IL-1 in Colon Inflammation, Colon Carcinogenesis and Invasiveness of Colon Cancer.

Interleukin-1 (IL-1) is a major "alarm" upstream pro-inflammatory cytokine that mainly acts by inducing cascades of cytokine and inflammation-promoting mediators. In the tumor arena, IL-1 is produced by both malignant and microenvironmental cells. IL-1α and IL-1β are the major agonists of IL-1, while IL-1Ra is a physiological inhibitor of pre-formed IL-1. IL-1α and IL-1β differ in their compartmentalization and in the producing cells. IL-1β is only active in its inflammasome dependent processed and secreted form and has been considered as the major mediator of inflammation. On the other hand, IL-1α is mainly cell-associated in tissue resident cells, being also active in its precursor form. The role of the IL-1 molecules in the unique microenvironment in the colon is largely unknown. Here, we described the role of IL-1α and IL-1β in colon homeostasis, colon inflammation, colon carcinogenesis and invasiveness of colorectal cancer. Understanding of the integrative role of IL-1α and IL-1β in these processes will facilitate the application of novel IL-1 modulating approaches.