Increased endogenous estrogen synthesis leads to the sequential induction of prostatic inflammation (prostatitis) and prostatic pre-malignancy

Sex diferences in serum and synovial fluid C-reactive protein concentration in healthy dogs

Differences between serum C-reactive protein (SCRP) and synovial fluid C-reactive protein (SFCRP) concentrations in healthy animals may be influenced by the sex of the individual and associated with various factors. The objective of this study was to evaluate the disparities in SCRP and SFCRP concentrations between females and males, as well as within each sex. Sixty healthy dogs (N = 60), comprising both sexes, were enrolled in the study. Peripheral blood and knee synovial fluid samples were collected for SCRP and SFCRP analysis, respectively. Serum C-reactive protein (SCRP) and SFCRP concentrations were measured, with mean of 9.61 ± 4.96 mg/L for SCRP and 1.28 ± 3.05 mg/L for SFCRP. Notably, SFCRP concentrations were consistently lower than SCRP concentrations in both sexes. Statistically significant differences were observed between sexes for both SCRP (P = 0.021) and SFCRP (P = 0.007). Further analysis within females revealed statistically significant differences between SCRP and SFCRP concentrations (P = 0.002), whereas in males, such differences were not significant (P = 0.175). Additionally, weak correlations were found between SCRP and SFCRP concentrations for both sexes (females r = 0.07; males r = 0.29). Joint capsule thickness was assessed using ultrasonography, revealing thicker joint capsules in males. A robust positive association was noted between joint capsule thickness and the SFCRP concentration in both sexes. These findings offer valuable insights into the dynamics of CRP in the context of joint health in male and female patients, elucidating the underlying pathological mechanisms of joint disease and inflammation. Overall, this underscores the importance of considering sex-specific factors in the assessment and management of joint health, as well as in the design and interpretation of studies involving SFCRP concentrations.

Hyperbaric oxygen preconditioning normalizes scrotal temperature, sperm quality, testicular structure, and erectile function in adult male rats subjected to exertional heat injury

Testicular hyperthermia has been noted in men who work in high ambient temperatures. Scrotal temperatures above the normal range caused germ cell loss in the testes and resulted in male subfertility. In adult male rats, exercising at a higher environmental temperature (36 °C with relative humidity of 50%, 52 min) caused exertional heat stroke (EHS) characterized by scrotal hyperthermia, impaired sperm quality, dysmorphology in testes, prostates and bladders, and erectile dysfunction. Here, we aim to ascertain whether hyperbaric oxygen preconditioning (HBOP: 100% O2 at 2.0 atm absolute [ATA] for 2 h daily for 14 days consequently before the onset of EHS) is able to prevent the problem of EHS-induced sterility, testes, prostates, and bladders dysmorphology and erectile dysfunction. At the end of exertional heat stress compared to normobaric air (NBA or non-HBOP) rats, the HBOP rats exhibited lower body core temperature (40 °C vs. 43 °C), lower scrotal temperature (34 °C vs. 36 °C), lower neurological severity scores (2.8 vs. 5.8), higher erectile ability, (5984 mmHg-sec vs. 3788 mmHg-sec), higher plasma testosterone (6.8 ng/mL vs. 3.5 ng/mL), lower plasma follicle stimulating hormone (196.3 mIU/mL vs. 513.8 mIU/mL), lower plasma luteinizing hormone (131 IU/L vs. 189 IU/L), lower plasma adrenocorticotropic hormone (5136 pg/mL vs. 6129 pg/mL), lower plasma corticosterone (0.56 ng/mL vs. 1.18 ng/mL), lower sperm loss and lower values of histopathological scores for epididymis, testis, seminal vesicle, prostate, and bladder. Our data suggest that HBOP reduces body core and scrotal hyperthermia and improves sperm loss, testis/prostate/bladder dysmorphology, and erectile dysfunction after EHS in rats.

Preclinical models and evaluation criteria of prostatitis

Prostatitis is a common urological condition that affects almost half of all men at some point in their life. The prostate gland has a dense nerve supply that contributes to the production of fluid to nourish sperm and the mechanism to switch between urination and ejaculation. Prostatitis can cause frequent urination, pelvic pain, and even infertility. Long-term prostatitis increases the risk of prostate cancer and benign prostate hyperplasia. Chronic non-bacterial prostatitis presents a complex pathogenesis, which has challenged medical research. Experimental studies of prostatitis require appropriate preclinical models. This review aimed to summarize and compare preclinical models of prostatitis based on their methods, success rate, evaluation, and range of application. The objective of this study is to provide a comprehensive understanding of prostatitis and advance basic research.

Preclinical and Clinical Research Models of Prostate Cancer: A Brief Overview

The incidence and mortality from prostate cancer (PCa) are on the rise which poses a major public health concern worldwide. In this narrative review, we have summarized the characteristics of major in vitro and in vivo PCa models including their utility in developing treatment strategies. Androgens, particularly, testosterone and dihydrotestosterone (DHT) activate the androgen receptor (AR) signaling pathway that facilitates the development and progression of castration resistant PCa. Several enzymes namely, CYP17A1, HSD17B, and SRD5A are essential to furnishing DHT from dehydroepiandrosterone in the classical pathway while DHT is formed from androstanediol in the backdoor pathway. The advancement in delineating the molecular heterogeneity of PCa has been possible through the development of several in vitro and in vivo research models. Generally, tissue culture models are advantageous to understand PCa biology and investigate the efficacy and toxicity of novel agents; nevertheless, animal models are indispensable to studying the PCa etiology and treatment since they can simulate the tumor microenvironment that plays a central role in initiation and progression of the disease. Moreover, the availability of several genetically engineered mouse models has made it possible to study the metastasis process. However, the conventional models are not devoid of limitations. For example, the lack of heterogeneity in tissue culture models and the variation of metastatic characteristics in xenograft models are obviously challenging. Additionally, due to the racial and ethnic disparities in PCa pathophysiology, a new model that can represent PCa encompassing different ethnicities is urgently needed. New models should continue to evolve to address the genetic and molecular complexities as well as to further elucidate the finer details of the steroidogenic pathway associated with PCa.

