No description available.

Accounting for 14% of all new cancer diagnosis in the United States, prostate cancer is the most commonly diagnosed cancer and the second leading cause of cancer related death in the United States. Prognosis for patients diagnosed with metastatic disease is especially poor, since no effective treatments have been developed (1). In this study, we examined the expression and function of POU5F1B, a protein-encoding pseudogene of the homeodomain transcription factor Oct4, in prostate cancer. POU5F1B is located at 8q24, a "gene desert" containing numerous alleles associated with prostate cancer risk. A recent study has indicated that a number of these risk alleles are correlated with POU5F1B expression and prostate cancer susceptibility. The role of POU5F1B in prostate cancer carcinogenesis and progression, however, is not known. In our study, we found that POU5F1B expression is upregulated in prostate cancers and highly overexpressed by high grade (Gleason ≥8) and metastatic prostate cancers. We cloned POU5F1B from prostate cancer cell lines, which contains prostate cancer risk associated SNPs, including a missense mutation inside the homeobox DNA binding domain, to study the functional effects of POU5F1B overexpression in prostate cancers. Here, we report that POU5F1B from prostate tumor encodes functional proteins that exhibit gene transactivation activity comparable to its parent gene, Oct4. Further, we report that POU5F1B overexpression in prostate cancer cell lines increases prostate cancer cell proliferation, migration, anchorage independent growth, and drug resistance in vitro and tumor xenograft growth in vivo. Conversely, shRNA mediated knockdown of endogenous POU5F1B expression in prostate cancer cells inhibit cell proliferation in vitro and tumor growth in vivo, as well as prolong tumor free survival in animal models. The data provide compelling evidence that POU5F1B is an important mediator of prostate cancer progression. We further examined the molecular mechanism behind POU5F1B driven prostate cancer progression. Our studies found that POU5F1B overexpression suppresses E-Cadherin expression at both mRNA and protein levels. Our studies further found POU5F1B overexpression in prostate cancer cells increases Wnt1, TCF1, and TCF4 expression, as well as increased Wnt/β-Catenin signaling - indicating the induction of epithelial-to-mesenchymal transition (EMT) in POU5F1B overexpressing cells(2). Consistently, qPCR analysis found that POU5F1B overexpression significantly increased the expressions of numerous EMT related genes and prostate cancer stem cell markers. Functional studies further confirmed that the transactivation activity of Nanog, another stem cell related transcription factor, is dramatically increased in POU5F1B overexpressing cells. Taken together, our data strongly suggests that POU5F1B overexpression drives prostate cancer progression through the induction of EMT and conferment of stem-cell properties to tumor cells. In summary, our data demonstrated that POU5F1B is overexpressed in prostate tumors, especially high-grade and metastatic tumors, and is a functional driver of prostate cancer progression by inducing EMT in prostate cancer cells. Our study also showed that POU5F1B can potentially be targeted to treat prostate cancer. Based on our findings, depletion of POU5F1B may reduce the risk of metastatic disease or tumor recurrence when used with concurrent therapies in early state tumors and may attenuate treatment resistance in diseases at advanced stages.

No description available.

