Immunohistochemical localization of protein gene product 9.5, ubiquitin, and neuropeptide Y immunoreactivities in epithelial and neuroendocrine cells from normal and hyperplastic human prostate

Cocaine and amphetamine regulated transcript (CART): a newly characterized neuropeptide in human prostate

Cocaine and amphetamine regulated transcript (CART) is a somatostatin-like polypeptide. CART has been localized in the CNS, hypothalamo-pituitary-adrenocortical (HPA) axis, pancreatic islets and enteric nervous system. We investigated the cellular localization of CART in normal human prostate, benign prostatic hyperplasia, prostatic intraepithelial neoplasia and acinar adenocarcinoma. CART was assessed using immunohistochemistry (IHC) and in situ hybridization (ISH), and its gene expression was identified by RTqPCR. We found cellular expression of CART in both normal prostatic luminal secretory epithelial cells neuroendocrine cells (NEC) of both ducts and acini. The cellular appearance indicated a cycle of neuropeptide synthesis and secretion as validated by ISH/IHC concordance. RTqPCR analysis also validated the immunohistochemical data and gene expression, which both indicated low to moderate expression in prostatic tissues. CART expression also was increased in both neuroendocrine and glandular epithelial cell populations from samples of benign prostatic hyperplasia as validated by IHC, ISH and RTqPCR. CART expression was markedly diminished and, in some cases, entirely absent in tissues of prostatic intraepithelial neoplasia and adenocarcinoma. Owing to loss of CART expression in adenocarcinoma and its increase in benign prostatic hyperplasia, CART may prove to be an important prostate marker.

Increased Density of Growth Differentiation Factor-15+ Immunoreactive M1/M2 Macrophages in Prostate Cancer of Different Gleason Scores Compared with Benign Prostate Hyperplasia

Simple Summary

Prostate cancer (PCa) is the second most diagnosed cancer and cause of death in men worldwide. The main challenge is to discover biomarkers for malignancy to guide the physician towards optimized diagnosis and therapy. There is recent evidence that growth differentiation factor-15 (GDF-15) is elevated in cancer patients. Therefore, we aimed to decipher GDF-15+ cell types and their density in biopsies of human PCa patients with Gleason score (GS)6–9 and benign prostate hyperplasia (BPH). Here we show that the density of GDF-15+ cells, mainly identified as interstitial macrophages (MΦ), was higher in GS6–9 than in BPH, and, thus, GDF-15 is intended to differentiate patients with high GS vs. BPH, as well as GS6 vs. GS7 (or even with higher malignancy). Some GDF-15+ MΦ showed a transepithelial migration into the glandular lumen and, thus, might be used for measurement in urine/semen. Taken together, GDF-15 is proposed as a novel tool to diagnose PCa vs. BPH or malignancy (GS6 vs. higher GS) and as a potential target for anti-tumor therapy. GDF-15 in seminal plasma and/or urine could be utilized as a non-invasive biomarker of PCa as compared to BPH.

Abstract

Although growth differentiation factor-15 (GDF-15) is highly expressed in PCa, its role in the development and progression of PCa is unclear. The present study aims to determine the density of GDF-15+ cells and immune cells (M1-/M2 macrophages [MΦ], lymphocytes) in PCa of different Gleason scores (GS) compared to BPH. Immunohistochemistry and double immunofluorescence were performed on paraffin-embedded human PCa and BPH biopsies with antibodies directed against GDF-15, CD68 (M1 MΦ), CD163 (M2 MΦ), CD4, CD8, CD19 (T /B lymphocytes), or PD-L1. PGP9.5 served as a marker for innervation and neuroendocrine cells. GDF-15+ cell density was higher in all GS than in BPH. CD68+ MΦ density in GS9 and CD163+ MΦ exceeded that in BPH. GDF-15+ cell density correlated significantly positively with CD68+ or CD163+ MΦ density in extratumoral areas. Double immunoreactive GDF-15+/CD68+ cells were found as transepithelial migrating MΦ. Stromal CD68+ MΦ lacked GDF-15+. The area of PGP9.5+ innervation was higher in GS9 than in BPH. PGP9.5+ cells, occasionally copositive for GDF-15+, also occurred in the glandular epithelium. In GS6, but not in BPH, GDF-15+, PD-L1+, and CD68+ cells were found in epithelium within luminal excrescences. The degree of extra-/intra-tumoral GDF-15 increases in M1/M2Φ is proposed to be useful to stratify progredient malignancy of PCa. GDF-15 is a potential target for anti-tumor therapy.

