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

Mechanisms and Efficacy of Chinese Herbal Medicines in Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) is one of the most common diseases in elderly men, the incidence of which gradually increases with age and leads to lower urinary tract symptoms (LUTS), which seriously affects the quality of life of patients. Chinese herbal medicines (CHMs) are widely used for the treatment of BPH in China and some other countries. To explore the molecular mechanisms of CHMs for BPH, we conducted a review based on peer-reviewed English-language publications in PubMed and Web of Science databases from inception to December 31, 2023. This article primarily reviewed 32 papers on the use of CHMs and its active compounds in the treatment of BPH, covering animal and cell experiments, and identified relevant mechanisms of action. The results suggest that the mechanisms of action of CHMs in treating BPH may involve the regulation of sex hormones, downregulation of cell growth factors, anti-inflammatory and antioxidative effects, inhibition of cell proliferation, and promotion of apoptosis. CHMs also exhibit α-blocker-like effects, with the potential to relax urethral smooth muscle and alleviate LUTS. Additionally, we also reviewed 4 clinical trials and meta-analyses of CHMs for the treatment of BPH patients, which provided initial evidence of the safety and effectiveness of CHMs treatment. CHMs treatment for BPH shows advantages as a multi-component, multi-target, and multi-pathway therapy, which can mitigate the severity of the disease, improve LUTS, and may become a reliable treatment option in the future.

Smooth muscle electromyography for detecting major alterations in the estrus cycle in rats

Determining the female animal cycle is crucial in preclinical studies and animal husbandry. Changes in hormone levels during the cycle affect physiological responses, including altered contractility of the visceral smooth muscle. The study aimed to identify estrus and anestrus using smooth muscle electromyographic (SMEMG) measurements, in vivo fluorescent imaging (IVIS) and in vitro organ contractility of the uterus and cecum. The study involved sexually mature female Sprague-Dawley rats, aged 10-12 weeks. The rats received a daily injection of cetrorelix acetate solution for 7 days, while another group served as the control. The animals were subjected to gastrointestinal and myometrial SMEMG. The change in αvβ3 integrin activity was measured with IVIS in the abdominal cavity. Contractility studies were performed in isolated organ baths using dissected uterus and cecum samples. Plasma samples were collected for hormone level measurements. A 3-fold increase in spontaneous contraction activity was detected in SMEMG measurements, while a significant decrease in αvβ3 integrin was measured in the IVIS imaging procedure. Cetrorelix reduced the level of LH and the progesterone / estradiol ratio, increased the spontaneous activity of the cecum rings, and enhanced KCl-evoked contractions in the uterus. We found a significant change in the rate of SMEMG signals, indicating simultaneous increases in the contraction of the cecum and the non-pregnant uterus, as evidenced by isolated organ bath results. Fluorescence imaging showed high levels of uterine αvβ3 integrin during the proestrus-estrus phase, but inhibiting the sexual cycle reduced fluorescence activity. Based on the results, the SMEMG and IVIS imaging methods are suitable for detecting estrus phase alterations in rats.

Origanum majorana L. Extract Attenuated Benign Prostatic Hyperplasia in Rat Model: Effect on Oxidative Stress, Apoptosis, and Proliferation

Benign prostatic hyperplasia (BPH) is a widespread androgenic illness influencing elderly men. It is distinguished by prostatic epithelial and stromal muscle cell proliferation. Inflammation, oxidative stress, and apoptosis have all been interrelated to the development of BPH. Marjoram (Origanum majorana L.) is a herb with reported antiproliferative, proapoptotic, and antioxidative properties, which have not yet been studied in relation to BPH. Consequently, in this work, an ethanolic extract of O. majorana was prepared in two doses (250 and 500 mg/kg/day) to be injected into castrated rats after induction of a testosterone-BPH model. Testosterone propionate (TP) was subcutaneously injected (0.5 mg/kg/day) for one week after castration to induce BPH. Forty adult Wistar male rats were randomly allocated into five groups: control, BPH model, high and low O. majorana doses (250, 500 mg/kg/day), and finasteride (FN) (0.8 mg/kg/day) as a positive control. Treatment was continued with drugs/normal saline for 28 days. Rat’s body and prostate were weighed, prostate index (PI) and % of prostate growth inhibition were calculated, serum dihydrotestosterone (DHT), prostatic content of superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (TAC), and malondialdehyde (MDA), DN damage, histopathological changes, immune expression of proliferating cell nuclear antigen (PCNA), caspase-3, α-SMA, and TGF-β1 were assessed. In addition, molecular quantitative PCR and ELISA analyses were performed to identify the expression of mRNAs and related proteins of both caspase-3 and TGF-β1 in prostate tissue from O. majorana-treated and untreated groups. Rats with BPH had significantly higher prostate weights and PI, higher DHT, DNA damage (8-hydroxyguanine, 8-OH-dG), and MDA levels with prominent PCNA, α-SMA, and TGF-β expression, but lower SOD, CAT, and TAC activity and caspase-3 expression. O. majorana (250 and 500 mg/kg/day)-treated groups revealed a decrease in prostate weights and PI, lower levels of DHT, suppressed oxidative stress, reduced tissue proliferation and fibrosis, and restored antioxidant and proapoptotic activity. Additionally, quantitative PCR and ELISA analysis showed that treatment with O. majorana significantly upregulated the expression of caspase-3 and downregulated the expression of TGF-β in prostate tissues of BPH rats. The data were confirmed by the immunohistological reactivity of these targeted markers in the prostate tissues. These effects were more significant with O. majorana 500 mg/mL/rat. In conclusion, the current study indicates the efficient use of O. majorana in the treatment of testosterone-induced BPH through its antiproliferative, proapoptotic, and antioxidative mechanisms.

Administration of Caesalpinia bonduc Seed Extracts Ameliorates Testosterone-Induced Benign Prostatic Hyperplasia (BPH) in Male Wistar Rats

Introduction

Benign prostatic hyperplasia (BPH) is a major chronic disease affecting men, and the therapeutic agents currently used to manage it have significant side effects. As a result, an alternative medicine with improved therapeutic properties with no side effects is desperately needed. The current investigation aims to study whether the Caesalpinia bonduc seed extracts (ethanolic-A, hydroalcoholic-B, and aqueous-C) have inhibitory potential on testosterone propionate (TP)-induced BPH in Wistar rats.

