Cell lineage characteristics of human prostatic stromal cells cultured in vitro

BACKGROUND. An in vitro model of prostatic stromal cells suitable for exper imental studies of the pathogenesis of BPH is still lacking. We therefore s tandardized the isolation, cultivation, and characterization of human prost atic stromal cell lineages. METHODS. Stromal cells were isolated from a surgical specimen of BPH. Using antibodies specific for either epithelial or stromal cells of the human pr ostate, the isolated cells were morphologically and immunohistochemically c haracterized. Viability and functional activity were assessed by proliferat ion assays and stimulation experiments. Gene expression was monitored by RT -PCR. RESULTS. In early passages (P8), cells showed a high purity (greater than o r equal to 98%) for stromal markers; about 60% displayed the characteristic s of fibroblasts, and the remaining 40% were classified as smooth muscle ce lls. In late passages (P20), the proportion of muscle cells declined to 10% , Stimulation experiments including basic fibroblast growth factor (bFGF) r esulted in enhanced proliferation, whereas dihydrotestosterone (DHT), estro gen, and flutamide did not influence proliferation. Gene expression studies demonstrated a positive signal for androgen receptor and keratinocyte grow th factor (KGF). CONCLUSIONS. Prostatic stromal cells can be propagated several times and sh ow karyotypic stability for up to 18 subculture experiments. The ratio of m yoid and fibroblastic cells can be used for standardization of cell culture s with stable characteristics. Prostate 43:20-30, 2000. (C) 2000 Wiley-Liss , Inc.