Mechanisms of inhibition of human benign prostatic hyperplasia in vitro by the luteinizing hormone-releasing hormone antagonist cetrorelix

Growth hormone-releasing hormone antagonists counteract hydrogen peroxide - induced paracellular hyperpermeability in endothelial cells

Growth Hormone-Releasing Hormone (GHRH) is a hypothalamic peptide which regulates the release of Growth Hormone from the anterior pituitary gland, and has been involved in inflammatory processes. On the other hand, GHRH antagonists (GHRHAnt) were developed to counteract those effects. Herein we demonstrate for the first time that GHRHAnt can suppress hydrogen peroxide (H2O2) - induced paracellular hyperpermeability in bovine pulmonary artery endothelial cells. Increased production of reactive oxygen species (ROS) and barrier dysfunction have been associated with the development of potentially lethal disorders, including sepsis and acute respiratory distress syndrome (ARDS). Our study supports the protective actions of GHRHAnt in the impaired endothelium, and suggests that those compounds represent an exciting therapeutic possibility towards lung inflammatory disease.

Growth Hormone-Releasing Hormone in Endothelial Inflammation

The discovery of hypothalamic hormones propelled exciting advances in pharmacotherapy and improved life quality worldwide. Growth hormone-releasing hormone (GHRH) is a crucial element in homeostasis maintenance, and regulates the release of growth hormone from the anterior pituitary gland. Accumulating evidence suggests that this neuropeptide can also promote malignancies, as well as inflammation. Our review is focused on the role of that 44 - amino acid peptide (GHRH) and its antagonists in inflammation and vascular function, summarizing recent findings in the corresponding field. Preclinical studies demonstrate the protective role of GHRH antagonists against endothelial barrier dysfunction, suggesting that the development of those peptides may lead to new therapies against pathologies related to vascular remodeling (eg, sepsis, acute respiratory distress syndrome). Targeted therapies for those diseases do not exist.

The highly interrelated GHRH, p53, and Hsp90 universe

p53 universe is composed of a complex regulatory network, destined to counteract multifarious challenges threatening cell survival. Imbalance in those responses may result in human disease associated with inevitable consequences. The present work delivers our view of the corresponding phenomena, by involving the endothelium defender in meticulously orchestrated events against inflammatory stimuli. Immersing into the great depths of p53 cosmos may lead to promising therapies against devastating disorders, including acute respiratory distress syndrome.

Emerging drugs to target lower urinary tract symptomatology (LUTS)/benign prostatic hyperplasia (BPH): focus on the prostate

OBJECTIVES

The benign prostatic syndrome, comprising lower urinary tract symptomatology secondary to benign prostatic hyperplasia/enlargement, represents a major health care issue in westernized countries. The pharmacological management involves alpha-adrenoceptor antagonists, intervention into the hormonal control of prostate growth using inhibitors of the enzyme 5-alpha-reductase, and stimulation of the nitric oxide/cyclic GMP pathway by tadalafil, an inhibitor of the phosphodiesterase type 5.

METHODS

This review summarizes the achievements which have been made in the development of drug candidates assumed to offer opportunities as beneficial treatment options in the management of the benign prostatic syndrome.

RESULTS

A review of the literature has revealed that the line of development is focusing on drugs interfering with peripheral neuromuscular/neuronal mechanisms (nitric oxide donor drugs, agonists/antagonists of endogenous peptides, botulinum toxin, NX-1207), the steroidal axis (cetrorelix) or the metabolic turn-over (lonidamine), as well as the combination of drugs already established in the treatment of lower urinary tract symptomatology/benign prostatic hyperplasia (phosphodiesterase 5 inhibitor plus alpha-adrenoceptor antagonist).

CONCLUSION

Many research efforts have provided the basis for the development of new therapeutic modalities for the management of lower urinary tract dysfunctions, some of which might be offered to the patients in the near future.

Comparison between selected hormone and protein levels in serum and prostate tissue homogenates in men with benign prostatic hyperplasia and metabolic disorders

Purpose

The purpose of the study was to assess the relationship between changes in the levels of selected hormones in serum and prostate tissue homogenate in regard to metabolic disorders in patients with diagnosed, surgically treated benign prostatic hyperplasia (BPH).

Patients and methods

The study involved a group of 154 men with a diagnosis of BPH with metabolic syndrome (MetS) and without MetS. The serum levels of the hormones – total testosterone, free testosterone, insulin, dehydroepiandrosterone sulfate, estradiol, luteinizing hormone, sex hormone binding globulin (SHBG), and insulin-like growth factor-1 (IGF-1) – were determined using the ELISA method. Prostate tissue sections obtained from the patients during transurethral resection of the prostate were frozen in liquid nitrogen. We determined the levels of the same hormones.

Results

There was a statistically significant difference between the groups in terms of serum SHBG levels, but not in the prostate tissue SHBG levels. A similar relationship was observed in regard to IGF-1, the serum levels of which were significantly higher in patients with MetS. MetS had an effect on the ratio of hormone levels in serum to their levels in the prostate tissue. Correlations between the levels of biochemical parameters and the levels of hormones in serum and the prostate tissue of BPH patients with and without MetS demonstrate that serum SHBG levels correlated weakly with waist size and triglyceride levels.