Exploring the Ion Channel TRPV2 and Testicular Macrophages in Mouse Testis

The cation channel TRPV2 is known to be expressed by murine macrophages and is crucially involved in their functionality. Macrophages are frequent cells of the mouse testis, an immune-privileged and steroid-producing organ. TRPV2 expression by testicular macrophages and possible changes associated with age or inflammation have not been investigated yet. Therefore, we studied testes of young adult and old wild-type (WT) and AROM⁺ mice, i.e., transgenic mice overexpressing aromatase. In these animals, inflammatory changes are described in the testis, involving active macrophages, which increase with age. This is associated with impaired spermatogenesis and therefore AROM⁺ mice are a model for male infertility associated with sterile inflammation. In WT animals, testicular TRPV2 expression was mapped to interstitial CD206⁺ and peritubular MHC II⁺ macrophages, with higher levels in CD206⁺ cells. Expression levels of TRPV2 and most macrophage markers did not increase significantly in old mice, with the exception of CD206. As the number of TRPV2⁺ testicular macrophages was relatively small, their possible involvement in testicular functions and in aging in WT mice remains to be further studied. In AROM⁺ testis, TRPV2 was readily detected and levels increased significantly with age, together with macrophage markers and TNF-α. TRPV2 co-localized with F4/80 in macrophages and further studies showed that TRPV2 is mainly expressed by unusual CD206⁺MHC II⁺ macrophages, arising in the testis of these animals. Rescue experiments (aromatase inhibitor treatment and crossing with ERαKO mice) restored the testicular phenotype and also abolished the elevated expression of TRPV2, macrophage and inflammation markers. This suggests that TRPV2⁺ macrophages of the testis are part of an inflammatory cascade initiated by an altered sex hormone balance in AROM⁺ mice. The changes in testis are distinct from the described alterations in other organs of AROM⁺, such as prostate and spleen. When we monitored TRPV2 levels in another immune-privileged organ, namely the brain, we found that levels of TRPV2 were not elevated in AROM⁺ and remained stable during aging. In the adrenal, which similar to the testis produces steroids, we found slight, albeit not significant increases in TRPV2 in both AROM⁺ and WT mice, which were associated with age. Thus, the changes in the testis are specific for this organ.

Mast Cell-Derived SAMD14 Is a Novel Regulator of the Human Prostate Tumor Microenvironment

Mast cells (MCs) are important cellular components of the tumor microenvironment and are significantly associated with poor patient outcomes in prostate cancer and other solid cancers. The promotion of tumor progression partly involves heterotypic interactions between MCs and cancer-associated fibroblasts (CAFs), which combine to potentiate a pro-tumor extracellular matrix and promote epithelial cell invasion and migration. Thus far, the interactions between MCs and CAFs remain poorly understood. To identify molecular changes that may alter resident MC function in the prostate tumor microenvironment, we profiled the transcriptome of human prostate MCs isolated from patient-matched non-tumor and tumor-associated regions of fresh radical prostatectomy tissue. Transcriptomic profiling revealed a distinct gene expression profile of MCs isolated from prostate tumor regions, including the downregulation of SAMD14, a putative tumor suppressor gene. Proteomic profiling revealed that overexpression of SAMD14 in HMC-1 altered the secretion of proteins associated with immune regulation and extracellular matrix processes. To assess MC biological function within a model of the prostate tumor microenvironment, HMC-1-SAMD14+ conditioned media was added to co-cultures of primary prostatic CAFs and prostate epithelium. HMC-1-SAMD14+ secretions were shown to reduce the deposition and alignment of matrix produced by CAFs and suppress pro-tumorigenic prostate epithelial morphology. Overall, our data present the first profile of human MCs derived from prostate cancer patient specimens and identifies MC-derived SAMD14 as an important mediator of MC phenotype and function within the prostate tumor microenvironment.

Exertional heat stroke on fertility, erectile function, and testicular morphology in male rats

The association of exertional heat stroke (EHS) and testicular morphological changes affecting sperm quality, as well as the association of EHS and hypothalamic changes affecting sexual behavior, has yet to be elucidated. This study aimed to elucidate the effects of EHS on fertility, erectile function, and testicular morphology in male rats. Animals were exercised at higher room temperature (36 ℃ relative humidity 50%) to induce EHS, characterized by excessive hyperthermia, neurobehavioral deficits, hypothalamic cell damage, systemic inflammation, coagulopathy, and multiple organ injury. In particular, EHS animals had erectile dysfunction (as determined by measuring the changes of intracavernosal pressure and mean arterial pressure in response to electrical stimulation of cavernous nerves). Rats also displayed testicular temperature disruption, poorly differentiated seminiferous tubules, impaired sperm quality, and atrophy of interstitial Leydig cells, Sertoli cells, and peri-tubular cells in the testicular tissues accompanied by no spermatozoa and broken cells with pyknosis in their seminal vesicle and prostatitis. These EHS effects were still observed after 3 days following EHS onset, at least. Our findings provide a greater understanding of the effect of experimentally induced EHS on masculine sexual behavior, fertility, stress hormones, and morphology of both testis and prostate.

Resveratrol could attenuate prostatic inflammation in rats with Oestradiol-induced chronic prostatitis

To evaluate the effect of resveratrol in rats with chronic prostatitis, 24 rats were randomly divided into the negative control, vehicle-treated and resveratrol groups. The rats in the vehicle-treated group and the resveratrol group were injected subcutaneously with 17-β-oestradiol (0.25 mg/kg) daily for 6 weeks while the rats in the control group were injected with equivalent normal saline. From the 45th day, the rats in the resveratrol group were given resveratrol (10 mg/kg) by gavage per day while the rest rats were given normal saline. After 55 days, all the rats were sacrificed and the prostatic tissue was removed. Morphological changes were examined by light microscope after H&E staining. The expressions of IL-6, IL-8 and TNF-α were determined through ELISA and immunohistochemical staining. As a result, significant inflammatory cell infiltration and fibroblastic hyperplasia were observed in prostatic stroma in the vehicle-treated group compared with the negative control group, as well as the high expression of IL-6, IL-8 and TNF-α. After resveratrol treatment, inflammatory cell infiltration and fibroblastic hyperplasia were shown prominently reduced. Meanwhile, the expression of IL-6, IL-8 and TNF-α was significantly suppressed. For conclusion, resveratrol could attenuate the prostatic inflammation and downregulate the expression of IL-6, IL-8 and TNF-α in rat with oestradiol-induced chronic prostatitis.

Absence of nuclear receptors LXRs impairs immune response to androgen deprivation and leads to prostate neoplasia

Chronic inflammation is now a well-known precursor for cancer development. Infectious prostatitis are the most common causes of prostate inflammation, but emerging evidence points the role of metabolic disorders as a potential source of cancer-related inflammation. Although the widely used treatment for prostate cancer based on androgen deprivation therapy (ADT) effectively decreases tumor size, it also causes profound alterations in immune tumor microenvironment within the prostate. Here, we demonstrate that prostates of a mouse model invalidated for nuclear receptors liver X receptors (LXRs), crucial lipid metabolism and inflammation integrators, respond in an unexpected way to androgen deprivation. Indeed, we observed profound alterations in immune cells composition, which was associated with chronic inflammation of the prostate. This was explained by the recruitment of phagocytosis-deficient macrophages leading to aberrant hyporesponse to castration. This phenotypic alteration was sufficient to allow prostatic neoplasia. Altogether, these data suggest that ADT and inflammation resulting from metabolic alterations interact to promote aberrant proliferation of epithelial prostate cells and development of neoplasia. This raises the question of the benefit of ADT for patients with metabolic disorders.

