Pathology of benign prostatic hyperplasia

Genetically elevated bioavailable testosterone level was associated with the occurrence of benign prostatic hyperplasia

BACKGROUND

Recent studies identified several risk factors of benign prostatic hyperplasia (BPH), including dyslipidemia, type 2 diabetes mellitus, hypertension, and obesity. But they were not so reliable and some studies contradicted with one another. Hence, a reliable method is urgently needed to explore exact factors that facilitated BPH development.

METHODS

The study was based on Mendelian randomization (MR) design. All participants were from the most recent genome-wide association studies (GWAS) with large sample size. The causal associations between nine phenotypes (total testosterone level, bioavailable testosterone level, sex hormone-binding globulin, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, type 2 diabetes mellitus, hyper-tension, and body mass index) and BPH outcome were estimated. Two sample MR, bidirectional MR, and multivariate MR (MVMR) were performed.

RESULTS

Increase in bioavailable testosterone level was able to induce BPH based on nearly all combination methods [beta (95% confidence interval (CI)): 0.20 (0.06-0.34) for inverse variance weighted (IVW)]. The other traits seemed to interact with testosterone level and did not cause BPH generally. Higher triglycerides level was likely to raise bioavailable testosterone level [beta (95% CI): 0.04 (0.01-0.06) for IVW]. In MVMR model, bioavailable testosterone level was still associated with BPH occurrence [beta (95% CI) 0.27 (0.03-0.50) for IVW].

CONCLUSIONS

We for the first time validated the central role of bioavailable testosterone level in the pathogenesis of BPH. The complex associations between other traits and BPH should be further investigated.

The Symptoms of Benign Prostatic Hyperplasia Patients with Stromal-Dominated Hyperplasia Nodules May Be Associated with Prostate Fibrosis

Objective

The aim of the present study was to observe the effect of the stroma proportion in hyperplasia nodules on the clinical symptoms of benign prostatic hyperplasia (BPH) patients and to identify the different genes and pathways in prostatic hyperplasia nodules between patients with epithelial-dominated hyperplasia (EDH) and stromal-dominated hyperplasia (SDH) nodules.

Methods

Sixty-seven BPH patient samples underwent transurethral resection of the prostate (TURP) were collected and retrospectively analyzed. The differences in clinical parameters between the EDH and SDH groups were investigated. Collagen fiber percentage was assessed, and the correlation with clinical parameters was evaluated. mRNA sequencing in hyperplasia nodules of 8 BPH patients was performed, and differentially expressed genes (DEGs) between the EDH and SDH groups were screened. These DEGs were analyzed using GO, KEGG and PPI analysis.

Results

The results showed the IPSS was significantly higher in the SDH group than in the EDH group (p < 0.01). The collagen fiber percentage of BPH nodules was higher in the SDH group than in the EDH group (p < 0.05), and the collagen fiber percentage was positively correlated with the IPSS (r = 0.4058, p = 0.0007). A total of 172 DEGs were obtained, including 63 up-regulated genes and 109 down-regulated genes. GO and KEGG pathway enrichment analyses showed DEGs were mainly enriched in extracellular matrix structural constituents. The top 10 hub genes were associated to the components of extracellular matrix and fibrosis.

Conclusion

These results suggested that the symptoms of BPH patients with SDH nodules may be associated with prostate fibrosis and fibrosis may be a significant contributing factor in BPH/LUTS patients with SDH nodules.

Lipidic extract of whole tomato reduces hyperplasia, oxidative stress and inflammation on testosterone-induced BPH in obese rats

PURPOSE

Tomato is an important source of lycopene, a carotenoid that has been emerging as a natural preventive agent for prostate disease. Moreover, tomato contains other components with a wide range of physiological properties, but their potential beneficial effects on prostatic hyperplasia (PH) during obesity have not been completely established. In this study, we compared the effect of a lipidic extract of tomato saladette (STE) with Serenoa repens (SR) on obese rats with PH.

METHODS

Forty-eight Wistar rats were divided in Control (C) and Obese (Ob) treated without (n = 12) and with (n = 36) testosterone enanthate (TE), once a week for 8 weeks to induce PH. After 4 weeks, SR and STE were administered. Biochemical parameters, oxidative stress markers and inflammatory cytokines production were determined.

RESULTS

TE increased prostate weight and caused prostatic hyperplasia in C group, and these effects were exacerbated by obesity. SR and STE reverted the increase in prostate weight and hyperplasia caused by TE in C and Ob groups. Obesity increased LDL, TGs, NOx and MAD, but decreased HDLc, GSx, SOD and CAT. SR reverted the effects of obesity, but these were significantly reduced and HDLc increased with STE. Obesity and TE increased TNFα, IL-1β and IL-6 levels, but these were partially reverted by STE compared with SR.

CONCLUSIONS

Excess of fat tissue increases the alterations by PH. STE diminishes these alterations compared with SR, suggesting its beneficial effect to improve prostate function. Whole tomato lipid extract could serve as sole therapy or as an adjunct to pharmacological treatment for PH.

Cleistanthins A and B Ameliorate Testosterone-Induced Benign Prostatic Hyperplasia in Castrated Rats by Regulating Apoptosis and Cell Differentiation

Background The aging male population is at higher risk for benign prostatic hyperplasia (BPH) wherein increased proliferation of stromal and epithelial cells of the prostate is observed. In this study, we investigated the effect of cleistanthins A and B on the inhibition of testosterone-induced BPH in castrated rats. Methodology Male Wistar rats were divided into eight groups (n = 6) and surgical castration was performed. BPH was induced by the administration of testosterone propionate in corn oil at 5 mg/kg for four weeks. The control group received corn oil, and the model group received testosterone propionate. The standard treatment group received finasteride orally along with testosterone. Cleistanthins A and B at 0.3, 1, and 3 mg/kg were administered by oral gavage along with testosterone. After four weeks, rats were sacrificed, and prostates were weighed and assessed for histomorphological, inflammatory, apoptotic, and proliferative markers. Results Cleistanthins A and B decreased prostatic enlargement and histopathological abnormalities. Elevated serum dihydrotestosterone levels were lowered significantly in both the cleistanthin A and cleistanthin B groups compared to the BPH model group. Cleistanthins A and B significantly lowered the serum interleukin (IL)-1β and tumor necrosis factor-alpha inflammatory markers in the test groups. Western blot analysis revealed cleistanthin A downregulated the IL-6, signal transducer and activator of transcription 3/cyclin D1 signaling pathway. Both cleistanthins A and B upregulated the apoptotic markers caspase-3 and cleaved caspase-3, whereas the cell proliferation markers cyclin D1 and proliferating cell nuclear antigen were found to be downregulated. Conclusions Both cleistanthins A and B inhibited BPH in a rat model by apoptotic induction and impeded cell proliferation.

6-Paradol Alleviates Testosterone-Induced Benign Prostatic Hyperplasia in Rats by Inhibiting AKT/mTOR Axis

INTRODUCTION

Benign prostatic hyperplasia (BPH) is a common disease among elderly men. Its pharmacological treatment is still unsatisfactory. 6-Paradol (6-PD) is an active metabolite found in many members of the Zingiberaceae family. It was reported to possess anti-proliferative, antioxidant, and anti-inflammatory activities. The present study aimed at exploring the potential of 6-PD to inhibit testosterone-induced BPH in rats as well as the probable underlying mechanism.

METHODS

Male Wistar rats were divided into 6 groups and treated as follows: Group 1 (control group) received vehicles only, Group 2 testosterone only, Groups 3 and 4 received 6-PD (2.5 and 5.0 mg/kg; respectively) and testosterone, and Group 6 received finasteride and testosterone.

RESULTS

Daily treatment of animals with 6-PD at the two dose levels of 2.5 and 5 mg/kg significantly ameliorated a testosterone-induced rise in prostate index and weight. This was confirmed by histological examinations of prostatic tissues that indicated a reduction in the pathological changes as well as inhibition of the rise in glandular epithelial height in 6-PD treated rats. Immunohistochemical investigations showed that 6-PD prevented the up-regulation of cyclin D1 induced by testosterone injections. Further, 6-PD significantly modulated mRNA expression of both Bcl2 and Bax in prostate tissues of testosterone-treated rats in favor of anti-proliferation. It also showed antioxidant activities as evidenced by inhibition of accumulation of malondialdehyde (MDA) and exhaustion of catalase (CAT) activity. In addition, 6-PD displayed significant anti-inflammatory activities as it prevented up-regulation of interleukin-6 (IL-6) and nuclear factor kappa B (NF-κB). Immunoblotting analysis revealed that 6-PD significantly inhibited testosterone-induced activation of AKT and mTOR in prostate tissues.

CONCLUSIONS

6-PD protects against testosterone-induced BPH in rats. This can be attributed, at least partly, to its antiproliferative, antioxidant, and anti-inflammatory properties as well as its ability to inhibit activation of the AKT/mTOR axis.

Phytosterols in hull-less pumpkin seed oil, rich in ∆7-phytosterols, ameliorate benign prostatic hyperplasia by lowing 5α-reductase and regulating balance between cell proliferation and apoptosis in rats

Background

Pumpkin seed oil is widely used to treat benign prostatic hyperplasia (BPH), a common disease in elder men. However, its active components and mechanism have remained to be elucidated.

Objective

The objective of the present study was to investigate the active components of pumpkin seed oil and its mechanism against BPH.

