Search

Aims: Stromal growth is critical for prostate enlargement during benign prostatic hyperplasia (BPH). While responses of prostate cells to single growth factors have been well characterized, responses to multiple growth factors at once are poorly understood. Here, we examined the effects of combinations between epidermal growth factor (EGF), fibroblast growth factor (FGF), and transforming growth factor-β1 (TGF-β1) in human prostate stromal cells., Main Methods: EGF, FGF, and TGF-β1 were applied to WPMY-1 cells, an immortalized, non-malignant line of stromal cells from the human prostate. Hypertrophic responses were assessed by protein/DNA ratio, and cyclin D1 mRNA by RT-PCR. Expression of EGF, FGF, and TGF-β1 and their receptors in human prostate tissue was analyzed by RT-PCR, Western blot, and fluorescence staining., Key Findings: Hypertrophic responses to single growth factors and combinations were similar. Combinations showed additive effects on cyclin D1 mRNA. Combination of EGF with TGF-β1, but not EGF or TGF-β1 alone, caused assembly of cells to a new two-dimensional structure, being characterized by dense aggregates connected by branches of few cells. EGF and TGF-β1 were detected together in human prostates. Receptors for EGF and TGF-β colocalized on stromal cells in human prostates., Significance: Responses of prostate stromal cells to combinations of EGF, FGF, and TGF-β1 may be quantitatively different, qualitatively different, or similar to responses to single growth factors. The combination of EGF and TGF-β1, but not EGF or TGF-β1 alone, induces aggregation of prostate stromal cells, which may be relevant for morphogenesis., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Smooth muscle contraction may be critical for lower urinary tract symptoms (LUTS) in patients with benign prostate hyperplasia and requires stable anchorage of the cytoskeleton to the cell membrane. These connections are regulated by focal adhesion kinase (FAK). Here, we addressed the involvement of FAK in the regulation of smooth muscle contraction in hyperplastic human prostate tissues. Prostate tissues were obtained from radical prostatectomy. Expression of FAK and focal adhesion proteins was assessed by Western blot analysis and immunohistochemical stainings. Effects of the FAK inhibitors PF-573228 and Y-11 on contraction of prostate strips were examined in the organ bath. Expression of FAK and focal adhesion proteins (integrin-5α, paxilin, and c-Src) was detected by Western blot analysis in prostate samples. By double immunofluorescence staining with calponin and pan-cytokeratin, expression of FAK was observed in stromal and epithelial cells. Immunoreactivity for FAK colocalized with integrin-5α, paxilin, talin, and c-Src. Stimulation of prostate tissues with the α1-adrenergic agonist phenylephrine increased the phosphorylation state of FAK at Tyr³⁹⁷ and Tyr⁹²⁵ with different kinetics, which was blocked by the α1-adrenoceptor antagonist tamsulosin. Norepinephrine and phenylephrine induced concentration-dependent contractions of prostate strips. Both FAK inhibitors PF-573228 and Y-11 significantly inhibited norepinephrine- and phenylephrine-induced contractions. Finally, PF-573228 and Y-11 inhibited contractions induced by electric field stimulation, which was significant at the highest frequency. In conclusion, α1-adrenergic smooth muscle contraction or its regulation involves FAK in the human prostate. Consequently, FAK may be involved in the pathophysiology of LUTS and in current or future LUTS therapies., (Copyright © 2014 the American Physiological Society.)

Purpose: Smooth muscle contraction and prostate growth are important targets for medical therapy of lower urinary tract symptoms (LUTS) in patients with benign prostatic hyperplasia. Honokiol and Magnolol are lignan constituents of Magnolia species, which are used in traditional Asian medicine. Here, we examined effects of honokiol and magnolol on contraction of human prostate tissue and on growth of stromal cells., Methods: Prostate tissues were obtained from radical prostatectomy. Contraction of prostate strips was examined in organ bath studies. Effects in stromal cells were assessed in cultured immortalized human prostate stromal cells (WPMY-1). Ki-67 mRNA was assessed by reverse transcription-polymerase chain reaction, and proliferation by a fluorescence 5-ethynyl-2'-deoxyuridine assay., Results: Honokiol (100μM) reduced noradrenaline-induced contractions, which was significant at 10 to 100μM noradrenaline. Honokiol reduced phenylephrine-induced contractions, which was significant at 3 to 100μM phenylephrine. Honokiol reduced electric field stimulation-induced contractions very slightly. In WPMY-1 cells, honokiol (24 hours) induced cell death. Magnolol (100μM) was without effects on contraction, and cellular viability., Conclusions: Honokiol inhibits smooth muscle contraction in the human prostate, and induces cell death in cultured stromal cells. Because prostate smooth muscle tone and prostate growth may cause LUTS, it appears possible that honokiol improves voiding symptoms.

