title: Identification of potential pancreatic cancer serum markers: Increased sialyl-Lewis X on ceruloplasmin.
abstract: Pancreatic adenocarcinoma (PDAC) usually shows an enhanced expression of sialyl-Lewis X (sLe(x)) and related epitopes. PDAC may secrete some of the proteins carrying such increased sLe(x) determinant into serum, so they could be used as PDAC markers. Previously, we identified acute-phase proteins with increased sLe(x) in both PDAC and in chronic pancreatitis patients. In this study, depleted sera from the main acute-phase proteins has been analysed for the search of proteins with increased sLe(x) levels in PDAC. Sera from healthy controls, chronic pancreatitis and PDAC patients were depleted, electrophoresed and subjected to sLe(x) immunodetection. Proteins that differentially expressed sLe(x) in PDAC were trypsin digested and identified by LC-ESI-QTOF mass spectrometry. Five protein bands that differentially expressed sLe(x) in PDAC were identified and corresponded to seven different acute-phase proteins. Among them, ceruloplasmin (CP) was selected for further analysis. N-glycan sequencing of CP confirmed the increase of sLe(x) levels in CP in PDAC patients. Healthy controls, chronic pancreatitis and PDAC patients' sera were immunoprecipitated with anti-CP antibodies, and their sLe(x) and CP levels were analysed by western blot. The sLe(x)/CP ratio tended to be higher for the PDAC group, which altogether suggests that the sLe(x)/CP ratio could be a useful biomarker for PDAC.
authors.affiliation: Department of Biology, University of Girona, Girona, Spain.
authors.forename: Meritxell
authors.initials: M
authors.lastname: Balmaña
authors.affiliation: Department of Biology, University of Girona, Girona, Spain.
authors.forename: Ariadna
authors.initials: A
authors.lastname: Sarrats
authors.affiliation: Department of Biology, University of Girona, Girona, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Llop
authors.affiliation: Department of Biology, University of Girona, Girona, Spain.
authors.forename: Sílvia
authors.initials: S
authors.lastname: Barrabés
authors.affiliation: NIBRT GlycoScience Group, National Institute for Bioprocessing Research and Training, Dublin, Ireland.
authors.forename: Radka
authors.initials: R
authors.lastname: Saldova
authors.affiliation: Laboratory ICS Girona, Dr. Josep Trueta University Hospital, Girona, Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: Ferri
authors.affiliation: Department of Surgery, Dr. Josep Trueta University Hospital, IdlBGi, Girona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Figueras
authors.affiliation: Digestive Unit, Dr. Josep Trueta University Hospital, Girona, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Fort
authors.affiliation: Department of Biology, University of Girona, Girona, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: de Llorens
authors.affiliation: NIBRT GlycoScience Group, National Institute for Bioprocessing Research and Training, Dublin, Ireland.
authors.forename: Pauline M
authors.initials: PM
authors.lastname: Rudd
authors.affiliation: Department of Biology, University of Girona, Girona, Spain. Electronic address: rosa.peracaula@udg.edu.
authors.forename: Rosa
authors.initials: R
authors.lastname: Peracaula
mesh_terms: D000230:Adenocarcinoma / Q000097:blood* / Q000473:pathology; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D016022:Case-Control Studies; D045744:Cell Line, Tumor; D002570:Ceruloplasmin / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006023:Glycoproteins / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D009844:Oligosaccharides / Q000097:blood*; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000473:pathology; D050500:Pancreatitis, Chronic / Q000097:blood; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D000080506:Sialyl Lewis X Antigen
chemical_list: D014408:Biomarkers, Tumor; D006023:Glycoproteins; D009844:Oligosaccharides; D011134:Polysaccharides; D000080506:Sialyl Lewis X Antigen; D002570:Ceruloplasmin
keywords: Acute-phase proteins; Biomarker; Ceruloplasmin; Pancreatic cancer; Pancreatitis; Sialyl-Lewis X