR = 1.52, P = 0.023; RRM2, HR = 1.48, P = 0.017) increased. At multivariate analysis, low expression of ERCC1 was shown to be an independent predictive factor for response to chemotherapy (P = 0.018), time to progression (P = 0.025), and overall survival (P = 0.038). Furthermore, concomitant low expression levels of ERCC1, RRM1, and RRM2 and the high expression level of BRCA1 were predictive of a better outcome (P = 0.014). This study suggests that the efficacy of platinum-based chemotherapy can be improved when customized according to the mRNA expression of BRCA1, ERCC1, RRM1, and RRM2.

ERCC1 and BRCA1 mRNA expression predicts the clinical outcome of non-small cell lung cancer receiving platinum-based chemotherapy

Objective: We conducted a perspective study to investigate the association between mRNA expression quantities of ERCC1, BRCA1, RRM1 and RRM2 and response to chemotherapy and clinical outcome of advance Non-Small Cell Lung Cancer.(NSCLC).

Methods: Two hundred eight patients who were diagnosed as advanced stage NSCLC were included in our study. A fluorescence-based and real-time detection method was used to determine the relative cDNA quantification for ERCC1, BRCA1, RRM1 and RRM2, and β-actin was used as the reference gene.

Results: The median expression levels of ERCC1, BRCA1, RRM1 and RRM2 mRNA were 0.67±0.17, 0.095±0.012, 0.24±0.17 and 2.45±0.32, respectively. Our study found that the low ERCC1 (OR=1.82, 95% CI=1.01-3.20) and Low BRCA1 (OR=2.53, 95%CI=1.38-4.64) mRNA expression was more likely to response to chemotherapy when compared with high expression, respectively. Multivariate Cox regression analysis indicated that patients with low mRNA expression of ERCC1 and BRCA1 attained 0.43 (OR=0.43, 95%CI=0.27-0.89) and 0.37 (OR=0.37, 95%CI=0.22-0.66) fold risk of death from NSCLC. However, we found RMM1 and RRM2 mRNA expression could not influence the response to chemotherapy and clinical outcome of NSCLC.

Conclusion: ERCC1 and BRCA1 mRNA expression could be important predictive markers for individualized platinum-based chemotherapy for NSCLC patients.

Opportunities for translation: targeting DNA repair pathways in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) remains one of the poorest prognosis neoplasms. It is typified by high levels of genomic aberrations and copy-number variation, intra-tumoural heterogeneity and resistance to conventional chemotherapy. Improved therapeutic options, ideally targeted against cancer-specific biological mechanisms, are urgently needed. Although induction of DNA damage and/or modulation of DNA damage response pathways are associated with the activity of a number of conventional PDAC chemotherapies, the effectiveness of this approach in the treatment of PDAC has not been comprehensively reviewed. Here, we review chemotherapeutic agents that have shown anti-cancer activity in PDAC and whose mechanisms of action involve modulation of DNA repair pathways. In addition, we highlight novel potential targets within these pathways based on the emerging understanding of PDAC biology and their exploitation as targets in other cancers.

Expression levels of ERCC1 and RRM1 mRNA and clinical outcome of advanced non-small cell lung cancer

Objective: We conducted a study to understand the genetic effect of ERCC1 and RRM1 on the chemotherapy response and clinical outcome of Non-Small Cell Lung Cancer (NSCLC).

Methods: The relative cDNA quantification for ERCC1 and RRM1 was conducted using a fluorescence-based real-time detection method among 294 NSCLC patients.

Results: Compared with the internal reference gene β-action, the median levels of ERCC1 and RRM1 expression were 2.43×10^-2 and 0.11×10^-2, respectively. Our study showed response to platinum-containing regimen chemotherapy was high in those with high ERCC1 expression, and the OR (95% CI) were 1.73(1.06-2.81). An apparently high response to chemotherapy was decreased when patients were carrying both high expression of ERCC1 and RRM1, with OR (95% CI) of 2.57(1.21-4.90). Patients with high expression of ERCC1 were associated with a longer OS by multivariate Cox proportional hazards model. Moreover, those carrying both high levels of ERCC1 and RRM1 were seem to have a longer OS when compared with those with low expression (HR=0.31, 95% CI=0.13-0.62 for OS).

Conclusion: This observation could be used in personalized chemotherapy, increase the response rate and prolonged survival time, and could encourage to explore the predictive value of other genes.

Ribonucleotide reductase large subunit M1 predicts poor survival due to modulation of proliferative and invasive ability of gastric cancer

OBJECTIVES

We aimed to investigate the prognostic value of RRM1 in GC patients.

