Life Sciences Commons^™

Investigating The Impact Of Intragenic Dna Methylation On Gene Expression, And The Clinical Implications On Tumor Cells And Associated Stroma, Michael Mcguire

Dissertations and Theses (Open Access)

Investigations into the function of non-promoter DNA methylation have yielded new insights into epigenetic regulation of gene expression. Previous studies have highlighted the importance of distinguishing between DNA methylation in discrete functional regions; however, integrated non-promoter DNA methylation and gene expression analyses across a wide number of tumor types and corresponding normal tissues have not been performed. Through integrated analysis of gene expression and DNA methylation profiles, we uncovered an enrichment of DNA methylation sites within the gene body and 3’UTR in which DNA methylation is strongly positively correlated with gene expression. We examined 32 tumor types and identified 57 …

Nanoscale Organization Of The Small Gtpase Rac1, Kelsey Maxwell

Dissertations and Theses (Open Access)

Rac1 is a small, guanine-nucleotide binding protein that cycles between an inactive GDP-bound and active GTP-bound state to regulate actin-mediated motility, migration, and adhesion. Plasma membrane (PM) localization is essential for its biological activity. Rac1 PM targeting is directed by a C-terminal membrane anchor that encompasses a geranylgeranyl-cysteine-methyl-ester, palmitoyl, and a polybasic domain (PBD) of contiguous lysine and arginine residues. Using high-resolution imaging combined with spatial mapping analysis, I found that Rac1 forms nanoclusters on the PM. Cycling between the GTP- and GDP-bound states, Rac1 forms nanoclusters that are non-overlapping, consequently undergoing guanine nucleotide-dependent spatial segregation. I further found that …

Examining The Relationship Between Genetic Counselors’ Implicit Attitudes To Ward Disability And Their Practice Methods, Helen W. Gould

Dissertations and Theses (Open Access)

Genetic counselors serve as a link between the medical community and the disability community as they are regularly the first exposure families have following a new diagnosis in a pregnancy, infant or child. This role requires genetic counselors to be responsible and compassionate when approaching conversations about disability. With a lack of research on how the specific attitudes of genetic counselors toward disability impact clinical practice, we aimed to understand these attitudes, what factors affect implicit attitudes toward disability, and how these attitudes affect counseling. Case scenarios involving disability were used to examine different counseling content preferences within a genetic …

Genetic Testing Practices Of Genetic Counselors, Geneticists, And Pediatric Neurologists With Regard To Childhood-Onset Neurogenetic Conditions, Sara Wofford

Dissertations and Theses (Open Access)

Identifying genetic diagnoses for neurological conditions with a considerable hereditary component, such as autism spectrum disorder (ASD), intellectual disability, and epilepsy, is critical to providing proper medical management for these patients and their families. However, many patients with these conditions are not tested appropriately or receive no genetic testing at all. The current study was designed to characterize the genetic testing practices of the providers most likely to evaluate or order genetic testing for these patients: pediatric neurologists, geneticists, and genetic counselors. The study noted significant variance between the testing strategies selected by pediatric neurologists compared to those of geneticists …

Outcomes Of Genetic Testing In A Genitourinary Genetics Clinic, Annelise Pace

Dissertations and Theses (Open Access)

Several known hereditary cancer syndromes confer an increased risk for genitourinary (GU)related malignancies. Various guidelines indicate when to refer patients to genetic counseling for GU-related hereditary cancer syndromes but there is limited research on the clinical picture of these patients, including their cancerous and non-cancerous features, the genetic testing strategy for this population, and the probability of having a positive germline mutation if testing is performed. The purpose of this study is to determine the most common indications for ordering genetic testing in a GU Genetics Clinic and evaluate whether there is a relationship between the indication for genetic testing …

Computational Insights Into The Generation Of Chromosomal Copy Number Changes, Yihua Liu

Dissertations and Theses (Open Access)

Deviations from a diploid configuration of the human genome, spanning single genes or entire chromosomes, can have wide-ranging impacts on the variation of human phenotypes, including Mendelian and complex forms of diseases. These chromosomal alterations — such as duplications, deletions or copy-neutral loss-of-heterozygosity — are thus important forms of genetic variation for phenotyping populations of individuals as well as populations of cells. Indeed, copy number variants (CNVs) serve as hallmarks of critical changes in the development of particular diseases such as cancer and thus may be used as biomarkers. These CNVs may be either inherited (transmitted by germ cells, originating …

