Antioxidant pattern in uveal melanocytes and melanoma cell cultures

PURPOSE. To investigate the antioxidant status of cultured uveal melanocyte s from patients with uveal melanoma and uveal melanoma cells to characteriz e some of the biochemical properties of these cells in respect to the norma l cutaneous melanocytes. METHODS. The fatty acid pattern of membrane phospholipids, intracellular vi tamin E level, and superoxide dismutase (SOD) and catalase activities were studied in uveal melanocytes (n = 10) and uveal melanoma cell (n = 10) cult ures, by gas chromatography mass spectrometry or by spectrophotometer. RESULTS. Among the uveal melanocyte cultures, two groups were differentiate d, according to catalase activity : group A with catalase values comparable to those of cutaneous ones and higher SOD activity and group B with catala se values 2 SD lower (P < 0.001) and lower SOD activity. Vitamin E concentr ation was not significantly different between melanoma cells and melanocyte s, whereas a significantly higher percentage of polyunsaturated fatty acids was found in melanoma cells and the 13 group of melanocytes (P = 0.022). I n ur cal melanoma cells SOD activity was significantly lower than that dete cted in uveal melanocytes (P < 0.005). CONCLUSIONS. These results show a different pattern of antioxidants in uvea l melanocytes with respect to cutaneous ones, possibly related to the anato mic distribution. However, as in cutaneous melanocytes, two subgroups were identified on the basis of the antioxidant pattern that could be the expres sion of a constitutional increased susceptibility to oxidative stress in so me subjects. Moreover, an imbalance of the antioxidants was observed in mel anoma cells, possibly related to the disease status and progression.