Rakesh Heer

The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle-on-Tyne, England, United Kingdom

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Publications (35)145.87 Total impact

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    ABSTRACT: Abstract 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.
    Renal Failure 09/2013; · 0.94 Impact Factor
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    ABSTRACT: Background:Evidence increasingly supports that prostate cancer is initiated by the malignant transformation of stem cells (SCs). Furthermore, many SC-signalling pathways are shown to be shared in prostate cancer. Therefore, we planned transcriptome characterisation of adult prostate SCs as a strategy to consider new targets for cancer treatment.Methods:Intuitive pathway analysis was used for putative target discovery in 12 matched selections of human prostate SCs, transiently amplifying cells and terminally differentiated cells. These were pooled into three groups according to the stage of differentiation for mRNA microarray analysis. Targets identified were validated using uncultured primary tissue (n=12), functional models of prostate cancer and a tissue microarray consisting of benign (n=42) and malignant prostate (n=223).Results:A deficiency in class 1 UDP glucuronosyltransferase (UGT) enzymes (UGT1A) was identified in prostate SCs, which are involved in androgen catabolism. Class 1 UGT enzyme expression was also downregulated in cancer SCs and during progression to metastatic castration-resistant prostate cancer (CRPC). Reduction of UGT1A expression in vitro was seen to improve cell survival and increase androgen receptor (AR) activity, as shown by upregulation of prostate-specific antigen expression.Interpretation:Inactivation of intracellular androgen catabolism represents a novel mechanism to maintain AR activity during CRPC.British Journal of Cancer advance online publication, 23 July 2013; doi:10.1038/bjc.2013.399 www.bjcancer.com.
    British Journal of Cancer 07/2013; · 5.08 Impact Factor
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    ABSTRACT: 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. 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. 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. Increased PSA during UTI appears protective against rUTI and in vitro is linked to proteolysis of WFDC proteins supporting enhanced prostate innate defences. Prostate. © 2013 Wiley Periodicals, Inc.
    The Prostate 07/2013; · 3.84 Impact Factor
  • European Urology 06/2013; · 10.48 Impact Factor
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    ABSTRACT: Background: In comparatively socioeconomically deprived areas male cancer mortality is often above the national average. Given this, we explored the pattern of presentation and outcomes of men with conventional clear cell renal cell carcinoma (CCRCC) undergoing nephrectomy at a North East of England regional tertiary referral centre.
    Journal of Clinical Urology. 05/2013; 6(3):158-163.
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    ABSTRACT: 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.
    Journal of Clinical Urology. 05/2013; 6(3):194-196.
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    ABSTRACT: BACKGROUND: Primary culture and animal and cell-line models of prostate and bladder development have limitations in describing human biology, and novel strategies that describe the full spectrum of differentiation from foetal through to ageing tissue are required. Recent advances in biology demonstrate that direct reprogramming of somatic cells into pluripotent embryonic stem cell (ESC)-like cells is possible. These cells, termed induced pluripotent stem cells (iPSCs), could theoretically generate adult prostate and bladder tissue, providing an alternative strategy to study differentiation. OBJECTIVE: To generate human iPSCs derived from normal, ageing, human prostate (Pro-iPSC), and urinary tract (UT-iPSC) tissue and to assess their capacity for lineage-directed differentiation. DESIGN, SETTING, AND PARTICIPANTS: Prostate and urinary tract stroma were transduced with POU class 5 homeobox 1 (POU5F1; formerly OCT4), SRY (sex determining region Y)-box 2 (SOX2), Kruppel-like factor 4 (gut) (KLF4), and v-myc myelocytomatosis viral oncogene homolog (avian) (MYC, formerly C-MYC) genes to generate iPSCs. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The potential for differentiation into prostate and bladder lineages was compared with classical skin-derived iPSCs. The student t test was used. RESULTS AND LIMITATIONS: Successful reprogramming of prostate tissue into Pro-iPSCs and bladder and ureter into UT-iPSCs was demonstrated by characteristic ESC morphology, marker expression, and functional pluripotency in generating all three germ-layer lineages. In contrast to conventional skin-derived iPSCs, Pro-iPSCs showed a vastly increased ability to generate prostate epithelial-specific differentiation, as characterised by androgen receptor and prostate-specific antigen induction. Similarly, UT-iPSCs were shown to be more efficient than skin-derived iPSCs in undergoing bladder differentiation as demonstrated by expression of urothelial-specific markers: uroplakins, claudins, and cytokeratin; and stromal smooth muscle markers: α-smooth-muscle actin, calponin, and desmin. These disparities are likely to represent epigenetic differences between individual iPSC lines and highlight the importance of organ-specific iPSCs for tissue-specific studies. CONCLUSIONS: IPSCs provide an exciting new model to characterise mechanisms regulating prostate and bladder differentiation and to develop novel approaches to disease modelling. Regeneration of bladder cells also provides an exceptional opportunity for translational tissue engineering.
    European Urology 04/2013; · 10.48 Impact Factor
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    ABSTRACT: 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.
    Drug Design, Development and Therapy 03/2013; 2013:7:167-174. · 3.49 Impact Factor
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    ABSTRACT: 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.
