Interleukin 1 (IL-1)-dependent melanoma hepatic metastasis in vivo; increased endothelial adherence by L-1-induced mannose receptors and growth factor production in vitro

The growth of cancer cells in inflammatory tissue is often observed. This can be the result of favorable conditions for endothelial cell adherence and/or increased production of local growth factors. The role of the proinflammatory cytokine interleukin 1 (IL-1) in the prometastatic and growth-promoting environment of inflammation was studied in vivo, and the mechanism of cytokine action was studied in vitro as well. Systemic inflammation was induced by the intravenous injection of IL- beta 3 or lipopolysaccharide (LPS), and the hepatic metastasizing ability of B16 melanoma (B16) cells following intrasplenic injection was studied. IL-1 receptor blockade was accomplished with the use of the IL-1 receptor antagonist (IL-1Ra). In vitro, IL-1Ra was used to assess the mechanism for prometastasis and growth promotion of cultured hepatic sinusoidal endothelium stimulated with LPS. There was a statistically significant (P