No description available.

The prostate epithelial stem cell has been proposed as the primary origin of neoplastic change in prostate cancer. However, due to a lack of specific markers, such cells have been profoundly difficult to isolate. We propose that the Hoechst 33342 dye efflux assay 'Side Population' originally developed to isolate a stem cell enriched haemopoietic stem cell population from bone marrow provides a method for identifying the cancer stem cell origin in prostatic adenocarcinoma.

No description available.

A high proportion of prostate cancers have been shown to be androgen-dependent. The biosynthesis of the androgens is catalysed by the cytochrome P450 enzyme 17[alpha]-hydroxylase/17, 20-lyase (P450[sub]17[alpha]), which is responsible for the conversion of C[sub]21 steroids (for example pregnenolone and progesterone) to the androgens (for example dehydroepiandrosterone and androstenedione respectively). The inhibition of this enzyme would therefore lead to the overall reduction in the level of androgens and thus result in an overall decrease in the stimulation of androgen-dependent cancer cells. The compounds synthesised within the current study were designed such that the compounds were able to donate a lone pair of electrons to the Fe atom within the haem group of the active site of P450[sub]17[alpha]. As such, compounds based on benzyl imidazole backbone were synthesised as the major range of compounds with a small number of phenyl alkyl imidazole based compounds synthesised in an effort to evaluate physicochemical factors such as hydrophobicity. In general, the results of the study show that of the benzyl imidazole-based compounds were weak inhibitors of P450[sub]17[alpha] in comparison to the standard compound, namely ketoconazole (3) (IC[sub]50=1.66[plus or minus]0.15[mu]M against 17,20-lyase and IC[sub]50=3.76[plus or minus]0.01[mu]M against 17[alpha]-hydroxylase). The most potent benzyl imidazole-based compounds synthesised were: 4- iodobenzyl imidazole (224) (IC[sub]50=1.58[plus or minus]0.17[mu]M against 17,20-lyase and IC[sub]50=10.06[plus or minus]0.96[mu]M against 17[alpha]-OHase); 1-(3,4-dichloro-benzyl)-1H-imidazole (215) (IC[sub]50=2.07[plus or minus]0.07[mu]M against 17,20-lyase and IC[sub]50=12.22[plus or minus]0.88[mu]M against 17[alpha]-hydroxylase); 1-(3,5-dichloro-benzyl)-1H-imidazole (216) (IC[sub]50=3.34[plus or minus]0.11[mu]M against 17,20-lyase and IC[sub]50=22.56[plus or minus]0.34[mu]M against 17[alpha]-hydroxylase); 1-(3,5-dibromo-benzyl)-1H-imidazole (221) (IC[sub]50=3.16[plus or minus]0.11[mu]M against 17,20-lyase and IC[sub]50=25.95[plus or minus]0.91[mu]M against 17[alpha]-hydroxylase). The phenyl alkyl imidazole based compounds were found to be more potent than the benzyl imidazole-based compounds and 3 and included: phenylheptyl imidazole (318) (IC[sub]50=0.10[plus or minus]0.02[mu]M against 17,20-lyase and IC[sub]50=0.32[plus or minus]0.05[mu]M against 17[alpha]-hydroxylase); phenyloctyl imidazole (321) (IC[sub]50=0.21[plus or minus]0.02[mu]M against 17,20-lyase and IC[sub]50=0.25[plus or minus]0.01[mu]M against 17[alpha]-hydroxylase); and phenylnonyl imidazole (324) (IC[sub]50=0.35[plus or minus]0.01[mu]M against 17,20-lyase and IC[sub]50=1.06[plus or minus]0.03[mu]M against 17[alpha]-hydroxylase). Consideration of the structure-activity relationship determination and the molecular modeling of the synthesised compounds using the substrate-haem complex (SHC) approach shows that the disubstituted derivatives of benzyl imidazole were able to utilise both hydrogen bonding groups which are presumed to exist at the active site of P450[sub]17[alpha]. These compounds were found to be considerably more potent than the mono-substituted derivatives, as such, it suggests that the increase in the number of interactions between the inhibitor and the enzyme is the key feature which results in the increase in potency. The inhibitory data obtained for the phenyl alkyl imidazole-based compounds show that hydrophobicity (logP) of the inhibitor plays a major role in determining the overall inhibitory activity of these compounds. As such, the study suggests that in the design of further novel inhibitors of this enzyme, the interaction with the active site and logP are two factors which would allow for the synthesis of highly potent inhibitors of this enzyme.

