Richard J. Bryant

Changes in circulating microRNA levels associated with prostate cancer

Background:The aim of this study was to investigate the hypothesis that changes in circulating microRNAs (miRs) represent potentially useful biomarkers for the diagnosis, staging and prediction of outcome in prostate cancer.Methods:Real-time polymerase chain reaction analysis of 742 miRs was performed using plasma-derived circulating microvesicles of 78 prostate cancer patients and 28 normal control individuals to identify differentially quantified miRs.Results:A total of 12 miRs were differentially quantified in prostate cancer patients compared with controls, including 9 in patients without metastases. In all, 11 miRs were present in significantly greater amounts in prostate cancer patients with metastases compared with those without metastases. The association of miR-141 and miR-375 with metastatic prostate cancer was confirmed using serum-derived exosomes and microvesicles in a separate cohort of patients with recurrent or non-recurrent disease following radical prostatectomy. An analysis of five selected miRs in urine samples found that miR-107 and miR-574-3p were quantified at significantly higher concentrations in the urine of men with prostate cancer compared with controls.Conclusion:These observations suggest that changes in miR concentration in prostate cancer patients may be identified by analysing various body fluids. Moreover, circulating miRs may be used to diagnose and stage prostate cancer.

Predicting High-Grade Cancer at Ten-Core Prostate Biopsy Using Four Kallikrein Markers Measured in Blood in the ProtecT Study

Background: Many men with elevated prostate-specific antigen (PSA) levels in serum do not have aggressive prostate cancer and undergo unnecessary biopsy. Retrospective studies using cryopreserved serum suggest that four kallikrein markers can predict biopsy outcome. Methods: Free, intact and total PSA, and kallikrein-related peptidase 2 were measured in cryopreserved blood from 6129 men with elevated PSA (≥3.0ng/mL) participating in the prospective, randomized trial Prostate Testing for Cancer and Treatment. Marker levels from 4765 men providing anticoagulated plasma were incorporated into statistical models to predict any-grade and high-grade (Gleason score ≥7) prostate cancer at 10-core biopsy. The models were corrected for optimism by 10-fold cross validation and independently validated using markers measured in serum from 1364 men. All statistical tests were two-sided. Results: The four kallikreins enhanced prostate cancer detection compared with PSA and age alone. Area under the curve (AUC) for the four kallikreins was 0.719 (95% confidence interval [CI] = 0.704 to 0.734) vs 0.634 (95% CI = 0.617 to 0.651, P < .001) for PSA and age alone for any-grade cancer, and 0.820 (95% CI = 0.802 to 0.838) vs 0.738 (95% CI = 0.716 to 0.761) for high-grade cancer. Using a 6% risk of high-grade cancer as an illustrative cutoff, for 1000 biopsied men with PSA levels of 3.0ng/mL or higher, the model would reduce the need for biopsy in 428 men, detect 119 high-grade cancers, and delay diagnosis of 14 of 133 high-grade cancers. Models exhibited excellent discrimination on independent validation among men with only serum samples available for analysis. Conclusions: A statistical model based on kallikrein markers was validated in a large prospective study and reduces unnecessary biopsies while delaying diagnosis of high-grade cancers in few men.

Vertical Variation in Pollen Abundance in North-Central London

SummaryPollen data from three samplers located at heights of 0.5m, 10m and 55 m were used to investigate vertical differences in pollen abundance in North-Central London. Weekly accumulative counts for all pollen types were collected from February to September 1988. Distinct variations in abundance between the sites were recorded for some pollen taxa. For example,Gramineae recorded greater abundance at the higher sampling position. Other pollen types, includingPlatanus, were recorded at consistently greater abundance at the 10 m height compared to the 55 m level. Significant differences between the pollen counts at these two heights are discussed in relation to pollen source area, the specific gravity of the pollen grain, airflow patterns of the urban area and the weather conditions affecting pollen dispersal. Tracer experiments using Lycopodium spores were employed to investigate dispersal patterns to all three sampling heights. The results from these trials are used to assist in the interpretation of data from the depositional samplers. The study reported in this paper forms part of a wider survey of 14 sampling sites examining spatial variations in pollen abundance.

Emerging PSA-Based Tests to Improve Screening

This article updates advances in prostate cancer screening based on prostate-specific antigen, its derivatives, and human kallikrein markers. Many men are diagnosed with indolent disease not requiring treatment. Although there is evidence of a survival benefit from screening, the numbers needed to screen and treat remain high. There is risk of exposing men to the side effects of treatment for nonthreatening disease. A screening test is needed with sufficiently good performance characteristics to detect disease at an early stage so treatment may be offered with curative intent, while reducing the number of negative or unnecessary biopsies.