Trim24 In Normal & Malignant Hematopoiesis, Justin Shaw

Dissertations and Theses (Open Access)

Treatment for acute myeloid leukemia (AML) has changed little in the past four decades. For the majority of AML patients, current treatment options include chemotherapy and allogeneic stem cell transplants, which also involves high-dose chemotherapy or radiation treatment. These options have little success in the long-run, as only an estimated 26% of patients survive five years post-diagnosis. In efforts to address this low survival rate, interest has increased for targeting epigenetic pathways in AML. This focus stems from the discovery that AML is frequently driven by blockades on hematopoietic stem cell differentiation, which involves a series of coordinated epigenetic changes. …

Tumor Immunotherapy: Mechanisms Of Acquired Resistance And Characterization Of Immune Related To Xicities, Ashvin Jaiswal

Dissertations and Theses (Open Access)

Tumor immunotherapy has shown very promising clinical benefit across an array of cancers; however, two major challenges remain unresolved in the field. First, many patients do not respond to therapy at all or relapse after a period of remission. Second, there are often dose-limiting immune related adverse effects associated with immunomodulation.

In order to understand the mechanisms employed by tumors to evade immunotherapeutic responses, we established a murine model of melanoma designed to elucidate the molecular mechanisms underlying immunotherapy resistance. Through multiple in vivo passages, we selected a B16 melanoma tumor line that evolved complete resistance to combination blockade of …

Phosphorylation Impairs Dicer1 Function To Accelerate Aging And Tumorigenesis In Vivo, Neeraj Aryal

Dissertations and Theses (Open Access)

Altered DICER1 protein levels are associated with developmental disorders, infertility, macular degenerative blindness, aging, and cancer in humans. Recently, post-translational regulation of Dicer1 via phosphorylation has been described in C. elegans. Oscillation of Dicer1 phosphorylation to regulate its activity is essential for germ cell development and embryogenesis in worms. These observations led us to posit that Dicer1 protein levels and activity are under tight regulation for normal mammalian homeostasis. To test whether phosphorylation of Dicer1 regulates its activity in mammals, I generated phospho-mimetic knock-in mouse models by replacing Serines 1712 and 1836 with Aspartic acids individually or together (dual …

Sphingosine Kinase 1 Regulates Fascin Expression To Promote Metastasis In Triple Negative Breast Cancer, Sunil Acharya

Dissertations and Theses (Open Access)

Distant metastasis is the primary cause of breast cancer–related mortality. To date, effective therapeutic drugs that target metastasis are still lacking. Triple negative breast cancer (TNBC) occurs in high frequency in young women and are more likely to recur and metastasize than are other breast cancer subtypes. Also, TNBC patients cannot benefit from currently available hormonal or targeted therapies, as they lack estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2. Thus, understanding the signaling pathways that promote TNBC metastasis and developing novel therapeutic approaches to target them are critical, in order to prolong the survival and improve …

Deciphering The Roles Of Δnp63 In Regulating Epithelial To Mesenchymal Transition, Cancer Progression And Metastasis, Ngoc Bui

Dissertations and Theses (Open Access)

p63 is a member of the p53 family, a well-known tumor suppressor which is considered the guardian of the genome. The TP63 gene encodes multiple isoforms that can be categorized into two main isoforms, TAp63 and ΔNp63, which are expressed in different cellular compartments and have distinct functions in many biological processes. While the Flores laboratory identified TAp63 as a tumor and metastasis suppressor, the precise roles of ΔNp63 isoforms in tumorigenesis and metastasis remain elusive. ΔNp63 is the predominant p63 isoform expressed in the epidermis and plays essential roles in regulating epidermal development and homeostasis. Utilizing a ΔNp63-conditional …

Trim24 As An Oncogene In The Mammary Gland, Aundrietta Duncan

Dissertations and Theses (Open Access)

Despite the many advances made in breast cancer research and treatments, breast cancer remains one of the deadliest diseases plaguing women worldwide. While many findings on genetic mutations and their role in predisposing people to breast cancer have been uncovered, we are just beginning to understand the extent to which epigenetic regulators promote tumorigenic phenotypes, metastasis, and chemotherapeutic resistance. Moreover, new experimental tools offer the ability to address questions we were previously unable to assess. My project takes advantage of a new mouse model to understand the role of a proto-oncogenic, transcriptional co-regulator, TRIM24, in mammary gland development and disease. …

Biological Clocks, Inflammation, And Multiorgan Damage In Sickle Cell Disease, Morayo Adebiyi

Dissertations and Theses (Open Access)

Sickle cell disease (SCD) is a dangerous condition caused by a genetic mutation on the human beta-globin gene that contributes to erythrocyte sickling, the hallmark of the disease. Previous metabolomics studies have confirmed that elevated sphingosine kinase 1 (SphK1) mediates sphingosine-1-phosphate (S1P) production to promote erythrocyte sickling. S1P signals via five S1P receptors (S1PR) regulates several pathophysiological functions.

