Prostate specific antigen enhances the innate defence of prostatic epithelium against Escherichia coli infection

BACKGROUND

This study investigated whether the increase in serum prostate specific antigen (PSA) typically seen during male urinary tract infection (UTI) is incidental or reflects an innate defence mechanism of the prostate. The protective roles of the whey-acid-motif-4-disulphide core (WFDC) proteins, secretory leukoproteinase inhibitor (SLPI) and WFDC2, in the prostate were also examined.

METHODS

UTI recurrence was assessed retrospectively in men following initial UTI by patient interview. PSA, SLPI, and WFDC2 gene expression were assessed using biopsy samples. LNCaP and DU145 in vitro prostate cell models were utilized to assess the effects of an Escherichia coli challenge on PSA and WFDC gene expression, and bacterial invasion of the prostate epithelium. The effects of PSA on WFDC antimicrobial properties were studied using recombinant peptides and time-kill assays.

RESULTS

Men presenting with PSA >4 ng/ml at initial UTI were less likely to have recurrent (r) UTI than those with PSA <4 ng/ml [2/15 (13%) vs. 7/10 (70%), P < 0.01]. Genes encoding PSA, SLPI and WFDC2, were expressed in prostatic epithelium, and the PSA and SLPI proteins co-localized in vivo. Challenging LNCaP (PSA-positive) cells with E. coli increased PSA, SLPI, and WFDC2 gene expression (P < 0.05), and PSA synthesis (P < 0.05), and reduced bacterial invasion. Pre-incubation of DU145 (PSA-negative) cells with PSA also decreased bacterial invasion. In vitro incubation of recombinant SLPI and WFDC2 with PSA resulted in peptide proteolysis and increased E. coli killing.

CONCLUSIONS

Increased PSA during UTI appears protective against rUTI and in vitro is linked to proteolysis of WFDC proteins supporting enhanced prostate innate defences.

Renal differentiation from adult spermatogonial stem cells

There is considerable interest in the use of multi-potent stem cells in kidney tissue regeneration. We studied if spermatogonial stem cells have the ability to undergo kidney differentiation. Spermatogonial stem cell differentiation was induced using in vitro and ex vivo co-culture techniques. Conditioned media from human kidney fibroblasts induced the expression of epithelial and endothelial lineages in spermatogonial stem cells, consistent with nephrogenesis. Furthermore, we showed that these cells up-regulated renal tubular-specific markers alkaline phosphatase, mineralocorticoid receptor, renal epithelial sodium channel and sodium-glucose transporter-2 (p<0.05). GFP-labeled spermatogonial stem cells were engrafted into metanephric kidney organ cultures harvested from E12.5 mouse embryos. After 5 days of organ culture, focal anti-GFP staining was detectable in all inoculated kidneys demonstrating integration of spermatogonial stem cells into the developing kidney (p<0.01). Histological assessment showed early nephron-like architecture. In summary, we show that spermatogonial stem cells have the potential to generate renal tissue and lay the foundations for further investigations into a novel therapeutic approach for renal insufficiency.

Penile strangulation by a substantial metal napkin ring: successful removal with medtronic midas rex® legend® stylus® drill system

We report the case of a 34-year-old with penile constriction by a large solid steel ring napkin holder in whom attempts of removal by conventional techniques failed. Standard instruments available in urology and general surgical theatres proved too weak to sever the ring and those offered by the fire services were grossly oversized and dangerous to use around the genitalia. Orthopaedic staff offered an instrument not previously used within our urology department: the Medtronic Midas Rex© Legend EHS Stylus High-Speed Surgical Drill. This intricate electronic powered drill allowed quick, controlled and safe incision of the metal ring, relieving the constriction. In addition to this first report of a metal penile constriction device removed using the Medtronic Midas Rex® Legend® Drill System, we review the literature on penile constriction and management strategies.

