Ezetimibe Reduces Enlarged Prostate in an Animal Model of Benign Prostatic Hyperplasia

Ezetimibe and Cancer: Is There a Connection?

The high level of serum cholesterol caused by the excessive absorption of cholesterol can lead to hypercholesteremia, thus promoting the occurrence and development of cancer. Ezetimibe is a drug that reduces cholesterol absorption and has been widely used for the treatment of patients with high circulating cholesterol levels for many years. Mechanistically, ezetimibe works by binding to NPC1L1, which is a key mediator of cholesterol absorption. Accumulating data from preclinical models have shown that ezetimibe alone could inhibit the development and progression of cancer through a variety of mechanisms, including anti-angiogenesis, stem cell suppression, anti-inflammation, immune enhancement and anti-proliferation. In the past decade, there has been heated discussion on whether ezetimibe combined with statins will increase the risk of cancer. At present, more and more evidence shows that ezetimibe does not increase the risk of cancers, which supports the role of ezetimibe in anti-cancer. In this review, we discussed the latest progress in the anti-cancer properties of ezetimibe and elucidated its underlying molecular mechanisms. Finally, we highlighted the potential of ezetimibe as a therapeutic agent in future cancer treatment and prevention.

High degree of prostate related LUTS in a prospective cross-sectional community study in Ghana (Mamprobi)

Background

Changing voiding patterns, volume and frequency, may sometimes be mistaken for anxiety, stress or increase in fluid consumption. In the aging male population, the commencement of lower urinary tract symptoms (LUTS) may be silent and perceived as “normal” and unrelated to Benign prostatic enlargement (BPE). The purpose of the study was to determine the prevalence of apparently “silent LUTS” (perceived asymptomatic LUTS) in men in a Ghanaian Community as well as its underlying risk factors.

Methods

One hundred and eleven (111) men (40–70 years) were recruited from a community in Ghana. The International Prostate Symptoms Score (IPSS) questionnaire (administered in the local language and English) and ultrasonographic imaging of the prostate volume (PV) were utlized to collect data. IPSS score >7 plus PV > 30 cm³ was definitive of lower urinary tract symptoms. Eighty-one (81) participants were classified “LUTS Negative” (LN) and 30, “LUTS Positive” (LP). Risk factors i.e., cholesterol (CHOL), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), very low-density lipoprotein (VLDL), coronary risk (CR), BMI and Blood Pressure were also determined.

Results

The prevalence of LUTS using only IPSS definition alone was 42.3%. However, IPSS in combination with Prostate Volume gave a prevalence of 27.0%. LN subjects had enlarged prostate (41.98%) and LP, 100%. Quality of life (QoL) was better in the LUTS Negative than LUTS Positive group (p < 0.001). In the univariant analysis coronary risk, triglyceride and VLDL contributed to LUTS (p = 0.023, 0.22, 0.22, respectively). In a multivariant analysis HDL-C (p = 0.027), BMI (p = 0.047) and triglyceride (p = 0.019) significantly contributed to LUTS.

Conclusions

The prevalence of LUTS (42.3%) is high. Components of Metabolic Syndrome- HDL-C, BMI, and coronary risk were associated with LUTS. This emphasizes the need for community education.

Serum testosterone and prostate-specific antigen levels are major risk factors for prostatic volume increase among benign prostatic hyperplasia patients

Objective

Benign prostatic hyperplasia (BPH) is one of the most common diseases found among elderly men. Even though multiple risk factors of BPH have been identified in the past, the risk factors which have a direct impact on prostate volume have not been identified. In this study, we aim to determine the most significant contributing risk factors to prostate volume enlargement by analyzing possible associated risk factors previously studied.

Methods

This is a quantitative study with an analytical observational design, performed using a retrospective cohort approach. Total sampling was performed on 83 patients who underwent transurethral resection of the prostate (TURP) in Sanglah General Hospital from January to February 2019. Bivariate analysis is performed to examine each variable's association with prostate volume followed by a multivariate analysis. All variables were reassessed with path analysis to measure the direct effects, indirect effects, and total effects on prostate volume.

