Open Access. Powered by Scholars. Published by Universities.®

Molecular Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

University of Louisville

Electronic Theses and Dissertations

Theses/Dissertations

Articles 1 - 30 of 33

Full-Text Articles in Molecular Biology

The Interplay Between Lung Adenocarcinoma, Nutrient Availability, And The Microbiome., Alexis A. Vega Dec 2023

The Interplay Between Lung Adenocarcinoma, Nutrient Availability, And The Microbiome., Alexis A. Vega

Electronic Theses and Dissertations

Lung cancer is one of the most common forms of cancer diagnosed, and has the highest lethality rate across all other forms of cancer in the U.S. While current therapeutic options include chemo-, immuno-, and radio-therapy, the benefits of caloric or nutrient restriction on cancer cells has also been investigated. Due to the many biological functions associated with methionine, many have proposed a methionine restricted diet would lead to favorable outcomes when combating cancer. Although our cells are incapable of synthesizing methionine, the bacteria found in our microbiome can. Furthermore, recent discoveries suggest an independent microbiome found within tumors that …


Epitranscriptomic Regulation In Breast Cancer And Pcb-Induced Liver Disease., Belinda Petri Aug 2023

Epitranscriptomic Regulation In Breast Cancer And Pcb-Induced Liver Disease., Belinda Petri

Electronic Theses and Dissertations

Post-transcriptional RNA modifications including N6-methyladenosine (m6A) regulate mRNA stability, splicing, and translation. My research examined m6A in two disease models: breast cancer (BCa) and non-alcoholic fatty liver disease (NAFLD). Acquired resistance to endocrine therapies (ET) develops in approximately 20% of BCa patients with estrogen receptor α positive (ER+) tumors following treatment. The mechanisms by which tumor cells evade ET are not completely understood. Using a cell line model, we investigated the role of an m6A reader protein, HNRNPA2B1 (A2B1) that is upregulated in ET-resistant ER+ BCa cells. Stable overexpression of A2B1 in ET-sensitive MCF-7 cells (MCF-7-A2B1), results in ET resistance, …


Re-Engineering Cardio-Oncology Testing Using Biomimetic Heart Slice Cultures., Jessica Miller Dec 2022

Re-Engineering Cardio-Oncology Testing Using Biomimetic Heart Slice Cultures., Jessica Miller

Electronic Theses and Dissertations

28% of drug withdrawal from the market are due to unforeseen disruptions in cardiomyocyte contractility and electrophysiology. The most commonly used platforms for drug testing are in vivo animal models and in vitro cell culture models. While both have been of paramount importance for the discovery and detection of many cardiotoxicities and mechanisms of action, they lack the ability to model an intact human myocardium. This work aims to establish cardiac tissue slices, which are 300-micron thin tissue sections taken from the left ventricular myocardium, as an alternative platform for cardio-oncology studies, specifically cardiotoxicity testing. Additionally, this work aims to …


Determination Of The Functional Role Of Rab-Ggt In Physcomitrium Patens., Hyun Jin Jung Aug 2022

Determination Of The Functional Role Of Rab-Ggt In Physcomitrium Patens., Hyun Jin Jung

Electronic Theses and Dissertations

Protein prenylation, a common lipid post-translational modification, is required for growth and development in eukaryotes. Rab geranylgeranylation involves the addition of one or two 20-carbon geranylgeranyl moieties to Rab-GTPase target proteins, which regulate intracellular vesicle trafficking. The reaction is carried out by heterodimeric Rab geranylgeranyltransferase (Rab-GGT), which is composed of two associated α- and β-subunits, with the assistance of an additional protein called Rab escort protein (REP). Loss of function of the Rab-GGT α subunit RGTA1 has not been reported in any plant. While knockout of either of the two β subunits RGTB1 or RGTB2 results in …


Applications Of Nuclear Magnetic Resonance Spectroscopy: From Drug Discovery To Protein Structure And Dynamics., Mark Vincent C. Dela Cerna Aug 2022

Applications Of Nuclear Magnetic Resonance Spectroscopy: From Drug Discovery To Protein Structure And Dynamics., Mark Vincent C. Dela Cerna

