Tumour-associated and differentiation antigens on the carbohydrate moieties of mucin-type glycoproteins

Abstract

In this report the carbohydrate antigens expressed on the three oligosaccharide domains, core, backbone and peripheral, of mucin-type glycoproteins are briefly reviewed in the light of recent observations with monoclonal antibodies. These have revealed that a number of cell-surface antigens which behave as tumour-associated and differentiation antigens of man or mouse are abundantly expressed on the carbohydrate chains of a variety of secreted mucins of human and animal origins and they belong to an antigen system which also includes the major blood group antigens. Examples are given of the use of well-characterized anti-carbohydrate antibodies to derive structural information on (a) mucin-type glycoproteins of human B lymphocyte membranes, (b) the high molecular weight glycoproteins of the normal human gastric and distal-colon mucosae and (c) tumour-derived glycoproteins from these two organs. Major differences between the antigenicities of the normal stomach and distal-colon, and between their tumour-derived glycoproteins, and the important effect of the secretor status in the expression of these antigens are described. These observations have enabled a better understanding of the individual and tissue differences in the expression of tumour-associated antigens. The possibility is raised that these carbohydrate structures (many of which also occur on certain N-linked oligosaccharides and glycolipids) are components of receptor systems for endogenous ligands. More tangible evidence is cited for the role of certain structures in this family of saccharides as receptors for infective agents.

Altered mucin expression in the gastrointestinal tract: a review

“…1. The oligosaccharide chains can be considered to have three structurally distinct domains: a core region incorporating the linkage to the protein, a backbone, and a peripheral region [5,6]. Among the four best-established core structure, core 3 structure is well represented within gastrointestinal mucin: GlcNAc∃→3GalNAc-Oserine/threonine [1,2].…”

Recent Advances in Electrophoresis of Mucins

“…The other four spots showed a complicated glycan profile consisting of a variety of glycans. relative intensities of glycan signals (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) in the MS spectra were represented as histograms (Fig. 9).…”

“…Mucins contribute to the protection and lubrication of the mucosal epithelia, while alterations of mucin species and O-linked glycan structures in the mucins have been implicated in tumor progression, and infection for several decades (1)(2)(3)(4)(5). The majority of tumorassociated glycan antigens, including CA19-9, are believed to be the glycans found on mucins (6,7). Using proteomic techniques, many studies aim to discover protein biomarkers by comparing the proteomes of a number of clinical specimens.…”

Ca 125 and Ca 19–9: two cancer‐associated sialylsaccharide antigens on a mucus glycoprotein from human milk

“…Accordingly, sialylated Lea on glycoproteins of the gastric mucosa is a normal antigen in non-secretors, in secretors, on the other hand, it is associated with gastric adenocarcinomas [25].…”