HEPATOCYTE GROWTH-FACTOR STIMULATES FETAL GASTRIC EPITHELIAL-CELL GROWTH IN-VITRO

Background. The growth and development of the fetal gastrointestinal t ract is likely mediated, in part, by peptide growth factors. We compar ed the mitogenic effects of graded doses of hepatocyte growth factor ( HGF) to epidermal growth factor (EGF), transforming growth factor-alph a (TGF-alpha), and insulin-like growth factor-1 (IGF-1) on fetal rabbi t gastric epithelial cells. Materials and Methods. Fetal rabbit gastri c epithelial cells were purified by mechanical dissociation and select ed culture and grown in short-term (24 h) and long-term (12 days) cult ure. Stimulation of fetal gastric epithelial cell growth in response t o individual peptide growth factors was measured by [H-3]thymidine inc orporation and cell counting. Results. In short-term culture, HGF stim ulated [H-3]thymidine incorporation in a dose-dependent manner from a threshold at 10 pM to a maximum at 100 pM. For EGF and TGF-alpha, maxi mal stimulation occurred at 100 pM. For HGF, maximal [H-3]thymidine in corporation was 3.6 +/- 0.7 times basal. For EGF and TGF-alpha, maxima l [H-3]thymidine incorporation was 4.3 +/- 0.4, and 3.6 +/- 0.4 times basal, respectively. For IGF-1, maximal [H-3]thymidine incorporation w as only 70% of the maximal effect observed for the other growth factor s tested. Rabbit amniotic fluid increased [H-3]thymidine uptake in a d ose-dependent manner. In long-term culture, purification to greater th an 90% epithelial cells was attained after 12 days treatment. For HGF, EGF, TGF-alpha, and 20% rabbit amniotic fluid, significant increases in cell number above control (P < 0.05) were observed at 1 nM concentr ations. None of these individual factors, however, increased cell grow th as significantly as that of 10% fetal bovine serum. Conclusions. Ou r results suggest that: (1) HGF stimulates [H-3]thymidine uptake and c ell proliferation in fetal rabbit gastric epithelial cells in vitro, a nd (2) HGF's mitogenic effect on fetal rabbit gastric epithelial cell growth is comparable to that observed for EGF and TGF-alpha, but super ior to the effect observed for IGF-1. (C) 1998 Academic Press.