Inhibition of prostate smooth muscle contraction is an important strategy for medical treatment of lower urinary tract symptoms (LUTS). Besides α1-adrenoceptors, prostate smooth muscle contraction is induced by activation of thromboxane (TXA2) receptors (TXA2-R). Here, we examined the effects of the TXA2-R antagonist picotamide on contraction of human prostate tissue. Prostate tissues were obtained from radical prostatectomy. The effects of picotamide (300 μM), L-665,240 (3 μM), and seratrodast (3 μM) on U46619-, electric field stimulation- (EFS-), phenylephrine-, and norepinephrine-induced contractions were studied in organ baths. Expression of TXA2-R and TXA2 synthase (TXS) was examined by fluorescence stainings. Picotamide, seratrodast, and L-655,240 inhibited concentration-dependent contractions induced by the TXA2 analog U46619. Picotamide, but not seratrodast or L-655,240, inhibited frequency-dependent contractions induced by EFS. Picotamide inhibited concentration-dependent contractions induced by norepinephrine or by the selective α1-adrenoceptor agonist phenylephrine. In prostate strips, where only submaximal contraction by a low dose of phenylephrine was induced, application of U46619 raised tone to maximum phenylephrine-induced tension. Immunoreactivity for TXA2-R and TXS was observed in the stroma and in epithelial cells of glands. Colocalization of both immunoreactivites was observed with the smooth muscle markers calponin and α-smooth muscle actin, with the epithelial marker pan-cytokeratin, and with prostate-specific antigen in the stroma and glands. The receptor antagonist picotamide inhibits α1-adrenergic, TXA2-mediated, and EFS-induced contractions in the human prostate. To the best of our knowledge, this is the first antagonist able to inhibit two different contraction systems in the prostate.

Purpose: Phosphodiesterase type 5 inhibitors were recently introduced as a new treatment option for men with lower urinary tract symptoms. Safety and clinical effectiveness are well documented but the mode of action is still unclear. We determined and compared the expression of phosphodiesterase type 5 in the spinal cord of normal (sham operated) rats and rats with partial urethral obstruction induced bladder overactivity. We also assessed the urodynamic effects of intravenously and intrathecally administered sildenafil in the rats to determine whether phosphodiesterase type 5 inhibitors exert effects on the sacral spinal cord., Materials and Methods: A total of 65 male Sprague-Dawley rats were used for molecular/morphological and functional experiments. Bladder overactivity was induced via surgical partial urethral obstruction in 39 of 65 rats. Spinal phosphodiesterase type 5 expression was assessed by histology and polymerase chain reaction. The effects of sildenafil administered intravenously or intrathecally were studied urodynamically., Results: Phosphodiesterase type 5 was expressed in various regions of the lumbosacral spinal cord, including the sacral regions of micturition control. Expression was similar in normal rats and rats with partial urethral obstruction/bladder overactivity. In normal rats intravenous and intrathecal sildenafil had no urodynamic effect. When administered intravenously and intrathecally to rats with partial urethral obstruction/bladder overactivity, sildenafil decreased micturition frequency and bladder pressure. Doses tested intrathecally had no effect when given intravenously., Conclusions: Phosphodiesterase type 5 is expressed in the rat spinal cord. Intravenous sildenafil may exert part of its urodynamic effect in rats with partial urethral obstruction/bladder overactivity via an effect on the sacral spinal cord., (Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Objectives: To determine accuracy of upper tract cytology and ureteroscopic biopsy according to the 2004 World Health Organization (WHO) classification in predicting the correct tumor grade in patients with urothelial cancer of the upper urinary tract (UUT-UC)., Methods: Pathology reports of 77 nephroureterectomy specimens were retrospectively analyzed for tumor grade and compared with preoperatively gained cytology and ureteroscopic biopsy results. For analysis, the 2004 WHO classification was used., Results: Overall sensitivity of cytology and biopsy in diagnosis of UUT-UC was 64% and 74%, respectively. Accuracy of cytology and biopsy in predicting high grade cancer was 53% and 58%, respectively. Combination of cytology and biopsy could improve sensitivity (84%) and accuracy (68%), but even for this combination, 15% of high grade tumors were misinterpreted as low grade cancer., Conclusion: Our results show only limited accuracy for preoperative cytology and ureterorenoscopically performed biopsies in the prediction of the correct tumor grading of an UUT-UC. Therefore, we suggest the use of additional diagnostic procedures before the decision for definitive surgical treatment in patients