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Role Of High Molecular Weight Hyaluronan In Ultraviolet B Light-Induced Transformation, Katelyn Cousteils Oct 2017

Role Of High Molecular Weight Hyaluronan In Ultraviolet B Light-Induced Transformation, Katelyn Cousteils

Electronic Thesis and Dissertation Repository

Keratinocyte carcinomas (KCs) are the most common cancers globally. Ultraviolet light is the key risk factor for these cancers but sunscreen has proven ineffective in their prevention, indicating a need for new prophylactic agents. Chronic elevation of high molecular weight (HMW) tissue hyaluronan (HA) in skin is linked to tumor resistance in the naked mole rat. To directly assess the role of this polysaccharide in resistance to keratinocyte tumors, a HMW HA phosphatidylethanolamine (HA-PE) formulation that penetrates skin and accumulates as coats around keratinocytes was prepared. The tumor resistance properties of the HA-PE formulation were tested in a mouse model …


Characterization Of Plant-Spider Mite Interactions And Establishment Of Tools For Spider Mite Functional Genetic Studies, Nicolas Bensoussan Oct 2017

Characterization Of Plant-Spider Mite Interactions And Establishment Of Tools For Spider Mite Functional Genetic Studies, Nicolas Bensoussan

Electronic Thesis and Dissertation Repository

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most polyphagous herbivores feeding on cell contents of over 1100 plant species including more than 150 crops. However, despite its important pest status and a growing understanding of the molecular basis of its interactions with plant hosts, knowledge of the way mites interface with the plant while feeding and the plant damage directly inflicted by mites is lacking. Likewise, while the use of the reverse genetic tools in plants facilitated our understanding of the establishment of defense mechanisms against spider mite herbivory, such tools are lacking for …


Characterization Of Acaricide Resistance, Plant-Mediated Rnai Against Two-Spotted Spider Mites (Tetranychus Urticae Koch), And Assessing Off- And Non-Target Effects, Hooman Hosseinzadeh Namin Oct 2017

Characterization Of Acaricide Resistance, Plant-Mediated Rnai Against Two-Spotted Spider Mites (Tetranychus Urticae Koch), And Assessing Off- And Non-Target Effects, Hooman Hosseinzadeh Namin

Electronic Thesis and Dissertation Repository

The two-spotted spider mite (TSSM), Tetranychus urticae (Koch), is one of the most damaging agricultural pests in the world. It feeds on over 150 crops, causing considerable yield losses in greenhouses and agricultural fields. Currently, using synthetic acaricides is the main method to control TSSM. However, it can develop resistance to acaricides with repeated exposure, and typically resistance can occur within two to four years. To understand the underlying mechanisms of spider mite adaptation to acaricides is an essential part of resistance management strategy. The resistance ratio of the pyridaben-selected strain compared with the pre-selection strain was estimated at greater …


The Effect Of Diet On Midgut And Resulting Changes In Infectiousness Of Acmnpv Baculovirus In Trichoplusia Ni, Elizabeth Chen Sep 2017

The Effect Of Diet On Midgut And Resulting Changes In Infectiousness Of Acmnpv Baculovirus In Trichoplusia Ni, Elizabeth Chen

Electronic Thesis and Dissertation Repository

The cabbage looper, Trichoplusia ni, a global generalist lepidopteran pest, has developed resistance to many synthetic and biological insecticides, requiring effective and environmentally acceptable alternatives. One possibility is the Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). This baculovirus is highly infectious for T. ni, with potential as a biocontrol agent, however, its effectiveness is strongly influenced by dietary context. In this study, microscopy and transcriptomics were used to examine how the efficacy of this virus was affected when T. ni larvae were raised on different diets. Larvae raised on potato host plants had lower chitinase and chitin deacetylase transcript levels …


Regulation Of C-Raf Stability By The Ranbpm/Ctlh Complex, Christina J. Mctavish Sep 2017

