IMMUNOCYTOCHEMICAL COMPARISON OF CULTURED NORMAL EPITHELIAL PROSTATICCELLS WITH PROSTATIC TISSUE-SECTIONS

By analyzing a culture system of human prostatic epithelial cells (HPE C) and human prostatic fibroblasts (HPF) for expression of several det erminants by immunocytochemistry, we have shown that long-term culture s are able to preserve the phenotypic characteristics of the normal ti ssue from which they are derived. The cytoskeletal elements, prostate- specific proteins, and steroid receptor profiles were compared to thos e of prostatic epithelium and stroma in situ. When cultured in low ser um and low calcium medium, the adult HPEC grew as two layers of cells, the upper one of which retained the differentiation characteristics o bserved in the luminal fraction of normal prostatic epithelium. This c ell type is the likely origin of prostatic neoplasia, with expression of CK8, 18, and 19 but not CK14. Androgen receptors, prostatic-specifi c antigen, and prostatic acid phosphatase are also expressed in vitro but at lower level than in situ. The lower cell layer expressed most o f the same determinants but at a much lower level, suggestive of a ste m-cell type. The HPF cultured in RPMI serum supplemented media retaine d the stromal pattern of the cells observed in situ. Culture systems w hich conserve the characteristics of their normal counterparts in vivo should provide useful models for studying in vitro genetic and epigen etic factors associated with differentiation and proliferation, but al so with tumorigenic progression in the prostatic gland. (C) 1994 Acade mic Press, Inc.