Design

Total phytosterol (TPS) was isolated from hull-less pumpkin (Cucurbita pepo L. var. Styriaca) seed oil and analyzed by gas chromatography/mass spectrometry (GC/MS). Three phytosterols were purified by preparative HPLC (high performance liquid chromatography) and confirmed by NMR (nuclear magnetic resonance). TPS (3.3 mg/kg body weight, 1 mL/day/rat) was administered intragastrically to the testosterone propionate-induced BPH rats for 4 weeks. The structure changes of prostate tissues were assessed by hematoxylin & eosin (H&E) staining. The expression of androgen receptor (AR) and steroid receptor coactivator 1 (SRC-1) was analyzed by immunohistochemistry, while that of 5α-reductase (5AR), apoptosis, or proliferation-related growth factors/proteins was detected by real-time quantitative polymerase chain reaction or western blotting.

Results

The ∆⁷-phytosterols in TPS reached up to 87.64%. Among them, 24β-ethylcholesta-7,22,25-trienol, 24β-ethylcholesta-7,25(27)-dien-3-ol, and ∆⁷-avenasterol were confirmed by NMR. TPS treatment significantly ameliorated the pathological prostate enlargement and restored histopathological alterations of prostate in BPH rats. It effectively suppressed the expressions of 5AR, AR, and coactivator SRC-1. TPS inhibited the expression of proliferation-related growth factor epidermal growth factor, whereas it increased the expressions of apoptosis-related growth factor/gene transforming growth factor-β1. The proliferation-inhibiting effect was achieved by decreasing the ERK (extracellular signal-regulated kinase) phosphorylation, while apoptosis was induced by Caspase 3 activation through JNK (c-Jun N-terminal kinase) and p38 phosphorylation.

Conclusion

TPS from hull-less pumpkin seed oil, with ∆⁷-phytosterols as its main ingredients, is a potential nutraceutical for BPH prevention.

Photothermal therapeutic potency of plasmonic silver nanoparticles for apoptosis and anti-angiogenesis in testosterone induced benign prostate hyperplasia in rats

AIMS

In this study, we used a near-infrared laser (NIR) to increase the potency of silver nanoparticles (AgNPs) to develop a novel, less invasive, and simple photothermal therapy technique for benign prostate hyperplasia (BPH).

MATERIALS AND METHODS

The shape, particle size, and zeta-potential of polyvinylpyrrolidone coated-AgNPs (PVP-AgNPs) were determined using transmission electron microscopy (TEM), Zeta-potential, and Particle size analyzer (ELSZ). To induce BPH, thirty-six male Sprague-Dawley (SD) rats were given intramuscular (i.m) injections of testosterone propionate (TP) at 5 mg/kg body weight (b.w)/day suspended in 0.1 ml of olive oil for 14 days. Photothermal therapy with AgNPs-NIR for 14 days was carried out. Prostate size, prostate index (PI), dihydrotestosterone (DHT), prostate-specific antigen (PSA), gross, hepatic, and renal toxicity, as well as antioxidant activity, apoptosis, and angiogenesis markers in prostatic tissues were measured. Histological examinations of prostates and biocompatibility of NIR-AgNPs on vital organs were also performed.

KEY FINDINGS

The aggregated spherical AgNPs with a mean size of 50-90 nm and a Zeta potential of -53.22 mV displayed high effectiveness in the NIR (532 nm-1 W) region by decreasing prostate size, PI, DHT, and PSA in BPH rats with no signs of gross, hepatic, or renal damage. As compared to alternative therapies, hyperthermia therapy increased antioxidant activities, induced apoptosis, inhibited angiogenesis, reduced histological alterations in the prostates of BPH rats, and improved biocompatibility of the vital organs.

SIGNIFICANCE

The current study demonstrated the effectiveness of plasmonic AgNPs photothermal therapy in the treatment of BPH.

Phosphoproteomics identifies potential downstream targets of the integrin α2β1 inhibitor BTT-3033 in prostate stromal cells

Background

Integrin α2β1 inhibitor BTT-3033 (1-(4-fluorophenyl)-N-methyl-N-[4[[(phenylamino)carbonyl]amino]phenyl]-1H-pyrazole-4-sulfonamide) was recently reported to inhibit neurogenic and thromboxane A2-induced human prostate smooth muscle contraction, and thus represents a target with a different inhibition spectrum than that of α1-blockers in benign prostate hyperplasia (BPH) treatments. Clarifying the underlying mechanisms of the inhibition effects will provide insights into the role of integrin α2β1 in prostate contraction and enable new intracellular targets for smooth muscle contraction to be explored.

Methods

ProteomeHD was used to predict and enrich the top co-regulated proteins of integrin α2 (ITGA2). A phosphoproteomic analysis was conducted on human prostate stromal cells (WPMY-1) treated with 1 or 10 µM of BTT-3033 or solvent for controls. A clustering analysis was conducted to identify the intracellular targets that were inhibited in a dose-dependent manner. Gene ontology (GO) and annotation enrichments were conducted to examine any functional alterations and identify possible downstream targets. A Kinase-substrate enrichment analysis (KSEA) was conducted to identify kinases-substrate relationships.

Results

Enrichments of the actin cytoskeleton and guanosine triphosphatases (GTPases) signaling were predicted from the co-regulated proteins with ITGA2. LIM domain kinases, including LIM domain and actin-binding 1 (LIMA1), zyxin (ZYX), and thyroid receptor-interacting protein 6 (TRIP6), which are functionally associated with focal adhesions and the cytoskeleton, were present in the clusters with dose-dependent phosphorylation inhibition pattern. 15 substrates were dose-dependently inhibited according to the KSEA, including polo-like kinase 1 (PLK1), and GTPases signaling proteins, such as disheveled segment polarity protein 2 (DVL2).

Conclusions

In this study, we proposed that the mechanisms underlying the contractile and proliferative effects of integrin α2β1 are the LIM domain kinases, including the ZYX family, and substrates, including PLK1 and DVL2.

Curcuma oil ameliorates benign prostatic hyperplasia through suppression of the nuclear factor-kappa B signaling pathway in rats

ETHNO PHARMACOLOGICAL RELEVANCE

Curcuma longa L is traditionally used as an anti-inflammatory remedy in Chinese traditional medicine. Curcuma oil (CO), a lipophilic fraction from Curcuma longa L. has been reported to have anti-proliferative, anti-inflammatory and anti-oxidant activities. However, CO has never been investigated for its possible therapeutic effects on benign prostatic hyperplasia (BPH).

AIMS OF THE STUDY

The study is thus to determine the therapeutic effects of curcuma oil on BPH and also the possible mechanism (s) of action.

MATERIALS &METHODS

A BPH-1 cell line and Sprague Dawley (SD) rats were used to establish BPH models in vitro and in vivo, respectively. Rats were treated by CO (2.4, 7.2 mg/kg/i.g.) and finasteride (5 mg/kg/i.g.), respectively. Histological changes were examined by hematoxylin and eosin (H&E) staining. Protein expression was analyzed for 5α-reductase (5AR), dihydrotestosterone (DHT), interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α by ELISA. Ki-67, Caspase-8,-9 and -3 expressions were evaluated via immunohistochemistry (IHC).

RESULTS

CO effectively induced apoptosis in BPH-1 cells. BPH was successfully established by administration of testosterone propionate (TP) in rats, which upregulated both 5α-reductase expression and DHT production. Importantly, TP establishment significantly stimulated the phosphorylation of p65, one subunit of NF-κB, thus led to activation of the NF-κB signaling pathway in prostatic tissues of rats. In turn, the activation of NF-κB pathway induced concomitant upregulation of proinflammatory factors IL-1β, IL-6, TNF-α, and COX-2 and significant increase of the Bcl2/Bax expression ratio for enhanced cell survival, contributing to the initiation and progression of BPH in rats. Notably, CO therapy significantly decreased prostate weight and hyperplasia in BPH-induced animals. Also CO was found to suppress the expression of 5α-reductase and thus the production of DHT, which is essential for the amelioration of BPH. More importantly, CO was shown to suppress the activation of NF-κB pathway through decreasing the expression of phosphorylated p65 and consequently reduced the inflammatory responses and cell survival in prostatic tissues, leading to the inhibition of BPH development in rats.

CONCLUSION

Curcuma oil is very effective for ameliorating BPH in rats. The underlying mechanisms involve in reduced inflammatory responses and cell survival through suppression of the NF-κB signaling pathway by CO in prostatic tissues.

Effect of Nandrolone decanoate induced-oxidative stress on rat testes, prostate, and seminal vesicle: Biochemical, morphometric and histopathological studies

Nandrolone decanoate (Nd) is a highly abused androgenic-anabolic steroid among body builders. Even though it has weak androgenic effects, its prolonged use may have harmful impact on male reproductive system which needs to be evaluated. This study aimed to reinvestigate its possible oxidative stress induced alteration on male rat reproductive system. Twenty-eight male rats were divided into two groups. Nd treated group (n = 18) injected intramuscular with 10 mg/kg body weight once a week for four weeks. While, the control group (n = 10) was injected with physiologic saline by the same route for four weeks. Body weight was recorded for all rats and after animal dissection weight of testes, prostate and seminal vesicles were also recorded. The results showed that the average testicular weight was decreased in treated group compared to the control. The average weights of the prostate and seminal vesicles were increased compared to the control. Morphometric study revealed that in Nd treated group, there was a decrease in the width of seminiferous tubules and the height of spermatogenic cell layer compared to the control. Testicular degeneration was expressed by presence of spermatid giant cells, vacuolation, and degenerated spermatozoa. Tunnel technique showed scattered positive reaction among the spermatogenic cell layers and interstitial cells. Severe alterations of the prostate were expressed by benign prostate hyperplasia and retained secretions. Lipid peroxidation products (malonaldehyde concentration as ng/g of testicular tissue) were increased in treated group compared to the control and suggested the occurrence of oxidative damage. Nd induced severe alterations in the male genital organs were resulted from oxidative stress. It is concluded that the male genital organs are highly sensitive to the anabolic steroids and there is a high extent of reproductive risk associated with the use of AASs.