Regulation Of C-Raf Stability By The Ranbpm/Ctlh Complex, Christina J. Mctavish

Electronic Thesis and Dissertation Repository

RanBPM is an evolutionarily conserved multi-domain protein that has been implicated in the regulation of several cellular process, including protein stability, cell migration, gene transcription, and apoptosis. RanBPM is identified as a key member of the CTLH complex, an orthologous complex to a yeast E3 ubiquitin ligase complex, the exact function of which remains unknown. Previously, our laboratory identified RanBPM as an inhibitor of the ERK1/2 pathway through the modulation of C-RAF protein levels. This study shows that RanBPM-mediated degradation of C-RAF occurs through the proteasome and the entire CRA domain of RanBPM is necessary for direct interaction with C-RAF …


Intracellular Signalling Crosstalk In The Differentiation Of F9 Cells Into Extraembryonic Endoderm, Tina Nicole Cuthbert Aug 2017

Intracellular Signalling Crosstalk In The Differentiation Of F9 Cells Into Extraembryonic Endoderm, Tina Nicole Cuthbert

Electronic Thesis and Dissertation Repository

Mouse F9 cells differentiate into primitive extraembryonic endoderm (PrE) with retinoic acid (RA) treatment, resulting in up-regulation of Gata6, which when translated directly activates Wnt6. Canonical Wnt signalling is required for PrE differentiation, and this, like most developmental processes, requires input from one or more additional pathways, including hedgehog (Hh). The Hh pathway is regulated by GATA6, and crosstalks positively/negatively with Wnt signalling. Ihh up-regulation in F9 cells accompanies PrE induction, but a role for GATA6 or Hh pathway activation in obligatory Wnt/ß-catenin signalling is not known. To address this, I show that RA induces Ihh and altered expression of …


Contribution Of Activating Transcription Factor 3 To Development Of Acinar-To-Ductal Cell Metaplasia, Jelena Toma Aug 2017

Contribution Of Activating Transcription Factor 3 To Development Of Acinar-To-Ductal Cell Metaplasia, Jelena Toma

Electronic Thesis and Dissertation Repository

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer death in North America. The highest risk factor for PDAC is recurrent pancreatitis. While the link between PDAC and pancreatitis is unknown, de-differentiation of acinar cells is common to both diseases. Our lab has shown that Activating Transcription Factor 3 (ATF3), a factor upregulated during pancreatic injury, contributes to the development of acinar-to-ductal cell metaplasia (ADM), a precursor phenotype of PDAC. The goal of this study was to identify how ATF3 contributes to ADM. I hypothesize that ATF3 regulates acinar gene expression promoting ADM. We observed decreased ADM development …


Functional Characteristics Of Four Novel Lone Atrial Fibrillation-Linked Connexin40 Mutants, Mahmoud Noureldin Jul 2017

Functional Characteristics Of Four Novel Lone Atrial Fibrillation-Linked Connexin40 Mutants, Mahmoud Noureldin

Electronic Thesis and Dissertation Repository

Atrial fibrillation (AF) is the most common form of cardiac arrhythmia. Recently, four novel heterozygous Cx40 mutations, K107R, L223M, Q236H, and I257L were identified in 4 of 310 unrelated AF patients. To study possible alterations associated with these mutants, we studied their localization and function using gap junction (GJ)-deficient model cells. Cell pairs expressing Q236H alone or together with wildtype Cx43 showed a significantly lower coupling conductance. Impaired GJ function and dominant negative action on Cx43 of this mutant are consistent with previous findings on the majority of AF-linked Cx40 mutants. The remaining three novel AF-linked mutants did not show …


Inhibition Of Pannexin 1 Reduces Tumorigenic Properties Of Human Melanoma, Taylor J. Freeman Jul 2017

Inhibition Of Pannexin 1 Reduces Tumorigenic Properties Of Human Melanoma, Taylor J. Freeman

