Anup Patel

Mouse DNA contamination in human tissue tested for XMRV

BackgroundWe used a PCR-based approach to study the prevalence of genetic sequences related to a gammaretrovirus, xenotropic murine leukemia virus-related virus, XMRV, in human prostate cancer. This virus has been identified in the US in prostate cancer patients and in those with chronic fatigue syndrome. However, with the exception of two patients in Germany, XMRV has not been identified in prostate cancer tissue in Europe. Most putative associations of new or old human retroviruses with diseases have turned out to be due to contamination. We have looked for XMRV sequences in DNA extracted from formalin-fixed paraffin- embedded prostate tissues. To control for contamination, PCR assays to detect either mouse mitochondrial DNA (mtDNA) or intracisternal A particle (IAP) long terminal repeat DNA were run on all samples, owing to their very high copy number in mouse cells.ResultsIn general agreement with the US prevalence, XMRV-like sequences were found in 4.8% of prostate cancers. However, these were also positive, as were 21.5% of XMRV-negative cases, for IAP sequences, and many, but not all were positive for mtDNA sequences.ConclusionsThese results show that contamination with mouse DNA is widespread and detectable by the highly sensitive IAP assay, but not always with less sensitive assays, such as murine mtDNA PCR. This study highlights the ubiquitous presence of mouse DNA in laboratory specimens and offers a means of rigorous validation for future studies of murine retroviruses in human disease.

Simultaneous combined use of flexible ureteroscopy and percutaneous nephrolithotomy to reduce the number of access tracts in the management of complex renal calculi

In a joint study between Duke University, North Carolina and London, a simultaneous combination of flexible ureteroscopy and percutaneous nephrolithotomy was used to reduce the number of access tracts required to manage complex renal calculi. This was found to be an effective method which reduced morbidity and blood loss, without increasing operating time, but without increasing stone‐free rates.

Voltage-gated sodium channel activity promotes prostate cancer metastasis in vivo

Epigenetic upregulation of voltage-gated sodium channels (VGSCs) has been reported in a number of carcinoma cell lines and tissues. Furthermore, a large body of experimental evidence suggested that functional VGSC expression enhances various in vitro cell behaviours, such as directional motility, that would be involved in the metastatic cascade. However, it is not known if VGSC activity promotes metastasis in vivo. Here, using the Copenhagen rat model of prostate cancer and blocking VGSC activity in primary tumours with tetrodotoxin, we show (1) that the number of lung metastasis is reduced by >40% and (2) that lifespan is significantly improved.

Examining the 'gold standard': a comparative critical analysis of three consecutive decades of monopolar transurethral resection of the prostate (TURP) outcomes.

Whats known on the subject? and What does the study add?

Re-constructing masculinity following radical prostatectomy for prostate cancer.

Prostate cancer is common in older men. Surgical treatment involving removal of the prostate can result in temporary or permanent erectile dysfunction (ED) and incontinence and have a major impact on mens masculine identity. Seven men were interviewed about their experiences and concerns following prostatectomy, and the transcripts were analysed employing Foucauldian Discourse Analysis to identify the ways in which they constructed their masculinity. Participants drew upon four main discourses when discussing the impact of surgical treatment on their sense of masculinity: masculine identity and sexual activity, ED as a normative experience, mental resilience and vulnerability. Penetrative sex was constructed as central to a masculine identity, but inability to achieve this was normalised in terms of the ageing process. Stereotypically masculine qualities of emotional control and rationality were drawn on in describing their reaction to the diagnosis and treatment of cancer but they also experienced a new-found sense of physical vulnerability. The findings are discussed in terms of their implications for the clinical management of ED post-surgery and helping men adjust to life following treatment.

Transurethral electrovaporization and vapour-resection of the prostate: an appraisal of possible electrosurgical alternatives to regular loop resection.

