Resistance to the mTOR-inhibitor RAD001 elevates integrin α2- and ß1-triggered motility, migration and invasion of prostate cancer cells.

BACKGROUND: Inhibitors of the mammalian target of rapamycin (mTOR) might become a novel tool to treat advanced prostate cancer. However, chronic drug exposure may trigger resistance, limiting the utility of mTOR inhibitors. METHODS: Metastatic potential of PC3 prostate cancer cells, susceptible (PC3(par)) or resistant (PC3(res)) to the mTOR-inhibitor RAD001 was investigated. Adhesion to vascular endothelium or immobilised collagen, fibronectin and laminin was quantified. Motility, migration and invasion were explored by modified Boyden chamber assay. Integrin α and ß subtypes were analysed by flow cytometry, western blotting and real-time PCR. Integrin-related signalling, EGFr, Akt, p70S6kinase and ERK1/2 activation were determined. RESULTS: Adhesion was reduced, whereas motility, migration and invasion were enhanced in PC3(res). The α2 and ß1 integrin subtypes were dramatically elevated, integrins α1 and α6 were lowered, whereas α5 was nearly lost in PC3(res). Activation of the Akt signalling pathway was strongly upregulated in these cells. Treating PC3(par) cells with RAD001 reduced motility, migration and invasion and deactivated Akt signalling. Blocking studies revealed that α2 and ß1 integrins significantly trigger the motile behaviour of the tumour cells. CONCLUSION: Chronic RAD001 treatment caused resistance development characterised by distinct modification of the integrin-expression profile, driving prostate cancer cells towards high motility.

Prostaglandin E2 and tumor necrosis factor alpha cooperate to activate human dendritic cells: synergistic activation of interleukin 12 production.

Interleukin (IL)-12 is a proinflammatory cytokine that contributes to innate resistance and to the development of antigen-specific T cell responses. Among other effects, prostaglandin E2 (PGE2) inhibits the production of IL-12 by macrophages activated with lipopolysaccharide (LPS). Here we investigated the effects of PGE2 on human dendritic cells (DCs) which develop in the presence of GM-CSF and IL-4. We demonstrate that in the absence of LPS, PGE2 dose dependently stimulated the production of IL-12 by DCs. Although PGE2 alone stimulated the production of low amounts of IL-12 only, it synergized with tumor necrosis factor (TNF)-alpha to induce high levels of IL-12 production by DCs. Addition of TNF-alpha in the absence of PGE2 had no effect on IL-12 production. Conversely, in the presence of LPS, PGE2 inhibited IL-12 production by DCs in a dose-dependent manner. The combination of PGE2 and TNF-alpha efficiently silenced mannose receptor-mediated endocytosis in DCs and readily induced neo-expression of the CD83 antigen. In addition, the expression of various surface antigens such as major histocompatibility complex class I and II, adhesion, as well as costimulatory molecules was upregulated by this treatment. The effects of PGE2 on IL-12 synthesis and CD83 expression could be mimicked by dibutyryl-cAMP and forskolin, indicating that they were due to the intracellular elevation of cAMP levels. DC treated with PGE2 and TNF-alpha were most potent in stimulating allogeneic T cell proliferation. Our data demonstrate that PGE2 contributes to the maturation of human DCs and that PGE2 can be a potent enhancer of IL-12 production by human DCs.

Transrectal ultrasound as diagnostic tool for the detection of local recurrence following cystectomy and urinary diversion.

