We studied the effect of fotemustine (FM) on the expression of several melanoma-associated antigens (MAA) and HLA antigens defined by a panel of seven monoclonal antibodies (mabs). We also looked for the effect of the culture conditions on the antigen expression. We used eight established melanoma cell lines, grown as monolayers in (a) modified Leibowitz L15 medium for 0, 48, 96 h; (b) with 12.8 μg/ml fotemustine for 48 h; (c) with 12.8 μg/ml fotemustine for 48 h followed by incubation with modified Leibowitz L15 medium for another 48 h. Incubation of melanoma cell lines for 48 or 96 h in growth medium (a) resulted in a modest upregulation of the trans-ferrin receptor (TFR), the very late antigen 2 (VLA-2), and the intercellular adhesion molecule 1 (ICAM-1) in the majority of our cell lines. Following the addition of FM (b) no relevant change in the antigen expression was observed during continuous incubation for 48 h. However, an additional incubation of the FM-treated melanoma cells for another 48 h in FM-free medium (c) showed a striking upregulation of TFR, VLA-2 andICAM-1. Furthermore, the nuclear proliferation-associated antigen detected by Ki67 was upregulated markedly only in the presence of at least 80% HLA-DR-positive cell
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