Hepatocyte growth factor (HGF) stimulates tumour invasiveness in papillarycarcinoma of the thyroid

The present study has investigated the functional role of the Met receptor in primary cultures of 20 papillary carcinomas and of normal thyroid cells obtained from the same patients, Normal and tumour cells grew as adherent c ells, formed a confluent monolayer after 10-20 days, had epithelial morphol ogy, and mere immunoreactive for cytokeratin, vimentin, and thyroglobulin, The potential effect of hepatocyte growth factor (HGF) on cell invasiveness was investigated in Boyden chambers, using a nucleopore filter coated with Matrigel as the barrier and HGF as the chemoattractant, Tumour cells of fi ve out of seven cases of papillary carcinoma were more responsive to HGF th an the corresponding normal cells in terms of the number of migrated cells per mm(2). Involvement of the Met receptor in the HGF-induced migratory res ponse was suggested by the observation that the agonistic anti-Met monoclon al antibody (MAb) DO-24 was equally effective, HGF did not affect the proli ferative activity of thyroid cells. Under the same experimental conditions, 10 per cent fetal bovine serum (FBS) induced a two-fold increase in [H-3]t hymidine incorporation into normal cells and tumour cells. These findings a re consistent with the possibility that HGF plays a crucial role in determi ning the invasiveness of tumour cells in papillary carcinoma of the thyroid . Copyright (C) 1999 John Wiley & Sons, Ltd.