BACKGROUNDTo evaluate potential clinical roles of monoclonal antibody (MoAb)-based radioimmunotherapy in the treatment of lung cancer.

METHODSAnti-lung cancer monoclonal antibody LC-l IgM was combined with ⁹⁰Y to produce radioimmunological targeting drug. Human lung cancer tissue was inoculated subcutaneously in 35 nude mice. They were randomized into seven groups while the tumor was 5 mm in diameter. The groups were divided by the dose of the drug injected to the tail vein of the mice: blank group, LC-1 IgM alone, ⁹⁰Y 50 μCi alone, 50 μCi, 150 μCi, 300 μCi, and 400 μCi combined therapy groups. The size of the tumor was measured weekly and the mice were killed in four weeks after treatment. The tumors were resected and weighed.

RESULTSAs compared to blank group, therapy groups' tumor growth was inhibited and the inhibition was dose- and time-dependent. The inhibition rates of 300 μCi and 400 μCi groups were significantly different (P < 0.05). The nuclei of tumor cells showed karyopycnosis, structure disorder and rupture after treatment by pathological exam. In some regions, the tumor cells were necrotic or disappeared.

CONCLUSIONSThe results indicate that the radioimmunological drug made from lung cancer monoclonal antibody LC-1 IgM and ⁹⁰Y can specifically localise in tumor tissue and ensure radioimmunological targeting therapy, so has underlying clinical value.