Secretome-based identification and characterization of potential biomarkers in thyroid cancer.
ABSTRACT In search of thyroid cancer biomarkers, proteins secreted by thyroid cancer cell lines, papillary-derived TPC-1 and anaplastic-derived CAL62, were analyzed using liquid chromatography-tandem mass spectrometry. Of 46 high-confidence identifications, 6 proteins were considered for verification in thyroid cancer patients' tissue and blood. The localization of two proteins, nucleolin and prothymosin-α (PTMA), was confirmed in TPC-1 and CAL62 cells by confocal microscopy and immunohistochemically in xenografts of TPC-1 cells in NOD/SCID/γ mice and human thyroid cancers (48 tissues). Increased nuclear and cytoplasmic expression of PTMA was observed in anaplastic compared to papillary and poorly differentiated carcinomas. Nuclear expression of nucleolin was observed in all subtypes of thyroid carcinomas, along with faint cytoplasmic expression in anaplastic cancers. Importantly, PTMA, nucleolin, clusterin, cysteine-rich angiogenic inducer 61, enolase 1, and biotinidase were detected in thyroid cancer patients' sera, warranting future analysis to confirm their potential as blood-based thyroid cancer markers. In conclusion, we demonstrated the potential of secretome analysis of thyroid cancer cell lines to identify novel proteins that can be independently verified in cell lines, xenografts, tumor tissues, and blood samples of thyroid cancer patients. These observations support their potential utility as minimally invasive biomarkers for thyroid carcinomas and their application in management of these diseases upon future validation.
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ABSTRACT: Using proteomics in tandem with bioinformatics, the secretomes of non-aggressive and aggressive thyroid carcinoma (TC) cell lines were analyzed to detect potential biomarkers for tumor aggressiveness. A panel of nine proteins, activated leukocyte cell adhesion molecule (ALCAM/ CD166), tyrosine-protein kinase receptor (AXL), amyloid beta A4 protein (APP), amyloid-like protein 2 (APLP2), heterogeneous nuclear ribonucleoprotein K (hnRNP K), phosphoglycerate kinase 1 (PGK1), pyruvate kinase isozyme M2 (PKM2), phosphatase 2A inhibitor (SET), and protein kinase C inhibitor protein 1 (14-3-3 zeta) was chosen to confirm their expression in TC patients' sera and tissues. Increased pre-surgical circulating levels of ALCAM were associated with aggressive tumors (p = 0.04) and presence of lymph node metastasis (p = 0.018). Increased serum AXL levels were associated with extrathyroidal extension (p = 0.027). Furthermore, differential expression of APP, AXL, hnRNP K, PGK1, PKM2, and SET was observed in TC tissues compared to benign nodules. Decreased nuclear expression of AXL can detect malignancy with 90% specificity and 100% sensitivity (AUC = 0.995, p < 0.001). In conclusion, some of these proteins show potential for future development as serum and/or tissue-based biomarkers for TC and warrant further investigation in a large cohort of patients.Proteomics 01/2013; · 4.43 Impact Factor
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ABSTRACT: The definition of the secretome signature of a cancer cell line can be considered a potential tool to investigate tumor aggressiveness and a preclinical exploratory study required to optimize the search of cancer biomarkers. Dealing with a cell-specific secretome limits the contamination by the major components of the human serum and reduces the range of dynamic concentrations among the secreted proteins, thus favouring under-represented tissue-specific species. The aim of the present study is to characterize the secretome of two human colon carcinoma cell lines, CaCo-2 and HCT-GEO, in order to evaluate differences and similarities of two colorectal cancer model systems. In this study, we identified more than 170 protein species, 64 more expressed in the secretome of CaCo-2 cells and 54 more expressed in the secretome of HCT-GEO cells; 58 proteins were shared by the two systems. Among them, more than 50% were deemed to be secretory according to their Gene Ontology annotation and/or to their SignalP or SecretomeP scores. Such a characterization allowed to corroborate the potential of a cell culture-based model in order to describe the cell-specific invasive properties and to provide a list of putative cancer biomarkers. J. Cell. Biochem. © 2013 Wiley Periodicals, Inc.Journal of Cellular Biochemistry 06/2013; · 3.06 Impact Factor
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ABSTRACT: Background: We previously identified two highly discriminating and predictive radiation-induced transcriptomic signatures by comparing series of sporadic and post-radiotherapy thyroid tumors (322-gene signature), and by re-analyzing a previously published dataset of sporadic and post-Chernobyl thyroid tumors (106-gene signature). The aim of the present work was 1) to compare the two signatures in terms of gene expression deregulations and molecular features/pathways and 2) to test the capacity of the post-radiotherapy signature in classifying the post-Chernobyl series of tumors and reciprocally of the post Chernobyl signature in classifying the post-radiotherapy induced tumors. Methods: We now explored if post-radiotherapy and post-Chernobyl thyroid papillary carcinomas (PTC) display common molecular features by comparing molecular pathways deregulated in the two tumor series and test the potential of gene subsets of the post-radiotherapy signature to classify the post-Chernobyl series (14 sporadic and 12 post-Chernobyl PTC), and reciprocally of gene subsets of the post-Chernobyl signature to classify the post-radiotherapy series (15 sporadic and 12 post-radiotherapy PTC), by using conventional Principal Component Analysis. Results: We found that the 5 genes common to the two signatures classified the learning/training tumors (used to search these signatures) of both the post-radiotherapy (7 PTC) and the post-Chernobyl (6 PTC) thyroid tumor series as compared with the sporadic tumors (7 sporadic PTC in each series). Importantly, these 5 genes were also effective for classifying independent series of post-radiotherapy (5 PTC) and post-Chernobyl (6 PTC) tumors compared to independent series of sporadic tumors (8 PTC and 6 PTC, respectively) (testing tumors) Moreover, part of each post-radiotherapy (32 genes) and post-Chernobyl signature (16 genes) cross-classified the respective series of thyroid tumors. Finally, several molecular pathways deregulated in post-Chernobyl tumors matched those found to be deregulated in post-radiotherapy tumors. Conclusions Overall, our data suggest that thyroid tumors that developed following either external exposure or internal 131I contamination shared common molecular features, related to DNA repair, oxidative and endoplasmic reticulum stresses, allowing their classification as radiation-induced tumors in comparison with sporadic counterparts, independently of doses and dose rates, which suggests there may be a "general" radiation-induced signature of thyroid tumors.Thyroid: official journal of the American Thyroid Association 03/2013; · 2.60 Impact Factor