Electronic Thesis and Dissertation Repository

Pannexin 1 (PANX1) is a channel-forming glycoprotein that allows the passage of important signaling molecules, including ATP. We examined PANX1 levels in a panel of human melanomas and evaluated its potential as an effective target for melanoma therapy. We are the first to report endogenous PANX1 levels in multiple human melanoma cell lines, patient-derived melanoma biopsies, and primary melanoma cells. Treatment with two PANX1 channel blockers, Carbenoxolone (CBX) and Probenecid (PBN), on A375 and A375-MA2 melanoma cells significantly reduced cell growth and migration, and increased the production of melanin, a marker for a melanocytic-like phenotype. Daily treatment with CBX or …


The Role Of P62/Sqstm1 In Tgfβ-Dependent Emt And Autophagy, Evelyn Ng Jun 2017

The Role Of P62/Sqstm1 In Tgfβ-Dependent Emt And Autophagy, Evelyn Ng

Electronic Thesis and Dissertation Repository

Transforming growth factor beta (TGFβ) is a cytokine that regulates cellular adhesion, proliferation and apoptosis. In the context of cancer, TGFβ induces processes such as epithelial-to-mesenchymal transition (EMT). More recently, TGFβ has been discovered to also induce autophagy, and the relationship between TGFβ-induced EMT and autophagy remains unknown. Due to its involvement in autophagy and its established interactions with key TGFβ signaling proteins, this thesis focuses on the sequestosome 1 (p62/SQSTM1) protein. Here, I have shown that p62/SQSTM1 co-localizes with TGFβ receptors at the same time point that the receptors localize to Rab7-positive late endosomes. siRNA-mediated silencing of p62/SQSTM1 was …


The Role Of Cytoplasmic Polyadenylation Element Binding Protein -2 (Cpeb-2) In Human Breast Cancer, Joshua Tordjman Jun 2017

The Role Of Cytoplasmic Polyadenylation Element Binding Protein -2 (Cpeb-2) In Human Breast Cancer, Joshua Tordjman

Electronic Thesis and Dissertation Repository

Cyclooxygenase-2 (COX-2) is overexpressed in 40-50% of breast cancers, and promotes tumour progression through increased proliferation, migration, invasion, Epithelial-to-Mesenchymal Transition (EMT), and induction of therapy-resistant Stem-Like-Cells (SLCs). COX-2 stimulates expression of two oncogenic and SLC-promoting microRNAs (miR-526b, miR-655), which simultaneously target one gene, Cytoplasmic Polyadenylation Element Binding Protein-2 (CPEB-2). Hypothesis: CPEB-2 is a tumour- and SLC-suppressing gene in breast cancer. Results: CPEB-2 knockout in a non-tumourigenic mammary epithelial cell line MCF10A demonstrated increases in proliferation, migration, invasion, EMT markers, SLC content, and VEGF-D expression. CPEB-2, an mRNA-binding translation-regulating protein, was found to regulate the translation of tumour suppressor p53. When …


The Loss Of Atrx Creates Susceptibility To Kras-Mediated Pancreatic Damage, Claire C. Young Jun 2017

The Loss Of Atrx Creates Susceptibility To Kras-Mediated Pancreatic Damage, Claire C. Young

Electronic Thesis and Dissertation Repository

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with a five-year survival rate of 8%. Oncogenic KRAS mutation is found in greater than 95% of PDAC cases, but additional mutations or injury are required for disease initiation and progression. Chromatin remodeling protein ATRX has been previously implicated in DNA repair, replication and maintaining genomic stability. I hypothesized that loss of ATRX could increase the susceptibility of pancreatic tissue to pancreatic injury or KRAS-mediated damage. In this study, combination of inducible ATRX loss in adult mice with recurrent pancreatic injury or oncogenic KRAS activation resulted in increased pancreatic damage, including fibrosis, …


Nuak1 Has Tumor Suppressive Activity In Epithelial Ovarian Cancer, Parima Saxena Jun 2017

