INDUCTION OF INTERLEUKIN-6 IN THE EPIDERMIS OF MICE IN RESPONSE TO TUMOR-PROMOTING AGENTS

Recent reports imply that. several epidermal cytokines have a function al role in the tumor promotion stage of the multistage carcinogenesis model in mouse dorsal skin. In this report we describe studies to asse ss the role of interleukin-6 (IL-6) in tumor promotion. Promoting, as well as non-promoting, hyperplastic agents were found to induce IL-6, as measured by mRNA expression. Inhibitors of tumor promotion inhibite d tumor-promoter-mediated IL-6 induction, However, when mice were inje cted with a neutralizing antibody specific to murine IL-6, there was n o effect on tumor-promoter-mediated epidermal hyperplasia and dermal i nflammation. These studies suggest that even though IL-6 is produced i n the epidermis following tumor promoter application, it does not modu late epidermal hyperplasia and dermal inflammation. Our findings also stress the importance of assessing, in in vivo studies, the function o f those cytokines suggested by in vitro experiments to have important roles in tumor promotion.