RETURNYonago Acta medica 1991;34:217-226
Production of Monoclonal Antibodies Defining Human Melanoma-Associated Antigens Susceptible to Induction by n-Butyric Acid
Hidetoshi Nakayama
Department of Dermatology, Faculty of Medicine, Tottori University, Yonago 683, Japan
Two melanoma-associated monoclonal antibodies, MT-24 and MAT-60, were produced. A-375 human melanoma cells showed certain morphologic changes after treatment with n-butyric acid. The melanoma cells, spindle shaped under normal culture conditions, became dendritic and/or round after treatment. These dendritic and/or round cells then recovered their spindle shape after subsequent culturing in a normal culture medium. The mitotic rate of the melanoma cells was detected by measuring the incorporation of the monoclonal antibody Ki-67 into the nucleus using immunohistochemistry. The percentage of Ki-67 positive cells decreased after treatment, then increased after the withdrawal of n-butyric acid. MT-24 was produced using melanoma cells treated with n-butyric acid for 24 h, and MAT-60 using melanoma cells after withdrawal of n-butyric acid for 60 h, as immunogens. The reactivities of these antibodies were assessed by the immunohistochemical analysis of frozen malignant melanomas (metastatic and primary melanomas) and benign nevus cell nevi (junctional nevi, compound nevi and intradermal nevi). All nevus cell nevi and primary melanomas were reactive with MT-24, while metastatic melanomas were nonreactive. MAT-60 reacted with all melanomas, junction nevi and compound nevi, but did not react with intradermal nevi. These results suggest that the reactivity of MT-24 and MAT-60 might be related to tumor progression in melanocytic proliferation.
Key words: melanoma-associated monoclonal antibody; MT-24 and MAT-60; n-butyric acid