Conclusion

The occurrence of MetS in BPH patients was associated with changes in the levels of hormones and proteins. These changes, however, were not always equivalent to changes in the levels of these parameters in prostate tissue. It should also be mentioned that MetS in BPH patients had an influence on a quantitative balance between the levels of SHBG in serum and prostate tissue.

Epigallocatechin-3-gallate reduces the proliferation of benign prostatic hyperplasia cells via regulation of focal adhesions

AIMS

Benign prostatic hyperplasia (BPH) is the most common urological disease that is characterized by the excessive growth of prostatic epithelial and stromal cells. Pharmacological therapy for BPH has limited use due to the many side effects so there is a need for new agents including natural compounds such as epigallocatechin-3-gallate (EGCG). This study was undertaken to assess the role of EGCG, suppressing the formation of BPH by reducing inflammation and oxidative stress, in cytoskeleton organization and ECM interactions via focal adhesions.

MAIN METHODS

We performed MTT assay to investigate cell viability of BPH-1 cells, wound healing assay to examine cell migration, immunofluorescence assay for F-actin organization and paxillin distribution and finally immunoblotting to investigate focal adhesion protein levels in the presence and absence of EGCG.

KEY FINDINGS

We found that EGCG inhibits cell proliferation at the concentration of 89.12μM, 21.2μM and 2.39μM for 24, 48 and 72h, respectively as well as inhibitory effects of EGCG on BPH-1 cell migration were observed in a wound healing assay. Furthermore, it was determined by immunofluorescence labeling that EGCG disrupts F-actin organization and reduces paxillin distribution. Additionally, EGCG decreases the activation of FAK (Focal Adhesion Kinase) and the levels of paxillin, RhoA (Ras homolog gene family, member A), Cdc42 (cell division cycle 42) and PAK1 (p21 protein-activated kinase 1) in a dose-dependent manner.

SIGNIFICANCE

For the first time, by this study, we found evidence that BPH-1 cell proliferation could be inhibited with EGCG through the disruption of cytoskeleton organization and ECM interactions. Consequently, EGCG might be useful in the prevention and treatment of diseases characterized by excessive cell proliferation such as BPH.

The Influence of Androgen Deprivation Therapy on Prostate Size and Voiding Symptoms in Prostate Cancer Patients in Korea

Purpose

The goal of this study is to investigate the effects of androgen deprivation therapy (ADT) on total prostate volume and lower urinary tract symptoms (LUTS).

Methods

Between January 2007 and June 2014, 110 patients who received androgen deprivation treatment were enrolled in this retrospective study. Clinical parameters and urodynamic parameters along with changes at follow-up were analyzed. Factors such as reduction in prostate volume, changes in LUTS, and prostate volume tertiles were compared 1 year after ADT.

Results

After ADT, the total International Prostate Symptom Score (IPSS) score decreased from 17.45 to 12.21 and the IPSS voiding subscore decreased from 9.16 to 6.24. Maximal uroflow rate increased from 8.62 to 11.50 mL/sec and residual urine also reduced significantly by 29.34 mL. Change in prostate size was more prominent (–51.14%) in the patients with less than 1 year of ADT (n=21) than those who had more than 1 year of treatment (n=89, –44.12%). The decrease in the IPSS voiding subscore was greater within 1 year of ADT than after 1 year of treatment (–4.10 vs. –2.65). The differences were more significant in the 30–50 g group (n=59) and >50 g group (n=11) than the <30 g group (n=40) of the IPSS voiding subscore improvement (–3.76 , –4.91 vs. –2.10), and maximal uroflow rate improvement (2.78, 2.90 vs 1.49).

Conclusion

ADT resulted in statistically significant clinical improvement in terms of prostate volume, urodynamic parameters, and LUTS for patients with prostate cancer when analyzed by ADT duration and prostate volume.

Effects of hexanic extract of Serenoa repens (Permixon® 160 mg) on inflammation biomarkers in the treatment of lower urinary tract symptoms related to benign prostatic hyperplasia

BACKGROUND

Chronic prostatic inflammation (CPI) could be a cause of symptomatic or complicated benign prostatic hyperplasia (BPH). In previous in vitro and in vivo studies, Hexanic Extract of Serenoa repens (HESr) namely Permixon(®) has demonstrated potent anti-inflammatory properties. With the aim to provide new insight onto HESr anti-inflammatory properties in human we explore its effect on CPI biomarkers in men with lower urinary tract symptoms (LUTS) related to BPH using a non-invasive method and investigate links between biomarkers and clinical symptoms.

METHODS

An international, randomized, double-blind, parallel-group, tamsulosin-controlled study was carried out in 206 men with BPH-related LUTS. Patients received oral daily HESr 320mg or tamsulosin 0.4 mg during 3 months. The first urine stream after digital rectal examination (DRE) was collected at Day 1 and Day 90 and mRNA was extracted from prostatic epithelial cells desquaming in the lumen of the glands and seminal plasma fluid after DRE. mRNA quantification of the 29 most significant published inflammation markers in BPH and protein detection in urine was performed.

