Interleukin-1—a major pleiotropic cytokine in tumor–host interactions

Abstract

Interleukin-1 (IL-1) represents a family of two agonistic proteins, IL-1 α and IL-1 β, that are pleiotropic and affect hemopoiesis, inflammation, and immunity. In the context of the producing cell, IL-1 β is solely active in its secreted form, whereas IL-1 α is active as an intracellular precursor, as a membrane-associated cytokine and to a lesser extent as a secreted molecule. IL-1 is abundant at tumor sites, where it may not only affect the growth and invasiveness of malignant cells, but where it may also induce antitumor immunity. Here we review the effects of microenvironmental and tumor cell-associated IL-1 on malignant processes, in experimental tumor models and in cancer patients.