We investigated the influence of interferons α, β, and γ (IFN-α, -β, and -γ) on the production of basic fibroblast growth factor (bFGF) by human renal carcinoma cells. The human renal carcinoma cell metastatic line SN12PM6 was established in culture from a lung metastasis and SN12PM6-resistant cells were selected in vitro for resistance to the antiproliferative effects of IFN-α or IFN-β. IFN-α and IFN-β, but not IFN-γ, down-regulated the expression of bFGF at the mRNA and protein levels by a mechanism independent of their antiproliferative effects. Downregulation of bFGF required a long exposure (>4 days) of cells to low concentrations (> 10 units/ml) of IFN-α or IFN-β. The withdrawal of IFN-α or IFN-β from the medium permitted SN12PM6-resistant cells to resume production of bFGF. The incubation of human bladder, prostate, colon, and breast carcinoma cells with noncytostatic concentrations of IFN-α or IFN-β also produced down-regulation of bFGF production.
|Number of pages
|Proceedings of the National Academy of Sciences of the United States of America
|Published - 9 May 1995