Determining The Mechanisms Generating Soluble Il-15 Complexes, Scott Anthony

Dissertations and Theses (Open Access)

A diverse assortment of infectious pathogens and TLR agonists enhance the expression of Interleukin (IL)-15. Additionally, inducing lymphopenia enhances anti-tumor responses in an IL-15-dependent manner. Paradoxically, despite the limited expression of IL-15 during homeostasis, the role of IL-15 during the steady state is well-known, while its roles during inflammation and infections remain largely undefined. IL-15 uses a unique method of production and presentation to support the development and homeostasis of NK and CD8 T cells. IL-15 is produced with its high affinity IL-15Rα and this IL-15Rα/IL-15 complex is shuttled to the cell surface where it is presented in-trans or cleaved …

The Tumor Suppressor Notch Inhibits Head And Neck Squamous Cell Carcinoma (Hnscc) Tumor Growth And Progression By Modulating Proto-Oncogenes Axl And Ctnnal1 (Α-Catulin), Shhyam Moorthy, Shhyam Moorthy

Dissertations and Theses (Open Access)

Background: Head and Neck Squamous Cell Carcinoma (HNSCC) is the sixth most common malignancy worldwide, with roughly 300,000 cancer related deaths occurring globally each year. The survival of patients with HNSCC has not changed significantly over the past decade, leading investigators to search for promising molecular targets. To identify new treatment targets and biomarkers that could better guide therapy, we previously characterized the genomic alterations from primary HNSCC patient samples. We were among the first to discover that NOTCH1 is one of the most frequently mutated genes in this cancer type. The spectrum of inactivating NOTCH1 mutations in HNSCC suggested …

Voxel-Level Absorbed Dose Calculations With A Deterministic Grid-Based Boltzmann Solver For Nuclear Medicine And The Clinical Value Of Voxel-Level Calculations, Justin Mikell

Dissertations and Theses (Open Access)

Voxel-level absorbed dose (VLAD) is rarely calculated for nuclear medicine (NM) procedures involving unsealed sources or 90Y microspheres (YM). The current standard of practice for absorbed dose calculations in NM utilizes MIRD S-values, which 1) assume a uniform distribution in organs, 2) do not use patient specific geometry, and 3) lack a tumor model. VLADs overcome these limitations. One reason VLADs are not routinely performed is the difficulty in obtaining accurate absorbed doses in a clinically acceptable time. The deterministic grid-based Boltzmann solver (GBBS) was recently applied to radiation oncology where it was reported as fast and accurate for both …

Normal Glycolytic Enzyme Activity Is Critical For Hypoxia Inducible Factor-1a Activity And Provides Novel Targets For Inhibiting Tumor Growth, Geoffrey Grandjean Phd

Dissertations and Theses (Open Access)

Normal Glycolytic Enzyme Activity is Critical for Hypoxia Inducible Factor-1α Activity and Provides Novel Targets for Inhibiting Tumor Growth

By Geoffrey Grandjean

Advisory Professor: Garth Powis, D. Phil

Unique to proliferating cancer cells is the observation that their increased need for energy is provided by a high rate of glycolysis followed by lactic acid fermentation in a process known as the Warburg Effect, a process many times less efficient than oxidative phosphorylation employed by normal cells to satisfy a similar energy demand ^[1]. This high rate of glycolysis occurs regardless of the concentration of oxygen in the cell and …

Redirecting T Cells With Chimeric Antigen Receptors To Target Cd123+ Leukemia, Radhika Thokala

Dissertations and Theses (Open Access)

ABSTRAC

REDIRECTING T CELLS WITH CHIMERIC ANTIGEN RECEPTORS TO TARGET CD123+ LEUKEMIA

Radhika Thokala, Ph.D*

Advisory Professor: Dean Anthony Lee, M.D, Ph.D

CD123 or interleukin receptor alpha (IL-3Rα) is expressed on hematological malignancies such as acute myeloid leukemia (AML) and some acute lymphoblastic leukemia (ALL). Significantly, CD123 is over-expressed on leukemic stem cells (LSCs) compared to normal hematopoietic stem cells and thus targeting this tumor- associated antigen (TAA) provides the potential to prevent relapse. The prototyical chimeric antigen receptor (CAR) is fashioned by …