Methods

Wistar rats (male) were randomly allocated to one of five groups: control, BPH (TP-3 mg/kg, subcutaneously daily), low dose (TP + C. bonduc seed extracts – 200 mg/kg body weight), high dose (TP + C. bonduc seed extracts – 400 mg/kg body weight), and standard drug (TP + finasteride – 10 mg/kg body weight). At the end of drug treatment, the rats were sacrificed and their serum and prostates were taken for biochemical and histological studies.

Results

C. bonduc seed extracts treatment significantly decreased prostate weight and prostatic index in rats with TP-induced BPH. The seed extracts exhibited a potent inhibitory effect on dihydrotestosterone (DHT) in serum and prostate. In addition, the PSA level in the serum showed a noteworthy decrease in comparison with the BPH group. Histopathological examination also indicated that extracts improved the tissue morphology of the prostate significantly. Out of three extracts tested, ethanolic and hydroalcoholic extract recorded significant effect. Finally, liquid chromatography quadrupole time-of-flight mass spectrometry (LC/MS-QTOF) analysis showed that the major compounds present in the extracts were tocopherols, fucosterol, linoleic acid, β-amyrin, β-sitosterol, campesterol, cassane furanoditerpene, norcassane furanoditerpene and other diterpenes.

Conclusion

Thus, C. bonduc seed extracts could be a potential source for the formulation of new drug for managing BPH. To the best of our knowledge, this is the first scientific animal investigation into the use of C. bonduc seed extract for the management of BPH.

Amelioration of testosterone-induced benign prostatic hyperplasia using febuxostat in rats: The role of VEGF/TGFβ and iNOS/COX-2

Benign prostatic hyperplasia (BPH) is a common male disorder. Febuxostat is a non-purine, selective inhibitor of xanthine oxidase (XO), which has a strong antioxidant capacity and pleiotropic pharmacological properties. This study's objective was to explore the potential ameliorative effects of febuxostat against testosterone-induced BPH in rats. Febuxostat (10 mg/kg/day, per os [p.o.]) prevented increased prostate index levels, serum levels of prostate-specific antigen (PSA), and testosterone levels compared to animals treated with testosterone alone, when administered for 28 days. Histological examination indicated that febuxostat dramatically ameliorated pathological changes in the prostate architecture compared to the testosterone group. Similarly, febuxostat markedly improved testosterone-induced oxidative stress by inhibiting the increase in lipid peroxide and nitrite content, and by reducing the level of depletion of reduced glutathione (GSH) and superoxide dismutase (SOD) activity, which significantly reduced the prostate content of pro-inflammatory cytokines, including tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6). Furthermore, febuxostat significantly reduced the prostatic content, both in terms of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) messenger ribonucleic acid (mRNA) levels, and of protein levels. Moreover, compared to the testosterone group, febuxostat's beneficial effects prevented the increase in growth factors, comprising vascular endothelial cell growth factor A (VEGF-A) and transforming growth factor beta (TGF-β) protein levels. Its ameliorating effects were equal to those of finasteride, which is the most widely used remedy for BPH. In conclusion, this study provides novel evidence that febuxostat experimentally attenuates testosterone-induced BPH in rats, at least in part by inhibiting iNOS/COX-2 and VEGF/TGF-β pathways.

The FGF/FGFR system in the physiopathology of the prostate gland

Fibroblast growth factors (FGFs) are a family of proteins possessing paracrine, autocrine, or endocrine functions in a variety of biological processes, including embryonic development, angiogenesis, tissue homeostasis, wound repair, and cancer. Canonical FGFs bind and activate tyrosine kinase FGF receptors (FGFRs), triggering intracellular signaling cascades that mediate their biological activity. Experimental evidence indicates that FGFs play a complex role in the physiopathology of the prostate gland that ranges from essential functions during embryonic development to modulation of neoplastic transformation. The use of ligand- and receptor-deleted mouse models has highlighted the requirement for FGF signaling in the normal development of the prostate gland. In adult prostate, the maintenance of a functional FGF/FGFR signaling axis is critical for organ homeostasis and function, as its disruption leads to prostate hyperplasia and may contribute to cancer progression and metastatic dissemination. Dissection of the molecular landscape modulated by the FGF family will facilitate ongoing translational efforts directed toward prostate cancer therapy.

Inflammatory pathway employed by Red Maca to treat induced benign prostatic hyperplasia in rats

Benign prostatic hyperplasia (BPH) is a pathology characterised by an increase in prostate size associated with low urinary tract symptoms. Finasteride (F), a 5a-reductase inhibitor, is the standard treatment for BPH reducing prostate weight but also sexual desire. The Peruvian plant known as Red Maca (RM) (Lepidium meyenii) inhibits BPH in rats and mice. The aim of the study was to assess the inflammatory effect of RM and finasteride in rats with testosterone enanthate (TE)-induced BPH. Thirty rats were divided into 5 groups: Control, TE (50 mg/rat), TE + F (0.6 mg/kg), and two groups of TE + RM 40/80 (40 or 80 mg). After treatments, tumour necrosis factor alpha (TNFa), interleukin 4 (IL4) and interferon gamma (INFg) as well as testosterone and oestradiol were evaluated and inflammatory cells (neutrophils, mast cells and lymphocytes) in prostate were quantified. Red Maca and finasteride treatments decreased inflammatory cells counts in prostate, inhibiting TNFa by different pathways. Finasteride increased IL4 whereas Red Maca increased INFg. In conclusion, data suggest that finasteride acts on Th2 response by increasing IL4 in prostate, while Red Maca acts on Th1 response mediated by INFg.

