Purification and characterization of a pancreas cancer-associated antigen from normal colonic mucosa

Pancreas cancer-associated antigen (PCAAc) was extracted, isolated and purified from human normal colonic mucosa. Purified PCAAc from normal colonic mucosa was homogeneous, as determined by polyacrylamide disc gel electrophoresis. The PCAAc had a molecular weight of approximately 600 000 and consisted of 30% carbohydrate and 70% protein. It had an isoelectric point of 4.4, and migrated to the alpha 2-beta region on immunoelectrophoresis. It was apparently different from other known gastrointestinal mucus antigens. Antiserum against purified PCAAc did not react with normal human serum, pancreas, liver, spleen or lung, but did react with ascites fluid from a patient with pancreatic cancer. PCAAc appears to be a mucus antigen that is associated with pancreatic cancer.