Radioimmunotherapy with alpha-particle-emitting immunoconjugates.
Alpha particles are energetic short-range ions whose higher linear energy transfer produces extreme cytotoxicity. An alpha-particle-emitting radioimmunoconjugate consisting of a bismuth-212-labeled monoclonal immunoglobulin M specific for the murine T cell/neuroectodermal surface antigen Thy 1.2 was prepared. Analysis in vitro showed that the radioimmunoconjugate was selectively cytotoxic to a Thy 1.2+ EL-4 murine tumor cell line. Approximately three bismuth-212-labeled immunoconjugates per target cell reduced the uptake of [3H]thymidine by the EL-4 target cells to background levels. Mice inoculated intraperitoneally with EL-4 cells were cured of their ascites after intraperitoneal injection of 150 microcuries of the antigen-specific radioimmunoconjugate, suggesting a possible role for such conjugates in intracavitary cancer therapy.
D000512:Alpha Particles; D000818:Animals; D000954:Antigens, Surface; D001729:Bismuth / Q000627:therapeutic use; D007075:Immunoglobulin M; D007167:Immunotherapy; D008223:Lymphoma / Q000532:radiotherapy*; D051379:Mice; D008810:Mice, Inbred C57BL; D011868:Radioisotopes / Q000627:therapeutic use; D018800:Thy-1 Antigens
D000954:Antigens, Surface; D007075:Immunoglobulin M; D011868:Radioisotopes; D018800:Thy-1 Antigens; D001729:Bismuth