The mechanism by which prostate cancer progresses from androgen dependence (AD) to androgen independence/castration resistance (AI/CR) is currently a major focus of prostate cancer-related research. Prostate cancers that progress to a state of AI/CR are typically resistant to most standard types of treatments. Due to its primary role in driving normal prostate cell growth and proliferation, the androgen receptor (AR) is believed to play a key role in progression. Coregulators, or any proteins which may either enhance or abrogate AR activity, are considered to be one of the potential mechanisms by which AR function may become impaired. Cyclin G-associated kinase (GAK) was initially identified as a potential coregulator of AR in a Tup 1 repressed transactivation system. A LNCaP cDNA library was screened for proteins which interacted with the NH2-terminus of AR. GAK was isolated from three independent library clones using two different AR baits (AR 1-549 and AR 1-646). This interaction was confirmed via GST pulldown and coimmunoprecipitation experiments, and preliminary luciferase assays suggested that GAK activates AR in a hormone dependent manner. In this study, my objectives were to validate GAK’s role as a coregulator of AR and to determine if overexpressing GAK affects progression to AI. In vitro luciferase assays whereby GAK was either overexpressed or knocked down in both LNCaP and PC3 cells did not significantly affect AR activity. Xenograft experiments utilizing a doxycycline (DOX) inducible lentiviral LNCaP-GAK overexpressing stable cell line demonstrated that while GAK may not play a significant role in modulating AR activity, it may adopt a more subtle role enhancing tumour take and tumour volume growth rate in vivo. While these results could not confirm GAK to be a direct coregulator of AR, it is entirely possible that GAK may influence prostate cancer progression, albeit indirectly. Recent publications report a growing amount of evidence suggesting GAK’s involvement in the critical cellular process of clathrin coated vesicle endocytosis, the dysregulation of which could potentially indirectly affect AR regulated genes.

Numerous studies have demonstrated that tumour cells have the ability to alter immune function to create an immune suppressed environment. This allows tumour cells to escape immune surveillance and consequently the tumour can progress. Dendritic and T cells have critical roles in immune activation and tolerance and are thus major targets of tumour-mediated immune suppression. Understanding the mechanism(s) by which tumour cells modulate the immune system will facilitate the development of immune system-based therapies for cancer treatments. In this study we sought to determine the nature of, and cellular and molecular mechanisms underlying, changes in immune status during tumour progression using mouse models of prostate cancer. Detailed analysis of the immunological status in a mouse prostate dysplasia model (12T-7slow) revealed that immune suppression accompanied tumour progression. We found that T cells isolated from tumour-bearing hosts were hypo-responsive to antigen stimulation. Furthermore, we demonstrated that CD4+CD25+ regulatory T cells were responsible, at least in part, for this alteration. Anti-CD25 antibody treatment reduced, but did not prevent, tumour growth in either a transplanted prostate tumour model or a spontaneously developing prostate tumour model. In addition, an altered dendritic cell phenotype and an elevated frequency of CD4+CD25+ regulatory T cells were observed within the tumour mass. Similar alterations were observed in the prostate-specific Pten knockout mice which develop advanced prostate adenocarcinoma. Interestingly, evidence of immune activation, such as an increased frequency of activated T cells, was detected in the tumour microenvironment in both mouse prostate tumour models. To identify factors that may play critical roles in the altered immune cell phenotype observed in the tumour microenvironment, a global gene expression profiling analysis was carried out to evaluate the changes in immune-related gene expression patterns. This analysis provided additional evidence for the co-existence of immune suppression and immune activation. Moreover, subsequent analyses suggested that one differentially expressed transcript, interferon regulatory factor 7, and its target genes might be involved in modulating immune cells and/or tumour progression. Taken together, these studies have important implications for designing specific and effective anti-tumour immune therapy strategies that involve manipulation of tumour cells, dendritic cells and regulatory T cells.

