title: Characterization of cancer associated mucin type O-glycans using the exchange sialylation properties of mammalian sialyltransferase ST3Gal-II.
abstract: Our previous studies suggest that the α2,3sialylated T-antigen (NeuAcα2,3Galβ1,3GalNac-) and associated glycan structures are likely to be elevated during cancer. An easy and reliable strategy to label mucinous glycans that contain such carbohydrates can enable the identification of novel glycoproteins that are cancer associated. To this end, the present study demonstrates that the exchange sialylation property of mammalian ST3Gal-II can facilitate the labeling of mucin glycoproteins in cancer cells, tumor specimens, and glycoproteins in cancer sera. Results show that (i) the radiolabeled mucin glycoproteins of each of the cancer cell lines studied (T47D, MCF7, LS180, LNCaP, SKOV3, HL60, DU4475, and HepG2) is distinct either in terms of the specific glycans presented or their relative distribution. While some cell lines like T47D had only one single sialylated O-glycan, others like LS180 and DU4475 contained a complex mixture of mucinous carbohydrates. (ii) [14C]sialyl labeling of primary tumor cells identified a 25-35 kDa mucin glycoprotein unique to pancreatic tumor. Labeled glycoproteins for other cancers had higher molecular weight. (iii) Studies of [14C] sialylated human sera showed larger mucin glycopeptides and >2-fold larger mucin-type chains in human serum compared to [14C]sialyl labeled glycans of fetuin. Overall, the exchange sialylation property of ST3Gal-II provides an efficient avenue to identify mucinous proteins for applications in glycoproteomics and cancer research.
authors.affiliation: Department of Cancer Biology, Roswell Park Cancer Institute, Buffalo, New York 14263, United States. gchandrasek@yahoo.com
authors.forename: E V
authors.initials: EV
authors.lastname: Chandrasekaran
authors.forename: Jun
authors.initials: J
authors.lastname: Xue
authors.forename: Jie
authors.initials: J
authors.lastname: Xia
authors.forename: Robert D
authors.initials: RD
authors.lastname: Locke
authors.forename: Shilpa A
authors.initials: SA
authors.lastname: Patil
authors.forename: Sriram
authors.initials: S
authors.lastname: Neelamegham
authors.forename: Khushi L
authors.initials: KL
authors.lastname: Matta
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood / Q000737:chemistry / Q000378:metabolism; D002247:Carbon Isotopes / Q000737:chemistry / Q000378:metabolism; D045744:Cell Line, Tumor; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006020:Glycopeptides / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008297:Male; D009077:Mucins / Q000097:blood / Q000737:chemistry* / Q000378:metabolism; D019158:N-Acetylneuraminic Acid / Q000737:chemistry / Q000378:metabolism; D009369:Neoplasms / Q000737:chemistry* / Q000378:metabolism*; D011134:Polysaccharides / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D012799:Sialyltransferases / Q000378:metabolism*; D000094663:beta-Galactoside alpha-2,3-Sialyltransferase
chemical_list: D014408:Biomarkers, Tumor; D002247:Carbon Isotopes; D006020:Glycopeptides; D009077:Mucins; D011134:Polysaccharides; D012799:Sialyltransferases; D019158:N-Acetylneuraminic Acid; D000094663:beta-Galactoside alpha-2,3-Sialyltransferase; C000722087:ST3GAL1 protein, human