Abstract
It has been indicated that epithelial-stromal cell interactions are important for maintenance of prostatic growth and functional integrity. To study participation of growth factors and androgen actions in the interactions, we have established a method of primary culture of prostatic cells from mature rats. The method is described for rapid dispersion, simple isolation, and high purification of prostatic epithelial and stromal cells from mature rats. Viable epithelial and stromal cells were prepared by collagenase and trypsin digestion of mature rat prostates. This mixed population of cells was fractionated by low-speed centrifugation to give epithelial and stromal cells. These purified epithelial and stromal cells proliferated in serum-containing medium, and were used for studies on interactions between both cells and effects of dihydrotestosterone (DHT) on cell growth in the primary coculture system.
Our studies revealed that the stromal cells promoted the growth of epithelial cells in the coculture, and the stromal cell conditioned medium also promoted the growth of epithelial cells. This promotion of the epithelial cell growth was independent of epidermal growth factor (EGF), keratinocyte growth factor (KGF) and basic fibroblast growth factor (bFGF). The factors related to the stromal promotion of epithelial cell growth were discussed.
Furthermore, we examined the effects of DHT on prostatic cell growth. Experimental results demonstrated that the epithelial cell growth was reduced by addition of DHT, and this effect of DHT was counteracted by cyproterone acetate (CA) in the coculture. Expression of androgen receptors was shown on the cultured epithelial and stromal cells in this coculture system. These results suggest that this androgen-dependent growth of epithelial cells may relate to differentiation in the coculture.
The primary coculture system described in this paper has allowed us to examine the epithelial-stromal interactions and the effect of DHT on these cells cultured either alone or together.
