Chez les hommes, le cancer de la prostate est, au niveau mondial, le 2ème cancer le plus diagnostiqué et le 5ème cancer le plus létal. Lorsqu'il est localisé à la prostate, il est principalement traité par prostatectomie ou radiothérapie. Cependant, entre 27 et 53% des patients traités à ce stade développeront éventuellement une récidive. L'hormonothérapie qui vise à réduire l'effet des androgènes sur le cancer, permet d'augmenter significativement la survie de ces patients. Par contre, ces cancers deviendront irrémédiablement résistants à la castration puis évolueront vers la forme métastatique pour laquelle il n'existe aucun traitement curatif. Ainsi de nouvelles thérapies sont nécessaires pour augmenter la survie de ces patients. Un nombre important d'études visant le développement d'immunothérapies du cancer de la prostate ont vu le jour au cours des dernières années. Ces études ont mené entres autres au développement du Sipuleucel-T, la première immunothérapie approuvée pour le traitement du cancer de la prostate, ainsi qu'à l'étude de l'effet antitumoral des inhibiteurs de points de contrôle immunologiques. Ces traitements, principalement testés sur des cancers avancés, ont montré des effets très limités et dans certains cas, des effets indésirables importants. Plusieurs études soulignent l'importance d'administrer les traitements plus tôt dans le cours de la maladie et suggèrent que l'administration locale de combinaisons de molécules immunomodulatrices pourrait être efficace tout en limitant les effets indésirables. L'objectif principal de mon projet était de développer une nouvelle approche immunothérapeutique basée sur l'utilisation du vecteur adénoviral PCA3-TSTA permettant l'expression ciblée à la tumeur de molécules immunostimulatrices. L'expression ciblée à la tumeur est réalisée grâce à la spécificité du promoteur de l'ARN long non-codant PCA3 humain, qui est à ce jour le biomarqueur le plus spécifique du cancer de la prostate, ainsi que l'amplification de l'activité transcriptionnelle par le système TSTA. Ces approches immunothérapeutiques ont été testées dans le modèle murin immunocompétent de cancer de la prostate TRAMP-C2. Dans un premier temps, nous avons montré chez des souris portant des tumeurs TRAMP-C2, la spécificité tumorale et l'activité transcriptionnelle in vivo pendant au moins 21 jours de l'adénovirus PCA3-TSTA codant pour la luciférase. Nous avons ensuite construit et testé des adénovirus PCA3-TSTA codant pour les formes murines de mGM-CSF, mIL-17A ou mIL-12. Seul le traitement précoce de tumeurs TRAMP-C2 par l'adénovirus PCA3-TSTA-mIL-12 a résulté en une régression tumorale complète chez 100% des souris traitées. A un stade plus avancé, ce traitement a induit un ralentissement significatif de la croissance tumorale et une régression complète chez 20% des souris traitées. Par la suite, l'analyse des tumeurs TRAMP-C2 traitées in vivo avec le PCA3-TSTA-mIL-12 a montré l'induction de l'expression de mIL-12 mais aussi d'une réponse cytokinique impliquant l'IFN-γ. L'infection de biopsies de cancer de prostate humain par le PCA3-TSTA-mIL-12 a également induit une sécrétion d'IFN-γ dans certains échantillons, suggérant la stimulation, par l'IL-12 murine, de cellules T CD8+ ou NK infiltrant ces biopsies. Nos analyses en cytométrie de flux ont montré que les cellules immunes infiltrant les tumeurs TRAMP-C2 sont caractérisées par l'expression de PD-1 et plus faiblement de CTLA-4 et que cette infiltration est caractérisée par une importante proportion de MDSC. Nous avons donc analysé l'effet antitumoral du PCA3-TSTA-mIL-12 en combinaison avec des anticorps anti-PD-1 et anti-CTLA-4. La combinaison du PCA3-TSTA-mIL-12 avec un anticorps bloquant le CTLA-4 a montré une régression tumorale complète chez 33% des souris traitées contre 16% lorsque que le virus était combiné avec un anticorps inhibant le PD-1. Finalement, nous avons testé la combinaison d'un inhibiteur de PD-1 avec le tasquinimod, un composé inhibiteur de la fonction des MDSC. Nous n'avons cependant pas pu mettre en évidence d'effet significatif de cette combinaison sur la croissance des tumeurs TRAMP-C2. Globalement, nos résultats ont démontré que le vecteur adénoviral PCA3-TSTA permet d'induire l'expression localisée et durable de molécules immunomodulatrices par des cellules tumorales prostatiques. L'injection du PCA3-TSTA-mIL-12 dans des tumeurs TRAMP-C2 in vivo et des biopsies de cancer de prostate humain in vitro nous ont permis de mettre en évidence la production de cytokines par les cellules immunes infiltrant ces tumeurs en réponse à la