HORMONAL-REGULATION OF THE ANDROGEN RECEPTOR EXPRESSION IN HUMAN PROSTATIC CELLS IN CULTURE

The regulation of the androgen receptor (AR) expression was studied us ing immunocytochemical and Western blot techniques on separate culture s of epithelial cells (PNT2) and fibroblasts of human prostate. In bot h cell types, immunocytochemistry revealed both nuclear and cytoplasmi c staining. Treatment with DHT (5 x 10(-9) M) increased both the inten sity of nuclear staining and the number of cells stained. The increase , observed after DHT treatment was markedly decreased by cyproterone a cetate (5 x 10(-7) M), confirming a direct action of DHT via the AR. T his autoregulation of AR was confirmed by Western blot, and seems to i nvolve transcription and protein synthesis, since it was suppressed by actinomycin D and cycloheximide. In fibroblasts, known to contain an estrogen receptor, estradiol treatment (5 x 10(-7) M) also increases t he AR immunostaining. In addition, coculture studies show that epithel ial cells require the presence of fibroblasts for optimal expression o f the AR. These results demonstrate that prostate epithelial cells and fibroblasts have retained in culture, an hormonal sensitivity correla ted with the presence of specific receptors and can serve as a model f or the study of hormone action in this tissue in normal or pathologica l conditions. (C) 1998 Elsevier Science Ltd. All rights reserved.