A review of tasquinimod in the treatment of advanced prostate cancer

Castration resistant prostate cancer remains a major clinical burden and novel therapeutic options are urgently required to improve survival. Tasquinimod is an orally administered quinoline-3-carboxamide with potent antiangiogenic and antitumorigenic action that has shown promise in the treatment of advanced prostate cancers. This review explores both preclinical and clinical findings to date. In summary, tasquinimod has been shown to demonstrate a potent in vitro and in vivo anticancer action and completed early phase clinical trials have demonstrated good drug tolerance and prolonged progression-free survival. Although Phase III clinical trials are on-going, the findings to date highlight the promise of this drug in the treatment of advanced prostate cancer.

The lysine demethylase, KDM4B, is a key molecule in androgen receptor signalling and turnover

The androgen receptor (AR) is a key molecule involved in prostate cancer (PC) development and progression. Post-translational modification of the AR by co-regulator proteins can modulate its transcriptional activity. To identify which demethylases might be involved in AR regulation, an siRNA screen was performed to reveal that the demethylase, KDM4B, may be an important co-regulator protein. KDM4B enzymatic activity is required to enhance AR transcriptional activity; however, independently of this activity, KDM4B can enhance AR protein stability via inhibition of AR ubiquitination. Importantly, knockdown of KDM4B in multiple cell lines results in almost complete depletion of AR protein levels. For the first time, we have identified KDM4B to be an androgen-regulated demethylase enzyme, which can influence AR transcriptional activity not only via demethylation activity but also via modulation of ubiquitination. Together, these findings demonstrate the close functional relationship between AR and KDM4B, which work together to amplify the androgen response. Furthermore, KDM4B expression in clinical PC specimens positively correlates with increasing cancer grade (P < 0.001). Consequently, KDM4B is a viable therapeutic target in PC.

Side population in human non-muscle invasive bladder cancer enriches for cancer stem cells that are maintained by MAPK signalling

Side population (SP) and ABC transporter expression enrich for stem cells in numerous tissues. We explored if this phenotype characterised human bladder cancer stem cells (CSCs) and attempted to identify regulatory mechanisms. Focusing on non-muscle invasive bladder cancer (NMIBC), multiple human cell lines were used to characterise SP and ABC transporter expression. In vitro and in vivo phenotypic and functional assessments of CSC behaviour were undertaken. Expression of putative CSC marker ABCG2 was assessed in clinical NMIBC samples (n = 148), and a role for MAPK signalling, a central mechanism of bladder tumourigenesis, was investigated. Results showed that the ABCG2 transporter was predominantly expressed and was up-regulated in the SP fraction by 3-fold (ABCG2(hi)) relative to the non-SP (NSP) fraction (ABCG2(low)). ABCG2(hi) SP cells displayed enrichment of stem cell markers (Nanog, Notch1 and SOX2) and a three-fold increase in colony forming efficiency (CFE) in comparison to ABCG2(low) NSP cells. In vivo, ABCG2(hi) SP cells enriched for tumour growth compared with ABCG2(low) NSP cells, consistent with CSCs. pERK was constitutively active in ABCG2(hi) SP cells and MEK inhibition also inhibited the ABCG2(hi) SP phenotype and significantly suppressed CFE. Furthermore, on examining clinical NMIBC samples, ABCG2 expression correlated with increased recurrence and decreased progression free survival. Additionally, pERK expression also correlated with decreased progression free survival, whilst a positive correlation was further demonstrated between ABCG2 and pERK expression. In conclusion, we confirm ABCG2(hi) SP enriches for CSCs in human NMIBC and MAPK/ERK pathway is a suitable therapeutic target.

Human α(2)β(1)(HI) CD133(+VE) epithelial prostate stem cells express low levels of active androgen receptor