Interactive Effects of Perinatal BPA or DES and Adult Testosterone and Estradiol Exposure on Adult Urethral Obstruction and Bladder, Kidney, and Prostate Pathology in Male Mice

Obstructive voiding disorder (OVD) occurs during aging in men and is often, but not always, associated with increased prostate size, due to benign prostatic hyperplasia (BPH), prostatitis, or prostate cancer. Estrogens are known to impact the development of both OVD and prostate diseases, either during early urogenital tract development in fetal–neonatal life or later in adulthood. To examine the potential interaction between developmental and adult estrogen exposure on the adult urogenital tract, male CD-1 mice were perinatally exposed to bisphenol A (BPA), diethylstilbestrol (DES) as a positive control, or vehicle negative control, and in adulthood were treated for 4 months with Silastic capsules containing testosterone and estradiol (T+E2) or empty capsules. Animals exposed to BPA or DES during perinatal development were more likely than negative controls to have urine flow/kidney problems and enlarged bladders, as well as enlarged prostates. OVD in adult T+E2-treated perinatal BPA and DES animals was associated with dorsal prostate hyperplasia and prostatitis. The results demonstrate a relationship between elevated exogenous estrogen levels during urogenital system development and elevated estradiol in adulthood and OVD in male mice. These findings support the two-hit hypothesis for the development of OVD and prostate diseases.

Spatiotemporal Proteomics Reveals the Molecular Consequences of Hormone Treatment in a Mouse Model of Lower Urinary Tract Dysfunction

Benign prostatic hyperplasia and related lower urinary tract symptoms remain common, costly, and impactful issues for aging males. The etiology and pathogenesis are multifactorial and include steroid hormone changes and inflammation. Noninvasive markers could one day inform personalized medicine, but interindividual variation and lack of healthy age-matched controls hamper research. Experimental models are appealing for insight into disease mechanisms. Here, we present a spatiotemporal proteomics study in a mouse model of hormone-induced urinary dysfunction. Urine samples were collected noninvasively across time: before, during, and after disease onset. A microcomputed tomography analysis implicated the prostate as a spatially relevant contributor to bladder outlet obstruction. Prostates were collected after disease onset and compared with control mice. Notable changes in urine include proteins representing oxidative stress defense and acute phase inflammatory response processes. In the prostate, hormone treatment led to perturbations related to an oxidative stress response and H₂O₂ metabolism. Several protein changes coincided in both urine and the prostate tissue, including glutathione peroxidase 3, glutathione hydrolase 1 proenzyme, and vitamin D-binding protein. This study supports the concept of noninvasive urinary biomarkers for prostate disease diagnostics. Oxidative stress and acute phase inflammatory processes were identified as key consequences of hormone-induced bladder outlet obstruction. Future research into antioxidants and anti-inflammatories in prostate diseases appears promising.

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.

A jaboticaba extract prevents prostatic damage associated with aging and high-fat diet intake

Jaboticaba extract prevented the prostatic lesion development in aging and/or overweight mice, mainly interfering in cell proliferation, hormonal and angiogenesis pathways.

Targeting Wistar rat as a model for studying benign, premalignant and malignant lesions of the prostate

AIMS

The purpose of this study was to describe a suitable experimental model for studying aging-related prostate disorders including cancer.

MATERIALS AND METHODS

12-month old Wistar rats were kept in control conditions (n = 12) or treated (n = 16) for 6 months with Silastic implants filled with testosterone (T) and estradiol (E₂). After the experiment period (at 18 months of age), animals were euthanized and the prostate and other organs were harvested, dissected, weighed, and processed for morphological, ultrastructural and molecular analyses.

KEY FINDINGS

We demonstrated that male rats of Wistar strain nicely recapitulate the carcinogenesis process taking place in the aging prostate through the arising of benign, precancerous and malignant lesions, and above all yields a modest incidence of spontaneous PCa (~36%). Moreover, our results highlight that 100% incidence of PCa and precancerous lesions such as prostatic intraepithelial neoplasia and proliferative inflammatory atrophy were achieved in this rat strain after T + E₂ treatment, without changing the broad spectrum of changes that naturally emerge in the prostate at advanced ages. Such enhancement of precancerous lesions and tumors was linked to a decreased expression of E-cadherin and β-catenin in parallel with an increase in Vimentin and N-cadherin, hallmark modifications of epithelial-mesenchymal transition.

SIGNIFICANCE

Our findings provide solid evidence that aged Wistar rats may be an excellent model for studies regarding human prostate biology and related disorders including cancer.

Bone and body composition response to testosterone therapy vary according to polymorphisms in the CYP19A1 gene

PURPOSE

To evaluate the influence of single nucleotide polymorphisms (SNPs) of CYP19A1 on the response and susceptibility to side effects from testosterone therapy. This is a prospective, single-arm study of men with low-morning serum testosterone (<10.68 nmol/l) administered testosterone cypionate 200 mg intramuscularly every 2 weeks for 18 months.

METHODS

We measured areal bone mineral density (aBMD) and body composition by dual energy X-ray absorptiometry, tibial volumetric BMD and geometry by peripheral quantitative computer tomography, bone turnover markers by enzyme-linked immunosorbent assay, testosterone, and estradiol by liquid-chromatography/mass-spectroscopy, genotyping by microarray, CYP19A1 expression by quantitative polymerase chain reaction, hematocrit and prostate-specific antigen (PSA).

RESULTS

We enrolled 105 men (40-74-years-old). SNPs rs1062033 and rs700518 were associated with significant differences in outcomes at 18 months. The GG genotype in rs1062033 had significant increase in whole body aBMD, but had significant decrease in tibial bone size compared to the CG and CC genotypes. Body composition analysis showed that the CC genotype of rs1062033, and the AA genotype of rs700518, had significant increase in total lean and appendicular lean mass compared to CG and GG, and AG and GG, respectively. The GG genotype of rs700518 had significant increase in PSA (GG = 105.8 ± 23.3% vs. AG + AA = 53.4 ± 11.3%, p = 0.046) while hematocrit changes were comparable among genotypes. CYP19A1 expression was highest in GG genotype in both SNPs.

CONCLUSIONS

For the first time, we demonstrated that CYP19A1 SNPs influence response to testosterone therapy in hypogonadal men, highlighting the importance of genetic profiling in therapeutics even for common clinical conditions.