Overexpression of GDNF and FGF-1 in Canine Benign Prostatic Hyperplasia: Evidence for a Pathogenetic Role of Neural Growth Factor

Benign prostatic hyperplasia (BPH) is common in aged dogs, but the pathogenesis has not been clearly elucidated. A total of 33 male Iranian dogs of mixed breed and in three age groups (under 3 years [n = 10]; 3-6 years [n = 15]; over 6 years [n = 8]), were investigated. BPH was confirmed by ultrasonography and histopathology in 13 cases. The highest prevalence of BPH was in the 3-6 years age group (8/15; 53.3%). Examination of sections of prostate that had been stained with Masson's trichrome revealed that the intensity of stromal smooth muscle cell staining (P <0.05) and the number of fibroblasts (P = 0.002) were significantly increased in BPH compared with normal prostate glands. Prostate cells from dogs with BPH (n = 13) had a significantly higher intensity of cytoplasmic immunolabelling with antibodies against glial cell line-derived neurotrophic factor (GDNF), cytokeratin (CK) AE1/AE3, vimentin, fibroblast growth factor-1 (FGF-1) and prostate-specific antigen (PSA), compared with normal prostate glands (n = 20) (P = 0.001), except for PSA, which was negative in both normal and BPH affected prostates. The overexpression of GDNF and FGF-1 in stromal and epithelial cells of prostate glands of dogs with BPH suggests that GDNF has a paracrine or autocrine role in stimulating cellular proliferation. GDNF overexpression may also play a pathogenetic role in promoting chronic prostatitis and increasing fibrosis and the smooth muscle component of the prostate gland in BPH.

Rauwolfia vomitoria extract suppresses benign prostatic hyperplasia by reducing expression of androgen receptor and 5α-reductase in a rat model

OBJECTIVE

Herbal medicine is an important therapeutic option for benign prostatic hyperplasia (BPH), a common disease in older men that can seriously affect their quality of life. Currently, it is crucial to develop agents with strong efficacy and few side effects. Herein we investigated the effects of the extract of Rauwolfia vomitoria, a shrub grown in West Africa, on BPH.

METHODS

Rats with testosterone-induced BPH were treated with R. vomitoria. Prostates were histologically analyzed by Hematoxylin and eosin staining. Proliferation index and the expression levels of androgen receptor and its associated proteins were quantified through immunohistochemistry and immunoblotting. Androgen receptor target genes were examined by quantitative real-time polymerase chain reaction. The sperm count and body weight of rats were also measured.

RESULTS

The oral administration of R. vomitoria extract significantly reduced the prostate weight and prostate weight index in BPH rats, supported by the decreased thickness of the prostate epithelial layer and increased lumen size. Similar effects were observed in the BPH rats treated with the reference drug, finasteride. R. vomitoria extract significantly reduced the testosterone-induced proliferation markers, including proliferating cell nuclear antigen and cyclin D1, in the prostate glands of BPH rats; it also reduced levels of androgen receptor, its associated protein steroid 5α-reductase 1 and its downstream target genes (FK506-binding protein 5 and matrix metalloproteinase 2). Notably, compared with the finasteride group, R. vomitoria extract did not significantly reduce sperm count.

CONCLUSION

R. vomitoria suppresses testosterone-induced BPH development. Due to its milder side effects, R. vomitoria could be a promising therapeutic agent for BPH.

Evaluation of serum prolidase activity and oxidative stress markers in men with BPH and prostate cancer

Background

Prostate cancer (PCa) and benign prostatic hyperplasia (BPH) are diseases of elderly men and are related to increased oxidative stress (OS). Although prolidase has a role in collagen metabolism, it is also used to evaluate OS in many diseases. However, there is a lack of data about serum prolidase activity (SPA) in prostate cancer. The aim of this study was to evaluate and compare SPA levels in males with BPH and PCa.

Methods

Evaluation was made of a total of 81 men who underwent transrectal ultrasound guided prostate biopsy for a definitive diagnosis due to high PSA levels. Patients were separated into 2 groups as BPH and PCa patients. Pre-biopsy malondialdehyde (MDA), superoxide dismutase (SOD), PSA levels and serum prolidase activities (SPA) were compared between the groups and the correlations of SPA with the other parameters were also investigated in both groups.

Results

BPH was diagnosed in 51 patients and PCa in 30. The mean age of patients was similar in both groups as 63.25 ± 5.81 years in the BPH group 65.30 ± 7.35 years in the PCa group(p:0.081). The median MDA and SOD levels were insignificantly increased in the PCa patients. SPA values were similar in BPH and PCa patients. SPA did not correlate with age, PSA, MDA or SOD levels in either group.

Conclusions

Our study results revealed that serum prolidase activity is similar in BPH and PCa cases and is not correlated with MDA, SOD or PSA levels.

Beneficial effects of lipidic extracts of saladette tomato pomace and Serenoa repens on prostate and bladder health in obese male Wistar rats

BACKGROUND

Obesity is associated with increased risk of a number of serious medical conditions, including urological disorders. This study investigated the effect of lipidic extracts of saladette tomato pomace (STP) and Serenoa repens (SR) on the prostate and bladder in a rat obese model induced by high-carbohydrate diet.

RESULTS

High-sucrose-fed rats showed higher prostate weight as well as increased contractility and stromal and epithelial hyperplasia in the prostate. Treatment with STP and SR improved contractility and diminished hyperplasia and hypertrophy in the prostate. Obese animals also showed impaired bladder contractility, but neither extract reversed this deterioration. In the histological study, a disarray in the process of smooth muscle cell proliferation with non-parallel fibers was observed; interestingly, treatment with STP and SR led to improvement in this derangement.

CONCLUSION

These findings indicated impaired contractility and hyperplasia in the prostate and bladder of obese rats induced by high sucrose. STP and SR could enhance prostate function by reducing contractility and hyperplasia and improve smooth muscle fiber structure and decrease cell proliferation in the bladder, suggesting their possible health-beneficial effects on lower urinary tract symptoms. © 2017 Society of Chemical Industry.

Cynanchum wilfordii Ameliorates Testosterone-Induced Benign Prostatic Hyperplasia by Regulating 5α-Reductase and Androgen Receptor Activities in a Rat Model

Benign prostatic hyperplasia (BPH) is characterized by uncontrolled proliferation of the prostate gland. Cynanchum wilfordii has been reported to improve sexual behavior in male rats. In this study, we investigated the protective effect of an aqueous extract of C. wilfordii (CWW) against BPH development in a testosterone-induced BPH rat model. The rats were divided into the following six groups: sham/vehicle; BPH/vehicle; BPH/finasteride; and three CWW doses (50, 100, and 200 mg/kg). After a 4-week treatment with CWW, the rats were euthanized at scheduled times, and their prostates were weighed, followed by a histopathological examination. Prostate growth inhibition rates in rats administered CWW 50, 100, and 200 mg/kg were 54.5%, 51.8%, and 50.1%, respectively. The BPH/CWW group showed decreased serum testosterone and dihydrotestosterone (DHT) levels compared to the BPH/vehicle group. Furthermore, the BPH/CWW group showed reduced prostate testosterone and DHT levels compared to the BPH/vehicle group. Mechanistically, the reverse transcription-polymerase chain reaction revealed downregulated mRNA expression levels of the androgen receptor, 5α-reductase, and B-cell lymphoma-2 (Bcl-2) in the BPH/CWW200 group compared with those in the testosterone-induced groups. In conclusion, these findings show the effectiveness of CWW in slowing the progression of testosterone-induced BPH in rats.

Comparing Clinical and Economic Outcomes Associated with Early Initiation of Combination Therapy of an Alpha Blocker and Dutasteride or Finasteride in Men with Benign Prostatic Hyperplasia in the United States

BACKGROUND

Benign prostatic hyperplasia (BPH) is a common disease in men that is characterized by lower urinary tract symptoms. Pharmacologic treatment with alpha blockers (ABs) and 5-alpha reductase inhibitors (5ARIs) is recommended to alleviate symptoms, prevent disease progression that can lead to complications, and reduce health care costs.

OBJECTIVE

To compare clinical, economic, and health care resource utilization outcomes among BPH patients treated with early continuous combination AB and 5ARI therapy (dutasteride vs. finasteride) using administrative claims data from the United States.

METHODS

A retrospective analysis of administrative claims data from 2003-2013 was conducted to compare outcomes between patients with claims for early combination therapy with dutasteride + AB and patients with claims for early finasteride + AB. The study population included males aged older than 50 years with at least 1 medical claim with a diagnosis of BPH and pharmacy dispensing for AB and 5ARI therapies. Outcomes included acute urinary retention (AUR), prostate-related surgery, clinical progression, medical and pharmacy costs, and health care resource utilization. Inverse probability of treatment (IPT) weighted Cox proportional hazards, linear, and Poisson regression models were used to assess the association between outcomes and early combination therapy as appropriate.

