Reactivity of Monoclonal Antibodies Directed against Lung Cancer Antigens with Human Lung, Breast and Colon Cancer Cell Lines

A panel of monoclonal antibodies (n=72 including controls) directed against lung cancer antigens was screened immunohistochemically against a panel of seven human lung cancer cell lines (including small cell carcinoma, squamous cell carcinoma, adenocarcinoma and mesothelioma), six human breast cancer cell lines and one human colon cancer cell line, The majority of the antibodies (n=42) reacted also with antigens present on breast and colon cancer cell lines, This cross reactivity especially between lung and breast cancer cell lines is not altogether unexpected since antigens common to breast and lung tissue including their neoplasms such as MUC1 antigen have been described, Our results indicate that epitopes shared by lung and breast cancers are probably more common than previously thought. The relevance for prognosis and therapy of these shared antigens, especially as disease markers in breast cancer, has to be investigated.