with UUT-UC is made., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: Prostate smooth muscle tone is regulated by α1-adrenoceptor-induced contraction and cAMP-mediated relaxation. EPAC is an effector of cAMP, being involved in smooth muscle relaxation and cell cycle control outside the lower urinary tract. Here, we investigated the expression and function of EPAC in human prostate tissues from patients undergoing radical prostatectomy., Results: mRNA and protein expression of EPAC was detected in all prostate tissues by RT-PCR and Western blot analysis. Immunoreactivity was observed in stromal cells, and colocalized with immunofluorescence for α-smooth muscle actin and calponin. Under normal conditions, noradrenaline- or phenylephrine-induced contraction of prostate strips in the organ bath was not affected by the EPAC activator pCPT (SP-8-pCPT-2'-O-Me-cAMPS.NA) (30 μM). However, when the cyclooxygenase inhibitor indomethacin (50 μM) was added, EPAC activators pCPT and OME (8-CPT-2'-O-Me-cAMP.Na) (30 μM) significantly reduced contractions by low concentrations of phenylephrine. These effects were not observed on noradrenaline-induced contraction. OME and pCPT caused phosphorylation of the transcription factor Elk1 in prostate tissues. Elk1 activation was confirmed by EMSA (electrophoretic mobility shift assay), where OME and pCPT incresed Elk1 binding to a specific DNA probe., Conclusions: EPAC activation may reduce α1-adrenergic prostate contraction in the human prostate, although this effect is masked by cyclooxygenases and β-adrenoceptors. A main EPAC function in the human prostate may be the regulation of the transcription factor Elk1.

Introduction: Benign prostatic hyperplasia (BPH) is a highly prevalent disease in the aging male and significantly impairs quality of life. Men with BPH present with lower urinary tract symptoms (LUTS), which include storage and voiding disorders. Medical therapy is the first option in patients with mild to moderate symptoms., Areas Covered: α1-adrenoceptor antagonists, 5α-reductase inhibitors or the combination of both have been considered gold standard for pharmacological treatment over the last decade in this patient cohort. Recently, a variety of novel substances have been tested which include Phosphodiesterase Typ 5 inhibitors (PDE5i), anti-cholinergic agents and β-3-agonists. This article highlights the key studies with regard to each drug class and discusses current pharmacotherapy and possible future treatment options., Expert Opinion: In patients with small prostates, α1-adrenoceptor antagonists represent the gold standard in the medical treatment of mild LUTS. For men with large prostate glands and mild to moderate LUTS, recent data support the combination of α1-adrenoceptor antagonists and 5α-reductase inhibitors. PDE5i may be useful in men with LUTS and concomitant erectile dysfunction, while anti-cholinergics have been shown to be beneficial in patients with predominant storage disorders. Future studies have to elucidate the role of β-3-agonists in men with BPH and LUTS.

Background: Binding of clathrins or caveolin to G protein-coupled receptors may induce post-translational modifications of receptor function. Receptor regulation by clathrin requires cofactors ADP-ribosylation factor 6 (ARF6) and adaptin, while dynamin is required for clathrin- and caveolin-dependent mechanisms., Objective: To investigate the expression and α1-adrenoceptor binding of clathrins, caveolin, and their cofactors in the human prostate., Methods: Prostate tissue was obtained from radical prostatectomy. Expression of clathrin heavy chain (HC), clathrin light chain A and B (LCA, LCB), caveolin-1, ARF6, β-adaptin, and dynamin-2 was studied by RT-PCR, Western blot, immunohistochemistry, and fluorescence staining. Interaction of α1A-adrenoceptors with clathrins and caveolin-1 was studied by coimmunoprecipitation., Results: mRNA and protein expression of clathrin HC, LCA, LCB, caveolin-1, dynamin-2, and β-adaptin was detected in prostate tissues of each patient. Immunohistochemistry demonstrated the expression of clathrin HC, LCA, LCB, caveolin, dynamin, and β-adaptin in stromal cells. Immunoreactivity for these proteins colocalized with α-smooth muscle actin and α1A-adrenoceptors in double fluorescence staining. Coimmunoprecipitation demonstrated that α1A-adrenoceptors in prostate tissue interact with clathrin HC and LCB under resting conditions, but not with caveolin-1. Stimulation of prostate tissues with noradrenaline (30 µM) in vitro induced binding of clathrin LCA to α1A-adrenoceptors., Conclusions: The prostatic α1-adrenoceptor population is at least partially bound to clathrin HC and LCB. Upon receptor activation, prostate α1A-adrenoceptors bind clathrin LCA. This points to a new concept of post-translational α1-adrenoceptor regulation in the prostate, which includes receptor interaction with accessory binding partners., (Copyright © 2013 Wiley Periodicals, Inc.)