Key Role of Obesity in Genitourinary Tumors with Emphasis on Urothelial and Prostate Cancers

Background: In human populations, a certain amount of data correlate obesity/body mass index (BMI) with urothelial cancer (UC) and prostate cancer (PCa) occurrence, however this is not fully elucidated at all stages of disease. In an attempt to shed light on uncertain areas in such field, in the present review we illustrate the main molecular mechanisms linking obesity and cancer, focusing on the correlation between obesity and tumor risk, disease progression and response to chemo- and immunotherapy in patients with UC and the predictive/prognostic role of obesity in PCa patients treated with the currently available therapeutic approaches. Methods: We did a large-scale literature search on existing scientific websites focusing on keywords "obesity", "body mass index (BMI)", "urothelial cancer", "prostate cancer", "docetaxel", "cabazitaxel", "abiraterone acetate", "enzalutamide", and "radium223". Results: Many adipocytes-induced molecules support tumor proliferation through activation of various cellular pathways. The available evidence in the postoperative setting do the role of BMI in oncological outcomes prediction still not completely clear. Likewise, in metastatic UC patients controversial results link the role of obesity/BMI with clinical outcomes of tumor response to chemotherapy. Adipose stromal cells recruitment, induced by PCa cells, from white adipose tissue to the tumor sites inducing cell invasiveness was associated with poor survival. Conflicting data, although more oriented towards a better survival outcome, resulted in obese patients treated with docetaxel. In PCa cell-lines a certain cabazitaxel chemo resistance adipose stromal cells (ASC)-mediated was demonstrated. In metastatic castration-resistant PCa patients with high BMI (>25 kg/m2) receiving abiraterone acetate there were significant worse survival outcomes, while in enzalutamide patients BMI did not affect survival outcome. In radium 223 patients higher BMI significantly correlated with favorable overall survival. Conclusions: The main focus of this review was to understand the interplay between obesity/BMI and UC/PCa. Several pathogenic cellular pathways exploring the issue are discussed, opening the way to challenging tailored treatments on the basis of BMI. Improving the knowledge of molecular connections between obesity and UC and PCa could favor the development of new therapies likely reducing chemo- and immunotherapy drug resistance.

Main Inflammatory Cells and Potentials of Anti-Inflammatory Agents in Prostate Cancer

Prostate cancer is the most common type of cancer and the leading cause of cancer deaths among men in many countries. Preventing progression is a major concern for prostate cancer patients on active surveillance, patients with recurrence after radical therapies, and patients who acquired resistance to systemic therapies. Inflammation, which is induced by various factors such as infection, microbiome, obesity, and a high-fat diet, is the major etiology in the development of prostate cancer. Inflammatory cells play important roles in tumor progression. Various immune cells including tumor-associated neutrophils, tumor-infiltrating macrophages, myeloid-derived suppressor cells, and mast cells promote prostate cancer via various intercellular signaling. Further basic studies examining the relationship between the inflammatory process and prostate cancer progression are warranted. Interventions by medications and diets to control systemic and/or local inflammation might be effective therapies for prostate cancer progression. Epidemiological investigations and basic research using human immune cells or mouse models have revealed that non-steroidal anti-inflammatory drugs, metformin, statins, soy isoflavones, and other diets are potential interventions for preventing progression of prostate cancer by suppressing inflammation. It is essential to evaluate appropriate indications and doses of each drug and diet.

Benign Prostatic Hyperplasia and Lower Urinary Tract Symptoms: What Is the Role and Significance of Inflammation?

PURPOSE OF REVIEW

The purpose of this review is to summarize the role and significance of inflammation as a putative additional factor contributing to lower urinary tract symptoms and the progression of benign prostatic hyperplasia. We review (1) the histologic definition of prostatic inflammation and its prevalence, (2) the effects inflammation in the prostate including on risk of acute urinary retention, and (3) the effects of systemic inflammation on the prostate and on voiding.

RECENT FINDINGS

Inflammation is a highly prevalent finding in the prostate, both on a histological and biochemical level. Men with inflammation have higher IPSS scores and increased prostate size; however, these differences appear to be imperceptibly small. Men with inflammation do experience a significantly increased risk of developing acute urinary retention, an event that is associated with significant morbidity. Recently, attempts have been made to identify more specific biochemical markers of local inflammation, and to identify regional patterns of inflamed tissue within the prostate which may be associated with higher IPSS scores, accelerated progression, and AUR. The effects of systemic inflammatory states, most notably MetS, and their role in LUTS have also been examined. Inflammation is a common finding in prostates of aging men, but its contribution to lower urinary tract symptoms and benign prostatic hyperplasia progression appears to be small when considered as a clinically relevant entity. Advances in the understanding of different forms of inflammation, and their impact when experienced in different locations within the prostate, may refine this knowledge. Systemic inflammation affects voiding, including in the absence of a prostate, but again significant effects of systemic inflammation on the prostate itself are also difficult to demonstrate. Prostatic inflammation is associated with a significantly increased risk of acute urinary retention.

Oral exposure of rats to dienestrol during gestation and lactation: Effects on the reproductive system of male offspring

This study was aimed at determining whether dienestrol (DIES) affects reproduction in male offspring of rats following oral maternal exposure during gestation and lactation. Pregnant rats were treated from GD 6 to PND 21. Animals received 0 (control-vehicle), 0.75, 1.5, 3.12, 6.25, 12.5, 50, 75 μg/kg bw/d of DIES. A control group -without vehicle-was also included. High DIES concentrations caused abortions at 75 and 50 μg/kg bw/d, while at 12.5 μg/kg bw/d had still miscarriages. Ten male rats per group were kept alive until PND 90 to ensure sexual maturity. Body and organ weights, anogenital distance (AGD) at PNDs 21 and 90, biochemical and sperm parameters like motility, viability, morphology, spermatozoa and resistant spermatid counts, and histopathology for sexual organs and liver were determined. An increase in organ weight (liver and sexual organs) and a decrease in AGD due to vehicle were found. A reduction of sperm motility and viability, and an increase of abnormal sperm morphology were caused by DIES, which provoked a dose-dependent prostatitis. Maternal exposure to DIES induced toxicity on the reproductive system of the male offspring, which could affect the capacity of fertilization.

Obesity, Inflammation, and Prostate Cancer

The prevalence of obesity is increasing in the world, and obesity-induced disease, insulin-resistance, cardiovascular disease, and malignancies are becoming a problem. Epidemiological studies have shown that obesity is associated with advanced prostate cancer and that obese men with prostate cancer have a poorer prognosis. Obesity induces systemic inflammation via several mechanisms. High-fat diet-induced prostate cancer progresses via adipose-secretory cytokines or chemokines. Inflammatory cells play important roles in tumor progression. A high-fat diet or obesity changes the local profile of immune cells, such as myeloid-derived suppressor cells and macrophages, in prostate cancer. Tumor-associated neutrophils, B cells, and complements may promote prostate cancer in the background of obesity. Interventions to control systemic and/or local inflammation and changes in lifestyle may also be viable therapies for prostate cancer.