Stem cells are thought to be the cell of origin in malignant transformation in many tissues, but their role in human prostate carcinogenesis continues to be debated. One of the conflicts with this model is that cancer stem cells have been described to lack androgen receptor (AR) expression, which is of established importance in prostate cancer initiation and progression. We re-examined the expression patterns of AR within adult prostate epithelial differentiation using an optimised sensitive and specific approach examining transcript, protein and AR regulated gene expression. Highly enriched populations were isolated consisting of stem (α₂β₁^HI CD133^+VE), transiently amplifying (α₂β₁^HI CD133^–VE) and terminally differentiated (α₂β₁^LOW CD133^–VE) cells. AR transcript and protein expression was confirmed in α₂β₁^HI CD133^+VE and CD133^–VE progenitor cells. Flow cytometry confirmed that median (±SD) fraction of cells expressing AR were 77% (±6%) in α₂β₁^HI CD133^+VE stem cells and 68% (±12%) in α₂β₁^HI CD133^–VE transiently amplifying cells. However, 3-fold lower levels of total AR protein expression (peak and median immunofluorescence) were present in α₂β₁^HI CD133^+VE stem cells compared with differentiated cells. This finding was confirmed with dual immunostaining of prostate sections for AR and CD133, which again demonstrated low levels of AR within basal CD133^+VE cells. Activity of the AR was confirmed in prostate progenitor cells by the expression of low levels of the AR regulated genes PSA, KLK2 and TMPRSS2. The confirmation of AR expression in prostate progenitor cells allows integration of the cancer stem cell theory with the established models of prostate cancer initiation based on a functional AR. Further study of specific AR functions in prostate stem and differentiated cells may highlight novel mechanisms of prostate homeostasis and insights into tumourigenesis.

Contemporaneous cell spreading and phagocytosis: magneto-resistive real-time monitoring of membrane competing processes

Adhesion and spreading of cells strongly depend on the properties of the underlying surface, which has significant consequences in long-term cell behavior adaption. This relationship is important for the understanding of both biological functions and their bioactivity in disease-related applications. Employing our magnetic lab-on-a-chip system, we present magnetoresistive-based real-time and label-free detection of cellular phagocytosis behavior during their spreading process on particle-immobilized sensor surfaces. Cell spreading experiments carried out on particle-free and particle-modified surfaces reveal a delay in spreading rate after an elapsed time of about 2.2h for particle-modified surfaces due to contemporaneous cell membrane loss by particle phagocytosis. Our associated magnetoresistive measurements show a high uptake rate at early stages of cell spreading, which decreases steadily until it reaches saturation after an average elapsed time of about 100 min. The corresponding cellular average uptake rate during the entire cell spreading process accounts for three particles per minute. This result represents a four times higher phagocytosis efficiency compared to uptake experiments carried out for confluently grown cells, in which case cell spreading is already finished and, thus, excluded. Furthermore, other dynamic cell-surface interactions at nano-scale level such as cell migration or the dynamics of cell attachment and detachment are also addressable by our magnetic lab-on-a-chip approach.

Magnetoresistive-based real-time cell phagocytosis monitoring

The uptake of large particles by cells (phagocytosis) is an important factor in cell biology and also plays a major role in biomedical applications. So far, most methods for determining the phagocytic properties rely on cell-culture incubation and end-point detection schemes. Here, we present a lab-on-a-chip system for real-time monitoring of magnetic particle uptake by human fibroblast (NHDF) cells. It is based on recording the time evolution of the average position and distribution of magnetic particles during phagocytosis by giant-magnetoresistive (GMR) type sensors. We employ particles with a mean diameter of 1.2 μm and characterize their phagocytosis-relevant properties. Our experiments at physiological conditions reveal a cellular uptake rate of 45 particles per hour and show that phagocytosis reaches saturation after an average uptake time of 27.7h. Moreover, reference phagocytosis experiments at 4°C are carried out to mimic environmental or disease related inhibition of the phagocytic behavior, and our measurements clearly show that we are able to distinguish between cell-membrane adherent and phagocytosed magnetic particles. Besides the demonstrated real-time monitoring of phagocytosis mechanisms, additional nano-biointerface studies can be realized, including on-chip cell adhesion/spreading as well as cell migration, attachment and detachment dynamics. This versatility shows the potential of our approach for providing a multifunctional platform for on-chip cell analysis.

