Accumulation of NCC-CO-411 monoclonal antibody in human colorectal adenocarcinoma through binding of the released carcinoembryonic antigen in nude mice.

Abstract

NCC-CO-411, an anti-carcinoembryonic antigen (CEA) monoclonal antibody (MoAb) showed a dose-dependent reactivity with standard CEA, but did not bind to the CEA anchoring with cell membranes. When LS 174T cells, one of the CEA-producing cells, were treated with phosphatidylinositol-specific phospholipase C, NCC-CO-411 MoAb recognized the released CEA containing glycosylphosphatidylinositol as well as the standard CEA. The binding activity of NCC-CO-411 MoAb with CEA was also demonstrated by the immunostaining of the LS 174T colorectal tumor xenograft tissues. The biodistribution study showed that NCC-CO-411 MoAb was mainly taken up by tumor and kidney, while the anti-hCEA MoAb was largely concentrated in liver and spleen rather than in the tumor. These results suggest that NCC-CO-411 MoAb recognizes the released CEA and gives an excellent tumor image in LS 174T tumor-bearing mice.