Results

Bivariate analysis shows that serum testosterone (R=0.208; p=0.059) and prostate-specific antigen (PSA) level (R=0.626; p=0.001) have a significant association with prostate volume. Multivariate analysis shows that serum PSA (B=1.4; p=0.001; 95% confidence interval [95% CI]=1.039–1.770) and testosterone (B=0.024; p=0.005; 95% CI=0.008–0.041) levels are significant among all the analyzed risk factors. There is a significant and strong effect of PSA to prostate volume (c=0.636; p=0.001) whereas testosterone has a significant albeit weak effect to prostate volume (c=0.246; p=0.009) based on the total effect of the path analysis.

Conclusion

Serum testosterone and PSA levels are significantly associated with prostatic volume increase among BPH patients.

Serum cholesterol and risk of lower urinary tract symptoms progression: Results from the Reduction by Dutasteride of Prostate Cancer Events study

OBJECTIVE

To determine if cholesterol is a risk factor for the development of lower urinary tract symptoms in asymptomatic men.

METHODS

A post-hoc analysis of the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) study was carried out in 2323 men with baseline International Prostate Symptom Score <8 and not taking benign prostatic hyperplasia or cholesterol medications. Cox proportion models were used to test the association between cholesterol, high-density lipoprotein, low-density lipoprotein and the cholesterol : high-density lipoprotein ratio with incident lower urinary tract symptoms, defined as first report of medical treatment, surgery or two reports of an International Prostate Symptom Score >14.

RESULTS

A total of 253 men (10.9%) developed incident lower urinary tract symptoms. On crude analysis, higher high-density lipoprotein was associated with a decreased lower urinary tract symptoms risk (hazard ratio 0.89, P = 0.024), whereas total cholesterol and low-density lipoprotein showed no association. After multivariable adjustment, the association between high-density lipoprotein and incident lower urinary tract symptoms remained significant (hazard ratio 0.89, P = 0.044), whereas no association was observed for low-density lipoprotein (P = 0.611). There was a trend for higher cholesterol to be linked with higher lower urinary tract symptoms risk, though this was not statistically significant (hazard ratio 1.04, P = 0.054). A higher cholesterol : high-density lipoprotein ratio was associated with increased lower urinary tract symptoms risk on crude (hazard ratio 1.11, P = 0.016) and adjusted models (hazard ratio 1.12, P = 0.012).

CONCLUSIONS

Among asymptomatic men participating in the REDUCE study, higher cholesterol was associated with increased incident lower urinary tract symptoms risk, though the association was not significant. A higher cholesterol : high-density lipoprotein ratio was associated with increased incident lower urinary tract symptoms, whereas higher high-density lipoprotein was protective. These findings suggest dyslipidemia might play a role in lower urinary tract symptoms progression.

Metabolic syndrome and benign prostatic enlargement: a systematic review and meta-analysis

OBJECTIVE

To summarise and meta-analyse current literature on metabolic syndrome (MetS) and benign prostatic enlargement (BPE), focusing on all the components of MetS and their relationship with prostate volume, transitional zone volume, prostate-specific antigen and urinary symptoms, as evidence suggests an association between MetS and lower urinary tract symptoms (LUTS) due to BPE.

METHODS

An extensive PubMed and Scopus search was performed including the following keywords: 'metabolic syndrome', 'diabetes', 'hypertension', 'obesity' and 'dyslipidaemia' combined with 'lower urinary tract symptoms', 'benign prostatic enlargement', 'benign prostatic hyperplasia' and 'prostate'.

RESULTS

Of the retrieved articles, 82 were selected for detailed evaluation, and eight were included in this review. The eight studies enrolled 5403 patients, of which 1426 (26.4%) had MetS defined according to current classification. Patients with MetS had significantly higher total prostate volume when compared with those without MetS (+1.8 mL, 95% confidence interval [CI] 0.74-2.87; P < 0.001). Conversely, there were no differences between patients with or without MetS for International Prostate Symptom Score total or LUTS subdomain scores. Meta-regression analysis showed that differences in total prostate volume were significantly higher in older (adjusted r = 0.09; P = 0.02), obese patients (adjusted r = 0.26; P < 0.005) and low serum high-density lipoprotein cholesterol concentrations (adjusted r = -0.33; P < 0.001).