METHODS

A total of assessable 389 GC patients with clinicopathological and survival information were enrolled from City of Hope (COH, n = 67) and Zhejiang University (ZJU, n = 322). RRM1 protein expression was determined by immunohistochemistry on FFPE tissue samples. Kaplan-Meier and Cox analyses were used to measure survival. Ras/Raf activity and invasion assays were used to evaluate the role of RRM1 in GC cell lines.

RESULTS

In vitro experiments demonstrated RRM1 activated Ras/Raf/MAPK signal transduction and promoted GC cell proliferation. Meanwhile, RRM1 expression was significantly associated with lymph node involvement, tumor size, Ki67 expression, histological subtype and histological grade in the GC tissue samples (p<0.05). Kaplan-Meier analysis illustrated that high RRM1 expression predicted poor survival in GC patients in the COH and ZJU cohorts (log-rank p<0.01). In multivariate Cox analysis, the hazard ratios of RRM1 for overall survival were 2.55 (95% CI 1.27-5.15) and 1.51 (95% CI 1.07-2.13) in the COH and ZJU sets, respectively. In particular, RRM1 specifically predicted the outcome of advanced GCs with poor differentiation and high proliferative ability. Furthermore, inhibition of RRM1 by siRNA significantly reduced the dNTP pool, Ras/Raf and MMP-9 activities and the levels of p-MEK, p-ERK and NF-κB, resulting in growth retardation and reduced invasion in AGS and NCI-N87 cells.

CONCLUSIONS

RRM1 overexpression predicts poor survival in GC patients with advanced TNM stage. RRM1 could potentially serve as prognostic biomarker and therapeutic target for GCs.

Just getting into cells is not enough: mechanisms underlying 4-(N)-stearoyl gemcitabine solid lipid nanoparticle's ability to overcome gemcitabine resistance caused by RRM1 overexpression

Gemcitabine is a deoxycytidine analog that is widely used in the chemotherapy of many solid tumors. However, acquired tumor cell resistance often limits its use. Previously, we discovered that 4-(N)-stearoyl gemcitabine solid lipid nanoparticles (4-(N)-GemC18-SLNs) can overcome multiple acquired gemcitabine resistance mechanisms, including RRM1 overexpression. The present study was designed to elucidate the mechanisms underlying the 4-(N)-GemC18-SLNs' ability to overcome gemcitabine resistance. The 4-(N)-GemC18 in the 4-(N)-GemC18-SLNs entered tumor cells due to clathrin-mediated endocytosis of the 4-(N)-GemC18-SLNs into the lysosomes of the cells, whereas the 4-(N)-GemC18 alone in solution entered cells by diffusion. We substantiated that it is the way the 4-(N)-GemC18-SLNs deliver the 4-(N)-GemC18 into tumor cells that allows the gemcitabine hydrolyzed from the 4-(N)-GemC18 to be more efficiently converted into its active metabolite, gemcitabine triphosphate (dFdCTP), and thus more potent against gemcitabine-resistant tumor cells than 4-(N)-GemC18 or gemcitabine alone. Moreover, we also showed that the RRM1-overexpressing tumor cells were also cross-resistant to cytarabine, another nucleoside analog commonly used in cancer therapy, and 4-(N)-stearoyl cytarabine carried by solid lipid nanoparticles can also overcome the resistance. Therefore, formulating the long-chain fatty acid amide derivatives of nucleoside analogs into solid lipid nanoparticles may represent a platform technology to increase the antitumor activity of the nucleoside analogs and to overcome tumor cell resistance to them.

ERCC1 and RRM1: ready for prime time?

The quest for markers of sensitivity to cytotoxic agents has been ongoing for decades. In non-small-cell lung cancer, platinum compounds represent the cornerstone of systemic therapy. They target DNA and induce damage that cancer cells struggle to overcome. Somatic excision repair cross-complementing rodent repair deficiency, complementation group 1 (ERCC1), and ribonucleotide reductase M1 (RRM1) expression levels have been extensively explored as markers of DNA repair capacity in tumor cells. Although low ERCC1 and/or RRM1 expression is generally associated with sensitivity to platinum, the results published in retrospective and prospective studies are not always consistent. Against this background, we will examine in this review the function of these two biomarkers as well as the tools available for their assessment and the associated technical issues. Their prognostic and predictive values will be summarized and considered in terms of customizing systemic therapy according to biomarker (ERCC1 and RRM1) expression levels. We will also discuss why the use of both markers should at this point be restricted to clinical research and underline that functional readouts of DNA repair will help boost future strategies for biomarker discovery in the field.