Distribution, shape, and immunohistochemical characteristics of serotonin-immunoreactive neuroendocrine cells in the urethra and periurethral genital organs in mice

The aim of this study is to clarify the disibution, shape, and immunohistochemical characteristics of serotonin-immunoreactive neuroendocrine cells (SIR-NECs) in mouse prostate and in the surrounding genital organs by histological and immunohistochemical analysis of the light microscopic serial sections of urethra. We collected lower urinary tracts from 13-week-old mice and observed the distribution pattern and shape of the SIR-NECs by serial light microscopy. The organs on the sections were divided into three anatomical zones to clarify the distribution pattern of SIR-NECs: (1) zone A, the ducts near the prostatic urethra; (2) zone B, the ducts outside the urethral sphincter; and (3) zone C, the acinus areas. Sections were double immune-stained with antibodies against serotonin and one of neuroendocrine-related factors (NRFs), including 10 neural cell markers and eight neurotransmitters, and also 4',6-diamino-2-phenylindole (DAPI). In addition, SIR-NECs were double immune-stained with antibodies against cytokeratin 5 (CK5) and p63, together with DAPI. SIR-NECs were mostly localized in zone A, and no SIR-NECs were observed in zone C. The proportion of flask-shaped SIR-NECs was approximately 15% in zones A and B. No flask-shaped SIR-NECs were observed in urethral epithelia. The NRFs co-localized with SIR-NEC were calcitonin gene-related peptide, CD56, chromogranin A, neuron-specific enolase, neuron cytoplastic protein 9.5, and synaptophysin (72.3%, 73.2%, 88.9%, 92.3%, 91.7%, and 81.9%, respectively). CK5 and p63 were not co-localized with SIR-NECs.　In this study, SIR-NEC of the urethra and the surrounding genital organs was ubiquitous in the urethra and the ducts near the urethra and co-expressed specific nerve-related NRFs.

Investigation of Neural Microenvironment in Prostate Cancer in Context of Neural Density, Perineural Invasion, and Neuroendocrine Profile of Tumors

Background

Cancer stroma contains the neural compartment with specific components and action. Neural microenvironment processing includes among others axonogenesis, perineural invasion (PNI), neurosignaling, and tumor cell neural/neuroendocrine differentiation. Growing data suggest that tumor-neural crosstalk plays an important function in prostate cancer (PCa) biology. However, the mechanisms involved in PNI and axonogenesis, as well as their patho-clinical correlations in this tumor are unclear.

Methods

The present study was carried out on FFPE samples of 73 PCa and 15 benign prostate (BP) cases. Immunohistochemistry with neural markers PGP9.5, TH, and NFP was performed on constructed TMAs and selected tissue sections. The analyzed parameters of tumor innervation included small nerve density (ND) measured on pan-neural marker (PGP9.5) and TH s4tained slides, as well assessment of PNI presence and morphology. The qualitative and topographic aspects were studied. In addition, the expression of neuroendocrine marker chromogranin and NPY was assessed with dedicated indexes. The correlations of the above parameters with basic patho-clinical data such as patients’ age, tumor stage, grade, angioinvasion, and ERG status were examined.

Results

The study showed that innervation parameters differed between cancer and BP. The neural network in PCa revealed heterogeneity, and ND PGP9.5 in tumor was significantly lower than in its periphery. The density of sympathetic TH-positive fibers and its proportion to all fibers was lower in cancer than in the periphery and BP samples. Perineural invasion was confirmed in 76% of cases, usually multifocally, occurring more commonly in tumors with a higher grade. NPY expression in PCa cells was common with its intensity often rising towards PNI. ERG+ tumors showed higher ND, more frequent PNI, and a higher stage. Moreover, chromogranin-positive cells were more pronounced in PCa with higher NPY expression.

Conclusions

The analysis showed an irregular axonal network in prostate cancer with higher neural density (panneural and adrenergic) in the surroundings and the invasive front. ND and PNI interrelated with NPY expression, neuroendocrine differentiation, and ERG status. The above findings support new evidence for the presence of autocrine and paracrine interactions in prostate cancer neural microenvironment.