OBJECTIVE: Routine follow-up after cystectomy for bladder cancer detect patients with local recurrence late in the course of disease. We set out to determine the value of transrectal ultrasound (TRUS) as diagnostic tool to diagnose local failure. PATIENTS AND METHODS: Between 1986 and 2003, radical cystectomy for bladder cancer with orthotopic diversion was performed in 642 male patients. We identified all patients that simultaneously had transabdominal ultrasound, digital rectal examination, TRUS and CT/MRI of the pelvis at the diagnosis of local recurrence. RESULTS: Mean follow-up was 59.4 months. 83/642 patients (13%) had local failure of bladder cancer during follow-up. In 48/642 patients (7.5%) the local recurrence was the first site of recurrence. 35/642 patients (5.5%) developed local failure with concomitant distant disease. 31/83 patients met the inclusion criteria. The median time between cystectomy and diagnosis of local recurrence was 13 months (2-51 months). Routine follow-up detected local recurrence in 1 asymptomatic patient. 25/31, 3/31 and 2/31 patients had pain in the lower extremities/pelvis, hematuria and urinary retention, respectively. Digital rectal examination, transabdominal ultrasound, TRUS, and CT/MRI of the pelvis were suspicious for local recurrence in 9, 7, 26, and 29 patients, respectively. CONCLUSIONS: TRUS is a highly sensitive tool in detecting local recurrence following cystectomy. It is easy to perform and inexpensive. We recommend TRUS in short intervals in all patients with high risk for local recurrence in order to detect cancer early.

Trend analysis and regional tumor incidence in Germany for testicular cancer between 2003 and 2014.

BACKGROUND: Testicular germ cell tumor (TGCT) is one the most common solid tumors in men between the age of 15 and 35 with an overall incidence rate of 1-1.5 %. Epidemiologic studies have demonstrated different incidence patterns in western civilized countries with overall rising incidence trends. OBJECTIVE: To analyze differences in regional tumor incidence rates for TGCT and perform a trend analysis for TGCT between 2003 and 2014 in Germany. MATERIAL AND METHODS: TGCT cases in Germany which were diagnosed between 2003 and 2014 were provided by the Robert-Koch-Institute, Berlin. For statistical analysis, cluster and spatial scan tests according to Kulldorff were used for cases with seminoma and non-seminoma. Results are presented in administrative districts and graphically illustrated. We performed a trend-analysis in order to evaluate age-adjusted incidence trends in Germany. Tests were two-sided with a level of significance of α=0.05. RESULTS: In total we included 35,066 patients. Overall, 22,634 cases had newly diagnosed seminoma and 12,432 were diagnosed as non-seminoma. Maximum incidence of seminoma and non-seminoma was observed for age-group 38-40 years and 26-28 years, respectively. No second peak for the incidences of seminoma and non-seminoma with respect to age were observed. Cluster analysis revealed areas with high and low incidence rates as well as slightly different spatial distribution in Germany between seminoma and nonseminoma. Furthermore, there was no significant increase in age-adjusted incidence rates over the reviewed time period in both cohorts. DISCUSSION: In this study differences in reginal tumor incidence rates for seminoma and non-seminoma are reported with both tumor entities revealing distinct clusters. Furthermore, tumor incidence trends for seminoma and nonseminoma between 2003 and 2014 were stable which might indicate the beginning of a plateau phase for TGCT incidence rates in Germany. CONCLUSION: In this analysis we were able to identify regions with significantly higher tumor incidence rates for both seminoma and non-seminoma which were specific for these two subtypes. Furthermore, trend analysis revealed a steady incidence rate for testicular cancer in Germany.

The efficacy of dihydrotestosterone transdermal gel before primary hypospadias surgery: a prospective, controlled, randomized study.

PURPOSE: We sought to evaluate the efficacy of transdermal dihydrotestosterone treatment based on the results of hypospadias repair in children with primary hypospadias. MATERIALS AND METHODS: A total of 75 randomized consecutive children who were a mean of 33.4 +/- 3.7 months old and had primary hypospadias were included in the study between September 2004 and April 2006. While 37 children were treated with 2.5% transdermal gel daily, applied directly onto the penile shaft and glans for 3 months (group 1), 38 children did not receive any treatment preoperatively (group 2). All children underwent hypospadias repair using tubularized incised plate urethroplasty. Postoperative complications were analyzed using the Mann-Whitney U test with respect to fistulas, urethral strictures, diverticula, meatal stenosis, glanular dehiscence and scar formation according to the results at 1-year followup. RESULTS: Mean ages of the children in groups 1 and 2 were similar (30.8 +/- 5.4 months and 35.1 +/- 5.1 months, respectively). The urethral meatus was coronal in 70%, penile in 24% and penoscrotal in 5% of the patients in group 1, while it was coronal in 84% and penile in 16% of the patients in group 2. Postoperative complications included urethrocutaneous fistula in 4 patients (11%) in group 2, compared to 1 patient (3%) in group 1 (p >0.05). While 3 patients (8%) in group 2 had glanular dehiscence, no patient in the dihydrotestosterone group had this complication (p <0.05). There were 2 patients with meatal stenosis in group 2 (5%), and no patient with meatal stenosis in group 1 (p >0.05). In addition, there were 16 patients (42%) with moderate to severe postoperative scar formation in group 2, compared to only 2 patients (5%) in the dihydrotestosterone group (p <0.05). Finally, there was a significant difference between the overall reoperation rates of group 2 (9 patients, 24%) and group 1 (1 patient, 3%, p <0.05). None of our patients had signs or symptoms of urethral stricture or urethral diverticulum. CONCLUSIONS: Pretreatment with dihydrotestosterone transdermal gel was effective in decreasing the complications and improving the cosmetic results after hypospadias repair.

