Interferons up-regulate with different potency HLA class I antigen expression in M14 human melanoma cell line. Possible interaction with glucocorticoid hormones

The relative potency of interferon a (IFNa), interferon ß (IFNß), and interferon ? (IFN?) in inducing the expression of HLA class I antigens, as well as their capacity to counteract the inhibition induced by glucocorticoid hormones on HLA class I antigen expression, were analysed in the human melanoma cell line M14, both at membrane and at mRNA level. The data obtained indicate that (a) IFN enhance with different potency (IFN?>IFNß>IFNa) the expression of HLA class I antigens in M14 cells, (b) prednisone inhibits HLA class I antigen expresion, (c) glucocorticoid hormones, when associated with IFNa or IFN?, inhibit the HLA class I enhancement induced by IFN alone, and ffinally, (c) the association between 1 µM prednisone or 1 µM deflazacort and IFNß seems to potentiate the enhancing capacity of IFN on the expression of HLA class I molecules at the mRNA level. These findings, if confirmed, might indicate that IFN and glucocorticoid hormones are not mutually exclusive in the management of human melanoma.