Effects of Epidermal Growth Factor on the Growth of Human Uveal Melanoma Cells and Uveal Melanocytes in Vitro

Abstract

Purpose: It has been reported that epidermal growth factor receptors (EGFR) present in some uveal melanoma specimens and cell lines. However, the validation of these EGFR is functional by testing the response of melanoma cells to exogenous EGF has not been reported. The purposes of this study was to study the effects of epithelial growth factor (EGF) on the growth of cultured human uveal melanocytes and uveal melanoma cells to document the presence of functional EGFR in uveal melanoma cells. Methods: Immortal human choroidal melanoma cell line (TP31) from surgical specimen from primary choroidal melanoma was used. Human uveal melanocytes were isolated and cultured from donor eyes. Early passages of three cell lines of uveal melanocytes and this cell uveal melanoma cell line were plated separately into multi-well plates and cultured. EGF was added to the culture medium at various concentrations. Each group was performed in triplicate. Cells cultured with the culture medium without EGF were used as the controls. After 6 days, cells were detached and counted. Results: EGF significantly stimulated the growth of uveal melanoma cells in a dose dependent manner from 1-100 ng/ml. The cell number of EGF treated groups (100 ng/ml) was 151±11% of the controls (p＜0.01). EGF did not have any significant effect on the growth of uveal melanocytes at the concentration from 1-100 ng/ml (p＞0.05). Conclusion: EGF stimulates the growth of uveal melanoma cells but not normal uveal melanocytes. This indicates that functional EGFR present in uveal melanoma cells. This may be one of the factors that lead to unlimited growth of uveal melanoma cells in vivo.