Age-related changes in the innervation of the prostate gland: implications for prostate cancer initiation and progression

Ejaculation Frequency and Prostate Cancer Risk: A Narrative Review of Current Evidence

Prostate cancer, constituting a substantial portion of global cancer incidence and mortality, prompts a critical examination of potential modifiers, notably ejaculation frequency. This narrative review explores the complex relationship between ejaculation frequency and prostate cancer risk, addressing the paucity of consensus and the intricate interplay of factors. The evidence drawn from eleven studies with diverse methodologies reveals a complex understanding of this association. While some studies suggest an inverse correlation between ejaculation frequency and prostate cancer risk, signifying a potential protective effect, others present conflicting findings, necessitating a comprehensive exploration. Evidence synthesis underscores the importance of considering age, urinary health, and lifestyle factors in elucidating the ejaculation frequency-prostate cancer relationship. Notably, technological advancements, including machine learning models and genetic markers, enhance the precision of patient counselling and individualized care. In a clinical context, the findings emphasize the clinical relevance of incorporating sexual behavior into preventive strategies. Public health campaigns emerge as influential tools, breaking taboos, raising awareness, and empowering men to prioritize their well-being. The paradigm shift in prostate cancer understanding, fueled by technology and personalized medicine, holds promise for more accurate risk assessments. Liquid biopsies, multiparametric MRI, and considerations of the gut microbiome present avenues for tailored preventive strategies. However, methodological challenges and study variations necessitate further research, emphasizing consistency, exploring underlying mechanisms, and a life course perspective.

Diagnostic efficacy of systemic immune-inflammation biomarkers in benign prostatic hyperplasia using receiver operating characteristic and artificial neural network

Benign prostatic hyperplasia (BPH) is a chronic, progressive disease characterized by mesenchymal cell-predominance and stromal and glandular cell-hyperproliferation. Although, the precise cause of BPH is unknown, it is believed to be associated with hormonal changes in aging men. Despite androgens and ageing are likely to play a role in the development of BPH, the pathophysiology of BPH remains uncertain. This paper aims to evaluate the diagnostic efficacy of platelet-to-lymphocyte ratio (PLR), neutrophil-lymphocyte ratio (NLR) and systemic immune-inflammation index in in diagnosing BPH. A single-center-randomized-retrospective study was carried out at Alzahraa university hospital between January 2022 and November 2022 on 80 participants (40 non-BPH subjects and 40 patients with symptomatic enlarged prostate) who visited the outpatient clinic or admitted to the urology department. The BPH cases were evaluated by digital rectal examination (DRE), International Prostate Symptom Score (IPSS), prostate size, prostate specific antigen (PSA), TRUS biopsy in elevated PSA > 4 ng/ml, PLR, NLR and systemic immune inflammatory (SII). The diagnosing efficiency of the selected parameters was evaluated using Receiver Operating Characteristic (ROC) and Artificial Neural Network (ANN) showing excellent discrimination with 100% accuracy and AUC = 1 in the ROC curves. Moreover, the accuracy rate of the ANN exceeds 99%. Conclusion: PLR, NLR and SII can be significantly employed for diagnosing BPH.

The nerve growth factor-delivered signals in prostate cancer and its associated microenvironment: when the dialogue replaces the monologue

Prostate cancer (PC) represents the most diagnosed and the second most lethal cancer in men worldwide. Its development and progression occur in concert with alterations in the surrounding tumor microenvironment (TME), made up of stromal cells and extracellular matrix (ECM) that dynamically interact with epithelial PC cells affecting their growth and invasiveness. PC cells, in turn, can functionally sculpt the TME through the secretion of various factors, including neurotrophins. Among them, the nerve growth factor (NGF) that is released by both epithelial PC cells and carcinoma-associated fibroblasts (CAFs) triggers the activation of various intracellular signaling cascades, thereby promoting the acquisition of a metastatic phenotype. After many years of investigation, it is indeed well established that aberrations and/or derangement of NGF signaling are involved not only in neurological disorders, but also in the pathogenesis of human proliferative diseases, including PC. Another key feature of cancer progression is the nerve outgrowth in TME and the concept of nerve dependence related to perineural invasion is currently emerging. NGF released by cancer cells can be a driver of tumor neurogenesis and nerves infiltrated in TME release neurotransmitters, which might stimulate the growth and sustainment of tumor cells.In this review, we aim to provide a snapshot of NGF action in the interactions between TME, nerves and PC cells. Understanding the molecular basis of this dialogue might expand the arsenal of therapeutic strategies against this widespread disease.

Understanding and modeling nerve-cancer interactions

The peripheral nervous system plays an important role in cancer progression. Studies in multiple cancer types have shown that higher intratumoral nerve density is associated with poor outcomes. Peripheral nerves have been shown to directly regulate tumor cell properties, such as growth and metastasis, as well as affect the local environment by modulating angiogenesis and the immune system. In this Review, we discuss the identity of nerves in organs in the periphery where solid tumors grow, the known mechanisms by which nerve density increases in tumors, and the effects these nerves have on cancer progression. We also discuss the strengths and weaknesses of current in vitro and in vivo models used to study nerve-cancer interactions. Increased understanding of the mechanisms by which nerves impact tumor progression and the development of new approaches to study nerve-cancer interactions will facilitate the discovery of novel treatment strategies to treat cancer by targeting nerves.