Effects of testosterone replacement on serotonin levels in the prostate and plasma in a murine model of hypogonadism

Benign prostate hyperplasia is a dysfunctional disease with an elevated prevalence. Despite the accepted impact of aging and testosterone (TES) in its pathophysiology, its aetiology remains unknown. Recent studies described that serotonin (5-HT) inhibits benign prostate growth through the modulation of the androgen receptor, in the presence of TES. Accordingly, this work aimed to determine the impact of castration and TES replacement in plasmatic and prostatic 5-HT regulation. C57BL/6 mice were submitted to surgical castration and divided into three groups, continually exposed to either vehicle or different TES doses for 14 days. Plasmatic 5-HT concentration was measured before and after castration, and after TES reintroduction. Finally, total prostatic weight and intra-prostatic 5-HT were determined in the different groups. Our results demonstrate that mice prostate exhibits high 5-HT tissue levels and that intra-prostatic total 5-HT was independent of castration or TES reintroduction, in all studied groups. Also, 5-HT plasmatic concentration significantly increased after castration and then normalized after TES administration. Our findings revealed that mice prostate has a high 5-HT content and that total prostatic 5-HT levels do not depend on androgens' action. On the other hand, castration induced a significant increase in plasmatic 5-HT concentration, raising the hypothesis that androgens might be regulating the production of extra-prostatic 5-HT.

Serotonin regulates prostate growth through androgen receptor modulation

Aging and testosterone almost inexorably cause benign prostatic hyperplasia (BPH) in Human males. However, etiology of BPH is largely unknown. Serotonin (5-HT) is produced by neuroendocrine prostatic cells and presents in high concentration in normal prostatic transition zone, but its function in prostate physiology is unknown. Previous evidence demonstrated that neuroendocrine cells and 5-HT are decreased in BPH compared to normal prostate. Here, we show that 5-HT is a strong negative regulator of prostate growth. In vitro, 5-HT inhibits rat prostate branching through down-regulation of androgen receptor (AR). This 5-HT’s inhibitory mechanism is also present in human cells of normal prostate and BPH, namely in cell lines expressing AR when treated with testosterone. In both models, 5-HT’s inhibitory mechanism was replicated by specific agonists of 5-Htr1a and 5-Htr1b. Since peripheral 5-HT production is specifically regulated by tryptophan hydroxylase 1(Tph1), we showed that Tph1 knockout mice present higher prostate mass and up-regulation of AR when compared to wild-type, whereas 5-HT treatment restored the prostate weight and AR levels. As 5-HT is decreased in BPH, we present here evidence that links 5-HT depletion to BPH etiology through modulation of AR. Serotoninergic prostate pathway should be explored as a new therapeutic target for BPH.

Immunohistochemical Detection of Protein Gene Product 9.5 (PGP 9.5) in Canine Epitheliotropic T-Cell Lymphoma (Mycosis Fungoides)

Protein gene product 9.5 (PGP 9.5), a ubiquitin COOH-terminal hydrolase initially considered specific for neural and neuroendocrine tissues, is expressed in a variety of epithelial and mesenchymal tumors. During immunohistochemical evaluation of a cutaneous epitheliotropic T-cell lymphoma (mycosis fungoides [MF]) in a dog, strong reactivity for PGP 9.5 was observed. This unexpected result prompted us to examine PGP 9.5 immunoreactivity in 13 additional cases of canine mycosis fungoides. All tumors were confirmed as T-cell epitheliotropic lymphoma by histopathology and immunohistochemistry for CD3. Eight of 14 cases were positive for PGP 9.5, with reactivity mainly in the cytoplasm and less commonly in the nucleus. One case had strong reactivity in the cell membrane, sometimes with concurrent paranuclear staining. Immunoreactivity did not correlate with location (epidermal, dermal, and adnexal) of tumor cells. Disease outcome did not vary between PGP 9.5-positive and negative tumors. Although PGP 9.5 immunoreactivity in MF did not predict tumor behavior in these dogs, it has had prognostic value in certain human carcinomas. This unexpected staining of lymphocytes in mycosis fungoides with an antibody to PGP 9.5 demonstrates its presence in nonneuroendocrine tumors and precludes its use as the sole diagnostic marker in discrete cell tumors in the skin.

