Pancreatic tumor antigen (PTA) was purified to apparent homogeneity from hamster pancreatic adenocarcinomas by a rapid and simple procedure using column chromatography on Mono P and Superose 6. Amino acid analysis indicated essential similarities between hamster PTA and human pancreatic cancer-associated antigen (PCAA, PCAAc), although differences in the contents of several amino acid residues between the two proteins did suggest species variation. Investigation of the binding pattern of antibody raised against PTA by peroxidase-labeled antibody immunocytochemistry revealed that, whereas PTA is absent or only faintly expressed in normal epithelium, it is very strongly positive in transplantable hamster pancreatic adenocarcinomas induced by nitrosamines. PTA was found to be distributed over the entire surface of neoplastic cells and it was concluded that the presence of PTA on the basolateral surface of malignant pancreatic epithelial cells, where it. might have access to the blood circulation, could be one explanation for the observed elevated concentrations of PTA in the serum. PTA is thus a potential marker for hamster neoplastic pancreatobiliary duct-type cells.
All Science Journal Classification (ASJC) codes
- Internal Medicine
- Endocrinology, Diabetes and Metabolism