Le cancer de la prostate est le premier cancer en incidence et le troisième au niveau de la mortalité chez les hommes canadiens. Selon les estimations de la société canadienne du cancer pour l'année 2020, près de 23 300 hommes recevront un diagnostic et 4 200 mourront de la maladie. Le cancer de la prostate est l'un des rares cancers à évolution lente. Toutefois, il présente beaucoup de variabilité dans les risques de récidive, de réponse aux traitements et de décès spécifique chez des patients ayant des caractéristiques clinico-pathologiques similaires. Il y a donc un grand besoin pour le développement d'outils prédictifs plus précis pour l'évolution et la classification de la maladie. Dans les dernières années il y a de plus en plus d'indices qui suggèrent qu'une analyse exhaustive des cellules immunitaires infiltrant les tumeurs pourrait aider à prédire l'évolution des cancers. Nous avons donc émis l'hypothèse que l'étude de l'infiltration de cellules immunes dans le microenvironnement du cancer de la prostate chez des patients traités par prostatectomie radicale pourrait prédire l'évolution de la maladie. Nous avons utilisé deux techniques pour analyser l'environnement immunitaire dans le cancer de la prostate. Tout d'abord, nous avons établi le profil d'infiltration immunitaire du microenvironnement prostatique cancéreux par des marquages immunohistochimiques, en nous intéressant non seulement au type, mais aussi à la quantité et à la localisation des cellules immunes dans les différents compartiments du microenvironnement tumoral. Nos expériences ont montré tout d'abord, que l'infiltration dans la zone centrale de la tumeur par des cellules présentatrices d'antigènes ne permet pas de prédire l'évolution du PCa. Toutefois, l'infiltration dans l'épithélium péritumoral normal et dans la marge tumorale par ces cellules est associée avec l'évolution de la maladie. Soit, en augmentant les risques de progresser vers une récidive biochimique, pour des fortes infiltrations de cellules dendritiques immatures CD209+ dans la marge tumorale et un PCa létal pour une forte infiltration de macrophages M2 CD163+ dans l'épithélium péritumoral normal. Ou bien en diminuant les risques de traitements d'hormonothérapie définitive ou de PCa létal, pour une forte infiltration de cellules dendritiques matures CD83+ dans l'épithélium péritumoral normal et la marge tumorale. Par la suite, nos analyses ont montré que la valeur prédictive de l'infiltration des lymphocytes se concentre principalement dans la zone centrale de la tumeur, tel que démontré par les risques accrus de récidive biochimique par des ratios intra tumoraux faibles de CD45RO/CD3 et hauts des FoxP3/CD45RO. Nous avons observé aussi des risques plus faibles de traitements d'hormonothérapie définitive pour des faibles ratios dans la tumeur de FoxP3/CD3 et FoxP3/CD45RO ainsi que, des risques diminués de PCa létal pour un haut ratio de CD45RO/CD3 dans l'épithélium tumoral. En complément, nous avons effectué une analyse du profil d'expression génique en ciblant une série de gènes liés à la fonction immunitaire à l'aide d'expériences de RT-qPCR dans le but de bonifier les expériences d'immunohistochimie. Ces expériences nous ont permis d'identifier un sous-groupe des gènes liés à la fonction des cellules présentatrices d'antigènes pour lequel une surexpression est associée à des taux de survie sans PCa léthal diminués. De plus, nous avons mis en évidence la protéine TIM-3 comme étant un point contrôle immunologique important dans la progression du PCa, puisque des taux élevés d'expression de ce PCI sont associées à des survies plus courtes sans besoin de traitements d'hormonothérapie définitive. Les résultats de nos travaux ont permis de mettre en évidence l'importance de tenir compte des compartiments de la tumeur dans une étude exhaustive de l'infiltration immune dans le PCa. En effet, nos données suggèrent que la valeur pronostique de l'infiltration immune dépend du type et de la densité des cellules infiltrés mais aussi de leur localisation dans le microenvironnement tumoral. De plus, nous avons pu identifier des acteurs importants dans l'évolution de la maladie, tels que les cellules exprimant FoxP3, CD45RO, CD163, CD209 ainsi que le point de contrôle immunologique TIM-3. La méthodologie de cette étude pourrait être adaptée à la réalité clinique en analysant les biopsies préopératoires. L'utilisation d'un tel outil pronostic en combinaison avec les tests clinico-pathologiques de routine pourrait aider à identifier les patients qui pourraient bénéficier d'immunothérapies intra-prostatiques avant la chirurgie destinée à renverser cet état immunosuppresseur dans un contexte de médecine de précision. / Prostate cancer is the most common cancer and the third leading cause of death from cancer among Canadian men. According to Cancer Canada, in 2020 23 300 men will be diagnosed and 4 200 men will die from prostate cancer. Prostate cancer is one of the rarest cancers to have a slow evolution. However, there is a considerable variation in disease recurrence, treatment response and disease-specific death between individuals showing similar clinico-pathological characteristics. There is therefore a great need for the development of more precise predictive tools for the evolution and the classification of the disease. In recent years, there is a growing evidence suggesting that a comprehensive analysis of tumor-infiltrating immune cells could help to predict cancer progression. We therefore hypothesized that the study of immune cell infiltration in the prostate cancer microenvironment in patients treated by radical prostatectomy can predict the evolution of the disease. We used two techniques to analyze the immune context in prostate cancer. First, we profiled the immune microenvironment of the prostate cancer by immunohistochemistry. By focusing not only on the type, but also the quantity and the localization of immune-infiltrating cells in the various compartments of the tumor microenvironment. Our experiments showed that antigen-presenting cells infiltrating the center of the tumor does not predict the evolution of prostate cancer. On the other hand, infiltration into the normal-like peritumoral epithelium and the tumor margin are associated with the evolutions of the disease either by increasing the risks of progressing to biochemical recurrence for high infiltration by immature CD209+ dendritic cells in the tumor margin and higher risks of lethal PCa for high infiltration by CD163+ M2 macrophages in the tumor margin and normal-like peritumoral epithelium. Or by reducing the risks of definitive androgen deprivation therapy (ADT) or lethal PCa for a high infiltration by mature CD83+ dendritic cells in the normal-like peritumoral epithelium and the tumor margin. Subsequently, our analyzes showed that the predictive value of lymphocyte infiltration is mainly concentrated in the tumor center, as demonstrated by the increased risks of biochemical recurrence by intra-tumor low ratios of CD45RO/CD3 and high ratio of FoxP3/CD45RO. In addition, a lower risk of definitive ADT for low tumor ratios of FoxP3/CD3 and FoxP3/CD45RO and a decreased risk of lethal PCa for a high CD45RO/CD3 ratio in the tumor epithelium was also observed. Secondly, we performed gene expression profile analysis targeting a series of genes related to immune function using RT-qPCR experiments to complement the immunohistochemistry experiments. These experiments allowed us to identify a subgroup of genes related to the function of antigen presenting cells in which, overexpression is associated with decreased rates of lethal prostate cancer-free survival. In addition, we identified TIM-3 as being an important immunecheckpoint in the progression of prostate cancer since high expression levels of TIM-3 are associated with shorter survival to definitive ADT. The findings of our work have highlighted the importance of tumor compartments in a comprehensive study of immune infiltration in prostate cancer. Indeed, our data suggest that the prognostic value of immune infiltration depends on the type and density of the infiltrated cells but also on their location in the tumor microenvironment. In addition, we were able to identify important players in the evolution of the disease, such as cells expressing FoxP3, CD45RO, CD163, CD209 and the immune checkpoint TIM-3. The methodology of this study could be adapted to clinical reality with the analysis of preoperative biopsies. The use of such a prognostic tool in combination with routine clinico-pathologic tests could help identify patients who might benefit from intra prostatic immunotherapies prior to surgery to reverse this immunosuppressive condition in a context of precision medicine.

