Modification of blood group A antigen expression in a pancreatic cancer cell line (PC‐1) by inhibitors of N‐glycan processing

Pancreatic adenocarcinomas induced in Syrian hamsters by treatment with N‐nitrosobis(2‐oxopropyl) amine express blood group A antigen, which is absent in normal pancreatic cells. On membrane glycoproteins purified from tumors, blood group A antigen has been found to be expressed on multiantennary Asn‐linked complex glycans. In this study, we investigated the effect of inhibitors of Asn‐glycan processing on blood group A antigen bearing glycan structures in a cell line (PC‐1) established from a primary induced pancreatic cancer. Expression of blood group A antigen on cells and in membrane preparations was blocked by treatment with 1‐deoxymannojirimycin, an inhibitor of mannosidase I, but was retained after treatment with swainsonine, an inhibitor of mannosidase II. However, swainsonine treatment altered the glycan structure associated with blood group A antigen from an endoglycosidase H resistant type to a sensitive type, indicating that the blood group A structure might shift from a complex type to a hybr‐id type glycan by this treatment. These results demonstrate that Asn‐linked glycans carry the major blood group A antigens in PC‐1 cells. © 1992 Wiley‐Liss, Inc.