Expression of bone morphogenetic protein-7 (BMP-7) in human prostate

BACKGROUND It is known that BMP is a factor that strongly induces bone formation in muscle tissue. However, the expression of BMP‐7 is not detected in normal bone tissues. Recently, we reported that the level of BMP‐7 expression was significantly higher in metastatic bone lesions than in normal bone and that the high expression of BMP‐7 in metastatic bone lesions was related to osteoblastic metastasis. The aim of this study was to investigate the level of BMP‐7 gene expression in normal prostate glandular tissues, newly diagnosed prostate cancer tissues, and local recurrent prostate cancer tissues. METHODS Total RNA was extracted from 23 samples of normal prostate glandular tissues, 28 samples of newly diagnosed prostate cancer tissues, and 23 samples of local recurrent prostate cancer tissues. We also examined the expression of BMP‐7 in human prostatic epithelial cells (HPECs) under conditions of androgen replacement. After reverse transcription of the RNA samples, the expression of BMP‐7 was measured by real‐time quantitative polymerase chain reaction (PCR). Glyceraldehyde phosphate dehydrogenase (GAPDH) was used as an internal standard. RESULTS The level of BMP‐7 expression was highest in the normal prostate glandular tissue (P