production de mIL-12. Ces protocoles permettraient dans des travaux futurs de tester différents vecteurs PCA3-TSTA afin de sélectionner des combinaisons optimales de signaux immuns capables d'activer une réponse antitumorale pouvant mener à des effets immunothérapeutiques cliniques. / In men, prostate cancer is, worldwide, the 2nd most diagnosed cancer and the 5th most lethal cancer. When localized to the prostate, it is mainly treated with prostatectomy or radiation therapy. However, between 27 and 53% of patients treated at this stage will eventually develop a recurrence. Hormone therapy, which aims to reduce the effect of androgens on cancer, significantly increases the survival of these patients. On the other hand, these cancers will become irremediably resistant to castration and then evolve into the metastatic form for which there is no cure. Thus, new therapies are needed to increase the survival of these patients. A significant number of studies aimed at the development of immunotherapies for prostate cancer have emerged in recent years. These studies led, among other things, to the development of Sipuleucel-T, the first immunotherapy approved for the treatment of prostate cancer, as well as the study of the antitumor effect of immunological checkpoint inhibitors. These treatments, mainly tested on advanced cancers, have shown very limited effects and in some cases, significant adverse effects. Several studies highlight the importance of administering treatments earlier in the course of the disease and suggest that local administration of combinations of immunomodulatory molecules may be effective while limiting adverse effects. The main objective of my project was to develop a new immunotherapeutic approach based on the use of the adenoviral vector PCA3-TSTA allowing the targeted expression to the tumor of immunostimulatory molecules. Targeted expression to the tumor is achieved by the specificity of the promoter of the human PCA3 long non-coding RNA, which is to date the most specific biomarker of prostate cancer, as well as the amplification of transcriptional activity by the TSTA system. These immunotherapeutic approaches were tested in the immunocompetent mouse model of prostate cancer TRAMP-C2. As a first step, we showed in mice carrying TRAMP-C2 tumors, tumor specificity and transcriptional activity in vivo for at least 21 days of the PCA3-TSTA adenovirus encoding luciferase. We then built and tested PCA3-TSTA adenoviruses encoding the murine forms of mGM-CSF, mIL-17A or mIL-12. Only early treatment of TRAMP-C2 tumors with PCA3-TSTA-mIL-12 adenovirus resulted in complete tumor regression in 100% of the treated mice. At a more advanced stage, this treatment induced a significant slowdown in tumor growth and complete regression in 20% of the treated mice. Subsequently, the analysis of TRAMP-C2 tumors treated in vivo with PCA3-TSTA-mIL-12 showed the induction of mIL-12 expression but also of a cytokine response involving IFN-γ. Infection of human prostate cancer biopsies with PCA3-TSTA-mIL-12 also induced secretion of IFN-γ in some samples, suggesting stimulation by murine IL-12 of CD8+ or NK T cells infiltrating these biopsies. Our flow cytometry analyses have shown that immune cells infiltrating TRAMP-C2 tumors are characterized by the expression of PD-1 and weaker expression of CTLA-4 and that this infiltration is characterized by a large proportion of MDSC. We therefore analyzed the antitumor effect of PCA3-TSTA-mIL-12 in combination with anti-PD-1 and anti-CTLA-4 antibodies. The combination of PCA3-TSTA-mIL-12 with a CTLA-4-blocking antibody showed complete tumor regression in 33% of treated mice compared to 16% when the virus was combined with a PD-1-inhibiting antibody. Finally, we tested the combination of a PD-1 inhibitor with tasquinimod, a compound that inhibits MDSC function. However, we could not show a significant effect of this combination on the growth of TRAMP-C2 tumors. Overall, our results demonstrated that the adenoviral vector PCA3-TSTA induces the localized and sustained expression of immunomodulatory molecules by prostate tumor cells. Injection of PCA3-TSTA-mIL-12 into TRAMP-C2 tumors in vivo and human prostate cancer biopsies in vitro allowed us to demonstrate the production of cytokines by immune cells infiltrating these tumors in response to the production of mIL-12. These protocols would allow in future work to test different PCA3-TSTA vectors in order to select optimal combinations of immune signals capable of activating an antitumor response that can lead to clinical immunotherapeutic effects.

