Medicine and Health Sciences Commons^™

Introducing Novel Combinatorial Targeted Therapies In Multiple Types Of Cancer, Mehrad Tavallai

Theses and Dissertations

The cancers of liver, colon and breast are amongst the top five most prevalent and most fatal worldwide. As the Raf/MEK/ERK pathway is frequently deregulated in hepatocellular carcinoma (HCC), sorafenib, a Raf kinase inhibitor, became the first systemic therapy approved for the treatment of patients with HCC. However, sorafenib only produced modest effects with low response rates in the clinic. Similarly, regorafenib, which was approved for the treatment of metastatic colorectal cancer (CRC), has had a poor response rate in the clinic. Since phosphodiesterase type 5 has been reported to be overexpressed in HCC and CRC, we hypothesized that sildenafil, …

Resolution Of Inflammation Rescues Axon Initial Segment Disruption, Nicholas M. George

Theses and Dissertations

Axonal domains are required for proper neuron function. These domains are unstable and degenerate concurrent with the inflammation in multiple sclerosis (MS) and the inflammatory disease models experimental autoimmune encephalomyelitis (EAE) and lipopolysaccharide (LPS) induced inflammation. Previous studies from our laboratory have shown that the axon initial segment (AIS) is maintained independently of the presence of myelin, but that AIS disruption is seen in MS as well as EAE and LPS-mediated inflammation. AIS loss can be interrupted in the early stage of EAE using the anti-inflammatory drug Didox. However, the potential for Didox directed repair of the AIS in later …

Examining Genetic And Environmental Influences On Alcohol Use And Externalizing Behaviors In African American Adolescents, Neeru Goyal

Theses and Dissertations

The aim of this thesis is to expand our understanding of the etiology of alcohol misuse and related disorders in African Americans using genetically informative study designs. Specifically, we take advantage of the candidate-gene approach and polygenic score analysis to extend the literature specific to African American populations. Chapter 2 explores gene x environment (GxE) interactions through the candidate gene approach to explore the relationship between two genes chosen on their potential relevance to stress response and adolescent alcohol use and misuse, among African American youth living in highly impoverished neighborhoods, as moderated by stressful life events. Chapter 3 implements …

Power Analysis In Applied Linear Regression For Cell Type-Specific Differential Expression Detection, Edmund Glass

Theses and Dissertations

The goal of many human disease-oriented studies is to detect molecular mechanisms different between healthy controls and patients. Yet, commonly used gene expression measurements from any tissues suffer from variability of cell composition. This variability hinders the detection of differentially expressed genes and is often ignored. However, this variability may actually be advantageous, as heterogeneous gene expression measurements coupled with cell counts may provide deeper insights into the gene expression differences on the cell type-specific level. Published computational methods use linear regression to estimate cell type-specific differential expression. Yet, they do not consider many artifacts hidden in high-dimensional gene expression …

Investigating The Molecular Etiologies Of Sporadic Als (Sals) Using Rna-Sequencing, David G. Brohawn

Theses and Dissertations

ALS is an often lethal disease involving degeneration of motor neurons in the brain and spinal cord. Current treatments only extend life by several months, and novel therapies are needed. We combined RNA-Sequencing, systems biology analyses, and molecular biology assays to elucidate sporadic ALS group-specific differences in postmortem cervical spinal sections (7 sALS and 8 control samples) that may be relevant to disease pathology. >55 million 2X150 RNA-sequencing reads per sample were generated and processed.

In Chapter 2, we used bioinformatics tools to identify nuclear differentially expressed genes (DEGs) between our two groups. Further, we used Weighted Gene Co-Expression Network …

Role Of Vav2 In Podocyte Inflammasome Activation And Glomerular Injury During Hyperhomocysteinemia, Sabena Conley

Theses and Dissertations

Hyperhomocysteinemia (hHcys) is a widely known pathogenic factor in the progression of end-stage renal disease (ESRD) and it is also associated with an increased risk for injurious cardiovascular pathologies during ESRD. HHcys is linked to the formation and activation of the NOD-like receptor protein 3 (NLRP3) inflammasome, characterized as a critical early mechanism initiating the inflammatory response. NADPH oxidase (NOX)-derived reactive oxygen species (ROS) mediate the activation of the NLRP3 inflammasome in podocytes in response to elevated levels of homocysteine (Hcys) in vitro and in vivo. However, it remains unknown how NLRP3 inflammasome activation is triggered by NOX. The …

