Establishment and characterization of a cell line (DEOC-1) originating from a human malignant melanoma of the skin

A new human malignant melanoma cell line, designated DEOC-1, was established from the heel lesion of a 59-year-old man. This cell line has grown well for 84 months. The monolayer, cultured cells are polygonal in shape, appear to be spindle-shaped cells or multipolar cells, and have a tendency to pile up without contact inhibition. The cells are aneuploid, and the modal chromosomal number is in the hyper-triploid range. The cells were transplanted into the subcutis of SCID mice and produced tumors resembling the original tumor. The DEOC-1 cells (1 × 10 6 /5 mL) produced 5-S-cysteinyldopa (5-S-CD). The cells were not sensitive in vitro to any anticancer drug currently used for the treatment of malignant melanoma. Increases in both the protein and the transcriptional levels (mRNA) of multidrug resistance-related genes (multidrug resistance gene 1, multidrug resistance-associated protein 1 and lung resistance-related protein) were observed in DEOC-1 cells. The DEOC-1 cells are well characterized and are a very useful material for basic research of malignant melanoma.