Chaque année, environ 23 300 Canadiens se font diagnostiquer un cancer de la prostate. Malheureusement, 10% d'entre eux en mourront, représentant la troisième cause de décès par cancer chez les hommes. La recherche sur ce sujet est alors bien importante pour améliorer la compréhension de ce cancer afin de développer de nouvelles approches thérapeutiques qui ciblent le métabolisme des cellules. La prostate est une glande du système reproducteur mâle ayant un métabolisme unique. Cet organe possède un cycle de Krebs tronqué, de manière à pouvoir produire et sécréter un métabolite important, le citrate. Toutefois, lors de la tumorigenèse, ce profil métabolique est complètement reprogrammé pour favoriser la croissance des cellules tumorales et le citrate n'est non plus sécrété, mais redirigé vers le cycle de Krebs afin de produire de l'énergie. Toutefois, comment ce programme métabolique fonctionne dans la prostate, ainsi que comment les cellules tumorales piratent le métabolisme du citrate, restent encore bien mal compris et cela a été le sujet de mes travaux. Pour ce faire, j'ai initialement travaillé à l'optimisation de modèles d'organoïde de prostate, qui sont les premiers modèles à reproduire, *ex vivo*, le programme sécrétoire de citrate de la prostate. Après validation de ces modèles, tant chez la souris que chez l'humain, par immunohistochimie, immunofluorescence et métabolomique, j'ai ensuite travaillé à optimiser les méthodes de transductions lentivirales des organoïdes en culture primaire. Grâce à une méthode de modification génétique par shRNA, plusieurs enzymes et transporteurs ont été ciblés afin de comprendre leur rôle et les voies métaboliques impliquées dans la production et la sécrétion du citrate. Nous avons en premier lieu validé la répression d'expression par qRT-PCR et par immunobuvardage de type Western, puis effectué des essais enzymatiques ainsi que des tests de prolifération cellulaire. Nous avons notamment identifié l'enzyme isocitrate déshydrogénase 1 (IDH1) comme étant essentielle pour le métabolisme des cellules tumorales. Mes travaux contribuent à mettre en évidence IDH1 comme nouvelle cible thérapeutique contre le cancer de la prostate. Globalement, les travaux présentés dans ce mémoire permettront une meilleure compréhension du métabolisme de la prostate saine et de sa reprogrammation durant la tumorigenèse. À terme, nous espérons que ces découvertes mèneront au développement de nouvelles approches thérapeutiques ciblant le métabolisme tumoral. / Every year, approximately 23,300 Canadians are diagnosed with prostate cancer. Sadly, 10% of them will dieof it, representing the third leading cause of cancer death in men. Research on this subject is therefore vital to improve our understanding of this cancer, and to develop new therapeutic approaches that target cell metabolism. The prostate is a gland of the male reproductive system with a unique metabolism. This organ has a truncated Krebs cycle, so that it can produce and secrete an important metabolite, citrate. However, during tumorigenesis, this metabolic profile is completely reprogrammed to promote tumor cell growth, and citrate is no longer secreted, but redirected to the Krebs cycle for energy production. However, how this metabolic program works in the prostate, and how tumor cells hack citrate metabolism, is still poorly understood and was the subject of my work. To do so, I initially worked on optimizing prostate organoid models, which are the first models to reproduce, *ex vivo*, the citrate secretory program of the prostate. After validating these models by immunohistochemistry, immunofluorescence and metabolomics, I then worked on optimizing lentiviral transduction methods for organoids in primary culture. Using a shRNA-mediated genetic modification method, several enzymes and transporters were targeted in order to understand their role and the metabolic pathways involved in citrate production and secretion. We first validated expression repression by qRT-PCR and Western immunoblotting, followed by enzymatic and cell proliferation assays. In particular, we identified the enzyme isocitrate dehydrogenase 1 (IDH1) as essential for tumor cell metabolism. My work is helping to identify IDH1 as a new therapeutic target for prostate cancer. Overall, the work presented in this thesis will lead to a better understanding of healthy prostate metabolism and its reprogramming during tumorigenesis. Ultimately, we hope these findings will lead to the development of new therapeutic approaches targeting tumor metabolism

