Dataset Information

Thymidylate synthase and folyl-polyglutamate synthase are not clinically useful markers of response to pemetrexed in patients with malignant pleural mesothelioma.

ABSTRACT:

Purpose

Thymidylate synthase (TS) is a potential predictor of outcome after pemetrexed (Pem) in patients with malignant pleural mesothelioma (MPM), and assays measuring TS levels are commercially marketed. The goal of this study was to further evaluate the value of TS and to study another potential biomarker of response, the enzyme, folyl-polyglutamate synthase (FPGS), which activates Pem intracellularly.

Methods

Levels of TS and FPGS were semi-quantitatively determined immunohistochemically using H-scores on tissue samples from 85 MPM patients receiving Pem as primary therapy. H-score was correlated with radiographic disease control rate (DCR), time to progression (TTP) and overall survival (OS). In addition, expression levels of TS and FPGS in MPM cell lines were determined using immunoblotting and correlated with their sensitivity to Pem-induced cell death.

Results

H-scores from patients with disease control versus progressive disease showed extensive overlap. There were no significant correlations of DCR, TTP, or OS to either TS levels (p = 0.73, 0.93, and 0.59, respectively), FPGS levels (p = 0.95, 0.77, and 0.43, respectively) or the ratio of FPGS/TS using the median scores of each test as cutoffs. There was no correlation between TS or FPGS expression and chemosensitivity of mesothelioma cells to Pem in vitro.

Conclusions

Although previous retrospective data suggest that TS and FPGS expression might be potential markers of Pem efficacy in MPM, our data indicate these markers lack sufficient predictive value in individual patients and should not be used to guide therapeutic decisions in the absence of prospective studies.

SUBMITTER: Lustgarten DE

PROVIDER: S-EPMC3601580 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature

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Publications

Thymidylate synthase and folyl-polyglutamate synthase are not clinically useful markers of response to pemetrexed in patients with malignant pleural mesothelioma.

Lustgarten Daniel E Schwed DE Deshpande Charuhas C Aggarwal Charu C Wang Liang-Chuan LC Saloura Vassiliki V Vachani Anil A Wang Li-Ping LP Litzky Leslie L Feldman Michael M Creaney Jeanette J Nowak Anna K AK Langer Corey C Inghilleri Simona S Stella Giulia G Albelda Steven M SM

Journal of thoracic oncology : official publication of the International Association for the Study of Lung Cancer 20130401 4

<h4>Purpose</h4>Thymidylate synthase (TS) is a potential predictor of outcome after pemetrexed (Pem) in patients with malignant pleural mesothelioma (MPM), and assays measuring TS levels are commercially marketed. The goal of this study was to further evaluate the value of TS and to study another potential biomarker of response, the enzyme, folyl-polyglutamate synthase (FPGS), which activates Pem intracellularly.<h4>Methods</h4>Levels of TS and FPGS were semi-quantitatively determined immunohist ...[more]

PMID: 23486267

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Project description:PurposeMalignant pleural mesothelioma (MPM) is an aggressive tumor characterized by poor prognosis. Its incidence is steadily increasing due to widespread asbestos exposure. There is still no effective therapy for MPM. Pemetrexed (Pe) is one of the few chemotherapeutic agents approved for advanced-stage disease, although the objective response to the drug is limited. The use of gold nanoparticles (GNPs) as a drug delivery system promises several advantages, including specific targeting of malignant cells, with increased intracellular drug accumulation and reduced systemic toxicity, and, in the case of MPM, direct treatment administration into the pleural space. This study aims at exploring CD146 as a potential MPM cell-specific target for engineered Pe-loaded GNPs and to assess their effectiveness in inhibiting MPM cell line growth.MethodsMPM cell lines and primary cultures obtained by pleural effusions from MPM patients were assayed for CD146 expression by flow cytometry. Internalization by MPM cell lines of fluorescent dye-marked GNPs decorated with a monoclonal anti CD146 coated GNPs (GNP-HC) was proven by confocal microscopy. The effects of anti CD146 coated GNPs loaded with Pe (GNP-HCPe) on MPM cell lines were evaluated by cell cycle (flow cytometry), viability (MTT test), clonogenic capacity (soft agar assay), ROS production (electric paramagnetic resonance), motility (wound healing assay), and apoptosis (flow cytometry).ResultsGNP-HC were selectively uptaken by MPM cells within 1 hour. MPM cell lines were blocked in the S cell cycle phase in the presence of GNP-HCPe. Both cell viability and motility were significantly affected by nanoparticle treatment compared to Pe. Apoptotic rate and ROS production were significantly higher in the presence of nanoparticles. Clonogenic capacity was completely inhibited following nanoparticle internalization.ConclusionGNP-HCPe treatment displays in vitro antineoplastic action and is more effective than Pe alone in inhibiting MPM cell line malignant phenotype. The innovative use of specifically targeted GNPs opens the perspective of local intrapleural administration to avoid normal cell toxicity and enhance chemotherapy efficacy.