Hunterian Lecture. Characterisation of human prostate epithelial progenitor differentiation in response to androgens

INTRODUCTION

A stem cell model of prostate cancer tumourigenesis explains progression to castration resistant prostate cancer (CRPC) and offers novel perspectives in targeting this cancer in its more advanced forms. Androgen receptor (AR) regulated pathways are central mechanisms in progression to CRPC. However, AR was thought to be lacking in prostate stem cell enriched fractions. Potential low levels of AR expression in stem cell enriched cells were investigated and potential direct effects of androgen were examined.

METHODS

Human prostate stem cell enriched populations, based on high α(2)β(1) integrin expression (α(2)β(1)(hi)), were selected from primary human prostate tissue in men undergoing transurethral prostatectomy or cystoprostatectomy. Effects on differentiation were assayed with flow cytometry using differentiation-specific markers.

RESULTS

Low levels of AR were demonstrable in α(2)β(1)(hi) cells following inhibition of the proteasome using MG132. Furthermore, a direct effect of androgen was shown in stabilising/inducing AR expression. Androgen treatment of α(2)β(1)(hi) cells was associated with the induction of differentiation using a number of differentiation-specific markers (prostatic acid phosphatase, cytokeratin 18 and AR) with increases ranging from 49% to 67% (p<0.05). These effects were blocked with the AR-specific inhibitor bicalutamide (p<0.05). These data support a role of direct androgen activity on stem cell enriched cells in the prostate and the implications of these findings are discussed.

In situ lineage tracking of human prostatic epithelial stem cell fate reveals a common clonal origin for basal and luminal cells

Stem cells accumulate mitochondrial DNA (mtDNA) mutations resulting in an observable respiratory chain defect in their progeny, allowing the mapping of stem cell fate. There is considerable uncertainty in prostate epithelial biology where both basal and luminal stem cells have been described, and in this study the clonal relationships within the human prostate epithelial cell layers were explored by tracing stem cell fate. Fresh-frozen and formalin-fixed histologically-benign prostate samples from 35 patients were studied using sequential cytochrome c oxidase (COX)/succinate dehydrogenase (SDH) enzyme histochemistry and COX subunit I immunofluorescence to identify areas of respiratory chain deficiency; mtDNA mutations were identified by whole mitochondrial genome sequencing of laser-captured areas. We demonstrated that cells with respiratory chain defects due to somatic mtDNA point mutations were present in prostate epithelia and clonally expand in acini. Lineage tracing revealed distinct patterning of stem cell fate with mtDNA mutations spreading throughout the whole acinus or, more commonly, present as mosaic acinar defects. This suggests that individual acini are typically generated from multiple stem cells, and the presence of whole COX-deficient acini suggests that a single stem cell can also generate an entire branching acinar subunit of the gland. Significantly, a common clonal origin for basal, luminal and neuroendocrine cells is demonstrated, helping to resolve a key area of debate in human prostate stem cell biology.

Multifrequency impedance measurement technique for wireless characterization of microbiological cell cultures

An impedance measurement system with probe signal frequencies up to 50 kHz with AC-probe voltages below 30 mV rms was integrated for wireless and battery-free monitoring of microbiological cell cultures. The here presented modular design and the use of state-of-the-art components greatly eases adoptions to a wide range of biotechnological applications without the need of bulky LCR-meters or potentiostats. The device had a power consumption of less than 2.5 mA at a 3.3 V single power supply and worked trouble-free within the humid environment of a cell culture incubator. Measurements on lumped RC-elements showed an error of less than 1% for absolute values and less than 1° regarding the phase of the complex impedance. The performance of sensor devices with interdigitated electrode structures for the measurement of adherent cell cultures was tested in the presence of phosphate-buffered saline solution in the humid atmosphere of an incubator for biological cell cultures.