No description available.

No description available.

Affecting one in every eight Canadian men, prostate cancer is the most common type of cancer among males. As with other forms of cancer, men with prostate cancer are much more likely to develop comorbid depression than the general population without cancer diagnoses. Depression negatively affects these men’s quality of life and increases mortality rates among cancer patients. Therefore, effective therapies to manage depression in this unique subpopulation are needed. This project sets out to assess the efficacy of glutamate-targeting drugs as antidepressants. The major excitatory neurotransmitter in the central nervous system, glutamate is released in excessive quantities by cancer cells. It is thought that this abundance of glutamate leads to excitotoxicity and neurodegeneration, affecting neurons in important regions of the brain relating to mood and mood regulation. A validated mouse model of depression was established using RM1 murine prostate cancer cells. This model was then used to test the properties of three drugs: sulfasalazine (SSZ), (S)-4-carboxyphenylglycine ((S)-4-CPG), and 2,3-dioxo-6-nitro-1,2,3,4-tetrahydro-benzo[f]quinoxaline-7-sulfonamide (NBQX). Results show that these drugs were able to improve depressive-like behaviours and symptoms to varying degrees, at least partially reversing the negative effects of tumours. This project showed that disrupting glutamate release and/or signaling could be an effective approach for an antidepressant therapy or adjuvant in prostate cancer patients. / Thesis / Master of Science (MSc) / Prostate cancer affects one in every eight Canadian men. Cancer patients are at a much higher risk of developing depression than the rest of the population. Unfortunately, current antidepressants are limited in their ability to improve depressive symptoms in cancer patients. Therefore, this project sets out to identify new options for treating depression in prostate cancer patients. Glutamate is a signalling molecule that is released in abundance by cancer cells and is largely responsible for communication between neurons in the central nervous system. This project showed that limiting the amount of glutamate released by cancer cells and limiting glutamate-based signaling improves depressive-like symptoms in mice with prostate cancer tumours. These results suggest that targeting glutamate could be an effective antidepressant therapy in the cancer population.