The targeted LHRH analog AEZS-108 alters expression of genes related to angiogenesis and development of metastasis in uveal melanoma

Uveal melanoma (UM) is the most common malignant tumor of the eye. Recently, we have established that 46% of UM specimens express LHRH receptors. This finding supports the idea of a LHRH receptor-targeted therapy of UM patients. Cytotoxic analog of LHRH, AEZS-108 exhibits effective anti-cancer activity in LHRH-receptor positive cancers. AEZS-108 is a hybrid molecule, composed of a synthetic peptide carrier and the cytotoxic doxorubicin (DOX). In the present study, we investigated AEZS-108 induced cytotoxicity and the altered mRNA expression profile of regulatory factors related to angiogenesis and metastasis in LHRH receptor positive OCM3 cells. Our results show that AEZS-108 upregulates the expression of MASPIN/SERPINB5 tumor suppressor gene, which is downregulated in normal uvea and UM specimens independently from the LHRH receptor-ligand interaction. AEZS-108 also substantially downregulates hypoxia-inducible factor 1 alpha (HIF1A) expression. In order to investigate the mechanism of the induction of MASPIN by AEZS-108, OCM3 cells were treated with free DOX, D-Lys⁶ LHRH analog, or AEZS-108. qRT- PCR analysis revealed in OCM3 cells that AEZS-108 is a more potent inducer of MASPIN than free DOX. In conclusion, we show for the first time that AEZS-108 has a major impact in the regulation of angiogenesis thus plays a potential role in tumor suppression. Taken together, our results support the development of novel therapeutic strategies for UM focusing on LHRH receptors.

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.

Stimulation of Prostate Cells by the Senescence Phenotype of Epithelial and Stromal Cells: Implication for Benign Prostate Hyperplasia

Hyperproliferation of prostate transition‐zone epithelial and stromal cells leads to benign prostate hyperplasia (BPH), a prevalent pathology in elderly men. Senescent cells in BPH tissue induce a senescence‐associated secretory phenotype (SASP) which, by generating inflamed microenvironment and reactive stroma, promotes leukocyte infiltration, cellular hyperproliferation, and nodular prostate growth. We examined human prostate epithelial (BPH‐1, PNT‐1α) and stromal (HPS‐19I) cells for SASP induction by ionizing radiation and assessed SASP's impacts on cell proliferation and on signal transducers that promote cellular growth, proliferation, and survival. Radiation‐induced DNA damage led to cellular senescence, evident from elevated expression of senescence‐associated β‐galactosidase and the cell‐cycle inhibitor p16/INK4a. Clinical BPH tissue showed p16 accumulation. SASP induced mRNA expression for inflammatory cytokines (IL‐1α, IL‐6, IL‐8, TNF‐α); chemokines (GM‐CSF, CXCL12); metalloproteases (MMP‐1, MMP‐3, MMP‐10); growth factor binding IGFBP‐3. Media from irradiated epithelial or stromal cells enhanced BPH‐1 proliferation. ERK1/2 and AKT, which enhance cell growth/survival and STAT5, which facilitates cell cycle progression and leukocyte recruitment to epithelial microenvironment, were activated by SASP components. The radiation‐induced cellular senescence model can be a platform for identification of individual SASP components and pathways that drive BPH etiology/progression in vivo and targeting them may form the basis for novel BPH therapy.

The effects of Pueraria mirifica extract, diadzein and genistein in testosterone-induced prostate hyperplasia in male Sprague Dawley rats

Pueraria mirifica (PM) is a medicinal plant native to Thailand contained high amount of phytoestrogen and possesses anticancer activity. This study reports the effect of P. mirifica extract, phytoestrogen of diadzein and genistein for its benign prostate hyperplasia properties in testosterone-induced prostate hyperplasia in male Sprague Dawley rats. The P. mirifica extract was evaluated for its total phenols, flavonoid and antioxidant activity using DPPH, FRAP and metal chelating assay. The assessment of P. mirifica, diadzein and genistein against benign prostate hyperplasia was determined in testosterone-induced prostate hyperplasia in male Sprague Dawley rats. The total phenol was higher than flavonoid but showed low antioxidant activity of DPPH, FRAP and metal chelating. The aqueous PM extract at 1000 mg/kg significantly increased testosterone levels in testosterone-induced rats by 13% while diadzein and genistein increased it by 11% and 17% respectively. However, levels of FSH, LH, triglyceride and HDL are not affected by the oral administration of PM, diadzein and genistein to the rats. Similarly, total protein, albumin, globulin, total bilirubin, conjugated bilirubin, alkaline phosphatase, alanine aminotransferase, AST, and G-glutamyltransferase showed no significant difference as compared with negative control rats. The body weight of the rats, testis, kidney and liver showed no toxic effect. The zinc content increased significantly and the zinc transporter gen of ZnT4 and ZIP4 highly expressed suggesting that the PM, diadzein and genistein plays essential role in modulating prostate zinc homeostasis. Similarly, the expression of IL-6, AR and ER was significantly reduced indicating functioning in regulation of prostate growth and acts as anti-inflammatory role in preventing BPH. In conclusion, the results indicated that PM reduced BPH and contributed to the regulation in the zinc transport expression of the prostate cells in the benign prostate hyperplasia (BPH).

Epitestosterone- and testosterone-replacement in immature castrated rats changes main testicular developmental characteristics

Epitestosterone is the 17α-epimer of testosterone and has been described as an anti-androgen, since it inhibits the effects produced by testosterone and dihydrotestosterone via the nuclear androgen receptor (nAR). However, epitestosterone also displays an effect which is similar to the non-classical effect of testosterone, depolarizing the membrane potential of Sertoli cells and inducing a rapid Ca²⁺ uptake. This study aimed to investigate the effects of a treatment with epitestosterone on developmental parameters of immature rats. Animals were chemically castrated by using the gonadotropin-releasing hormone (GnRH) antagonist cetrorelix and then received a replacement of 7 days with epitestosterone or testosterone. Replacement with either epitestosterone or testosterone restored the anogenital distance (AGD) and testicular weight which had been reduced by chemical castration. The immunocontent of nAR and the nAR-immunoreactivity were reduced by epitestosterone treatment in the testis of both castrated and non-castrated animals. Furthermore, testosterone was unable of changing the membrane potential of Sertoli cells through its non-classical action in the group of animals castrated and replaced with epitestosterone. In conclusion, in relation to the level of protein expression of nAR epitestosterone acts as an anti-androgen. However, it acts in the same way as testosterone when genital development parameters are evaluated. Moreover, in castrated rats epitestosterone suppressed the non-classical response of testosterone, changing the pattern of testosterone signalling via a membrane mechanism in Sertoli cells.

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.

Discovery of LHRH and development of LHRH analogs for prostate cancer treatment

The discovery, isolation, elucidation of structure, synthesis, and initial testing of the neuropeptide hypothalamic luteinizing hormone-releasing hormone (LHRH), which regulates reproduction, is briefly described. The design, synthesis, and experimental and clinical testing of agonistic analogs of LHRH is extensively reviewed focusing on the development of new methods for the treatment of prostate cancer. Subsequent development of antagonistic analogs of LHRH is then faithfully recounted with special emphasis on therapy of prostate cancer and BPH. The concepts of targeted therapy to peptide receptors on tumors are re-examined and the development of the cytotoxic analogs of LHRH and their status is reviewed. The endeavor to develop better therapies for prostate cancer, based on LHRH analogs, guided much of our work.

