Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Prostate cancer constitutes the most common malignancy and the most common cause of cancer‐related death in Swedish men. A large body of evidence suggests that inherited genetic variants contribute to both development and progression of prostate cancer. The aim of this thesis is to identify genetic variants that alter prostate cancer risk and progression. All papers included in this thesis are based on a Swedish population‐based case‐control study (CAPS) comprising 2,965 incident prostate cancer cases and 1,823 controls. In paper I, we investigated if genetic variants in the E‐cadherin gene altered prostate cancer risk. Seven haplotype tagging SNPs(tagSNPs) were selected and genotyped in CAPS and families with hereditary prostate cancer. We confirmed association of a promoter SNP rs16260 previously reported to increase risk of hereditary prostate cancer (OR: 2.6; 95% CI: 1.6‐4.3) for homozygous ‘A’ carriers. In paper II, we assessed 46 polymorphisms earlier reported to be associated with prostate cancer risk. Six polymorphisms in five different genes were replicated. Interestingly, three of these genes were involved in the androgen biosynthesis. In paper III, we followed up on the results from paper II by genotyping 23 tagSNPs located in the hormone regulating genes AR, CYP17 and SRD5A2. Multiple SNPs and haplotypes were associated with prostate cancer risk, especially in the AR gene. Combining risk alleles from all genes revealed a substantial risk increase for each additional allele carried (OR: 1.12; 95% CI: 1.1‐1.2, P=0.00009). In paper IV, we collected information about cause of death for all case patients in CAPS. At time of follow‐up 300 study subjects were deceased from prostate cancer. We assessed AR, CYP17 and SRD5A2 variants for association with lethal prostate cancer and found overall no association. However, one AR promoter SNP was associated with an increased risk of dying from prostate cancer amongst men who received palliative hormonal therapy as primary treatment. In paper V, we assessed common genetic variation at the ERG locus for association between prostate cancer risk and survival. ERG is recognized as a protooncogene frequently overexpressed in prostate cancer. A total of 21 tagSNPs in the 5’ region of ERG were genotyped. There was no correlation between ERG SNPs and prostate cancer risk but common genetic variation located approximately 100,000 basepairs upstream of ERG was significantly associated with prostate cancer specific survival. In summary, our results suggest that common genetic variation in Ecadherin alters prostate cancer risk in Swedish men with a positive family history of prostate cancer. Moreover, common genetic variation in the androgen‐related genes AR, CYP17 and SRD5A2 affects the risk of developing prostate cancer but is unlikely to alter prostate cancer progression. However, genetic variants in AR may affect hormonal therapy response. Finally, ERG polymorphisms are associated with prostate cancer‐specific death but are not likely to play a role in prostate cancer development.

In Sweden, close to 10 000 men are annually diagnosed with prostate cancer (PCa) and approximately 2400 men die of their disease each year. Today there is no reliable marker that can separate patients who will have an aggressive type of disease that requires treatment, from patients who will have a more indolent clinical course and can be left untreated. This further leads to the current problem of over treatment of men with PCa. Hence, there is an urgent need for reliable prognostic markers that can be used at time of diagnosis. With the discovery of recurrent gene rearrangements in PCa, most commonly ERG rearrangements, hope came that this aberration could play a role in diagnosis and/or prognosis of the disease. The aim of this thesis was to investigate the clinical implication of ERG rearrangements in the management of PCa. The work in this thesis supports the findings from previous studies, suggesting that the ERG rearrangement is a sign of a more aggressive type of cancer. The major findings are that in multifocal PCa, the ERG rearranged cancer foci are more prone to metastatic dissemination compared to foci without the ERG rearrangement and that patients harboring the ERG rearrangement have a faster disease progression leading up to earlier start of hormonal treatment. Furthermore, the results add an additional level of complexity in a subset of PCa tumors that harbor multiple gene rearrangements on the cellular level. The result also show that the newly available ERG antibody is highly predictive of ERG rearrangement and is appropriate to use when faced with limitations in tissue amounts. The findings in this thesis indicate that the ERG rearrangement has a potential role in the clinical management of PCa but further studies arerequired.