Electronic Theses and Dissertations

The versatility of nuclear magnetic resonance (NMR) spectroscopy is apparent when presented with diverse applications to which it can contribute. Here, NMR is used i) as a screening/ validation tool for a drug discovery program targeting the Phosphatase of Regenerating Liver 3 (PRL3), ii) to characterize the conformational heterogeneity of p53 regulator, Murine Double Minute X (MDMX), and iii) to characterize the solution dynamics of guanosine monophosphate kinase (GMPK). Mounting evidence suggesting roles for PRL3 in oncogenesis and metastasis has catapulted it into prominence as a cancer drug target. Yet, despite significant efforts, there are no PRL3 small molecule inhibitors …


A Computational Model Of The Line-1 Retrotransposon Life Cycle And Visualization Of Metabolic Networks In 3-Dimensions., Michael D. Martin Aug 2022

A Computational Model Of The Line-1 Retrotransposon Life Cycle And Visualization Of Metabolic Networks In 3-Dimensions., Michael D. Martin

Electronic Theses and Dissertations

Computational modeling of metabolic reactions and cellular systems is evolving as a tool for quantitative prediction of metabolic parameters and reaction pathway analysis. In this work, the basics of computational cell biology are presented as well as a summary of physical processes within the cell, and the algorithmic methods used to find time dependent solutions. Protein-protein and enzyme-substrate interactions are mathematically represented via mass action kinetics to construct sets of linear differential equations that describe reaction rates and formation of protein complexes. Using mass action methods, examples of reaction networks and their solutions are presented within the Virtual Cell simulation …


Cannabinoids And Retinal Fibrotic Disorders., Lucy June Sloan May 2022

Cannabinoids And Retinal Fibrotic Disorders., Lucy June Sloan

Electronic Theses and Dissertations

Retinal fibrosis is detrimental to vision. Retinal pigment epithelial (RPE) cells contribute to several retinal fibrotic diseases. Upon exposure to TGF-β, a key fibrotic cytokine, RPE cells trans-differentiate to myofibroblasts marked by the integration of α-SMA fibers into F-actin stress fibers, which confer strong contractility. Myofibroblasts produce and contract the collagen-rich fibrotic scar and disrupt retinal architecture. In this study, we investigated the in vitro effects of the putative endocannabinoid compound N-oleoyl dopamine (OLDA) on TGF-β2 induced porcine RPE cell contraction and α-SMA expression. Using an in vitro collagen matrix contraction assay, we found that OLDA inhibited TGF-β2 induced contraction …


Impact Of Pank1 Deletion On Mitochondrial Acetylation And Cardiac Function During Pressure Overload., Timothy N. Audam Dec 2021

Impact Of Pank1 Deletion On Mitochondrial Acetylation And Cardiac Function During Pressure Overload., Timothy N. Audam

Electronic Theses and Dissertations

Recent studies have associated elevated protein acetylation levels with heart failure in humans. Although mechanisms promoting elevated acetylation levels are not fully known, excess acetyl-CoA may drive enzyme-independent acetylation of cardiac proteins. Accumulation of acetyl-CoA depends on the availability of sufficient CoA, whose production is regulated by pantothenate kinases in the CoA biosynthetic pathway. We show that cardiac proteins are hyperacetylated during heart failure in humans and tested in mice whether limiting CoA abundance would improve ventricular remodeling during pressure overload-induced hypertrophy. We limited cardiac CoA levels by deleting the rate-limiting enzyme in CoA biosynthesis, Pank1 (one of three PANK-encoding …


Computational And Biochemical Characterizations Of Anhydrobiosis-Related Intrinsically Disordered Proteins., Brett R. Janis Dec 2021

Computational And Biochemical Characterizations Of Anhydrobiosis-Related Intrinsically Disordered Proteins., Brett R. Janis

Electronic Theses and Dissertations

Anhydrobiosis is the remarkable phenomenon of “life without water”. It is a common technique found in plant seeds, and a rare technique utilized by some animals to temporarily stop the clock of life and enter a stasis for up to several millennia by removing all of their cellular water. If this phenomenon can be replicated, then biological and medical materials could be stored at ambient temperatures for centuries, which would address research challenges as well as enhance the availability of medicine in areas of the world where refrigeration, freezing, and cold-chain infrastructure are not developed or infeasible. Furthermore, modifying crop …