RESULTS

A total of 2,778 patients were included in the early finasteride + AB treatment cohort, and 4,125 patients were included in the early dutasteride + AB cohort. Dutasteride users were younger than finasteride users (mean age: 64.8 vs. 67.5 years, P < 0.001) and had a greater mean number of urologist visits (10.7 vs. 7.9, P < 0.001) during baseline. After adjusting for confounding using IPT weighting, no statistically significant difference was observed between dutasteride and finasteride for AUR (hazard ratio [HR] = 0.845, 95% CI = 0.660-1.070, P = 0.1643), prostate-related surgery (HR = 0.806, 95% CI = 0.568-1.171, P = 0.2525), and clinical progression (HR = 0.834, 95% CI = 0.663-1.043, P = 0.1122). While dutasteride was associated with higher pharmacy costs per month (adjusted monthly cost difference = $79, 95% CI = $45-$105), total all-cause medical costs were not significantly different between the 2 cohorts (adjusted monthly cost difference = -$44, 95% CI = -$110-$22).

CONCLUSIONS

Clinical and economic outcomes were similar between the early dutasteride + AB and early finasteride + AB cohorts, with no statistically significant differences detected.

DISCLOSURES

Funding for this study was provided by GlaxoSmithKline (HO-14-15325 and AVO110072). Bell and Swensen are employees of GlaxoSmithKline. DerSarkissian, Xiao, Duh, and Lefebvre are employed by Analysis Group, a consulting company that received research grants from GlaxoSmithKline to conduct this study. Study concept and design were contributed by Bell, Swensen, Lefebvre, and Duh. Bell and Duh acquired the data. DerSarkissian and Xiao performed the statistical analysis and interpreted the data along with Lefebvre, Duh, and Bell. DerSarkissian and Bell drafted the manuscript. All authors contributed equally to critically revising the manuscript and providing final approval of the submitted manuscript.

Pharmaceutical evaluation of naftopidil enantiomers: Rat functional assays in vitro and estrogen/androgen induced rat benign prostatic hyperplasia model in vivo

Naftopidil (NAF) is a α_1D/1A adrenoceptor selective drug used for the treatment of both benign prostatic hyperplasia and lower urinary tract symptoms (BPH/LUTS). However, NAF is used as a racemate in clinic. To compare the differences and similarities among two enantiomers and racemate, pharmacological activities were evaluated through rat functional assays in vitro and estrogen/androgen (E/T) induced rat BPH model in vivo. NAF and the two enantiomers showed similar blocking activity on α₁ receptor. S-NAF exhibited more α_1D/1A adrenoceptor subtype selectivity than R-NAF and the racemate. The selectivity ratios pA₂ (α_1D)/pA₂ (α_1B) and pA₂ (α_1A)/pA₂ (α_1B) were 40.7- and 16.2-fold, respectively. NAF and its enantiomers effectively prevented the development of rat prostatic hyperplasia via suppressing the increase of the prostatic wet weight, visually. The quantitative analysis of the relative acinus volume, relative stroma volume, relative epithelial volume, epithelial height and expression of proliferating cell nuclear antigen (PCNA) and α-smooth muscle actin (α-SMA) were carried out. S-NAF showed an advantage on the effect of inhibiting prostate wet weight and stroma volume over R-NAF and racemate NAF (P<0.05). Nevertheless, no other significant difference was observed between these two enantiomers. In conclusion, both R-NAF and S-NAF not only relax prostate muscle but also inhibit the prostate growth, thus relieve BPH.

Differences in the cellular composition of small versus large uterine fibroids

Uterine fibroids are clonally derived from a single cell; however, despite being monoclonal, the cellular phenotypes that make up uterine fibroids are heterogeneous consisting of predominantly smooth muscle cells (SMC) and fibroblasts. This raises the question as to when clonal cell differentiation occurs during fibroid development, and does this information provide clues about possible mechanisms regulating the growth process that leads to fibroids of symptom-causing size? This study investigated the differences in the cellular composition of fibroids by immunohistochemistry (IHC). A tissue microarray (n = 21 hysterectomy cases) was used for the investigation of large uterine fibroids and normal myometrium. An investigation of small fibroids (≤ 5mm) used a separate group of samples (n = 7 hysterectomy cases, total of n = 17 fibroids). A panel of cell phenotypic markers was selected based on our previous in situ investigations and included aldehyde dehydrogenase 1 (ALDH1A1) and vimentin for different fibroblast sub-populations, smooth muscle actin (SMA) as a marker for SMCs, CD31 for endothelial cells and CD45 for leucocytes. Proliferating cell nuclear antigen (PCNA) was also studied to identify proliferating cells. The cellular composition of small fibroids differs significantly from large fibroids. Small fibroids are more cellular (increased cells/mm(2)) than large fibroids, have more blood vessels and also have a higher ratio of SMC to fibroblasts than large fibroids. Large fibroids have more cell proliferation (measured by PCNA) and fewer leucocytes (measured by CD45) than adjacent myometrium, whereas small fibroids are less proliferative and have similar number of leucocytes to myometrium. Different cellular composition between fibroids of different sizes may provide important clues as to the mechanisms that drive fibroid growth.

Benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH), which causes lower urinary tract symptoms (LUTS), is a common diagnosis among the ageing male population with increasing prevalence. Many risks factors, both modifiable and non-modifiable, can increase the risk of development and progression of BPH and LUTS. The symptoms can be obstructive (resulting in urinary hesitancy, weak stream, straining or prolonged voiding) or irritative (resulting in increased urinary frequency and urgency, nocturia, urge incontinence and reduced voiding volumes), or can affect the patient after micturition (for example, postvoid dribble or incomplete emptying). BPH occurs when both stromal and epithelial cells of the prostate in the transitional zone proliferate by processes that are thought to be influenced by inflammation and sex hormones, causing prostate enlargement. Patients with LUTS undergo several key diagnostic investigations before being diagnosed with BPH. Treatment options for men with BPH start at watchful waiting and progress through medical to surgical interventions. For the majority of patients, the starting point on the treatment pathway will be dictated by their symptoms and degree of bother.

Peripheral mononuclear leukocyte DNA damage, plasma prolidase activity, and oxidative status in patients with benign prostatic hyperplasia

OBJECTIVES

Prolidase plays a major role in collagen turnover, matrix remodeling, and cell growth. Benign prostatic hyperplasia (BPH) may be associated with an increased extracellular matrix deposition. Therefore, the present study was designed to investigate the plasma prolidase activity, oxidative status, and peripheral mononuclear leukocyte DNA damage in patients with BPH.

PATIENTS AND METHODS

Twenty-six male patients with BPH and 24 healthy male subjects were included in this study. Blood samples were collected from antecubital vein after an overnight fasting period, and the plasma was separated. Plasma prolidase activity, total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) were determined. The peripheral lymphocyte oxidative DNA damage was determined using an alkaline single cell gel electrophoresis assay (comet assay).

RESULTS

The plasma prolidase activity, TOS levels, OSI values, and peripheral mononuclear leukocyte DNA damage were significantly higher (P < 0.001), while the TAC levels were significantly lower (P < 0.001) in patients with BPH than controls. In BPH patients, the prolidase activity was significantly associated with TAC levels (r = -0.366, P < 0.05), TOS levels (r = 0.573, P < 0.001), and OSI (r = 0.618, P < 0.001) and peripheral mononuclear leukocyte DNA damage (r = 0.461, P < 0.001).

CONCLUSIONS

Our results showed that BPH might be associated with an increased oxidative stress, and also an increased plasma prolidase activity. Increased prolidase activity might play an important role in the etiopathogenesis and/or progression of BPH.

Should modest elevations in prostate-specific antigen, International Prostate Symptom Score, or their rates of increase over time be used as surrogate measures of incident benign prostatic hyperplasia?

Although surrogate measures of benign prostatic hyperplasia (BPH) are often used in epidemiologic studies, their performance characteristics are unknown. Using data from the Prostate Cancer Prevention Trial (n = 5,986), we evaluated prostate-specific antigen (PSA), International Prostate Symptom Score (IPSS), and their rates of change as predictors of incident BPH. BPH (n = 842 cases) was defined as medical or surgical treatment or at least 2 IPSS of 15 or higher. Proportional hazards models were used to measure the associations of baseline PSA, IPSS, and their velocities over 2 years with BPH risk, and time-dependent receiver-operating characteristic curves were used to measure their discriminatory performance. Unit increases in PSA, IPSS, and IPSS velocity were associated with 34%, 35%, and 29% (all P < 0.001) increases in BPH risk, respectively. The areas under the receiver-operating characteristic curves were significantly greater than 0.5 for PSA (0.58, 95% confidence interval (CI): 0.56, 0.60), IPSS (0.77, 95% CI: 0.75, 0.78), and IPSS velocity (0.63, 95% CI: 0.61, 0.65); however there were no cut points at which sensitivity and specificity were both above 75%. We concluded that moderate elevations in PSA, IPSS, or their rates of change should not be used as surrogate measures of incident BPH.