Rapamycin‑induced autophagy attenuates hormone‑imbalance‑induced chronic non‑bacterial prostatitis in rats via the inhibition of NLRP3 inflammasome‑mediated inflammation

Chronic non-bacterial prostatitis (CNBP) is a common urinary disease and no standard treatments are available at present. Although autophagy serves an important role in a variety of chronic diseases, its role in CNBP is yet to be fully elucidated. Therefore, the present study aimed to investigate the effects of rapamycin-induced autophagy on CNBP by establishing a rat model. In the present study, a total of 30 male Sprague-Dawley rats were randomly divided into three groups (n=10 per group): i) Control, in which rats underwent a sham operation; ii) the model (CNBP), in which rats were castrated and administered 17β-estradiol (0.25 mg/kg via subcutaneous injection) for 30 consecutive days; and iii) rapamycin treatment, in which rats were employed in accordance with the CNBP model, but also received a daily intraperitoneal injection of rapamycin (1 mg/kg) from the 16th day post-surgery for 15 days. Alterations in histology and the levels of autophagy-associated markers, and components of the NLRP3 inflammasome, were measured in the prostate tissues of the rats. The levels of molecules located further downstream of the NLRP3 inflammasome pathway, including interleukin (IL)-1β and IL-18, were also measured. The results demonstrated that, compared with the control group, increased infiltration levels of inflammatory cells and glandular epithelial degeneration were observed in the prostate tissues of rats with CNBP. Furthermore, a significant increase in the concentration of IL-1β and IL-18 in the serum, as well as the increased expression levels of NLRP3, ASC and caspase-1 in prostate tissues were also observed. In addition, reductions in the number of autophagosomes and the expression levels of autophagy-associated, including microtubule-associated protein 1 light chain 3β (LC3B) and Beclin 1, were also detected in the CNBP group; however, treatment with rapamycin reversed these effects. Collectively, the findings of the present study indicated that the NLRP3 inflammasome-mediated inflammatory response was activated by a hormonal imbalance in the prostate glands of rats; however, these effects may be suppressed via rapamycin-induced autophagy.

Intracrine Regulation of Estrogen and Other Sex Steroid Levels in Endometrium and Non-gynecological Tissues; Pathology, Physiology, and Drug Discovery

Our understanding of the intracrine (or local) regulation of estrogen and other steroid synthesis and degradation expanded in the last decades, also thanks to recent technological advances in chromatography mass-spectrometry. Estrogen responsive tissues and organs are not passive receivers of the pool of steroids present in the blood but they can actively modify the intra-tissue steroid concentrations. This allows fine-tuning the exposure of responsive tissues and organs to estrogens and other steroids in order to best respond to the physiological needs of each specific organ. Deviations in such intracrine control can lead to unbalanced steroid hormone exposure and disturbances. Through a systematic bibliographic search on the expression of the intracrine enzymes in various tissues, this review gives an up-to-date view of the intracrine estrogen metabolisms, and to a lesser extent that of progestogens and androgens, in the lower female genital tract, including the physiological control of endometrial functions, receptivity, menopausal status and related pathological conditions. An overview of the intracrine regulation in extra gynecological tissues such as the lungs, gastrointestinal tract, brain, colon and bone is given. Current therapeutic approaches aimed at interfering with these metabolisms and future perspectives are discussed.

Quercetin protects against chronic prostatitis in rat model through NF-κB and MAPK signaling pathways

BACKGROUND

Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) is a common disease of urology, of which the pathogenesis and therapy remain to be further elucidated. Quercetin has been reported to improve the symptoms of CP/CPPS patients. We aimed to verify the therapeutic effect of quercetin on CP/CPPS and identify the mechanism responsible for it.

METHODS

A novel CP/CPPS model induced with Complete Freund Adjuvant in Sprague Dawley rats was established and the prostates and blood specimens were harvested for further measurement after oral administration of quercetin for 4 weeks.

RESULTS

Increased prostate index and infiltration of lymphocytes, up-regulated expression of IL-1β, IL-2, IL-6, IL-17A, MCP1, and TNFα, decreased T-SOD, CAT, GSH-PX, and increased MDA, enhanced phosphorylation of NF-κB, P38, ERK1/2, and SAPK/JNK were detected in CP/CPPS rat model. Quercetin was identified to ameliorate the histo-pathologic changes, decrease the expression of pro-inflammatory cytokines IL-1β, IL-2, IL-6, IL-17A, MCP1, and TNFα, improve anti-oxidant capacity, and suppress the phosphorylation of NF-κB and MAPKs.

CONCLUSIONS

Quercetin has specific protective effect on CP/CPPS, which is mediated by anti-inflammation, anti-oxidation, and at least partly through NF-κB and MAPK signaling pathways.

Macrophage Cytokines Enhance Cell Proliferation of Normal Prostate Epithelial Cells through Activation of ERK and Akt

Macrophage infiltrations (inflammation) are associated with prostate disorders such as prostatitis, prostatic hyperplasia and prostate cancer. All prostate disorders have elevated cell proliferation, and are initiated from normal prostate epithelial cells. To date, the mechanism of how macrophages regulate normal prostate epithelial cell proliferation remains largely unknown. Using a 3D co-culture system, we here show that Raw 264.7 macrophages increased cell proliferation of normal prostate epithelial PZ-HPV-7 cells. In addition, these Raw 264.7 macrophages expressed higher levels of Ym1 and CD206. We further identify macrophage-secreted cytokines including CCL3, IL-1ra, osteopontin, M-CSF1 and GDNF as mediators for potentiating PZ-HPV-7 cell proliferation in 3D. All these cytokines differentially activated ERK and Akt. Blockade of both kinases through their inhibitors hindered macrophage-induced cell proliferation of PZ-HPV-7 cells. Hence, our data provide mechanistic insight of how inflammation may contribute to development of prostatic diseases at a very early stage through augment of cell proliferation of normal prostate epithelial cells.

Elevated seminal plasma estradiol and epigenetic inactivation of ESR1 and ESR2 is associated with CP/CPPS

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is associated with urinary tract symptoms and hormonal imbalances amongst others. The heterogeneous clinical presentation, unexplored molecular background and lack of prostate biopsies complicate therapy. Here, using liquid biopsies, we performed a comprehensive translational study on men diagnosed with CP/CPPS type III (n= 50; median age 39.8, range 23-65) and age-matched controls (n= 61; median age 36.8, range 20-69), considering biochemical parameters of blood and ejaculates, and epigenetic regulation of the estrogen receptor genes (ESR1 and ESR2) in leukocytes isolated from blood (systemic regulation) and in somatic cells isolated from ejaculates (local regulation). We found elevated 17β-estradiol (E2) levels in seminal plasma, but not in blood plasma, that was significantly associated with CP/CPPS and impaired urinary tract symptoms. In ejaculated somatic cells of CP/CPPS patients we found that ESR1 and ESR2 were both significantly higher methylated in CpG-promoters and expressionally down-regulated in comparison to controls. Mast cells are reported to contribute to CP/CPPS and are estrogen responsive. Consistent with this, we found that E2 -treatment of human mast cell lines (HMC-1 and LAD2) resulted in altered cytokine and chemokine expression. Interestingly, in HMC-1 cells, possessing epigenetically inactivated ESR1 and ESR2, E2 -treatment led to a reduced transcription of a number of inflammatory genes. Overall, these data suggest that elevated local E2 levels associate with an epigenetic down-regulation of the estrogen receptors and have a prominent role in CP/CPPS. Investigating E2 levels in semen could therefore serve as a promising biomarker to select patients for estrogen targeted therapy.

