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.
- SourceAvailable from: Jatinder Kaur
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- "Previously, our study of the secretomes of two TC cell lines, a papillary-derived cell line (TPC-1) and an anaplasticderived cell line (CAL62), demonstrated that secretome proteins are detectable in sera and tissues of TC patients . We identified 46 high-confidence protein IDs in the previous study and confirmed some of the identified proteins in TC patients' samples to assess their clinical significance. "
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 03/2013; 13(5). DOI:10.1002/pmic.201200356 · 3.97 Impact Factor
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- "The criteria of selecting candidates for verification were (i) identification in our earlier iTRAQ studies; (ii) biological relevance; and (iii) prognostic relevance established in tissues in our earlier studies    "
ABSTRACT: In search of blood-based biomarkers that would enhance the ability to diagnose head and neck/oral squamous cell carcinoma (HNOSCC) in early stages or predict its prognosis, we analyzed the HNOSCC secretome (ensemble of proteins secreted and/or shed from the tumor cells) for potential biomarkers using proteomic technologies. LC-MS/MS was used to identify proteins in the conditioned media of four HNOSCC cell lines (SCC4, HSC2, SCC38, and AMOSIII); 140 unique proteins were identified on the basis of 5% global false discovery rate, 122 of which were secretory proteins, with 29 being previously reported to be overexpressed in HNOSCC in comparison to normal head and neck tissues. Of these, five proteins including α-enolase, peptidyl prolyl isomerase A/cyclophilin A, 14-3-3 ζ, heterogeneous ribonucleoprotein K, and 14-3-3 σ were detected in the sera of HNOSCC patients by Western blot analysis. Our study provides the evidence that analysis of head and neck cancer cells' secretome is a viable strategy for identifying candidate serological biomarkers for HNOSCC. In future, these biomarkers may be useful in predicting the likelihood of transformation of oral pre-malignant lesions, prognosis of HNOSCC patients and evaluate response to therapy using minimally invasive tests.Proteomics 06/2011; 11(12):2363-76. DOI:10.1002/pmic.201000186 · 3.97 Impact Factor
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ABSTRACT: Prothymosin α (ProTα) is a 12.5-kDa, highly acidic protein widely distributed in different cell types expressed intracellularly and extracellularly. ProTα does not contain a secretion-signal sequence and is released by a nonclassical secretory pathway with a cargo protein. New findings on the extracellular function of ProTα have yielded exciting insights into the cytokine-like functions of this host protein that stimulates type I interferon via Toll-like receptor 4. Here, we discuss the intracellular function of ProTα, how new findings of cytokine-like activities of ProTα aid our understanding of mechanisms that direct ProTα functions, and the potential application of these new insights to the development of immunotherapies.Future medicinal chemistry 07/2011; 3(9):1199-208. DOI:10.4155/fmc.11.72 · 4.00 Impact Factor