title: 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.
authors.affiliation: Joseph and Mildred Sonshine Family Centre for Head and Neck Diseases, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Kashat
authors.forename: Anthony K-C
authors.initials: AK
authors.lastname: So
authors.forename: Olena
authors.initials: O
authors.lastname: Masui
authors.forename: X Simon
authors.initials: XS
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Cao
authors.forename: Xianwang
authors.initials: X
authors.lastname: Meng
authors.forename: Christina
authors.initials: C
authors.lastname: Macmillan
authors.forename: Laurie E
authors.initials: LE
authors.lastname: Ailles
authors.forename: K W Michael
authors.initials: KW
authors.lastname: Siu
authors.forename: Ranju
authors.initials: R
authors.lastname: Ralhan
authors.forename: Paul G
authors.initials: PG
authors.lastname: Walfish
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000032:analysis*; D045744:Cell Line, Tumor; D051152:Clusterin; D055515:Cysteine-Rich Protein 61; D004268:DNA-Binding Proteins; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D009363:Neoplasm Proteins / Q000032:analysis* / Q000378:metabolism; D010750:Phosphoproteins; D010751:Phosphopyruvate Hydratase; D040901:Proteomics / Q000379:methods; D000644:Quaternary Ammonium Compounds; D016601:RNA-Binding Proteins; D013964:Thyroid Neoplasms / Q000737:chemistry* / Q000175:diagnosis; D014183:Transplantation, Heterologous; D025521:Tumor Suppressor Proteins; D000097796:Nucleolin
chemical_list: D014408:Biomarkers, Tumor; D051152:Clusterin; D055515:Cysteine-Rich Protein 61; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D010750:Phosphoproteins; D010751:Phosphopyruvate Hydratase; D000644:Quaternary Ammonium Compounds; D016601:RNA-Binding Proteins; D025521:Tumor Suppressor Proteins; D000097796:Nucleolin; C501848:CCN1 protein, human; C001420:3-hydroxyphenyltrimethylammonium; C095157:ENO1 protein, human