Neuroendocrine cells are present in the domestic fowl ovary

Neuroendocrine cells are present in virtually all organs of the vertebrate body; however, it is yet uncertain whether they exist in the ovaries. Previous reports of ovarian neurons and neuron-like cells in mammals and birds might have resulted from misidentification. The aim of the present work was to determine the identity of neuron-like cells in immature ovaries of the domestic fowl. Cells immunoreactive to neurofilaments, synaptophysin, and chromogranin-A, with small, dense-core secretory granules, were consistently observed throughout the sub-cortical ovarian medulla and cortical interfollicular stroma. These cells also displayed immunoreactivity for tyrosine, tryptophan and dopamine β-hydroxylases, as well as to aromatic L-DOPA decarboxylase, implying their ability to synthesize both catecholamines and indolamines. Our results support the argument that the ovarian cells previously reported as neuron-like in birds, are neuroendocrine cells.

Stereological Quantification of Nerve Fibers Immunoreactive to PGP 9.5, NPY, and VIP in Rat Prostate During Postnatal Development

This work was undertaken to study prostate innervation during the postnatal development of rats. It deals with the quantification of nervous fibers throughout all the regions of the rat prostate during the postnatal development using a general marker for nervous tissue, protein gene product 9.5, and 2 neuropeptides (NPY and VIP). Forty male Wistar rats (prepubertals, pubertals, young, and aged adults) were studied for immunohistochemistry of protein gene product (PGP 9.5), neuropeptide Y (NPY), and vasoactive intestinal polypeptide (VIP). They were also evaluated for length density of nerve fibers (L(V) PGP 9.5, L(V) NPY, L(V) VIP). Nerve fibers immunoreactive to the 3 antigens studied were detected in all the groups and in all the prostate zones. Periductal L(V) NPY evidenced a significant increase in the pubertal group, maintained throughout adult life. Periductal L(V) VIP showed a significant increase in young adults. The length densities of VIP and NPY fibers were significantly higher in periductal and ampular locations in comparison with dorsal and ventral sites. It can be concluded that the relative amount of nerve fibers in rat prostate, detected by PGP 9.5, does not change during postnatal development. There were significant changes in NPY and VIP fibers, showing an increase in periurethral ducts at puberty. The abundance of peptidergic innervation around the excretory ducts is related to their contractility. The development of innervation of periurethral ducts is regulated by androgens.

Localization of nerve fibers in colonic polyps, adenomas, and adenocarcinomas by immunocytochemical staining for PGP 9.5

BACKGROUND

PGP 9.5 is a cytoplasmic protein and is a specific marker for neurites and neurons.

AIMS

Using anti-PGP 9.5, this study aimed to localize nerve fibers in normal colons, polyps, adenomas and adenocarcinomas.

METHODS

Colonic polyps, adenomas and T(1) to T(3) adenocarcinomas with adjacent normal colon were immunostained for PGP 9.5 using rabbit anti-PGP 9.5.

RESULTS

In normal colon, numerous nerve fibers were localized in inner and outer muscles, from which submucosa and lamina propria were innervated. In hyperplastic polyps and tubular adenomas, the stalk revealed Meissner's plexus and large-diameter nerve fibers, and fine nerve fibers innervated abundantly in lamina propria of hyperplastic polyps and small tubular adenomas. In villous adenomas, large-diameter nerve fibers and Meissner's plexus were localized in the stalk whereas a few or no fine nerve fibers were localized in fine stroma. In adenocarcinomas, more fine fibers were localized in submucosal stroma adjacent to the invading carcinoma in T(1) carcinomas but there were no nerve fibers in the midst of tumors in T(2) and T(3) carcinomas. There were focally and sporadically increased nerve fibers adjacent to invading cancer nests in 5 of 8 T(2) cases. In T(3) carcinomas, fragmented Auerbach's plexus were noted in cancer-invaded colonic muscles and there were no increased fine nerve fibers in the cancer-invaded subserosa in the majority of cases. PGP 9.5 immunostaining revealed tumor-associated neurogenesis in submucosa but no obviously increased nerve fibers within cancer-invaded muscles.

CONCLUSIONS

This lack of tumor-associated neurogenesis supports insidious and often silent clinical presentation of colonic carcinomas until invading through the colonic wall to adjacent organs.