Investigating A Novel Function For Phosphoserine Aminotransferase 1 (Psat1) In Epidermal Growth Factor Receptor (Egfr)-Mediated Lung Tumorigenesis., Rumeysa Biyik-Sit May 2021

Investigating A Novel Function For Phosphoserine Aminotransferase 1 (Psat1) In Epidermal Growth Factor Receptor (Egfr)-Mediated Lung Tumorigenesis., Rumeysa Biyik-Sit

Electronic Theses and Dissertations

Phosphoserine aminotransferase 1 (PSAT1) catalyzes the second enzymatic step within the serine synthetic pathway (SSP) and its expression is elevated in numerous human cancers, including non-small cell lung cancer (NSCLC). Epidermal growth factor receptor (EGFR) mutant NSCLC is characterized by activating mutations within its tyrosine kinase domain and accounts for 17% of lung adenocarcinomas. Although elevated SSP activity has been observed in EGFR-mutant lung cancer cells, the involvement of PSAT1 in EGFR-mediated oncogenesis is still unclear. Here, we explore a putative non-canonical function for PSAT1 using biochemical approaches to elucidate unknown interacting proteins and genomic RNA-seq profiling to identify cellular …


Investigation Of Phosphoserine Aminotransferase 1(Psat1) In Breast Cancer Progression., Stephanie Metcalf Dec 2019

Investigation Of Phosphoserine Aminotransferase 1(Psat1) In Breast Cancer Progression., Stephanie Metcalf

Electronic Theses and Dissertations

This dissertation describes my research into the involvement of phosphoserine aminotransferase 1 (PSAT1) in breast cancer progression; specifically, in triple negative breast cancer (TNBC) metastasis and endocrine resistance in estrogen receptor positive breast cancer (ER+BC). Breast cancer is the most common tumor diagnosis among women. While the overall 5-year survival for breast cancer is reaching 90%, the 5-year survival for metastatic disease is only 22%. Metastasis and endocrine resistance combined can affect over 50% of patients. One of the proteins and pathways implicated in both metastasis and endocrine resistance in breast cancer is phosphoserine aminotransferase 1 (PSAT1) and the serine …


Paraoxonase 2 Is Critical For Non-Small Cell Lung Carcinoma Proliferation., Aaron Whitt May 2019

Paraoxonase 2 Is Critical For Non-Small Cell Lung Carcinoma Proliferation., Aaron Whitt

Electronic Theses and Dissertations

Non-small cell lung carcinoma (NSCLC) comprises 85% of lung cancer diagnoses and is plagued by drug resistance. Thus, elucidating the underlying mechanisms of NSCLC is paramount to expand future treatment options. Paraoxonase 2 (PON2), an intracellular enzyme with arylesterase and lactonase functions, has well-established anti-atherosclerotic activity. Recent studies show PON2 is overexpressed in a variety of tumors and confers drug resistance, although these interactions have not been thoroughly examined in NSCLC. Thus, we sought to investigate the role of PON2 in cellular proliferation using PON2-knockout mice, primary mouse cells, and NSCLC cell lines. Using these approaches, we demonstrate that PON2 …


Glycine Receptor Expression Across Identified Retinal Ganglion Cell Types., Ian Scot Pyle May 2019

Glycine Receptor Expression Across Identified Retinal Ganglion Cell Types., Ian Scot Pyle

Electronic Theses and Dissertations

Retinal ganglion cells (RGCs) represent the culmination of all retinal signaling and their output forms the substrate for vision throughout the rest of the brain. About 40 different RGC types have been defined by differences in their visually evoked responses, morphology, and genetic makeup. These responses arise from interactions between inhibition and excitation throughout the retinal circuit (Franke et al., 2017; Masland, 2012; Sanes & Masland, 2015; Werblin, 2011). Unlike most other areas of the central nervous system (CNS), the retina utilizes both GABA and glycine inhibitory neurotransmitters to refine glutamatergic excitatory signals (Franke & Baden, 2017; Werblin, 2011; C. …