Head-up tilt does not enhance prostate tumor perfusion or oxygenation in young rats

Solid tumors contain hypoxic regions that contribute to anticancer therapy resistance. Thus, mitigating tumor hypoxia may enhance the efficacy of radiation therapy which is commonly utilized for patients with prostate cancer. Increasing perfusion pressure in the prostate with head-up tilt (HUT) may augment prostate tumor perfusion and decrease hypoxia. The purpose of this study was to determine if an increase in the vascular hydrostatic gradient via 70° HUT increases tumor perfusion and decreases tumor hypoxia in a preclinical orthotopic model of prostate cancer. Male Copenhagen rats (n = 17) were orthotopically injected with Dunning R-3327 (AT-1) prostate adenocarcinoma cells to induce prostate tumors. After tumors were established, prostate tumor perfusion and hypoxia were measured in rats during level (0°) and 70° HUT positions. To compare the magnitude of the hydrostatic column to that present in humans, ultrasound was used to measure the heart to prostate distance in male human subjects to estimate the prostate vascular hydrostatic pressure with the upright posture. In young rats, no differences were detected in prostate tumor perfusion or prostate tumor hypoxia with 70° HUT versus the level position. However, from the retrospective study, young rats increased prostate vascular resistance to HUT, whereas aged rats lacked this response. Tumor vessels co-opted from existing functional vasculature in young rats may be sufficient to negate increases in perfusion pressure with HUT seen in aged rats. Additionally, in humans, the estimated hydrostatic column at the level of the prostate is five times greater than that of the rat. Therefore, 70° HUT may elicit increases in prostate/prostate tumor blood flow in humans that is not seen in rats.

Stem Cell-Based Models for Studying the Effects of Cancer and Cancer Therapies on the Peripheral Nervous System

In recent years, the complexity of cancer and cancer therapies and their interactions with the peripheral nervous system have come into focus, but limitations in experimental models have remained a significant challenge in the field. As evidence, there are currently no therapies approved that target cancer-peripheral nervous system or cancer therapy-peripheral nervous system interactions as an anti-neoplastic or anti-neurotoxic agent, respectively. Human pluripotent stem cells offer an appealing model system that, unlike rodent models, is compatible with high throughput, high content applications; techniques that reflect modern drug discovery methodologies. Thus, utilizing the key advantages of stem cell-based models in tandem with the strengths of traditional animal models offers a complementary and interdisciplinary strategy to advance cancer and cancer therapy-peripheral nervous system research and drug discovery. In this review, the current status of the cancer-peripheral nervous system and cancer therapy-peripheral nervous system research is discussed, examples where stem cell-based models have been implemented are described, and avenues where stem cell-based models may further advance the field are proposed.

Psychosocial Stress and Age Influence Depression and Anxiety-Related Behavior, Drive Tumor Inflammatory Cytokines and Accelerate Prostate Cancer Growth in Mice

Prostate cancer (PCa) prevalence is higher in older men and poorer coping with psychosocial stressors effect prognosis. Yet, interactions between age, stress and PCa progression are underexplored. Therefore, we characterized the effects of age and isolation combined with restraint (2 h/day) for 14 days post-tumor inoculation on behavior, tumor growth and host defense in the immunocompetent, orthotopic RM-9 murine PCa model. All mice were tumor inoculated. Isolation/restraint increased sympathetic and hypothalamic-pituitary-adrenal cortical activation, based on elevated serum 3-methoxy-4-hydroxyphenylglycol/norepinephrine ratios and corticosterone levels, respectively. Elevated zero maze testing revealed age-related differences in naïve C57Bl/6 mice, and increased anxiety-like behavior in tumor-bearing mice. In open field testing, old stressed mice were less active throughout the 30-min test than young non-stressed and stressed, and old non-stressed mice, suggesting greater anxiety in old stressed mice. Old (18 month) mice demonstrated more depression-like behavior than young mice with tail suspension testing, without effects of isolation/restraint stress. Old mice developed larger tumors, despite similar tumor expression of tumor vascular endothelial growth factor or transforming growth factor-beta1 across age. Tumor chemokine/cytokine expression, commonly prognostic for poorer outcomes, were uniquely age- and stress-dependent, underscoring the need for PCa research in old animals. Macrophages predominated in RM-9 tumors. Macrophages, and CD4⁺ and CD4⁺FoxP3⁺ T-cell tumor infiltration were greater in young mice than in old mice. Stress increased macrophage infiltration in old mice. Conversely, stress reduced intratumoral CD4⁺ and CD4⁺FoxP3⁺ T-cell numbers in young mice. CD8⁺ T-cell infiltration was similar across treatment groups. Our findings support that age- and psychological stress interacts to affect PCa outcomes by interfering with neural-immune mechanisms and affecting behavioral responses.

The Etiology and Pathophysiology Genesis of Benign Prostatic Hyperplasia and Prostate Cancer: A New Perspective

Background: The etiology of benign prostatic hyperplasia and prostate cancer are unknown, with ageing being the greatness risk factor. Methods: This new perspective evaluates the available interdisciplinary evidence regarding prostate ageing in terms of the cell biology of regulation and homeostasis, which could explain the timeline of evolutionary cancer biology as degenerative, inflammatory and neoplasm progressions in these multifactorial and heterogeneous prostatic diseases. Results: This prostate ageing degeneration hypothesis encompasses the testosterone-vascular-inflamm-ageing triad, along with the cell biology regulation of amyloidosis and autophagy within an evolutionary tumorigenesis microenvironment. Conclusions: An understanding of these biological processes of prostate ageing can provide potential strategies for early prevention and could contribute to maintaining quality of life for the ageing individual along with substantial medical cost savings.