No description available.

No description available.

Prostate cancer (CaP) is the most common cancer in men in the UK and its incidence is increasing. The natural history of the disease is very variable, in some men progressing rapidly while in others It will run a more indolent course, in early disease localised to the prostate, radical treatment options offer potential cure however these come with considerable potential morbidity and a significant proportion of patients will relapse despite such interventions. This suggests the presence of microscopic disease beyond the prostate, not clinically detectable using current staging modalities.

No description available.

Pathogenic gain-of-function mutations associated with increased paternal age, albeit harmful to embryonic development, are paradoxically enriched in the normal testis. Evidence from previous studies indicates that these so-called paternal age-effect mutations confer a proliferative advantage to the spermatogonia in which they arise, leading to clonal expansion within the normal testis over time. Recently, spermatocytic seminoma (SS; a rare testicular germ cell tumour that occurs mainly in older men) has emerged as a key link between the processes of somatic and germline mutation (Goriely et al, Nat Genet. 41:1247-52, 2009), suggesting that the proposed clonal expansion events can in some cases lead to testicular tumourigenesis. In this thesis, I have used immunohistochemistry to seek evidence for putative clones of cells in the normal adult testis. To address this, a screening approach was developed using markers chosen from analysis of normal testicular tissues and SS. The ontogeny of OCT2 and SSX expression in human testis, from embryonic development to adulthood, identified distinct subpopulations of spermatogonia at different maturation stages. Together, these data reveal the potential of OCT2 as a novel marker of A_dark spermatogonia (human reserve spermatogonial stem cells). In parallel with these observations, two distinct types of SS characterised by differential OCT2 and SSX immunoexpression were identified, providing new evidence for heterogeneity of this tumour. This work provided the backdrop to the detailed immunohistochemical study of normal adult testis by characterising in serial sections the expression of five spermatogonial markers, MAGEA4, SSX, FGFR3, OCT2 and SAGE1, and a proliferation marker, Ki67. Independent sections were screened with predetermined criteria set to identify unusual positively-stained cellular clusters within the seminiferous tubules. Several antigenic combinations previously described in SS were observed in a subset of these clones, suggesting differing genetic origins and a possible link with early events of testicular tumourigenesis. The size (minimum number of cells) of each clonal event was estimated and its correlation with the staining pattern of the molecular markers was investigated. In summary, the data presented in this thesis convincingly identify for the first time the previously hypothesised clonal events in the testis using immunohistochemical markers. My research will pave the way for future work involving genetic analysis of microdissected cells from these putative clones, aimed at identifying the underlying mutational events thought to be present.

Lorsqu'un biomarqueur est mesuré de façon répétée au cours du suivi de patients, il est d'abord nécessaire d'établir un critère, issu du profil d'évolution longitudinal du marqueur, afin de détecter la survenue d'un événement, ou d'en prédire la gravité. Nous avons développé une méthode de modélisation robuste de données longitudinales, afin de calculer les différents critères pour les patients, et d'en comparer les performances diagnostiques ou pronostiques. Dans un second temps, il faut déterminer un seuil de ce critère quantitatif au dessus ou en dessous duquel le test diagnostique est considéré comme positif. Une méthode Bayésienne d'estimation de ce seuil et de son intervalle de crédibilité a été développée. Ce travail a été appliqué au diagnostic de persistance locale de cellules cancéreuses après traitement par ultrasons d'un cancer de la prostate. Ce diagnostic est effectué à partir des mesures répétées d'antigène spécifique de la prostate (PSA), dont le nadir a été retenu, avec différents seuils, comme meilleur critère diagnostique. Ceci permet de n'effectuer des biopsies que lorsqu'il y a de fortes chances qu'elles soient positives. / For the early diagnosis or prognosis of an event in presence of repeated measurements of a biomarker over time, it is necessary to define a criterion, stemming from the longitudinal profiles of that marker. A method was developed for a robust modelling of marker measurements, to calculate the various criteria for the patients, and compare their diagnostic or prognostic accuracies. Using the continuous criterion as a diagnostic test requires the specification of a threshold. A Bayesian method was developed to estimate this threshold and its credible interval. This method was applied to the diagnosis of local prostate cancer persistence after an ultrasound treatment. The diagnosis relies on serial measurements of prostate specific antigen (PSA), whose nadir (along with several thresholds) was found to be the best diagnostic criterion. This allows to trigger biopsy only when this biopsy is likely to be positive.