Development Of A Lectin-Fc Fusion Protein With Antiviral And Anti-Cancer Activity., Matthew William Dent May 2019

Development Of A Lectin-Fc Fusion Protein With Antiviral And Anti-Cancer Activity., Matthew William Dent

Electronic Theses and Dissertations

This thesis describes the development of a novel lectin-Fc fusion protein and its antiviral and anti-cancer activity. The molecule, Avaren-Fc (AvFc), is a fusion of a variant of the actinomycete lectin actinohivin (Avaren) and the Fc region of human IgG1, and is selective for the terminal α1,2-mannose residues found at the ends of high-mannose-type glycans that can be found on the surface of certain heavily glycosylated viruses and cancer cells. Here, AvFc was found to be able to neutralize simian immunodeficiency virus as well as Hepatitis C virus with nanomolar IC50 values. Furthermore, AvFc recognizes a number of cell …


Functional Consequence Of Psat1 Association On Pkm2'S Inherent Enzymatic Activity., Alexis Avidan Vega Dec 2018

Functional Consequence Of Psat1 Association On Pkm2'S Inherent Enzymatic Activity., Alexis Avidan Vega

Electronic Theses and Dissertations

Pyruvate kinase M2 (PKM2) is predominantly found in tumors, where it allows the cancer cell to adapt to metabolic conditions through allosteric regulation of its activity. We recently discovered that phosphoserine aminotransferase 1 (PSAT1) associates with and activates PKM2. Here, I sought to affirm PSAT1's ability to increase PKM2 activity through kinetic and association studies of wild-type or mutant PKM2 enzymes. I demonstrate that His-tagged WT and mutant PKM2 enzymes are active, exhibit different kinetics, yet cannot be activated by PSAT1. Comparison studies using untagged WT PKM2 suggest that inclusion of the His-tag disrupts PSAT1 association. In support, pull-down strategies …


Deciphering The Role Of Human Arylamine N-Acetyltransferase 1 (Nat1) In Breast Cancer Cell Metabolism Using A Systems Biology Approach., Samantha Marie Carlisle Aug 2018

Deciphering The Role Of Human Arylamine N-Acetyltransferase 1 (Nat1) In Breast Cancer Cell Metabolism Using A Systems Biology Approach., Samantha Marie Carlisle

Electronic Theses and Dissertations

Background: Human arylamine N-acetyltransferase 1 (NAT1) is a phase II xenobiotic metabolizing enzyme found in almost all tissues. NAT1 can additionally hydrolyze acetyl-coenzyme A (acetyl-CoA) in the absence of an arylamine substrate. NAT1 expression varies inter-individually and is elevated in several cancers including estrogen receptor positive (ER+) breast cancers. Additionally, multiple studies have shown the knockdown of NAT1, by both small molecule inhibition and siRNA methods, in breast cancer cells leads to decreased invasive ability and proliferation and decreased anchorage-independent colony formation. However, the exact mechanism by which NAT1 expression affects cancer risk and progression remains unclear. Additionally, consequences …


Bayesian Analytical Approaches For Metabolomics : A Novel Method For Molecular Structure-Informed Metabolite Interaction Modeling, A Novel Diagnostic Model For Differentiating Myocardial Infarction Type, And Approaches For Compound Identification Given Mass Spectrometry Data., Patrick J. Trainor Aug 2018

Bayesian Analytical Approaches For Metabolomics : A Novel Method For Molecular Structure-Informed Metabolite Interaction Modeling, A Novel Diagnostic Model For Differentiating Myocardial Infarction Type, And Approaches For Compound Identification Given Mass Spectrometry Data., Patrick J. Trainor

Electronic Theses and Dissertations

Metabolomics, the study of small molecules in biological systems, has enjoyed great success in enabling researchers to examine disease-associated metabolic dysregulation and has been utilized for the discovery biomarkers of disease and phenotypic states. In spite of recent technological advances in the analytical platforms utilized in metabolomics and the proliferation of tools for the analysis of metabolomics data, significant challenges in metabolomics data analyses remain. In this dissertation, we present three of these challenges and Bayesian methodological solutions for each. In the first part we develop a new methodology to serve a basis for making higher order inferences in metabolomics, …