Molecular Regulation Of Vascular Calcification In Murine Models Of Atherosclerosis, Shanshan Gao

Dissertations and Theses (Open Access)

Background: Calcification occurs often in the atherosclerotic lesions of patients with coronary heart disease and animals with hypercholesterolemia, such as apolipoprotein-E deficient (ApoE-/-) mice. However, the mechanism(s) underlying the development of calcification in atherosclerosis remains unclear. ApoE acts as a lipid transporter, but also has been recognized as a potential regulator of osteogenesis. Little information is available as to whether ApoE has any direct impact on osteogenesis and calcification in vascular smooth muscle cells (VSMC). Several signal transduction pathways play a role in regulation of calcification, including the Wnt/β-catenin system and potentially GTAP, an ubiquitin-conjugating enzyme responsible for protein …

Effects Of Pharmacological And Genetic Disruption Of Chemokine Receptor Cxcr4 In B-Cell Acute Lymphoblastic Leukemia, Shubhchintan Randhawa

Dissertations and Theses (Open Access)

The CXCR4 chemokine receptor plays a pivotal role in homing and retention of B-cell Acute Lymphoblastic Leukemia cells to bone marrow niches. The bone marrow stromal cells (BMSCs) constitutively secrete the CXCR4 ligand CXCL12, thus attracting leukemia cells and protecting them from cytotoxic drugs, a mechanism that might be responsible for minimal residual disease after conventional chemotherapy against B-ALL. Indeed, in this study we observed that B-ALL cells that had migrated beneath the BMSCs were highly resistant to chemotherapeutic drugs. Inhibition of CXCR4 to disrupt this interaction presents itself as an attractive target to overcome bone marrow derived drug resistance …

Defining The Molecular Networks Necessary For Thymus Fate And Organogenesis, Kaitlin A. Reeh

Dissertations and Theses (Open Access)

The thymus and parathyroid (PT) glands originate from endodermal progenitors in the bilateral third pharyngeal pouches (3^rd pps). By E11.5 during mouse development, cells committed to the thymus lineage express Foxn1 whereas PT-fated cells express Gcm2. While these transcription factors are required for organ-specific differentiation, the exact molecular mechanisms that specify endodermal progenitors to either the thymus or parathyroid lineage are not well defined. Tbx1 is initially expressed throughout the 3^rd pp endoderm, as it is required for segmentation of the pharyngeal apparatus, but is downregulated in the thymus-fated domain by E10.5. Despite the widely held notion …

Designing For Practice Development In A Social Learning System: Communicating Norms And Vicarious Experience, Claire Loe

Dissertations and Theses (Open Access)

Over the past quarter century, the United States has experienced an increase in demand for health services. Expanded use of community health workers (CHWs) has been identified as a strategic response for more effective distribution of healthcare resources by alleviating pressures on clinical personnel and infusing prevention education into the community-to-clinical care continuum. Expansion of the CHW workforce poses many challenges. For CHWs to effectively reduce costs and pressures on the healthcare system, ‘expansion’ implies not only increasing their numbers, but also assuring a workforce that has the capacity to perform in diverse settings. I propose a theoretical framework for …

Prevalence Of Steroid-Induced Hyperglycemia In Patients With Mantle Cell Lymphoma Receiving High Dose Steroids, Veronica Brady

Dissertations and Theses (Open Access)

Background

Hyperglycemia as a result of glucocorticoid administration (steroid-induced hyperglycemia [SIH]) occurs in 32-37% of adult patients with cancer both with and without previous history of diabetes. Patients diagnosed with mantle cell lymphoma (MCL) are often treated with chemotherapy regimens that include high dose steroids as first line therapy. Little is known about the prevalence of steroid-induced hyperglycemia in patients with MCL receiving high dose steroids. Moreover it is not known if how the resulting hyperglycemia is managed impacts time to relapse or death.