Association of symptomatic benign prostatic hyperplasia and prostate cancer: results from the prostate cancer prevention trial

This study examined the association between symptomatic benign prostatic hyperplasia (BPH) and prostate cancer risk in 5,068 placebo-arm participants enrolled in the Prostate Cancer Prevention Trial (1993-2003). These data include 1,225 men whose cancer was detected during the 7-year trial--556 detected for cause (following abnormal prostate-specific antigen or digital rectal examination) and 669 detected not for cause (without indication), as well as 3,843 men who had biopsy-proven absence of prostate cancer at the trial end. Symptomatic BPH was assessed hierarchically as self-report of surgical or medical treatment, moderately severe symptoms (International Prostate Symptom Score >14), or physician diagnosis, and analyses were completed by BPH status at baseline (prevalent) or BPH prior to cancer diagnosis or study end (prevalent plus incident). Controlled for age, race, and body mass index, neither prevalent (risk ratio = 1.03, 95% confidence interval: 0.92, 1.14) nor prevalent plus incident (risk ratio = 0.96, 95% confidence interval: 0.87, 1.06) symptomatic BPH was associated with prostate cancer risk. This lack of association was consistent across subgroups defined by type of BPH-defining event (treatment, symptoms, or physician diagnosis), prompt for prostate cancer diagnosis, and prostate cancer grade. This study provides the strongest evidence to date that BPH does not increase the risk of prostate cancer.

Detection of TMPRSS2-ETS fusions by a multiprobe fluorescence in situ hybridization assay for the early diagnosis of prostate cancer: a pilot study

Fusion of the prostate-specific and androgen-regulated transmembrane-serine protease gene (TMPRSS2) with the erythroblast transformation-specific (ETS) family members is the most common genetic alteration in prostate cancer. However, the biological and clinical role of TMPRSS2-ETS fusions in prostate cancer, especially in problematic prostate needle core biopsies, has not been rigorously evaluated. We randomly collected 85 specimens including 50 archival prostate cancer tissue blocks, 15 normal prostate specimens, and 20 benign prostatic hyperplasia specimens for TMPRSS2-ETS fusion analyses. Moreover, the fusion status in an additional 20 patients with initial negative biopsies who progressed to biopsy-positive prostate cancer at subsequent follow-ups was also characterized. Fluorescently labeled probes specific for ERG-related rearrangements involving the TMPRSS2-ERG fusion as well as TMPRSS2-ETV1 and TMPRSS2-ETV4 were used to assess samples for gene rearrangements indicative of malignancy under a design of sequential trial. Rearrangements involving TMPRSS2-ETS fusions were detected in 90.0% of the 50 postoperative prostate cancer samples. The positive rate for the rearrangements in the initial prostate cancer-negative biopsies of 20 patients who eventually progressed to prostate cancer was 60.0% (12/20). Our preliminary study demonstrates that the clinical utility of TMPRSS2-ETS fusion detection as a biomarker and ancillary diagnostic tool for the early diagnosis of prostate cancer is promising, given this approach shows significant high sensitivity and specificity in detection.

Biomarkers of systemic inflammation and risk of incident, symptomatic benign prostatic hyperplasia: results from the prostate cancer prevention trial

The authors conducted a nested case-control study of serum inflammatory markers and risk of symptomatic benign prostatic hyperplasia (BPH), using data from the placebo arm of the Prostate Cancer Prevention Trial (1993-2003). Incident BPH (n = 676) was defined as treatment, report of 2 International Prostate Symptom Score (IPSS) values >14, or 2 increases of > or = 5 from baseline values with at least one value > or = 12. Controls (n = 683) were men who reported no BPH treatment or IPSS values >7 over the 7-year trial. Baseline serum was analyzed for C-reactive protein, tumor necrosis factor alpha (monomer), soluble tumor necrosis factor receptors I and II (sTNF-RI and sTNF-RII), interleukin 6, and interferon gamma. Controlled for age and race, a high C-reactive protein concentration was associated with increased BPH risk (for quartile 4 vs. quartile 1, odds ratio (OR) = 1.40, 95% confidence interval (CI): 1.04, 1.88); this was attenuated after control for body mass index (OR = 1.30, 95% CI: 0.95, 1.75). Low sTNF-RII and high interleukin 6 concentrations were associated with increased BPH risk (for quartile 4 vs. quartile 1, sTNF-RII: OR = 0.61, 95% CI: 0.46, 0.82; interleukin 6: OR = 1.79, 95% CI: 1.32, 2.42); these associations were only in men aged <65 years. Results suggest that systemic inflammation or lower levels of soluble receptors that bind inflammatory cytokines increase BPH risk.

Review of exercise and the risk of benign prostatic hyperplasia

It has been long appreciated that a healthy lifestyle plays a critical role in cardiovascular health. It is now apparent that the same is true in the development of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Since 1995, 14 studies have been identified that investigate the clinical relationship between exercise and BPH/LUTS. No randomized controlled trials have been performed, but useful prospective cohort data originating from recent publications on the medical treatment of BPH and prevention of prostate cancer are available. Most of the literature supports a clinically significant, independent, and strong inverse relationship between exercise and the development of BPH/LUTS. Several mechanisms for this relationship have been proposed, including decreased sympathetic tone, avoidance of metabolic syndrome, and reduced oxidative damage to the prostate.

Hsp-27 expression at diagnosis predicts poor clinical outcome in prostate cancer independent of ETS-gene rearrangement

BACKGROUND

This study was performed to test the hypothesis that expression of small heat shock protein Hsp-27 is, at diagnosis, a reliable predictive biomarker of clinically aggressive prostate cancer.

METHODS

A panel of tissue microarrays constructed from a well-characterised cohort of 553 men with conservatively managed prostate cancer was stained immunohistochemically to detect Hsp-27 protein. Hsp-27 expression was compared with a series of pathological and clinical parameters, including outcome.

RESULTS

Hsp-27 staining was indicative of higher Gleason score (P<0.001). In tissue cores having a Gleason score >7, the presence of Hsp-27 retained its power to independently predict poor clinical outcome (P<0.002). Higher levels of Hsp-27 staining were almost entirely restricted to cancers lacking ERG rearrangements (chi2 trend=31.4, P<0.001), although this distribution did not have prognostic significance.

INTERPRETATION

This study has confirmed that, in prostate cancers managed conservatively over a period of more than 15 years, expression of Hsp-27 is an accurate and independent predictive biomarker of aggressive disease with poor clinical outcome (P<0.001). These findings suggest that apoptotic and cell-migration pathways modulated by Hsp-27 may contain targets susceptible to the development of biologically appropriate chemotherapeutic agents that are likely to prove effective in treating aggressive prostate cancers.

Differential response to zinc-induced apoptosis in benign prostate hyperplasia and prostate cancer cells

Zinc concentrations in the prostate are uniquely high but are dramatically decreased with prostate cancer. Studies have suggested that increasing zinc in the prostate may be a potential therapeutic strategy. The goal of this study was to evaluate the antiproliferative effects of zinc in prostate cancer cells (PC-3) and noncancerous benign prostate hyperplasia (BPH) cells (BPH-1) and to define possible mechanisms. PC-3 and BPH-1 cells were treated with zinc (0-250 microM) for 24 and 48 h, and cell growth and viability were examined. Apoptosis was assessed by phosphatidylserine externalization, caspase activation and protein expression of B-cell CLL/lymphoma 2 (Bcl-2)-associated X protein (BAX):Bcl-2. BPH-1 cells were more sensitive to the antiproliferative effects of zinc compared to PC-3. The response to zinc in PC-3 and BPH-1 cells differed as evidenced by opposing effects on Bcl-2:BAX expression. Additionally, different effects on the nuclear expression and activity of the p65 subunit of nuclear factor kappa B were observed in response to zinc between the two cell types. The differential response to zinc in PC-3 and BPH-1 cells suggests that zinc may serve an important role in regulating cell growth and apoptosis in prostate cancer and hyperplasia cells.

Serum steroid and sex hormone-binding globulin concentrations and the risk of incident benign prostatic hyperplasia: results from the prostate cancer prevention trial

The authors conducted a nested case-control study of serum steroid concentrations and risk of benign prostatic hyperplasia (BPH), using data from the placebo arm of the Prostate Cancer Prevention Trial (1993-2003). Incident BPH over 7 years (n = 708) was defined as receipt of treatment, a report of 2 International Prostate Symptom Score (IPSS) values greater than 14, or 2 increases of 5 or more from baseline IPSS values with at least 1 value greater than or equal to 12. Controls (n = 709) were selected from men who reported no BPH treatment or any IPSS greater than 7. Baseline serum was analyzed for testosterone, estradiol, estrone, 5alpha-androstane-3alpha, 17beta-diol-glucuronide, and sex hormone-binding globulin. Covariate-adjusted odds ratios contrasting the highest quartiles with the lowest quartiles of testosterone, estradiol, and testosterone:17beta-diol-glucuronide ratio were 0.64 (95% confidence interval (CI): 0.43, 0.95; P(trend) = 0.04), 0.72 (95% CI: 0.53, 0.98; P(trend) = 0.09), and 0.64 (95% CI: 0.46, 0.89; P(trend) = 0.004), respectively. Findings did not differ by age, body mass index, time to BPH endpoint, or type of BPH endpoint. High testosterone levels, estradiol levels, and testosterone:17beta-diol-glucuronide ratio are associated with reduced BPH risk, which may reflect decreased activity of 5-alpha-reductase. Genetic or environmental factors that affect the activity of 5-alpha-reductase may be important in the development of symptomatic BPH.