RESULTS

At D90, a decrease in mean gene expression was observed for 65.4% of the markers detected in the HESr group versus 46.2% in the tamsulosin group. In the 15 most frequently expressed genes, this difference was higher (80% vs. 33% respectively). Three proteins (MCP-1/CCL2, IP-10/CXCL10, and MIF) were detected. At D90, a decrease in the number of patients who expressed MCP-1/CCL2 and IP-10/CXCL10 was observed only in the HESr group. Moreover, MIF expression was significantly reduced by HESr compared with tamsulosin (P = 0.007). Finally, in contrast to tamsulosin, the subgroup of patients treated by HESr and who over expressed MIF at baseline, had a higher response to the International Prostate Symptom Score (I-PSS) than those who did not over express this protein (mean I-PSS change: -6.4 vs. -4.5 respectively). As the study is exploratory, results should be confirmed in a powered clinical study.

CONCLUSIONS

These results showed for the first time at clinical level the anti-inflammatory properties of HESr, already indicated in BPH-related LUTS. Thus, HESr could be of interest to prevent unfavourable evolution in patients with CPI.

In search of the molecular mechanisms mediating the inhibitory effect of the GnRH antagonist degarelix on human prostate cell growth

Degarelix is a gonadrotropin-releasing hormone (GnRH) receptor (GnRHR) antagonist used in patients with prostate cancer who need androgen deprivation therapy. GnRHRs have been found in extra-pituitary tissues, including prostate, which may be affected by the GnRH and GnRH analogues used in therapy. The direct effect of degarelix on human prostate cell growth was evaluated. Normal prostate myofibroblast WPMY-1 and epithelial WPE1-NA22 cells, benign prostatic hyperplasia (BPH)-1 cells, androgen-independent PC-3 and androgen-dependent LNCaP prostate cancer cells, as well as VCaP cells derived from a patient with castration-resistant prostate cancer were used. Discriminatory protein and lipid fingerprints of normal, hyperplastic, and cancer cells were generated by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS). The investigated cell lines express GNRHR1 and GNRHR2 and their endogenous ligands. Degarelix treatment reduced cell viability in all prostate cell lines tested, with the exception of the PC-3 cells; this can be attributed to increased apoptosis, as indicated by increased caspase 3/7, 8 and 9 levels. WPE1-NA22, BPH-1, LNCaP, and VCaP cell viability was not affected by treatment with the GnRH agonists leuprolide and goserelin. Using MALDI MS, we detected changes in m/z signals that were robust enough to create a complete discriminatory profile induced by degarelix. Transcriptomic analysis of BPH-1 cells provided a global map of genes affected by degarelix and indicated that the biological processes affected were related to cell growth, G-coupled receptors, the mitogen-activated protein kinase (MAPK) pathway, angiogenesis and cell adhesion. Taken together, these data demonstrate that (i) the GnRH antagonist degarelix exerts a direct effect on prostate cell growth through apoptosis; (ii) MALDI MS analysis provided a basis to fingerprint degarelix-treated prostate cells; and (iii) the clusters of genes affected by degarelix suggest that this compound, in addition to its known use in the treatment of prostate cancer, may be efficacious in BPH.

Inhibition of the signal transducer and activator of transcription 3 signaling pathway by Qianliening capsules suppresses the growth and induces the apoptosis of human prostate cells

The signal transducer and activator of transcription 3 (STAT3) pathway is one of the main growth factor‑mediated signal transduction pathways and is closely associated with the occurrence and development of benign prostatic hyperplasia (BPH). Qianliening capsules (QC) have significant therapeutic effects on BPH; however, the precise mechanism underlying its anti‑BPH activity remains to be elucidated. To further elucidate the molecular mechanism of the therapeutic effect of QC on BPH, the present study used epidermal growth factor (EGF), which has a role in the pathogenesis of BPH, to stimulate the growth of human prostate WPMY‑1 cells and activate the STAT3 pathway in the WPMY‑1 cells. The cell viability was determined using an MTT assay and the cell morphology was observed by phase‑contrast microscopy. Fluorescence activated cell sorting analysis with Annexin‑V/propidium iodide (PI) staining and PI staining were performed to examine cell apoptosis and the cell cycle. The activation of caspase‑9 and ‑3 were evaluated by colorimetric assay. STAT3 phosphorylation and transcriptional activity were detected by western blot analysis and the luciferase gene reporter, respectively. The mRNA and protein expression levels of B‑cell lymhoma 2 (Bcl‑2), Bcl‑2‑associated X protein (Bax), cyclin D1, cyclin‑dependent kinase 4 (CDK4) and p21 were measured by reverse transcription quantitative polymerase chain reaction and western blot analysis, respectively. In the present study, QC was found to significantly and dose‑dependently inhibit the EGF‑stimulated growth of WPMY‑1 cells, as evidenced by QC‑induced cell -morphological changes and a reduction in cell viability. In addition, QC treatment markedly induced the activation of caspase‑9 and ‑3. QC treatment also inhibited the EGF‑mediated increase of STAT3 phosphorylation levels and transcriptional activity in WPMY‑19 cells, accompanied by downregulation of the expression of Bcl‑2, cyclin D1 and CDK4 and upregulation of the expression of Bax and p21. These results suggested that QC effectively inhibited the proliferation and promoted the apoptosis of human prostate cells via modulation of the STAT3 signaling pathway and its target genes, which is likely to be one of the mechanisms underlying its activity in BPH treatment.