CONCLUSIONS

Our results underline the exacerbating role of MetS-induced metabolic derangements in the development of BPE. Obese, dyslipidaemic, and aged men have a higher risk of having MetS as a determinant of their prostate enlargement.

Effect of pulsed electromagnetic field therapy on prostate volume and vascularity in the treatment of benign prostatic hyperplasia: a pilot study in a canine model

BACKGROUND

Benign prostatic hyperplasia (BPH) is a result of urogenital aging. Recent studies suggest that an age-related impairment of the blood supply to the lower urinary tract plays a role in the development of BPH and thus may be a contributing factor in the pathogenesis of BPH. The canine prostate is a model for understanding abnormal growth of the human prostate gland. We studied the efficacy of pulsed electromagnetic field therapy (PEMF) in dogs to modify prostate blood flow and evaluated its effect on BPH.

METHODS

PEMF (5 min, twice a day for 3 weeks) was performed on 20 dogs affected by BPH. Prostatic volume, Doppler assessment by ultrasonography, libido, semen quality, testosterone levels, and seminal plasma volume, composition and pH were evaluated before and after treatment.

RESULTS

The 3 weeks of PEMF produced a significant reduction in prostatic volume (average 57%) without any interference with semen quality, testosterone levels or libido. Doppler parameters showed a reduction of peripheral resistances and a progressive reduction throughout the trial of the systolic peak velocity, end-diastolic velocity, mean velocity, mean, and peak gradient of the blood flow in the dorsal branch of the prostatic artery. The pulsatility index and the resistance index did not vary significantly over time.

CONCLUSIONS

The efficacy of PEMF on BPH in dogs, with no side effects, suggests the suitability of this treatment in humans and supports the hypothesis that impairment of blood supply to the lower urinary tract may be a causative factor in the development of BPH.

PDE5 inhibitors blunt inflammation in human BPH: a potential mechanism of action for PDE5 inhibitors in LUTS

BACKGROUND

Metabolic syndrome (MetS) and benign prostate hyperplasia (BPH)/low urinary tract symptoms (LUTS) are often comorbid. Chronic inflammation is one of the putative links between these diseases. Phosphodiesterase type 5 inhibitors (PDE5i) are recognized as an effective treatment of BPH-related LUTS. One proposed mechanism of action of PDE5 is the inhibition of intraprostatic inflammation. In this study we investigate whether PDE5i could blunt inflammation in the human prostate.

METHODS

Evaluation of the effect of tadalafil and vardenafil on secretion of interleukin 8 (IL-8, a surrogate marker of prostate inflammation) by human myofibroblast prostatic cells (hBPH) exposed to different inflammatory stimuli. We preliminary evaluate histological features of prostatic inflammatory infiltrates in BPH patients enrolled in a randomized, double bind, placebo controlled study aimed at investigating the efficacy of vardenafil (10 mg/day, for 12 weeks) on BPH/LUTS.

RESULTS

In vitro treatment with tadalafil or vardenafil on hBPH reduced IL-8 secretion induced by either TNFα or metabolic factors, including oxidized low-density lipoprotein, oxLDL, to the same extent as a PDE5-insensitive PKG agonist Sp-8-Br-PET-cGMP. These effects were reverted by the PKG inhibitor KT5823, suggesting a cGMP/PKG-dependency. Treatment with tadalafil or vardenafil significantly suppressed oxLDL receptor (LOX-1) expression. Histological evaluation of anti-CD45 staining (CD45 score) in prostatectomy specimens of BPH patients showed a positive association with MetS severity. Reduced HDL-cholesterol and elevated triglycerides were the only MetS factors significantly associated with CD45 score. In the MetS cohort there was a significant lower CD45 score in the vardenafil-arm versus the placebo-one.

