Interleukin 1 (IL-1)-Dependent Melanoma Hepatic Metastasis In Vivo; Increased Endothelial Adherence by IL-1-Induced Mannose Receptors and Growth Factor Production In Vitro

Background 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. Purpose 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. Methods Systemic inflammation was induced by the intravenous injection of IL-1β 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. Results There was a statistically significant (P