Immunohistochemical Analysis of Interleukin-1 Alpha, Its Type I Receptor and Antagonist in Keratocystic Odontogenic Tumors

Background: Interleukin-1 alpha (IL-1 alpha) is thought to play a crucial role in the growth of keratocystic odontogenic tumors (KCOTs) in the jaw. The function of IL-1 alpha is regulated by the local levels of IL-1 alpha, its receptor and receptor antagonist (IL-1Ra) in tissues. In this study, the expression of these proteins was investigated both before and after marsupialization in KCOTs.

Methods: The expression of IL-1 alpha, IL-1 receptor type I (IL-1RI) and IL-1Ra was detected immunohistochemically in 10 specimens of KCOTs.

Results: IL-1 alpha was intensively expressed throughout the epithelium in all cases, while mild expression of IL-1 alpha was detected in the subepithelial layer endothelial cells and fibroblasts. Mild or intensive immunoreactivity for IL-1RI was also observed in the epithelial cells in all cases, and in the endothelial cells and fibroblasts in five cases respectively. The expression of IL-1Ra was detected in the epithelial cells in five cases, and in the endothelial cells and fibroblasts in three cases. After marsupialization, the immunoreactivity for IL-1 alpha and IL-1RI in the epithelial cells decreased, while the immunoreactivity for IL-1Ra in the epithelial cells increased. However, the immunoreactivity for IL-1RI and IL-1Ra in endothelial cells and fibroblasts did not change significantly.

Conclusion: The effects of IL-1 alpha on the epithelial cells might be downregulated after marsupialization by changing the expression levels of IL-1 alpha, IL-1RI and IL-1Ra in the epithelium of KCOTs.