Nonscrotal Causes of Acute Scrotum

Acute scrotum is characterized by intense acute scrotal pain, which may be associated with other symptoms and signs such as abdominal pain, inflammation, and fever. Many pathologic conditions can present in this way, most which involve the scrotal contents. Nonscrotal conditions, however, can rarely present clinically only as acute scrotum: among them, renal colic, aneurysm rupture or other causes of retroperitoneal hemorrhage, primary abdominal or pelvic tumors and metastases, pancreatitis, pelvic inflammation, and muscle injuries. The pathophysiologic characteristics of the clinical presentation, clues for diagnosis, and imaging features of a series of nonscrotal lesions presenting clinically with acute scrotal pain are herein reported and illustrated. In patients presenting with acute scrotal symptoms and normal scrotal ultrasound findings, nonscrotal causes of acute scrotal pain should be considered in the differential diagnosis. Therefore, an ultrasound investigation of the abdomen, groin, and thighs is indicated.

Nerve input to tumours: Pathophysiological consequences of a dynamic relationship

It is well known that tumours arising in different organs are innervated and that 'perineural invasion' (cancer cells escaping from the tumour by following the nerve trunk) is a negative prognostic factor. More surprisingly, increasing evidence suggests that the nerves can provide active inputs to tumours and there is two-way communication between nerves and cancer cells within the tumour microenvironment. Cells of the immune system also interact with the nerves and cancer cells. Thus, the nerve connections can exert significant control over cancer progression and modulating these (physically or chemically) can affect significantly the cancer process. Nerve inputs to tumours are derived mainly from the sympathetic (adrenergic) and the parasympathetic (cholinergic) systems, which are interactive. An important component of the latter is the vagus nerve, the largest of the cranial nerves. Here, we present a two-part review of the nerve inputs to tumours and their effects on tumorigenesis. First, we review briefly some relevant general issues including ultrastructural aspects, stemness, interactions between neurones and primary tumours, and communication between neurones and metastasizing tumour cells. Ultrastructural characteristics include synaptic vesicles, tumour microtubes and gap junctions enabling formation of cellular networks. Second, we evaluate the pathophysiology of the nerve input to five major carcinomas: cancers of prostate, stomach, colon, lung and pancreas. For each cancer, we present (i) the nerve inputs normally present in the cancer organ and (ii) how these interact and influence the cancer process. The best clinical evidence for the role of nerves in promoting tumorigenesis comes from prostate cancer patients where metastatic progression has been shown to be suppressed significantly in cases of spinal cord injury. The balance of the sympathetic and parasympathetic contributions to early versus late tumorigenesis varies amongst the different cancers. Different branches of the vagus provide functional inputs to several of the carcinomas and, in two-way interaction with the sympathetic nervous system, affect different stages of the cancer process. Overall, the impact of the vagus nerve can be 'direct' or 'indirect'. Directly, the effect of the vagus is primarily to promote tumorigenesis and this is mediated through cholinergic receptor mechanisms. Indirectly, pro- and anti-tumour effects can occur by stimulation or inhibition of the sympathetic nervous system, respectively. Less well understood are the 'indirect' anti-tumour effect of the vagus nerve via immunomodulation/inflammation, and the role of sensory innervation. A frequent occurrence in the nerve-tumour interactions is the presence of positive feedback driven by agents like nerve growth factor. We conclude that the nerve inputs to tumours can actively and dynamically impact upon cancer progression and are open to clinical exploitation.

Immunoendocrine Markers of Stress in Seminal Plasma at IVF/ICSI Failure: a Preliminary Study

We have previously shown that high level of seminal interleukin (IL)-18 is positively associated with a greater risk of pregnancy failure in women exposed to their partners' seminal plasma (SP) during the in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycle. Since IL-18 and IL-1β considered to be the key immune markers of stress, here we ask whether their increase in SP may be due to the stress experienced by men engaged in the IVF programs. Therefore, we correlated seminal IL-18 with IL-1β and both cytokines with the seminal steroids, whose increase indicates the activation of neuroendocrine stress response systems. Retrospective analysis of stored seminal samples was performed. Based on previously identified cutoff level for content of IL-18 per ejaculate, samples with high IL-18 content from IVF failure group (n = 9), as well as samples with low IL-18 content from IVF success group (n = 7), were included in the study. Seminal cytokines were evaluated using FlowCytomix™ technology. A set of 16 biologically active steroids in SP was quantified by liquid chromatography coupled with mass spectrometry. Concentrations and total amounts per ejaculate of cytokines and steroids were determined. A positive significant correlation was found between the levels of IL-18 and IL-1β. There was also a positive correlation between IL-18 or IL-1β and 17-α-hydroxypregnenolone, 17-α-hydroxyprogesterone, dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), androstenedione, testosterone, dihydrotestosterone, progesterone, corticosterone, 11-deoxycorticosterone, and the ratio of DHEAS/cortisol. We suggested that stress-related overexpression of immune and hormonal factors in SP may be the key link between male stress and embryo implantation failure.

Inhibitory Effect of Artemisinin on Testosterone Propionate Induced Benign Prostatic Hyperplasia

BACKGROUND

Benign prostate hyperplasia [BPH] is an abnormal growth of prostate observed commonly in elderly males. Artemisinin has been reported to reduce the levels of testosterone.