Preclinical therapy of benign prostatic hyperplasia with neuropeptide hormone antagonists

Benign prostatic hyperplasia (BPH) is a pathologic condition of the prostate described as a substantial increase in its number of epithelial and stromal cells. BPH may significantly reduce the quality of life due to the initiation of bladder outlet obstruction and lower urinary tract syndromes. Current medical therapies mostly consist of inhibitors of 5α-reductase or α₁-adrenergic blockers; their efficacy is often insufficient. Antagonistic analogs of neuropeptide hormones are novel candidates for the management of BPH. At first, antagonists of luteinizing hormone-releasing hormone (LHRH) have been introduced to the therapy aimed to reduce serum testosterone levels. However, they have also been found to produce an inhibitory activity on local LHRH receptors in the prostate as well as impotence and other related side effects. Since then, several preclinical and clinical studies reported the favorable effects of LHRH antagonists in BPH. In contrast, antagonists of growth hormone-releasing hormone (GHRH) and gastrin-releasing peptide (GRP) have been tested only in preclinical settings and produce significant reduction in prostate size in experimental models of BPH. They act at least in part, by blocking the action of respective ligands produced locally on prostates through their respective receptors in the prostate, and by inhibition of autocrine insulin-like growth factors-I/II and epidermal growth factor production. GHRH and LHRH antagonists were also tested in combination resulting in a cumulative effect that was greater than that of each alone. This article will review the numerous studies that demonstrate the beneficial effects of antagonistic analogs of LHRH, GHRH and GRP in BPH, as well as suggesting a potential role for somatostatin analogs in experimental therapies.

Androgen receptor and immune inflammation in benign prostatic hyperplasia and prostate cancer

Both benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are frequent diseases in middle-aged to elderly men worldwide. While both diseases are linked to abnormal growth of the prostate, the epidemiological and pathological features of these two prostate diseases are different. BPH nodules typically arise from the transitional zone, and, in contrast, PCa arises from the peripheral zone. Androgen deprivation therapy alone may not be sufficient to cure these two prostatic diseases due to its undesirable side effects. The alteration of androgen receptor-mediated inflammatory signals from infiltrating immune cells and prostate stromal/epithelial cells may play key roles in those unwanted events. Herein, this review will focus on the roles of androgen/androgen receptor signals in the inflammation-induced progression of BPH and PCa.

Hormonal manipulation of lower urinary tract symptoms secondary to benign prostatic obstruction

Although the etiology of lower urinary tract symptoms (LUTS) is often multifactorial, a significant proportion of men over the age of 50 suffer from benign prostatic obstruction (BPO) secondary to benign prostatic hyperplasia. Prostate, being an androgen responsive organ is dependent on the male sex hormone, testosterone, for growth. Thus, treatment strategies that manipulate the levels of circulating hormones that influence the level of testosterone and/or prostatic growth represent an important potential option for patients suffering with troublesome LUTS due to BPO. Despite this, the only hormonal treatment that is currently used in daily clinical practice is the 5-alpha reductase inhibitor. In this article, we review the current evidence on the use of the 5-alpha reductase inhibitors finasteride and dutasteride. We also discuss new emerging hormonal manipulation strategies for patients with LUTS secondary to BPO.

Degarelix versus goserelin plus bicalutamide therapy for lower urinary tract symptom relief, prostate volume reduction and quality of life improvement in men with prostate cancer: a systematic review and meta-analysis

OBJECTIVE

We performed a systematic review and meta-analysis to assess the efficacy and tolerability of degarelix for lower urinary tract symptom relief, prostate volume reduction and quality of life improvement in men with prostate cancer (PCa).

MATERIALS AND METHODS

A literature review was performed to identify all of the published randomized controlled trials (RCTs) that used degarelix versus gonadotropin-releasing hormone agonists plus antiandrogens therapy for the treatment of PCa. The search included the following databases: MEDLINE, EMBASE and the Cochrane Controlled Trials Register.

RESULTS

Three publications involving a total of 466 patients were used in the analysis, including three RCTs that compared degarelix with goserelin plus bicalutamide therapy for PCa over 12 weeks. For the comparison of degarelix with goserelin plus bicalutamide therapy, International Prostate Symptom Score (IPSS) reduction (standardized mean difference [SMD] = -1.85, 95% confidence interval [CI] = -2.97 to -0.72, p = 0.001) and IPSS ≥13 (SMD = -2.68, 95% CI = -4.57 to -0.78, p = 0.006) indicated that decreases in IPSS were greater in degarelix-treated patients than in goserelin plus bicalutamide-treated patients.

CONCLUSIONS

Our meta-analysis indicates that, compared with goserelin plus bicalutamide, degarelix has significantly more pronounced effects on lower urinary tract symptoms.

[New treatment strategies for male lower urinary tract symptoms]

For patients with lower urinary tract symptoms (LUTS), α1-adrenoreceptor inhibitors and 5-alpha reductase inhibitors as well as their combination are considered the gold standard. In addition, anticholinergic agents are being introduced as monotherapy or in combination with α1-adrenocepetor inhibitors for patients with predominant storage disorders. Phosphodiesterase 5 (PDE5) inhibitors are often the best option for patients with LUTS who also suffer from erectile dysfunction. Recently, novel treatment options have been presented and intraprostatic injection of various agents, such as botulinum toxin A, NX-1207 and PRX302 has shown promising initial results. In addition, innovative minimally invasive treatment options, such as UroLift® appear to be efficacious and safe in this patient cohort. Particular emphasis should be laid on patients with LUTS and concomitant sexual disorders.