Extracellular microenvironment and cytokine profile of the ureterovesical junction in children with vesicoureteral reflux.

PURPOSE: Vesicoureteral reflux is caused by a defective valve mechanism of the ureterovesical junction. Previous studies have revealed structural and metabolic changes in the intravesical ureter, impairing its contractile properties. Smooth musculature and nerves are replaced by collagen, while matrix degrading enzymes are over expressed. We investigated the presence of regulating cytokines and the extracellular matrix composition to elucidate further the pathophysiology of vesicoureteral reflux. MATERIALS AND METHODS: Ureteral endings were obtained from 28 children during antireflux surgery, and 14 age matched autopsy specimens served as controls. Routine histological sections were immunostained for insulin-like growth factor-1, nerve growth factor, transforming growth factor-beta1, tumor necrosis factor-alpha and vascular endothelial growth factor. Smooth muscle staining was supplemented by tenascin C, tetranectin and fibronectin detection. Staining patterns were investigated using computer assisted, high power field magnification analyses. RESULTS: Tumor necrosis factor-alpha and transforming growth factor-beta1 were significantly more abundant in vesicoureteral reflux samples, whereas insulin-like growth factor-1, nerve growth factor and vascular endothelial growth factor were more prevalent in healthy controls. Fibronectin was intensely expressed in refluxing ureters, while it was scarce in healthy children. Tenascin C was notable within the urothelium of both groups. Only vesicoureteral reflux samples displayed tenascin C in the musculature and connective tissue. Tetranectin staining was only detected in vesicoureteral reflux. CONCLUSIONS: Several cytokines are differentially expressed in primary refluxing ureters, indicating an ongoing tissue remodeling process in the ureterovesical junction region. Additionally, the smooth muscle coat is widely lacking, while extracellular matrix proteins typical for tissue shrinkage and reorganization are over expressed. These alterations are likely to contribute to the malfunctioning active ureteral valve mechanism in primary vesicoureteral reflux.

5-alpha-reductase and the development of the human prostate.

During the 10(th) week of gestation human prostate development is about to start. Androgens are the crucial factors to stimulate the initial interactions between the epithelium and mesenchyme. One of the key events in androgen metabolism is the transformation of circulating testosterone to 5alpha-dihydrotestosterone (DHT) by tissue-linked 5alpha-reductase. Both, the formation of a male phenotype and the androgen-mediated growth of the prostate are mediated by DHT. To date the function of 5alpha-reductase 1 (5alphaR1) still remains unclear whereas 5alpha-reductase 2 (5alphaR2) is supposed to be the predominant isoenzyme in human accessory sex tissue. Only little data are available on the detection, distribution, and effects of both isoenzymes during fetal life and infancy. Recently, immunohistochemical investigations of serial sections from fetuses and infants using specific antibodies directed against 5alphaR1 and 5alphaR2 seem to shed light on that issue. Moreover, the detection of downstream products of androgen synthesis using RT-PCR analyses for 17-beta hydroxysteroid dehydrogenase Type 2 (17 betaHSD 2), 17 betaHSD Type 3 and 17 betaHSD Type 7 adds to discovering the molecular biological background. New studies confirm that both isoenzymes are present throughout fetal development. On the transcriptional level RT-PCR for 5alphaR1 and 5alphaR2 certifies these findings. 17 betaHSD 2, 3 and 7 representing the most relevant enzymatic downstream products of cellular androgen synthesis were revealed by RT-PCR as well. Current studies discovered the expression and distribution of both 5alpha-reductase isoenzymes as well as the potential contribution of 5alphaR1 during fetal human prostate development.