Distribution of GABAergic interneurons and dopaminergic cells in the functional territories of the human striatum

Background

The afferent projections of the striatum (caudate nucleus and putamen) are segregated in three territories: associative, sensorimotor and limbic. Striatal interneurons are in part responsible for the integration of these different types of information. Among them, GABAergic interneurons are the most abundant, and can be sorted in three populations according to their content in the calcium binding proteins calretinin (CR), parvalbumin (PV) and calbindin (CB). Conversely, striatal dopaminergic cells (whose role as interneurons is still unclear) are scarce. This study aims to analyze the interneuron distribution in the striatal functional territories, as well as their organization regarding to the striosomal compartment.

Methodology/Principal Findings

We used immunohistochemical methods to visualize CR, PV, CB and tyrosine hydroxylase (TH) positive striatal neurons. The interneuronal distribution was assessed by stereological methods applied to every striatal functional territory. Considering the four cell groups altogether, their density was higher in the associative (2120±91 cells/mm³) than in the sensorimotor (959±47 cells/mm³) or limbic (633±119 cells/mm³) territories. CB- and TH-immunoreactive(-ir) cells were distributed rather homogeneously in the three striatal territories. However, the density of CR and PV interneurons were more abundant in the associative and sensorimotor striatum, respectively. Regarding to their compartmental organization, CR-ir interneurons were frequently found in the border between compartments in the associative and sensorimotor territories, and CB-ir interneurons abounded at the striosome/matrix border in the sensorimotor domain.

Conclusions/Significance

The present study demonstrates that the architecture of the human striatum in terms of its interneuron composition varies in its three functional territories. Furthermore, our data highlight the importance of CR-ir striatal interneurons in the integration of associative information, and the selective role of PV-ir interneurons in the motor territory. On the other hand, the low density of dopaminergic cells casts doubts about their role in the normal human striatum.

Ubiquitin-proteasome system components are upregulated during intestinal regeneration

The ubiquitin proteasome system (UPS) is the main proteolytic system of cells. Recent evidence suggests that the UPS plays a regulatory role in regeneration processes. Here, we explore the possibility that the UPS is involved during intestinal regeneration of the sea cucumber Holothuria glaberrima. These organisms can regenerate most of their digestive tract following a process of evisceration. Initially, we identified components of H. glaberrima UPS, including sequences for Rpn10, β3, and ubiquitin-RPL40. Predicted proteins from the mRNA sequences showed high degree of conservation that ranged from 60% (Rpn10) to 98% (Ub-RPL40). Microarrays and RT-PCR experiments showed that these genes were upregulated during intestinal regeneration. In addition, we demonstrated expression of alpha 20S proteasome subunits and ubiquitinated proteins during intestinal regeneration and detected them in the epithelium and connective tissue of the regenerating intestine. Finally, the intestinal regeneration was altered in animals treated with MG132, a proteasome inhibitor. These findings support our contention that proteasomes are playing an important role during intestinal regeneration.

Chromogranin A-, serotonin-, synaptophysin- and vascular endothelial growth factor-positive endocrine cells and the prognosis of colorectal cancer: an immunohistochemical and ultrastructural study

BACKGROUND AND AIM

Endocrine differentiation in colorectal adenocarcinoma has been reported but its significance as a prognostic marker remains uncertain. The aim of the present study was to analyze the prognostic significance of endocrine differentiation in colorectal cancer.

METHODS

The presence of endocrine cells (EC) was determined in 137 colorectal cancers using light and electron immunohistochemistry and the immunogold method with chromogranin A, serotonin and synaptophysin. Vascular endothelial growth factor (VEGF) expression in tumor biopsies was also analyzed applying anti-VEGF antibodies.

RESULTS

EC labeled with at least one of the studied markers were detected in 47 (34.3%) primary colorectal cancers (30% chromogranin A-positive, 33% synaptophysin-positive and 18% serotonin-positive). In 23% of tumor biopsies, VEGF-positive EC were also detected. The immunostaining on serial sections showed that some chromogranin A-, synaptophysin- or serotonin-positive EC also contained VEGF immune deposits. By the immunogold method, the presence of VEGF was localized to the granules of EC. Tumors with VEGF-positive EC appeared to have significantly higher vascularization, detected as systematic microvessel density (28.89 vs 15.22 vessels/mm(2), P = 0.044, Mann-Whitney U-test) compared to those without VEGF-positive EC. Ultrastructurally, EC in the tumor tissue displayed some features different from those in the normal colon. The survival analyses revealed that patients with EC in primary tumor tissues had a worse prognosis after surgical therapy than those without endocrine cell differentiation (P < 0.05, log-rank test).