Prostate cancer is the most commonly diagnosed cancer in Canadian males, and is the third most common cause of cancer related deaths with decreasing mortality in men. Previous studies have suggested that an increased risk of prostate cancer among men may be associated with rural environment. The etiology of prostate cancer is not precisely known among men in rural Saskatchewan. We investigated the prevalence of prostate cancer and the putative relationship between rural exposures (occupational i.e. farming and environmental), personal smoking history, family history of cancer and prostate cancer. A baseline mail out survey was conducted in 2010-2011 of 11,982 households located in four geographic regions (South West, South East, North West, and North East) of Saskatchewan, Canada. Completed questionnaires were obtained from 4,624 households (8,261 individuals). The questionnaires collected information on individual (demographic factors, exposure to pesticides including insecticides, herbicides and fungicides) and contextual (household characteristics such as income, smoking) determinants from a rural population. In total 2,938 males (114 prostate cancer cases) were included for this analysis who were older than 45 years. Logistic regression analysis was used to analyze the relationship between independent variables and prostate cancer. Among prostate cancer cases, 46% of men lived on farms of rural Saskatchewan. The age standardized prevalence of prostate cancer was 3.32% (3.81% (n=52) and 2.95% (n=61) among farm and non-farm resident men). Farming job and farming duration did not have a statistically significant association with prostate cancer. A trend was observed for men who had work place exposure to insecticides and fungicides collectively and radiation to have an increased risk in comparison to men without these exposures. Personal smoking history, history of smoking pack years and family history of cancer modified the relationship between residence and prostate cancer. Age of an individual (≥ 65 years) was the strongest and most consistent risk factor of prostate cancer. Other factors such as marital status, household income adequacy, history of cardiovascular disease may also be associated with prostate cancer. The results may help research professionals by directing the focus of their research towards rural population examining prostate cancer.

Darbo tikslas. Atsitiktinės atrankos perspektyviniame klinkiniame tyrime nustatyti ir palyginti lokalaus priešinės liaukos vėžio įprastai frakcionuoto (CFRT) ir hipofrakcionuoto (HFRT) išorinio trimačio konforminio spindulinio gydymo sukeliamas ūmines spindulines reakcijas, gydymo efektyvumą, bei lėtines spindulines reakcijas. Tyrimo medžiaga ir metodai. CFRT taikyta 44 pacientams, švitinta prostata ir sėklinių pūslelių pagrindas 37 frakcijos po 2,0 Gy iki suminės 74 Gy dozės. HFRT taikyta 47 pacientams, toks pat taikinys švitintas 13 frakcijų po 3,0 Gy ir 4 frakcijos po 4,5 Gy iki suminės 57 Gy dozės. Pacientai stebėti mažiausiai 2 metus. Rezultatai. Ūminių 2 laipsnio šlapimo pūslės spindulinių reakcijų buvo statistiškai reikšmingai mažiau HFRT pacientų grupėje. Visų tiesiosios žarnos ūminių spindulinių reakcijų trukmė buvo mažesnė HFRT grupėje . Lėtinių šlapimo pūslės ir tiesiosios žarnos spindulinių reakcijų dažnumas pacientų grupėse nesiskyrė. Biocheminio atsako į gydymą dydis ir greitis pacientų grupėse per 2 metų stebėjimo laiką nesiskyrė. Išvados. Taikytas hipofrakcionuotas išorinis lokalaus prostatos vėžio spindulinis gydymas yra saugus, tačiau atokiam šio gydymo metodo efektyvumui nustatyti reikalingas ilgesnis pacientų stebėjimo laikas. / The aim of the study. To investigate and compare toxicity and efficacy of conventionally fractionated (CFRT) vs. hypofractionated (HFRT) three dimensional conformal external beam radiotherapy for localized prostate carcinoma within prospective randomized study. Matherial and Methods. Forty-four patients in the CFRT treatment arm were irradiated with 74 Gy in 37 fractions (2 Gy per fraction), and 47 in the HFRT arm were treated with 57 Gy, given in 13 fractions of 3 Gy plus 4 fractions of 4.5 Gy. The clinical target volume includes the prostate and a base of seminal vesicles. A minimum follow-up was 2 years. Results. The only grade 2 genitourinary acute toxicity proportion was significantly lower in the HFRT arm. The median duration of overall gastrointestinal acute toxicity was significantly shorter with HFRT. There were no statistically significant differences in the late toxicity rates, biochemical tumor response rates and time to the response between study arms during 2 year follow-up. Conclusions. The investigated hypofractionated 3DCRT for localized prostate carcinoma found to be safe, but extended follow-up is needed to justify the efficacy of our fractionation schedule in the long term.

