Studies on the diagnosis and treatment of human lung cancer using double-layered soft agar cloning assay I. In vitro chemosensitivity test on permanent cell lines from adeno-, epidermoid and small cell carcinoma of the lung using double-layered soft agar cloning assay

An in vitro chemosensitivity test on permanent cell lines from adeno-, epidermoid and small cell carcinoma of the lung was performed using a double-layered soft agar cloning assay. Drugs tested in the present study were Adriamycin, 40497S, Mitomycin C, cis-Dichlorodiammineplatinum, Methotrexate and Vincristine. Adriamycin, 40497S, Mitomycin C and cis-Dichlorodiammineplatinum showed dose-dependent cytotoxity. Methotrexate and Vincristine did not show a significant cytotoxity when the cell lines were exposed for one hour. Differences in chemosensitivity to the six drugs examined among the three cell lines was relatively small e.g. the lethal dose 90% (LD90) of Adriamycin was 0.19mcg/ml in adenocarcinoma, 0.46mcg/ml in epidermoid carcinoma and 0.27mcg/ml in small cell carcinoma. The lack of a difference in chemosensitivity in vitro might be attributed to the fact that the cell lines had been established from bronchogenic carcinomas which were refractory to intensive combination chemotherapy.