Patients with prostate cancer (PC) are at high risk of developing migratory thrombosis compared to healthy individuals. This is due to the haemostatic abnormality as a result of the presence of cancer, and is referred to as Trousseau’s syndrome. Trousseau's syndrome leads to increased mortality among cancer patients, and is considered the second cause of death after cancer itself. We investigated the role of microvesicles (MVs), which are circular membrane compartments shed from cancer as well as from healthy cells, in the development of Trousseau’s syndrome. We compared the pro-coagulant activities between MVs derived from PC cell lines with different oncogenic and metastatic characteristics, using chromogenic assays to determine their thrombin generation. Microvesicles from the more aggressive DU145vIII and more metastatic PC3-MLN4 show increased thrombin generation compared to MVs derived from DU145 and PC3. We also compared thrombin generation in MVs extracted from plasma of PC patients of various cancer stages. MVs from PC patients with a metastasized tumour had increased thrombin generation compared to patients with localized tumours. Finally, we transfected the CHO cell line with the human protease-activated receptor 1 (hPAR1), the principal receptor of thrombin. PC MVs led to the activation of PAR1 in CHO (hPAR1), indicating thrombin generation. Our in vitro studies suggest a potential role of PC MVs in the migratory thrombosis observed in Trousseau’s syndrome, due to their independent ability to generate active thrombin. We also demonstrated that thrombin generation of PC-derived MVs correlated with the oncogenic and metastatic characteristics of prostate cancer. / Thesis / Master of Science (MSc)

Aim: Several studies have tried to quantify overdiagnosis of prostate cancer with Prostate-specific antigen(PSA) screening, but estimates vary widely. This study aims to evaluate the degree of overdiagnosis of prostate cancer with 10 or 14 follow-up years after the stop of screening in Finland. Methods: We selected 80379 men aged 55-69 years who were randomized to a screening or a control arm, distinguishing four birth cohorts: 1941-44,1937-40, 1933-36 and 1929-32. The first PSA screening test occurred during1996-1999. Men without detected as prostate cancer in the previous screening would be invited to the next screening 4 years later. The estimate of overdiagnosis is the ratio of the cumulative excess incidence to the cumulative incidence of prostate cancer in the screened group after the year-specific incidence became stable. Results: The patterns of all incidences in these four cohorts have not become stable yet, and the difference of cumulative incidence in the current longest follow- up years is the best estimate of overdiagnosis so far. Conclusion: Overdiagnosis rates of prostate cancer in people who received screening in Finland was estimated as 2.27%,15.4%, 11.4%, and 10.2% for 1929-32, 1933-36,1937-40, and 1941-44 cohorts, respectively. / Thesis / Master of Science (MSc)