OBJECTIVE

This study is designed to evaluate the efficacy of Artemisinin on testosterone propionate [TP] induced benign prostate hyperplasia.

MATERIALS AND METHODS

Male Wistar albino rats [n=24] were separated into four groups of six rats each. Group I served as control and distilled water using tween 80 as an emulsifying agent was administered subcutaneously. BPH was induced by testosterone propionate 3mg/kg [Group II], S.C. daily for 28 days. Group III was BPH + Finasteride treated group (10mg/kg orally for 28 days) and BPH + Artemisinin treated group (Group IV) (50 mg/kg orally for 28 days).

RESULT

The study results showed significantly high levels of serum prostatic acid phosphatase (PAP), lactate dehydrogenase (LDH) and an elevation in prostate weight and prostatic index in Group II (BPH) when compared with Group I. The histopathological examination showed an increase in the epithelial proliferation of prostatic cells with involutions protruding into the lumen in BPH group when compared to the normal group. Treatment with Artemisinin (50 mg/kg) reduced the levels of PAP, LDH, prostate weight and prostatic index to a significant extent and restored the histoarchitectural features of the cells.

CONCLUSION

The present study concludes that Artemisinin is efficacious in testosterone propionate induced BPH. This could be attributed, at least partly, to its anti-inflammatory property or its role in testosterone level reduction or as a Vitamin D receptor modulator.

In utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure exacerbates urinary dysfunction in hormone-treated C57BL/6J mice through a non-malignant mechanism involving proteomic changes in the prostate that differ from those elicited by testosterone and estradiol

A recent study directed new focus on the fetal and neonatal environment as a risk factor for urinary dysfunction in aging males. Male mice were exposed in utero and via lactation (IUL) to the persistent environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and then administered slow-release, subcutaneous implants of testosterone and estradiol (T+E2) as adults to mimic the hormonal environment of aging men. IUL TCDD exposure worsened T+E2-induced voiding dysfunction. Mice in the previous study were genetically prone to prostatic neoplasia and it was therefore unclear whether TCDD exacerbates voiding dysfunction through a malignant or non-malignant mechanism. We demonstrate here that IUL TCDD exposure acts via a non-malignant mechanism to exacerbate T+E2-mediated male mouse voiding dysfunction characterized by a progressive increase in spontaneous void spotting. We deployed a proteomic approach to narrow the possible mechanisms. We specifically tested whether IUL TCDD exacerbates urinary dysfunction by acting through the same prostatic signaling pathways as T+E2. The prostatic protein signature of TCDD/T+E2-exposed mice differed from that of mice exposed to T+E2 alone, indicating that the mechanism of action of TCDD differs from that of T+E2. We identified 3641 prostatic proteins in total and determined that IUL TCDD exposure significantly changed the abundance of 102 proteins linked to diverse molecular and physiological processes. We shed new light on the mechanism of IUL TCDD-mediated voiding dysfunction by demonstrating that the mechanism is independent of tumorigenesis and involves molecular pathways distinct from those affected by T+E2.

Mechanism of Action of Botulinum Toxin A in Treatment of Functional Urological Disorders

Intravesical botulinum toxin (BoNT) injection is effective in reducing urgency and urinary incontinence. It temporarily inhibits the detrusor muscle contraction by blocking the release of acetylcholine (Ach) from the preganglionic and postganglionic nerves in the efferent nerves. BoNT-A also blocks ATP release from purinergic efferent nerves in the detrusor muscle. In afferent nerves, BoNT-A injection markedly reduces the urothelial ATP release and increases nitric oxide (NO) release from the urothelium. BoNT-A injection in the urethra or bladder has been developed in the past few decades as the treatment method for detrusor sphincter dyssyndergia, incontinence due to neurogenic or idiopathic detrusor overactivity, sensory disorders, including bladder hypersensitivity, overactive bladder, and interstitial cystitis/chronic pelvic pain syndrome. Although the FDA only approved BoNT-A injection treatment for neurogenic detrusor overactivity and for refractory overactive bladder, emerging clinical trials have demonstrated the benefits of BoNT-A treatment in functional urological disorders. Cautious selection of patients and urodynamic evaluation for confirmation of diagnosis are crucial to maximize the successful outcomes of BoNT-A treatment.

Inhibitory effect of α1D/1A antagonist 2-(1H-indol-3-yl)-N-[3-(4-(2-methoxyphenyl) piperazinyl) propyl] acetamide on estrogen/androgen-induced rat benign prostatic hyperplasia model in vivo

Benign prostatic hyperplasia (BPH) is a common disorder of the urinary system in aging men. 2-(1H-indol-3-yl)-N-[3-(4-(2-methoxyphenyl) piperazinyl) propyl] acetamide (HJZ-3), which is derived from naftopidil, exhibited 97.7- and 64.6-fold greater inhibitory effects for a_1D adrenoceptor than for a_1B- and a_1A-adrenoceptors in vitro, respectively. To investigate the therapeutic potential for treating BPH, we evaluated the pharmacological activity of HJZ-3. Specifically, we evaluated through estrogen/androgen-induced rat benign prostatic hyperplasia model in vivo. HJZ-3 effectively prevented the progression of rat prostatic hyperplasia by suppressing the increase in prostate index and reducing the quantitative analysis of the relative acinus volume, relative stroma, epithelial volume and epithelial thickness and expression of proliferating cell nuclear antigen and α-smooth muscle actin. HJZ-3 decreased α_1A- and α_1D-adrenoceptor protein expressions in prostate tissue. HJZ-3 is a good alternative for α_1A- and α_1D-adrenoceptor blocker. It may relax smooth muscle tone and relieve symptoms of BPH.