Contrast-enhanced transrectal ultrasound for assessing vascularization of hypoechoic BPH nodules in the transition and peripheral zones: comparison with pathological examination

The purpose of this study was to investigate the vascularization of zonal location of hypoechoic benign prostatic hyperplasia (BPH) nodules and to evaluate the clinical value of contrast-enhanced transrectal ultrasound (CETRUS) for assessing vascularity of hypoechoic BPH nodules. Sixty-two patients with hypoechoic biopsy-proven BPH nodules in transition zone (TZ) (32 patients) or peripheral zone (PZ) (30 patients) of the prostate gland underwent CETRUS examination between January 2006 and September 2006. The enhancement characteristics of hypoechoic BPH nodules were observed and time to enhancement (AT), time to peak intensity (TTP) and peak intensity (PI) were measured with ACQ time-intensity curve analysis software. In addition, microvessel density (MVD) and vascular endothelial growth factor (VEGF) immunoreactivity were determined in the biopsy specimens. Microvessels were identified by immunohistochemical staining of endothelial cells for CD34. Findings were compared between hypoechoic BPH nodules located in PZ and TZ. The most common enhancement characteristic of hypoechoic BPH nodules in PZ was nonenhanced area inside (21/30), while most of hypoechoic BPH nodules in TZ appeared homogeneous enhancement (28/32). The average AT and TTP were significantly longer, the average PI was significantly lower in hypoechoic BPH nodules located in PZ than TZ (p < 0.01). The VEGF expression and MVD were significantly higher in hypoechoic BPH nodules located in TZ than PZ (p < 0.01). PI was found to be an important parameter strongly correlated with degree of vascularity of hypoechoic BPH nodules. Hypoechoic BPH nodules located in PZ and TZ showed significant difference in vascularization, which indirectly verified our finding that BPH nodule could occur in the peripheral zone. CETRUS could afford information on the vascularity of hypoechoic BPH nodules in a noninvasive manner and this could be used to improve selection of nodules for biopsy.

Insulin-like growth factor-I, insulin-like growth factor binding protein-3 and risk of benign prostate hyperplasia in the prostate cancer prevention trial

BACKGROUND

We investigated whether peptides involved in cellular proliferation and apoptosis, [insulin-like growth factor I (IGFI) and its major binding protein (insulin-like growth factor binding protein 3)], predicted risk of benign prostate hyperplasia (BPH).

METHODS

We conducted a nested-case-control study in the placebo arm of the prostate cancer prevention trial (PCPT). Cases (n = 727) were men with surgical or medical treatment for BPH; two or more IPSS scores >14; or two scores of at least five points over baseline one of which was >or=12. Controls (n = 727) were frequency matched by age to cases, reported no BPH treatment, and no IPSS score >8. Cases and controls remained on the PCPT placebo and were followed closely until their 7-year PCPT anniversary. Baseline serum was analyzed for IGFI and IGFBP3. Unconditional logistic regression and polytomous regression estimated the multivariate-adjusted odds ratio (OR) for BPH risk.

RESULTS

IGFBP3 was inversely and the IGFI:IGFBP3 ratio was positively associated with BPH risk, but findings were statistically significant only for men with severe symptoms (OR = 0.60, 95% CI = 0.40-0.90 for the fifth vs. first quintile of IGFBP3, P-trend = 0.01). Associations did not differ by age (<65 or >or=65 years), and there was a suggestion that the IGFI:IGFBP3 - BPH risk association may be stronger among overweight men.

CONCLUSIONS

A high IGFI:IGFBP3 ratio was associated with increased BPH risk, and high serum IGFBP3 was associated with decreased BPH risk among men with severe symptoms. These results confirm findings from other recent studies.

Identification of claudin-4 as a marker highly overexpressed in both primary and metastatic prostate cancer

In the quest for markers of expression and progression for prostate cancer (PCa), the majority of studies have focussed on molecular data exclusively from primary tumours. Although expression in metastases is inferred, a lack of correlation with secondary tumours potentially limits their applicability diagnostically and therapeutically. Molecular targets were identified by examining expression profiles of prostate cell lines using cDNA microarrays. Those genes identified were verified on PCa cell lines and tumour samples from both primary and secondary tumours using real-time RT–PCR, western blotting and immunohistochemistry. Claudin-4, coding for an integral membrane cell-junction protein, was the most significantly (P<0.00001) upregulated marker in both primary and metastatic tumour specimens compared with benign prostatic hyperplasia at both RNA and protein levels. In primary tumours, claudin-4 was more highly expressed in lower grade (Gleason 6) lesions than in higher grade (Gleason ⩾7) cancers. Expression was prominent throughout metastases from a variety of secondary sites in fresh-frozen and formalin-fixed specimens from both androgen-intact and androgen-suppressed patients. As a result of its prominent expression in both primary and secondary PCas, together with its established role as a receptor for Clostridium perfringens enterotoxin, claudin-4 may be useful as a potential marker and therapeutic target for PCa metastases.

Heterogeneity and clinical significance of ETV1 translocations in human prostate cancer

A fluorescence in situ hybridisation (FISH) assay has been used to screen for ETV1 gene rearrangements in a cohort of 429 prostate cancers from patients who had been diagnosed by trans-urethral resection of the prostate. The presence of ETV1 gene alterations (found in 23 cases, 5.4%) was correlated with higher Gleason Score (P=0.001), PSA level at diagnosis (P=<0.0001) and clinical stage (P=0.017) but was not linked to poorer survival. We found that the six previously characterised translocation partners of ETV1 only accounted for 34% of ETV1 re-arrangements (eight out of 23) in this series, with fusion to the androgen-repressed gene C15orf21 representing the commonest event (four out of 23). In 5'-RACE experiments on RNA extracted from formalin-fixed tissue we identified the androgen-upregulated gene ACSL3 as a new 5'-translocation partner of ETV1. These studies report a novel fusion partner for ETV1 and highlight the considerable heterogeneity of ETV1 gene rearrangements in human prostate cancer.

Does benign prostatic hyperplasia originate from the peripheral zone of the prostate? A preliminary study

OBJECTIVE

To compare the histological characteristics, cell proliferation, apoptosis and biological features in benign prostatic hyperplasia (BPH) in the peripheral (PZ) and transition zone (TZ) of the prostate.

PATIENTS AND METHODS

Tissue from BPH in TZ and PZ was obtained from 68 patients undergoing transrectal ultrasonography-guided biopsy and used for both morphometric analysis and immunohistochemical studies. The epithelial, stromal and luminal composition of the tissue was determined using a computer-assisted method for quantitative morphometric analysis. Apoptosis was detected as the apoptotic index (AI) using the TdT dUTP nick-end labelling assay. Cell proliferation was determined as the proliferation index (PI) using Ki-67 immunostaining. The expression of epidermal growth factor receptor (EGFR), transforming growth factor beta1 (TGFbeta1), androgen receptor (AR) and bcl-2 were assessed immunohistochemically.

RESULTS

There was no difference in the stroma/epithelium ratio between PZ and TZ hyperplastic nodules (P > 0.05). The mean AI in epithelium was almost identical to the corresponding PI. In stroma, no apoptotic cells were detectable. There was a significantly higher PI and AI in the glandular epithelial cells in PZ hyperplastic than in TZ hyperplastic nodules, but no difference in PI of the stromal cells between PZ and TZ hyperplastic nodules. There was significantly higher expression of TGFbeta1 and lower expression of EGFR and bcl-2 in PZ than TZ hyperplastic nodules (P < 0.05). There was no difference in AR expression between PZ and TZ hyperplastic nodules (P > 0.05).

CONCLUSIONS

These results indicate that some hyperplastic nodules in PZ might originate from the PZ, and the formation of these nodules might be modulated in a different way from that in the TZ.

Complex patterns of ETS gene alteration arise during cancer development in the human prostate

An ERG gene 'break-apart' fluorescence in situ hybridization (FISH) assay has been used to screen whole-mount prostatectomy specimens for rearrangements at the ERG locus. In cancers containing ERG alterations the observed pattern of changes was often complex. Different categories of ERG gene alteration were found either together in a single cancerous region or within separate foci of cancer in the same prostate slice. In some cases the juxtaposition of particular patterns of ERG alterations suggested possible mechanisms of tumour progression. Prostates harbouring ERG alterations commonly also contained cancer that lacked rearrangements of the ERG gene. A single trans-urethral resection of the prostate specimen examined harboured both ERG and ETV1 gene rearrangements demonstrating that the observed complexity may, at least in part, be explained by multiple ETS gene alterations arising independently in a single prostate. In a search for possible precursor lesions clonal ERG rearrangements were found both in high grade prostatic intraepithelial neoplasia (PIN) and in atypical in situ epithelial lesions consistent with the diagnosis of low grade PIN. Our observations support the view that ERG gene alterations represent an initiating event that promotes clonal expansion initially to form regions of epithelial atypia. The complex patterns of ERG alteration found in prostatectomy specimens have important implications for the design of experiments investigating the clinical significance and mechanism of development of individual prostate cancers.

Duplication of the fusion of TMPRSS2 to ERG sequences identifies fatal human prostate cancer

New predictive markers for managing prostate cancer are urgently required because of the highly variable natural history of this disease. At the time of diagnosis, Gleason score provides the gold standard for assessing the aggressiveness of prostate cancer. However, the recent discovery of TMPRSS2 fusions to the ERG gene in prostate cancer raises the possibility of using alterations at the ERG locus as additional mechanism-based prognostic indicators. Fluorescence in situ hybridization (FISH) assays were used to assess ERG gene status in a cohort of 445 prostate cancers from patients who had been conservatively managed. The FISH assays detected separation of 5' (labelled green) and 3' (labelled red) ERG sequences, which is a consequence of the TMPRSS2-ERG fusion, and additionally identify interstitial deletion of genomic sequences between the tandemly located TMPRSS2 and ERG gene sequences on chromosome 21. Cancers lacking ERG alterations exhibited favourable cause-specific survival (90% survival at 8 years). We identify a novel category of prostate cancers, characterized by duplication of the fusion of TMPRSS2 to ERG sequences together with interstitial deletion of sequences 5' to ERG (called '2+Edel'), which by comparison exhibited extremely poor cause-specific survival (hazard ratio=6.10, 95% confidence ratio=3.33-11.15, P<0.001, 25% survival at 8 years). In multivariate analysis, '2+Edel' provided significant prognostic information (P=0.003) in addition to that provided by Gleason score and prostate-specific antigen level at diagnosis. Other individual categories of ERG alteration were associated with intermediate or good prognosis. We conclude that determination of ERG gene status, including duplication of the fusion of TMPRSS2 to ERG sequences in 2+Edel, allows stratification of prostate cancer into distinct survival categories.