The N-Terminal Methyltransferase Homologs Nrmt1 And Nrmt2 Exhibit Novel Regulation Of Activity Through Heterotrimer Formation., Jon David Faughn Aug 2018

The N-Terminal Methyltransferase Homologs Nrmt1 And Nrmt2 Exhibit Novel Regulation Of Activity Through Heterotrimer Formation., Jon David Faughn

Electronic Theses and Dissertations

Protein, DNA, and RNA methyltransferases have an ever-expanding list of novel substrates and catalytic activities. Even within families and between homologs, it is becoming clear the intricacies of methyltransferase specificity and regulation are far more diverse than originally thought. In addition to specific substrates and distinct methylation levels, methyltransferase activity can be altered through formation of complexes with close homologs. This work involves the N-terminal methyltransferase homologs NRMT1 and NRMT2. NRMT1 is a ubiquitously expressed distributive trimethylase. NRMT2 is a monomethylase expressed at low levels and in a tissue-specific manner. They are both nuclear methyltransferases with overlapping target consensus sequences …


Canonical Nuclear Factor-Κb Signaling In Satellite Stem Cell Homeostasis And Function., Alex R. Straughn Aug 2018

Canonical Nuclear Factor-Κb Signaling In Satellite Stem Cell Homeostasis And Function., Alex R. Straughn

Electronic Theses and Dissertations

Satellite cells are adult stem cells that are required for the regeneration of skeletal muscle following injury. However, the signaling mechanisms that regulate satellite stem cell homeostasis and function in adult animals remain less understood. Nuclear factor-kappa B (NF-kB) is a major nuclear transcription factor that regulates the gene expression of a plethora of molecules involved in cellular proliferation, differentiation, survival, and the inflammatory immune response. NF-kB can be activated through a canonical or non-canonical pathway. However, the role of canonical NF-kB signaling in the regulation of satellite stem cell function during skeletal muscle regeneration has not been yet investigated …


Type Ix Secretion System : Characterization Of An Effector Protein And An Insight Into The Role Of C-Terminal Domain Dimeration In Outer Membrane Translocation., Lahari Koneru Dec 2017

Type Ix Secretion System : Characterization Of An Effector Protein And An Insight Into The Role Of C-Terminal Domain Dimeration In Outer Membrane Translocation., Lahari Koneru

Electronic Theses and Dissertations

Porphyromonas gingivalis and Tannerella forsythia are two of the primary pathogens that are associated in the etiology and progression of chronic periodontitis. In T. forsythia, KLIKK proteases are the recently identified group of proteolytic enzymes that are secreted through Type IX secretion system (T9SS). Among, these KLIKK proteases a synergistic relationship was observed between karilysin and mirolysin in invading the host complement system for the survival of the bacteria. Since, karilysin has been already characterized, in this study we propose to study about mirolysin through structural, biochemical and biological characterization. The obtained results from the experiments has shown the …


The Dlk1-Meg3 Locus In Malignant Cells Of Proposed Primordial Germ Cell Origins., Zachariah Payne Sellers Aug 2017

The Dlk1-Meg3 Locus In Malignant Cells Of Proposed Primordial Germ Cell Origins., Zachariah Payne Sellers

Electronic Theses and Dissertations

Primordial germ cells (PGCs) are hypothesized to deposit hematopoietic stem cells (HSCs) along their migration route through the embryo during the early stages of embryogenesis. PGCs also undergo global chromatin remodeling, including the erasure and reestablishment of genomic imprints, during this migration. While PGCs do not spontaneously form teratomas, their malignant development into germ cell tumors (GCTs) in vivo is often accompanied by the retention of hypomethylation at the IGF2-H19 imprinting control differentially methylated region (DMR). Previous studies in bimaternal embryos determined that proper genomic imprinting at two paternally imprinted loci was necessary for their growth and development: Igf2-H19 and …


Tnf-Like Weak Inducer Of Apoptosis (Tweak) : Not So Weak After All., Joseph Dekward Mcmillan Iv Dec 2016

Tnf-Like Weak Inducer Of Apoptosis (Tweak) : Not So Weak After All., Joseph Dekward Mcmillan Iv