Nuak1 Has Tumor Suppressive Activity In Epithelial Ovarian Cancer, Parima Saxena

Electronic Thesis and Dissertation Repository

NUAK1, a downstream substrate of the stress metabolism regulator Liver kinase B1 (LKB1), has been implicated as an oncogene and tumor suppressor, with distinct roles in cell cycle, senescence and cell adhesion. Epithelial ovarian cancer (EOC) spheroids remain dormant during intraperitoneal metastasis with reduced proliferation and metabolism to survive metabolically harsh conditions, possibly implicating a role of NUAK1 in EOC spheroid biology. I hypothesize that NUAK1 is regulated by LKB1 to promote dormancy in EOC. I demonstrate that NUAK1 expression and phosphorylation is regulated by LKB1 in EOC cell lines. NUAK1 is largely under-expressed in many established and new ascites-derived …


Cellular/Molecular Analysis Of Interspecies Sterile Male Hybrids In Drosophila, Rachelle L. Kanippayoor Jun 2017

Cellular/Molecular Analysis Of Interspecies Sterile Male Hybrids In Drosophila, Rachelle L. Kanippayoor

Electronic Thesis and Dissertation Repository

Over time, genetic differences can accumulate between populations that are geographically separated. This genetic divergence can lead to the evolution of reproductive isolating mechanisms that reduce gene flow between the populations and, upon secondary contact, result in distinct species. The process of speciation is, thus, what accounts for the multitude of species that contribute to the rich biodiversity on Earth. Interspecies hybrid sterility is a postzygotic isolating mechanism that affects the development of hybrids, rendering them sterile. A notable trend, known as Haldane's Rule, describes that heterogametic individual (e.g. males in Drosophila) are more susceptible to sterility than homogametic …


Regulation Of Smad Anchor Necessary For Receptor Activation (Sara) Protein Levels By The E3 Ubiquitin-Protein Ligase Smurf2 And Smad7, Sanghyun Lee May 2017

Regulation Of Smad Anchor Necessary For Receptor Activation (Sara) Protein Levels By The E3 Ubiquitin-Protein Ligase Smurf2 And Smad7, Sanghyun Lee

Electronic Thesis and Dissertation Repository

The TGFβ pathway, which regulates cell proliferation and differentiation, has also been shown to induce non-small cell lung cancer cell (NSCLC) migration and invasion. The TGFβ pathway is initiated through the binding of TGFβ to cell surface Ser/Thr kinase receptors. Activated receptors then phosphorylate intracellular signaling proteins, termed Smads, which translocate into the nucleus to regulate transcriptional responses. The protein Smad anchor for receptor activation (SARA) facilitates the phosphorylation of Smads and allows for efficient signal transduction. On the other hand, the inhibitory Smad, Smad7, recruits the E3 ubiquitin ligase, Smurf2, to catalyze the degradation of TGFβ receptors. Since the …


Alternative Splicing And Extra-Telomeric Role Of Telomerase Reverse Transcriptase Isoforms In Human Embryonic Stem Cells, Joohwan Kim May 2017

Alternative Splicing And Extra-Telomeric Role Of Telomerase Reverse Transcriptase Isoforms In Human Embryonic Stem Cells, Joohwan Kim

Electronic Thesis and Dissertation Repository

Human telomerase, a ribonucleoprotein complex consisting of a catalytic subunit (hTERT) and a RNA template component (TERC), prevents telomere attrition in human embryonic stem cells (hESCs) providing these cells with prolonged replicative capacity. Interestingly, hTERT has several alternatively spliced isoforms, most of which are catalytically inactive. One alternative splicing event involving a complete loss of exons 7 and 8 results in a catalytically inactive isoform called β-hTERT. The β-hTERT is highly expressed in certain cancer types and hESCs. Full-length hTERT (FL-hTERT) is known to translocate from nuclei to mitochondria when cells are exposed to either chronic (oxygen tension) or acute …


Cerebral Lactate Metabolism And Memory: Implications For Alzheimer's Disease, Richard Andrew Harris Apr 2017

Cerebral Lactate Metabolism And Memory: Implications For Alzheimer's Disease, Richard Andrew Harris