Purpose

The primary aim of this study was to determine the prevalence of SIH in MCL …

Improving Attenuation Correction In Hybrid Positron Emission To Mography, Hua Asher Ai

Dissertations and Theses (Open Access)

Hybrid positron emission tomography imaging techniques such as PET/CT and PET/MR have undergone significant developments over the last two decades and have played increasingly more important roles both in research and in the clinic. A unique advantage PET has over other clinical imaging modalities is its capability of accurate quantification. However, as the most critical component of PET quantification, attenuation correction in hybrid PET systems is challenged in several different aspects, including the spatial- temporal mismatch between the PET emission images and the associated attenuation images provided by the complementary modality, and the difficulty in bone identification in the MR-based …

Gating Mechanisms Of The Canonical Trp Channel Isoform Trpc4, Dhananjay P. Thakur

Dissertations and Theses (Open Access)

Non-selective cation channels formed by Transient Receptor Potential Canonical (TRPC) proteins play important roles in regulatory and pathophysiological processes. These channels are known to be activated downstream from phospholipase C (PLC) signaling. However, the mechanism by which the PLC pathway activates TRPC4/C5 remains unclear. Uniquely, TRPC4 is maximally activated only when two separate G protein pathways, G_q/11 and G_i/o, are co-stimulated, making it a coincidence detector of G_q/11- and G_i/o -coupled receptor activation. Using HEK293 cells co-expressing mouse TRPC4β and selected G protein-coupled receptors, I observed that coincident stimulation of G_i/o proteins and …

Investigating The Role Of Cholesterol Metabolism And Synthesis In Metastasis And Radiation Response In Aggressive Subtypes Of Breast Cancer, Adam Wolfe

Dissertations and Theses (Open Access)

Aggressive breast cancers, triple-negative breast cancer (TNBC) and inflammatory breast cancer (IBC), metastasize at a high rate and are notoriously resistant to standard treatments. Research has shown diets high in cholesterol increase the incidence of aggressive breast cancers and pre-clinical research has shown cholesterol can fuel the growth of breast cancer in vivo. Studies at MD Anderson have shown that IBC patients taking cholesterol lowering drugs, statins, have improved survival outcomes, and also statins can improve the response to radiation in vitro. Furthermore, statins have been shown to target the cells with stem like-properties called cancer stem cells (CSCs) which …

Reduction Of Dose Calculation Errors For Patients With Metal Implants Receiving Photon Radiation Therapy, Jessie Huang-Vredevoogd

Dissertations and Theses (Open Access)

Many patients receiving external beam radiation therapy have metal implants that can affect their treatment, and these metal implants can degrade the accuracy of dose calculations. Dose calculation errors result from limitations of modern dose calculation algorithms in modeling metal/tissue interface effects. Metals also cause streak artifacts in the computed tomography (CT) images that are used for treatment planning, and these artifacts can also degrade dose calculation accuracy. Metal based-energy deposition kernels are a potential solution for the calculation errors associated with the limitations of the convolution/superposition (C/S) dose calculation method as they better model photon interactions and scatter in …

New Insights On The Role Of Jmjd2a In Cancer Progression, Yuan Gao

Dissertations and Theses (Open Access)

Changes in chromatin architecture are known to be one of the underlying causes of cancer because of its ability to alter gene transcription. Histone methylation is one of the most intricate epigenetic marks because it adds multiple layers of modification on the targeted sites. Therefore, many studies have brought histone methylases and demethylases into focus, hoping to decipher their roles in cancer progression. Among these enzymes, JMJD2A is the first to shown to have demethylation activity against trimethylation, and to regulate gene expression, development, and cancer progression. While many studies have mainly focused on its role in transcriptional regulation, only …