Within the past decade, several alternatives to loop resection have been introduced into urological practice that have sought to deliver either topical or interstitial heat to obstructive prostatic tissue. The tissue effects of heat are governed by the maximum temperature achieved, the total duration for which the temperature is sustained and the temperature rise time (the rate of increase to the maximum temperature). Tissue is coagulated when the temperature rise is slow and the thermal dose is low. In contrast, a rapid temperature rise to >100uC causes a loss of intracellular water as it boils away. Under these conditions, the power density of the applied energy governs whether cells are desiccated, carbonized or vaporized. A low power density results in cell death by desiccation and carbonization, with delayed sloughing, while a high power density vaporizes cells, producing an instant tissue defect. Transurethral electrovaporization (TUEVAP) and vapour-resection (TUEVRP) of the prostate are new treatments developed through modi®cations of conventional electrosurgical tissue desiccation, using innovative electrode design. They offer the prospect of reduced bleeding and lower morbidity from ̄uid absorption in patients with bothersome LUTS associated with BPH. In clinical practice, effective prostatic electrovaporization in ̄uid depends on various factors, the most important being the active electrode con®guration, the power output characteristics of the radiofrequency (RF) generator and the way in which electrical energy is applied to the tissue by the operator.

Repression of androgen receptor activity by HEYL, a third member of the hairy/enhancer-of-split-related family of notch effectors

The Hairy/Enhancer-of-split-related with YRPW-like motif (HEY) family of proteins are transcriptional repressors and downstream effectors of Notch signaling. We previously reported that HEY1 and HEY2 selectively repress androgen receptor (AR) signaling in mammalian cell lines and have shown that in human tissue HEY1 is excluded from the nuclei in prostate cancer but not benign prostatic hyperplasia. We have now characterized a third member of this family, HEYL, which is a more potent repressor of AR activity. HEYL interacted with and repressed AR activation function-1 domain and competitively inhibited SRC1e activation of AR transcriptional activity. Using a cell line inducibly expressing exogenous HEYL, we showed that HEYL represses endogenous AR-regulated genes and reduces androgen-dependent prostate cancer cell growth. Using a trans-repression assay, we identified both trichostatin-sensitive and -insensitive domains within HEYL; however, analysis of endogenous AR target genes suggested that HEYL represses AR activity through histone deacetylase I/II-independent mechanisms. Immunohistochemical analyses of tissue indicated that, in a fashion similar to that previously reported for HEY1, HEYL is excluded from the nuclei in prostate cancer but not adjacent benign tissue. This suggests that nuclear exclusion of HEY proteins may be an important step in the progression of prostate cancer.

The role of endoscopy in the management of patients with upper urinary tract transitional cell carcinoma

Tumours of the renal pelvis make up 10% of all renal tumours and 5% of urothelial tumours, while 1±2% of all TCCs arise from the ureter. TCCs constitute < 90% of primary urothelial tumours of the upper urinary tract (UUT), with squamous cell carcinomas (1±7%) and adenocarcinomas (<1%) accounting for the remainder. Bilateral involvement by TCC may occur synchronously or metachronously in 2±4% of patients because of the propensity for polychronotropism, but in higher proportions in those with occupational bladder cancer. The distal ureter is the most common site (73%) of ureteric tumours [1]. The incidence of subsequent bladder cancer after previous UUT-TCC is 30±50%, but increases to 75% when there is multifocal disease in the renal pelvis and ureter. UUT-TCCs have aetiological and pathological characteristics similar to those of bladder TCCs [1]. Most UUTTCCs occur in men and are more common in Caucasians than in Blacks. The most important association is smoking [2]. Analgesic/phenacetin abuse, and its association with renal papillary necrosis, have been considered independent and synergistic risk factors [3], although apparently they may not be as important as was originally thought [4]. Occupational risk factors appear to be similar to those for bladder cancer. Acrolein, which is the metabolite of cyclophosphamide [5] and ifosphamide, appears to increase the risk of UUT-TCCs in a similar way to bladder TCC, giving aggressive and highgrade tumours. In the Balkan states of central Europe, where there are regions affected by endemic nephropathy [6], there is a 100-fold greater incidence of UUT-TCCs, but these tend to be of lower stage and grade than those encountered elsewhere. The categorization of UUT-TCCs follows the TNM system (.Table 1) [7].

