ANDROGEN-DEPENDENT GENE-EXPRESSION OF BONE MORPHOGENETIC PROTEIN-7 INMOUSE PROSTATE

BACKGROUND. What is the molecular basis of the osteotrophic action of prostatic metastases? Demineralized bone matrix has the potential to i nduce new bone formation. The identification of bone morphogenetic pro teins (BMPs) as the primary inducers of new bone formation in deminera lized bone matrix has set the stage for studying prostate cancer-bone interrelationships. We have hypothesized that BMPs may be expressed in prostate and may be involved in the osteotrophic actions of metastati c prostate cancer cells. METHODS. Using polymerase chain reaction (PCR )-based quantitation, this study examined the presence of BMPs in mous e prostate and their potential regulation by orchidectomy and androgen replacement. RESULTS. BMP-7 and BMP-4 genes were expressed in mouse p rostate. Quantitative PCR analysis showed that the BMP-7 mRNA level wa s significantly decreased following orchidectomy and increased by test osterone and dihydrotestosterone. Therefore, the BMP-7 mRNA level is a ndrogen-dependent. On the other hand, BMP-4 was expressed constitutive ly in the prostate. CONCLUSIONS. The regulated expression of BMP-7 mRN A in the prostate suggests that BMP-7 may explain in part the stimulat ion of bone formation and osteosclerosis by metastatic prostate adenoc arcinoma. (C) 1998 Wiley-Liss, Inc.