Objective: In order to tracing the lung cancer, A monoclonal antibody was produced.
Method: The McAb, named SM-1, was specifically reacted with lung cancer confirmed by the immunopathological studies, then the McAb was digested into fragments by ficin and bromelain proteases.
Results: Both of the enzymatic methods were very effective and the immuno-reactivity of fragments was retained well. In our localization experiments, the T/NT ratio revealed that radioiodinated McAb and fragments could be specifically uptaked by the tumour tissue and the T/NT ratio was higher in fragments group than intact IgG. After injection of 131I-IgG and fragments, the xenografts of human lung cancer bearing in nude mice were visualized distinctly during 36-48 hrs. Eighteen patients with lung cancer received Tc-99m labeled McAb intravenously, 13 cases showed radioactive accumulation in the foci of tumours.
Conclusion: These preliminary results suggested that SM-1 and its fragments might be a potential agents for radioimmunoimaging diagnosis of lung cancer.