Expression of Caveolin-1 in Human Cutaneous and Uveal Melanoma Cells

Caveolin-1 can act as a tumour promoter or suppressor depending on the cancer type and stage. In melanoma, information available concerning its expression is ambiguous. In this study, we investigated caveolin-1 mRNA and protein expression levels in human melanoma cell lines of different origin and progression stages. Metastatic cutaneous (WM-266-4, A375), primary cutaneous (WM-115, IGR-39) and primary uveal (mel-202, 92-1) cells were used for quantitative RT-PCR, Western blotting and confocal microscopy. We observed significantly higher expression of caveolin-1 mRNA in cutaneous than in uveal melanoma cells. In accordance, immunostaining of caveolin-1 was stronger in cutaneous cell extracts, while protein bands of uveal origin displayed weak signals. Finally, we detected differences in the caveolin-1 subcellular pattern of distribution between primary and metastatic cells. Overall, this is the first demonstration of caveolin-1 expression in human primary uveal melanoma cell lines and observation that the origin of cells (uveal/cutaneous) has an impact when considering the utility of caveolin-1 as a melanoma cell marker.