Radioimmunoscintigraphy of human colon cancer xenografts in mice with radioiodinated monoclonal antibody B72.3.
Monoclonal antibody B72.3 reacts with a tumor-associated antigen that is found on human breast and colon carcinomas in significantly higher concentration than in normal adult tissues. Intact B72.3 IgG was labeled with I-131 or I-125 and injected into athymic mice bearing xenografts of human colon cancer. Whole-body scintiphotos obtained with a pinhole collimator demonstrated tumor localization within 24 hr after intravenous administration, and the tumor-to-background ratio rose continuously for at least 14 days. Progressive antibody accumulation was observed in the tumor during the first 3 days, but no significant normal organ localization was observed at any time. No localization was seen in control tumors, a human melanoma xenograft that lacks the antigen recognized by B72.3. The pharmacokinetics of this antibody in tumor-bearing mice suggest that I-131 B72.3 may be useful for radioimmunotherapy as well as radioimmunoscintigraphy of colon cancer in man.
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging* / Q000276:immunology; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008545:Melanoma / Q000000981:diagnostic imaging; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D013997:Time Factors; D014055:Tomography, Emission-Computed; D014183:Transplantation, Heterologous
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D007457:Iodine Radioisotopes