Ectopic expression of the Y (Ley) antigen defined by monoclonal antibody 12-4LE in distal colonic adenocarcinomas.

Monoclonal antibody (MAb) 12-4LE reacts specifically with the alpha Fuc(1-2) beta Gal(1-4) [alpha Fuc(1-3)]GlcNAc-R synthetic oligosaccharide and consequently characterizes the Y (Ley) antigen. In normal individuals, this MAb reacts more strongly on samples from blood group O persons, indicating that the Y structure is better recognized when terminal A or B sugars are not added to the Y structure. In fetal and normal adult gastrointestinal tract, this antibody reacts with the epithelium of stomach, small intestine and proximal colon, but not of distal colon.

Biosynthesis of Lewis antigenic glycolipid by cell-free extracts of human intestinal tumor cells cultured in serum-free medium.

Extracts of the human intestinal tumor cell line SW1116 were able to stimulate the incorporation of (14C) fucose from GDP-(14C) fucose into organically soluble glycolipid. The reaction required a purified glycolipid preparation from human meconium as lipid acceptor. The active glycolipid co-migrated with standard globoside on high performance thin-layer chromatography (HPTLC) and had molecular species (M + H) under fast-atom bombardment mass spectrometry of 1199, 1245 and 1269.

Alterations in expression and synthesis of glycolipid antigens in human colonic tumor cell lines.

Incubation of human intestinal SW1116 tumor cells in serum-free medium containing butyric acid reduced their capacity to synthesize gastrointestinal carcinoma-associated (GICA) glycolipid antigen 4- to 8-fold as determined by a radioimmunobinding assay using anti-GICA monoclonal antibody:high-performance thin-layer chromatography; autoradiography; and densitometry. The structure of GICA has been described as a sialylated Lea glycolipid (J. L.