Radioimmunodetection of human colon cancer in nude mice by a new monoclonal antibody A7 against human colorectal cancer

The in vivo localization of a monoclonal antibody A7 against a human colorectal cancer was studied in nude mice bearing human solid carcinomas, to evaluate potential applications of this antibody for radioimmunodetection of cancer. The tissue distribution of¹²⁵I-labeled A7 MoAb at 3 days after i.v. injection into mice bearing five different kinds of human solid tumors revealed a high uptake ratio by colon cancer, mammary cancer, and glioblastoma. In contrast, the uptake ratio by murine colorectal cancer (Colon-38) was extremely low. In immunoscintigraphic studies, HCT-15, one of the human colon cancer, was clearly visualized with ¹¹¹In-DTPA-A7 MoAb. Glioblastoma was also imaged with the same extent. These results suggest that A7 MoAb would be applicable to the in vivo radioimmunodetection of colon- and mammary-cancer, and of glioblastoma.