Electronic Thesis and Dissertation Repository

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by amyloid plaques that are comprised of aggregated amyloid-beta peptides. These toxic proteins promote mitochondrial dysfunction and neuronal cell death. A shift in metabolism away from oxidative phosphorylation and toward aerobic glycolysis, with the concomitant production of lactate, affords neurons a survival advantage against amyloid-beta toxicity. Recent evidence now suggests that aerobic glycolysis in the brain plays a critical role in supporting synaptic plasticity, learning, and memory. However, the role of aerobic glycolysis and lactate metabolism in AD-mediated cognitive decline is unknown. My objective was to test the hypotheses that aerobic glycolysis …


Characterizing Ferroportin Trafficking In Macrophages During Phagocytosis, Tayler J. Farrell Apr 2017

Characterizing Ferroportin Trafficking In Macrophages During Phagocytosis, Tayler J. Farrell

Electronic Thesis and Dissertation Repository

Macrophages are important mediators of innate immunity and nutritional immunity via modulation of essential nutrients like iron during bacterial infection. Ferroportin (Fpn), an iron-exporting protein, is found on the plasma membrane of macrophages and, if not modulated during phagocytosis, would transport iron into phagosomes and supply phagocytosed bacteria with iron. Interestingly, the fate of Fpn during phagocytosis and bacterial infection remains unknown. We generated a Fpn-GFP fusion protein and, using fluorescence microscopy, demonstrated that, during phagocytosis in RAW264.7 macrophages, Fpn is removed from phagosomes containing IgG-coated beads or Staphylococcus aureus. Further, Fpn is present on Rab5-containing phagosomes but absent …


Building Muscle: The Role Of Insulin-Like Growth Factor Binding Protein-6 And Insulin-Like Growth Factors In The Differentiation Of Placental Mesenchymal Stem Cells Into Skeletal Muscle, Doaa Aboalola Apr 2017

Building Muscle: The Role Of Insulin-Like Growth Factor Binding Protein-6 And Insulin-Like Growth Factors In The Differentiation Of Placental Mesenchymal Stem Cells Into Skeletal Muscle, Doaa Aboalola

Electronic Thesis and Dissertation Repository

Human placenta is a readily available source for isolation of adult mesenchymal stem cell (MSC), for potential use in regenerative therapies. MSC fate is influenced by the microenvironment in vivo, and insulin-like growth factors (IGFs) are critical components of the stem cell niche, as they regulate proliferation and differentiation into different lineages including bone, fat, and skeletal muscle. Insulin-like growth factor binding protein-6 (IGFBP-6), relative to other IGFBPs, has high affinity for IGF2 and is believed to be the main modulator of IGF-2 function. However, the role of IGFBP-6 in muscle development has not been clearly defined. In this …


Gatekeepers Of Nitrogen-Fixing Symbiosis: Cytokinin-Ethylene Crosstalk Regulates Symbiotic Interaction In Lotus Japonicus, Seyedehmandana Miri Apr 2017

Gatekeepers Of Nitrogen-Fixing Symbiosis: Cytokinin-Ethylene Crosstalk Regulates Symbiotic Interaction In Lotus Japonicus, Seyedehmandana Miri

Electronic Thesis and Dissertation Repository

Leguminous plants thrive under nitrogen-limited soil conditions because of their ability to symbiotically interact with nitrogen-fixing bacteria, known as rhizobia. In the presence of compatible strains of rhizobia, they develop specialized symbiotic organs, called root nodules, which host the bacteria and provide the appropriate conditions for symbiotic nitrogen fixation to occur. The plant hormone cytokinin is the key endogenous trigger for the inception of root nodule organogenesis. In the model legume Lotus japonicus, analysis of the cytokinin receptor gene Lotus histidine kinase 1 (Lhk1) showed that it is required and also sufficient for the initiation of nodule …


Investigation Of Chitosan-Based Hydrogels As A Cell Delivery Platform For Adipose-Derived Stem/Stromal Cell Transplantation To Promote Angiogenesis In Ischemic Tissues, Jobanpreet Singh Dhillon Mar 2017