Basal Cells Show Increased Expression of Aromatase and Estrogen Receptor α in Prostate Epithelial Lesions of Male Aging Rats

Besides androgens, estrogen signaling plays a key role in normal development and pathologies of the prostate. Irreversible synthesis of estrogens from androgens is catalyzed by aromatase. Interestingly, animals lacking aromatase do not develop cancer or prostatitis, whereas those with overexpression of aromatase and, consequently, high estrogen levels develop prostatitis and squamous metaplasia via estrogen receptor 1 (ERα). Even with this evidence, the aromatase expression in the prostate is controversial. Moreover, little is known about the occurrence of age-dependent variation of aromatase and its association with histopathological changes commonly found in advanced age, a knowledge gap that is addressed herein. For this purpose, the immunoexpression of aromatase was evaluated in the prostatic complex of young adult to senile Wistar rats. ERα was also investigated, to extend our understanding of estrogen responsiveness in the prostate. Moderate cytoplasmic immunoreactivity for aromatase was detected in the glandular epithelium. Eventually, some basal cells showed intense staining for aromatase. The expression pattern for aromatase appeared similar in the normal epithelium when young and senile rats were compared; this result was corroborated by Western blotting. Conversely, in senile rats, there was an increase in the frequency of basal cells intensely stained for aromatase, which appeared concentrated in areas of intraepithelial proliferation and prostatitis. These punctual areas also presented increased ERα positivity. Together, these findings suggest a plausible source for hormonal imbalance favoring estrogen production, which, by acting through ERα, may favor the development of prostatic lesions commonly found in advanced age.

Inflammatory Cytokine Signaling during Development of Pancreatic and Prostate Cancers

Inflammation is essential for many diseases including cancer. Activation and recruitment of immune cells during inflammation result in a cytokine- and chemokine-enriched cell environment, which affects cancer development. Since each type of cancer has its unique tumor environment, effects of cytokines from different sources such as tumor-infiltrating immune cells, stromal cells, endothelial cells, and cancer cells on cancer development can be quite complex. In this review, how immune cells contribute to tumorigenesis of pancreatic and prostate cancers through their secreted cytokines is discussed. In addition, the cytokine signaling that tumor cells of pancreatic and prostate cancers utilize to benefit their own survival is delineated.

Goniothalamin and Celecoxib Effects During Aging: Targeting Pro-Inflammatory Mediators in Chemoprevention of Prostatic Disorders

BACKGROUND

Prostate is highly affected by aging, which lead to inflammatory disorders that can predispose to cancer development. Chemoprevention has emerged as a new therapeutic approach, intensifying studies evaluating the biological properties of new compounds. The aim of this study was to characterize the inflammatory responses in the prostate ventral lobe from senile mice treated with Goniothalamin (GTN), a promising natural compound with anti-inflammatory and antiproliferative properties. Its activity was compared to Celecoxib, an established nonsteroidal anti-inflammatory drug (NSAID).

METHODS

The animals were divided into: Control groups; Young (18-week-old FVB), Senile (52-week-old FVB). Treated groups: Senile-Goniothalamin (150 mg/kg orally), Senile-Celecoxib (10 mg/kg orally). The ventral lobe was collected after 4 weeks for light microscopy, immunohistochemistry, ELISA, and Western blotting analysis.

RESULTS

Both treatments were efficient in controlling the inflammatory process in the prostate from senile mice, maintaining the glandular morphology integrity. GTN reduced all inflammatory mediators evaluated (TNF-α, COX-2, iNOS) and different from Celecoxib, it also decreased the protein levels of NF-kB and p-NF-kB.

CONCLUSIONS

Finally, GTN and Celecoxib controlled inflammation in the prostate, and sensitized the senescent microenvironment to anti-inflammatory stimuli. Thus, both treatments are indicated as potential drugs in the prostatic diseases prevention during senescence. Prostate 77:838-848, 2017. © 2017 Wiley Periodicals, Inc.

Evidence of estrone-sulfate uptake modification in young and middle-aged rat prostate

High plasma exposure to estrogens is often associated with prostate cancer. Reducing this phenomenon may present therapeutic benefits. The involvement of estrone sulphate (E1S), the most abundant circulating estrogen in men, has been partially studied in this age-related pathology. To investigate the consequences of plasma E1S overload on blood and prostate sex steroid levels and inflammatory tissue responses, young and middle-aged male rats were treated with E1S with or without steroid sulfatase (STS) inhibitor STX64 for 21 consecutive days. A plasma and prostate tissue steroid profile was determined. STS activity, mRNA expression of E1S organic anion transporting polypeptides (slco1a2, slco2b1, slco4a1) and pro-inflammatory cytokines (Il1-beta, Il6, TNF-alpha) were evaluated in prostate tissue according to age and treatment group. A significant correlation between plasma and prostate steroid levels related to hormone treatment was observed in all rat age groups. However, while the E1S level in prostate tissue increased in middle-aged treated rats (p<0.0001), no significant variation was observed in young treated rats. The protective effect of STX64 during E1S infusion was observed by the maintenance of low free estrogen concentrations in both plasma and tissue. However, this protection was not associated with mRNA expression stability of pro-inflammatory cytokines in older rat prostate. These results suggest that E1S uptake in rat prostate cells increases during aging. Therefore, if a similar phenomenon existed in men, preventively reducing the STS activity could be of interest to limit uptake of estrogens in prostate when high E1S plasma level is assayed.

Immune Infiltration and Prostate Cancer

It is becoming increasingly clear that inflammation influences prostate cancer (PCa) development and that immune cells are among the primary drivers of this effect. This information has launched numerous clinical trials testing immunotherapy drugs in PCa patients. The results of these studies are promising but have yet to generate a complete response. Importantly, the precise immune profile that determines clinical outcome remains unresolved. Individual immune cell types are divided into various functional subsets whose effects on tumor development may differ depending on their particular phenotype and functional status, which is often shaped by the tumor microenvironment. Thus, this review aims to examine the current knowledge regarding the role of inflammation and specific immune cell types in mediating PCa progression to assist in directing and optimizing immunotherapy targets, regimens, and responses and to uncover areas in which further research is needed. Finally, a summary of ongoing immunotherapy clinical trials in PCa is provided.