Mechanisms of synergism between antagonists of growth hormone-releasing hormone and antagonists of luteinizing hormone-releasing hormone in shrinking experimental benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH) affects aging men. Combined therapy with antagonists of growth hormone-releasing hormone (GHRH) and of luteinizing hormone-releasing hormone (LHRH or GnRH) induces prostate shrinkage in rat models. We investigated the mechanisms of action of this combination on cell cycle traverse and expression of prostatic genes.

METHODS

Effects of GHRH antagonist, JMR-132 (40 µg/day), the LHRH antagonist, cetrorelix (0.625 mg/kg), and their combination were evaluated on testosterone-induced benign prostatic hyperplasia in male Wistar rats. Influence of JMR-132, cetrorelix, and their combinations on cell viability was assessed by MTS assay in BPH-1 human prostate epithelial cells and WPMY-1 normal prostate stromal cells. Cell cycle was analyzed by laser flow cytometry. Real-time PCR arrays were performed.

RESULTS

The combination of antagonists caused marked shrinkage of rat prostate (29.5%). In vitro, JMR-132 plus cetrorelix (both 5µM) produced synergistic (57.4%) inhibition of growth of BPH-1 cells, but a lesser inhibition (46%) of WPMY-1 cells. Co-treatment of with JMR-132 plus cetrorelix induced a significant increase of BPH-1 cells blocked in S-phase plus cells with lower G0 /G1 and G2 /M DNA content. Significant changes in expression of >40 gene transcripts related to growth factors, inflammatory cytokines, and signal transduction were identified.

CONCLUSIONS

GHRH antagonist and LHRH antagonist combination potentiates rat prostate weight reduction and synergistically inhibits of growth of BPH-1 leading to cell cycle arrest in S-phase. These effects were lesser in normal stromal prostate cell line, WPMY-1. Our findings suggest that GHRH antagonists could be useful for BPH therapy, possibly in combination with LHRH antagonists.

Hormonal manipulation of benign prostatic hyperplasia

PURPOSE OF REVIEW

We provide new viewpoints of hormonal control of benign prostatic hyperplasia (BPH). The latest treatment findings with 5-alpha reductase inhibitors (5-ARIs) finasteride and dutasteride, refined indications, efficacy, and safety are discussed and compared. We also discuss potential new 5-ARIs and other hormonal treatments.

RECENT FINDINGS

Finasteride and dutasteride have equal efficacy and safety for the treatment and prevention of progression of BPH. 5-ARIs are especially recommended for prostates greater than 40 ml and PSA greater than 1.5 ng/ml. Combination therapy is the treatment of choice in these patients, but with prostate volume greater than 58 ml or International Prostate Symptom Score of at least 20, combinations have no advantage over 5-ARI monotherapy. Updates on the recent developments on BPH therapy with luteinizing hormone-releasing hormone (LHRH) antagonist are also reviewed and analyzed. Preclinical studies suggest that growth hormone-releasing hormone (GHRH) antagonists effectively shrink experimentally enlarged prostates alone or in combination with LHRH antagonists.

SUMMARY

New 5-ARIs seem to be the promising agents that need further study. Preclinical studies revealed that GHRH and LHRH antagonists both can cause a reduction in prostate volume. Recent data indicate that prostate shrinkage is induced by the direct inhibitory action of GHRH and of LHRH antagonists exerted through prostatic receptors. The adverse effects of 5ARIs encourage alternative therapy.

[The efficacy of degarelix on LUTS (Lower urinary tract symptoms) relief in patients with prostate cancer]

Hormonal therapy is one of the treatment options for prostate cancer patients. There are many hormonal treatments modality to block the testosterone effect on prostate cancer cell proliferation. Degarelix is an innovative molecule able to antagonize the GnRH receptor with comparable oncological results to GnRH agonist, but with less side effects, avoiding the flare up phase, and better efficacy in LUTS relief. These characteristics of degarelix can impact on the clinical decision making to choose a therapy instead of another.

Mechanisms of prostate atrophy after LHRH antagonist cetrorelix injection: an experimental study in a rat model of benign prostatic hyperplasia

In the present study, we investigated the roles of TGF-β signaling pathway in a rat benign prostatic hyperplasia (BPH) model treated with cetrorelix. TGF-β1 and c-Myc expression were measured by qRT-PCR and Western blotting in the proximal and distal region of ventral prostatic lobes, respectively. We observed that treatment with cetrorelix led to a significant reduction of ventral prostate weight in a dose-dependent manner. In the proximal region, after cetrorelix treatment, the expression of TGF-β1 was dramatically increased (P<0.05), while the expression of c-Myc was significantly decreased (P<0.05). In comparison with the control group, the cetrorelix groups had more TUNEL-positive cells. Our findings strongly suggest that the TGF-β signaling pathway may be one of the major causes responsible for prostate volume reduction in BPH rats after cetrorelix treatment.