In the first chapter of this dissertation, I explored the role of S1PRs in SCD by utilizing pharmacologic and genetic tools. To determine the role of S1P-S1PRs signaling in SCD, I treated humanized Berkeley sickle mice (Berkeley HBS mice), with FTY720, a …

Identification And Utility Of Dna In Exosomes, Paul Kurywchak

Dissertations and Theses (Open Access)

Cancer-associated mortality has been declining for two decades but remains a significant public health problem, especially when patients initially present with advanced disease. Early detection methods have improved survival rates but remain unavailable for a majority of cancers due to a lack of sensitive biomarkers or numerous limitations associated with current diagnosis strategies. Approaches to develop “liquid biopsies” by detecting tumor cells or DNA in the blood have led to several breakthroughs and create the potential for non-invasive, routine assessment of diseases status. However, these biomarkers are rare and currently difficult to isolate, especially in the early stages of disease. …

The Regulation Of Dna Methylation In Mammalian Development And Cancer, Nicolas Veland

Dissertations and Theses (Open Access)

DNA methylation is an essential epigenetic modification in mammals, as it plays important regulatory roles in multiple biological processes, such as gene transcription, maintenance of chromosomal structure and genomic stability, genomic imprinting, retrotransposon silencing, and X-chromosome inactivation. Dysregulation of DNA methylation is associated with various human diseases. For example, cancer cells usually show global hypomethylation and regional hypermenthylation, which have been implicated in genomic instability and tumor suppressor silencing, respectively. Although great progress has been made in elucidating the biological functions of DNA methylation over the last several decades, how DNA methylation patterns and levels are regulated and dysregulated is …

Discovery And Effects Of Pharmacological Inhibition Of The E3 Ligase Skp2 By Small Molecule Protein-Protein Interaction Disruptors, John K. Morrow

Dissertations and Theses (Open Access)

Skp2 (S-phase kinase-associated protein 2), one component of the SCF E3 ubiquitin ligase complex, directly interacts with Skp1 and indirectly associates with Cullin1 and Rbx1 to bridge the E2 conjugating enzyme with its protein substrate to execute its E3 ligase activity. Skp2 is an Fbox protein (due to it containing an Fbox domain) and it is the rate-limiting component of the SCF complex. Skp2 targets several cell-cycle regulatory proteins for ubiquitination and degradation; most notable and significant for cancer are the cyclin-dependent kinase inhibitor, p27. Skp2 is an oncogene and studies have shown that over-expression of Skp2 leads to increased …

Using The Literature To Identify Confounders, Scott Malec

Dissertations and Theses (Open Access)

Prior work in causal modeling has focused primarily on learning graph structures and parameters to model data generating processes from observational or experimental data, while the focus of the literature-based discovery paradigm was to identify novel therapeutic hypotheses in publicly available knowledge. The critical contribution of this dissertation is to refashion the literature-based discovery paradigm as a means to populate causal models with relevant covariates to abet causal inference. In particular, this dissertation describes a generalizable framework for mapping from causal propositions in the literature to subgraphs populated by instantiated variables that reflect observational data. The observational data are those …

A Frame-Based Nlp System For Cancer-Related Information Extraction, Yuqi Si, Kirk Roberts

Faculty, Staff and Student Publications

We propose a frame-based natural language processing (NLP) method that extracts cancer-related information from clinical narratives. We focus on three frames: cancer diagnosis, cancer therapeutic procedure, and tumor description. We utilize a deep learning-based approach, bidirectional Long Short-term Memory (LSTM) Conditional Random Field (CRF), which uses both character and word embeddings. The system consists of two constituent sequence classifiers: a frame identification (lexical unit) classifier and a frame element classifier. The classifier achieves an F

A License To Kill: Understanding Natural Killer Cell Licensing To Fight Cancer, Jolie Schafer

Dissertations and Theses (Open Access)