Background: Information on autonomic neurapraxia in female urogenital surgery is scarce, and a model to study it is not available., Objective: To develop a model to study the impact of autonomic neurapraxia on bladder function in female rats, as well as to assess the effects of corticosteroid therapy on the recovery of bladder function in this model., Design, Setting, and Participants: Female Sprague-Dawley rats were subjected to bilateral pelvic nerve crush (PNC) and perioperatively treated with betamethasone or vehicle. Bladder function and morphology of bladder tissue were evaluated and compared with sham-operated rats., Outcome Measurements and Statistical Analysis: Western blot, immunohistochemistry, organ bath experiments, and cystometry., Results and Limitations: Sham-operated rats exhibited regular micturitions without nonvoiding contractions (NVCs). Crush of all nerve branches of the pelvic plexus or PNC resulted in overflow incontinence and/or NVCs. Betamethasone treatment improved recovery of regular micturitions (87.5% compared with 27% for vehicle; p<0.05), reduced lowest bladder pressure (8 ± 2 cm H(2)O compared with 21 ± 5 cm H(2)O for vehicle; p<0.05), and reduced the amplitude of NVCs but had no effect on NVC frequency in PNC rats. Compared with vehicle, betamethasone-treated PNC rats had less CD68 (a macrophage marker) in the pelvic plexus and bladder tissue. Isolated bladder from betamethasone-treated PNC rats exhibited better nerve-induced contractions, contained more cholinergic and sensory nerves, and expressed lower amounts of collagen III than bladder tissue from vehicle-treated rats., Conclusions: PNC causes autonomic neurapraxia and functional and morphologic changes of isolated bladder tissue that can be recorded as bladder dysfunction during awake cystometry in female rats. Perioperative systemic betamethasone treatment reduced macrophage contents of the pelvic plexus and bladder, partially counteracted changes in the bladder tissue, and had protective effects on micturition function., (Copyright © 2012. Published by Elsevier B.V.)

Aims: Besides their role in contraction, α1-adrenoceptors may be involved in prostate hyperplasia. This would require receptor signaling by growth-promoting pathways. Akt (syn. Protein kinase B) is an important regulator of growth and differentiation., Objective: To investigate whether α1-adrenoceptors in the human prostate activate Akt., Main Methods: Prostate tissue was obtained from patients undergoing radical prostatectomy. Akt expression was investigated by RT-PCR, Western blot, and immunohistochemistry. Akt activation by noradrenaline (30 μM) and phenylephrine (10 μM) was assessed by Western blot analyses with a phospho-specific antibody. The effects of the Akt inhibitors FPA-124 and 10-DEBC on phenylephrine-, noradrenaline- and electric field stimulation- (EFS-) induced contraction were studied in myographic measurements., Key Findings: mRNA of all three Akt isoforms (Akt1, Akt2, Akt3) was detected by RT-PCR in all prostate samples (n=6 patients). Protein expression was confirmed by Western blot analysis (n=8 patients). Immunohistochemical staining for Akt revealed strong immunoreactivity in prostate smooth muscle cells (n=5 patients). Stimulation of prostate tissues with noradrenaline (30 μM, n=8 patients) or phenylephrine (10 μM, n=7 patients) caused significant Akt phosphorylation at serine-473, indicating activation of Akt. FPA124 and 10-DEBC were without effects on noradrenaline-, phenylephrine-, or EFS-induced contraction of prostate strips., Significance: Prostate α1-adrenoceptors activate Akt. Consequently, Akt is a target of α1-blocker therapy, which has been unknown to date. Our findings point to functions of prostate α1-adrenoceptors besides contraction., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Cannabinoid receptor (CB)-mediated functions may be involved in the regulation of bladder function, but information on endocannabinoid signals during micturition is scarce., Objective: Investigate the expression of the endocannabinoid-degrading enzyme fatty acid amide hydrolase (FAAH) in human, rat, and mouse bladders and study the effects of inhibition of FAAH during urodynamics in awake rats., Design, Setting, and Participants: Bladder tissue from humans, mice, and rats was used for measurements. Female Sprague-Dawley rats were administered the FAAH inhibitor oleoyl ethyl amide (OEtA) or vehicle intravenously (IV) or intravesically (IVES) with or without rimonabant (CB1 antagonist) or SR144528 (CB2 antagonist)., Measurements: Real-time transcriptase-polymerase chain reaction, Western blot, immunohistochemistry, and cystometry in awake rats., Results and Limitations: Messenger RNA and protein for FAAH was expressed in the mucosa of human, mouse, and