Expression of Vascular Endothelial Growth Factor (VEGF) by cultured human uveal melanoma cells: Effect of Transforming Growth Factor-beta (TGF-BETA)

Purpose. To determine whether human uveal melanoma cells can produce vascular endothelial growth factor (VEGF) and whether VEGF production can be modulated by a cytokine found in the uvea, namely transforming growth factor-beta (TGF-beta). Methods. Five different cultured human uveal melanoma cell lines of differing cellular morphology (2 spindle, 2 epithelioid, 1 mixed), obtained from different tumor sites (4 intraocular, 1 extrascleral/orbital) were used. Cells were grown in serum-free media for 24 hrs in the presence or absence of TGF-beta (1ng/ml). The conditioned media was harvested and assayed for VEGF using an immunoiluorometric technique. Results. All cultured human uveal melanoma cell lines produced VEGF. Among cells derived from intraocular tumor, TGF-beta stimulated VEGF production of epithelioid cells but had no effect on VEGF production of spindle cells. In contrast, TGF-beta inhibited VEGF production of tumor cells derived from an extrascleral orbital site. Conclusions. Cultured human uveal melanoma cells produce VEGF, and TGF-beta can have a variable effect of VEGF production of these cells.