Natural killer (NK) cell education is an essential developmental process for NK cell effector function, that renders some NK cells “licensed” and others “unlicensed” (with heightened or lowered effector function potential, respectively) against tumor and targets lacking self-molecules. However, the underlying mechanisms responsible for the heightened effector responses of licensed cells remain unknown. Using NK cells derived from humans and expanded ex vivo we performed high-throughput protein expression analysis, and identified multiple proteins that are differentially regulated in licensed and unlicensed human NK cells before and after inhibition by killer-cell immunoglobulin-like receptors (KIRs) and activation by the NKp46 natural cytotoxicity …

Evaluating The Therapeutic Efficacy Of Restoring Wild-Type P53 Activity In P53-Mutant Tumors, Connie A. Larsson

Dissertations and Theses (Open Access)

The p53 transcription factor is the most frequently altered in human cancers usually via missense mutations that undermine its transcriptional activity. Clinically, TP53 mutations have been shown to be remarkably predictive of refractoriness to treatment, resulting in poor outcome. Consequently, the development of p53 pathway activating agents is rapidly evolving and gaining more attention in cancer therapeutics research, with several small molecule compounds currently in preclinical and clinical trials. However, it remains largely unknown what types or proportions of p53-mutant tumors will respond to p53 restoration-based therapies.

Using a mouse model of Li Fraumeni syndrome, we genetically restored wild-type …

Mechanism Of Candida Albicans Biofilm And Virulence Inhibition By A Bacterial Secreted Factor, Carrie Graham

Dissertations and Theses (Open Access)

The human microbiome is a diverse polymicrobial population comprised of both fungi and bacteria. Perturbations of the normal microbiome can have a profound impact on health, including the development of infections. Exploitation of these polymicrobial interactions has the potential to provide novel treatment and prevention strategies for infectious diseases. Enterococcus faecalis, a Gram-positive bacterium, and Candida albicans, a polymorphic fungus, occupy overlapping niches as ubiquitous constituents of the gastrointestinal and oral microbiome. Both species are also amongst the most important and problematic, opportunistic nosocomial pathogens and are often co-isolated during infection. Surprisingly, these two species antagonize each other’s …

Mitochondrial Fission After Traumatic Brain Injury, Tara Fischer

Dissertations and Theses (Open Access)

Mitochondrial dysfunction is a central feature in the pathophysiology of Traumatic Brain Injury (TBI). Loss of mitochondrial function disrupts normal cellular processes in the brain, as well as impedes the ability for repair and recovery, creating a vicious cycle that perpetuates damage after injury. To maintain metabolic homeostasis and cellular health, mitochondria constantly undergo regulated processes of fusion and fission and functionally adapt to changes in the cellular environment. An imbalance of these processes can disrupt the ability for mitochondria to functionally meet the metabolic needs of the cell, therefore resulting in mitochondrial damage and eventual cell death. Excessive fission, …

Computational Identification Of Noncoding Driver Mutations Based On Impact On Rna Processing, Kevin Zhu

Dissertations and Theses (Open Access)

Despite the prevalence of mutations in the noncoding regions of the DNA, their effects on cancer development remain largely uninvestigated. This is especially evident when compared to coding mutations, which have been relatively well-studied and, in certain cases, been identified as driver mutations for cancer. Recent studies, however, have identified noncoding mutations that frequently appear in certain types of cancer, which may be evidence that those mutations are important to cancer development. Nonetheless, the role of noncoding mutations in cancer remains unclear. A potential vector for understanding this mechanism is through observing the relation between noncoding mutations and functional RNA …

Integrative Cancer Immunogenomic Analysis Of Serial Melanoma Biopsies Reveals Correlates Of Response And Resistance To Sequential Ctla-4 And Pd-1 Blockade Treatment, Whijae Roh

Dissertations and Theses (Open Access)

Melanoma is the most malignant form of skin cancer. The five-year survival rate for metastatic melanoma is 19.9%. Although targeted therapy of BRAF and MEK inhibitors were developed for melanoma, resistance to therapy is inevitable. Immune checkpoint blockade, which reverses the suppression of the immune system, on the other hand, has shown a durable response in 20-30% of patients with metastatic melanoma. However, more predictive and robust biomarkers of response to this therapy are still needed, and resistance mechanisms remain incompletely understood. To address this, we examined a cohort of metastatic melanoma patients treated with sequential checkpoint blockade against cytotoxic …

Memory Potential, Molecular Characterization, And Translational Applications Of The Novel Theo/Tceo T Cell Phenotype, Todd Bartkowiak, Todd Bartkowiak

Dissertations and Theses (Open Access)