Impact of biopsy perineural invasion on the outcomes of patients who underwent radical prostatectomy: a systematic review and meta-analysis

Objectives: To investigate the association between biopsy perineural invasion (PNI) and oncological outcomes of prostate cancer (PCa) after radical prostatectomy (RP).Materials and methods: A systematic literature search was performed using PubMed, EMBASE and Web of Science up to December 2018 to identify the eligible studies that included localized PCa patients who underwent biopsy and subsequently RP as well as follow-up information. Meta-analyses were conducted using available hazard ratios (HRs) of biopsy PNI from both univariate and multivariate analyses.Results: Eighteen studies including 14,855 patients with treatment follow-up information were included in the current systematic review. The rate of biopsy PNI varied between 7.0% and 33.0%. Seven out of the 18 studies that demonstrated biopsy PNI were associated with adverse pathologic features. Thirteen out of the 18 studies showed biopsy PNI correlated significantly with higher rates of biochemical recurrence (BCR)/cancer progression status or worse prognostic outcomes. With pooled data based on four studies with available univariate analysis results and four studies with multivariate analysis, statistically significant associations were found between biopsy PNI and BCR with univariate analysis (HR = 2.05; 95% CI = 1.57-2.68; p < 0.001) and with multivariate analysis (HR = 1.57; 95% CI = 1.28-1.93; p < 0.001).Conclusion: Evidence from the included observational studies indicated that biopsy PNI was not only correlated with adverse pathologic characteristics but also with worse BCR prognosis of local PCa after RP. The status of biopsy PNI could serve as a promising risk-stratification factor to help the decision-making process, considering active surveillance (AS) or further treatment for PCa patients.

Chronic prostatitis: current treatment options

Male chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is represented by a heterogeneous group of symptoms that can cause an important impairment of daily quality of life for patients. Diagnosis of CP/CPPS is often not clear and treatment can be challenging, as it varies according to the different causative factors and derived symptoms. Differently from approaches used in the past, the diagnosis and subsequent treatment rely on separating this entity from chronic bacterial prostatitis and considering it as a multifactorial disease. Autoimmunity and inflammation, myofascial tenderness, neuroinflammation, and psychological causes have been clearly related to this disease, and therefore CPPS should not only be considered as related to benign prostatic enlargement. A multitude of different symptoms related to urinary, genital, rectal, and perineal areas can be attributed to this condition and therefore should be routinely investigated in patients, as well as possible differential diagnoses which can cause the same symptoms, such as pudendal nerve entrapment syndrome. The aim of this narrative review is to focus on CPPS after an infectious cause has been excluded.

A temporal and spatial map of axons in developing mouse prostate

Prostate autonomic and sensory axons control glandular growth, fluid secretion, and smooth muscle contraction and are remodeled during cancer and inflammation. Morphogenetic signaling pathways reawakened during disease progression may drive this axon remodeling. These pathways are linked to proliferative activities in prostate cancer and benign prostate hyperplasia. However, little is known about which developmental signaling pathways guide axon investment into prostate. The first step in defining these pathways is pinpointing when axon subtypes first appear in prostate. We accomplished this by immunohistochemically mapping three axon subtypes (noradrenergic, cholinergic, and peptidergic) during fetal, neonatal, and adult stages of mouse prostate development. We devised a method for peri-prostatic axon density quantification and tested whether innervation is uniform across the proximo-distal axis of dorsal and ventral adult mouse prostate. Many axons directly interact with or innervate neuroendocrine cells in other organs, so we examined whether sensory or autonomic axons innervate neuroendocrine cells in prostate. We first detected noradrenergic, cholinergic, and peptidergic axons in prostate at embryonic day (E) 14.5. Noradrenergic and cholinergic axon densities are uniform across the proximal-distal axis of adult mouse prostate while peptidergic axons are denser in the periurethral and proximal regions. Peptidergic and cholinergic axons are closely associated with prostate neuroendocrine cells whereas noradrenergic axons are not. These results provide a foundation for understanding mouse prostatic axon development and organization and, provide strategies for quantifying axons during progression of prostate disease.

ADRB2-Targeting Therapies for Prostate Cancer

There is accumulating evidence that β-2 adrenergic receptor (ADRB2) signaling contributes to the progression and therapy resistance of prostate cancer, whereas availability of clinically tested β-blocker propranolol makes this pathway especially attractive as potential therapeutic target. Yet even in tumors with active ADRB2 signaling propranolol may be ineffective. Inhibition of apoptosis is one of the major mechanisms by which activation of ADRB2 contributes to prostate cancer pathophysiology. The signaling network that controls apoptosis in prostate tumors is highly redundant, with several signaling pathways targeting a few critical apoptosis regulatory molecules. Therefore, a comprehensive analysis of ADRB2 signaling in the context of other signaling mechanisms is necessary to identify patients who will benefit from propranolol therapy. This review discusses how information on the antiapoptotic mechanisms activated by ADRB2 can guide clinical trials of ADRB2 antagonist propranolol as potential life-extending therapy for prostate cancer. To select patients for clinical trials of propranolol three classes of biomarkers are proposed. First, biomarkers of ADRB2/cAMP-dependent protein kinase (PKA) pathway activation; second, biomarkers that inform about activation of other signaling pathways unrelated to ADRB2; third, apoptosis regulatory molecules controlled by ADRB2 signaling and other survival signaling pathways.