[History of high-flow priapism: 1960-2005]. / Geschichte des High-flow-Priapismus: 1960-2005.

High-flow priapism caused by a pathological arterial influx to the cavernous bodies was first described by F.B. Burt in 1960. The pathophysiological differentiation of high- and low-flow priapism was developed in 1983. The development of diagnostic tools for differentiation of different forms of priapism and the progress in the therapy of high-flow priapism from arterial ligation to supraselective embolization is presented.

Distant metastases from prostatic carcinoma express androgen receptor protein.

Nearly all primary prostatic carcinomas have been found to express the androgen receptor (AR) protein, which is the intracellular mediator of androgen action. To gain a better insight into the mechanisms of androgen independence of advanced prostatic carcinoma, it is important to know whether the AR is also present in metastases of androgen-independent tumors. We have assessed the status of the AR and the prostate-specific antigen in 22 metastases of 18 patients with progressive prostate cancer. In 18 cases, the metastases were localized in bone, in 3 cases in the epidural space, and in 1 case in the periosteum. All but one patient had received some kind of endocrine treatment for prostatic carcinoma. Paraffin-embedded tissue sections were stained for the AR following a streptavidinbiotin-peroxidase protocol with the polyclonal antibody PG-21, which is directed against amino acids 1 through 21 of the rat and the human AR. The percentage of AR-positive cells was evaluated on the basis of an arbitrary 4-point scale. All 22 tumor metastases displayed AR positivity. One AR-positive metastatic lesion did not stain for prostate-specific antigen, but in all other metastases, this protein was detected by means of immunohistochemistry. The present study provides evidence that, unlike androgen-independent prostatic carcinoma cell lines, distant prostatic carcinoma metastases do express the AR. These findings indicate that the AR may be involved in the progression of prostate cancer.

Androgen receptor activation in prostatic tumor cell lines by insulin-like growth factor-I, keratinocyte growth factor, and epidermal growth factor.

Aberrant activation of the androgen receptor (AR) may be one of the mechanisms which contribute to progression of prostatic carcinoma to an androgen-independent stage. We investigated effects of growth factors on stimulation of the AR-mediated gene transcription in human prostatic tumor cell lines. DU-145 cells, which do not contain endogenous AR, were cotransfected with an androgen-inducible chloramphenicol acetyltransferase (CAT) reporter gene and an AR expression vector. The reporter gene (CAT) was driven either by artificial promoters consisting of one or two androgen-responsive elements in front of a TATA box or by the promoter of the prostate-specific antigen (PSA) gene, a naturally occurring androgen-inducible promoter. Insulin-like growth factor-I (IGF-I), at a concentration of 50 ng/ml, stimulated AR-mediated reporter gene transcription to the same extent as the synthetic androgen methyltrienolone. This growth factor was effective irrespective of the nature of the androgen-inducible promoter. Keratinocyte growth factor (KGF) and epidermal growth factor (EGF), at concentrations of 50 ng/ml, activated CAT reporter gene transcription only in experiments in which the artificial promoter with two androgen-responsive elements was used. Insulin-like growth factor-II and basic fibroblast growth factor displayed no effect on AR-mediated gene transcription. None of the growth factors stimulated reporter gene activity in control experiments when added to cells cotransfected with the CAT gene and an empty expression vector. AR activation by IGF-I, KGF, and EGF was completely inhibited by the pure AR antagonist casodex, showing that these effects are AR mediated. Activation of endogenous AR by growth factors was studied in the LNCaP cell line by determination of PSA secretion. IGF-I, at a concentration of 50 ng/ml, increased the PSA level in the supernatant of this cell line 5-fold. Again, the IGF-I effect on PSA secretion was blocked by casodex. Our results provide evidence that IGF-I, KGF, and EGF directly activate the AR in the absence of androgens, which means that the androgen-signaling chain may be activated by growth factors in an androgen-depleted environment. These findings may have implications for endocrine therapy for metastatic prostatic carcinoma.

