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 alpha (IFN alpha). interferon beta (IFN beta). and interferon gamma (IFN gamma) in inducing the expressio n 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 e nhance with different potency (IFN gamma > IFN beta > IFN alpha the ex pression of HLA class I antigens in M14 cells. (b) prednisone inhibits HLA class I antigen expression. (c) glucocorticoid hormones. when ass ociated with IFN alpha or IFN gamma inhibit the HLA class I enhancemen t induced by IFN alone. and. finaIly. (c) the association between 1 mu M prednisone or 1 mu M deflazacort and IFN beta seems to potentiate t he enhancing capacity of IFN on the expression of HLA class I molecule s at the mRNA level. These findings if confirmed might indicate that I FN and glucocorticoid hormones are not mutually exclusive in the manag ement of human melanoma.