Biochemistry, Biophysics, and Structural Biology Commons^™

Runx1 Loss Leads To An Epithelial To Mesenchymal Transition In Breast Cancer By Regulating Target Gene Expression., Dorcas Lohese

Graduate College Dissertations and Theses

Breast cancer is the second leading cause of cancer death among women in the United States. Due to the various advancements in treatment, the five-year survival rate is greater than 90% among women with non-metastatic breast cancer. However, among patients with metastatic breast cancer, the five-year survival rate quickly drops to 22%. Recognizing early signs of metastasis is essential for targeting cancer before it disseminates. The epithelial-to-mesenchymal transition (EMT) is hypothesized to be a vital process for large-scale cell movement by disrupting cell-cell adhesion, allowing metastatic breast cancer cells to become more migratory. The progression of breast cancer EMT involves …

Characterization Of Tau Disease-Associated Mutation, R5l, On Microtubule Bound Tau Behavoir And Function, Alisa Cario

Graduate College Dissertations and Theses

Proper coordination of the neuronal cytoskeleton is necessary for the health of the nervous system. Regulation of the microtubule cytoskeleton is achieved, in part, through microtubule associated proteins (MAPs). MAP-Tau, an intrinsically disordered protein highly expressed in axons, functions in signaling cascades, regulation of motor motility, as well as the direct regulation of microtubule dynamics. Tau misregulation and mutations are linked to a class of neurodegenerative diseases called Tauopathies, characterized by the aggregation of Tau. These include progressive supranuclear palsy (PSP), Pick's disease, and Alzheimer's disease. Many of the disease-associated mutations in Tau are found in the microtubule-binding domain, in …

Exploring The Mechanisms Of Pkg1-Α Activation By Synthetic Peptides, Connor Cronin

Graduate College Dissertations and Theses

Cyclic GMP-dependent protein kinases (PKG’s) are essential signaling macromolecules which play a pivotal role in vascular physiology and smooth muscle tone regulation. As principle downstream effectors of the secondary messenger cyclic 3’, 5’-guanosine-monophosphate (cGMP), PKG isoforms are expressed in high levels in all types of smooth muscle cells. The broad range of cellular functions effected by PKG include platelet aggregation, hypertrophy, apoptosis, neuronal plasticity, gene expression, differentiation, vasorelaxation, vascular remodeling, calcium homeostasis, and cardiac function. Recently, a newly characterized helical switch domain within the alpha isoform of PKG (PKG1-α) has led to the development of S1.1, a novel cGMP-independent peptide …

Characterization And Manipulation Of O-Glcnacylation In Granulosa Cells Of Bovine Ovarian Antral Follicles, Abigail Marie Maucieri

Graduate College Dissertations and Theses

Glucose is widely recognized as the preferred energy substrate for metabolism by granulosa cells (GCs). Yet in most cells, 2-5% of glucose is shunted through the hexosamine biosynthesis pathway (HBP) for O-linked N-acetylglucosaminylation (O-GlcNAcylation). O-GlcNAcylation is an evolutionarily-conserved, post-translational process that modifies serine and threonine residues on a variety of proteins. O-GlcNAcylation is also considered a nutrient sensor that can regulate cellular processes such as metabolism, signal transduction, and proliferation. In this respect, O-GlcNAcylation may be similar to, and possibly mediate, AMP-activated protein kinase (AMPK) signaling and its nutrient-sensing actions. However, the occurrence of O-GlcNAcylation and its relative importance to …

The Impact Of Nitric Oxide On Dendritic Cell Metabolism, Julia Priscilla Snyder

Graduate College Dissertations and Theses

Dendritic cells (DCs) are sentinel immune cells capable of directly sensing and responding to pathogens. Upon pathogen recognition, DCs undergo a process of activation that allows them to participate in the proinflammatory response at the site of infection and to initiate the adaptive immune response through antigen presentation to T cells. Because activated DCs serve as the critical link between innate and adaptive immunity, modulating DC activation could be a powerful tool in various clinical contexts such as vaccine design. DC activation is accompanied by widespread changes in metabolism including the rapid upregulation of glycolysis, which is sustained in DCs …

