Probing the O-Glycoproteome of Gastric Cancer Cell Lines for Biomarker Discovery

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Campos, D (Author) Other; Freitas, D (Author) Other; Gomes, J (Author) Other; Magalhaes, A (Author) Other; Steentoft, C (Author) Other; Gomes, C (Author) Other; Vester Christensen, MB (Author) Other; Ferreira, JA (Author) Other; Afonso, LP (Author) Other; Santos, LL (Author) Other; de Sousa, JP (Author) Other; Mandel, U (Author) Other; Clausen, H (Author) Other; Vakhrushev, SY (Author) Other; Celso Reis (Author) ICBAS

Journal

Title: MOLECULAR & CELLULAR PROTEOMICS

Vol. 14

Pages: 1616-1629

ISSN: 1535-9476

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 68 Citations

Scopus - 70 Citations

Other information

Authenticus ID: P-00G-5Z3

DOI: 10.1074/mcp.m114.046862

Abstract (EN): Circulating O-glycoproteins shed from cancer cells represent important serum biomarkers for diagnostic and prognostic purposes. We have recently shown that selective detection of cancer-associated aberrant glycoforms of circulating O-glycoprotein biomarkers can increase specificity of cancer biomarker assays. However, the current knowledge of secreted and circulating O-glycoproteins is limited. Here, we used the COSMC KO "SimpleCell" (SC) strategy to characterize the O-glycoproteome of two gastric cancer SimpleCell lines (AGS, MKN45) as well as a gastric cell line (KATO III) which naturally expresses at least partially truncated O-glycans. Overall, we identified 499 O-glycoproteins and 1236 O-glycosites in gastric cancer SimpleCells, and a total 47 O-glycoproteins and 73 O-glycosites in the KATO III cell line. We next modified the glycoproteomic strategy to apply it to pools of sera from gastric cancer and healthy individuals to identify circulating O-glycoproteins with the STn glycoform. We identified 37 O-glycoproteins in the pool of cancer sera, and only nine of these were also found in sera from healthy individuals. Two identified candidate O-glycoprotein biomarkers (CD44 and GalNAc-T5) circulating with the STn glycoform were further validated as being expressed in gastric cancer tissue. A proximity ligation assay was used to show that CD44 was expressed with the STn glycoform in gastric cancer tissues. The study provides a discovery strategy for aberrantly glycosylated O-glycoproteins and a set of O-glycoprotein candidates with biomarker potential in gastric cancer.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 14