Shortcomings of current methods of prostate cancer detection draw attention to a need for improved biomarkers. The TMPRSS2:ERG gene fusion leads to the overexpression of ERG, an ETS family transcription factor, and is the most prevalent genetic lesion in prostate cancer, but its clinical utility remains to be defined. Two radical prostatectomy samples were analysed by next-generation whole transcriptome sequencing. The chosen samples differed in fusion gene status, as previously determined by RT-PCR. The involvement of novel and previously reported prostate cancer-related transcripts, Wnt signalling, p53 effector loss and several ETS-regulated pathways was identified in the prostate cancer cases examined. ERG was found to directly transactivate RhoGDIB, a gene associated with fusion-positive prostate cancer. Overexpression of RhoGDIB elicited spindle-shaped morphology, faster cell migration and increased cell proliferation, phenotypic changes suggestive of cancer progression. The present findings confirm the value of comprehensive sequencing for biomarker development and indicate avenues of future study.

Shortcomings of current methods of prostate cancer detection draw attention to a need for improved biomarkers. The TMPRSS2:ERG gene fusion leads to the overexpression of ERG, an ETS family transcription factor, and is the most prevalent genetic lesion in prostate cancer, but its clinical utility remains to be defined. Two radical prostatectomy samples were analysed by next-generation whole transcriptome sequencing. The chosen samples differed in fusion gene status, as previously determined by RT-PCR. The involvement of novel and previously reported prostate cancer-related transcripts, Wnt signalling, p53 effector loss and several ETS-regulated pathways was identified in the prostate cancer cases examined. ERG was found to directly transactivate RhoGDIB, a gene associated with fusion-positive prostate cancer. Overexpression of RhoGDIB elicited spindle-shaped morphology, faster cell migration and increased cell proliferation, phenotypic changes suggestive of cancer progression. The present findings confirm the value of comprehensive sequencing for biomarker development and indicate avenues of future study.

Tidigare undersökningar av motivationen att utöva friluftsliv har identifierat motiv som social samvaro, fysisk aktivitet, naturupplevelser och avkoppling, dock har området mest berörts i samband med planering och förvaltning av naturområden. Den här studien har undersökt motiv bakom människans friluftslivsutövande i syfte att förstå dessa drivkrafter i relation till mänskliga behov. Studien bestod av 31 deltagare från olika delar av Sverige, i åldrarna 22-75 med varierande sysselsättning, friluftslivs-utbildning, civilstatus och nationalitet, varav 16 kvinnor. Data samlades in genom att deltagarna fick skriva berättelser om sin motivation. Det insamlade materialet meningskoncentrerades och analysen resulterade i att tre abstrakta motiv kunde urskiljas: (1) att komma bort från något, samt (2) att få inre och (3) yttre stimulans. Utövandet har visat sig tillfredsställa flertalet behov och främjar på så vis välmående. Vidare bidrar studien till kunskap om vad den friluftsaktiva individen upplever att hon behöver. Resultaten stämmer väl överens med tidigare forskning.

Prostate cancer is a clinically heterogeneous disease, with manifestations ranging from a rapid and often fatal progression, to indolent disease. Unfortunately, current clinicopathological criteria cannot differentiate men whose tumours require immediate and aggressive therapy from those in which active surveillance may be more appropriate. Both PTEN deletion and ETS gene fusions are biomarkers with potential to aid in prostate cancer clinical management. In this thesis, I postulate that PTEN and fusion gene rearrangements may be associated with specific genomic changes, and might also have general impact on the genomic landscape of prostate cancer. A meta-analysis of somatic copy number alterations (CNAs) examined 662 unique prostate cancer patient samples consisting of 546 primary and 116 advanced tumours derived from eleven publications. Normalization, segmentation and identification of corresponding CNAs for meta-analysis were achieved using established commercial software. The CNA distribution in primary disease was characterized by losses at 2q, 3p, 5q, 6q, 8p, 12p, 13q, 16q, 17p, 18q and 10q (PTEN), and acquisition of 21q deletions associated with the TMPRSS2:ERG fusion rearrangement. Unsupervised analysis identified five genomic subgroups. Parallel analysis of advanced and primary tumours indicated that PTEN genomic deletions and the gene fusion were enriched in advanced disease. A supervised analysis of PTEN deletions and gene fusions demonstrated that PTEN deletion was sufficient to impose higher levels of CNA. Moreover, the overall percentage of the genome altered was significantly higher when PTEN was deleted, suggesting that this important genomic subgroup was likely characterized by intrinsic chromosomal instability. Candidate genes in each of the recurrent CNA regions characteristic of each subgroup showed that signalling networks associated with cancer progression and genome stability were likely to be perturbed at the highest level in the PTEN deleted genomic subgroup. Therefore classification of primary prostate cancer according to PTEN deletions, but not the gene fusion, was associated with greatly increased levels of CNA. Collectively, the impact of PTEN loss resulted in a significantly greater frequency and extent of alteration, and heightened genomic instability with concomitant pathway disruptions. / Thesis (Ph.D, Pathology & Molecular Medicine) -- Queen's University, 2014-04-29 14:20:06.02

