Responsiveness to interferon treatment of human melanoma cells correlates to immunophenotype

Clinical trials with interferon (INF) treatment in patients with advanced metastatic melanoma have met with limited success, suggesting that only a small subgroup of patients with melanoma is sensitive to INF therapy. For therapeutic strategies, it would be of great value to discriminate and define markers related to the anti-proliferative effects of INF. In the present study, we report on the in vitro growth inhibitory effects of INF in six human melanoma cell lines; this is associated with a modulation of cell surface markers. The responsiveness of human melanoma cell lines in vitro to INF-alpha shows a good correlation with a specific immunophenotype (TA99-/EGF-R+ or HLA-DR+). No marker correlated with sensitivity or resistance to INF-beta or INF-gamma. This is the first report identifying cell surface markers of human melanoma cells which might have a predictive value for the clinical response to INF-alpha.