Interleukin-6 regulates prostate-specific protein expression in prostate carcinoma cells by activation of the androgen receptor.

Interleukin-6 (IL-6) levels are frequently elevated in sera of patients with metastatic prostate cancer. IL-6 receptors are expressed in prostate cancer cell lines, as well as in benign prostate hyperplasia and prostate cancer tissue specimens. The androgen receptor (AR) is a key transcription factor that is present in all stages of prostate carcinoma, even in therapy-refractory tumors. In an attempt to investigate possible cross-talk between IL-6 and androgen signal transduction cascades, we tested the effects of this cytokine on AR transcriptional activity. The regulation of AR activity by IL-6 was studied in DU-145 cells, which were cotransfected with the androgen-responsive reporter plasmid ARE2TATACAT and the AR expression vector pSG5AR. We show that IL-6 up-regulates AR activity in a ligand-independent manner, as well as synergistically, with very low doses of the synthetic androgen methyltrienolone (5-10 pM). Therefore, AR activation by IL-6 may be operative in prostate cancer patients who have decreased androgen levels because of androgen ablation therapy. The maximal induction of reporter gene activity by IL-6 alone (50 ng/ml) was 67% of that stimulated by 1 nM of methyltrienolone. The nonsteroidal antiandrogen bicalutamide (Casodex) nearly completely inhibited AR activation by IL-6. IL-6 effects on AR activity were also abolished or greatly reduced by inhibitors of protein kinase A and C and mitogen-activated protein kinase pathways. In concordance with the results obtained in DU-145 cells, IL-6 induced AR-regulated prostate-specific antigen mRNA and protein in LNCaP cells. Stimulation of prostate-specific antigen protein secretion by IL-6 was antagonized by bicalutamide and inhibitors of protein kinase A and mitogen-activated protein kinase signaling pathways. Taken together, our data show for the first time that IL-6 is a nonsteroidal activator of the AR and that this activation is implicated in the regulation of prostate-specific proteins. Keeping in mind that IL-6, its receptor, and the AR are expressed in prostate cancers, cross-talk between IL-6 and AR signaling pathways may have clinical significance.

Epidermal growth factor (EGF) receptor blockade inhibits the action of EGF, insulin-like growth factor I, and a protein kinase A activator on the mitogen-activated protein kinase pathway in prostate cancer cell lines.

Epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) are potent mitogens that regulate proliferation of prostate cancer cells via autocrine and paracrine loops and promote tumor metastasis. They exert their action through binding to the corresponding cell surface receptors that initiate an intracellular phosphorylation cascade, leading to the activation of mitogen-activated protein kinases (MAPKs), which recruit transcription factors. We have studied the effects of EGF, IGF-I, and the protein kinase A (PKA) activator forskolin on the activation of p42/ extracellular signal-regulated kinase (ERK)2, which is a key kinase in mediation of growth factor-induced mitogenesis in prostate cancer cells. The activity of p42/ERK2 was determined by immune complex kinase assays and by immunoblotting using a phospho p44/p42 MAPK-specific antibody. EGF, IGF-I, and forskolin-induced PKA activity stimulate intracellular signaling pathways converging at the level of p42/ERK2. In the androgen-insensitive DU145 cell line, there is a constitutive basal p42/ ERK2 activity that is not present in androgen-sensitive LNCaP cells. Constitutive p42/ERK2 activity is abrogated by blockade of the EGF receptor. Hence, it is obviously caused by an autocrine loop involving this receptor. The effects of EGF on p42/ERK2 are potentiated by forskolin in both cell lines. The blockade of PKA by the specific inhibitor H89 attenuates this synergism. This finding is in contrast to those obtained in several other systems studied thus far, in which PKA activators inhibited MAPKs. p42/ERK2 in DU145 cells is highly responsive to IGF-I stimulation, whereas no effect of IGF-I on p42/ERK2 can be measured in LNCaP cells. Moreover, our results demonstrate that selective blockade of the EGF receptor in prostate cancer cells does not only inhibit the action of EGF, but also IGF-I-induced activation of the MAPK pathway and the interaction with the PKA pathway. In conclusion, these findings offer new possibilities for a therapeutical intervention in prostate cancer by targeting signaling pathways of growth factors and PKA.