Electronic Theses and Dissertations

Background: Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) is a proinflammatory cytokine belonging to the TNF super family. TWEAK produces a variety of cellular responses through the binding to fibroblast growth factor inducible 14 (Fn14), a member of TNF receptor superfamily. Although Fn14 lacks a death domain, TWEAK has been found to induce apoptosis in some cell types by perturbing the activity of certain pathways such as TNF-receptor signaling. TWEAK is also known to regulate proliferation and differentiation of myogenic cells. We have previously reported that the TWEAK-Fn14 system causes skeletal muscle wasting both in vitro and in …


A Systems Biology Approach Identifies A Gene Regulatory Network In Parotid Acinar Cell Differentiation., Melissa Ann Metzler Aug 2016

A Systems Biology Approach Identifies A Gene Regulatory Network In Parotid Acinar Cell Differentiation., Melissa Ann Metzler

Electronic Theses and Dissertations

Objective: This project sought to understand the gene regulatory networks that drive parotid salivary gland acinar cells to terminally differentiate, and drive expression of terminal differentiation genes in dedifferentiated ParC5 cells. Methodology: Laser capture microdissection was used to isolate acinar cells at multiple time points during differentiation. This important step allowed us to measure gene expression in a single and important cell type. A systems biology approach was taken to measure global mRNA and microRNA expression across acinar cell terminal differentiation in the rat parotid salivary gland. In ParC5 cells, the ER stress activator tunicamycin was used to stimulate Xbp1 …


Role Of Microrna-21 In Atherogenesis., Rihab Hamed-Berair May 2016

Role Of Microrna-21 In Atherogenesis., Rihab Hamed-Berair

Electronic Theses and Dissertations

MicroRNA-21 (miR-21) is an evolutionarily conserved microRNA, abundant in most cardiovascular tissues. It has been implicated in the pathogenesis of several cardiovascular diseases including restenosis, myocardial infarction, and heart failure. However, little is known about the contribution of miR-21 in atherosclerosis. My data show that expression of miR-21 is increased by >1.5-fold in murine atherosclerotic lesions and by 1.5-2.0-fold in the macrophages of Western diet (WD)-fed LDLR-KO mice (for 12-20 weeks). In vitro, LDL, oxidized LDL, acetylated LDL and LPS induced miR-21 by 2-4-fold and down-regulated its target protein, PDCD4, in bone marrow-derived macrophages. Basally, macrophages isolated from miR-21-KO …


Modulation Of Cell Death Signaling And Cell Proliferation By The Interaction Of Homoserine Lactones And Paraoxonase 2., Aaron Mackallan Neely May 2016

Modulation Of Cell Death Signaling And Cell Proliferation By The Interaction Of Homoserine Lactones And Paraoxonase 2., Aaron Mackallan Neely

Electronic Theses and Dissertations

Pseudomonas aeruginosa produces N-(3-oxododecanoyl)-homoserine lactone (C12) as a quorum-sensing molecule that functions to facilitate bacteria-bacteria communication. C12 has also been reported to affect many aspects of human host cell physiology, including evoking cell death in various types of cells. However, the signaling pathway(s) leading to C12-triggerred cell death remains unclear. To clarify cell death signaling induced by C12, we examined mouse embryonic fibroblasts (MEFs) deficient in one or more caspases. Our data indicate that, unlike most apoptotic inducers, C12 evokes a novel form of apoptosis in cells, probably through the direct induction of mitochondrial membrane permeabilization. Previous studies indicate that …


Co-Treatment With Conjugated Linoleic Acid And Nitrite Modulates Mitochondrial Respiration And Electron Transport Chain Activity In Vivo And Attenuates Mitochondrial Dysfunction During Cardiac Injury., Patrick Van Hoose Dec 2015

Co-Treatment With Conjugated Linoleic Acid And Nitrite Modulates Mitochondrial Respiration And Electron Transport Chain Activity In Vivo And Attenuates Mitochondrial Dysfunction During Cardiac Injury., Patrick Van Hoose