Investigation Of Chitosan-Based Hydrogels As A Cell Delivery Platform For Adipose-Derived Stem/Stromal Cell Transplantation To Promote Angiogenesis In Ischemic Tissues, Jobanpreet Singh Dhillon

Electronic Thesis and Dissertation Repository

Stem cell transplantation is under investigation to stimulate angiogenesis in patients with peripheral artery disease. To develop a cell-delivery platform that enhances cell retention and function post-transplantation, the response of human adipose-derived stem/stromal cells (ASCs) encapsulated within N-methacrylate glycol chitosan (MGC) hydrogels with or without integrin-binding RGD or IKVAV motifs was explored. ASC viability was enhanced in the MGC and MGC-RGD hydrogels relative to the MGC-IKVAV group under hypoxic (2% O­2) culture conditions, with cell spreading and higher metabolic activity noted in MGC-RGD at 14 days. Analysis of angiogenic gene expression revealed similar patterns between all hydrogel …


The Effects Of Acetylenic Tricyclic Bis-(Cyano Enone) On Cell Migration, Eddie Chan Feb 2017

The Effects Of Acetylenic Tricyclic Bis-(Cyano Enone) On Cell Migration, Eddie Chan

Electronic Thesis and Dissertation Repository

Although cancer survival rates have significantly improved over the past few decades, the improvements are primarily due to early diagnosis and inhibiting cancer growth. Limited progress has been made in the treatment of cancer metastasis, which contributes to 90% of cancer related deaths, and therapeutic agents targeting the various aspects of metastasis are lacking. One potential approach is to utilize small pharmacological compounds to inhibit tumour cell motility, as a strategy against tumour cell migration, invasion, and metastasis. The acetylenic tricyclic bis-(cyano enone), TBE-31, has been shown to be a promising chemopreventative compound. However, its effects on cell migration are …


Mt1-Mmp Mediates The Migratory And Tumourigenic Potential Of Breast Cancer Cells Via Non-Proteolytic Mechanisms, Mario Cepeda Jan 2017

Mt1-Mmp Mediates The Migratory And Tumourigenic Potential Of Breast Cancer Cells Via Non-Proteolytic Mechanisms, Mario Cepeda

Electronic Thesis and Dissertation Repository

Membrane Type-1 Matrix Metalloproteinase (MT1-MMP) is a multifunctional protease that affects cell function via proteolytic and non-proteolytic mechanisms such as promoting degradation of the extracellular matrix (ECM) or augmentation of cell migration and viability, respectively. MT1-MMP has been implicated in metastatic progression ostensibly due to its ability to degrade ECM components and to allow migration of cells through the basement membrane. Despite in vitro studies demonstrating this principle, this knowledge has not translated into the use of MMP inhibitors (MMPi) that inhibit substrate catalysis as effective cancer therapeutics, or been corroborated by evidence of in vivo ECM degradation mediated by …


Discovery Of Novel Diagnostic Biomarkers On Prostate Tumor Microparticles For Discriminating Between Low And High Risk Prostate Cancer And Improving Prostate Cancer Screening, Sabine Brett Jan 2017

Discovery Of Novel Diagnostic Biomarkers On Prostate Tumor Microparticles For Discriminating Between Low And High Risk Prostate Cancer And Improving Prostate Cancer Screening, Sabine Brett

Electronic Thesis and Dissertation Repository

There are few protein-based biomarkers to accurately distinguish between patients with low risk prostate cancer from those with high risk disease in a non-invasive manner. Prostate specific antigen (PSA) is used for clinical follow-up of prostate cancer; however, it is not effective as a screening tool. As a result, many men with non-life threatening disease having to undergo unnecessary and painful biopsies. Therefore, there is a dire need for minimally invasive platforms for monitoring patients with clinically significant prostate cancer. Prostate cell microparticles (PCMPs) released by prostate epithelial cells into plasma are a potential source of biomarkers specific for prostate …