Impact of α-adrenoceptor antagonists on prostate cancer development, progression and prevention

Two decades following the discovery that α1-adrenoceptor antagonists suppress prostate tumor growth at the molecular and cellular level, the impact of α-blockade as re-purposed treatment strategy in the medical management of prostate cancer is gradually being recognized. Prostate cancer is the second most common cause of cancer deaths among males in the United States, yet the disease maintains inconsistent recommendations for prevention and screening. The functional relationship between α-adrenergic signaling and smooth muscle cells in the stroma of the prostate gland and the bladder neck empowered the use of α-adrenoceptor antagonists for the relief of urethral obstruction and clinical symptoms associated with benign prostatic hyperplasia (BPH). Adrenoceptors are G-protein-coupled receptors (GCPRs) that are functionally bound by catecholamines: epinephrine (ER) and norepinephrine (NE). The α1A adrenoceptor subtype is primarily responsible for smooth muscle contraction in the bladder neck and prostate gland. α1-adrenoceptor antagonists are clinically indicated as first-line therapies for the relief of BPH, hypertension, and post-traumatic stress disorder (PTSD). Compelling evidence from cellular and pre-clinical models have identified additional effects of α1-adrenoceptor antagonists regarding their ability to induce apoptosis-mediated suppression of prostate tumor growth and metastasis. Additionally, early epidemiologic data suggest that they may serve as a safe treatment to reduce the risk of prostate cancer. Optimization of quinazoline based compounds (doxazosin) to exploit pharmacologic targeting of tumor growth and vascularization revealed high efficacy of the lead novel compound DZ-50 against prostate tumors. This review discusses the experimental and pre-clinical evidence on the impact of α-blockade on prostate cancer.

Inhibition of Multidrug Resistance Proteins by MK 571 Enhances Bladder, Prostate, and Urethra Relaxation through cAMP or cGMP Accumulation

The biologic effect of cAMP and cGMP is terminated by phosphodiesterases and multidrug resistance proteins MRP4 and MRP5, which pump cyclic nucleotides out of the cell. Therefore, this study aimed to characterize the role of MRP inhibitor, MK 571 (3-[[[3-[(1E)-2-(7-chloro-2-quinolinyl)ethenyl]phenyl][[3-(dimethylamino)-3-oxopropyl]thio]methyl]thio]propanoic acid), in the bladder, prostate, and urethra of male mice by means of functional assays, protein expression, and cyclic nucleotide quantification. The cumulative addition of MK 571 (1-30 µM) produced only small relaxation responses (approximately 25%) in all studied tissues. In the bladder, isoprenaline/fenoterol and forskolin concentration-dependently relaxed and MK 571 (20 µM) increased the maximal response values by 37% and 24%, respectively. When MK 571 was coincubated with fenoterol or forskolin, intracellular levels of cAMP and protein expression of phospho-vasodilator-stimulated phosphoprotein (p-VASP) Ser157 were significantly greater compared with bladders stimulated with fenoterol or forskolin alone. In the prostate and urethra, sodium nitroprusside concentration-dependently relaxed and MK 571 (20 µM) significantly increased relaxation responses by 70% and 56%, respectively, accompanied by greater intracellular levels of cGMP and protein expression of p-VASP Ser239 in the prostate. Tadalafil and BAY 41-2272 (5-cyclopropyl-2-[1-[(2-fluorophenyl)methyl]-1H-pyrazolo[3,4-b]pyridin-3-yl]-4-pyrimidinamine) also relaxed the prostate and urethra, respectively, and MK 571 markedly enhanced this response. The stable analog of cGMP (8-Br-cGMP) induced concentration-dependent relaxation responses in the prostate and urethra, and MK 571 significantly increased the relaxation response. In conclusion, to our knowledge, this is the first study to show that efflux transporters are physiologically active in the bladder, prostate, and urethra to control intracellular levels of cAMP or cGMP.

Monoamine Oxidase Deficiency Causes Prostate Atrophy and Reduces Prostate Progenitor Cell Activity

Monoamine oxidases (MAOs) degrade a number of biogenic and dietary amines, including monoamine neurotransmitters, and play an essential role in many biological processes. Neurotransmitters and related neural events have been shown to participate in the development, differentiation, and maintenance of diverse tissues and organs by regulating the specialized cellular function and morphological structures of innervated organs such as the prostate. Here we show that mice lacking both MAO isoforms, MAOA and MAOB, exhibit smaller prostate mass and develop epithelial atrophy in the ventral and dorsolateral prostates. The cellular composition of prostate epithelium showed reduced CK5⁺ or p63⁺ basal cells, accompanied by lower Sca-1 expression in p63⁺ basal cells, but intact differentiated CK8⁺ luminal cells in MAOA/B-deficient mouse prostates. MAOA/B ablation also decreased epithelial cell proliferation without affecting cell apoptosis in mouse prostates. Using a human prostate epithelial cell line, we found that stable knockdown of MAOA and MAOB impaired the capacity of prostate stem cells to form spheres, coinciding with a reduced CD133⁺ /CD44⁺ /CD24^- stem cell population and less expression of CK5 and select stem cell markers, including ALDH1A1, TROP2, and CD166. Alternative pharmacological inhibition of MAOs also repressed prostate cell stemness. In addition, we found elevated expression of MAOA and MAOB in epithelial and/or stromal components of human prostate hyperplasia samples compared with normal prostate tissues. Taken together, our findings reveal critical roles for MAOs in the regulation of prostate basal progenitor cells and prostate maintenance. Stem Cells 2018;36:1249-1258.