Approach to Androgen Deprivation in the Prostate Cancer Patient with Pre-existing Cardiovascular Disease

PURPOSE OF REVIEW

Androgen deprivation therapy (ADT) is a mainstay of treatment for advanced prostate cancer. Several studies have reported an association between ADT and an increase in cardiovascular events, especially in those receiving gonadotropin-releasing hormone (GnRH) agonists compared to GnRH antagonists. We review the body of literature reporting the association of ADT and cardiovascular morbidity, and discuss the proposed mechanism of cardiovascular disease due to ADT including metabolic changes that may promote atherosclerosis and local hormonal effects that may increase plaque rupture and thrombosis.

RECENT FINDINGS

GnRH agonists appear to increase the risk of cardiovascular morbidity by 20-25% in men on these agents compared those who do not receive ADT. GnRH antagonists may appear to have halve this risk while improving PSA progression-free survival. GnRH antagonists may be superior to GnRH agonists for patients with significant cardiovascular disease, significant metastatic disease burden, or severe lower urinary tract symptoms.

Antagonists of growth hormone-releasing hormone inhibit proliferation induced by inflammation in prostatic epithelial cells

The etiology of benign prostatic hyperplasia (BPH) is multifactorial, and chronic inflammation plays a pivotal role in its pathogenesis. Growth hormone-releasing hormone (GHRH) is a hypothalamic neuropeptide that has been shown to act as paracrine/autocrine factor in various malignancies including prostate cancer. GHRH and its receptors are expressed in experimental models of BPH, in which antagonists of GHRH suppressed the levels of proinflammatory cytokines and altered the expression of genes related to epithelial-to-mesenchymal transition (EMT). We investigated the effects of GHRH antagonist on prostatic enlargement induced by inflammation. Autoimmune prostatitis in Balb/C mice was induced by a homogenate of reproductive tissues of male rats. During the 8-wk induction of chronic prostatitis, we detected a progressive increase in prostatic volume reaching 92% at week 8 compared with control (P < 0.001). Daily treatment for 1 mo with GHRH antagonist MIA-690 caused a 30% reduction in prostate volume (P < 0.05). Conditioned medium derived from macrophages increased the average volume of spheres by 82.7% (P < 0.001) and elevated the expression of mRNA for N-cadherin, Snail, and GHRH GHRH antagonist reduced the average volume of spheres stimulated by inflammation by 75.5% (P < 0.05), and TGF-β2 by 91.8% (P < 0.01). The proliferation of primary epithelial cells stimulated by IL-17A or TGF-β2 was also inhibited by 124.1% and 69.9%, respectively. GHRH stimulated the growth of BPH-1 and primary prostate spheres. This study provides evidence that GHRH plays important roles in prostatic inflammation and EMT and suggests the merit of further investigation to elucidate the effects of GHRH antagonists in prostatitis and 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.

Potentiating effects of GHRH analogs on the response to chemotherapy

Growth hormone releasing hormone (GHRH) from hypothalamus nominatively stimulates growth hormone release from adenohypophysis. GHRH is also produced by cancers, acting as an autocrine/paracrine growth factor. This growth factor function is seen in lymphoma, melanoma, colorectal, liver, lung, breast, prostate, kidney, bladder cancers. Pituitary type GHRH receptors and their splice variants are also expressed in these malignancies. Synthetic antagonists of the GHRH receptor inhibit proliferation of cancers. Besides direct inhibitory effects on tumors, GHRH antagonists also enhance cytotoxic chemotherapy. GHRH antagonists potentiate docetaxel effects on growth of H460 non-small cell lung cancer (NSCLC) and MX-1 breast cancer plus suppressive action of doxorubicin on MX-1 and HCC1806 breast cancer. We investigated mechanisms of antagonists on tumor growth, inflammatory signaling, doxorubicin response, expression of drug resistance genes, and efflux pump function. Triple negative breast cancer cell xenografted into nude mice were treated with GHRH antagonist, doxorubicin, or their combination. The combination reduced tumor growth, inflammatory gene expression, drug-resistance gene expression, cancer stem-cell marker expression, and efflux-pump function. Thus, antagonists increased the efficacy of doxorubicin in HCC1806 and MX-1 tumors. Growth inhibition of H460 NSCLC by GHRH antagonists induced marked downregulation in expression of prosurvival proteins K-Ras, COX-2, and pAKT. In HT-29, HCT-116 and HCT-15 colorectal cancer lines, GHRH antagonist treatment caused cellular arrest in S-phase of cell cycle, potentiated inhibition of in vitro proliferation and in vivo growth produced by S-phase specific cytotoxic agents, 5-FU, irinotecan and cisplatin. This enhancement of cytotoxic therapy by GHRH antagonists should have clinical applications.

New therapies for relapsed castration-resistant prostate cancer based on peptide analogs of hypothalamic hormones

It is a pleasure to contribute our presentation at the International Prostate Forum of the Annual Meeting of the American Urological Association (AUA) to this special issue of the Asian Journal of Andrology.

Inhibitory effect of curcumin on testosterone induced benign prostatic hyperplasia rat model

Background

Benign prostatic hyperplasia (BPH) is one of the common male diseases, which is provoked by dihydrotestosterone (DHT) and androgen signals. Several studies showed that curcumin has various effects of prevention and treatment to diseases. We investigated whether curcumin may repress the development of BPH in male Wistar rats.

Methods

Seven weeks male Wistar rats were and divided into 4 groups (normal group, BPH group, finasteride group, curcumin group; n = 8 for each group). In order to induce BPH in rats, rats were castrated and testosterone was injected subcutaneously everyday (s.c., 20 mg/kg). Rats in the curcumin group were treated 50 mg/kg, administered orally for 4 weeks. After 4 weeks, all rats were sacrificed and their prostate and serum were analyzed.

Results

Compared to the finasteride group as positive group, the curcumin group showed similarly protective effect on BPH in histopathologic morphology, prostate volume. Results of immunohistochemistry and western-blot showed decreased expressions of VEGF, TGF-ß1, and IGF1 were also decreased in the curcumin group.