rat urinary bladders. Immunoreactivities for FAAH and CB2 were codistributed in rat and human urothelium. IV OEtA (0.3mg/kg) to rats increased intercontraction intervals (ICIs), micturition volume (MV), bladder capacity (BC), and threshold pressure (TP) by 17±1%, 16±1%, 17±1%, and 19±5%, respectively (all p<0.05 vs baseline). IVES OEtA (1 and 10mg/l) in rats dose-dependently increased (p<0.05 vs baseline) ICI (19±2% and 35±5%), MV (15±3% and 32±4%), BC (16±2% and 34±4%), and TP (15±1%, 21±3%). SR144528 (IVES 5mg/l) abolished all effects of OEtA, whereas rimonabant only counteracted effects of OEtA on TP., Conclusions: Bladder mucosa of all species expressed FAAH. Rat and human urothelium coexpressed FAAH and CB2. The FAAH inhibitor OEtA altered urodynamic parameters that reflect sensory functions of micturition in rats. Suggesting a role for the endocannabinoid system in bladder mechanoafferent functions of rats, effects of IVES OEtA were abolished by an IVES CB2 antagonist and partly counteracted by an IVES CB1 antagonist., (Copyright © 2011 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Objective: To investigate whether 1-adrenoceptor signaling in the human prostate involves regulation of the mitogen-activated protein kinase (MAPK) p38. Although α1-adrenoceptors are an important target for therapy of lower urinary tract symptoms in patients with prostate hyperplasia, intracellular signaling by prostate α1-adrenoceptors is not sufficiently understood., Methods: Prostate tissue was obtained from patients undergoing radical prostatectomy. The effect of phenylephrine (10 μM) on p38 activity was assessed by Western blot analysis with a phospho-specific antibody. Expression of p38 was studied by immunohistochemistry and immunofluorescence staining. The effect of the p38 inhibitor SB 202190 (10 μM) on phenylephrine-induced contraction was studied in myographic measurements., Results: Stimulation of human prostate tissue with phenylephrine resulted in reduced threonine180/tyrosine182 phosphorylation of p38, indicating deactivation of p38 (P = .039 after 5 minutes). Immunohistochemical staining demonstrated expression of p38 in stromal cells of human prostate tissue. Immunofluorescence staining identified these cells as smooth muscle cells, as p38 colocalized with immunoreactivity for α-smooth muscle actin. The p38 inhibitor SB 202190 was without effect on phenylephrine-induced contraction., Conclusion: Using intact human prostate tissue, we herewith describe a new signal transduction pathway of prostate α1-adrenoceptors. In addition to mediating contraction, prostate α1-adrenoceptors induce intracellular signaling, which results in deactivation of p38 MAPK. This is not involved in α1-adrenergic contraction, and points to α1-adrenoceptor functions beyond contraction., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Objective: • To test whether β1-adrenoceptor activation leads to phosphorylation of the β2-adrenoceptor in human prostate tissue., Patients and Methods: • Prostate tissue from patients undergoing radical prostatectomy was stimulated in vitro with the α1-adrenergic agonist phenylephrine (10 µM). • α2-adrenoceptor phosphorylation at serines 345/346 was studied using Western blot analysis with a phospho-specific antibody. • The role of second messenger kinases was assessed by studying the effects of the protein kinase C (PKC) inhibitor Ro 31-8425 and the protein kinase A (PKA) inhibitor H89 on phenylephrine-induced phosphorylation. • The expression of G protein-coupled receptor kinases (GRKs) 2/3 was analysed using quantitative reverse-transcriptase-polymerase chain reaction (RT-PCR), Western blot analysis and immunohistochemistry., Results: • Stimulation of prostate tissue with phenylephrine resulted in phosphorylation of the β2-adrenoceptor (5, 10 and 20 min after stimulation). • This α1-adrenoceptor-induced phosphorylation of β2-adrenoceptors was resistant to inhibition of PKC and PKA. • Changes in phosphorylation levels were not attributable to changes in receptor levels, as these remained constant during stimulation. • RT-PCR and Western blot analysis showed expression of GRK2/3 in human prostate tissues. • Immunohistochemical staining showed that GRK2/3 expression in human prostate tissue is located to stromal and smooth muscle cells., Conclusions: • Activation of α1-adrenoceptors causes phosphorylation of β2-adrenoceptors in the human prostate. This may enhance α1-adrenergic contraction and is possibly mediated by GRK2, which is expressed in prostate smooth muscle. • Mutual regulation between different adrenergic receptors might be involved in the therapeutic effects of α1-blockers in patients with benign prostate hyperplasia., (© 2010 THE AUTHORS. BJU INTERNATIONAL © 2010 BJU INTERNATIONAL.)