T cells comprise a substantial arm of the immune system and are exquisitely adapted to combat pathogens and tumors. The inflammatory environment largely dictates the nature of T cell response. A hallmark of T cell-mediated immunity is formation of immunological memory; the ability to respond more potently to re-encounter with pathogens. The immune system is also capable of recognizing tumors as foreign, much like viral or bacterial pathogens. Tumors have evolved, though, to generate an immunosuppressive environment to avoid destruction. The field of immunotherapy seeks to overcome immune suppression, in part by targeting T cell co-receptors on the cell surface …

Quality Of Life: Socio-Demographic And Genetic Determinants As Well As Links With Cancer Outcomes, Jeanne Pierzynski

Dissertations and Theses (Open Access)

Quality of life (QOL) is an independent prognostic factor for cancer. Lung cancer is the leading cause of cancer death. Breast cancer is the most diagnosed. Bladder cancer is the most expensive cancer to treat because of its high recurrence rate. We set to perform comprehensive analyses of predictors of QOL in these cancer sites with the future goal of improving QOL and outcomes.

In 6,456 newly diagnosed lung cancer patients, we investigated the relationship between baseline patient characteristics and QOL to identify determinants of QOL. A QOL questionnaire (SF-12v1) measured patients’ physical component summary (PCS) and mental component summary …

Dynamic Assessment Of Nk Cell Interactions With Pediatric Tumor Cells To Predict Response To Immunotherapy, Arianexys Aquino Lopez

Dissertations and Theses (Open Access)

Due to Natural Killer (NK) cells’ capacity to target tumor cells without prior sensitization, adoptive NK cell therapy represents a promising immunotherapy approach for pediatric cancer patients. Our laboratory has developed an NK cell expansion protocol that generates large quantities of NK cells for therapeutic infusion. Given that NK cells are heterogeneous, with variable receptor expression and potential to target tumor cells, the purpose of my study was to determine whether subpopulations of NK cells with enhanced anti-tumor potential could be identified for increased potency of the NK cell infusion product. In addition, we previously showed that our expanded NK …

Characterization Of Notch1 And Pi3k-Pten-Akt/Mtor Pathway Interaction In Head And Neck Squamous Cell Carcinoma, Kyriante' Henry

Dissertations and Theses (Open Access)

Head and neck squamous cell carcinoma (HNSCC) affects various mucosal sites of the upper aerodigestive tract, including the nasal and oral cavities, the nasopharynx, and the oropharynx. More than five hundred thousand new cases of HNSCC occurred in 2011 alone, with 50,000 reported cases in the United States. This trend made HNSCC the seventh most common non-skin cancer worldwide (Ferlay et al., 2015). Although significant epidemiological and pathological advancements have been made, survival rates have not improved much over the last 40 years, leaving a mortality rate that remains at approximately 50%. An unbiased drug screen demonstrated that HNSCC cell …

The Functions Of Setd5 And Mir-221 In Embryonic Stem Cell Differentiation, Tsai-Yu Chen

Dissertations and Theses (Open Access)

Embryonic stem cells (ESCs) are a widely used model system to study cellular differentiation because of their pluripotent characteristics, and ESC differentiation is an epigenetic process. In an effort to identify a new epigenetic factor that is required for ESC differentiation, the function of SETD5 in ESCs was studied for this thesis. Results show that SETD5 is essential for retinoic acid (RA)-induced differentiation of mouse ESCs and for RA-induced expression of critical developmental genes (e.g., Hoxa1 and Hoxa2) and neuron-related genes (e.g., Nestin and Pax6). SETD5 was upregulated during ESC differentiation. Additional results demonstrated that SETD5 bound to …

Circulating Autoantibodies In Human Traumatic Spinal Cord Injury Subjects And Their Relationship To The Development Of Neuropathic Pain, Georgene Hergenroeder

Dissertations and Theses (Open Access)

Background:

Approximately 17,500 spinal cord injuries (SCI) occur yearly in the U.S. causing considerable morbidity and mortality. Neuropathic pain (NP) ensues in 40-70% of SCI. An autoimmune response resulting from disruption of the blood-spinal cord-barrier may be a contributor to NP. However, the relationship between autoantibodies and NP after SCI in humans has not been thoroughly characterized nor have autoantigens been identified. Glial fibrillary acidic protein (GFAP) and collapsin response mediator protein2 (CRMP2) were identified as candidate autoantigens. The hypothesis is that proteins from the injured spinal cord released by SCI trigger autoantibody production which can lead to the development …