Objectives: Men who receive androgen deprivation therapy (ADT) for prostate cancer (PCa) are at risk of several adverse effects that can be detrimental to both their physical and mental health. Common adverse effects include weight gain, muscle wasting, cardiovascular morbidity, fatigue and impaired quality of life (QOL). This study tested whether a combined aerobic and resistance exercise program can alleviate some of these symptoms in men receiving ADT. Design: Men with PCa, aged 50-80 years, receiving ADT were recruited to participate in this prospective randomized controlled trial. Subjects were assigned to a usual care group (UCG) or an exercise intervention group (EIG). The EIG completed a 16 week combined aerobic and resistance exercise program. Outcomes measures were assessed at baseline, 16 weeks, and 24 weeks and included: cardio-respiratory fitness; muscle strength and endurance; body composition; and reports of QOL, fatigue, mood, partner relations, and exercise behaviour. Results: Fifteen men were recruited to this study, but two participants in the EIG did not finish the study leaving the EIG with an n = 6 and the UCG with an n = 7. The exercise program did not lead to changes in weight, BMI or body fat. There was a small, close to significant, increase in muscle mass in the EIG over the intervention period (p = 0.052). This is encouraging as it demonstrates that exercise can counteract the catabolic effects of ADT. Interestingly, cardio-respiratory fitness improved over the course of the study for both groups. Muscular fitness, however, improved only for the EIG. There was a significant difference in chest press strength (p = 0.041) and leg press strength was bordering significance (p = 0.058). Unexpectedly, QOL declined for both groups during the intervention (p = 0.029). Participants in both groups also reported increased levels of fatigue from baseline to 24 weeks, although these changes were not significant (p = 0.586). Mood worsened over the study period for both groups from baseline to 16 weeks, but this increase in anxiety and depression was reduced at the follow-up period. These changes, too, were not significant (p = 0.364). Reports of partner relationships trended towards lower scores from baseline to 16 weeks. The men’s report in both groups and the women’s report in the EIG improved at the 24 week mark, but women in the UCG experienced further decline. Surprisingly, participants in both groups reported increases in exercise behaviour from baseline to 24 weeks. This could account for the lack of difference found in many of the measures. The power of this study was 0.22. Conclusion: Although this was a small study, it showed that a combined aerobic and resistance exercise program can have some positive benefits for men with PCa who are receiving ADT. Larger trials are needed to further examine the role of exercise in ameliorating the side effects of ADT, particularly in the areas of mood and partner relationships.

Background: We evaluated the validity of a set of 11 quality indicators for prostate cancer radiotherapy and radical prostatectomy by examining their association with outcomes. The selected indicators were: hospital volume, pre-treatment risk assessment, patient consultation with a radiation oncologist, appropriate follow-up care, leg immobilization during radiotherapy, bladder filling during radiotherapy, portal film target localization, use of nerve sparing surgery, operative blood loss, margin status and pelvic lymph node dissection. The selected outcomes were: cause-specific survival, disease-free survival, late morbidity (urinary incontinence, gastrointestinal and genitourinary morbidity), change in node stage from clinical N0 to pathologic N1, and margin status. Methods: Our study sample consisted of 1570 prostate cancer patients who were diagnosed in Ontario between January 1, 1990 and December 31, 1998 who received radical prostatectomy within 6 months of diagnosis (n=646), or curative radiotherapy within 9 months of diagnosis (n=924). Quality of care, outcomes, and potential confounders were measured using patient chart and administrative data. Regression techniques were used to evaluate the associations between quality indicators and relevant outcomes. Results: For patients treated surgically, hospital volume met our test of validity. Patients treated in the lowest volume hospital (0-1 RP/month) were at greater risk of prostate cancer death than patients treated in the highest volume hospitals (7+ RP/month) (HR=5.37 95% CI=1.23-23.46). For patients treated with radiotherapy, leg immobilization and bladder filling during radiotherapy met our test of validity. Patients treated without leg immobilization were more likely to experience urinary incontinence (RR=2.18, 95% CI=1.23-3.87) and genitourinary late morbidities (RR=1.72, 95% CI=1.16-2.56) than patients who received leg immobilization. Patients who were treated with an empty bladder were more likely to experience GU late morbidities (RR=1.98, 95% CI=1.08-3.63) than those treated with a full bladder. The remaining indicators did not meet our test of validity. Conclusion: Our results support the validity of one surgical quality indicator and two radiotherapy quality indicators. Explanations for our non-significant findings, including limited study power, data quality, our definition and measurement of indicators, and a true failure to predict outcome(s) are discussed, and recommendations for further research are presented. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2011-09-07 20:26:34.461