Unlabelled: The aim of the study was to define the learning curve of a single cytologist as a limitation of urinary cytology. A total of 1034 cytologic and histologic findings of patients undergoing transurethral resection of the bladder for suspicion of bladder cancer were reviewed, and cytologic evaluations of a single cytologist from the beginning of his learning period were compared with the results of a cytologist at a national reference center. Our results showed that the individual learning curve has a significant impact on the quality of urine cytology., Background: To define the learning curve of a single cytologist as a limitation of urinary cytology and to compare his results with a reference center for urinary cytology., Patients and Methods: Cytologic and histologic findings of patients undergoing transurethral resection of the bladder for suspicion of bladder cancer were reviewed. Cytologic evaluations from a single local cytologist during his learning period and of a cytologist of a national reference center were compared. Changes of sensitivity and specificity of cytology from the local cytologist over the time period were assessed. Differences were estimated by using kappa statistics., Results: The local cytologist evaluated 1034 cytologic findings. Sensitivity and specificity of cytology estimated by the local cytologist were 86% and 66% at the beginning of the learning period, but 68% and 84% at the end of it (P ≤ .05). In high-grade carcinomas, sensitivity did not decrease over the years (P > .05). In contrast, the sensitivity in the diagnosis of low-grade tumors decreased from 86% to 56% (P ≤ .05). The reference center estimated a constant sensitivity and specificity of 59% and 97%, respectively. Agreement of findings between local and national cytologists increased significantly over the learning period (P < .05)., Conclusion: The individual learning curve has a significant impact on the quality of urinary cytology. Both specificity of cytology and sensitivity for low-grade tumors changed significantly when done by a local cytologist at the beginning of learning period. These findings emphasize the impact of the individual learning curve on the clinical value of urinary cytology in diagnosis of bladder cancer., (Copyright © 2011. Published by Elsevier Inc.)

Purpose: Alpha1A-adrenoceptors are important regulators of prostatic smooth muscle tone and an important target for therapy of lower urinary tract symptoms. The function of heptahelical transmembrane receptors such as adrenoceptors can be regulated by β-arrestin-2, which may bind to receptors besides G proteins. Here, we investigated the expression and α1A-adrenoceptor binding of β-arrestin-2 in the human prostate., Methods: Human prostatic tissues were obtained from patients undergoing radical prostatectomies. The expression of β-arrestin-2 and α1A-adrenoceptors was studied by RT-PCR, Western blot analysis, and immunohistochemistry. The protein-protein interaction between α1A-adrenoceptors and β-arrestin-2 was investigated by coimmunoprecipitation., Results: RT-PCR and Western blot analysis demonstrated the expression of β-arrestin-2 mRNA and protein in the human prostate. Immunohistochemistry demonstrated β-arrestin-2 expression in smooth muscle and stromal cells. Coimmunoprecipitation studies demonstrated that α1A-adrenoceptors in the human prostate may interact with β-arrestin-2. Thus, specific binding of β-arrestin-2 to α1A-adrenoceptors was significantly higher than background during α1A-adrenoceptor detection in β-arrestin-2 precipitates (P < 0.001) or during β-arrestin-2 detection in α1A-adrenoceptor precipitates (P < 0.005). This interaction may be located to prostate smooth muscle cells, as expression of the α1A-adrenoceptor was exclusively found in smooth muscle cells after immunohistochemical staining., Conclusion: With β-arrestin-2, we identified a new binding partner of the α1A-adrenoceptor in human prostate smooth muscle. Binding of β-arrestin-2 may be involved in posttranslational regulation of prostate α1A-adrenoceptors.

