Association of the Y hapten with glycoproteins, glycolipids and carcinoembryonic antigen in colorectal carcinoma.

The expression of the Y hapten (Fuc alpha 1----2Gal beta 1----4[Fuc alpha 1----3]GlcNAc-) defined by the monoclonal antibody C14/1/46/10 (abbreviated to C14), is frequently elevated in colo-rectal tumours in comparison to adjacent, apparently normal tissues. This determinant was shown to be expressed upon glycoproteins of approximately 200 kDa, which were isolated by immunoadsorbent chromatography from detergent-solubilized subcellular membranes and cytosol from colo-rectal carcinoma. In addition, the Y hapten was expressed upon purified carcinoembryonic antigen (CEA, 180 kDa). However, monoclonal antibodies specifically reactive with CEA or cross-reactive with CEA and NCA-1 (normal cross-reacting antigen) failed to react with the C14 defined antigens of 200 kDa. Further diversity in the expression of molecules bearing the Y hapten was established following its identification in the glycolipid fraction of colo-rectal carcinoma.