CONCLUSIONS

Endocrine differentiation is not an uncommon event in primary colorectal cancer and it could be a useful marker for a worse prognosis after the surgical therapy. Tumors positive for VEGF and containing VEGF-positive EC have higher vascularization, which probably also contributes to the unfavorable prognosis of patients.

Cholinergic interneurons are differentially distributed in the human striatum

Background

The striatum (caudate nucleus, CN, and putamen, Put) is a group of subcortical nuclei involved in planning and executing voluntary movements as well as in cognitive processes. Its neuronal composition includes projection neurons, which connect the striatum with other structures, and interneurons, whose main roles are maintaining the striatal organization and the regulation of the projection neurons. The unique electrophysiological and functional properties of the cholinergic interneurons give them a crucial modulating function on the overall striatal response.

Methodology/Principle Findings

This study was carried out using stereological methods to examine the volume and density (cells/mm³) of these interneurons, as visualized by choline acetyltransferase (ChAT) immunoreactivity, in the following territories of the CN and Put of nine normal human brains: 1) precommissural head; 2) postcommissural head; 3) body; 4) gyrus and 5) tail of the CN; 6) precommissural and 7) postcommissural Put. The distribution of ChAT interneurons was analyzed with respect to the topographical, functional and chemical territories of the dorsal striatum. The CN was more densely populated by cholinergic neurons than the Put, and their density increased along the anteroposterior axis of the striatum with the CN body having the highest neuronal density. The associative territory of the dorsal striatum was by far the most densely populated. The striosomes of the CN precommissural head and the postcommissural Put contained the greatest number of ChAT-ir interneurons. The intrastriosomal ChAT-ir neurons were abundant on the periphery of the striosomes throughout the striatum.

Conclusions/Significance

All these data reveal that cholinergic interneurons are differentially distributed in the distinct topographical and functional territories of the human dorsal striatum, as well as in its chemical compartments. This heterogeneity may indicate that the posterior aspects of the CN require a special integration of information by interneurons. Interestingly, these striatal regions have been very much left out in functional studies.

Effects of castration on the expression of brain-derived neurotrophic factor (BDNF) in the vas deferens and male accessory genital glands of the rat

Brain-derived neurotrophic factor (BDNF) is a growth factor belonging to the family of neurotrophins. Although neurotrophins in the male genital organs have been well documented, their role in the biology of these organs is far from clear. In particular, little is known about the influence of sex hormones on neurotrophin expression. In the present study, using immunohistochemistry and enzyme-linked immunosorbent assay (ELISA), we investigated the distribution and tissue concentration of BDNF in the vas deferens and accessory male genital glands in normal and castrated rats. The expression of BDNF mRNA was also investigated. In normal rats, BDNF immunoreactivity was localized in the musculature of the vas deferens and vesicular gland and in the fibromuscular stromal cells of the prostate. In the ventral prostatic lobes, BDNF immunoreactivity was localized in basal, secretory and neuroendocrine epithelial cells. Innervating ganglia and nerves were immunoreactive in all the examined tracts. After castration, BDNF immunoreactivity increased in the musculature of the vesicular gland and in the fibromuscular stromal cells of both dorsal and ventral prostatic lobes. BDNF immunoreactivity also increased in the nerves. ELISA and reverse transcription/real-time polymerase chain reaction confirmed the findings of the immunohistochemical study. In the accessory glands, castration induced an increase of both BDNF tissue concentration and mRNA expression. These results suggest that BDNF is expressed in the internal male genital organs of the rat and that its expression is downregulated by androgen hormones. We hypothesize that the observed BDNF increases are related to the castration-induced regression of the sympathetic nerves.

Morphological features, distribution and compartmental organization of the nicotinamide adenine dinucleotide phosphate reduced-diaphorase interneurons in the human striatum

