IDENTIFICATION OF PROLIFERATING HUMAN ANTERIOR-PITUITARY ADENOMA CELLS IN-VITRO

A method to determine whether dispersed human anterior pituitary adeno ma cells proliferate in mixed culture was developed. Fifteen pituitary adenomas were dispersed enzymatically to single cells, following whic h twelve were double immunostained after eight days. Proliferating cel ls were identified immunologically following one hour of bromo-deoxyur idine incorporation. Adenoma cells were subsequently identified with a n anti-neuron-specific enolase antibody system. A time course of bromo deoxyuridine labelling was performed on three nonfunctional adenomas o ver a four day period, with bromo-deoxyuridine being added to cultures at one hour, 24 hours and four days prior to immunostaining. Double i mmunolabelled cells were unambiguously identified by a dark brown nucl eus surrounded by red cytoplasm. Eight out of 12 pituitary adenomas (t wo prolactinomas, three nonfunctional, three growth hormone secreting) showed an increased bromo-deoxyuridine labelling index (range 0.1%-1. 4%). Bromodeoxyuridine incorporation over four days showed an increase in bromo-deoxyuridine from 0.02%, 0.03% and 3.3% at one hour to 10.1% , 1.3% and 5.0% at four days, respectively, but evidence of mitosis wa s scant This study shows that pituitary adenomas may proliferate in vi tro and that this double immunostaining method may be used as an in vi tro proliferation assay in a mixed cell population.