    Nucleic Acids Research 02/2013; · 8.28 Impact Factor
  • Nucleic Acids Research 02/2013; · 8.28 Impact Factor
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    ABSTRACT: The Kattan nomogram has been used in renal cell cancer to predict progression-free survival after nephrectomy. Tumor-nodes-metastasis staging is essential for the calculation of this score. The effect of the recent 2010 revision to the tumor-nodes-metastasis classification on the predictive ability of the Kattan nomogram was studied. All patients having radical nephrectomy for renal cell cancer in the 5-year period of 2004-2008 at a tertiary referral center were included. Pathological and radiological records were reviewed to identify tumor-nodes-metastasis stage (2002 and 2010 classifications). Kattan scores were calculated for the 2002 and 2010 tumor-nodes-metastasis stages, and the effect on survival predictions were compared with actual outcomes. A total of 291 patients with non-metastatic renal cell cancer were identified. Revision of the tumor-nodes-metastasis staging from the 2002 to 2010 classification resulted in an increase in the number of patients with stage pT3a (from 30 to 75), a reduction in the patients with stage pT3b (from 57 to 10) and a small increase in stage pT4 cases (1 to 3). This altered the proportion of patients in the Kattan prognostic of "good" (from 61% to 69%), "intermediate" (from 29% to 22%) and "poor" (from 10% to 8%). The overall median predicted 5-year progression-free survival was 79.8% with 2002 tumor-nodes-metastasis, and 81.8% with 2010 tumor-nodes-metastasis. Actual 5-year progression-free survival was 83.0%, which was not significantly different from that predicted using either tumor-nodes-metastasis classification (P = 0.66). On comparing the new 2010 and old 2002 tumor-nodes-metastasis classification in our cohort, we showed the predictive ability of the Kattan nomogram remained unaltered.
    International Journal of Urology 04/2012; 19(8):773-6. · 1.73 Impact Factor
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    ABSTRACT: Background We reviewed the empirical use of antibiotics in patients with secondary haemorrhage following transurethral resection of bladder tumour.
    British Journal of Medical and Surgical Urology 03/2012;
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    ABSTRACT: The TNM classification for renal cell cancer (RCC) should accurately predict and assign prognostic information for patients. In this study the recent 2010 revision to the TNM classification was compared with the previous 2002 classification with regard to survival outcomes. All patients having radical nephrectomy for RCC in the 5-year period 2004-8 at a tertiary referral centre were included. Pathological and radiological records were reviewed to identify TNM stage (2002 and 2010 classification) and survival data were captured. 345 patients with RCC were identified. Based on the 2002 TNM staging system and using outcomes in T1 staged tumours as a baseline, statistically significant differences in disease-specific survival were noted between patients with T1 and T3b tumours (log rank p<0.001) but not between those with T1 and T3a tumours (p=0.33). However, when tumour stage was reassigned according to the 2010 classification, patients with T3a tumours were also found to do statistically worse than T1 staged disease (p<0.001). In our cohort, the new 2010 TNM reclassification of T3 tumours showed better correlation with predicting worsening outcomes compared with localised disease.
    Journal of clinical pathology 01/2012; 65(4):367-71. · 2.43 Impact Factor
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    ABSTRACT: 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 (α(2)β(1) (HI) CD133(+VE)), transiently amplifying (α(2)β(1) (HI) CD133(-VE)) and terminally differentiated (α(2)β(1) (LOW) CD133(-VE)) cells. AR transcript and protein expression was confirmed in α(2)β(1) (HI) CD133(+VE) and CD133(-VE) progenitor cells. Flow cytometry confirmed that median (±SD) fraction of cells expressing AR were 77% (±6%) in α(2)β(1) (HI) CD133(+VE) stem cells and 68% (±12%) in α(2)β(1) (HI) CD133(-VE) transiently amplifying cells. However, 3-fold lower levels of total AR protein expression (peak and median immunofluorescence) were present in α(2)β(1) (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.
    PLoS ONE 01/2012; 7(11):e48944. · 3.73 Impact Factor
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    ABSTRACT: 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.
    PLoS ONE 01/2012; 7(11):e50690. · 3.73 Impact Factor
  • BRITISH JOURNAL OF SURGERY; 01/2012
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    ABSTRACT: 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.
    The Journal of Pathology 10/2011; 225(2):181-8. · 7.59 Impact Factor
  • R Heer
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    ABSTRACT: 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. 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. 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.
    Annals of The Royal College of Surgeons of England 09/2011; 93(6):424-8. · 1.33 Impact Factor
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    ABSTRACT: 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. 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. 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. 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.
    British Journal of Cancer 06/2011; 104(12):1869-76. · 5.08 Impact Factor
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    ABSTRACT: 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.
    Reviews on Recent Clinical Trials 04/2011; 6(3):241-9. · 1.07 Impact Factor

Publication Stats

275 Citations
145.87 Total Impact Points

Institutions

  • 2010–2013
    • The Newcastle upon Tyne Hospitals NHS Foundation Trust
      • Department of Urology
      Newcastle-on-Tyne, England, United Kingdom
  • 2004–2013
    • Newcastle University
      • Northern Institute for Cancer Research
      Newcastle-on-Tyne, England, United Kingdom
  • 2011
    • Northern Institute For Cancer Research
      Newcastle-on-Tyne, England, United Kingdom