Project description:INTRODUCTION:A combination of pemetrexed and cisplatin has been shown to improve the outcome in patients with malignant pleural mesothelioma (MPM), however, there is a great heterogeneity in treatment response among patients. The aim of our study was to evaluate the influence of polymorphisms in folate pathway and transporter genes on pemetrexed treatment outcome in Slovenian patients with MPM. METHODS:MPM patients treated with pemetrexed in the course of a prospective randomized clinical trial were genotyped for nineteen polymorphisms in five genes of folate pathway and six transporter genes. Logistic regression was used to assess the influence of polymorphisms on treatment efficacy and toxicity, while Cox regression was used to determine their influence on progression-free and overall survival. RESULTS:Patients with at least one polymorphic MTHFD1 rs2236225 allele had a significantly lower response rate (p = 0.005; odds ratio [OR] = 0.12; 95% confidence interval [CI] = 0.03-0.54) and shorter progression-free survival (p = 0.032; hazard ratio [HR] = 3.10; 95% CI = 1.10-8.74) than non-carriers. Polymorphisms in transporter genes did not influence survival; however, several were associated with toxicity. Liver toxicity was significantly lower in carriers of polymorphic ABCC2 rs2273697 (p = 0.028; OR = 0.23; 95% CI = 0.06-0.85), SLCO1B1 rs4149056 (p = 0.028; OR = 0.23; 95% CI = 0.06-0.85) and rs11045879 (p = 0.014; OR = 0.18; 95% CI = 0.05-0.71) alleles compared to non-carriers, as well as in patients with SLCO1B1 GCAC haplotype (p = 0.048; OR = 0.17; 95% CI = 0.03-0.98). Gastrointestinal toxicity was much more common in patients with polymorphic ABCC2 rs717620 allele (p = 0.004; OR = 10.67; 95% CI = 2.15-52.85) and ABCC2 CAG haplotype (p = 0.006; OR = 5.67; 95% CI = 1.64-19.66). CONCLUSIONS:MTHFD1 polymorphism affected treatment response and survival, while polymorphisms in ABCC2 and SLCO1B1 transporter genes influenced the risk for toxicity. These polymorphisms could serve as potential markers of pemetrexed treatment outcome in patients with MPM.

Project description:Malignant pleural mesothelioma (MPM) is a highly lethal, poorly understood neoplasm that is typically associated with asbestos exposure. We performed transcriptional profiling using high-density oligonucleotide microarrays containing approximately 22,000 genes to elucidate potential molecular and pathobiological pathways in MPM using discarded human MPM tumor specimens (n=40), normal lung specimens (n=4), normal pleura specimens (n=5), and MPM and SV40-immortalized mesothelial cell lines (n=5). In global expression analysis using unsupervised clustering techniques, we found two potential subclasses of mesothelioma which correlate loosely with tumor histology. We also identified sets of genes with expression levels that distinguish between multiple tumor subclasses, normal and tumor tissues, and tumors with different morphologies. Microarray gene expression data were confirmed using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and protein analysis for three novel candidate oncogenes (NME2, CRI1, and PDGFC) and one candidate tumor suppressor (GSN). Finally, we used bioinformatics tools (i.e. software) to create and explore complex physiological pathways that may be relevant in mesothelioma tumorigenesis, pathobiology, or both. Tissues and cell lines profiled using microarrays. Discarded MPM surgical specimens (n=40), normal pleura specimens (n=5), and normal lung specimens (n=4) were freshly collected (and snap frozen) from patients who underwent surgery at Boston's Brigham and Women's Hospital (BWH) between October 1998 and August 2000. All of these patients underwent extrapleural pneumonectomy with heated intra-pleural cisplatin chemotherapy delivered after the specimens were removed. All normal specimens were obtained from patients who were never diagnosed with MPM. Two human MPM cell lines (MS589 and MS428) were kindly provided by Jonathan A. Fletcher, M.D., Department of Pathology, BWH. The JMN1B MPM cell line19,20 has been described previously. The SV40-immortalized, non-tumorigenic mesothelial cell line (Met-5A)21 and the MPM cell line MSTO-211H22 were purchased from the American Type Culture Collection. Normal tissues were obtained from additional consented patients undergoing treatment for diseases other than MPM. All MPM samples used in these studies contained relatively pure tumor (greater than 50% tumor cells per high power field examined in a section adjacent to the tissue used). The microscopic slides from the patients' resection specimens were reviewed by one of the authors (J.G.), and the diagnosis and histologic subclassification of MPM confirmed in all cases. Linked clinical and pathological data were obtained for all patients who contributed tumor specimens. Specimens and data were rendered anonymous to protect patient confidentiality. Studies utilizing human tissues were approved by and conducted in accordance with the policies of the Institutional Review Board at BWH.

Dataset Information

Thymidylate synthase and folyl-polyglutamate synthase are not clinically useful markers of response to pemetrexed in patients with malignant pleural mesothelioma.

Purpose

Methods

Results

Conclusions

Publications

Thymidylate synthase and folyl-polyglutamate synthase are not clinically useful markers of response to pemetrexed in patients with malignant pleural mesothelioma.

Similar Datasets

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