Establishment of an organotypic in vitro culture system and its relevance to the characterization of human prostate epithelial cancer cells and their stromal interactions

Human prostatic adenocarcinoma fragments (1-6mm) were cultured on collagen sponges in medium supplemented or not supplemented with 4,5alpha-dihydrotesterone (DHT) until 3 weeks, maintaining the three-dimensional (3D) epithelial and stromal organization present in the tumor in vivo. With time, in the presence of DHT, locally progressive cribriform nests of neoplastic cells with proliferative rates higher than those inside the fragment developed on the surface, while the stroma became more dissociated, and fibrosis replaced the muscular component. The 3D-culture provides a promising approach for studying the development and phenotype of prostate epithelial tumor progenitor cells and their stromal interactions.

The effect of oxytocin on cell proliferation in the human prostate is modulated by gonadal steroids: implications for benign prostatic hyperplasia and carcinoma of the prostate

BACKGROUND

Oxytocin (OT) is implicated in regulating prostate growth. OT concentrations are increased in benign, and decreased in malignant prostate disease. This study investigated whether the altered concentrations of OT present in prostate disease affect the proliferation of malignant and non-malignant human prostate cells.

METHODS

The effects of varying concentrations of OT and gonadal steroids on cell proliferation of non-malignant prostatic epithelial (PrEC) and stromal (PrSC) cells and androgen dependent (LNCaP) and independent (PC-3) malignant cell lines were assessed.

RESULTS

OT (>0.5 nmol . L(-1)) had no effect on PrEC proliferation when cells were cultured alone. When co-cultured with PrSC and gonadal steroids, OT inhibited epithelial cell proliferation. OT inhibited PrSC proliferation, when cells were cultured alone. When PrSC were co-cultured in the presence of estrogen physiological concentrations of OT were inhibitory. No effect on cell proliferation was observed with higher concentrations of OT. OT did not affect the proliferation of malignant cell lines in the absence of androgens but, in the presence of testosterone, low concentrations of OT (<1 nmol . L(-1)) stimulated proliferation of PC-3 cells. Disruption of caveolae in the plasma membrane removed the inhibitory effect of OT on PrSC proliferation but did not affect the stimulatory effect of OT on PC-3 cells cultured in the presence of androgens.

CONCLUSIONS

Changes in prostatic concentrations of OT that occur with aging and malignant disease may act to facilitate cell proliferation. The localization of the OT receptor within the plasma membrane modulates OT's proliferative response in the prostate.

Oxytocin and the human prostate in health and disease

Oxytocin is a peptide hormone produced by the neurohypophysis. The discovery that the peptide is produced locally within the male and female reproductive tracts has raised the possibility that oxytocin may have paracrine and autocrine actions outside of the nervous system. Oxytocin and its receptor have been identified in the human prostate. The prostate is an androgen-dependent organ whose function is to secrete components of the seminal fluid. Oxytocin has been shown to modulate contractility of prostate tissue and also to regulate local concentrations of the biologically active androgens. Oxytocin has also been shown to regulate cell growth. Prostate disease is common and results from abnormal growth of the gland. Oxytocin concentrations are altered in both benign and malignant prostate diseases and in vitro studies suggest that the peptide may be involved in the pathophysiology of these diseases.

Apoptosis profiles in benign prostatic hyperplasia: close associations of cell kinetics with percent area density of histologic composition

OBJECTIVES

To investigate the possible correlations of apoptosis and apoptosis-associated factors, including the apoptotic index (AI), proliferation index (PI), and expression of Bcl-2 and caspase 3, with the percent area density of epithelium and stroma in benign prostatic hyperplasia (BPH).

METHODS

A total of 60 patients with histologically determined BPH were investigated. The percent area density of epithelium and stroma was determined using a computerized image analysis system after Masson's trichrome staining. Apoptosis was detected using the AI through the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling assay. Cell proliferation was determined using the PI through Ki-67 immunostaining. The expression of Bcl-2 and caspase 3 was immunohistochemically examined. Double-label immunofluorescent staining was performed to assess co-localization of Bcl-2 and caspase 3.

RESULTS

The stroma/epithelium ratio ranged from 4.6 to 6.3 (average 5.2) in BPH. A greater stromal PI was closely related to the percent area density of stroma (P <0.01), and a greater epithelial AI was reversely related to the percent area density of the epithelium (P <0.05). Bcl-2 and caspase 3 expression was detected in 50 (80%) and 48 (75%) of 60 BPH samples, respectively. The expression of Bcl-2 and caspase 3 was not related to PI, AI, or the percent area density of the BPH components (P >0.05). Immunofluorescence analysis revealed co-localization of Bcl-2 and caspase 3 in the serial sections of BPH specimens that already showed either Bcl-2 or caspase 3 expression.

CONCLUSIONS

The development of BPH may be associated with both stromal growth due to active stromal cell proliferation and epithelial growth due to reduced glandular apoptosis.

Saw palmetto is an indirectly acting sympathomimetic in the rat-isolated prostate gland

BACKGROUND

To investigate whether saw palmetto that inhibits alpha1-adrenoceptor binding in vitro affects contractility of the rat prostate gland.

METHODS

The effects of a commercially available saw palmetto extract were examined on the contractility of rat-isolated prostate glands. The extract was tested in the presence and absence of phentolamine, prazosin, yohimbine, propranolol, hexamethonium, cocaine, desipramine, nifedipine, guanethidine, atropine, and alpha,beta-methylene ATP to evaluate the mechanism of action. Isolated preparations of rat vas deferens and bladder were used for comparison.

RESULTS

Unexpectedly, saw palmetto extract caused contractions of the rat prostate gland that could be attenuated by prazosin, phentolamine, nifedipine, guanethidine, cocaine, and desipramine but not by any of the other pharmacological tools. Similar contractile effects were observed in rat-isolated vas deferens preparations but not in rat-isolated bladder preparations.

CONCLUSIONS

In the rat prostate gland, saw palmetto extract causes indirect alpha1-adrenoceptor-mediated contractions via the release of noradrenaline from sympathetic neurons.

Monotherapy versus combination drug therapy for the treatment of benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH) is a medical condition occurring in older men (ie, those aged >60 years) resulting from enlargement of the prostate gland. Consequently, affected men may experience bother-some urinary tract symptoms and diminished quality of life. The risk of lower urinary tract symptoms and complications such as acute urinary retention (AUR) may increase if BPH is untreated. Currently, 2 classes of drugs-alpha-adrenergic blockers (alpha-blockers) and 5alpha-reductase inhibitors-are indicated for the treatment of BPH. Although the 2 classes are commonly used in combination, the evidence has frequently not been supportive of this practice. Results from the Medical Therapy of Prostatic Symptoms (MTOPS) trial, the largest and longest clinical trial on this topic to date, revisited the role of combination therapy in the treatment of BPH.

OBJECTIVE

This review presents published trials evaluating alpha-blockers or 5alpha-reductase inhibitors used alone or in combination for the treatment of BPH.

METHODS

A MEDLINE search was conducted (December 1974 to November 2004) using the MeSH term prostatic hyperplasia limited to the subheading of drug therapy. These results were cross-referenced with the MeSH term combination drug therapy. An additional search was conducted using the MeSH terms finasteride and adrenergic alpha-antagonists limited to adverse effects and therapeutic uses. These results were cross-referenced with prostatic hyperplasia and combination drug therapy. Review articles and meta-analyses were also used.

RESULTS

The Veterans Affairs Cooperative Studies Benign Prostatic Hyperplasia Study Group and the Prospective European Doxazosin and Combination Therapy studies were well-designed trials that failed to support the theory that combination therapy is preferred over alpha-blockers alone. Finasteride was also shown to be no better than placebo for the outcomes of symptom score and peak urinary flow rates. Other trials suggested that combination therapy (which included finasteride) was more effective at reducing symptom scores in men with enlarged prostates at 1 year and that alpha-blockers may be successfully discontinued once patients are stabilized on finasteride. Although it was a prespecified secondary end point, the incidence of surgery or AUR was reduced by 51% using finasteride over placebo. The additive benefit finasteride provides in reducing symptoms, risk of AUR, and invasive surgery was observed within the first year of treatment and correlated with larger prostate sizes (mean [SD], approximately 55 [26] mL). The MTOPS trial further demonstrated a relative risk reduction of 66% in clinical progression rates for the combination-therapy group versus 39% for the doxazosin group compared with placebo (P < 0.001); the doxazosin group was not statistically different from the finasteride monotherapy group. Improvements in symptom scores were greater in the combination-therapy group versus the doxazosin (P = 0.006) and finasteride monotherapy (P < 0.001) groups.

CONCLUSION

Based on the literature, combination therapy has been proven to relieve symptoms and delay progression of BPH in men with moderate to severe symptoms and moderately enlarged prostate glands.