Striatal nicotinamide adenine dinucleotide phosphate reduced-diaphorase (NADPH-d)-positive (+) cells are one of the major classes of striatal interneurons. The present study analyzes their somatodendritic morphology, distribution pattern, and compartmental organization in the caudate nucleus (CN) and putamen (Put) of nine normal human brains. The following striatal territories are examined: 1) the precommissural head of the CN; 2) the postcommissural head of the CN; 3) the body of the CN; 4) the gyrus of the CN; 5) the tail of the CN; 6) the precommissural Put; and 7) the postcommissural Put. Three morphologically distinct types of NADPH-d+ neurons were found in each of these territories. The two most common NADPH-d+ neurons displayed an ovoid or triangular perikaryon from which several thick primary dendrites emerged, although much less numerous, bipolar-shaped NADPH-d+ cells were also observed. The highest density of NADPH-d+ neurons was found in the gyrus of the CN, followed by the body of the CN, tail of the CN, postcommissural head of the CN, postcommissural Put, precommissural head of the CN, and precommissural Put. The matrix was the striatal compartment with the densest NADPH-d+ neuronal population. Some of these cells also occurred in the center and peripheral regions of the striosomes located in the head of the CN and in the Put. In the body and gyrus of the CN, the striosomes were largely devoid of these striatal interneurons. Knowledge of the density and distribution of these interneurons should advance our understanding of the organization of the normal human striatum and help to evaluate the effects of neurodegenerative processes on cell density.

Identification of genes involved in estrogenic action in the human prostate using microarray analysis

Estrogens have profound effects on the developing prostate and are suspected to contribute to the development of benign prostatic hyperplasia, but the mechanism by which this hormone elicits its regulatory function still remains largely unknown. Using complementary RNA microarrays comprising approximately 10,000 oligonucleotide gene targets we compared differences in mRNA expression of estradiol-treated and untreated prostatic stromal cells in vitro. Based on a threshold of greater than twofold change, 228, 241, and 464 of the expressed genes were found to be regulated by estradiol after 10, 24, and 48 h of treatment, respectively. The secondary analysis of one estradiol-activated transcript, namely lipopolysaccharide-binding protein, and four estradiol-repressed genes, namely ras homolog gene family member E (RhoE/Rnd3), ubiquitin thiolesterase, interleukin 6, and interleukin 8 (IL-8), by real-time quantitative PCR confirmed the results of the microarray analysis. Moreover, IL-8 and RhoE were found to be down-regulated by estradiol at the protein level as well. We identified a set of genes involved in a wide range of cellular functions that are potentially important for understanding the molecular basis of estradiol action in the prostate.

The diffuse endocrine system: from embryogenesis to carcinogenesis

In the present review we will summarise the current knowledge about the cells comprising the Diffuse Endocrine System (DES) in mammalian organs. We will describe the morphological, histochemical and functional traits of these cells in three major systems gastrointestinal, respiratory and prostatic. We will also focus on some aspects of their ontogeny and differentiation, as well as to their relevance in carcinogenesis, especially in neuroendocrine tumors. The first chapter describes the characteristics of DES cells and some of their specific biological and biochemical traits. The second chapter deals with DES in the gastrointestinal organs, with special reference to the new data on the differentiation mechanisms that leads to the appearance of endocrine cells from an undifferentiated stem cell. The third chapter is devoted to DES of the respiratory system and some aspects of its biological role, both, during development and adulthood. Neuroendocrine hyperplasia and neuroendocrine lung tumors are also addressed. Finally, the last chapter deals with the prostatic DES, discussing its probable functional role and its relevance in hormone-resistant prostatic carcinomas.

Presence of neuroendocrine cells during postnatal development in rat prostate: Immunohistochemical, molecular, and quantitative study

BACKGROUND

This work was undertaken to study the prostate neuroendocrine cells (PNEC) during the post-natal development of rats.

METHODS

Forty male Wistar rats (pre-pubertals, pubertals, young, and aged adults) were used for immunohistochemistry of chromogranin A (cgA), serotonin (SER), and protein gene product 9.5 (PGP9.5). They were also evaluated for numerical cell density (NV SER) and PNEC number per prostate (N SER). Five additional young adult rats were used for a RT-PCR study (mRNA cgA detection).

RESULTS

Weak immunoreactivity to cgA was observed in pubertal rats. No PNEC immunostained to PGP 9.5 was observed. Cells expressing SER were detected in all the groups exclusively located in periurethral ducts. The NV SER increased significantly in pubertal animals. In aged animals, it decreased to levels observed in pre-pubertal rats. The N SER increased significantly from pre-pubertal to young adults, decreasing in aged adults. There was weak production of cgA mRNA, with more expression in the dorsal prostate.

CONCLUSIONS

PNEC differ in rats when compared to humans: they are weakly immunopositive to cgA, do not express PGP 9.5, only show immunoreactivity to SER, and do not appear in acini. The changes in the amount of rat PNEC during the post-natal development suggest an androgenic influx. PNEC might regulate the contractility of periurethral ducts.

