Effects of basic fibroblastic growth factor on the function and proliferation of human clinically non-functional...

The effects of human recombinant basic fibroblastic growth factor (bFGF) on the secretion, viability, proliferation, attachment and morphology of ten dispersed human clinically non-functional (NF) adenomas were examined in vitro. Four clinically NF adenomas secreting FSH and/or LH in vitro were unaffected by 10 nM bFGF over a 4-h period. Over 4 days 10 nM bFGF stimulated LH secretion (66% and 72%, P < 0.01) from two out of seven clinically NF adenomas secreting LH, whilst FSH (three tumours) and alpha-subunit secretion (three tumours) were unaffected. One adenoma co-secreting LH and alpha-subunit and one secreting LH alone were studied over 21 days; LH secretion fell progressively, but the decline was significantly less (P < 0.05) with bFGF (10 nM) treatment after 14 and 21 days in both adenomas, whilst the fall in alpha-subunit secretion was unaffected by bFGF treatment. A 24-h GnRH test performed at the start and end of the 21-day period in one of these tumours showed an increase in both basal and stimulated LH secretion in the bFGF-treated group over control (124%, P < 0.001). There was no effect of bFGF (10 nM) on viability, S-phase proliferation, attachment or morphology of adenoma cells over a 4-day period. These results suggest that bFGF has a role in tumorous LH secretion from these adenomas, but is not mitogenic (at least over 4 days) and is without effect on other parameters of in vitro differentiated function.