Conclusions

These results suggested that curcumin inhibited the development of BPH and might a useful herbal treatment or functional food for BPH.

Rapid Anti-Inflammatory Effects of Gonadotropin-Releasing Hormone Antagonism in Rheumatoid Arthritis Patients with High Gonadotropin Levels in the AGRA Trial

Objectives

Gonadotropin-releasing hormone (GnRH) and pituitary gonadotropins, which appear to be proinflammatory, undergo profound secretory changes during events associated with rheumatoid arthritis (RA) onset, flares, or improvement e.g. menopausal transition, postpartum, or pregnancy. Potential anti-inflammatory effects of GnRH-antagonists may be most pronounced in patients with high GnRH and gonadotropin levels. Therefore, we investigated the efficacy and safety of a GnRH-antagonist, cetrorelix, in RA patients with high gonadotropin levels.

Methods

We report intention-to-treat post hoc analyses among patients with high gonadotropin levels (N = 53), i.e. gonadotropin levels>median, from our proof-of-concept, double-blind AGRA-study (N = 99). Patients with active longstanding RA, randomized to subcutaneous cetrorelix (5mg days1–2; 3mg days 3–5) or placebo, were followed through day 15. Only predefined primary and secondary endpoints were analyzed.

Results

The primary endpoint, Disease Activity Score of 28-joint counts with C-reactive protein (DAS28-CRP), improved with cetrorelix compared with placebo by day 5 (-1.0 vs. -0.4, P = 0∙010). By day 5, more patients on cetrorelix achieved at least a 20% improvement in the American College of Rheumatology scale (44% vs. 19%, P = 0.049), DAS28-CRP≤3.2 (24% vs. 0%, P = 0.012), and European League against Rheumatism ‘Good-responses’ (19% vs. 0%, P = 0.026). Tumor necrosis factor-α, interleukin-1β, interleukin-10, and CRP decreased with cetrorelix (P = 0.045, P = 0.034, P = 0.020 and P = 0.042 respectively) compared with placebo by day 15. Adverse event rates were similar between groups.

Conclusions

GnRH-antagonism produced rapid anti-inflammatory effects in RA patients with high gonadotropin levels. GnRH should be investigated further in RA.

Trial Registration

ClinicalTrials.gov NCT00667758

Targeted cytotoxic analog of luteinizing hormone-releasing hormone (LHRH), AEZS-108 (AN-152), inhibits the growth of DU-145 human castration-resistant prostate cancer in vivo and in vitro through elevating p21 and ROS levels

Management of castration-resistant prostate cancer (CRPC) is challenging due to lack of efficacious therapy. Luteinizing hormone-releasing hormone (LHRH) analogs appear to act directly on cells based on the LHRH receptors on human prostate adenocarcinoma cells. We explored anticancer activity of a cytotoxic analog of LHRH, AEZS-108, consisting of LHRH agonist linked to doxorubicin. Nude mice bearing DU-145 tumors were used to compare antitumor effects of AEZS-108 with its individual constituents or their unconjugated combination. The tumor growth inhibition of conjugate was greatest among treatment groups (90.5% inhibition vs. 41% by [D-Lys(6)]LHRH+DOX). The presence of LHRH receptors on DU-145 cells was confirmed by immunocytochemistry. In vitro, AEZS-108 significantly inhibited cell proliferation (61.2% inhibition) and elevated apoptosis rates (by 46%). By the detection of the inherent doxorubicin fluorescence, unconjugated doxorubicin was seen in the nucleus; the conjugate was perinuclear and at cell membrane. Autophagy, visualized by GFP-tagged p62 reporter, was increased by AEZS-108 (7.9-fold vs. 5.3-fold by DOX+[D-Lys(6)]LHRH. AEZS-108 more effectively increased reactive oxygen species (ROS, 2-fold vs. 1.4-fold by DOX+[D-Lys(6)]LHRH) and levels of the apoptotic regulator p21 in vivo and in vitro. We demonstrate robust inhibitory effects of the targeted cytotoxic LHRH analog, AEZS-108, on LHRHR positive castration-resistant prostate cancer cells.

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.

Flaxseed suppressed prostatic epithelial proliferation in a rat model of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH), a disease occurring frequently among elderly males, is a slow progressive enlargement of the fibromuscular and epithelial structures of the prostate gland. Dietary factors may influence the prostate and exert an influence on prostatic growth and disease. The current study was undertaken to investigate the protective effect of dietary flaxseed supplementation against testosterone-induced prostatic hyperplasia in male rats. Forty male Wistar rats were divided into 5 groups: (1) untreated control; (2) treatment with testosterone propionate (TP) to induce prostate enlargement; (3) TP-treated group fed a diet containing 5% milled flaxseed; (4) TP-treated group fed a diet containing 10% milled flaxseed; and (5) TP-treated group fed a diet containing 20 ppm finasteride. Treatment with TP significantly increased the absolute and relative weights of different prostatic lobes, serum testosterone (T), and testosterone/estradiol ratio, as well as prostatic vascular endothelial growth factor (VEGF) expression, RNA synthesis per cell, and epithelial cell proliferation, detected as Ki67 labeling. Histopathological examination did not reveal marked differences in acinar morphology in ventral prostate, whereas morphometric analysis showed significantly increased epithelial cell height. Co-administration of flaxseed or finasteride with TP significantly reduced prostatic VEFG, epithelial cell proliferation, and RNA/DNA ratio, along with a significant increase in serum T and testosterone/estradiol ratio compared with TP-only-treated rats. Our results indicate that flaxseed, similar to the 5α-reductase inhibitor finasteride, blocked TP-induced prostate enlargement in a rat model of BPH, likely through suppression of prostatic VEFG and cellular proliferation.

Cooperative effects of EGF, FGF, and TGF-β1 in prostate stromal cells are different from responses to single growth factors

AIMS

Stromal growth is critical for prostate enlargement during benign prostatic hyperplasia (BPH). While responses of prostate cells to single growth factors have been well characterized, responses to multiple growth factors at once are poorly understood. Here, we examined the effects of combinations between epidermal growth factor (EGF), fibroblast growth factor (FGF), and transforming growth factor-β1 (TGF-β1) in human prostate stromal cells.

