Specific cytotoxic effect of neocarzinostatin conjugated to monoclonal antibody A7 on human pancreatic carcinoma.

The anti-cancer drug neocarzinostatin (NCS) was bound covalently to the monoclonal antibody A7 to form the conjugate A7-NCS. This antibody was produced by fusing the spleen cells of a mouse immunized against human colonic carcinoma with murine myeloma cells and reacts with a high percentage of human pancreatic carcinoma cell lines and with no normal human pancreas tissue by immunoperoxidase staining. The cytotoxic effect of A7-NCS was tested by measuring the inhibition of 3H-thymidine incorporation into human pancreatic carcinoma cells. The A7-NCS was approximately 2.7 times as effective as free NCS against human pancreatic carcinoma cells which reacted with the monoclonal antibody A7. A7-NCS had almost the same cytotoxicity a free NCS on human pancreatic carcinoma cells which did not react with the monoclonal antibody A7. A7-NCS appeared to be potentially useful as a conjugate for immunotargeting chemotherapy against pancreatic carcinoma.