Nuclear iASPP may facilitate prostate cancer progression

One of the major challenges in prostate cancer (PCa) research is the identification of key players that control the progression of primary cancers to invasive and metastatic disease. The majority of metastatic PCa express wild-type p53, whereas loss of p63 expression, a p53 family member, is a common event. Here we identify inhibitor of apoptosis-stimulating protein of p53 (iASPP), a common cellular regulator of p53 and p63, as an important player of PCa progression. Detailed analysis of the prostate epithelium of iASPP transgenic mice, iASPPΔ8/Δ8 mice, revealed that iASPP deficiency resulted in a reduction in the number of p63 expressing basal epithelial cells compared with that seen in wild-type mice. Nuclear and cytoplasmic iASPP expression was greater in PCa samples compared with benign epithelium. Importantly nuclear iASPP associated with p53 accumulation in vitro and in vivo. A pair of isogenic primary and metastatic PCa cell lines revealed that nuclear iASPP is enriched in the highly metastatic PCa cells. Nuclear iASPP is often detected in PCa cells located at the invasive leading edge in vivo. Increased iASPP expression associated with metastatic disease and PCa-specific death in a clinical cohort with long-term follow-up. These results suggest that iASPP function is required to maintain the expression of p63 in normal basal prostate epithelium, and nuclear iASPP may inactivate p53 function and facilitate PCa progression. Thus iASPP expression may act as a predictive marker of PCa progression.Cell Death and Disease (2014) 5, e1492; doi:10.1038/cddis.2014.456; published online 23 October 2014

The incidence of fungal spores in the ambient air and inside homes: Evidence from London

Little research has been carried out in London concerning fungal spore prevalence yet this information may help to elucidate geographical patterns of asthma and hay fever. Although many types of spore reach peak concentrations outdoors in late-summer, the incidences in the indoor environment may be more important through the winter because of heating and poor ventilation. Daily average concentrations of fungal spores in the ambient atmosphere were monitored with a Burkard volumetric spore trap on an exposed roof in North London from autumn 1991 until the summer of 1992. Indoor spore measurements were taken in 19 homes in the vicinity through the winter months, both by direct air sampling using a portable Burkard sampler and by dust culture. Trends in the occurrence and concentrations of fungal spores indoors and outdoors were examined. Relationships between the abundance of selected allergenic fungi and features of the houses were analysed including age of dwelling, dampness, cleanliness and presence of pets.Aspergillus andPenicillium were the most frequently occurring spore types in the homes. Overall, high spore incidence was associated with dampness and dust accumulation. The outdoor spore samples revealed generally low concentrations through the winter until March when concentrations of many types includingCladosporium, Epicoccum andAlternaria increased in abundance in response to the warmer weather. Even during the late-spring and early-summer, concentrations of most fungal spores were notably below those reported for rural sites.

Flexible cystoscopy findings in patients investigated for profound lower urinary tract symptoms, recurrent urinary tract infection, and pain.

BACKGROUND AND PURPOSE The National Institute of Clinical Excellence published guidelines in 2010 recommending the use of cystoscopy to investigate profound lower urinary tract symptoms (pLUTS), recurrent urinary tract infection (rUTI), and pain in men. Currently, there are no equivalent guidelines for women. We aimed to examine the diagnostic performance of flexible cystoscopy (FC) when it is used in this context in both men and women. PATIENTS AND METHODS Results of all outpatient FCs undertaken in our department between April 2009 and March 2010 were examined retrospectively. Patients undergoing FC for the investigation of pLUTS, rUTI, or pain were included. Diagnostic performance was calculated, which was defined as the number of patients receiving a diagnosis of a clinically relevant abnormality at FC divided by the total number of patients undergoing FC for this indication. RESULTS Of the 1809 patients who underwent FC during the study period, 113 underwent FC to investigate pLUTS, rUTI, or pain. Diagnostic performance was 11.5% (n=13), being 11.4%, 19.2%, and 0% in those with pLUTS, rUTI, and pain, respectively. Bladder cancer was diagnosed in one (0.9%) patient who underwent FC to investigate pLUTS but also had nonvisible hematuria. Urethral stricture was diagnosed in nine (8.0%) cases and intravesical calculi in four (3.5%) cases. CONCLUSION Clinically relevant abnormalities were found in 11.5% of patients with pLUTS, rUTI, or pain, supporting recently published NICE guidelines recommending cystoscopy in patients with pLUTS or rUTI. Of the 17 patients who were investigated for pain, none was found to have clinically relevant abnormalities; further studies are needed to define the clinical utility of FC in these cases.

The genomic diversity of prostate cancer: our Achilles heel explored.

