RESUMO
This work studies the effects of dihydrotestosterone (DHT) and epidermal growth factor (EGF) on the growth, morphology and phenotype characterisation of the U285 line obtained from human prostate hyperplastic tissue. Modifications of growth rate induced by these two substances have been evaluated by means of the neutral red assay formulated by Borenfreund and Puerner (1985) as well as by means of Kenacid blue assay described by Knox et al. (1986), culturing cells for 24, 48 and 72 hr with scalar doses of DHT (0.5, 1, 2, 5, 10 microM) and EGF (5, 10, 20, 100 ng/ml). An optical microscope connected to a computer aided system and a scanning electron microscope were used to monitor morphological changes induced by DHT and EGF. The immunophenotype characterisation of the treated and control cells was carried out by using a monoclonal antibody panel. Our results show that the expression of anti-cytokeratin 5+6+18, anti-cytokeratin 8+18+19 and anti-proline-4-hydroxylase antibodies varied in relation to the type of treatment undergone by the cells. Moreover, exogenous DHT does provoke a flattening of the U285 cells without modifying their rate of growth, while EGF both shortens the lag phase reactivating the quiescent cells and regulates the subsequent log growth phase, thus causing no cellular overgrowth.