A pro-tumourigenic loop at the human prostate tumour interface orchestrated by oestrogen, CXCL12 and mast cell recruitment

Prostate cancer is hormone-dependent and regulated by androgens as well as oestrogens. The tumour microenvironment also provides regulatory control, but the balance and interplay between androgens and oestrogens at the human prostate tumour interface is unknown. This study reveals a central and dominant role for oestrogen in the microenvironment, fuelling a pro-tumourigenic loop of inflammatory cytokines involving recruitment of mast cells by carcinoma-associated fibroblasts (CAFs). Mast cell numbers were increased in human PCa clinical specimens, specifically within the peritumoural stroma. Human mast cells were also shown to express ERα and ERβ, with oestradiol directly stimulating mast cell proliferation and migration as well as altered cytokine/chemokine expression. There was a significant shift in the oestrogen:androgen balance in CAFs versus normal prostatic fibroblasts (NPFs), with a profound increase to ER:AR expression. Androgen signalling is also reduced in CAFs, while ERα and ERβ transcriptional activity is not, allowing oestrogen to dictate hormone action in the tumour microenvironment. Gene microarray analyses identified CXCL12 as a major oestrogen-driven target gene in CAFs, and CAFs recruit mast cells via CXCL12 in a CXCR4-dependent manner. Collectively, these data reveal multicellular oestrogen action in the tumour microenvironment and show dominant oestrogen, rather than androgen, signalling at the prostatic tumour interface.

Aromatase transgenic upregulation modulates basal cardiac performance and the response to ischemic stress in male mice

Estrogen in females is conventionally considered a cardioprotective influence, but a role for estrogen in male cardioprotection has yet to be defined. Estrogen biosynthesis from testosterone is regulated by aromatase. Aromatase has recently been shown to be expressed in the adult heart, although little is known about its involvement in the regulation of myocardial function and stress responses. The goal of this study was to determine whether upregulation of tissue aromatase expression could improve ischemic resilience in male hearts. Isolated hearts from male transgenic aromatase-overexpressing (AROM+; high estrogen, low testosterone) mice and wild-type (WT) mice (12 wk) were Langendorff perfused and subjected to ischemia-reperfusion (25 min ischemia and 60 min of reperfusion). Basal systolic function was lower in AROM+ hearts (dP/d tmax: 4,121 ± 255 vs. 4,992 ± 283 mmHg/s, P < 0.05) and associated with augmented Akt phosphorylation, consistent with a suppressor action of estrogen on contractility. Ischemic contracture was attenuated in AROM+ hearts (43 ± 3 vs. 55 ± 4 mmHg, P < 0.05), yet AROM+ hearts were more arrhythmic in early reperfusion. At the end of 60 min of reperfusion, AROM+ systolic functional recovery was lower (left ventricular developed pressure: 39 ± 6 vs. 56 ± 5 %basal, P < 0.05) and diastolic dysfunction was accentuated (36 ± 4 vs. 24 ± 2 mmHg, P < 0.05). This is the first study to show that in vivo aromatase upregulation modulates basal cardiac performance and the response to ischemic stress. These data suggest that while chronic exposure to enhanced estrogenic influence may have benefits in limiting ischemic contracture severity, acute functional recovery in reperfusion is compromised. A temporally targeted, tissue-specific intervention combining aromatase treatment with inotropic support may offer therapeutic potential for men and women.

The role of inflammation in prostate cancer

In the United States and in "Westernized" countries, the prevalence of both prostate cancer and prostate inflammation is very high, indicating that the two pathologies could be causally related. Indeed, chronic inflammation is now regarded as an "enabling" characteristic of human cancer. Prostate cancer incidence is thought to be mediated in part by genetics, but also by environmental exposures, including the same exposures that may contribute to the development of prostatic inflammation. As our understanding of the role of inflammation in cancer deepens, it is increasingly apparent that "inflammation" as a whole is a complex entity that does not always play a negative role in cancer etiology. In fact, inflammation can play potentially dichotomous (both pro and antitumorigenic) roles depending on the nature and the cellular makeup of the immune response. This chapter will focus on reviewing the current state of knowledge on the role of innate and adaptive immune cells within the prostate tumor microenvironment and their seemingly complex role in prostate cancer in preventing versus promoting initiation and progression of the disease.

A preclinical xenograft model identifies castration-tolerant cancer-repopulating cells in localized prostate tumors

A lack of clinically relevant experimental models of human prostate cancer hampers evaluation of potential therapeutic agents. Currently, androgen deprivation therapy is the gold standard treatment for advanced prostate cancer, but inevitably, a subpopulation of cancer cells survives and repopulates the tumor. Tumor cells that survive androgen withdrawal are critical therapeutic targets for more effective treatments, but current model systems cannot determine when they arise in disease progression and are unable to recapitulate variable patient response to treatment. A model system was developed in which stromal-supported xenografts from multiple patients with early-stage localized disease can be tested for response to castration. The histopathology of these xenografts mimicked the original tumors, and short-term host castration resulted in reduced proliferation and increased apoptosis in tumor cells. After 4 weeks of castration, residual populations of quiescent, stem-like tumor cells remained. Without subsequent treatment, these residual cells displayed regenerative potential, because testosterone readministration resulted in emergence of rapidly proliferating tumors. Therefore, this model may be useful for revealing potential cellular targets in prostate cancer, which exist before the onset of aggressive incurable disease. Specific eradication of these regenerative tumor cells that survive castration could then confer survival benefits for patients.

Mast cells as a potential prognostic marker in prostate cancer

Despite years of intensive investigation that has been made in understanding prostate cancer, it remains one of the major men's health issues and the leading cause of death worldwide. It is now ascertained that prostate cancer emerges from multiple spontaneous and/or inherited alterations that induce changes in expression patterns of genes and proteins that function in complex networks controlling critical cellular events. It is now accepted that several innate and adaptive immune cells, including T- and B-lymphocytes, macrophages, natural killer cells, dendritic cells, neutrophils, eosinophils, and mast cells (MCs), infiltrate the prostate cancer. All of these cells are irregularly scattered within the tumor and loaded with an assorted array of cytokines, chemokines, and inflammatory and cytotoxic mediators. This complex framework reflects the diversity in tumor biology and tumor-host interactions. MCs are well-established effector cells in Immunoglobulin-E (Ig-E) associated immune responses and potent effector cells of the innate immune system; however, their clinical significance in prostate cancer is still debated. Here, these controversies are summarized, focusing on the implications of these findings in understanding the roles of MCs in primary prostate cancer.