Thromboxane A(2) (TXA(2)) induces contraction in different smooth muscle types via its receptor (TXA(2) receptor). However, any motoric role of TXA(2) in prostate smooth muscle tone has not been studied to date. Here, we investigated whether TXA(2) induces contraction of human prostate tissue. After ethical approval, prostate tissue was obtained from 47 patients undergoing radical prostatectomy. Effects of the TXA(2) analogue U46619 ((5Z)-7-[(1R,4S,5S,6R)-6-[(1E,3S)-3-hydroxy-1-octenyl]-2-oxabicyclo[2.2.1]hept-5-yl]-5-heptonic acid) in isolated human prostate strips were studied in organ bath experiments with or without the Rho kinase inhibitor, Y27632 (trans-4-[(1R)-1-aminoethyl]-N-4-pyridinylcyclohexanecarboxamide dihydrochloride), or the calmodulin antagonist W7 (N-(6-aminohexyl)-5-chloro-1-naphtalenesulfonamide hydrochloride). Expression of TXA(2) synthase and TXA(2) receptors were examined by Western blot analysis and immunohistochemistry. Endogenous TXA(2) was quantified by enzyme immunoassay. U46619 induced concentration-dependent contractions of human prostate strips, with a maximum contraction at 3 μM. U46619-induced prostate contraction was significantly inhibited by Y27632 (30 μM) and by W7 (100 μM). TXA(2) synthase and TXA(2) receptors were detected by Western blot analysis. Immunohistochemical stainings showed that expression of TXA(2) synthase in prostate tissue was located to glandular cells, while prostate TXA(2) receptors were located to smooth muscle and glandular cells. The stable TXA(2) metabolite TXB(2) was detected by enzyme immunoassay in the prostate. TXA(2) induces contraction of isolated human prostate tissue by TXA(2) receptor activation. Prostate smooth muscle TXA(2) receptors are coupled to Rho kinase and Ca(2+)-dependent mechanisms. The distribution of TXA(2) synthase and TXA(2) receptors in the human prostate suggests TXA(2)-mediated paracrine epithelial-stromal interactions., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Introduction: α1-Adrenoceptors are considered critical for the regulation of prostatic smooth muscle tone. However, previous studies suggested further α1-adrenoceptor functions besides contraction. Here, we investigated whether α1-adrenoceptors in the human prostate may activate extracellular signal-regulated kinases (ERK1/2)., Methods: Prostate tissues from patients undergoing radical prostatectomy were stimulated in vitro. Activation of ERK1/2 was assessed by Western blot analysis. Expression of ERK1/2 was studied by immunohistochemistry. The effect of ERK1/2 inhibition by U0126 on phenylephrine-induced contraction was studied in organ-bath experiments., Results: Stimulation of human prostate tissue with noradrenaline (30 μM) or phenylephrine (10 μM) resulted in ERK activation. This was reflected by increased levels of phosphorylated ERK1/2. Expression of ERK1/2 in the prostate was observed in smooth muscle cells. Incubation of prostate tissue with U0126 (30 μM) resulted in ERK1/2 inhibition. Dose-dependent phenylephrine-induced contraction of prostate tissue was not modulated by U0126., Conclusions: α1-Adrenoceptors in the human prostate are coupled to ERK1/2. This may partially explain previous observations suggesting a role of α1-adrenoceptors in the regulation of prostate growth., (Copyright © 2011 S. Karger AG, Basel.)

