sodium-dodecyl-sulfate and nitrosobis(2-oxopropyl)amine

Although the hamster pancreas does not express A, B or H blood group antigens, all hamster pancreatic ductal adenocarcinomas induced by treatment with N-nitrosobis(2-oxopropyl)amine express blood group-A antigen. Thus, the acquisition of blood group-A antigen expression in this system is a cancer-associated alteration. We have purified three major blood group-A antigen bearing glycoproteins (gp120, gp135 and gp150) from hamster pancreatic cancer cell membrane preparations using affinity chromatography on DBA (Dolichos biflorus) agglutinin-agarose. When assayed by immunoblotting, gp120 and gp135 showed strong blood group-A reactivity, which was removed by treating membrane samples with peptide-N-glycosidase F. Blood group-A reactivity was unchanged by treatment of the membrane fractions with endoglycosidases F and H. In addition, these two glycoproteins bearing blood group-A antigen also bound L-PHA (Phaseolus vulgaris leucoagglutinin). These results demonstrate that gp120 and gp135 express blood group-A antigen on Asn-linked multi-antennary complex type glycan structures. The gp150 showed weak blood group-A expression. This is the first demonstration of the neoexpression of cancer-associated blood group-A determinants which reside on Asn-linked glycan structures.

Topics: ABO Blood-Group System; Animals; Antigens, Neoplasm; Carcinogens; Carcinoma, Intraductal, Noninfiltrating; Cricetinae; Electrophoresis, Polyacrylamide Gel; Epitopes; Glycoside Hydrolases; Immunoblotting; Lectins; Membrane Glycoproteins; Nitrosamines; Oligosaccharides; Pancreas; Pancreatic Neoplasms; Plant Lectins; Sodium Dodecyl Sulfate; Tumor Cells, Cultured

The subcellular localization and biochemical characteristics of blood group A antigen were studied by immunogold methods and by SDS-PAGE and Western blotting procedures in N-nitrosobis)2-oxopropyl)amine (BOP)-induced pancreatic cancer (PC) in Syrian hamsters, in the pancreatic cancer cell line (PC-1) derived from a primary induced pancreatic cancer, and in intrapancreatic and subcutaneous transplants of PC-1 cells. Normal hamster duodenal epithelial cells expressing A antigen were compared with the normal hamster pancreas (lacking A antigen), human PC tissues from patients with blood group A and human PC cell lines. Blood group A antigen was present on the membrane of hamster duodenal cells, but was absent in the normal pancreatic cells. A antigen was localized mainly on the cell membrane of the hamster cancer cells both in vivo and in vitro. Glycoproteins with blood group A specificity were observed by SDS-PAGE and Western blotting procedures in the membrane fraction of PC-1 cells, with a major component of molecular mass of approximately 120 kd. Similar migration patterns were observed in the primary induced PC and in subcutaneous and intrapancreatic transplants of PC-1 cells. Membrane preparations from cell lines derived from two primary pancreatic cancers from patients of blood group A and from human pancreatic cell lines, CD11 and CD18, showed a major A reactive component with a molecular mass similar to that found in the hamster PC cells. These findings suggest that: (i) both the hamster and human PC cells in vitro produce glycoproteins with blood group A specificity of similar molecular masses; (ii) differences exist in the structure of the glycoprotein immunoreactive with the anti-A antigen between the normal and cancerous cells; and (iii) differences exist in the molecular mass of the anti-A reactive substance between hamsters and human PC cells and between tissues in vivo and in vitro.

Topics: ABO Blood-Group System; Adenocarcinoma; Animals; Antibodies, Monoclonal; Antigens, Differentiation; Blotting, Western; CD11 Antigens; CD18 Antigens; Cell Membrane; Cricetinae; Duodenum; Electrophoresis, Polyacrylamide Gel; Humans; Immunohistochemistry; Injections, Subcutaneous; Microscopy, Electron; Neoplasm Transplantation; Nitrosamines; Pancreas; Pancreatic Neoplasms; Receptors, Leukocyte-Adhesion; Sodium Dodecyl Sulfate; Subcellular Fractions; Tumor Cells, Cultured