The intercellular adhesion molecule, cadherin-10, is a marker for human prostate luminal epithelial cells that is not expressed in prostate cancer

During the normal turnover of prostate epithelium, stem cells in the basal cell layer produce an intermediate cell population that gives rise to fully differentiated secretory luminal cells. This process is extensively studied in relation to the development of prostate disease, in particular, to elucidate the origin and nature of prostate cancer. We previously showed that the mRNA of a poorly characterised intercellular adhesion molecule, cadherin-10, is strongly expressed in human prostate. Using anticadherin-10 antibodies, immunohistochemistry, and confocal microscopy, we have examined the pattern of cadherin-10 expression in relation to human prostate epithelial differentiation markers (E-cadherin, CD44, and cytokeratins (CK) 14, 18 and 19) in archival paraffin-embedded and fixed–frozen histopathological specimens in individual and serial sections. In non-neoplastic prostate, E-cadherin is expressed by all basal and luminal epithelial cells, while cadherin-10 is variably expressed in luminal cells where it is colocalised with E-cadherin at basolateral plasma membranes. Cadherin-10 is absent in CK14- and/or CD44-positive basal cells, but is expressed in CK18-positive luminal cells (differentiated secretory cells), a subset of CK19-positive intermediate/luminal cells, but not CK19-positive basal cells. Small foci of prostate cancer express E-cadherin, CK19 and CK18, but cadherin-10 expression is low or undetectable. These findings suggest that the expression of cadherin-10 is associated with the later stages of differentiation of luminal secretory cells, indicating a specific role in secretory cell terminal differentiation. While prostate cancer cells express secretory cell markers (eg, CK18, prostate-specific antigen) and the more generally expressed E-cadherin, their failure to express cadherin-10 further emphasises a role for this cadherin in normal prostate organisation and function.

Adjuvant Sunitinib for High-risk Renal Cell Carcinoma After Nephrectomy: Subgroup Analyses and Updated Overall Survival Results

BACKGROUND Adjuvant sunitinib significantly improved disease-free survival (DFS) versus placebo in patients with locoregional renal cell carcinoma (RCC) at high risk of recurrence after nephrectomy (hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.59-0.98; p=0.03). OBJECTIVE To report the relationship between baseline factors and DFS, pattern of recurrence, and updated overall survival (OS). DESIGN, SETTING, AND PARTICIPANTS Data for 615 patients randomized to sunitinib (n=309) or placebo (n=306) in the S-TRAC trial. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Subgroup DFS analyses by baseline risk factors were conducted using a Cox proportional hazards model. Baseline risk factors included: modified University of California Los Angeles integrated staging system criteria, age, gender, Eastern Cooperative Oncology Group performance status (ECOG PS), weight, neutrophil-to-lymphocyte ratio (NLR), and Fuhrman grade. RESULTS AND LIMITATIONS Of 615 patients, 97 and 122 in the sunitinib and placebo arms developed metastatic disease, with the most common sites of distant recurrence being lung (40 and 49), lymph node (21 and 26), and liver (11 and 14), respectively. A benefit of adjuvant sunitinib over placebo was observed across subgroups, including: higher risk (T3, no or undetermined nodal involvement, Fuhrman grade ≥2, ECOG PS ≥1, T4 and/or nodal involvement; hazard ratio [HR] 0.74, 95% confidence interval [CI] 0.55-0.99; p=0.04), NLR ≤3 (HR 0.72, 95% CI 0.54-0.95; p=0.02), and Fuhrman grade 3/4 (HR 0.73, 95% CI 0.55-0.98; p=0.04). All subgroup analyses were exploratory, and no adjustments for multiplicity were made. Median OS was not reached in either arm (HR 0.92, 95% CI 0.66-1.28; p=0.6); 67 and 74 patients died in the sunitinib and placebo arms, respectively. CONCLUSIONS A benefit of adjuvant sunitinib over placebo was observed across subgroups. The results are consistent with the primary analysis, which showed a benefit for adjuvant sunitinib in patients at high risk of recurrent RCC after nephrectomy. PATIENT SUMMARY Most subgroups of patients at high risk of recurrent renal cell carcinoma after nephrectomy experienced a clinical benefit with adjuvant sunitinib. TRIAL REGISTRATION ClinicalTrials.gov NCT00375674.