Feasibility Of Using Virtual Unenhanced Images To Replace Pre-Contrast Images In Multiphase Renal Ct Examinations, Dawn Olivia Popnoe

Dissertations and Theses (Open Access)

Multiphase renal CT exams are a commonly used imaging technique for the diagnosis of renal masses. The pre-contrast, or true unenhanced (TUE), image provides a baseline for enhancement measurements which is an important criteria used to characterize renal lesions, consequently it is crucial that CT numbers measured in TUE images be accurate. The purpose of this work is to assess the feasibility of replacing TUE with virtual unenhanced (VUE) images derived from DECT data in renal CT exams. Eliminating TUE image acquisition would reduce patient dose and increase patient throughput, improving clinical efficiency.

A retrospective study was conducted for 60 …

Identification Of Familial Wilms Tumor Predisposition Genes Using Whole Genome Sequencing, Timothy B. Palculict

Dissertations and Theses (Open Access)

Wilms tumor, a childhood tumor arising from undifferentiated renal mesenchyme, is diagnosed in North America at a frequency of 1 in 10,000 live births and accounts for 5% of all pediatric cancers. The etiology of Wilms tumor is heterogeneous with multiple genes known to have an effect on Wilms tumor development; however, these genes are rarely associated with familial Wilms tumor. Gene mutations in WT1, WTX, CTNNB1 and TP53 are observed in a third of sporadic tumors, while the causative gene(s) responsible for familial Wilms tumor are largely unknown. Approximately 2% of Wilms tumor patients have a family …

Merlin Mediated Regulation Of Hair Follicle Morphogenesis, Megan K. Fentress

Dissertations and Theses (Open Access)

Epidermal homeostasis is paramount for the ongoing function of the skin as the primary barrier between a mammalian organism and the external environment. Homeostasis is achieved through a complex and delicate balance of cell death, cell proliferation and cell differentiation. Critical for regeneration and maintenance of the skin are epidermal stem cells. Within the epidermis two distinct stem cell compartments exist, the bulge and interfollicular/basal stem cell niches, which play a central role in the regeneration of the epidermis through self-renewal and contribution to the differentiated cells of the epidermis. The bulge stem cell niche is established early in epidermal …

Ex Vivo Expanded Cord Blood Natural Killer Cells As A Novel Therapeutic For Multiple Myeloma, Nina Shah

Dissertations and Theses (Open Access)

Multiple myeloma (MM) is the second most common hematologic malignancy in adults and, to date, is incurable. Allogeneic natural killer (NK) cells are active in various hematologic malignancies and may have a role against MM. Umbilical cord blood is a potential source for allogeneic NK cells and ex vivo expanded umbilical cord blood-derived NK (CB-NK) cells demonstrate activity comparable to that of peripheral blood-derived NK cells. However, large-scale expansion of these cells is required for clinical translation. Here we studied a potential method for ex vivo expansion of NK cells from fresh and cryopreserved CB. Using artificial antigen presenting cells …

In Vivo Significance Of The Mdm4 And P73 Interaction During Development And Tumorigenesis, Mehrnoosh Tashakori

Dissertations and Theses (Open Access)

The tumor suppressor protein p53 is negatively regulated by Mdm4 protein. The significance of such regulation was determined from mouse models. Mdm4-deficient mice are embryonic lethal at E7.5 in a p53-dependent manner. p73, a member of the p53-family, is a transcription factor with tumor suppressor activity. In vitro studies show that Mdm4 binds to p73 and, further, comprehensive biochemical studies revealed that Mdm4 has higher affinity for p73 than p53. However, little is known about the significance of the Mdm4 and p73 interaction in vivo. This study aimed to elucidate the biological consequences of this interaction during embryogenesis …

Methylation Of Egfr By Arginine Methyltransferase Prmt1 Enhances Egfr Signaling And Cetuximab Resistance, Hsin-Wei Liao