Les tumeurs locales de la prostate sont associées à une évolution lente et une bonne survie, alors que les stades plus avancés révèlent dans 80% des cas des métastases osseuses incurables. La découverte de gènes de fusion issus de remaniements chromosomiques, tel que TMPRSS2:ERG dans plus de 50% des cas, a ouvert une nouvelle voie dans la compréhension du processus de cancérisation de la prostate. La présence de ce gène de fusion peut être associée à un mauvais pronostic dans de nombreuses études cliniques. Cependant, son rôle précis au cours de la cancérisation et de la progression du cancer de la prostate reste à déterminer. Le gène Erg (Ets related gene) code un facteur de transcription dont l’expression est notamment associée à la mise en place du cartilage, et plus largement du squelette. Ceci suggère un rôle potentiel du gène de fusion impliquant ce facteur, et de ses gènes cibles, dans la formation des métastases osseuses du cancer de la prostate.Pour notre étude, nous avons utilisé des lignées de cellules tumorales prostatiques PC3 et PC3c, exprimant stablement le gène de fusion TMPRSS2:ERG et précédemment établies au laboratoire. Dans un premier temps, en utilisant un modèle d’injections intratibiales chez les souris SCID, nous avons démontré que l’expression ectopique de la fusion améliore la capacité d’induction de lésions ostéocondensantes en inhibant l’ostéolyse dans le modèle PC3 ostéolytique, et en stimulant l’ostéoformation dans le modèle PC3c mixte (ostéolytique et ostéocondensant). Cette expression ectopique de la fusion augmente également l’ostéomimétisme dans les deux modèles cellulaires, c’est-à-dire l’acquisition d’un phénotype semblable aux cellules osseuses leur conférant des avantages de survie et de propagation dans la moelle osseuse. En outre, trois nouveaux gènes cibles de TMPRSS2:ERG ont été mis en évidence : ET-1 (Endothelin-1), stimulant la différenciation ostéoblastique et inhibant la résorption osseuse ostéoclastique, ALPL (Alkaline Phosphatase Liver/Bone/Kidney), marqueur de différenciation des ostéoblastes, et COL1A1 (Collagen Type 1 Alpha 1), composant de la matrice osseuse, témoignant d’un rôle du gène de fusion dans la formation de métastases ostéocondensantes du cancer de la prostate.Par ailleurs, deux autres gènes ont été étudiés, codant soit une protéine impliquée dans la stabilisation de structures particulières appelées invadopodes, soit une protéine impliquée dans le métabolisme des lipides. L’ensemble de ces résultats contribue à mieux comprendre les mécanismes de cancérisation et d’évolution métastatique du cancer de la prostate, en particulier l’influence de l’expression du gène de fusion TMPRSS2:ERG dans les métastases osseuses du cancer de la prostate. / Local prostate cancers are associated with slow progression and good survival, while advanced stages reveal incurable bone metastases in 80% of cases. The discovery of fusion genes resulting from chromosomal rearrangements, such as TMPRSS2:ERG in more than 50% of cases, opened a new way in understanding the process of prostate cancer. The presence of this fusion gene may be associated with poor prognosis in many clinical studies. However, its precise role during cancerization and progression of prostate cancer remains to be determined. The Erg gene (Ets related gene) encodes a transcription factor whose expression is associated in particular with embryonic skeleton development. This suggests a potential role of the fusion gene involving this factor, and its target genes, in the formation of prostate cancer bone metastases.In this study, we used prostate cancer cell lines PC3 and PC3c, stably expressing the TMPRSS2:ERG fusion gene and previously established in the laboratory. First, using a model of intratibial injections in SCID mice, we demonstrated that ectopic expression of the fusion enhances the ability to induce osteoblastic lesions by inhibiting osteolysis in the osteolytic PC3 model, and by stimulating osteoformation in the mixed PC3c model (osteolytic and osteoblastic). This ectopic expression of the fusion also increases osteomimicry in both cell models, meaning the acquisition of a bone-cell-like phenotype which gives them advantages of survival and spread in the bone marrow. In addition, three new TMPRSS2:ERG target genes have been described: ET-1 (Endothelin-1), stimulating osteoblastic differentiation and inhibiting osteoclastic bone resorption, ALPL (Alkaline Phosphatase Liver/Bone/Kidney), a marker of the osteoblasts differentiation, and COL1A1 (Collagen Type 1 Alpha 1), a component of the bone matrix, providing novel insights into the role of the fusion gene in the formation of osteoblastic metastases of prostate cancer.In addition, two other genes have been studied, encoding either a protein involved in the stabilization of particular structures called invadopodia, or a protein involved in lipid metabolism.All these results contribute to decipher the mechanisms of cancerization and metastatic progression of prostate cancer, in particular the influence of the expression of TMPRSS2:ERG fusion gene in prostate cancer bone metastases.