Dual activation of pathways regulated by steroid receptors and peptide growth factors in primary prostate cancer revealed by Factor Analysis of microarray data

Background

We use an approach based on Factor Analysis to analyze datasets generated for transcriptional profiling. The method groups samples into biologically relevant categories, and enables the identification of genes and pathways most significantly associated to each phenotypic group, while allowing for the participation of a given gene in more than one cluster. Genes assigned to each cluster are used for the detection of pathways predominantly activated in that cluster by finding statistically significant associated GO terms. We tested the approach with a published dataset of microarray experiments in yeast. Upon validation with the yeast dataset, we applied the technique to a prostate cancer dataset.

Results

Two major pathways are shown to be activated in organ-confined, non-metastatic prostate cancer: those regulated by the androgen receptor and by receptor tyrosine kinases. A number of gene markers (HER3, IQGAP2 and POR1) highlighted by the software and related to the later pathway have been validated experimentally a posteriori on independent samples.

Conclusion

Using a new microarray analysis tool followed by a posteriori experimental validation of the results, we have confirmed several putative markers of malignancy associated with peptide growth factor signalling in prostate cancer and revealed others, most notably ERRB3 (HER3). Our study suggest that, in primary prostate cancer, HER3, together or not with HER4, rather than in receptor complexes involving HER2, could play an important role in the biology of these tumors. These results provide new evidence for the role of receptor tyrosine kinases in the establishment and progression of prostate cancer.

Trypsin stimulates the phosphorylation of p42,44 mitogen-activated protein kinases via the proteinase-activated receptor-2 and protein kinase C epsilon in human cultured prostate stromal cells

BACKGROUND

The pathogenesis of benign prostatic hyperplasia (BPH) is not well understood. It involves the proliferation of prostate stromal cells. The proteinase-activated receptor subtype 2 (PAR-2) receptor is expressed by human prostate tissue and can be stimulated by serine proteases. Prostate epithelial cells secrete serine proteases such as trypsin, prostate specific antigen (PSA), and human glandular kallikrein (hK2). The p42,44 mitogen activated protein kinase (MAP kinase) pathway regulates cell proliferation. Trypsin can stimulate this pathway via the PAR-2 receptor and protein kinase C (PKC) in other tissues. Serine proteases secreted by prostate epithelial cells may interact with PAR-2 receptors expressed by prostate stromal cells causing them to proliferate. The aim of the present study was to establish whether functional PAR-2 receptors are expressed by human prostate stromal cells (HPSCs) and to determine whether PAR-2 stimulation can activate p42,44 MAP kinase via a pathway involving PKC.

METHODS

HPSCs were cultured from patients undergoing trans urethral resection of the prostate (TURP). HPSCs were stimulated with PAR agonists. Immunoblotting of HPSC lysate with anti-p42,44 MAP kinase and -PKC isoforms. Data were analyzed with densitometry.

RESULTS

Trypsin and the PAR-2 synthetic peptide SLIGKV caused significant increases in MAP kinase phosphorylation and calcium mobilization in HPSCs. The MAP kinase response was attenuated by pertussis toxin (PTX), phorbol 12,13 dibutyrate, Go6983, and Ro 318220. The PKC isoforms alpha, delta, epsilon, and zeta were detected in HPSCs. Trypsin caused the translocation of PKC(epsilon) from the cytosol to the membrane in HPSCs and was able to stimulate cellular proliferation.

CONCLUSIONS

The PAR-2 selective serine protease trypsin activates p42,44 MAP kinase phosphorylation via PKC(epsilon). This may be an important mechanism of BPH pathophysiology.

Transcription factor E2F3 overexpressed in prostate cancer independently predicts clinical outcome

E2F transcription factors, including E2F3, directly modulate expression of EZH2. Recently, overexpression of the EZH2 gene has been implicated in the development of human prostate cancer. In tissue microrarray studies we now show that expression of high levels of nuclear E2F3 occurs in a high proportion (98/147, 67%) of human prostate cancers, but is a rare event in non-neoplastic prostatic epithelium suggesting a role for E2F3 overexpression in prostate carcinogenesis. Patients with prostate cancer exhibiting immunohistochemically detectable nuclear E2F3 expression have poorer overall survival (P=0.0022) and cause-specific survival (P=0.0047) than patients without detectable E2F3 expression. When patients are stratified according to the maximum percentage of E2F3-positive nuclei identified within their prostate cancers (up to 20, 21-40%, etc.), there is an increasingly significant association between E2F3 staining and risk of death both for overall survival (P=0.0014) and for cause-specific survival (P=0.0004). Multivariate analyses select E2F3 expression as an independent factor predicting overall survival (unstratified P=0.0103, stratified P=0.0086) and cause-specific survival (unstratified P=0.0288, stratified P=0.0072). When these results are considered together with published data on EZH2 and on the E2F3 control protein pRB, we conclude that the pRB-E2F3-EZH2 control axis may have a critical role in modulating aggressiveness of individual human prostate cancer.

Biologic feature of prostatic hyperplasia developed in spontaneously hypertensive rats

OBJECTIVES

To investigate alterations in cell kinetic and cellular composition in prostatic hyperplasia developed in spontaneously hypertensive (SH) rats from 15 to 54 weeks of age.

METHODS

Male SH rats (n = 20) and their normotensive counterparts, Wistar-Kyoto rats (n = 20), were studied. At 15, 29, 40, and 54 weeks of age, the ventral prostate was obtained to evaluate (a) cell proliferation by the proliferation index using proliferating cell nuclear antigen immunostaining and (b) apoptosis by the apoptotic index using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling assay. The percentage of area density of smooth muscle and fibroblastic tissues was determined with a computerized image analysis system after alpha-actin and vimentin immunostaining, respectively.

RESULTS

Compared with the data in the Wistar-Kyoto rats during the observation period, a significantly increased proliferation index in both epithelium and stroma (P <0.01) and a slightly increased apoptotic index in the epithelium without apoptotic cells in the stroma, with an imbalance in favor of cell proliferation, were noted in the prostatic hyperplasia of the SH rats. The value of the proliferation index was greatly increased in both the epithelium and the stroma of the SH rats between 15 and 29 weeks (P <0.05) but continued relatively steady from 29 to 54 weeks. A significantly increased percentage of smooth muscle area (P <0.01) and a much greater percentage of area density of smooth muscle than that of fibroblastic tissues (P <0.01) were observed in the prostatic hyperplasia of the SH rats.

CONCLUSIONS

The prostatic hyperplasia of SH rats may develop from both epithelial and stromal growth and could ultimately be promoted by an imbalance in favor of proliferative activity.

Ion-channel currents of smooth muscle cells isolated from the prostate of guinea-pig

OBJECTIVE

To characterize the voltage-activated ion-channel currents in guinea-pig prostate smooth muscle cells (GPSMCs).

MATERIALS AND METHODS

GPSMCs were isolated using collagenase, and used in a whole-cell patch clamp study.

RESULTS

When GPSMCs were dialysed with a CsCl solution all the outward K+ currents were blocked and the step-like depolarization (holding voltage -70 mV) of the cell membrane evoked inward currents that were completely blocked by nifedipine (1 micromol/L). With KCl solution, step depolarizations showed outward K+ currents composed of fast, transient outward current (Ito) and outward currents that did not inactivate. Ito was resistant to a high concentration of tetraethylammonium (TEA, 5 mmol/L) but was blocked by 4-aminopyridine (5 mmol/L). The half-activation and half-inactivation voltages of Ito were 6 mV and -58 mV, respectively. With low Ca2+ buffer (0.1 mmol/L EGTA) in the solution, there were spontaneous transient outward currents (STOCs) at depolarized membrane voltages (0 mV). STOCs were blocked by TEA (1 mmol/L) or iberiotoxin (10 nmol/L) but were insensitive to apamin (100 nmol/L).

CONCLUSION

This voltage-clamp study showed that GPSMCs have l-type Ca2+ channels and more than two types of K+ channels. The voltage- and time-dependent changes of these ion channels and their interactions might be important in forming action potentials and regulating contractility.

The role of dihydrotestosterone in benign prostatic hyperplasia

This article examines the role of the androgen dihydrotestosterone (DHT) in the healthy and diseased prostate and considers the implications of the data on DHT for therapeutic approaches to benign prostatic hyperplasia (BPH). Development and maintenance of the normal prostate, as well as development of BPH, depend on a functional androgen-signaling axis, components of which include: (1) testosterone synthesis in the testes and adrenal glands; (2) conversion of testosterone to DHT; (3) transport of DHT to target tissues; and (4) binding of DHT to the androgen receptor with consequent modulation of genes. DHT plays a beneficial role in the developing prostate but it can be detrimental in the adult prostate in that it causes pathologic prostate growth. The role of DHT in other adult tissues is uncertain. DHT has not been shown to perform beneficial functions unique from testosterone in the adult male, and it is believed that its fundamental effect is to amplify testosterone's weaker hormonal signal. Increased understanding of the cellular mechanisms by which the androgen-signaling axis functions has led to advances in treatment for prostate disease. In BPH, the 5alpha-reductase inhibitors--the only class of therapy to act at the pathophysiologic substrate of the disease--arrest the disease process, reduce prostate volume, improve symptoms, and reduce the risk of acute urinary retention and BPH-related surgery. The availability of dutasteride, the first dual (Type 1/Type 2) 5alpha-reductase inhibitor, offers the opportunity for rapid and consistent inhibition of DHT.