Dissertations and Theses (Open Access)

Protein modifications of epidermal growth factor receptor (EGFR) intracellular domain are well known regulators of EGFR functions whereas those of its extracellular domain remain relatively unexplored. Here, we report that methylation at R198 and R200 of EGFR extracellular domain by protein arginine methyltransferase 1 (PRMT1) upregulates its binding to EGF and subsequent receptor dimerization and signaling activation. Methylation-defective EGFR mutant reduced tumor growth in mouse orthotopic xenograft model. Importantly, increased EGFR methylation sustains its signaling activation and cell proliferation in the presence of therapeutic EGFR monoclonal antibody, cetuximab. EGFR methylation level also correlates with higher recurrence rate after cetuximab treatment …

Investigating The Interaction Of Aurka And Ube2c In Colorectal Cancer Cells, Apurva M. Hegde

Dissertations and Theses (Open Access)

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths in the US. Among the many genomic aberrations previously implicated in colorectal cancer, recurrent amplification of chromosome 20q is frequently associated with liver metastasis. Previous research in our lab identified a gene signature on chromosome 20q associated with colorectal cancer progression. In this study, one of the genes in the signature, the ubiquitin conjugating enzyme UBE2C, was identified through preliminary bioinformatics analysis as a candidate for further examination of its role in CRC progression. Co-expression analysis of UBE2C in tumor-normal datasets from the public database Oncomine revealed all the …

Quality Assurance Of Advanced Treatment Modalities Using Presage® Dosimeters, Ryan G. Lafratta

Dissertations and Theses (Open Access)

Computer-controlled therapy machines allow for increasingly complex plans, as there are more variables that can be tuned to produce the ideal result. This makes it increasingly difficult to assure the intended calculated dose is being delivered correctly using current techniques that are 2D-based because the resultant dose distributions can differ markedly in various sections of the target. A measurement of composite dose from the entire plan should be included in patient-specific IMRT QA. A volumetric dosimeter such as PRESAGE^® is able to provide a complete 3D measured dosimetry dataset with one treatment plan delivery. It was hypothesized that a …

Prophylactic Cranial Irradiation Reduces The Incidence Of Brain Metastasis In A Mouse Model Of Metastatic Breast Cancer, Daniel L. Smith

Dissertations and Theses (Open Access)

Prophylactic cranial irradiation (PCI) is a preventative whole-brain irradiation technique used to reduce the incidence of brain metastasis and improve overall survival in select patients with small cell lung cancer and acute lymphoblastic leukemia. A population of breast cancer patients – stage IV, HER2+ or triple-negative – has emerged as having a high risk of developing brain metastases. Because only 10-20% of breast cancer patients diagnosed with brain metastases survive longer than one year, in this high-risk population the benefit of PCI – potential for reduced incidence of brain metastasis and improved overall survival – may outweigh the risks – …

Metabolic Profiling Of Prions In The Gastro-Intestinal Tract, Uffaf Khan

Dissertations and Theses (Open Access)

Metabolic profiling of prions in the gastro-intestinal tract

Uffaf Khan, B.S.

Thesis Advisor: Claudio Soto, Ph.D.

Abstract

Prion diseases, also known as transmissible spongiform encephalopathies (TSEs), are a group of debilitating neurodegenerative disorders that affect both humans and animals. They can be spread by horizontal transmission as seen in chronic wasting disease in deer and elk population. In addition, transmission to humans has also been documented which includes bovine spongiform encephalopathy in cattle to variant Creutzfeldt-Jakob disease in humans due to consumption of contaminated meat. The most probable natural route of transmission is by oral consumption of infectious material. Even …

Ankyrin-B And Mtor Complex 1 In The Regulation Of Electrical Activities In The Heart, Henry C. Wu, Henry C. Wu

Dissertations and Theses (Open Access)

