Purification and characterization of a pancreatic cancer-associated antigen (PCAA) from normal colonic mucosa.

The same antigenic substance as pancreatic cancer-associated antigen (PCAA), sharing an identical immunogenicity with Gelder's POA, was isolated and purified from normal colonic mucosa. Purified colonic PCAA (PCAAc) is a glycoprotein with a molecular weight of approximately 600,000; it consists of 30% carbohydrates and 70% peptides, and appears to be an N-glycosidic glycoprotein. Antiserum raised against purified PCAAc showed one fused line with our original anti-PCAA antiserum to ascites fluid from patients with pancreatic cancer and extract from normal colonic mucosa. Circulating PCAAc levels assayed by rocket immunoelectrophoresis showed significant elevation in sera of patients with carcinoma of the pancreas. It is concluded that PCAA might be a new tumor-associated antigen which is produced ectopically during oncogenesis.