DEFINED MEDIUM FOR NORMAL ADULT HUMAN PROSTATIC STROMAL CELLS

Stromal-epithelial interactions are pivotal in many aspects of prostat ic biology. A defined culture system is critical for the investigation of factors that regulate the growth and differentiation of human pros tatic stromal cells. We have identified conditions which promote strom al cell attachment and proliferation in serum-free medium. MCDB 201, o riginally developed for the clonal growth of chick embryo fibroblasts, proved to be a superior basal medium of those that we tested. Supplem entation of MCDB 201 with basic fibroblast growth factor (FGF), insuli n-like growth factor (IGF), and platelet-derived growth factor (PDGF) permitted attachment and exponential growth of cells throughout a 7-d period with an initial inoculum as low as 10(3) cells per well of a 96 -well microtiter dish. Using these assay conditions, we subsequently v erified that basic FGF and IGF, but not PDGF. were required for optima l growth. No activity was found for heparin, transferrin, or the andro gen R1881. Epidermal growth factor (EGF) didn't stimulate growth when added to medium containing basic FGF and IGF, but was moderately stimu latory when added to basal medium alone. Cholera toxin inhibited growt h. This simple and efficient culture medium provides a suitable assay system for more extensive studies of growth regulation and differentia tion of human prostatic stromal cells, and will provide the basis for future development of a defined medium that supports clonal growth. Ch aracterization of stromal-epithelial interactions will be facilitated by the use of this defined culture system for stromal cells in conjunc tion with the serum-free culture systems previously developed for huma n prostatic epithelial cells.