High fat-induced obesity associated with insulin-resistance increases FGF-2 content and causes stromal hyperplasia in rat ventral prostate

Obesity affects sex hormone secretion, which can negatively influence prostatic structure, homeostasis, and disease. This investigation aimed to evaluate the repercussions of obesity induced by a high-fat diet on the rat prostate, with or without treatment with the aromatase inhibitor, Letrozole. Adult Wistar rats were fed a high-fat diet (20% saturated fat, O) for 15 weeks to induce obesity or received a balanced diet (4% fat, C). Then, a group of C and O rats were daily treated with Letrozole (1 mg/kg b.w. per day) for 2 weeks (CL and OL, respectively). Subsequently, ventral prostate was processed for analysis by transmission electron microscopy, immunohistochemistry, and Western blotting. Obesity decreased 70% of the testosterone plasma level. The prostate showed epithelial atrophy and dilated acini in the intermediate portion and epithelial wrinkling in the distal tips. The relative frequency of smooth muscle α-actin in the O group increased by 67%. Ultrastructurally, epithelial cells in obese animals presented altered secretory organelles, lipid droplets, and thicker subjacent fibromuscular layer. Letrozole treatment caused a partial restoration of the prostatic changes caused by obesity. Obesity increased the prostatic content of fibroblast growth factor-2 (FGF-2) by 150%, and Letrozole treatment increased this protein even more in the control and obese groups. This investigation shows that obesity provokes structural and ultrastructural changes in the epithelium of rat prostate; these changes might affect gland homeostasis and physiology. The epithelial and smooth muscle cell hyperplasia and increased FGF-2 expression observed in this experimental model of obesity/insulin-resistance might explain the high frequency of benign prostatic hyperplasia in insulin-resistant men.

Androgen deprivation therapy for volume reduction, lower urinary tract symptom relief and quality of life improvement in patients with prostate cancer: degarelix vs goserelin plus bicalutamide

Study Type--Therapy (RCT) Level of Evidence 1b. What's known on the subject? and What does the study add? Androgen deprivation therapy (ADT) is commonly used as a primary treatment for patients with prostate cancer (PCa) who are not eligible for radical treatment options. ADT is also used in patients with PCa as neo-adjuvant hormone therapy to reduce prostate volume and down-stage the disease before radiotherapy with curative intent. The present study showed that ADT with the gonadotropin hormone-releasing hormone (GhRH) antagonist degarelix is non-inferior to combined treatment with the LHRH agonist goserelin and bicalutamide in terms of reducing prostate volume during the treatment period of 3 months. Degarelix treatment evokes, however, significantly better relief of lower urinary tract symptoms in patients having moderate and severe voiding problems.

OBJECTIVE

• To assess the efficacy of monthly degarelix treatment for reduction of total prostate volume (TPV), relief of lower urinary tract symptoms (LUTS) and improvement of quality of life (QoL) in patients with prostate cancer (PCa) using monthly goserelin as active control.

METHODS

• This was a randomized, parallel-arm, active-controlled, open-label, multicentre trial on 182 patients treated with either monthly degarelix (240/80 mg) or goserelin (3.6 mg) for 12 weeks. • For flare protection, goserelin-treated patients also received daily bicalutamide (50 mg) during the initial 28 days. • Key trial variables monitored monthly were TPV (primary endpoint), serum testosterone, prostate-specific antigen (PSA), the International Prostate Symptom Score (IPSS) and the Benign Prostate Hyperplasia Impact Index.

RESULTS

• In all, 175 patients completed the trial (96.1%). • At week 12, changes in TPV for degarelix and goserelin were similar (-37.2% vs -39.0%) and met the predefined non-inferiority criterion. • Decreases in IPSS were greater in degarelix than in goserelin-treated patients, differences being statistically significant in patients with baseline IPSS > 13 (-6.7 ± 1.8 vs -4.0 ± 1.0; P = 0.02). • The number of patients with an IPSS change of ≥ 3 over baseline was also significantly higher in patients treated with degarelix (61.0 vs 44.3%, P = 0.02). • Both treatments were safe and well tolerated.

CONCLUSIONS

• Medical castration reduces TPV and could also improve LUTS in patients with PCa. • While the short-term efficacy of degarelix and goserelin + bicalutamide was the same in terms of TPV reduction, degarelix showed superiority in LUTS relief in symptomatic patients, which could highlight the different actions of these drugs on extrapituitary gonadotrophin-releasing hormone (GnRH) receptors in the bladder and/or the prostate.

Combining growth hormone-releasing hormone antagonist with luteinizing hormone-releasing hormone antagonist greatly augments benign prostatic hyperplasia shrinkage

PURPOSE

Benign prostatic hyperplasia often affects aging men. Antagonists of the neuropeptide growth hormone-releasing hormone reduced prostate weight in an androgen induced benign prostatic hyperplasia model in rats. Luteinizing hormone-releasing hormone antagonists also produce marked, protracted improvement in lower urinary tract symptoms, reduced prostate volume and an increased urinary peak flow rate in men with benign prostatic hyperplasia. We investigated the influence of a combination of antagonists of growth hormone-releasing hormone and luteinizing hormone-releasing hormone on animal models of benign prostatic hyperplasia.

MATERIALS AND METHODS

We evaluated the effects of the growth hormone-releasing hormone antagonist JMR-132, given at a dose of 40 μg daily, the luteinizing hormone-releasing hormone antagonist cetrorelix, given at a dose of 0.625 mg/kg, and their combination on testosterone induced benign prostatic hyperplasia in adult male Wistar rats in vivo. Prostate tissue was examined biochemically and histologically. Serum levels of growth hormone, luteinizing hormone, insulin-like growth factor-1, dihydrotestosterone and prostate specific antigen were determined.

