EXPRESSION OF INTERLEUKIN-1 IN HUMAN PHEOCHROMOCYTOMA

Cytokines and in particular interleukin 1 (IL-1) play a role in the mi cro-environment of various tumors. In addition, it is well established that IL-l. is a neurotrophic, angiogenetic and fibrogenetic factor. U sing in situ hybridization we analyzed the expression of endogenous IL -l in human pheochromocytoma (PCC). With the help of specific antibodi es to B- and T-cells, macrophages, and neuroendocrine cell antigens, w e characterized the distribution and localization of various cell type s in human PCC. The combination of immunohistochemistry and in situ hy bridization was eminently suited to defining the exact cellular source of IL-l expression. In situ hybridization and immunostaining revealed that IL-1 mRNA was located primarily in the tumor cell itself. IL-1 m ay therefore constitute an important paracrine/autocrine factor in neu roendocrine tumors. (C) 1996, Editrice Kurtis