Suppression of the growth of human colorectal carcinoma cells (LS174T) by radiolabeled monoclonal antibody (¹³¹I-MAbC27) in tissue culture and nude mice

Abstract

 

A monoclonal antibody against carcinoembryonic antigen (CEA), MAbC27, and its F(ab′)₂ fragments were prepared and labeled with¹³¹I. They effectively suppressed the growth of a human colorectal carcinoma cell line, LS174T, both in culture medium and in inoculated nude mice, whereas¹³¹I-labeled normal mouse immunoglobulin or¹³¹I itself did not have similar effects. Intravenous injection of¹³¹I-MAbC27 or¹³¹I-MAbF(ab′)₂ following inoculation of carcinoma cells suppressed their growth in vivo. The suppression effect was even more effective when intact antibody rather than its F(ab′)₂ fragments was used, especially when the treatment was repeated. This study indicates that radiolabeled MAbC27 may be used as a therapeutic agent in CEA-secreting human colorectal carcinomas.