A critical systematic review of recent clinical trials comparing open retropubic, laparoscopic and robot-assisted laparoscopic radical prostatectomy

The surgical treatment of prostate cancer has evolved rapidly, driven by technological advances that have made minimally-invasive prostatectomy feasible. The contemporary surgical approaches are laparoscopic radical prostatectomy (LRP) and robot-assisted laparoscopic radical prostatectomy (RALP). These are now considered standard modalities of treatment in urology departments across North America, Europe and centres of excellence world-wide. However, despite the widespread adoption of minimally-invasive approaches there are only a handful of robust studies directly comparing the results of these techniques with the gold standard approach of open radical prostatectomy (ORP). Of note, uncertainty remains over exactly which men with localised prostate cancer will benefit from radical treatment and the reduction of surgical side-effects is paramount in optimising outcomes. This systematic review examines the current status of minimally- invasive prostatectomy focussing on peri-operative, oncological and urogenital functional outcomes.

Characterisation of human prostate epithelial progenitor differentiation in response to androgens

INTRODUCTION

A stem cell model of prostate cancer tumourigenesis explains progression to castration resistant prostate cancer (CRPC) and offers novel perspectives in targeting this cancer in its more advanced forms. Androgen receptor (AR) regulated pathways are central mechanisms in progression to CRPC. However, AR was thought to be lacking in prostate stem cell enriched fractions. Potential low levels of AR expression in stem cell enriched cells were investigated and potential direct effects of androgen were examined.

METHODS

Human prostate stem cell enriched populations, based on high α2β1 integrin expression (α2β1hi), were selected from primary human prostate tissue in men undergoing transurethral prostatectomy or cystoprostatectomy. Effects on differentiation were assayed with flow cytometry using differentiation-specific markers.

RESULTS

Low levels of AR were demonstrable in α2β1hi cells following inhibition of the proteasome using MG132. Furthermore, a direct effect of androgen was shown in stabilising/inducing AR expression. Androgen treatment of α2β1hi cells was associated with the induction of differentiation using a number of differentiation-specific markers (prostatic acid phosphatase, cytokeratin 18 and AR) with increases ranging from 49% to 67% (p<0.05). These effects were blocked with the AR-specific inhibitor bicalutamide (p<0.05). These data support a role of direct androgen activity on stem cell enriched cells in the prostate and the implications of these findings are discussed.

Thiothymidine combined with UVA as a potential novel therapy for bladder cancer

BACKGROUND

Thiothymidine (S(4)TdR) can be incorporated into DNA and sensitise cells to DNA damage and cell death following exposure to UVA light. Studies were performed to determine if the combination of S(4)TdR and UVA could be an effective treatment for bladder cancer.

METHODS

Uptake and incorporation of S(4)TdR was determined in rat and human bladder tumour cell lines. Measures of DNA crosslinking and apoptosis were also performed. In vivo activity of the combination of S(4)TdR and UVA was investigated in an orthotopic model of bladder cancer in rats.

RESULTS

Thiothymidine (200 μM) replaced up to 0.63% of thymidine in rat and tumour bladder cancer cells. The combination of S(4)TdR (10-200 μM) and UVA (1-5 kJ m(-2)) caused apoptosis and cell death at doses that were not toxic alone. Addition of raltitrexed (Astra Zeneca, Alderley Edge, Cheshire, UK) increased the incorporation of S(4)TdR into DNA (up to 20-fold at IC(5)) and further sensitised cells to UVA. Cytotoxic effect was associated with crosslinking of DNA, at least partially to protein. Intravenous administration of S(4)TdR, in combination with UVA delivered directly to the bladder, resulted in an antitumour effect in three of five animals treated.

CONCLUSION

These data indicate that the combination of S(4)TdR and UVA has potential as a treatment for bladder cancer, and give some insight into the mechanism of action. Further work is necessary to optimise the delivery of the two components.

Wireless powered electronic sensors for biological applications

Radio frequency identification technology is used to power a novel platform of sensor devices. The employed energy harvesting system of the individual sensors enables a blanking of the radio frequency field for a defined period, while supplying the sensor electronics with a highly stable voltage. This guarantees interference free operation of the electronic circuitry during measurements. The implementation of this principle is demonstrated for a sensor system which is based on insets for state-of-the-art micro-titer-plates. Each inset is carrying electronic circuitry and an interdigitated electrode system which is acting as sensor for recording alterations of the cell metabolism. The presented sensor devices work without batteries and are designed for impedance measurements on microbiological cell cultures under physiological relevant conditions.