Yes / The aim of this study was to assess the relationship between pre-prostatectomy urinary Engrailed-2 (EN2), a transcription factor secreted by prostate cancer cells, with tumour volume and pathological characteristics in resected prostate specimens. First pass urine samples (10 ml) without prior prostatic massage were collected and stored at –80°C. EN2 levels were measured using an enzyme-linked immunoabsorbent assay. Tumour volume in the prostatectomy specimens was determined histologically. 57 men undergoing RP in one urological cancer network were evaluated. EN2 was detected in 85% of RP patients. EN2 correlated with tumour volume (but not total prostatic volume) in a linear regression analysis, with increasing pathological T stage and margin positivity. Using three “cutoff levels” of tumour volume (0.5 ml, 1.3 ml and 2.5 ml) to define “significant disease”, men with “significant disease” had markedly higher levels of urinary EN2 (p < 0.001 for each cut off level). Levels of urinary EN2 may be useful in predicting tumour volume in men with prostate cancer by potentially identifying men with small volume “insignificant” disease. This study justifies a larger multicentre evaluation of urinary EN2 levels as a biomarker of PC significance using cancer volume, pathological and PSA criteria.

Thesis (MSc)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Prostate cancer (CaP) has the highest incidence of any malignancy affecting South African males. The aetiology of prostate carcinoma indicate that ethnicity is one of the most important risk factors. The causes of these ethnic differences are unknown but presumably involve both environmental and genetic factors. Carcinoma of the prostate is androgen dependent, and it has been suggested that variations in androgen metabolism and synthesis may affect an individuals' risk. Therefore, genes involved in these pathways are candidates for determining CaP susceptibility. In this study two candidate genes in the androgen biosynthetic and metabolic pathway were analysed, viz., the androgen receptor gene (AR), involved in androgen transport and transcriptional activation, and the cytochrome p450c17a gene (CYP17), important for testosterone biosynthesis. Comprehensive mutation detection assays were designed (appropriate for analysis of archival paraffin-embedded material) for almost the entire coding region (excluding polymorphic repeat sequences), and including all splice site junctions of the AR gene, as well as the entire coding region of CYP17. The aim of this study was thus to determine the type and frequencies of genetic variants of these androgen metabolism genes within the diverse South African population, and to determine if the observed ethnic variation in the incidence and progression of CaP can be explained by ethnic-based genetic differences. For high sensitivity mutation detection, the most powerful of the pre-screening methods was used, namely denaturing gradient gel electrophoresis (DGGE). 