Radioimmunolocalization and biodistribution of ~(125)I labeled Anti-C-erbB-2 monoclonal antibody ICR12 in nude mice bearing human breast cancer xenografts

Objective To study the distribution of12s I labeled anti-C-erbB-2 monoclonal antibodyICR12 (125I-ICR12) and normal mice IgG in nude rnice bearing human breast cancer and to provide thebasis for radioimmunoimaging (RII) and clinical use. Methods. 92. 5 KBq/0. 1 ml labeled antibodywas injected into the tail vein in each mouse respectively. Radioactivity ratio of tumor and non-tumor(T/NT), percent injected dosage of every gram tissue (%ID/g), and localization index (LI) were measured after 24, 48, 98, 120 h interval of injection. Results Radioactivity concentration in tumor wasfound during the 24 to 120 h after the 125I-ICR12 injection. The peak value of T/NT was 19. 374 at 120h, but non-concentration of 125I-mIgG was found, which was distributed evenly in body. ConclusionsICR12 had affinity to breast cancer which overexpressed C-erbB-2 in nude mice bearing human breastcancer xenografts. ICR12 is prospective to be used as the direct carrier of breast cancer diagnosis.[