[Patient blood management: Current state of the literature]. / Patient-blood-Management : Stand der aktuellen Literatur.

BACKGROUND: Preoperative anemia has a prevalence of approximately 30% and is one of the strongest predictors of perioperative red blood cell (RBC) transfusion. It is rarely treated although it is an independent risk factor for the occurrence of postoperative complications. Additionally, the high variability in the worldwide usage of RBC transfusions is alarming. Due to these serious deficits in patient care, in 2011 the World Health Organization recommended the implementation of a patient blood management (PBM). OBJECTIVES: This article provides information about PBM as a multidimensional and interdisciplinary approach. MATERIAL AND METHODS: A selective literature search was carried out in the Medline and Cochrane library databases including consideration of national and international guidelines. RESULTS: A PBM promotes the medically and ethically appropriate use of all available resources, techniques and materials in favor of an optimized perioperative patient care. Patients' own resources should be specifically protected, strengthened and used and include (i) diagnosis and therapy of preoperative anemia, (ii) minimizing perioperative blood loss, (iii) blood-conserving surgical techniques, (iv) restriction of diagnostic blood sampling, (v) utilization of individual anemia tolerance, (vi) optimal coagulation and hemotherapy concepts and (vii) guideline-based, rational indications for the use of RBC transfusions. CONCLUSION: A PBM should be advocated as an incentive to evaluate and critically optimize local conditions. An individual, interdisciplinarily structured bundle of different PBM measures has great potential to optimize the quality of patient care and to make it safer.

[Urolithiasis 2016 : Reliable, effective and low radiation exposure]. / Steindiagnostik 2016 : Zuverlässig, effektiv und strahlungsarm.

BACKGROUND: Urolithiasis is a widespread disease. Diagnostic imaging plays an important role in the evaluation and management of patients with suspected urolithiasis. Furthermore, modern imaging methods may provide information on stone location, size, fragility and composition aiding the urologist to determine the appropriate treatment modality. PURPOSE: Based on the current literature and guidelines, this review reports on the various new and established diagnostic imaging modalities. RESULTS: Ultrasound should always be the initial imaging modality. Following ultrasound, noncontrast CT-principally using a low-dose protocol-is the imaging modality of choice in the evaluation of patients with acute flank pain and suspected urolithiasis. New imaging modalities like dual energy CT, Uro Dyna CT and digital tomosynthesis are currently under investigation but not yet part of daily clinical practice. Magnetic resonance imaging can be used to detect obstruction caused by urinary stones but is not a first-line imaging modality.

Mechanisms of endocrine therapy-responsive and -unresponsive prostate tumours.

Several options for the endocrine treatment of non-organ-confined prostate cancer are available. They include surgical or medical removal of androgenic hormones or administration of non-steroidal anti-androgens. However, tumour progression after a period of remission of the disease inevitably occurs in virtually all patients. The androgen receptor (AR) is, in various tumour models, implicated in the development of therapy resistance but molecular mechanisms that by-pass the receptor have also been described. Adaptation mechanisms relevant to tumour recurrence include up-regulation of AR mRNA and protein, overexpression of AR coactivators, increased activation of mutated receptors by steroids and anti-androgens, and ligand-independent activation. For research studies, sublines that respond to but do not depend on androgen for their proliferation were generated. Coactivators SRC-1, TIF-2, RAC3, p300, CBP, Tip60, and gelsolin are highly expressed in endocrine therapy-resistant prostate cancer. AR point mutations are increasingly detected in relapsed cancers and contribute to the failure of endocrine therapy in a subgroup of patients. Ligand-independent activation of the AR by HER-2/neu and interleukin-6 is associated with activation of the signalling pathway of mitogen-activated protein kinase. Increased activity of intracellular kinases may affect cellular events in both an AR-dependent and -independent manner. Mitogen-activated protein kinases are strongly phosphorylated in endocrine therapy-resistant prostate tumours. Similarly, activation of the AR by phosphorylated protein kinase B, Akt, has also been reported in prostate cancer. Activation of the Akt pathway contributes to increased survival of prostate tumour cells.