The response of the prostate to circulating cholesterol: activating transcription factor 3 (ATF3) as a prominent node in a cholesterol-sensing network

Elevated circulating cholesterol is a systemic risk factor for cardiovascular disease and metabolic syndrome, however the manner in which the normal prostate responds to variations in cholesterol levels is poorly understood. In this study we addressed the molecular and cellular effects of elevated and suppressed levels of circulating cholesterol on the normal prostate. Integrated bioinformatic analysis was performed using DNA microarray data from two experimental formats: (1) ventral prostate from male mice with chronically elevated circulating cholesterol and (2) human prostate cells exposed acutely to cholesterol depletion. A cholesterol-sensitive gene expression network was constructed from these data and the transcription factor ATF3 was identified as a prominent node in the network. Validation experiments confirmed that elevated cholesterol reduced ATF3 expression and enhanced proliferation of prostate cells, while cholesterol depletion increased ATF3 levels and inhibited proliferation. Cholesterol reduction in vivo alleviated dense lymphomononuclear infiltrates in the periprostatic adipose tissue, which were closely associated with nerve tracts and blood vessels. These findings open new perspectives on the role of cholesterol in prostate health, and provide a novel role for ATF3, and associated proteins within a large signaling network, as a cholesterol-sensing mechanism.

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.

Cholesterol and benign prostate disease

The origins of benign prostatic diseases, such as benign prostatic hyperplasia (BPH) and chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), are poorly understood. Patients suffering from benign prostatic symptoms report a substantially reduced quality of life, and the relationship between benign prostate conditions and prostate cancer is uncertain. Epidemiologic data for BPH and CP/CPPS are limited, however an apparent association between BPH symptoms and cardiovascular disease (CVD) has been consistently reported. The prostate synthesizes and stores large amounts of cholesterol and prostate tissues may be particularly sensitive to perturbations in cholesterol metabolism. Hypercholesterolemia, a major risk factor for CVD, is also a risk factor for BPH. Animal model and clinical trial findings suggest that agents that inhibit cholesterol absorption from the intestine, such as the class of compounds known as polyene macrolides, can reduce prostate gland size and improve lower urinary tract symptoms (LUTS). Observational studies indicate that cholesterol-lowering drugs reduce the risk of aggressive prostate cancer, while prostate cancer cell growth and survival pathways depend in part on cholesterol-sensitive biochemical mechanisms. Here we review the evidence that cholesterol metabolism plays a role in the incidence of benign prostate disease and we highlight possible therapeutic approaches based on this concept.

Relative influence of testosterone and insulin in the regulation of prostatic cell proliferation and growth

Prostatic hyperplasia is a common problem of the aged men population. Recent experimental and clinical studies provide sufficient evidence that apart from androgens, insulin also plays an important role in the pathogenesis of prostatic hyperplasia. The present study was aimed to investigate the relative influence of testosterone and insulin on the cellular proliferation and prostatic growth. Effect of testosterone on the prostate of hypoinsulinemic, and glandular injection of insulin-receptor antagonist S961 on the prostate of castrated Sprague-Dawley rat (220±10 g) was examined. Significant decrease in the weight of the ventral prostate was observed in the streptozotocin-induced hypoinsulinemic rats (~6 fold), which is restored by the intervention of testosterone. Although, glandular injection of S961 did not led to any change in the frequency of proliferating cell nuclear antigen (PCNA) positive cells in normal rats, significant decrease was observed in the castrated rats. Castration led to increase in the frequency of the caspase-3 and the TUNEL positive cells in the ventral prostate. Further, long-term (6 weeks) administration of S961 induced significant decrease in the weight of the ventral prostate. Results of the present study provide that both testosterone and insulin promote prostatic cell proliferation and change in the level of either of the hormone results in the destabilization of cellular equilibrium, and modulation of the insulin-receptor signaling in the prostate may provide an alternative strategy for the treatment of prostatic enlargement. Further, studies are required to better understand the interplay between these hormones in the regulation of prostatic growth.