MAIN METHODS

EGF, FGF, and TGF-β1 were applied to WPMY-1 cells, an immortalized, non-malignant line of stromal cells from the human prostate. Hypertrophic responses were assessed by protein/DNA ratio, and cyclin D1 mRNA by RT-PCR. Expression of EGF, FGF, and TGF-β1 and their receptors in human prostate tissue was analyzed by RT-PCR, Western blot, and fluorescence staining.

KEY FINDINGS

Hypertrophic responses to single growth factors and combinations were similar. Combinations showed additive effects on cyclin D1 mRNA. Combination of EGF with TGF-β1, but not EGF or TGF-β1 alone, caused assembly of cells to a new two-dimensional structure, being characterized by dense aggregates connected by branches of few cells. EGF and TGF-β1 were detected together in human prostates. Receptors for EGF and TGF-β colocalized on stromal cells in human prostates.

SIGNIFICANCE

Responses of prostate stromal cells to combinations of EGF, FGF, and TGF-β1 may be quantitatively different, qualitatively different, or similar to responses to single growth factors. The combination of EGF and TGF-β1, but not EGF or TGF-β1 alone, induces aggregation of prostate stromal cells, which may be relevant for morphogenesis.

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.

Inhibitors of apoptosis proteins in experimental benign prostatic hyperplasia: effects of serenoa repens, selenium and lycopene

BACKGROUND

The apoptosis machinery is a promising target against benign prostatic hyperplasia (BPH). Inhibitors of apoptosis proteins (IAPs) modulate apoptosis by direct inhibition of caspases. Serenoa Repens (SeR) may be combined with other natural compounds such as Lycopene (Ly) and Selenium (Se) to maximize its therapeutic activity in BPH. We investigated the effects of SeR, Se and Ly, alone or in association, on the expression of four IAPs, cIAP-1, cIAP-2, NAIP and survivin in rats with experimental testosterone-dependent BPH. Moreover, caspase-3, interleukin-6 (IL-6) and prostate specific membrane antigen (PSMA) have been evaluated.Rats were administered, daily, with testosterone propionate (3 mg/kg/sc) or its vehicle for 14 days. Testosterone injected animals (BPH) were randomized to receive vehicle, SeR (25 mg/kg/sc), Se (3 mg/kg/sc), Ly (1 mg/kg/sc) or the SeR-Se-Ly association for 14 days. Animals were sacrificed and prostate removed for analysis.

RESULTS

BPH animals treated with vehicle showed unchanged expression of cIAP-1 and cIAP-2 and increased expression of NAIP, survivin, caspase-3, IL-6 and PSMA levels when compared with sham animals. Immunofluorescence studies confirmed the enhanced expression of NAIP and survivin with a characteristic pattern of cellular localization. SeR-Se-Ly association showed the highest efficacy in reawakening apoptosis; additionally, this therapeutic cocktail significantly reduced IL-6 and PSMA levels. The administration of SeR, Se and Ly significantly blunted prostate overweight and growth; moreover, the SeR-Se-Ly association was most effective in reducing prostate enlargement and growth by 43.3% in treated animals.

CONCLUSIONS

The results indicate that IAPs may represent interesting targets for drug therapy of BPH.

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.

Powerful inhibition of experimental human pancreatic cancers by receptor targeted cytotoxic LH-RH analog AEZS-108

Pancreatic carcinoma is one of the cancers with the worse prognosis, thus any therapeutic improvement is imperative. Cytotoxic LH-RH analog, AN-152 (proprietary designation, AEZS-108), consisting of doxorubicin (DOX) conjugated to D-Lys⁶LH-RH, is now in clinical trials for targeted therapy of several sex hormone-dependent tumors that express LH-RH receptors. We investigated LH-RH receptors in human pancreatic carcinoma and the effects of AN-152 (AEZS-108) on experimental pancreatic cancers. We determined LH-RH receptor presence in human pancreatic cancer samples by immunohistochemistry and, in three human pancreatic cancer lines (SW-1990, Panc-1 and CFPAC-1), by binding assays and Western blotting. The effects of the cytotoxic LH-RH analog were investigated on growth of these same cancer lines xenografted into nude mice. We also analyzed differences between the antitumor effects of the cytotoxic analog and its cytotoxic radical alone, doxorubicin (DOX), on the expression of cancer-related genes by PCR arrays. LH-RH receptors were expressed in two randomly selected surgically removed human pancreatic cancer samples and in all three cancer lines. Cytotoxic LH-RH analogs powerfully inhibited growth of all three tumor lines in nude mice; AN-152 was significantly stronger than DOX on Panc-1 and CFPAC-1 cancers. PCR array showed that cytotoxic LH-RH analog AN-152 affected the expression of genes associated with cellular migration, invasion, metastasis and angiogenesis more favorably than DOX, however the changes in gene expression varied considerably among the three cancer lines. Cytotoxic LH-RH analog, AEZS-108, may be a useful agent for the treatment of LH-RH receptor positive advanced pancreatic carcinoma.

Preclinical efficacy of growth hormone-releasing hormone antagonists for androgen-dependent and castration-resistant human prostate cancer

Advanced hormone-sensitive prostate cancer responds to androgen-deprivation therapy (ADT); however, therapeutic options for recurrent castration-resistant disease are limited. Because growth hormone-releasing hormone (GHRH) and GHRH receptor (GHRH-R) are regulated in an autocrine fashion in prostate cancer, inhibition of GHRH-R represents a compelling approach to treatment. We investigated the effects of the latest series of improved, highly potent GHRH antagonists--MIA-602, MIA-606, and MIA-690--on the growth of androgen-dependent as well as castration-resistant prostate cancer (CRPC) cells in vitro and in vivo. GHRH-R and its splice variant, SV1, were present in 22Rv1, LNCaP, and VCaP human prostate cancer cell lines. Androgen-dependent LNCaP and VCaP cells expressed higher levels of GHRH-R protein compared with castration-resistant 22Rv1 cells; however, 22Rv1 expressed higher levels of SV1. In vitro, MIA-602 decreased cell proliferation of 22Rv1, LNCaP, and VCaP prostate cancer cell lines by 70%, 61%, and 20%, respectively (all P < 0.05), indicating direct effects of MIA-602. In vivo, MIA-602 was more effective than MIA-606 and MIA-690 and decreased 22Rv1 xenograft tumor volumes in mice by 63% after 3 wk (P < 0.05). No noticeable untoward effects or changes in body weight occurred. In vitro, the VCaP cell line was minimally inhibited by MIA-602, but in vivo, this line showed a substantial reduction in growth of xenografts in response to MIA-602, indicating both direct and systemic inhibitory effects. MIA-602 also further inhibited VCaP xenografts when combined with ADT. This study demonstrates the preclinical efficacy of the GHRH antagonist MIA-602 for treatment of both androgen-dependent and CRPC.