Une dérégulation du métabolisme des androgènes peut induire de graves pathologies comme le CaP (CaP). Pour le traiter, on utilise la thérapie de déprivation en androgène (ADTh). Néanmoins, le CaP s’adaptant, les traitements deviennent inefficaces. Trouver de nouvelles cibles thérapeutiques est donc essentiel. Nous sommes intéressés par la glucuronidation via les enzymes UGT2B15 et UGT2B17, la voie majeure d’inactivation des androgènes. Ce projet de recherche avait deux objectifs. 1) déterminer comment l’expression des UGT2B15 et UGT2B17 est régulée in vivo et in vitro avec ou sans ADTh, 2) créer une souris transgénique confirmant in vivo le rôle d’UGT2B15 dans la biodisponibilité des androgènes. Nous avons donc étudié la glucuronidation des androgènes par les Ugt2bs de souris, avant d’y insérer le gène UGT2B15 avec son promoteur endogène. Nous montrons qu’UGT2B15, et non UGT2B17, est inhibée dans les CaP les plus avancés tandis que l’ADTh induit les 2 UGT2Bs. In vitro, cette induction contribue à l’efficacité de l’ADTh, mais in vivo seule l’augmentation d’UGT2B15 est durable alors que celle d’UGT2B17 est transitoire. Nous constatons que la glucuronidation murine des androgènes est due aux Ugt2bs hépatiques et rénales, moins importante chez les femelles et régulée par les androgènes. La souris est donc un bon modèle pour induire une UGT2B humaine dans la prostate murine. Notre souris transgénique montre une expression d’UGT2B15 exclusivement dans le foie mâle et contrôlée par les androgènes. UGT2B15 augmente la LH plasmatique tandis que dans les souris transgéniques castrées et traitées à la DHT, le poids global et celui des muscles sont altérés. En conclusion, UGT2B15 est une cible thérapeutique pour traiter le CaP. Avec UGT2B17, elle participerait déjà à l’efficacité de l’ADTh, bien que les 2 enzymes aient une régulation différentielle. Ainsi, l’induction transitoire d’UGT2B17 serait un biomarqueur pour la résistance à l’ADTh. L’importance d’UGT2B15 est démontrée avec nos souris transgéniques où une expression hépatique a un effet systémique sur le système endocrinien. Notre modèle constitue un modèle pour étudier in vivo les régulations d’UGT2B15 et son impact sur les androgènes et pourrait servir à tester des inducteurs de cet enzyme afin d'améliorer l’ADTh. / Disregulation of androgen metabolism leads to serious diseases such as prostate cancer (PCa). Androgen déprivation (ADTh) is a common approach to treat PCa. Although most patients initialy respond to the treatment, up to 80% will develop resistant tumors (CRPC). New therapeutic approaches are therefore urgently needed. Our work focused is glucuronidation by the human UGT2B15 and UGT2B17 enzymes, a major inactivation pathway for androgens. Two parallel strategies were devepopped. First, we analyzed how UGT2B15 and UGT2B17 expression regulated in vitro and in vivo, in PCa from patient treated or not with ADTh. Second, we have engineered mouse strain expressing the UGT2B15 human gene. These animals were used to study the role of UGT2B15 in vivo, in particularly how this enzyme affects androgen biodisponibility. Before establishing the transgenic models, we investigated the Ugt2b enzyme implicated in androgen glucuronidation in mice. We observed that UGT2B15, and not UGT2B17, is down-regulated in advanced and metastatic PCa and CRPC, while using ADTh up-regulated the 2 proteins in vivo. In vitro, this increase contributed to the anti-proliferative effect of ADTh but in vivo, UGT2B15 is stably induced while UGT2B17 was only transiently up-regulated. In mice, androgen glucuronidation is mainly observed with hepatic and renal tissues, while Ugt2b peripheral expression is almost undetectable. Moreover this Ugt2b expression is lower in female and controlled by androgen. In our transgenic mouse, human UGT2B15 is also expressed in male liver only, and likewise controlled by androgen. Its expression significantly increases LH plasma concentration, while castrated transgenic mice treated with DHT display altered body and muscle weight. In conclusion we demonstrated that UGT2B15 is a pharmacological target for PCa treatment. With UGT2B17, UGT2B15 contributes to improve ADTh but the 2 enzymes have a differential expression. So, UGT2B17 is a potential biomarker for the emergence of ADTh resistance. The important UGT2B15 function is demonstrated using our transgenic mice: a liver limited expression is enough to alter the endocrine regulation with a hepatic limited expression. Also, our mouse constitutes a model to study in vivo the UGT2B15 regulation and function, in example to identify a UGT2B15 inductor to improve ADTh.