The mammalian target of rapamycin complex 1 (mTORC1) activity is paramount in the regulation of electrical activities in the brain and the heart. In the brain, the tumor suppressor gene TSC2 encodes the protein product tuberin that interacts with hamartin to form a heterodimer Tuberous Sclerosis Complex (TSC) that regulates mTORC1. When TSC2 is disrupted, mTORC1 activity becomes dysregulated resulting in abnormal electrical activities in the brain manifesting in the form of epileptic seizures. In the heart, mTORC1 activity is triggered by a sustained increase in hemodynamic pressure causing the heart to electrically remodel. A likely candidate serving as the …

Detection Of Genes Influencing Chronic And Mendelian Disease Via Loss-Of-Function Variation, Alexander H. Li

Dissertations and Theses (Open Access)

A typical human exome harbors dozens of loss-of-function (LOF) variants predicted to severely disrupt or abolish gene function. These variants are enriched at the extremely rare end of the allele frequency spectrum (< 0.1%), suggesting purifying selection against these sites. However, most previous population-based sequencing studies have not included analysis of genotype-phenotype relationships with LOF variants. Thus, the contribution of LOF variation to health and disease within the general population remains largely uncharacterized.

Using whole exome sequence from 8,554 participants in the Atherosclerosis Risk in Communities (ARIC) study, we explored the impact of LOF variation on a broad spectrum of human phenotypes. First, we selected 20 common chronic disease risk factor phenotypes and performed gene-based association tests. Analysis of this sample verified two relationships in well-studied genes (PCSK9 and APOC3) and identified eight new loci. Novel relationships included …

Computational Modeling Of Rna-Small Molecule And Rna-Protein Interactions, Lu Chen

Dissertations and Theses (Open Access)

The past decade has witnessed an era of RNA biology; despite the considerable discoveries nowadays, challenges still remain when one aims to screen RNA-interacting small molecule or RNA-interacting protein. These challenges imply an immediate need for cost-efficient while predictive computational tools capable of generating insightful hypotheses to discover novel RNA-interacting small molecule or RNA-interacting protein. Thus, we implemented novel computational models in this dissertation to predict RNA-ligand interactions (Chapter 1) and RNA-protein interactions (Chapter 2).

Targeting RNA has not garnered comparable interest as protein, and is restricted by lack of computational tools for structure-based drug design. To test the potential …

Regulation Of Autoimmune Germinal Center Reaction By Tfh Cells And Application Of Tfr-Like Cells For The Treatment Of Autoimmune B Cell Responses, Young Uk Kim

Dissertations and Theses (Open Access)

Excessive follicular helper T (Tfh) cell responses to self-antigens are associated with antibody-mediated autoimmune diseases in humans including systemic lupus erythematosus (SLE). Numeral and functional aberrations of T regulatory T (Treg) cells are common in patients with autoimmune diseases. Although different types of immunosuppressive agents have been used clinically to treat antibody-mediated autoimmune diseases, they generally have side effects due to the lack of target-specificity. To minimalize the adverse effects, there is a need to develop target-specific therapeutics which specifically control auto-reactive B cell responses and auto-reactive Tfh cell responses. Recent studies unveiled that Foxp3⁺ Treg cells expressing CXCR5 …

Quantification Of Imrt Severity Scores For Improvement Of Fmea Results, Jacqueline T. Faught

Dissertations and Theses (Open Access)

Accurate delivery of intensity modulation radiation therapy (IMRT) requires perfect execution of a long, complicated chain of events; failure of any component of this process may contribute to dose delivery errors, compromising treatment quality and, more importantly, patient safety. Prospective, process-wide risk mitigation techniques are becoming more prevalent in radiotherapy to establish comprehensive quality management (QM) programs, such as failure modes and effects analysis (FMEA). The subjective nature of the ordinal scores used for FMEA leads questionable reliability and validity of the results. Additionally, physics components are commonly grouped together, leaving out valuable details important to physics QM. While the …