Thyroid Hormone Receptor Beta Inhibits Pi3k Signaling And Glycogen Metabolism In Anaplastic Thyroid Cancer, Cole Davidson

Graduate College Dissertations and Theses

Thyroid cancer is the most common endocrine malignancy, and the global incidence has increased rapidly over the past few decades. While differentiated thyroid cancers often respond to standard therapies, there are no durable long-term treatment options for anaplastic thyroid cancer (ATC). The limited treatment options highlight a need for a deeper understanding of the molecular signaling in these aggressive tumors for development of more effective therapies.Non-steroidal nuclear receptors, such as thyroid hormone receptors (TRs), are an emerging class of therapeutic targets and tumor suppressors in thyroid and other cancers.Loss of expression of the tumor suppressor thyroid hormone receptor beta (TRβ) …

Characterizing The Interaction Of Polymerase Θ Helicase-Like Domain With Dna, Scott Vanson

Graduate College Dissertations and Theses

DNA damaging events occur every day in every cell of all living organisms andsome may result in double-stranded breaks (DSB). Human DNA polymerase θ (Pol θ) is a large, 290 kDa DNA repair enzyme and is the only known protein to contain both a polymerase domain and a helicase-like domain (HLD) as one molecule. Pol θ is the key mediator of the error-prone DSB repair pathway, Theta-mediated End Joining. This enzyme has been identified as a potential therapeutic target as it may be conferring a survival advantage to subsets of homologous recombination (HR)-deficient cancers, which display elevated expression levels of …

Much Needed Studies Of The Three Players Of Chagas Disease In Central America: Vertebrate Blood Meal Sources And Ecohealth, A New Vector Species Description, And Key Phylogenetic Analysis Of The Trypanosome Parasite., Raquel Asuncion Lima Cordon

Graduate College Dissertations and Theses

The protozoan parasite Trypanosoma cruzi (Trypanosomatida: Trypanosomatidae) is the etiological agent of Chagas disease, reported by the World Health Organization (WHO) as responsible for over 10,000 deaths in 2015. Chagas disease is considered a Neglected Tropical Disease by the WHO, this designation highlights the challenges to overcoming the disease as it afflicts the most vulnerable populations, mainly the rural poor in Latin America. Understanding T. cruzi transmission dynamics is particularly difficult because it can be vectored by over 150 species of Triatominae insects, and all mammal species are potential hosts. Thus, results from one locale may not be generalizable to …

Transcriptional Programming By Thyroid Hormone Receptor Beta Maintains Normal Cell Identity And Suppresses Tumor Growth, Noelle Elizabeth Gillis

Graduate College Dissertations and Theses

The overall incidence of thyroid cancer has more than tripled over the past several decades, as has aggressive disease and mortality. The direct relationship between thyroid disease, thyroid hormone levels, and development of thyroid cancer is incomplete. Recent meta-analyses have indicated a higher risk of thyroid cancer for patients with thyroid diseases that reflect an altered thyroid-pituitary signaling axis, which can have profound impacts on the physiology of the thyroid gland. These largely unanswered questions regarding altered thyroid hormone signaling and its consequences for thyroid tumor growth present a significant clinical challenge. This dilemma may come from a lack of …

Structural Characterization Of The Novel Flightin Domain Wyr And Its Defining Role In The Thick Filament Structure And Mechanics, Lynda Menard

Graduate College Dissertations and Theses

The evolutionary success of Insecta has been attributed largely to the development of efficient means of motility: flight powered by muscle architecture harboring a largely conserved yet tunable system of power relay. The indirect flight muscle (IFM) of Drosophila melanogaster is a well-studied model for dissection of the structural and mechanical means by which muscle operates and evolves. Striated muscle, conserved throughout Animalia, is demarcated by an ordered array of thick- and thin-filaments prominently composed of the proteins myosin and actin. Flightin (fln) is a myosin binding thick filament protein essential for IFM stability, structure and function. The manner by …