The purpose of the research was to investigate the potential for converting agricultural by-products, barley hull and flaxseed hull as well as their co-extract, into value-added functional food ingredients. Four varieties of barley hull and 3 types of flaxseed hull were hydrolyzed in calcium hydroxide solution in a water bath at 70°C for 4 hrs with shaking. The major phenolic compounds in barley hull, flaxseed hull and their co-extracts were identified by reversed phase high performance liquid chromatography (HPLC) coupled with photodiode array detection (PAD) and quadrupole - time of flight (Q-TOF) mass spectrometry (LC-MS). Ferulic acid, p-coumaric acid, vanillic acid and vanillin, and four ferulate dehydrodimers were detected in barley hull and their co-extracts. Quantitative analysis was conducted on the phenolic acids using the available standards. However, the phenolic compounds in flaxseed were found to be distinct from that of barley hull. Large amounts of secoisolariciresinol diglucoside (SDG), ferulic acid glucoside (FeAG), p-coumaric acid glucoside (CouAG) were found in flaxseed hull with minor content of caffeic acid glucoside (CAG) and flavonoids herbacitin glucoside (HDG), whereas the phytochemical profile of the co-extract was enriched by combining major phenolic compounds from both barley hull and flaxseed hull.The antioxidant activity of barley hull, flaxseed hull as well as their co-extract was evaluated using DPPH radical scavenging assay while total phenolic content was measured using the Folin-Ciocalteau method. After screening using chemical assays, the representative barley hull extract, flaxseed hull extract as well as their co-extract were tested for their intracellular antioxidant activity and the antiproliferative activity in PC-3 human prostate cancer cells. Both chemical assays and the cell culture assays indicated that barley and flaxseed hull had strong antioxidant activity and antiproliferative activity. Although the co-extract exhibited the strong antioxidant activity in the chemicals assay, it behaved differently in the cell culture assay, which may be attributed to the chemical and biological properties of the major phenolics in the co-extract.Following evaluation of the antioxidant activity and anticancer effect of barley hull extract, flaxseed hull extract as well as their co-extract, each type of extract was incorporated into Chinese steamed bread (CSB). The phytochemical profile of CSB was enriched by incorporating barley hull extract, flaxseed hull extract as well as their co-extract, which resulted in a significant enhancement in the antioxidant activity evaluated by DPPH and ORAC. Therefore, barley hull, flaxseed hull and their co-extract are suggested as promising sources of functional food ingredients.

Cofilin’s activity to nucleate actin filament assembly, is regulated by phosphorylation at a single site on the amino terminus, Serine 3. Phosphorylation at this site abolishes the ability of ADF/cofilin to bind to F-actin and inhibits its severing function. This work characterizes the ability of dephosphorylated cofilin (mutation at Serine 3 site) to navigate prostate cancer actin cytoskeleton and metastatic properties in response to TGF-β. TGF-β increased Lim Domain Kinase 2 (LIMK-2) activity leading to cofilin phosphorylation and decrease actin filament severing in wild type cofilin (WTCFL) PC-3 cells. Constitutively active cofilin in Serine 3 cofilin mutants (S3ACFL) promoted prostate cancer cell filopodia formation, actin severing and directed TGF-β mediated migration and invasion. Co-culture of prostate cancer cells with prostate cancer associated fibroblasts induced cell invasion in WTCFL and S3ACFL cells. Active cofilin further enhanced the invasive response, even in the presence of a TGF-β-neutralizing antibody, implicating the contribution of the microenvironment. Active cofilin led to a significant increase in prostate cancer cell metastatic potential in vivo and cofilin correlated with metastasis in a mouse model of prostate tumor progression. In human prostate cancer, cofilin expression was significantly higher in metastasis compared to the primary tumors. Cofilin thus emerges as a regulator of the actin cytoskeleton remodeling capable of coordinating the cellular responses to TGF- β towards prostate cancer metastasis. Understanding how cancer cells interprete TGF-β signals from the microenvironment, is critical for defining the mechanism via which TGF- β function is switched from a growth suppressor to a metastasis promoter. Here we show that in prostate cancer, TGF-β action is directed by active cofilin enabling actin cytoskeleton changes and metastatic behavior. The significant association of cofilin with prostate cancer metastatic progression supports its predictive and targeting value in metastasis.

The development of prostate tumors has been linked to co-morbid diabetes mellitus (DM) in several studies, potentially through the stimulation of insulin-like growth factor receptor (IGFR). This study evaluates the effect of anti-diabetic medication use on the development of high grade tumors and time to tumor progression compared to non-diabetics. This retrospective, nested case control study identified patients with prostate cancer (PCa) from the Kentucky Medicaid Database. Cases were diagnosed with PCa and DM and using at least one of the following antidiabetic medications; sulfonylureas, insulin, metformin or TZDs. Cases were further stratified on their insulin exposure resulting from therapy. Controls were those with PCa without DM or any anti-diabetic medications. No statistically significant effects on insulin exposure was found on tumor grade and time to progression. Trends identified that use of metformin or TZDs potentially decreased the odds of high-grade tumors and decreased the risk of progression, while sulfonylureas and high-dose insulin may increase the odds of high-grade tumors and increase the risk of progression compared to non-diabetics. Future studies should be conducted to further evaluate the effects of anti-diabetic medications on tumor grade and time to prostate cancer progression.

Access to abstract permanently restricted to Ball State community only. / Literature review -- Interaction of radiation with matter -- Radiation dosimetry -- Materials and methods -- Results -- Discursion. / Access to thesis permanenty restricted to Ball State community only. / Department of Physics and Astronomy