Objectives Five-alpha reductase inhibitors (5ARIs) are known as chemopreventive agents in prostate cancer with a risk of high-grade disease. This study evaluated the effects of 5ARI on androgen receptor (AR) and proteins involved in prostate cell growth such as HOXB13 expression in human prostate tissue and LNCaP prostate cancer cells. Materials and Methods We retrospectively selected 21 patients who underwent TURP between March 2007 and February 2010 for previously confirmed BPH by prostate biopsy. They were grouped into control (group 1, n = 9) and 5ARI treatment (group 2, n = 12) before TURP. AR and HOXB13 expression in prostate tissue was evaluated by immunohistochemical staining. We tested the effect of 5ARI on the expression of AR, prostate specific antigen (PSA) and HOXB13 in LNCaP cells. Cells were assessed by Western blot analysis, MTT in vitro proliferation assay, and ELISA. Results: Group 2 showed stronger reactivity for AR and HOXB13 than those of the group 1. MTT assay showed death of LNCaP cells at 25uM of 5ARI. At the same time, ELISA assay for PSA showed that 5ARI inhibited secretion of PSA in LNCaP cells. Western blot analysis showed that 5ARI did not greatly alter AR expression but it stimulated the expression of HOXB13. Conclusions These results demonstrated that 5ARI influences AR and HOXB13 expression in both LNCaP cells and human prostate tissue. In order to use 5ARI in chemoprevention of prostate cancer, we still need to clarify the influence of 5ARI in ARs and oncogenic proteins and its regulation pathway.

PURPOSE: Preexisting bone loss in men with prostate cancer is an important issue due to the accelerated bone loss during androgen deprivation therapy (ADT). In addition, a high prostate-specific antigen (PSA) level has been reported to be related to bone metabolism. This study assessed the factors associated with osteoporosis in Korean men with non-metastatic prostate cancer before undergoing ADT. MATERIAL AND METHODS: The study enrolled patients admitted for a prostate biopsy because of a high PSA or palpable nodule on a digital rectal examination. We divided the patients (n = 172) according to the results of the biopsy: group I, non-metastatic prostate cancer (n = 42) and group II, benign prostatic hypertrophy (BPH; n = 130). The lumbar bone mineral density (BMD) was evaluated using quantitative computed tomography. The demographic, health status, lifestyle, body mass index (BMI), serum testosterone concentration, and disease variables in prostate cancer (Gleason score, clinical stage, and PSA) were analyzed prospectively to determine their effect on the BMD. RESULTS: The estimated mean T-score was higher in group I than in group II (-1.96 ± 3.35 vs. -2.66 ± 3.20), but without statistic significance (p = 0.235). The significant factors correlated with BMD in group I were a high serum PSA (ß = -0.346, p = 0.010) and low BMI (ß = 0.345, p = 0.014) in the multiple linear regression model. Also old age (r = -0.481, p = 0.001), a high serum PSA (r = -0.571, p < 0.001), low BMI (r = 0.598, p < 0.001), and a high Gleason’s score (r = -0.319, p = 0.040) were the factors related to BMD in the correlation. The significant factors correlated with BMD in group II were old age (ß = -0.324, p = 0.001) and BMI (ß = 0.143, p = 0.014) in the multiple linear regression model. CONCLUSIONS: The risk factors for osteoporosis in men with prostate cancer include a low BMI, and elevated serum PSA. Monitoring BMD from the outset of ADT is a logical first step in the clinical strategy to avoid or minimize potential bone-related complications in these patients.