Changing diagnostic and therapeutic concepts in high-flow priapism.

High-flow priapism (HFP) is defined as pathological increased arterial influx into the cavernosal bodies. Since 1960, 202 cases have been published in the literature. This study evaluates the effect of the changing diagnostic and therapeutic concepts. The data of 202 cases of HFP was evaluated regarding diagnostic and therapeutic procedures and long-term results. Success was defined as restored erectile function without recurrent priapism. The major etiology of HFP is trauma, especially in children or young adults; in older men, HFP is a rare event mainly caused by malignoma. Cavernosal blood-gas analysis, color-Doppler ultrasound and angiography were the most effective diagnostic tools to distinguish high- from low-flow priapism. The success rate was 20% for shunt operations and 89% for arterial embolization. In conclusion, embolization was effective in the majority of cases of traumatic HFP, while shunt surgery remained disappointing. For HFP caused by inherited diseases and malignoma conservative therapy is mandatory.

Prostate cancer cells (LNCaP) generated after long-term interleukin 6 (IL-6) treatment express IL-6 and acquire an IL-6 partially resistant phenotype.

PURPOSE: The levels of interleukin-6 (IL-6) are frequently elevated in sera from patients with advanced prostate carcinoma. Our main objective was to investigate changes in responsiveness to IL-6 and/or androgen that occur in LNCaP cells after long-term treatment with IL-6. This in vitro model could be of clinical relevance because of its similarity with late-stage prostate carcinoma. EXPERIMENTAL DESIGN: LNCaP human prostate cancer cells were treated with IL-6 at a concentration of 5 ng/ml. After 20 passages, the new subline LNCaP-IL-6+ has been established. Passages 20-40 are referred to as low passages (LP) and passages 41-73 as high passages (HP). LNCaP cells passaged at the same time in the absence of IL-6 were used as controls (LNCaP-IL-6-). Cells were counted after treatment with either IL-6 or the synthetic androgen methyltrienolone (R1881), and cell cycle analysis was performed. Binding of IL-6 or R1881 was assessed by radioligand binding assays. Reporter gene activity was measured by chloramphenicol acetyltransferase assay. Prostate-specific antigen in LNCaP-IL-6+ supernatants was measured by an enzyme immunoassay. Expression of IL-6 mRNA and protein was assessed by reverse transcription-PCR and ELISA, respectively. RESULTS: The basal proliferation rate in HP LNCaP-IL-6+ cells was higher than that in LNCaP-IL-6- cells. IL-6 inhibited proliferation of LNCaP-IL-6- cells but not that of either LP or HP of LNCaP-IL-6+ cells. This inability to elicit a growth-inhibitory response was associated with lack of effect on cell cycle distribution in the LNCaP-IL-6+ subline. In parallel, IL-6 binding decreased gradually during long-term IL-6 treatment and, in HP, reached only 33% of the levels measured in controls. Binding of radiolabeled androgen increased 2-fold in HP LNCaP-IL-6+ cells. Reporter gene assays revealed that R1881, at nanomolar concentrations, was a more potent androgen receptor activator in LNCaP-IL-6+ than in LNCaP-IL-6- cells. However, androgen- and IL-6-induced prostate-specific antigen secretion decreased in long-term IL-6-treated cells. IL-6 cDNA fragments were detected by reverse transcription-PCR in HP LNCaP-IL-6+ cells but not in controls or LP. IL-6 protein was first detected in passage 36 of LNCaP-IL-6+ cells, and it increased in HP. CONCLUSIONS: Long-term treatment of LNCaP human prostate cancer cells with IL-6 leads to abolishment of inhibitory growth response. In contrast to control cells, the LNCaP-IL-6+ subline expresses IL-6 mRNA and protein.