Variations in circulating sex steroid levels in metastatic prostate cancer patients with combined androgen blockade: observation and implication

Testosterone is the major precursor of estradiol (E2) in men. We hypothesized that, in metastatic prostate cancer, androgen deprivation therapy suppression of serum androgen to the castration level may also disrupt serum E2 level, and variation in serum E2 level might play a role in the development of castration-resistant prostate cancer. Our investigation was designed to observe the variation in circulating oestrogen and androgen levels in metastatic prostate cancer patients after combined androgen blockade, and to explore the possible clinical significance. We recruited 105 consecutive metastatic prostate cancer patients who were treated with combined androgen blockade from June to August 2011, and divided them into three groups according to different hormone-sensitivity status, including 58 hormone-sensitive prostate cancers, 27 after failure of first-line hormone therapy (androgen-independent prostate cancer) and 20 castration-resistant prostate cancers. Another 36 consecutive patients with treatment-naive metastatic prostate cancer during the same period were used as controls. Serum testosterone, E2 and E2/testosterone (E2/T) ratio were analysed and compared between the groups. After combined androgen blockade, testosterone was suppressed to a low level, regardless of different hormone sensitivity (p > 0.05). Mean serum testosterone was 4.07, 0.15, 0.11 and 0.09 ng/mL in treatment-naive, hormone-sensitive, androgen-independent and castration-resistant prostate cancer respectively. For each group, mean E2 was 33.06, 9.23, 9.13 and 15.05 pg/mL respectively. Mean E2/T was 9.58, 269.29, 292.06 and 996.67 respectively. Recovery of E2 and increased E2/T ratio were more significantly associated with combined androgen blockade failure, especially in castration-resistant prostate cancer (p < 0.001). This study indicated that metabolism of oestrogen might change during combined androgen blockade in metastatic prostate cancer patients, and oestrogen-related pathways might play a role in the development of castration-resistant prostate cancer.

Development of animal models underlining mechanistic connections between prostate inflammation and cancer

The characterization of animal models has indicated that the genetic, dietary and environmental factors and hormonal imbalance may influence the risk to develop prostate inflammatory lesions and prostate cancer (PC) confirming human epidemiologic data. It is now established that the prostate inflammatory response typically results in major changes in the local microenvironment of epithelial cells of the prostate gland, including an intense stromal remodeling, activation of fibroblasts, infiltration of immune cells such as mast cells, macrophages and B and T lymphocytes and collagen deposition. The immune cells recruited at prostate inflammatory lesions and myofibroblasts may contribute to the release of numerous pro-inflammatory cytokines and chemokines that in turn can promote the oxidative stress, genomic instability and proliferation of epithelial cells. The accumulation of additional genetic and/or epigenetic alterations in prostatic stem/progenitor cells may subsequently culminate to their malignant transformation and PC initiation and progression and more particularly with advancing age. The potential mechanistic relationships between the molecular events associated with the persistent inflammatory response and prostate carcinogenesis have important implications for optimizing the current therapies against different prostatic disorders and PCs.

Circulating sex steroids and prostate cancer: introducing the time-dependency theory

PURPOSE

We sought whether serum total testosterone (tT), estradiol (E2), tT/E2 ratio, and sex hormone-binding globulin (SHBG) significantly fluctuate throughout time in men with prostate cancer (PCa).

METHODS

Circulating hormones were measured in a cohort of 631 candidates for radical prostatectomy. Hormone levels were analyzed according to either patient age, stratified into quartiles, or body mass index (BMI). Linear regression analyses tested the association between sex steroids and continuously coded patient age and BMI values.

RESULTS

No significant differences were found among age quartiles regarding serum tT levels and tT/E2 ratio. Conversely, E2 and SHBG levels significantly increased throughout time (all, p ≤ 0.001). Total T did not linearly change according to continuously coded patient age; in contrast, E2 and SHBG linearly increased (all, p ≤ 0.001), whereas tT/E2 decreased (p = 0.016) with aging. Rate of hypogonadism significantly increased with aging (p = 0.04). Total T, T/E2 ratio, and SHBG linearly decreased along with BMI increases (all p ≤ 0.02), whereas serum E2 did not significantly change. Rate of hypogonadism significantly increased with BMI increases (p < 0.001).

CONCLUSIONS

In contrast with longitudinal studies in the general male population, these data indirectly suggest that serum tT levels could be stable over time in PCa patients. This finding led to formulation of a "time-dependency theory", which postulates that the endocrine biology of prostate tissue is dependent on the exposure time at a given concentration of sex steroid, which, in turn, fluctuates throughout the lifespan of the individual.

Human epithelial basal cells are cells of origin of prostate cancer, independent of CD133 status

Normal prostatic epithelium is composed of basal and luminal cells. Prostate cancer can be initiated in both benign basal and luminal stem cells, but because basal cell markers are not expressed in patient tumors, the former result was unexpected. Since the cells of origin of prostate cancer are important therapeutic targets, we sought to provide further proof that basal stem cells have tumorigenic potential. Prostatic basal cells were enriched based on α2β1integrin(hi) expression and further enriched for stem cells using CD133 in nontumorigenic BPH-1 cells. Human embryonic stem cells (hESCs) were also used as a source of normal stem cells. To test their tumorigenicity, we used two alternate stromal-based approaches; (a) recombination with human cancer-associated fibroblasts (CAFs) or (b) recombination with embryonic stroma (urogenital mesenchyme) and treated host mice with testosterone and 17β-estradiol. Enriched α2β1integrin(hi) basal cells from BPH-1 cells resulted in malignant tumor formation using both assays of tumorigenicity. Surprisingly, the tumorigenic potential did not reside in the CD133(+) stem cells but was consistently observed in the CD133(-) population. CAFs also failed to induce prostatic tumors from hESCs. These data confirmed that benign human basal cells include cells of origin of prostate cancer and reinforced their importance as therapeutic targets. In addition, our data suggested that the more proliferative CD133(-) basal cells are more susceptible to tumorigenesis compared to the CD133(+)-enriched stem cells. These findings challenge the current dogma that normal stem cells and cells of origin of cancer are the same cell type(s).

Inflammation and prostate carcinogenesis

Quite a few epidemiological studies including meta-analyses indicate that prostate inflammation is associated with increased risk of prostate cancer. The cause of inflammation in the prostate is speculated to be several microorganisms that cause prostatitis or sexually transmitted infections. Other specific microorganisms, such as xenotropic murine leukemia virus-related virus, are also reported to relate to the development of prostate cancer; however, the contribution of this microorganism to prostate cancer development needs to be carefully interpreted. Environmental factors, especially dietary factors, might also be associated with prostate cancer development. Among related dietary factors, charred meat carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine might be a link between environmental factors and inflammation, because 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine has the potential to accelerate prostate inflammation through its estrogenic effect. In light of these findings, preventing or reducing prostate inflammation might be one strategy for chemoprevention of prostate cancer.