MORPHOLOGICAL CHARACTERIZATION OF HUMAN O CULAR MELANOMA CELL-LINES

Several cell lines have been derived from an ocular melanoma obtained from an enucleated patient. Three cell types are observed during the t ime in culture of all the cell lines under study. Two of them have epi thelial and spindle shape respectively. A third cell type, having a sp heroidal shape, is formed from spindle cells and may be transformed in to epithelial cells upon re-seeding. Further experiments showed that t he same cell may change of shape following the cycle : spheroidal --> epithelial --> fusiform --> spheroidal. Scanning microscopy shows the coexistence of the three cell shapes in the same culture and the prese nce of several filaments and processes protruding at the surface of th e cells. Transmission electron microscopy shows that the cell lines, i n general, contain melanosomes empty or fairly pigmented and several f ilaments and microtubules. The presence of melanin may be stimulated b y seeding of melanoma cells over a ''feeder layer'' of fibroblasts.