Stereologic estimation of the number of neuroendocrine cells in normal human prostate detected by immunohistochemistry

Neuroendocrine cells may play a role in both normal and pathologic conditions of the human prostate. It may be interesting to investigate 1) whether there are significant amounts of neuroendocrine cells in human adult normal prostate, and 2) whether the distribution of these cells shows regional differences. This study estimates both absolute and relative amounts of neuroendocrine cells immunostained for two neuronal markers (chromogranin A and protein gene product 9.5) and for serotonin in the three regions of human prostate, transition zone, central zone, and peripheral zone, using unbiased stereologic measurements. There was observed a predominance of neuroendocrine cells in the transition zone of the normal prostate. The neuroendocrine cells of this region may play a role in the genesis of benign prostate hyperplasia. The significant presence of neuroendocrine cells secreting neuropeptides in peripheral zone could be correlated with the induction of androgen-independent growth in prostate carcinogenesis. The wolffian origin attributed to the central zone can explain its poor population of neuroendocrine cells.

Ribozyme-targeting of a secreted FGF-binding protein (FGF-BP) inhibits proliferation of prostate cancer cells in vitro and in vivo

Prostate cancer is one of the most common malignant tumors with increasing incidence rates in the aging male. Since locally advanced or metastatic prostate tumors are essentially incurable, identification of new target molecules and treatment strategies is of critical importance. Fibroblast growth factor-2 (FGF-2) acts as potent mitogen which is upregulated in prostate cancers modulating cancer cell proliferation and development of an invasive phenotype. Normally it is tightly bound to the extracellular matrix that quenches its biological activity. The FGF-binding proteins (FGF-BP, HBp17) is a secreted protein which is able to mobilize and activate FGF-2 from the extracellular matrix. Here we show that FGF-BP is highly expressed in prostate tumor cells. To study the functional role of FGF-BP, we use a ribozyme-targeting approach to selectively deplete FGF-BP in prostate cancer cells achieving a more than 50% reduction of FGF-BP mRNA and protein levels in two mass-transfected cell lines. FGF-BP depletion reduces proliferation of the cells in vitro without changes in cell cycle distribution or apoptosis. Using cDNA microarrays, Northern blotting and RT-PCR, we show a complex pattern of changes in the gene expression profiles upon FGF-BP depletion. Most strikingly, ribozyme-mediated reduction of FGF-BP levels completely abolishes the ability of the highly metastatic PC-3 prostate carcinoma cells to grow tumors in an athymic nude mouse in vivo model which is far beyond the effects of FGF-BP ribozyme targeting observed previously in cells from other tumors in the same model. Taken together, our study identifies FGF-BP as a potential rate-limiting factor for prostate cancer growth and, due to its restricted expression pattern in adults, a potentially attractive target for prostate cancer therapy.

Cholinergic innervation and function in the prostate gland

The mammalian prostate is densely innervated by hypogastric and pelvic nerves that play an important role in regulating the growth and function of the gland. While there has been much interest in the role of the noradrenergic innervation and adrenoceptors in prostate function, the role of cholinergic neurones in prostate physiology and pathophysiology is not well understood. This review focuses on the role of acetylcholine and cholinoceptors in prostate function. Nitric oxide, vasoactive intestinal polypeptide, and/or neuropeptide Y are co-localised with cholinesterase and/or acetylcholine transporter in some of the nerve fibres supplying the prostate. Their roles are also briefly discussed in this review. A dense network of cholinesterase-staining fibres supplies both prostate epithelium and stroma, suggesting a role of acetylcholine and/or co-localised neuropeptides in the modulation of prostatic secretions, as well as smooth muscle tone. A predominantly epithelial location for prostate muscarinic receptors indicated a major secretomotor role for acetylcholine. The muscarinic receptor subtype mediating muscarinic agonist-induced smooth muscle contraction or enhancement of contractions evoked by nerve stimulation differs in different species. In the human, there is evidence for M(1) receptors on the epithelium, M(2) receptors on the stroma, and both M(1) and M(3) receptors in some prostate cancer cell lines. Several recent investigations indicate that muscarinic receptors may also mediate or modulate normal, benign, and malignant prostate growth. The role of muscarinic agonists and their receptors and the influences of age, testicular, and other steroids in regulating the effects are reviewed.