Androgens regulate prostate cancer cell growth via an AMPK-PGC-1α-mediated metabolic switch

Prostate cancer is the most commonly diagnosed malignancy among men in industrialized countries, accounting for the second leading cause of cancer-related deaths. Although we now know that the androgen receptor (AR) is important for progression to the deadly advanced stages of the disease, it is poorly understood what AR-regulated processes drive this pathology. Here we demonstrate that AR regulates prostate cancer cell growth via the metabolic sensor 5'-AMP-activated protein kinase (AMPK), a kinase that classically regulates cellular energy homeostasis. In patients, activation of AMPK correlated with prostate cancer progression. Using a combination of radiolabeled assays and emerging metabolomic approaches, we also show that prostate cancer cells respond to androgen treatment by increasing not only rates of glycolysis, as is commonly seen in many cancers, but also glucose and fatty acid oxidation. Importantly, this effect was dependent on androgen-mediated AMPK activity. Our results further indicate that the AMPK-mediated metabolic changes increased intracellular ATP levels and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)-mediated mitochondrial biogenesis, affording distinct growth advantages to the prostate cancer cells. Correspondingly, we used outlier analysis to determine that PGC-1α is overexpressed in a subpopulation of clinical cancer samples. This was in contrast to what was observed in immortalized benign human prostate cells and a testosterone-induced rat model of benign prostatic hyperplasia. Taken together, our findings converge to demonstrate that androgens can co-opt the AMPK-PGC-1α signaling cascade, a known homeostatic mechanism, to increase prostate cancer cell growth. The current study points to the potential utility of developing metabolic-targeted therapies directed toward the AMPK-PGC-1α signaling axis for the treatment of prostate cancer.

Inhibition of U-87 MG glioblastoma by AN-152 (AEZS-108), a targeted cytotoxic analog of luteinizing hormone-releasing hormone

Glioblastoma multiforme is the most frequent tumor of the central nervous system in adults and has a dismal clinical outcome, which necessitates the development of new therapeutic approaches. We investigated in vivo the action of the targeted cytotoxic analog of luteinizing hormone releasing hormone, AN-152 (AEZS-108) in nude mice (Ncr nu/nu strain) bearing xenotransplanted U-87 MG glioblastoma tumors. We evaluated in vitro the expression of LHRH receptors, proliferation, apoptosis and the release of oncogenic and tumor suppressor cytokines. Clinical and U-87 MG samples of glioblastoma tumors expressed LHRH receptors. Treatment of nude mice with AN-152, once a week at an intravenous dose of 413 nmol/20g, for six weeks resulted in 76 % reduction in tumor growth. AN-152 nearly completely abolished tumor progression and elicited remarkable apoptosis in vitro. Genomic (RT-PCR) and proteomic (ELISA, Western blot) studies revealed that AN-152 activated apoptosis, as reflected by the changes in p53 and its regulators and substrates, inhibited cell growth, and elicited changes in intermediary filament pattern. AN-152 similarly reestablished contact regulation as demonstrated by expression of adhesion molecules and inhibited vascularization, as reflected by the transcription of angiogenic factors. Our findings suggest that targeted cytotoxic analog AN-152 (AEZS-108) should be considered for a treatment of glioblastomas.

Androgen deprivation decreases prostate specific antigen in the absence of tumor: implications for interpretation of PSA results

Background: Prostate-specific antigen (PSA) is used as an outcome measure for relapsed disease in prostate cancer. Nonetheless, there are considerable concerns about its indiscriminate use as a surrogate endpoint for cell growth or survival. We hypothesized that treatment with a luteinizing hormone releasing hormone (LHRH) analog would decrease PSA levels even in the absence of malignant disease.

Methods: We determined testosterone and PSA levels in 30 healthy volunteers after a single intramuscular injection of a LHRH depot formulation. Testosterone and PSA levels were quantified by radioimmunoassay and electrochemi-luminescence immunoassay, respectively.

Results: After an initial flare-up during the first 3 days testosterone decreased reaching castration levels in 18 of the 30 young men (60%). After the nadir on day 28, testosterone levels increased to normal again. Changes in PSA paralleled those of testosterone. Castration reduced PSA levels by 29% (95% CI 19%–39%) compared to baseline (p<0.0001).

Conclusions: LHRH superagonists decrease PSA levels by testosterone deprivation. Conferring these findings to tumor patients, decreases in PSA after treatment with LHRH analogs might not only reflect disease regression but also a direct testosterone mediated effect on PSA. Thus, PSA levels should be cautiously interpreted when patients receive hormonal therapy.

Agonists of luteinizing hormone-releasing hormone in prostate cancer

INTRODUCTION

Androgen deprivation therapy (ADT) has been the first-line standard of care for treating patients with hormone-sensitive advanced prostate cancer (PCa) for many decades. The agonists of luteinizing hormone-releasing hormone (LHRH), also called gonadotropin-releasing hormone, are still the most frequently used form of medical ADT.

AREAS COVERED

This article reviews the available data and most recent information concerning the use of LHRH agonists in advanced PCa. This article also reviews the discovery and development of LHRH agonists and summarizes the clinical evidence for their efficacy in PCa.

EXPERT OPINION

The introduction and application of agonists of LHRH has modernized and improved the treatment of advanced PCa. The life-saving benefits of LHRH agonists are well established, yet underestimated. Despite their efficacy, agonists of LHRH have several disadvantages or drawbacks including disease flare. The approach to ADT has been recently further refined with the development of the LHRH antagonist degarelix. Degarelix, a highly clinically effective third-generation LHRH antagonist, is currently available in most countries for therapy of advanced PCa. This new drug offers attractive alternatives to LHRH agonists for treatment of advanced PCa. A therapy for castration-resistant PCa based on a targeted cytotoxic analog of LHRH, AEZS-108, is also emerging.

[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.

