LOCALIZATION OF 1,25-DIHYDROXYVITAMIN D-3 RECEPTOR (VDR) EXPRESSION IN HUMAN PROSTATE

1,25-dihydroxyvitamin D-3 (1,25(OH)(2)D-3) has been found to have a va riety of physiological functions, including effects on growth and diff erentiation in normal and malignant cells. The antiproliferative effec ts of 1,25(OH)(2)D-3 are reported to be mediated through the genomic s ignaling pathway by binding to a specific high affinity receptor prote in, the 1,25-dihydroxyvitamin D-3 receptor (VDR). VDR has been localiz ed in a variety of tissues, but little is known about VDR distribution in human prostate. In this study, we raised an antibody against a syn thetic peptide corresponding to amino acids 10-24 of human vitamin D r eceptor. The sequence selected for immunization is identical in human, rat and mouse VDR. Based on this antibody, we developed an immunohist ochemical method suitable for studing VDR expression in paraffin-embed ded tissue. The immunohistochemical staining was verified using classi cal target organs for vitamin D (kidney, intestine, skin). With this m ethod, we studied VDR localization on paraffin-embedded human prostati c tissue obtained from 8 patients undergoing radical prostatectomy for urinary bladder cancer and demonstrate VDR expression in the secretor y epithelial and few stromal cells of human prostate. The nuclear stai ning in the secretory epithelial cells was concentrated near the nucle ar membrane and in discrete foci in the nucleoplasm. This suggests tha t effects of 1,25-dihydroxyvitamin D-3 are mediated through VDR in the se cells. Moreover our result indicates that there are strong variatio ns in VDR expression between prostatic samples. (C) 1998 Elsevier Scie nce Ltd. All rights reserved.