Establishment, characterization, and response to cytotoxic and radiation treatment of three human melanoma cell lines.

Three human melanoma cell lines were derived from tumor specimens and established in culture. CAL 1 originated from a bone marrow metastasis and CAL 4 and CAL 7 were derived from solid tumor fragments. CAL 1 and CAL 7 were cloned before establishment. Ultrastructural and chromosome analysis were carried out along with the response to nine chemotherapeutic agents at various concentrations. Survival curves after irradiation were also plotted. The uncloned cell line, CAL 4, displayed some differences from the other two cell lines as regards ploidy and response to chemotherapy. Greater spread of chromosome numbers were observed with this cell line, which contained both hypoploid and a hyperploid modal numbers. All three cell lines showed a relatively high extrapolation number after irradiation, suggesting that inherent cellular properties may be partly responsible for the clinical radioresistance of malignant melanomas.