The Effect Of Pre-Deployment Physiology As A Predictor Of Post-Traumatic Stress Disorder Among A Sample Of United States Army National Guard And Reserve Soldiers, David J. Rothman

Theses and Dissertations

Potential risk factors for development of Post-Traumatic Stress Disorder (PTSD) are still unclear. One potential risk factor for the development of PTSD is an individual’s cardiovascular reactivity and recovery in response to stressor tasks. The current study was conducted with 763 Army National Guard and Army Reserve soldiers. Participants completed a stressful induction along with self-report measures prior to deployment. Post-deployment, self-report measures were completed to assess PTSD symptomatology and experiences related to deployment and combat. Multiple regression was used to determine the ability of blood pressure response to stress to predict PTSD symptoms immediately and one-year after return from …

The Study Of The Regulon Of Oxyr In Escherichia Coli And Porphyromonas Gingivalis, Christopher K. Pham

Theses and Dissertations

The facultative anaerobe, Escherichia coli and the obligate anaerobe, Porphyromonas gingivalis are two bacteria that reside in our body. Although they reside in separate environments, they are both subject to hydrogen peroxide stress and have mechanisms to regulate the stress. OxyR is the primary transcriptional regulator/sensor of oxidative stress response caused by hydrogen peroxide. OxyR in P. gingivalis is not well-characterized compared to OxyR in E. coli. We sought to characterize and compare the two forms of OxyR in order to gain a better understanding of the protein. We determined the oligomeric state of both proteins: primarily a tetramer for …

Characterization Of A Novel Protease In Staphylococcus Aureus, Adam L. Johnson

Theses and Dissertations

A newly discovered cysteine protease, Prp, has been shown to perform an essential, site-specific cleavage of ribosomal protein L27 in Staphylococcus aureus. In Firmicutes and related bacteria, ribosomal protein L27 is encoded with a conserved N-terminal extension that must be removed to expose residues critical for ribosome function. Uncleavable and pre-cleaved variants were unable to complement an L27 deletion in S. aureus, indicating that this N-terminal processing event is essential and likely plays an important regulatory role. The gene encoding the responsible protease (prp) has been shown to be essential, and is found in all organisms …

Immunotherapy Of Cancer: Reprogramming Tumor/Immune Cellular Crosstalk To Improve Anti-Tumor Efficacy, Kyle K. Payne

Theses and Dissertations

Immunotherapy of cancer has been shown to be promising in prolonging patient survival. However, complete elimination of cancer and life-long relapse-free survival remain to be major challenge for anti-cancer therapeutics. We have previously reported that ex vivo reprogramming of tumor-sensitized immune cells by bryostatin 1/ionomycin (B/I) and the gamma-chain (γ-c) cytokines IL-2, IL-7, and IL-15 resulted in the generation of memory T cells as well as CD25+ NKT cells and CD25+ NK cells. Adoptive cellular therapy (ACT) utilizing these reprogrammed immune cells protected FVBN202 mice from tumor challenge, and overcame the suppressive functions of myeloid-derived suppressor cells (MDSCs). We then …

Elaboration And Design Of Α7 Nachr Negative Allosteric Modulators, Osama I. Alwassil

Theses and Dissertations

α7 Neuronal nicotinic acetylcholine receptors are one of two major classes of receptors responsible for cholinergic neurotransmission in the central nervous system. The existence of α7 neuronal nAChRs in different regions of the nervous system suggests their involvement in certain essential physiological functions as well as in disorders such as Alzheimer’s disease (AD), drug dependence, and depression. This project was aimed toward the discovery and development of small–molecule arylguanidines that modulate α7 nAChR function with improved subtype-selectivity through an allosteric approach. Identifying the required structural features of these small molecules allowed optimization of their negative allosteric modulator (NAM) actions at …

Elucidation Of A Novel Pathway In Staphylococcus Aureus: The Essential Site-Specific Processing Of Ribosomal Protein L27, Erin A. Wall