Mutant androgen receptor detected in an advanced-stage prostatic carcinoma is activated by adrenal androgens and progesterone.

Structural changes of the androgen receptor (AR) may contribute to the development of resistance to endocrine therapy in prostatic carcinoma. We have isolated AR cDNA fragments from seven tumor specimens derived from patients with advanced metastatic prostatic tumors. In one specimen obtained from a patient who failed to respond to endocrine and cytotoxic therapy we have detected a point mutation in the hormone-binding domain of the receptor. This AR mutation is a guanine-to-adenine transition at nucleotide 2671 that leads to substitution of methionine for the wild type valine at position 715. It is a somatic mutation because it was not present in the AR genomic DNA fragments isolated from prostatic and testicular tissues of the same patient. The mutant AR was recreated in an expression vector and transiently expressed in COS-7 and CV-1 cells. Hormone-binding assays revealed that the mutant receptor does not differ from the wild type receptor in its ability to bind androgen. The dissociation constant for the synthetic androgen mibolerone was 3 nM for both receptors. There was also no significant difference in binding of other steroids and nonsteroidal antiandrogens as revealed by competition binding assays. However, transfection experiments to determine the trans-activation potential of the mutant receptor produced differences in the action of this receptor compared to the wild type receptor. Dihydrotestosterone and the synthetic androgens methyltrienolone (R1881) and mibolerone were equally proficient in conferring trans-activation activity to both the mutant and wild type receptors. Adrenal androgens such as dehydroepiandrosterone and androstenedione, as well as progesterone mediated a higher trans-activation through the mutant than through the wild type receptor. These data demonstrate that the exchange of a single valine into methionine at position 715 in the AR promoters trans-activation not only by testicular but also by adrenal androgens and progesterone. This pattern of ligand-dependent trans-activation may have significance in the process controlling the progression of prostatic carcinoma.

Nordihydroguaiaretic acid blocks secretory and endocytic pathways in human dendritic cells.

Nordihydroguaiaretic acid (NDGA), an antioxidant and inhibitor of the lipoxygenase arm of the arachidonic acid metabolism, was recently demonstrated to inhibit transport of secretory proteins to the Golgi complex. We have investigated the effects of NDGA on the secretory and endocytic activity of cultured human blood dendritic cells (DC). Treatment with NDGA strongly diminished cytokine secretion by DC. Moreover, NDGA reduced in a dose- and time-dependent fashion fluid phase as well as receptor-mediated endocytosis in DC. Zileuton and MK-886, specific inhibitors of 5-lipoxygenase and 5-lipoxygenase-activating protein, respectively, had no effect. Likewise, N-acetyl-L-cysteine, a thiol antioxidant precursor of glutathione, did not affect DC function. Finally, serum remarkably protected the cells from the inhibitory effects of NDGA. Our data demonstrate that NDGA not only disrupts vesicular transport along the secretory route but is also a potent inhibitor of the endocytic pathways in human DC and that NDGA has inhibitory properties different from those described.

Antiandrogens in prostate cancer endocrine therapy.

Prostate cancer is the most frequently diagnosed tumor in industrialized countries. Endocrine therapy, which is based on interference with androgen signaling is only palliative. Drugs used in prostate cancer therapy are luteinizing hormone releasing hormone (LHRH) agonists and antiandrogens. Application of LHRH agonists leads to suppression of the levels of circulating androgens, and antiandrogens block the function of the androgen receptor (AR). The steroidal antiandrogen cyproterone acetate and nonsteroidal compounds hydroxyflutamide and bicalutamide are used most frequently. They prevent acquisition of a transcriptionally active conformation of the AR. It became clear that tumors progress to therapy resistance in the presence of the AR which might be structurally altered. These mutations generate receptors that respond to other steroids and antiandrogens by increased activation. In addition, AR expression increases during endocrine treatment. AR is also activated by nonsteroidal compounds such as growth factors, interleukin-6, and neuropeptides. Therefore, new experimental approaches are needed to antagonize AR expression and function more efficiently. The AR associates with a number of proteins, coactivators and corepressors. There are indications that expression of some of these proteins is altered in prostate cancer, a fact which might be important for improvement of endocrine therapy.