Lcms-Based Analysis Explains The Basis Of Oxidative Resistance In Selenium-Containing Thioredoxin Reductase, Daniel Haupt

Graduate College Dissertations and Theses

Selenocysteine (Sec) is referred to as the 21st proteogenic amino acid and is found in place of the redox-sensitive amino acid cysteine (Cys) in a small number of proteins. Sec and Cys carry out similar chemistry and are structural isomers save for a single atom difference; the former contains selenium (Se), while the latter contains sulfur (S) in the identical position. Sec poses a high bioenergetic cost for its synthesis and subsequent incorporation into protein not shared by Cys. Since Sec’s discovery in 1976, scientists have debated why certain proteins express Sec while others express Cys. In recent years, it …

Designer Biologics Composed Of Hepatocyte Growth Factor, Fibroblast Growth Factor 2 And Immunoglobulin G For Treatment Of Acute Myocardial Infarction, Benjamin Liebman

Graduate College Dissertations and Theses

ABSTRACT Coronary artery disease leading to myocardial infarction (a.k.a. MI, heart attack) is one of the leading causes of death globally. Each year an estimated 605,000 Americans suffer a heart attack, which equates to one MI every 40 seconds. As such, MI represents one of the largest health burdens to society. The current standard of care is revascularization therapy achieved by fibrinolytics and Percutaneous Coronary Intervention (PCI); both of which re-open occluded proximal arteries to restore blood flow to the affected areas. Despite revascularization therapy, 30-50% of patients exhibit a form of reperfusion injury termed “no/low-reflow” in which the blood …

The Maintenance Of Genomic Stability: Impacts Of The Loss Of Kif18a, Leslie Anne Sepaniac

Graduate College Dissertations and Theses

Regulated and repeated cell division is necessary for the development, growth, and reproduction of multicellular organisms. A central purpose of mitosis is to faithfully pass hereditary information from one cell onto two genetically identical daughter cells, thus maintaining genomic stability. Cells employ several mechanisms for maintaining genomic stability, including well-characterized cell cycle checkpoints. However, chromosome segregation errors can occur in spite of these regulatory mechanisms. Such errors can result in an improper number of chromosomes being distributed to daughter cells – termed aneuploidy – or improper localization of chromosomes into separate satellite nuclei – termed micronuclei. What, if any, additional …

Sarracenia Purpurea As A Model System For Aquatic Ecosystem State Changes And Their Impact On Bacterial Communities, Amanda Claire Northrop

Graduate College Dissertations and Theses

Aquatic ecosystems can undergo abrupt and long-lasting transitions from one state to another, often with negative ecological and economic consequences. With anthropogenic enrichment, aquatic ecosystems such as lakes and ponds may shift rapidly from an oligotrophic, clear water state to a eutrophic, turbid state. These shifts, or state changes, generally occur due to a phenomenon called hysteresis in which the relationship between a driving variable and ecosystem variable depend on the current state of the ecosystem. Such dynamics often make recovery difficult or impossible. Though state changes in aquatic ecosystems have been studied extensively since the 1970s, there have been …

Glutathionylation/Glutaredoxin Axis And The Regulation Of Epithelial Cell Plasticity And Fibroblast Activation In Airway Fibrosis, Shi Biao Chia

Graduate College Dissertations and Theses

Asthma is a complex lung disorder that affects more than 200 million people across the globe. About 10% of asthmatics have severe disease accompanied by structural airway remodeling, including subepithelial fibrosis, airway smooth muscle cell hyperplasia, goblet metaplasia, and increased vascularization. Oxidative stress has been well-linked to asthma pathogenesis; however, the precise redox mechanisms governing the pathological states are slowly being teased apart in the recent years. Protein S-glutathionylation (PSSG) is a posttranslational modification where a three amino acid-peptide, glutathione, forms a disulfide bond with reactive cysteines of a protein thereby potentially changing the protein’s biological functions. Glutaredoxins are members …