20 CaP and 25 control benign prostatic hyperplasia (BPH) tissue samples were screened in order to identify possible mutations. Blood samples from the same patients were analysed in order to determine whether mutations are germline and therefore present in all cells of the body. Additional blood samples from the Western Province Blood Transfusion Service (WPBTS) (Refer to section 2.1.2, Table) were also analysed in order to determine the frequency of identified polymorphisms within the general population. Certain polymorphisms were further analysed in paraffin-embedded wax material (exclusively from Blacks) to determine the distribution of these polymorphisms in the Black population. Direct sequencing of mutant-containing DNA fragments was performed to determine the exact location and nature of mutation. Using the AR- DGGE assay 4 novel mutations were identified as well as a previously reported codon 211 (E211) polymorphism. With the CYP17- DGGE assay, 3 novel single nucleotide polymorphisms (SNPs) were detected. Three base variants occured, in codons 36 (L36), 46 (H46) and 65 (S65), as well as intronic substitutions in intron 4 (IVS+58G4C) and intron 6 (IVS-25C7A). Frequencies of SNPs were measured in the CaP and BPH samples. In conclusion, the identified polymorphisms could be used as markers in determining CaP susceptibility and may thus facilitate the identification of individuals with a high- or low-risk of developing carcinoma of the prostate. / AFRIKAANSE OPSOMMING: Prostaatkanker vertoon die hoogste voorkoms van enige kwaardaardigheid wat Suid-Afrikaanse mans aantas. Die etiologie van prostaatkarsinoom dui aan dat etnisiteit een van die mees belangrike risikofaktore is. Oorsake van hierdie etniese verskille is onbekend, maar vermoedelik is omgewing en genetiese faktore albei betrokke. Karsinoom van die prostaat is androgeenafhanklik en daar is voorgestel dat variasies in androgeenmetabolisme en androgeensintese 'n persoon se risiko mag affekteer. Gevolglik, is gene betrokke in hierdie paaie kandidate vir die bepaling van prostaatkanker vatbaarheid. In hierdie studie het ons twee kandidaat gene in die androgeen biosintetiese en metaboliese pad geanaliseer, naamlik, die androgeen reseptor geen (AR), betrokke in androgeen vervoer en aktivering van transkripsie, en die sitokroom p450c17a geen (CYP17), belangrik vir testosteroon biosintese. Ons het omvattende mutasie-bespeurings-essai-sisteme ontwikkel (ook uitvoerbaar op argivale paraffien-bewaarde materiaal), wat amper vir die hele koderende streek van die AR geen gebruik kan word (uitsluitend herhalende polimorfiese reekse) en wat alle splytpunt-aansluitings van die AR geen insluit, asook vir die hele koderende streek van CYP17. Die doel van hierdie studie was dus om die tipe en frekwensies van genetiese variante van androgeen metabolisme gene in ons diverse Suid-Afrikaanse bevolking te bepaal, en om vas te stel of die waarneembare etniese wisseling in die insidensie en vordering van prostaatkanker verstaan kan word deur etnies gebaseerde genetiese verskille. Die mees sensitiewe tegniek wat tans beskikbaar is vir vooraf-sifting vir onbekende mutasies is gekies, naamlik denaturerende gradiënt gel elektroforese (DGGE). Om moontlike mutasies op te spoor, het ons 20 prostaatkanker en 25 benijne prostaathiperplasie (BPH) monsters geanaliseer. Analise was gedoen op bloedmonsters van dieselfde pasiënte om vas te stel of kiemlyn mutasies (in alle liggaamselle) teenwoordig is. Bykomstige bloedmonsters (van die Westelike Provinsie Bloedoortappingsdiens) is ook geanaliseer om die frekwensie van bespeurde polimorfismes in die algemene bevolking te bepaal. Argivale paraffien-bewaarde materiaal (eksklusief van Swartes) is ook geanaliseer om die verspreiding van sekere polimorfismes in die Swart bevolking te bepaal. Direkte DNA volgorde bepaling van mutante DNA fragmente is uitgevoer om die ligging en tipe van mutasies te bepaal. Met die toepassing van ons AR-DGGE mutasiesisteem het ons 4 nuwe mutasies ontdek asook 'n kodon 211 (E211) polimorfisme wat voorheen gevind is. Vyf enkel nukleotied polimorfismes is met die CYP17-DGGE mutasiesisteem opgespoor. Die polimorfismes sluit in: drie basis veranderinge wat voorkom in kodons 36 (L36), 46 (H46) en 65 (S65), asook introniese substitutisies in intron 4 (IVS+58G4C) en intron 6 (IVS-25C7 A). Frekwensies van die polimorfismes was bereken in die prostaatkanker en BPH monsters. Die resultate aangebied in hierdie tesis dui aan dat die gevonde polimorfismes as merkers gebruik kan word om prostaatkanker vatbaarheid te bepaal en daardeur individue te identifiseer met 'n hoë of lae risiko vir prostaatkarsinoom ontwikkeling.