Objective: to determine the influence of the knowledge of the endoscopic findings and the influence of the patient's history on the cytologist's judgement, as urinary cytology is known to be subjective and has several limitations, in particular a high inter- and intra-observer variability., Patients and Methods: we analysed the cytological and histological findings of patients who underwent transurethral resection of a bladder tumour, and determined whether the cytologist was aware of the endoscopic findings or not. The sensitivity and specificity of cytology were calculated with or without this knowledge, and that of the patients' bladder cancer history., Results: the findings of 1705 patients were reviewed; in 641 the histological examination confirmed a malignant tumour and 1046 were classified as benign. The sensitivity of cytology was 66.0% and the specificity was 78.4%. The cytologist was aware of the endoscopic finding and patient history in 742 cases, and unaware of the endoscopic findings in 963. The specificity was higher in the latter group (80.2% vs 73.0%; P= 0.006). The specificity in patients with the endoscopic findings described as 'negative', 'inflammation', 'scar tissue', 'flat lesion', 'suspicious for tumour', and 'exophytic tumour' was 89.8%, 89.9%, 85.0%, 77.1%, 63.2% and 48.6%, respectively (P < 0.001). In 898 patients the history was negative for bladder tumours. Among these patients the sensitivity and specificity of cytology was 67.3% and 79.7%; the sensitivity and specificity was 65.4% and 74.8% for the 807 patients with a positive history of bladder cancer (P= 0.054)., Conclusion: both being aware of the endoscopic findings and a positive patient history for bladder cancer lowers the specificity of cytology. Consequently, the cytologist should be unaware of the endoscopic findings.

Objectives: To assess whether the use of fluorescence endoscopy (FE) decreases the clinical value of urinary cytology compared with the use of white light endoscopy (WLE)., Methods: The endoscopic, cytologic, and histologic findings of patients who had undergone transurethral resection of the bladder with or without FE were reviewed. The number and characteristics of the tumors that had been overlooked by WLE or FE but detected by cytology were analyzed. An assessment of whether the sensitivity and specificity of urinary cytology changed according to the use of FE or WLE was conducted., Results: The data from 1705 patients were included. Histologic findings were obtained from 238 patients using WLE and from 1467 patients using FE. Histologically confirmed malignancy was found in 641 patients, and the disease of 1064 was classified as benign. FE was superior to WLE in sensitivity in the detection of bladder cancer (94.3% vs 86.3%, P <.05). Cytology detected 53 of 88 tumors that were not detected by WLE (47 high-grade tumors); 31 tumors were overlooked by FE, of which 20 were detected by cytology (12 were high-grade tumors). The sensitivity and specificity of cytology was 66.0% and 78.4%, respectively. The specificity of cytology using WLE and FE was 75% and 79.1% (P >.05) and the sensitivity was 61.4% and 67.4% (P >.05), respectively., Conclusions: Although FE demonstrated a great sensitivity, cytology still has a role even when using FE, because a small group of patients with high-grade tumors were detected by urinary cytology only., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Carcinoma of the prostate (PC) is the most common cancer in men. Ultrasound (US)-guided prostate biopsy with 10-12 cores is considered to be the gold standard in the diagnosis of PC, although a systematic biopsy may miss a considerable percentage of prostate cancer. Substantial efforts have been made to improve the detection rates with extensive prostate biopsy schemes. Today, the most promising tools to improve the detection rate are various imaging procedures. This review focuses on the current stautus of ultrasound imaging in the detection of PC, such as contrast-enhanced colour Doppler ultrasound and real-time elastography. With the use of these techniques, it is the intention not only to improve the detection rate but they could also serve beneficial for staging and in order to reduce the number of biopsy cores. However, further clinical trials will be needed to determine the value of these new US advances.

Objective: To evaluate the possible benefit of fluorescence cystoscopy (FC) in detecting cytologically 'confirmed' lesions when assessing urothelial carcinoma of the bladder, as negative white-light cystoscopy in cases of a positive cytological finding represents a diagnostic dilemma., Patients and Methods: From January 1996 to December 2006, 348 patients, who had cystoscopy for surveillance or due to suspicion of urothelial carcinoma, presented with an entirely negative white-light cystoscopy at our hospital. However, 77 of the 348 patients (22.2%) were diagnosed with a positive cytological finding. All patients had white-light cystoscopy first and a bladder-wash cytological specimen was obtained, then FC, followed by cold-cup biopsies and/or transurethral resection of the bladder tumour., Results: In the 77 patients with a positive cytological specimen FC enabled the detection of the precise site of malignancy within the bladder in 63 (82%). As malignant or premalignant lesions, there were 18 moderate dysplasias, 27 carcinoma in situ (CIS), and 18 pTa-1/G1-3 tumours. Moreover using FC, malignant or premalignant lesions were detected in 43 of 271 patients (15.9%) who had a negative cytological specimen (15 moderate dysplasias, six CIS, 22 pTa-1/G1-3)., Conclusion: This study shows that FC is beneficial in the detection of malignant and premalignant lesions, if there is negative white-light cystoscopy but positive urine cytology. The immediate identification of the exact site of a malignant lesion during FC enables the physician to diagnose and treat these patients more accurately and with no delay.