Phenotypic modulation of human urinary tract stroma-derived fibroblasts by transforming growth factor beta3

OBJECTIVES

Animal models have described critical roles for transforming growth factor beta (TGFbeta) isoforms in modulating urinary tract stroma phenotype. TGFbeta3 is of particular interest because it may regulate TGFbeta1 and TGFbeta2 expression, but its modulatory affect has not been so well characterized in human cells. In this study, we aim to determine whether TGFbeta3 treatment induced differentiation of human urinary tract stroma-derived fibroblasts to a smooth muscle-like phenotype.

METHODS

We established cultures of human urinary tract stroma-derived fibroblasts and studied the effects of TGFbeta3 treatment using proliferation assays, cell cycle analysis, immunocytochemistry, and Western blotting for expression of differentiation marker and downstream regulators, and fura-2 fluorescence to study the effects on intracellular calcium.

RESULTS

TGFbeta3 treatment induced proliferation that peaked at 72 hours, followed by enhanced expression of alpha-smooth muscle actin (alpha-SMA) with a maximal 3.4-fold increase at 168 hours. TGFbeta3 treatment decreased resting [Ca(2+)](i) by 70% and caused a 95% decrease in stimulated internal Ca(2+) release regulated by the sarcoplasmic/endoplasmic calcium-ATPase pump. These effects were associated with upregulation of nuclear activator of T cells -1 (NFAT), a known regulator of cell differentiation.

CONCLUSIONS

TGFbeta3 treatment causes a time-specific response in the presence of serum, whereby fibroblasts initially proliferate and subsequently differentiate to a smooth muscle-like phenotype. This sequence was associated with stabilization of [Ca(2+)](i) stores, suggesting a role in the induction of hyperplasia and reduction of contractility; phenomena associated with a number of urinary tract pathologies.

Highly sensitive passive radio frequency identification based sensor systems

A novel platform for sensor applications based on radio frequency (rf) identification technology, where passive tags are powered by the rf-field of a reader, is presented. The sophisticated energy harvesting system of the tag enables a blanking of the rf-field for a defined period, while supplying the tag electronics with a highly stable voltage and a power of 25 mW for 100 ms. During this time, span measurements can be performed without interferences of the rf-field. The presented tags work without batteries and are designed for impedance measurements on microbiological cell cultures under physiological relevant conditions as well as in harsh environments.

The RNA helicase p68 is a novel androgen receptor coactivator involved in splicing and is overexpressed in prostate cancer

The androgen receptor (AR) is a member of the nuclear steroid hormone receptor family and is thought to play an important role in the development of both androgen-dependent and androgen-independent prostatic malignancy. Elucidating roles by which cofactors regulate AR transcriptional activity may provide therapeutic advancement for prostate cancer (PCa). The DEAD box RNA helicase p68 (Ddx5) was identified as a novel AR-interacting protein by yeast two-hybrid screening, and we sought to examine the involvement of p68 in AR signaling and PCa. The p68-AR interaction was verified by colocalization of overexpressed protein by immunofluorescence and confirmed in vivo by coimmunoprecipitation in the PCa LNCaP cell line. Chromatin immunoprecipitation in the same cell line showed AR and p68 recruitment to the promoter region of the androgen-responsive prostate-specific antigen (PSA) gene. Luciferase reporter, minigene splicing assays, and RNA interference (RNAi) were used to examine a functional role of p68 in AR-regulated gene expression, whereby p68 targeted RNAi reduced AR-regulated PSA expression, and p68 enhanced AR-regulated repression of CD44 splicing (P = 0.008). Tyrosine phosphorylation of p68 was found to enhance coactivation of ligand-dependent transcription of AR-regulated luciferase reporters independent of ATP-binding. Finally, we observe increased frequency and expression of p68 in PCa compared with benign tissue using a comprehensive prostate tissue microarray (P = 0.003; P = 0.008). These findings implicate p68 as a novel AR transcriptional coactivator that is significantly overexpressed in PCa with a possible role in progression to hormone-refractory disease.