Electronic Theses and Dissertations

Cardiovascular disease and subsequent complications, such as myocardial infarction (MI), is the leading cause of death within the United States. Clinical intervention to reduce cardiac damage following myocardial ischemia is limited. Polyunsaturated fatty acids have been linked to an overall beneficial effect on cardiovascular health and function. Conjugated linoleic acid (cLA) is an 18:2 unsaturated fatty acid found within the diet in ruminant meat and dairy products. The cis-9 trans-11 isomer of cLA is the most prominent isomer within the diet and cLA has been linked to favorable outcomes in numerous disease states. The mechanism mediating the effects of cLA …


Coordinate Regulation Of The Wnt And Hippo Pathways By The Novel Ras Effector Nore1a., Marvin Lee Schmidt Jr. Aug 2015

Coordinate Regulation Of The Wnt And Hippo Pathways By The Novel Ras Effector Nore1a., Marvin Lee Schmidt Jr.

Electronic Theses and Dissertations

Ras is the most frequently activated oncogene found in human cancer, but its mechanisms of action remain only partially understood. Ras activates multiple signaling pathways in order to promote transformation, but can also exhibit a potent ability to induce growth arrest and death. NORE1A (RASSF5) is a direct Ras effector that acts as a tumor suppressor promoting senescence and apoptosis. Its expression is frequently lost in human tumors and its mechanism of action remains unclear. Here I show that NORE1A forms a direct, Ras regulated, complex with β-TrCP, the substrate recognition component of the SCF-β-TrCP ubiquitin ligase complex. NORE1A also …


Role Of C-Kit In The Growth, Migration And Differentiation Of Human Cardiac Progenitor Cells., Bathri Narayan Vajravelu May 2015

Role Of C-Kit In The Growth, Migration And Differentiation Of Human Cardiac Progenitor Cells., Bathri Narayan Vajravelu

Electronic Theses and Dissertations

The belief that adult mammalian heart lacks regenerative potential was challenged by the identification of c-kit positive cardiac progenitor cells (CPCs) in the heart. A recent phase I clinical trial (SCIPIO), has shown that autologous c-kit positive CPCs improve cardiac function and quality of life when transplanted into ischemic heart disease patients. c-Kit is a type III receptor tyrosine kinase and a common stem cell antigen. Stem cell factor (SCF) is the only known ligand for c-kit. Although c-kit is extensively used as an invariable marker of resident CPCs and shown to be important in the context of different cell …


Biophysical And Computational Investigations Into G-Quadruplex Structural Polymorphism And Interaction With Small Molecules., Huy Tuan Le Aug 2014

Biophysical And Computational Investigations Into G-Quadruplex Structural Polymorphism And Interaction With Small Molecules., Huy Tuan Le

Electronic Theses and Dissertations

In the cell, guanine-rich nucleic acids can self-assemble into unique four stranded tertiary structures known as G-quadruplexes. G-quadruplex formation in the telomere leads inhibits telomerase, an enzyme activated in cancer cells to maintain the telomere and allowing for cancer cells to achieve immortality. G-quadruplex formation in the promoters and 5’-untranslated regions regulates the expression of many oncogenes. Furthermore, G-quadruplex formation during cellular replication promotes genomic instability, a characteristic which enables tumor development. Because of their implication in cancer, G-quadruplex structures have emerged as attractive drug targets for anti-tumor therapeutics. In the current dissertation work, we present three experimental approaches to …


Genetic And Mechanistic Analysis Of Rat Mammary Cancer Susceptibility., Jennifer Sanders Aug 2014

Genetic And Mechanistic Analysis Of Rat Mammary Cancer Susceptibility., Jennifer Sanders

Electronic Theses and Dissertations

Breast cancer is a complex disease, which is influenced by genetic, epigenetic and environmental components. Genetic susceptibility to breast cancer is made up of high, moderate and low penetrance alleles. High and moderate penetrance alleles are rare and constitute only a small percentage of the genetic susceptibility. Most variation in genetic susceptibility is controlled by low- penetrance, common polymorphisms. Comparative genetics uses model organisms to study human disease. Rat strains exhibit different susceptibility phenotypes to chemical induced carcinogenesis. The Wistar-Furth (WF) rat strain is susceptible to chemically induced mammary carcinogenesis, while the Wistar-Kyoto (WKy) and Copenhagen (COP) rat strains are …