In this month’s issue of European Urology, Lindberg and colleagues explored the monoclonality of a case of metastatic prostate cancer (PCa) using exome sequencing of lymph node metastases and matched primary PCa tissue [1]. This was undertaken as a follow-up to their recently published exome-sequencing analysis of a much larger number of samples [2]. The authors elegantly demonstrated that none of the somatic mutations identified within the lymph nodemetastases from an individual patient matched those originally identified in the initial primary cancer sample. Consequently, the analysis was expanded to include multiple distinct areas of laser-microdissected primary PCa samples from the same patient. Intriguingly, this revealed that the metastatic clones most closely matched a seeding focus of primary intraductal PCa, a histologic variant known to be associated with poor outcome [3]. This new evidence supports the notion that metastases arise as a consequence of the development of a lethal clone of cells within the primary tumour [4,5] andmay not always be a late event [6]. This latest study provides new insight into themolecular heterogeneity of PCa and emphasises the importance of thorough tissue sampling, along with detailed genetic analysis of high-quality specimens, to better understand the linear cancer evolution and to design precision-driven therapeutic approaches to improve patient outcomes [1]. The interesting conundrum in the work described by Lindberg and colleagues is that the tumour had metastasised from a clone growingwithin ducts rather than clonal areas showing locally invasive behaviour, such as foci of extraprostatic extension or seminal vesicle invasion, where one might postulate metastasis would arise. There is indeed increasing interest in the prognostic significance of intraductal carcinoma as well as cribriform invasive lesions with elements of Gleason pattern 4 [7]. Molecularly, histologically, and clinically, PCa is a very heterogeneous disease, and many patients harbour several independent foci of malignancy within the prostate [8]. The past decade has seen an increased focus of research activity to identify germline mutations and single nucleotide polymorphisms associated with clinically aggressive disease. Despite some success in identifying such lesions, this approach has not hitherto delivered any clinical benefit. It is likely that the characterisation of somatic mutations within individual PCa cases will yield a tangible clinical benefit in terms of risk stratification of disease or prediction of outcome from treatment with targeted therapies. Further research is needed in this area before this approach can be incorporated reliably into standard urologic practice. Significant advances are being made in understanding the molecular drivers of castration-resistant PCa [9], providing greater hope that novel agents can be developed to treat men with this lethal form of disease. Despite these advances, the best hopes for cure of men with localised PCa, without overtreatment, involve precision medicine with accurate profiling of each individual malignancy, thorough molecular evaluation to understand its potential aggressiveness and behaviour, and subsequent optimisation of clinical management based on risk calculation. The genomic diversity of PCa is emerging as our Achilles heel in managing the disease, and our definition of significant versus insignificant PCa is increasingly being recognised as inadequate [10]. There is a large reservoir of latent PCawithin the general population of adult men, and a EU RO P E AN URO LOGY 6 7 ( 2 0 1 5 ) 8 2 3 – 8 2 4

Novel biomarkers for the detection of prostate cancer.

Prostate-specific antigen (PSA) is widely used as a biomarker in the detection of prostate cancer and for decision making regarding treatment options, response to therapy, and clinical follow-up. Despite its widespread use, it is well recognised that PSA has suboptimal performance as a screening tool due to poor specificity, resulting in high negative biopsy rates and potential ‘over-diagnosis’ and ‘over-treatment’ of clinically insignificant cancers. In particular, PSA does not reliably distinguish either cancer from benign prostatic conditions, or ‘clinically significant’ from ‘indolent cancers’, and it is inaccurate in predicting disease burden and response to treatment. There is an urgent demand for novel biomarkers to address these clinical needs. This article provides an update on the novel candidate biomarkers in development, which have shown potential for improving the detection of clinically significant cases of this malignancy.

TOPK modulates tumour-specific radiosensitivity and correlates with recurrence after prostate radiotherapy

Background:Tumour-specific radiosensitising treatments may enhance the efficacy of radiotherapy without exacerbating side effects. In this study we determined the radiation response following depletion or inhibition of TOPK, a mitogen-activated protein kinase kinase family Ser/Thr protein kinase that is upregulated in many cancers.Methods:Radiation response was studied in a wide range of cancer cell lines and normal cells using colony formation assays. The effect on cell cycle progression was assessed and the relationship between TOPK expression and therapeutic efficacy was studied in a cohort of 128 prostate cancer patients treated with radical radiotherapy.Results:TOPK knockdown did not alter radiation response in normal tissues, but significantly enhanced radiosensitivity in cancer cells. This result was recapitulated in TOPK knockout cells and with the TOPK inhibitor, OTS964. TOPK depletion altered the G1/S transition and G2/M arrest in response to radiation. Furthermore, TOPK depletion increased chromosomal aberrations, multinucleation and apoptotic cell death after irradiation. These results suggest a possible role for TOPK in the radiation-induced DNA damage checkpoints. These findings have clinical relevance, as elevated TOPK protein expression was associated with poorer clinical outcomes in prostate cancer patients treated with radical radiotherapy.Conclusions:This study demonstrates that TOPK disruption may cause tumour-specific radiosensitisation in multiple different tumour types.