Anti-tumor effects of peptide analogs targeting neuropeptide hormone receptors on mouse pheochromocytoma cells

Pheochromocytoma is a rare but potentially lethal chromaffin cell tumor with currently no effective treatment. Peptide hormone receptors are frequently overexpressed on endocrine tumor cells and can be specifically targeted by various anti-tumor peptide analogs. The present study carried out on mouse pheochromocytoma cells (MPCs) and a more aggressive mouse tumor tissue-derived (MTT) cell line revealed that these cells are characterized by pronounced expression of the somatostatin receptor 2 (sst2), growth hormone-releasing hormone (GHRH) receptor and the luteinizing hormone-releasing hormone (LHRH) receptor. We further demonstrated significant anti-tumor effects mediated by cytotoxic somatostatin analogs, AN-162 and AN-238, by LHRH antagonist, Cetrorelix, by the cytotoxic LHRH analog, AN-152, and by recently developed GHRH antagonist, MIA-602, on MPC and for AN-152 and MIA-602 on MTT cells. Studies of novel anti-tumor compounds on these mouse cell lines serve as an important basis for mouse models of metastatic pheochromocytoma, which we are currently establishing.

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.

Combination of GHRH antagonists and docetaxel shows experimental effectiveness for the treatment of triple-negative breast cancers

In preclinical studies, antagonists of growth hormone-releasing hormone (GHRH) have demonstrated inhibitory effects on the growth of various types of cancers expressing the pituitary type of GHRH receptors (pGHRH-R) and/or its active splice variant 1 (SV1). In this study, we investigated the effectiveness of the treatment of MDA-MB-231 human triple-negative breast cancer (TNBC) with GHRH antagonist JMR-132 alone or in combination with docetaxel. Receptor expression in the MDA-MB-231 human breast cancer cell line was evaluated by reverse transcription-polymerase chain reaction (RT-PCR). Cell viability assays were performed on MDA-MB-231 cells treated with JMR-132, docetaxel or in combination. For studies in vivo, a subcutaneous nude mouse xenograft model was used. JMR-132 was administered s.c. at a dose of 10 µg/day and docetaxel at a dose of 10 mg/kg i.p. given on day 1 and 5. Similar regimens were used for the combination of both substances. At the end of the experiment, an mRNA-based human cancer pathway array including 84 major genes was performed on the tumor tissue of mice treated with JMR-132 to elucidate the mechanism of action of GHRH antagonists in vivo. The in vitro proliferation studies revealed that JMR-132 and docetaxel decreased the cell viability in a dose-dependent manner. The combination of both treatments produced a significantly greater inhibition of cell viability compared to the single agents. Treatment of nude mice bearing MDA-MB-231 xenografts with JMR-132 and docetaxel significantly (p<0.05) inhibited tumor growth by 46 and 50%, respectively. Treatment with the combination of JMR-132 and docetaxel led to an inhibition of tumor volume by 71.6% (p<0.001). Polymerase chain reaction array analysis revealed that JMR-132 interacts with signal transduction pathways involved in proliferation, apoptosis and angiogenesis. Our results suggest that GHRH antagonists in combination with taxanes may enhance the efficacy of treatment for patients with TNBC expressing the SV1 and/or the pGHRH receptor.

An update on the use of degarelix in the treatment of advanced hormone-dependent prostate cancer

Androgen deprivation therapy remains the mainstay of medical treatment for advanced prostate cancer. Commonly, this is achieved with medical androgen deprivation rather than surgical intervention as the permanence and psychological effects of the latter are unacceptable for most patients. Degarelix is a third generation antagonist of luteinizing hormone-releasing hormone (LHRH, also termed gonadotropin-releasing hormone) for the first-line treatment of androgen-dependent advanced prostate cancer. Degarelix acts directly on the pituitary receptors for LHRH, blocking the action of endogenous LHRH. The use of degarelix eliminates the initial undesirable surge in gonadotropin and testosterone levels, which is produced by agonists of LHRH. Degarelix is the most comprehensively studied and widely available LHRH antagonist worldwide. Clinical trials have demonstrated that degarelix has a long-term efficacy similar to the LHRH agonist leuprolide in achieving testosterone suppression in patients with prostate cancer. Degarelix, however, produces a faster suppression of testosterone and prostate-specific antigen (PSA), with no testosterone surges or microsurges, and thus prevents the risk of clinical flare in advanced disease. Recent clinical trials demonstrated that treatment with degarelix results in improved disease control when compared with an LHRH agonist in terms of superior PSA progression-free survival, suggesting that degarelix likely delays progression to castration-resistant disease and has a more significant impact on bone serum alkaline phosphatase and follicle-stimulating hormone. Degarelix is usually well tolerated, with limited toxicity and no evidence of systemic allergic reactions in clinical studies. Degarelix thus represents an important addition to the hormonal armamentarium for therapy of advanced androgen-dependent prostate cancer.

Shrinkage of experimental benign prostatic hyperplasia and reduction of prostatic cell volume by a gastrin-releasing peptide antagonist

Gastrin releasing-peptide (GRP) is a potent growth factor in many malignancies. Benign prostatic hyperplasia (BPH) is a progressive age-related proliferation of glandular and stromal tissues; various growth factors and inflammatory processes are involved in its pathogenesis. We have demonstrated that potent antagonists of GRP inhibit growth of experimental human tumors including prostate cancer, but their effect on models of BPH has not been studied. Here, we evaluated the effects of GRP antagonist RC-3940-II on viability and cell volume of BPH-1 human prostate epithelial cells and WPMY-1 prostate stromal cells in vitro, and in testosterone-induced BPH in Wistar rats in vivo. RC-3940-II inhibited the proliferation of BPH-1 and WPMY-1 cells in a dose-dependent manner and reduced prostatic cell volume in vitro. Shrinkage of prostates was observed after 6 wk of treatment with RC-3940-II: a 15.9% decline with 25 μg/d; and a 18.4% reduction with 50 μg/d (P < 0.05 for all). Significant reduction in levels of proliferating cell nuclear antigen, NF-κβ/p50, cyclooxygenase-2, and androgen receptor was also seen. Analysis of transcript levels of genes related to growth, inflammatory processes, and signal transduction showed significant changes in the expression of more than 90 genes (P < 0.05). In conclusion, GRP antagonists reduce volume of human prostatic cells and lower prostate weight in experimental BPH through direct inhibitory effects on prostatic GRP receptors. GRP antagonists should be considered for further development as therapy for BPH.