Comparison of the radiotoxicity of two alpha-particle-emitting immunoconjugates, terbium-149 and bismuth-213, directed against a tumor-specific, exon 9 deleted (d9) E-cadherin adhesion protein.

Abstract Miederer, M., Seidl, C., Beyer, G-J., Charlton, D. E., Vranjes-Duric, S., Comor, J. J., Huber, R., Nikula, T., Apostolidis, C., Schuhmacher, C., Becker, K-F. and Senekowitsch-Schmidtke, R. Comparison of the Radiotoxicity of Two Alpha-Particle- Emitting Immunoconjugates, Terbium-149 and Bismuth-213, Directed against a Tumor-Specific, Exon 9 Deleted (d9) E-Cadherin Adhesion Protein. Radiat. Res. 159, 612–620 (2003). We investigated the effects of the α-particle emitters 149Tb and 213Bi coupled to a tumor-specific antibody targeting the mutated delta 9 E-cadherin (d9 E-Cad) on single cells and cell pellets. The d9 mutation of the adhesion molecule E-cadherin is found in 10% of diffuse-type gastric cancers and is not expressed in normal tissue. Human breast cancer cells (MDA-MB-435S) transfected with d9 E-Cad or the wild-type E-cadherin gene were used to study the effects of anti-d9 E-Cad MAb coupled to 149Tb and 213Bi (149Tb-d9 MAb and 213Bi-d9 MAb). The density of binding sites determined on transf...