Prostate cell lines were derived from two regions of prostate tissue from the same patient. The objective was to produce cell lines (as a useful in vitro model) from these two different regions which exhibit different properties for carcinoma development. The tissue was obtained from patients suffering from benign prostate hyperplasia undergoing trans-urethral resection. Tissue was taken from the deep (peripheral) and superficial (peri-urethral) areas. The cells were immortalised by transduction with constructs over expressing the cdk4 and hTERT genes. These cell lines were then characterised for their cellular phenotypes utilized for radiation transformation studies and utilized to investigate the role of plant derived polyphenols on normal and tumour cells. The cell line from the superficial region (P21s) was treated to fractionated doses of gamma radiation and a transformed cloned cell line was derived (P21s 40Gy (clone-a)). The cell line from the deep region (P21d) was found to consist of a mixed population of abnormal cells and a transformed cloned cell line was derived from it (P21d 0Gy (clone-a). In an attempt to obtain a normal P21d cell line cloned cell lines from early passage P21d cells were established. All seven cloned lines were abnormal with an average of 80 chromosomes per cell, invasive using a Matrigel assay and produced anchorage independent colonies. All cell lines were fully characterised with immunocytochemistry, chromosome analysis, invasion assays, and anchorage independent colony formation. P21s expressed basal cell markers (cytokeratin 5 (CK5) and 14), were positive for stem cell markers (prostate specific stem cell antigen PSCA, CK6), positive for p16, p63 and telomerase expression and negative for c-Myc expression. P21s was not invasive in a Matrigel assay and did not produce anchorage independent colony formation. P21d and P21d 0Gy (clone-a) also expressed CK5, CK14, PSCA, CK6, and telomerase but not p16 or p63 and showed an increase in expression of nuclear c-Myc, highly invasive and produced anchorage independent colonies. P21s 40Gy (clone-a) expressed CK5, CK14, PSCA, CK6, telomerase and p63, produced anchorage independent colonies, and was weakly positive for c-Myc expression. Spectral karyotyping analysis (SKY) showed P21s had a normal chromosome complement except an additional chromosome 20 whereas the P21s 40Gy (clone-a), P21d and P21d 0Gy (clone-a) cell lines had an abnormal chromosome complement with P21d and P21d 0Gy (clone-a) cell lines expressing multiple copies of every chromosome including loss of the Y chromosome. These results were echoed in the single nucleotide polymorphism chip (SNP) results which showed P21s as normal but P21d and P21d 0Gy (clone-a) to have large deletion and amplification regions that correlated with the SKY analysis. No differential cytotoxic response was noted between normal and abnormal cell lines including prostatic carcinoma cell lines LNCaP and PC-3 following treatment with strawberry polyphenol compounds. Most reports of a cytotoxic response to tumour cells in the literature did not compare the response to normal cells and used established cell lines. Human lymphocytes were also tested and all compounds were toxic in high doses. Polyphenol and ellagitannin rich polyphenol fractions were very cytotoxic and the anthocyanin rich fraction less toxic. In contrast to the lack of a direct differential cytotoxic effect, plant polyphenols did produce a protective effect to a carcinogenic insult. However a protective effect was noted via micronucleus assay with 3 hour incubation with the polyphenol rich fraction prior to radiation treatment. Finally, the expression and association of metabolic enzymes within the cells cytosol were investigated. The P21s cells were found to express both isoforms of LDH and so thought to be able to metabolise anaerobically and aerobically. P21d and P21d 0Gy (clone-a) cells were found to only express one isoform in the complex and so it was assumed that these cells favoured anaerobic metabolism of ATP in correlation to the Warburg effect. c-Myc association with compounds in the cell cytosol of P21s cells existed whereas, abnormal cells lost this association along with up-regulation of c-Myc expression and down stream targets of c-Myc in the nuclei. Thus these newly established human prostate cell lines provide a useful model system for investigating the biology of the prostate and prostate cancer.

