The effect of α and γ interferon on cell growth and histocompatibility antigen expression by human renal carcinoma cells in vitro

Abstract Tumour cells were separated from 19 renal carcinomas and cultured in vitro . The effect of interferon (IFN) α and γ on cell proliferation was measured and compared to the effect of IFN on the expression of class I and class II major histocompatibility complex (MHC) antigens. When tested within the first 14 days of culture, IFN-α inhibited protein synthesis in 12 of 15 and IFN-γ in four of nine tumours. Reduction in cell counts was in parallel. In six tumours the culture period was extended and in all six the effect of IFN-α was lost. Exposure to IFN-α induced or enhanced class I antigen expression in eight of 19 tumours and class II expression in two of 19. The analogous figures for IFN-γ were five and three tumours. In four of five cases where a comparison could be made there was a correlation between the effects of IFN-α on cell proliferation and class I antigen expression. The efficacy of IFN in the treatment of renal carcinomas may thus, in part, result from inhibition of cell proliferation and enhancement of antigen expression.