Anti-Tumor Signaling Of Thyroid Hormone Receptor Beta In Breast And Thyroid Cancer Cells, Eric Bolf

Graduate College Dissertations and Theses

Dysregulation of the tumor suppressor thyroid hormone receptor beta (TRβ) is a frequent event in a number of solid tumors. As a nuclear hormone receptor, the primary function of TRβ is to regulate transcriptional activity in a ligand-dependent manner. However, TRβ activity is not well-defined and the pathways it regulates are not yet fully delineated. The two cancer types where TRβ is best studied are thyroid cancer and breast cancer. Interestingly, thyroid cancer is a risk factor for breast cancer and breast cancer is a risk factor for thyroid cancer, suggestive of an etiological link. Determining the molecular mechanisms of …

Novel Pausing Behavior Of The Kinesin-3 Family Member Kif1a Is Regulated By Tau, Dominique V. Lessard

Graduate College Dissertations and Theses

The unique relationship between neuronal structure and function is paramount for the complexity of the human nervous system. This relationship allows neurons to receive, process, and transmit information through many inter- and intracellular mechanisms. Axonal transport is an essential intracellular mechanism for neuronal health and viability. This process involves the transport of cellular cargo in the anterograde and retrograde direction along the axon, relaying materials between the soma and axon terminals, respectively. The necessity of an expedited form of transport becomes clear when one considers the magnitude of distance cargo must travel; in some cases, the axon can be up …

Tsrna Involvement In Promoting Breast Cancer Phenotypes, Stephanie Scalia

Graduate College Dissertations and Theses

The overall 5-year survival rate for woman diagnosed with breast cancer has increased significantly over the last 20 years. However, prognosis for women with stage IV, metastatic disease remains very poor. Women diagnosed with stage 0-III breast cancer have above an 85% chance of survival over a 5-year period while women diagnosed with stage IV breast cancer have a 5-year survival of less than 30%. A better understanding of the molecular mechanisms driving aggressive breast cancer is essential for the potential discovery of more targeted therapies to increase the survival rates for women diagnosed with stage IV breast cancer.

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Investigating The Runx1-Cbfβ Transcription Factor Complex As A Mitotic Gene Bookmark To Maintain The Normal Mammary Epithelial Phenotype, Eliana Moskovitz

Graduate College Dissertations and Theses

Disruption of normal mammary epithelial cell homeostasis through acquisition of

deleterious somatic and/or germline mutations leads to breast cancer development. Breast

cancer is the most commonly diagnosed cancer among women worldwide, and is

associated with the second highest amount of cancer-related deaths. Breast cancer

mortality rates are decreasing, likely through increased methods of detection and

development of targeted therapies. However, due to the complexity and heterogeneity of

the disease, the incidence rate remains high and the molecular events that lead to breast

cancer initiation and progression are poorly understood.

The epithelial-to-mesenchymal transition (EMT) is an essential molecular process

involved in …

Implications Of The Calm-Af10 Oncogenic Fusion Protein On Wnt Signaling In Leukemia, Jamie Lucille Deutsch

Graduate College Dissertations and Theses

Hematopoiesis is the complex differentiation process involving the formation of all blood cells from a common progenitor; the hematopoietic stem cell. Errors in this process can lead to acute leukemia, or a rapid accumulation of immature blood cells which hinders proper immune function. While survival rates of this devastating disease have increased dramatically over the last several decades, certain cytogenetic abnormalities remain risk factors for treatment resistance and relapse. One of these abnormalities is a chromosomal translocation involving the transcription factor, AF10