RESULTS

Marked shrinkage of the rat prostate (30.3%) occurred in response to the combination of growth hormone-releasing hormone and luteinizing hormone-releasing hormone antagonists (p<0.01). The combination strongly decreased prostatic prostate specific antigen, 6-transmembrane epithelial antigen of the prostate, interleukin-1β, nuclear factor-κβ and cyclooxygenase-2, and decreased serum prostate specific antigen.

CONCLUSIONS

A combination of growth hormone-releasing hormone antagonist with luteinizing hormone-releasing hormone antagonist potentiated a reduction in prostate weight in an experimental benign prostatic hyperplasia model. Results suggest that this shrinkage in prostate volume was induced by the direct inhibitory effects of growth hormone-releasing hormone and luteinizing hormone-releasing hormone antagonists exerted through their respective prostatic receptors. These findings suggest that growth hormone-releasing hormone antagonists and/or their combination with luteinizing hormone-releasing hormone antagonists should be considered for further development as therapy for benign prostatic hyperplasia.

Emerging treatment options for benign prostatic obstruction

Benign prostatic obstruction (BPO) affects an increasing number of men with age. It can cause troublesome lower urinary tract symptoms, can have a negative impact on quality of life, and may be associated with significant morbidity. Currently available medication and surgical treatments are limited by adverse events, invasiveness, and patient compliance. This has driven research into the pathogenesis of benign prostatic hyperplasia and led to the development of novel pharmacological agents and minimally invasive therapeutic interventions. This review highlights emerging treatment options for BPO.

Novel drug targets for the pharmacotherapy of benign prostatic hyperplasia (BPH)

Benign prostatic hyperplasia (BPH) is the major cause of lower urinary tract symptoms in men aged 50 or older. Symptoms are not normally life threatening, but often drastically affect the quality of life. The number of men seeking treatment for BPH is expected to grow in the next few years as a result of the ageing male population. Estimates of annual pharmaceutical sales of BPH therapies range from $US 3 to 10 billion, yet this market is dominated by two drug classes. Current drugs are only effective in treating mild to moderate symptoms, yet despite this, no emerging contenders appear to be on the horizon. This is remarkable given the increasing number of patients with severe symptoms who are required to undergo invasive and unpleasant surgery. This review provides a brief background on prostate function and the pathophysiology of BPH, followed by a brief description of BPH epidemiology, the burden it places on society, and the current surgical and pharmaceutical therapies. The recent literature on emerging contenders to current therapies and novel drug targets is then reviewed, focusing on drug targets which are able to relax prostatic smooth muscle in a similar way to the α(1) -adrenoceptor antagonists, as this appears to be the most effective mechanism of action. Other mechanisms which may be of benefit are also discussed. It is concluded that recent basic research has revealed a number of novel drug targets such as muscarinic receptor or P2X-purinoceptor antagonists, which have the potential to produce more effective and safer drug treatments.

LHRH antagonist Cetrorelix reduces prostate size and gene expression of proinflammatory cytokines and growth factors in a rat model of benign prostatic hyperplasia

BACKGROUND

Recent findings suggest that BPH has an inflammatory component. Clinical trials have documented that therapy with LHRH antagonist Cetrorelix causes a marked and prolonged improvement in LUTS in men with symptomatic BPH. We investigated the mechanism of action and effect of Cetrorelix in a rat model of BPH.

METHODS

Adult male Wistar rats were used. BPH was induced in rats by subcutaneous injections of TE 2 mg/day for 4 weeks. Control animals received injections of corn oil. After induction of BPH, rats received depot Cetrorelix pamoate at the doses of 0.625, 1.25, and 12.5 mg/kg on days 1 and 22 and TE-control rats received vehicle injections. Whole prostates were weighed and processed for RNA and protein. Real-time RT-PCR assays for numerous inflammatory cytokines and growth factors were performed. Quantitative analyses of prostatic LHRH receptor, LHRH, androgen receptor (AR) and 5α-reductase 2 were done by real-time RT-PCR and immunoblotting; serum DHT, LH, PSA, and IGF-1 by immunoassays.

RESULTS

mRNA levels for inflammatory cytokines IFN-γ, IL-3, IL-4, IL-5, IL-6, IL-8, IL-13, IL-15, and IL-17 and for growth factors EGF, FGF-2, FGF-7, FGF-8, FGF-14, TGF-β1, and VEGF-A were significantly reduced by Cetrorelix 0.625 mg/kg (P < 0.05). Prostate weights were also significantly lowered by any dose of Cetrorelix.

CONCLUSIONS

This study suggests that Cetrorelix reduces various inflammatory cytokines and growth factors in rat prostate and, at doses which do not induce castration levels of testosterone, can lower prostate weights. Our findings shed light on the mechanism of action of LHRH antagonists in BPH.

Receptors for luteinizing hormone-releasing hormone (LHRH) in benign prostatic hyperplasia (BPH) as potential molecular targets for therapy with LHRH antagonist cetrorelix

BACKGROUND

The majority of men will develop symptoms of benign prostatic hyperplasia (BPH) after 70 years of age. Various studies indicate that antagonists of LHRH, such as cetrorelix, exert direct inhibitory effects on BPH mediated by specific LHRH receptors. Our aim was to investigate the mRNA for LHRH and LHRH receptors and the expression of LHRH receptors in specimens of human BPH.