Cancer of the prostate (CaP) is the most common malignancy diagnosed in men in the Western society. During the last years, prostate specific antigen (PSA) has been used as a biomarker for CaP, although a high PSA value is not specific for CaP. Thus, there is an urgent need for new and improved diagnostic markers for CaP. In this thesis, the aim was to find a miRNA signature for diagnosis of CaP and to elucidate if differences in behavior between transition zone and peripheral zone tumors are reflected in miRNA expression. One of the major findings is anexpression signature based on nine miRNAs that with high accuracy (85%) could classify normal and malignant tissues from the transition zone of the prostate. The results furthermore show that the major differences in miRNA expression are found between normal and malignant tissues, rather than between the different zones. In addition, tumors arising in the peripheral zone have fewer changes in miRNA expression compared to tumors in the transition zone, indicating that the peripheral zone is more prone to tumor development compared to the transition zone of the prostate. A crucial step in pre-processing of expression data, in order to differentiate true biological changes, is the normalization step. Therefore, an additional aim of this thesis was to compare different normalization methods for qPCR array data in miRNA expression experiments. The results show that data-driven methods based on quantile normalization performs the best. The results also show that in smaller miRNA expression studies, only investigating a few miRNAs, RNU24 is the most suitable endogenous control gene for normalization. Taken together, the results in this thesis show the importance of miRNAs and the possibility of their future use as biomarkers in the field of prostate cancer.

Les pathologies du vieillissement prostatique (cancer de la prostate, hyperplasie bénigne de la prostate, déficit androgénique lié à l'âge) sont fréquentes, représentant un problème de santé publique. Leur prévalence s'accroit au gré du vieillissement de la population. Si leur coïncidence épidémiologique est claire, les liens physiopathologiques les unissant restent mal connus. Grâce aux progrès de la génétique, et notamment les associations d'étude du génome entier, la quantification du risque génétique du cancer de la prostate sporadique a été documentée par la découverte de loci de susceptibilité. Néanmoins, l'utilisation de ces marqueurs en pratique courante n'a pas fait la preuve de sa rentabilité, dans le complexe débat du dépistage du cancer de la prostate. La prédisposition génétique au vieillissement pathologique bénin de la prostate, en particulier vers l'HBP, est encore très peu étudiée. De plus amples travaux sont nécessaires pour caractériser la genèse et l'évolution du vieillissement prostatique. Du point de vue du traitement, la prise en charge diagnostique du vieillissement prostatique évolue avec de nouveaux biomarqueurs. Le poids respectif de ces outils diagnostiques multiples reste à déterminer avec un triple objectif : (i) mettre en place des arbres de décision permettent de cibler les biopsies prostatiques, (ii) intégrer à la prise en charge diagnostique les pathologies bénignes comme l'HBP dont le bilan, le traitement et le suivi sont connexes à la problématique du CaP et (iii) considérer tout au long de la prise en charge les pathologies associées tel le syndrome métabolique, dans l'objectif d'une démarche multidisciplinaire. / Prostatic diseases due to ageing of the prostate gland (prostate cancer, benign prostatic hyperplasia, late onset hypogonadism) are frequent, and represent a major public health issue. Their prevalence gets higher along the ageing of the population in western countries. If an epidemiological link can be stated between these three diseases, the underlying pathophysiology remains unclear. With recent innovation in human genetics, notably genome wide association studies, the risk of non hereditary prostate cancer has been documented by the identification of susceptibility loci. However, the utility of these genetic markers in a clinical practice environment has not been yet established regarding the complex issue of prostate cancer screening. Genetic predisposition to benign prostate ageing, particularly BPH, has not been extensively studied. Additional investigations are necessary to adequately document the initial phase and evolution of the ageing prostate. From the therapeutic point of view, new biomarkers are about to modify the diagnosis of prostatic ageing. The respective role of each of these new diagnostic tools should be determined with a triple goal. First, improve decision making leading to prostatic biopsies. Then, proceed to integrative therapy of prostatic diseases (prostate cancer but also benign prostatic hyperplasia), and finally consider associated conditions, such as metabolic syndrome, to improve the level of care of the ageing male via a multidisciplinary approach.