Mix-Lineage Leukemia, Translocated to, 10 (MLLT 10, referred to as AF10) is involved in several oncogenic translocations involved …

The Utilization Of Host-Derived Compounds By Gram-Negative Bacteria, Lauren Alexandra Hinkel

Graduate College Dissertations and Theses

The increase in multidrug resistance (MDR) among bacterial pathogens is an ongoing threat to public health, with the CDC estimating more than 2.8 million MDR infections in the United States each year, and greater than 35,000 deaths annually. Gram-negative bacteria possess intrinsic mechanisms to resist available therapeutics and are frequently responsible for difficult-to-treat nosocomial, blood stream, and soft tissue infections. In addition to biophysical and genetic MDR mechanisms, Gram negatives are metabolically versatile, enabling them to utilize host-derived nutrients to promote proliferation and colonization within the host. The metabolic versatility of Gram-negative bacteria is due, in part, to the transcription …

Investigations Into Signaling Mechanisms Of The Dcbld Receptor Family, Anna Schmoker

Graduate College Dissertations and Theses

Cells communicate to drive all biological processes during organismal development, homeostasis, and disease. Communication, or signaling, is carried out through an orchestration of complex sequential molecular interactions. A signal is typically initiated by an extracellular cue binding to a receptor on the cell membrane, which induces an intracellular response, resulting ultimately in cellular phenotypes such as growth, proliferation, migration, apoptosis or survival. Adaptor proteins are critical to signal transduction, as they facilitate the formation of protein complexes that transduce signals. CT10 regulator of kinase (CRK) and CRK-like (CRKL) form a family of adaptors that facilitate complex formation during developmental signaling, …

Exosomes And Their Role In Asbestos Exposure And Mesothelioma, Phillip Blake Munson

Graduate College Dissertations and Theses

Malignant mesothelioma (MM) is a locally invasive and highly aggressive cancer arising on the mesothelial surface of organ cavities (mainly pleural) as a direct result of asbestos exposure. The latency period of MM is long (20-50yrs) after initial asbestos exposure, and the prognostic outcomes are dismal with median life expectancy of 6-12 months post-diagnosis. There are no useful biomarkers for early MM diagnosis, no successful therapeutic interventions. These vast voids of knowledge led to our hypotheses that secreted vesicles, termed exosomes, play an important role in MM development and tumorigenic properties. Exosomes are nano-sized particles secreted from all cell types …

Effects Of Tumor-Related Factors And Chemotherapy On Skeletal Muscle And The Protective Effects Of Exercise, Blas Anselmo Guigni

Graduate College Dissertations and Theses

Cancer patients often experience cachexia, a form of weight loss consisting mostly of skeletal muscle wasting. Muscle wasting leads to physical disability, poor quality of life, reduced tolerance to treatments and shorter survival. Although the causes of cancer-related muscle atrophy have been studied for decades, the exact mechanisms through which cancer and its treatments promote muscle wasting have yet to be defined.

The overall aim of this dissertation is to examine the mediators of muscle wasting in cancer patients during their treatment and examine the modulatory role of exercise to maintain muscle size and function. To address these aims, we …

Endotoxin Increases Oxidative Stress And Oxygen Tension While Reducing Milk Protein Gene Expression In The Mammary Gland, Alexander Jonathan Spitzer

Graduate College Dissertations and Theses

Mastitis, the inflammation of the mammary gland by bacterial infection, is one of the costliest diseases to the dairy industry primarily due to a loss in milk production. The aim of this study was to investigate the mechanisms underlying reduced milk production during mastitis. We hypothesized that bacterial endotoxin induces cell apoptosis, oxidative stress and increases hypoxia while inhibiting milk gene expression in the mammary gland. To test this hypothesis, mice were bred to pregnancy, and 3 days post-partum the left and right sides of the 4th pair of mammary glands were alternately injected with either the endotoxin liposaccharide (LPS, …