METHODS

The expression of mRNA for LHRH (n=35) and LHRH receptors (n=55) was investigated by RT-PCR in surgical specimens of BPH, using specific primers. The characteristics of binding sites for LHRH on 20 samples were determined by ligand competition assays. The LHRH receptor expression was also examined in 64 BPH specimens by immunohistochemistry.

RESULTS

PCR products for LHRH were found in 18 of 35 (51%) BPH tissues and mRNA for LHRH receptors was detected in 39 of 55 (71%) BPH specimens. Eighteen of 20 (90%) samples showed a single class of high affinity binding sites for [D-Trp(6) ]LHRH with a mean K(d) of 4.04 nM and a mean B(max) of 527.6 fmol/mg membrane protein. LHRH antagonist cetrorelix showed high affinity binding to LHRH receptors in BPH. Positive immunohistochemical reaction for LHRH receptors was present in 42 of 64 (67%) BPH specimens.

CONCLUSION

A high incidence of LHRH receptors in BPH supports the use of LHRH antagonists such as cetrorelix, for treatment of patients with lower urinary tract symptoms from BPH.

Effects of the gonadotropin-releasing hormone antagonist ganirelix on normal micturition and prostaglandin E(2)-induced detrusor overactivity in conscious female rats

BACKGROUND

Gonadotropin-releasing hormone (GnRH) antagonists have been reported to have beneficial effects on lower urinary tract symptoms in patients with benign prostatic hyperplasia.

OBJECTIVE

Our aim was to investigate the effects of ganirelix, a GnRH receptor antagonist, on bladder function and detrusor overactivity (DO) in female rats.

DESIGN, SETTING, AND PARTICIPANTS

Female Sprague-Dawley rats received 2 wk of daily systemic (0.1 mg/kg) or acute intravesical administration (IVES; 0.14 mg/l or 1.4 mg/l) ganirelix or vehicle (controls).

MEASUREMENTS

Assessments were obtained using cystometry in awake rats, organ bath studies, enzyme-linked immunosorbent assay, and western blot (WB).

RESULTS AND LIMITATIONS

Luteinising hormone levels were lower in rats treated systemically with ganirelix than in controls. No differences were observed in body or bladder weights. Micturition interval (MI), micturition volume (MV), residual volume, and bladder capacity (BC) were similar in both groups at baseline. No differences in urodynamic pressure parameters were observed between groups at baseline. Intravesical prostaglandin E(2) reduced MI, MV, and BC, and it increased basal pressure (BP), threshold pressure (TP), flow pressure (FP), and maximum pressure (MP) in all rats. MI, MV, and BC were reduced by 43%±4%, 50%±4%, and 43%±4% (controls) versus 22%±3%, 23%±3%, and 21%±3% (ganirelix-treated rats; p<0.001). TP and FP increased by 38%±8% and 30%±4% (controls) versus 16%±7% and 16%±5% (ganirelix; p<0.05). The maximal force of contractions for carbachol was larger in detrusor from ganirelix-treated rats (231% vs 177% of 60 mM K+-induced contractions). At 0.14 mg/l, but not 0.14 mg/l, IVES ganirelix increased MI, MV, and BC and decreased BP, TP, FP, and MP. In vitro, ganirelix had no effect on detrusor function. The gonadotropin-releasing hormone receptor was expressed (by WB) in the bladder mucosa.

CONCLUSIONS

Systemic treatment with ganirelix counteracted experimental DO in female rats. Because bladder preparations from these rats exhibited larger contractions to carbachol and because intravesical ganirelix affected both micturition intervals and urodynamic pressure profiles, a peripheral site of action of ganirelix in the urinary bladder cannot be excluded.

Antagonists of growth hormone-releasing hormone inhibit the proliferation of human benign prostatic hyperplasia cells

BACKGROUND

Growth hormone-releasing hormone (GHRH), besides stimulating the secretion of GH from the pituitary gland, acts as an autocrine/paracrine growth factor in many cancers. Antagonists of GHRH inhibit growth of experimental human tumors, but their effects on benign prostatic hyperplasia (BPH) have not been studied.

MATERIALS AND METHODS

We evaluated the effects of GHRH and GHRH antagonists JMR-132, MZ-5-156, MIA-601, and MIA-479 on the proliferation rate of human BPH-1 cells. We also measured by Western blot the influence of GHRH and GHRH antagonist JMR-132 on the expression of the PCNA and the activation of ERK1/2 and JAK/STAT3.

RESULTS

BPH-1 cells express GHRH and GHRH-receptor proteins. The proliferation rate of BPH-1 cells is increased by GHRH and inhibited by all the GHRH antagonists, the latest analogs MIA-601 and MIA-479 being the most potent. The stimulatory effect of GHRH is nullified by GHRH antagonists. GHRH strongly activates and GHRH antagonists significantly suppress the expression of the PCNA and the phosphorylation of ERK1/2 and JAK2/STAT3 pathways in these cells. Treatment with JAK2 inhibitor (AG490) decreases the proliferation rate of BPH-1 cells, and AG490 does nullify the effect of GHRH.

CONCLUSION

This study demonstrates for the first time that GHRH can act as a growth factor in BPH-1 cells and that GHRH antagonists can reverse its stimulatory effect. New observations are provided on the mechanism of action of GHRH antagonists in BPH. Our findings support the merit of further work on the development of GHRH antagonists for therapy of BPH.