Selective interactions between prostate fibroblast and epithelial cells in co-culture maintain the BPH phenotype.

Paracrine interactions between primary cultured prostate epithelial cells and stromal fibroblasts were investigated in relation to morphology, growth, androgen sensitivity and secretory activities using co-cultures in which the two populations were separated by a microporous membrane. In this new model system, both cell types maintained several aspects of the differentiated phenotype including the capacity to express 5alpha-reductase iso-enzymes and androgen receptors, to respond to androgens and to secrete prostate-specific antigen by the epithelial cells. Morphological studies demonstrated that the cells grown in co-culture exhibited round nuclei, tonofibrils and microvilli in epithelial cells and elongated nuclei, large amounts of Golgi apparatus and cilia in the fibroblasts, all indicative of the differentiated state. The co-culture system highlights the importance of the metabolic co-operation between prostate fibroblast and epithelial cells for preserving the phenotypic characteristics associated with the human prostate in vivo.