Electroretinagram (ERG) is the recording of electrical activity of retinal cells elicited by light stimulation, which has been widely used to help diagnose different types of retinal dysfunctions. The ERG response signal is a short non-stationary signal that contains overlapping components. Different Digital Signal Processing (DSP) techniques are investigated using MATLAB to study the time-frequency responses of the ERG signal such as Short Time Fourier Transform (STFT), Continuous Wavelet Transform (CWT) and Discrete Wavelet Transform (DWT). The Photopic ERG signal was processed and analyzed in this thesis and the results of each technique have been investigated in detail. The Photopic ERG components have been extracted using DWT and ERG Models.

BACKGROUND: Many different ocular diseases produce a common symptom of macular edema - a leakage of fluid into the retina. In addition to the presence of this structural aberration, functionally, the retina’s capacity to effectively conduct electrochemical signals will be impaired. The impediment can be demonstrated by a decreased electrical response measured via electroretinography (ERG) and visualized as a waveform with quantifiable amplitude. Macular edema and its associated effects on retinal structure and function are resultant of abnormal blood vessel growth, or angiogenesis. The process of angiogenesis involves a pathway of multiple growth factors and signaling molecules, including vascular endothelial growth factor (VEGF). Modern day treatments to help resolve macular edema target VEGF in order to inhibit pathological angiogenesis; two such anti-VEGF medications are aflibercept, or Eylea, and bevacizumab, also known as Avastin. This retrospective cohort study aims to compare the outcomes of patients treated with either Avastin or Eylea, and to observe what structural or functional changes occur in each sample. METHODS: This study included twelve eyes of 8 eligible patients that were injected with intravitreal Avastin for diabetic macular edema (DME), clinically significant macular edema (CSME), proliferative diabetic retinopathy, or non-proliferative diabetic retinopathy (NPDR), and had resolved macular edema. Five eyes of 6 eligible patients that were injected with intravitreal Eylea for NPDR, neovascular age-related macular degeneration (AMD), cystoid macular edema (CME), central retinal vein occlusion (CRVO), or DME, and had resolved edema were also included in the study. Patient data was randomly screened and collected via the MDIntelleSys (MDI) electronic medical record system at Fromer Eye Centers, New York. No personally identifiable information was collected in this study. The parameters used for comparison of the two anti-VEGF medications were the length of treatment, frequency of injection, change in ERG magnitude between subsequent scans, and net change in ERG magnitude between the baseline scan and the most recent scan obtained during the period of the study. The means of each parameter were determined to be the best measure of central tendency to summarize the data. Welch’s t-tests were conducted at a significance level of α= 0.05 between the parameters of each group to determine the significance of the differences in the means obtained. RESULTS: There was no significant difference found between the mean number of injections, time until recovery, change in magnitude, and net change in magnitude for both Avastin-treated patients and those treated with Eylea. CONCLUSION: The results of this study support the conclusion that both aflibercept and bevacizumab are comparably effective anti-VEGF treatments, in both relieving macular edema and restoring function in retinal cells. The similar outcomes observed in each treatment group offer insight into the versatility of anti-VEGF treatment and provide physicians with the flexibility of pursuing alternative medication options for their patients. Further study into the structural and functional effects of various anti-VEGF medications is needed to account for variables such as age, sex, race, or other possibly confounding factors. An inclusion of other quantifiable data such as visual acuity would also benefit this investigation. Furthermore, this study is limited by its focus solely on anti-VEGF medication; this subject of discussion would benefit from an experimental comparison between anti-VEGF treatments and other allopathic interventions. Recent studies have suggested alternatives to anti-VEGF altogether such as intravitreal triamcinolone acetonide and intravitreal steroids like dexamethasone, marketed as Ozurdex.