Caught In Motion: Structural Studies Of Nucleic Acid Repair Enzymes, Brittany Carroll

Graduate College Dissertations and Theses

Cells synthesize proteins, the molecular instruments of all cellular processes, via

intermediate biomolecules that are susceptible to damage at every step. Known as the

central dogma of molecular biology, genes encoded in deoxyribonucleic acid (DNA) are

transcribed, spliced, and matured into messenger ribonucleic acid (mRNA). These

nucleic acids direct protein synthesis by the pairing of nucleotide triplets with transfer

RNA (tRNA). tRNAs concomitantly decode the so-called codon, as they escort the

correct amino acid to the ribosome for extension of the nascent polypeptide chain.

Damage to any of these intermediate biomolecules can be highly damaging to protein

synthesis, leading to …

Characterization Of Epigenetic Plasticity And Chromatin Dynamics In Cancer Cell Models, Diana Lea Gerrard

Graduate College Dissertations and Theses

Cancer progression is driven by cumulative changes that promote and maintain the malignant phenotype. Epigenetic alterations are central to malignant transformation and to the development of therapy resistance. Changes in DNA methylation, histone acetylation and methylation, noncoding RNA expression and higher-order chromatin structures are epigenetic features of cancer, which are independent of changes in the DNA sequence. Despite the knowledge that these epigenetic alterations disrupt essential pathways that protect cells from uncontrolled growth, how these modifications collectively coordinate cancer gene expression programs remains poorly understood. In this dissertation, I utilize molecular and informatic approaches to define and characterize the genome-wide …

Maintenance Of Mammary Epithelial Phenotype By Transcription Factor Runx1 Through Mitotic Gene Bookmarking, Joshua Rose

Graduate College Dissertations and Theses

Breast cancer arises from a series of acquired mutations that disrupt normal mammary epithelial homeostasis and create multi-potent cancer stem cells that can differentiate into clinically distinct breast cancer subtypes. Despite improved therapies and advances in early detection, breast cancer remains the leading diagnosed cancer in women.

A predominant mechanism initiating invasion and migration for a variety of cancers including breast, is epithelial-to-mesenchymal transition (EMT). EMT— a trans-differentiation process through which mammary epithelial cells acquire a more aggressive mesenchymal phenotype—is a regulated process during early mammary gland development and involves many transcription factors involved in cell lineage commitment, proliferation, and …

Studies On The Molecular Mechanism Of S-Tide Mediated Activation Of Pkg-Iα, Joseph William Charles

Graduate College Dissertations and Theses

cGMP-dependent protein kinases (PKG) are key players in intracellular second messenger signaling within many cellular systems throughout the body. Most notably PKG is known for its role in smooth muscle relaxation (Pfeiffer et.al, 1999). The Iα PKG isozyme has been identified as the primary effector of the nitric oxide pathway (and serves to be a novel drug target). To date the overall knowledge of structure and function of PKG is lacking in terms of the mechanisms of activation and the structural orientations that coordinate them. Recently, our laboratory has solved the crystal structure of the regulatory domain of PKG Iα, …

Biochemical Characterization Of The Dimerization Domain Of Purine-Rich Element Binding Protein B: An Essential Subdomain Mediating The Repression Of Smooth Muscle Alpha Actin Gene Expression, Lauren Ferris

Graduate College Dissertations and Theses

A number of physiologic processes require the expression of smooth muscle alpha actin (SMαA) to mediate cellular contraction. Stable expression of SMαA in differentiated vascular smooth muscle cells is associated with a contractile phenotype that is essential for regulation of blood flow and pressure. The transient expression of SMαA in myofibroblasts during wound repair facilitates wound closure. Hence, it is no surprise that dysregulation of SMαA gene expression in both cell types can have pathological consequences. Indeed, aberrant SMαA gene regulation has been implicated in diseases such as atherosclerosis and fibrosis. Therefore, a better understanding of the molecular mechanisms that …