"Prostate cancer (Pca) is the number one cancer in U.S. men and a leading cause of cancer-related deaths. The disease is initially dependent upon active male androgens for survival, such as testosterone or dihydrotestosterone. However, relatively inactive androgens like 5-androstenediol (5Adiol) have been considered to play larger roles in disease progression than previously considered. 5Adiol is synthesized in the prostate, is not affected by current anti-androgen therapies, and activates the androgen receptor in human prostate cancer cell lines more effectively than active male androgens. The causal relationship between androgens and prostate cancer progression has significantly risen due to anabolic steroid abuse in competitive sports and recreational athletes. The evidence surrounding an association between androgen abuse and prostate cancer, as well as various other carcinomas, is of great concern within this demographic because of its preventability. Despite their prohibited use, anabolic products continue to be marketed and available for purchase as nutritional supplements. Surveys on current steroid user trends have documented high dosing regimens, extended periods of use, multiple self-diagnosed side effects, and unsafe injection practices. Because few studies have investigated the effects of advertised 5Adiol products on prostate cancer progression, the goal of this study was to investigate whether Value Nutrition’s 5Adiol product possesses comparable mitogenic stimulant activity to testosterone in the androgen-dependent cell line, LNCaP. It should be noted that while this compound is banned by the U.S. Drug Enforcement Administration and is no longer sold through this company, alternative steroids continue to be marketed to consumers. Additional goals included determining whether this product would affect the proliferation of liver cells using the HepG2 cell line, if HepG2 metabolism of the product would play a role in the proliferation of LNCaP cells, and whether the LNCaP cells are capable of converting the 5Adiol product into testosterone. Multiple assays determined that the LNCaP cells were androgen responsive to the 5Adiol product, HepG2 proliferation was stimulated, and HepG2 metabolism of the 5Adiol product increased LNCaP mitogenicity, although significant differences were unattainable primarily due to the LNCaP cells reduced adhesion properties. Because reverse-phase HPLC was unable to detect compounds within 5Adiol even at high concentrations, the mitogenicity observed in both cell lines is unable to be correlated with a particular component in this product. While it is possible that 5Adiol is present at extremely low levels, contamination with other factors, hazardous or not, cannot be ruled out. In conclusion, these results suggest that the use of nutraceuticals have inherent risks for men at risk of developing prostate cancer. The mitogenic effects observed from small levels of unknown compounds in the tested 5Adiol product raise serious questions as to the legitimacy of allowing companies to market and self-regulate their own products."

No description available.

Le récepteur du mannose 6-phosphate cation indépendant (RM6P-CI) permet l'endocytose puis le transfert de molécules porteuses du marqueur mannose 6-phosphate (M6P) vers les lysosomes. Le RM6P-CI, qui est surexprimé par les cellules de cancer de la prostate, est une cible de choix pour augmenter la délivrance de principes actifs dans ces cellules. Cependant le M6P est dégradé par les phosphatases présentes dans le sérum. Dans le but d'augmenter à la fois la stabilité et l'affinité pour le RM6P-CI, nous avons entrepris la synthèse d'analogues isostères du mannose 6-phosphate. Ces analogues sont fonctionnalisés en position anomère afin de permettre leur greffage sur des nanoparticules de silice mésoporeuse incorporant un photosensibilisateur. L'évaluation biologique a montré un gain d'affinité des nouveaux analogues synthétisés pour le RM6P-CI ainsi qu'une forte augmentation de l'efficacité des nanoparticules fonctionnalisées avec les analogues pour la thérapie photodynamique, in vitro, de cellules de cancer de la prostate. / The cation independant mannose 6-phosphate receptor (CI-M6PR) allows the endocytosis and the transport of mannose 6-phosphate (M6P) bearing molecules toward the lysosomes. The CI-M6PR, which is overexpressed by prostate cancer cells, is a target of interest to increase drug delivery in these cells. However, M6P is sensitive to degradation by phosphatases in the serum. To increase both the stability and the affinity for the CI-M6PR, we synthesized new M6P isosteric analogs. These analogs are functionnalized at the anomeric position to permit their grafting on mesoporous silica nanoparticles incorporating a photosensitizer. The biological evaluation demonstrated an affinity gain of the new analogs for the CI-M6PR as well as an increase of the efficacy of the nanoparticles functionnalized with these analogs for the in vitro photodynamic therapy of cancer prostate cells.