Theses and Dissertations

Ribosomal protein L27 is a component of the eubacterial large ribosomal subunit that has been shown to play a critical role in substrate stabilization during protein synthesis. This function is mediated by the L27 N-terminus, which protrudes into the peptidyl transferase center where it interacts with both A-site and P-site tRNAs as well as with 23S rRNA. We observed that L27 in S. aureus and other Firmicutes is encoded with a short N-terminal extension that is not present in most Gram-negative organisms, and is absent from mature ribosomes. The extension contains a conserved cleavage motif; nine N-terminal amino acids are …

Effects Of Hiv-1 Tat On The Enteric Nervous, Joy Ngwainmbi

Theses and Dissertations

More than 1.2 million people are estimated to be currently living with the human immunodeficiency virus (HIV) in the United States of America. The gastrointestinal (GI) tract is both a major target and an important component of HIV pathogenesis. The GI processes that are dysregulated during HIV infection are controlled by the enteric nervous system (ENS). Indeed, both clinical and experimental studies have implicated the ENS in HIV and simian immunodeficiency virus (SIV) pathogenesis. In addition to direct viral effects, the HIV virus also indirectly affects the GI tract via cellular and/or viral toxins released by infected cells. Trans-activator of …

Effects Of Tgf-Β1 And Il-33 On Mast Cell Function, Victor S. Ndaw

Theses and Dissertations

TGFβ is involved in many pathological conditions, including autoimmune disorders, cancer, and cardiovascular and allergic diseases. We have previously found that TGFβ can suppress IgE-mediated mast cell activation in human and mouse mast cells in vitro. IL-33 is a recently discovered member of the IL-1 family capable of inducing mast cell responses and enhancing IgE-mediated activation. In this study, we investigated the effects of TGFβ on IL-33-mediated mast cell activation. Bone marrow-derived mast cells cultured in TGFβ -1, -2, or -3 showed reduced IL-33-mediated production of TNF, IL-6, IL-13 and MCP-1, in a concentration-dependent manner. Furthermore, TGFβ also reduced …

Xlf-Dependent Nonhomologous End Joining Of Complex Dna Double-Strand Breaks With Proximal Thymine Glycol And Screening For Xrcc4-Xlf Interaction Inhibitors, Mohammed Al Mohaini

Theses and Dissertations

DNA double-strand breaks induced by ionizing radiation are often accompanied by ancillary oxidative base damage that may prevent or delay their repair. In order to better define the features that make some DSBs repair-resistant, XLF-dependent nonhomologous end joining of blunt-ended DSB substrates having the oxidatively modified nonplanar base thymine glycol (Tg) at the first (Tg1) , second (Tg2), third (Tg3) or fifth (Tg5) positions from one 3’ terminus was examined in human whole-cell extracts. Tg at the third position had little effect on end-joining even when present on both ends of the break. However, Tg as the terminal or penultimate …

The Characterization Of A Putative Virulence Factor Expressed By Sneathia Amnii, Amy Sanford

Theses and Dissertations

Preterm birth, defined at birth before 37 weeks gestation, affects millions of newborns worldwide every year. Preterm birth is a leading cause of infant morbidity and mortality. One major cause of preterm birth is preterm premature rupture of membranes (PPROM), which can be triggered by bacterial infection and inflammation. A bacterial species that has been implicated in preterm birth and other obstetric complications is Sneathia amnii. The goals of this study were to observe cytopathogenic effects caused by S. amnii strain Sn35 and identify putative virulence factors causing those effects. Sn35 was able to adhere to, invade, and damage/kill …

Proof-Of-Concept Of Environmental Dna Tools For Atlantic Sturgeon Management, Jameson Hinkle

Theses and Dissertations

Abstract

The Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus, Mitchell) is an anadromous species that spawns in tidal freshwater rivers from Canada to Florida. Overfishing, river sedimentation and alteration of the river bottom have decreased Atlantic Sturgeon populations, and NOAA lists the species as endangered. Ecologists sometimes find it difficult to locate individuals of a species that is rare, endangered or invasive. The need for methods less invasive that can create more resolution of cryptic species presence is necessary. Environmental DNA (eDNA) is a non-invasive means of detecting rare, endangered, or invasive species by isolating nuclear or mitochondrial DNA (mtDNA) from the …

