Cytokine regulation of fibroblast growth factor receptor 3 iiib in intestinal epithelial cells. Kanai, Michiyuki, Ian Rosenberg, and Daniel K. Podolsky. Gastrointestinal Unit and Center for the Study of Inflammatory Bowel Disease, Department of Medicine, Massachusetts General Hospital and Harvard Medical School. Boston, MA 02114
APStracts 3:0252G, 1996.
Proliferation and function of the intestinal epithelium is modulated by a range of regulatory peptides including cytokines and peptide growth factors. In order to define mechanisms integrating these regulatory systems, the effects of growth factors and cytokines on the expression of the fibroblast growth factor receptor 3 IIIb expressed on intestinal epithelial cells were examined in Caco-2 cells. Regulated expression of FGFR3 IIIb was associated with acquisition of the differentiated state. Keratinocyte growth factor (KGF), a ligand of another member of the FGFR family enhanced expression of FGFR3 IIIb, while acidic FGF (aFGF), ligand for FGFR3 IIIb itself, had no effect. Epidermal growth factor (EGF) and transforming growth factor b (TGFb) also markedly enhanced FGFR3 IIIb expression in a different temporal pattern. In addition, FGFR3 IIIb expression was increased 10-fold by the cytokine interleukin-2 (IL -2). These studies demonstrate integration between cytokines and growth factor ligand-receptor systems in intestinal epithelial cells.

Received 16 January 1996; accepted in final form 25 October 1996.
APS Manuscript Number G22-6.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996