Characterization of a murine monoclonal antibody, 5D-4, reacting with pancreatic cancers and islets of Langerhans

A murine monoclonal antibody (5D-4) was prepared by immunizing mice ip with human pancreatic cancer cell line (AsPC-1). The 5D-4 MAb reacted immunohistochemically with pancreatic and gastrointestinal tract tumors as well as pancreatic islets, and to a less extent with normal tissues. The 5D-4 MAb reacted not only with ca 50 KDa and 30 KDa solubilized protein from AsPC-1 cells by Western blot analysis but also with human insulin in a competition RIA. Double immunoperoxidase staining showed that the 5D-4 MAb cross-reacted with insulin but did not react with glucagon, somatostatin or pancreatic polypeptide. Immunoelectron micrograph of Langerhans island double-stained with the 5D-4 MAb and anti-insulin Ab revealed that the 5D-4 Mab recognized human insulin and ca 50 KDa and 30 KDa antigens in B-cells of islets of Langerhans. Thus, the 5D-4 Mab may be useful for the diagnosis of islet cell tumors as well as pancreatic cancers. pancreatic cancer / murine monoclonal antibody / human insulin