The Role of α1-Adrenoceptor Antagonists in the Treatment of Prostate and Other Cancers

This review evaluates the role of α-adrenoceptor antagonists as a potential treatment of prostate cancer (PCa). Cochrane, Google Scholar and Pubmed were accessed to retrieve sixty-two articles for analysis. In vitro studies demonstrate that doxazosin, prazosin and terazosin (quinazoline α-antagonists) induce apoptosis, decrease cell growth, and proliferation in PC-3, LNCaP and DU-145 cell lines. Similarly, the piperazine based naftopidil induced cell cycle arrest and death in LNCaP-E9 cell lines. In contrast, sulphonamide based tamsulosin did not exhibit these effects. In vivo data was consistent with in vitro findings as the quinazoline based α-antagonists prevented angiogenesis and decreased tumour mass in mice models of PCa. Mechanistically the cytotoxic and antitumor effects of the α-antagonists appear largely independent of α 1-blockade. The proposed targets include: VEGF, EGFR, HER2/Neu, caspase 8/3, topoisomerase 1 and other mitochondrial apoptotic inducing factors. These cytotoxic effects could not be evaluated in human studies as prospective trial data is lacking. However, retrospective studies show a decreased incidence of PCa in males exposed to α-antagonists. As human data evaluating the use of α-antagonists as treatments are lacking; well designed, prospective clinical trials are needed to conclusively demonstrate the anticancer properties of quinazoline based α-antagonists in PCa and other cancers.

Blood flow responses to mild-intensity exercise in ectopic vs. orthotopic prostate tumors; dependence upon host tissue hemodynamics and vascular reactivity

Given the critical role of tumor O2 delivery in patient prognosis and the rise in preclinical exercise oncology studies, we investigated tumor and host tissue blood flow at rest and during exercise as well as vascular reactivity using a rat prostate cancer model grown in two transplantation sites. In male COP/CrCrl rats, blood flow (via radiolabeled microspheres) to prostate tumors [R3327-MatLyLu cells injected in the left flank (ectopic) or ventral prostate (orthotopic)] and host tissue was measured at rest and during a bout of mild-intensity exercise. α-Adrenergic vasoconstriction to norepinephrine (NE: 10(-9) to 10(-4) M) was determined in arterioles perforating the tumors and host tissue. To determine host tissue exercise hyperemia in healthy tissue, a sham-operated group was included. Blood flow was lower at rest and during exercise in ectopic tumors and host tissue (subcutaneous adipose) vs. the orthotopic tumor and host tissue (prostate). During exercise, blood flow to the ectopic tumor significantly decreased by 25 ± 5% (SE), whereas flow to the orthotopic tumor increased by 181 ± 30%. Maximal vasoconstriction to NE was not different between arterioles from either tumor location. However, there was a significantly higher peak vasoconstriction to NE in subcutaneous adipose arterioles (92 ± 7%) vs. prostate arterioles (55 ± 7%). Establishment of the tumor did not alter host tissue blood flow from either location at rest or during exercise. These data demonstrate that blood flow in tumors is dependent on host tissue hemodynamics and that the location of the tumor may critically affect how exercise impacts the tumor microenvironment and treatment outcomes.

The relationship between perineural invasion, tumor grade, reactive stroma and prostate cancer-specific mortality: A clinicopathologic study on a population-based cohort

BACKGROUND

In vitro and in vivo studies have shown that nerves, tumor epithelium, and stroma interact and promote prostate cancer (PC) progression. Perineural invasion (PNI) is established amidst these interactions and may therefore indicate an aggressive PC phenotype. The purpose of the present study was to determine the relationship between PNI, tumor grade, reactive stroma, and PC-specific mortality.

METHODS

A population-based study on 318 patients, encompassing all cases of PC diagnosed by needle biopsies and without evidence of systemic metastasis at the time of diagnosis in Aust-Agder County in the period of 1991-1999. Patients were identified by cross-referencing the Cancer Registry of Norway. Clinical data were obtained by review of medical charts. Diagnostic prostate needle biopsies were reviewed with respect to presence of PNI, percentage of biopsy cores with PNI, Gleason score (GS), and reactive stromal grade (RSG). The endpoint was PC-specific mortality.

RESULTS

The presence of PNI was significantly associated with high tumor grade and abundant reactive stroma. The 10-year PC-specific survival for patients with and without PNI was 72% and 91%, respectively (P = 0.001, log rank). PNI predicted PC-specific mortality independently of clinical factors, though the effect of PNI was attenuated when adjusting for GS and RSG. However, a percentage of biopsy cores with PNI >50% was found to predict PC-specific mortality independently of other clinicopathologic parameters.

CONCLUSIONS

The present population-based study shows that PNI on diagnostic prostate needle biopsy is associated with increased risk of PC-specific mortality. Our findings demonstrate that the prognostic effect of PNI is dependent on an association with high grade carcinoma and reactive stroma. However; the impact of PNI on clinical outcome becomes stronger and independent of other clinicopathologic factors upon increased percentage of PNI positive biopsy cores. Thus, our study highlights the importance of PNI and microenvironmental interactions for the long-term outcome of PC.

Intraprostatic injections for lower urinary tract symptoms treatment

PURPOSE OF REVIEW

The purpose of this study is to review and discuss recently published (2013-2014) experimental and clinical studies of intraprostatic injection therapy as an alternative treatment of lower urinary tract symptoms (LUTS).

RECENT FINDINGS

Recent focus has been on intraprostatic injection of botulinum toxin both with regard to mechanism of action and efficacy. In contrast to the promising findings in several previous studies, a recent large, randomized, placebo-controlled trial found no differences between onabotulinumtoxin A treatment and placebo. There is little new information on the use of anhydrous ethanol and agents such as NX-1207 and PRX302, which previously have been reported to have promising effects.

SUMMARY

Intraprostatic injection of different agents as a minimally invasive surgical therapy for LUTS associated with benign prostatic hyperplasia seems attractive and may have a potential as a treatment alternative, but so far, available results are not convincing. Further studies on the mechanisms of action of novel agents, and controlled clinical trials documenting their efficacy and side-effects when injected into the prostate are needed before their place in the treatment of benign prostatic hyperplasia/LUTS can be properly assessed.

Chronic stress, sympathetic activation and skeletal metastasis of breast cancer cells

Improved detection programs and new therapies significantly improved the 5-year survival rate of women with breast cancer. However, some women still relapse and succumb to cancer because of metastatic disease. In particular, chronically depressed patients do not seem to benefit from newly developed treatments and present with shorter survival. The reason for this association is unclear, but recent cues from preclinical studies point to the possible contribution of neuroendocrine factors generated in response to chronic stress and depression. Retrospective clinical studies also suggest a beneficial effect of sympathetic blockade in terms of less advanced disease at diagnosis, lower cancer-specific mortality, longer disease-free survival and reduced metastasis development and tumor recurrence, especially in patients who have taken propranolol before diagnosis. Therefore, β-blockers or therapies normalizing sympathetic tone might be beneficial as early adjuvant therapies to limit skeletal metastases and growth and eventually to improve prognosis in patients with breast cancers.

β-Adrenergic Receptor Signaling in Prostate Cancer

Enhanced sympathetic signaling, often associated with obesity and chronic stress, is increasingly acknowledged as a contributor to cancer aggressiveness. In prostate cancer, intact sympathetic nerves are critical for tumor formation, and sympathectomy induces apoptosis and blocks tumor growth. Perineural invasion, involving enrichment of intra-prostatic nerves, is frequently observed in prostate cancer and is associated with poor prognosis. β₂-adrenergic receptor (ADRB2), the most abundant receptor for sympathetic signals in prostate luminal cells, has been shown to regulate trans-differentiation of cancer cells to neuroendocrine-like cells and to affect apoptosis, angiogenesis, epithelial–mesenchymal transition, migration, and metastasis. Epidemiologic studies have shown that use of β-blockers, inhibiting β-adrenergic receptor activity, is associated with reduced prostate cancer-specific mortality. In this review, we aim to present an overview on how β-adrenergic receptor and its downstream signaling cascade influence the development of aggressive prostate cancer, primarily through regulating neuroendocrine differentiation.

Development of a P2X1-purinoceptor mediated contractile response in the aged mouse prostate gland through slowing down of ATP breakdown

AIMS

An age-related increase in prostatic smooth muscle tone is partly responsible for the lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH). Changes in the effectors of prostatic smooth muscle contraction with age may play a role in the development of these symptoms. Using a mouse model of prostate contractility, this study investigated the effect of age on the different components of contractility in the prostate gland.

METHODS

The isometric force developed in response to electrical field stimulation or exogenously applied agonists by mouse prostates mounted in organ baths, was evaluated to determine the effect of age on contractile mechanisms. Changes with age in the rate of ATP breakdown and levels of the P2rx1 gene and P2X1-purinoceptor expression in mouse prostate were measured by a modified luciferin-luciferase assay, RT-PCR and western blot, respectively.

RESULTS

Nerve mediated contractile responses containing a component elicited by P2X1-purinoceptors were observed in prostates taken from aged mice, but not in prostates taken from young adult mice. Furthermore, the potency of the endogenous purinoceptor agonist ATP was 50-fold greater in aged mice, whereas the potency of its stable analogue α,β-metATP was unchanged. An age-related decrease in ATP metabolism was also observed.

CONCLUSIONS

With age, a purinergic contractile response to nerve stimulation develops in the mouse prostate gland due to a decrease in the rate of ATP breakdown. This may contribute to the increase in muscular tone observed in BPH and suggests that P2X1-purinoceptors are an additional target for the treatment of BPH.

Does the autonomic nervous system contribute to the initiation and progression of prostate cancer?

In the July 12 issue of Science magazine, researchers from the Albert Einstein College of Medicine, the Mount Sinai School of Medicine, the Durham VA Medical Centre and Duke University published an elegant study demonstrating that the sympathetic nervous system, acting through β2 and β3-adrenoceptors in the prostate, plays an important role in the initiation of prostate cancer, while the parasympathetic nervous system plays a role in the dissemination of tumour metastases via M1 muscarinic receptors. These findings are significant because they indicate that receptors associated with the autonomic nervous system may be viable targets for prostate cancer therapy.