Functional Characterization Of Rai1 In Zebrafish, Joshua S. Beach

Theses and Dissertations

Smith-Magenis Syndrome (SMS; OMIM #182290) is a multiple congenital abnormality and intellectual disability (ID) disorder caused by either an interstitial deletion of the 17p11.2 region containing the retinoic acid induced-1 (RAI1) gene or a mutation of the RAI1 gene. Individuals diagnosed with SMS typically present characteristics such as ID, self-injurious behavior, sleep disturbance, ocular and otolaryngological abnormalities, craniofacial and skeletal abnormalities, neurological and behavioral abnormalities, as well as other systemic defects and manifestations. Previous work by Vyas in 2009 showed temporal expression of rai1 in zebrafish embryos as early as 9 hpf. We hypothesize that there is maternal …

Development Of Non-Traditional Platinum Anticancer Agents: Trans-Platinum Planar Amine Compounds And Polynuclear Platinum Compounds, Daniel E. Lee

Theses and Dissertations

Development of Non-Traditional Platinum Anticancer Agents: trans-Platinum Planar Amine Compounds and Polynuclear Platinum Compounds

By Daniel E. Lee, Ph.D.

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University.

Virginia Commonwealth University, 2015

Major Director: Nicholas P Farrell, Ph.D., Professor, Department of Chemistry

Platinum anticancer compounds with cis geometry, similar to cisplatin, have been explored to circumvent the cisplatin resistance; however, they were not considered broadly active in cisplatin cells due to exhibiting similar or same cell death mechanism as cisplatin. Platinum compounds with trans geometry were less studied …

The Effect Of Statins On Il-33 Mediated Mast Cell Function, Marcela Taruselli

Theses and Dissertations

This study demonstrates original findings of statin effects on IL-33 stimulated mast cells. Statins are a class of drugs used to lower cholesterol production by targeting HMG CoA reductase. These commonly prescribed drugs have been shown to be immunomodulatory. In this study, we have found that pretreatment with statins has a variety of effects on IL-33 stimulated mast cells. Atorvastatin suppresses TNF and IL-6 production, while fluvastatin significantly enhances release of these proinflammatory cytokines in BMMCs. Although they have differing effects on cytokine production, both statins lowered ST2 expression on the cell surface, decreased cell viability, and enhanced expression of …

Interaction Between Atm Kinase And P53 In Determining Glioma Radiosensitivity, Syed F. Ahmad

Theses and Dissertations

Glioblastoma multiforme (GBM) is the most common primary brain tumor. Studies have shown that targeting the DNA damage response can sensitize cancer cells to DNA damaging agents. Ataxia telangiectasia mutated (ATM) is involved in signaling DNA double strand breaks. Our group has previously shown that ATM inhibitors (ATMi) sensitize GBM cells and tumors to ionizing radiation. This effect is greater when the tumor suppressor p53 is mutated.

The goals of this work include validation of a new ATM inhibitor, AZ32, and elucidation of how ATMi and p53 status interact to promote cell death after radiation. We propose that ATMi and …

High-Throughput Data Analysis: Application To Micronuclei Frequency And T-Cell Receptor Sequencing, Mateusz Makowski

Theses and Dissertations

The advent of high-throughput sequencing has brought about the creation of an unprecedented amount of research data. Analytical methodology has not been able to keep pace with the plethora of data being produced. Two assays, ImmunoSEQ and the cytokinesisblock micronucleus (CBMN), that both produce count data and have few methods available to analyze them are considered.

ImmunoSEQ is a sequencing assay that measures the beta T-cell receptor (TCR) repertoire. The ImmunoSEQ assay was used to describe the TCR repertoires of patients that have undergone hematopoietic stem cell transplantation (HSCT). Several different methods for spectratype analysis were extended to the TCR …

Characterizarion Of The Regulation And Function Of Neisseria Gonorrhoeae Tonb-Dependent Transporters: Tdfg, Tdfh And Tdfj, Sophonie Jean

Theses and Dissertations

The obligate human pathogen Neisseria gonorrhoeae successfully overcomes host strategies to limit essential nutrients, termed “nutritional immunity” by expression of TonB-dependent transporters (TdTs): outer membrane receptors that facilitate nutrient transport in an energy-dependent manner. N. gonorrhoeae encodes eight TdTs, five of which facilitate utilization of iron or iron-chelates from host derived proteins including transferrin, lactoferrin and hemoglobin, in addition to siderophores from neighboring bacteria. The transferrin utilization system was previously shown to be critical for establishing infection in human males; demonstrating the possible contributions of TdTs to gonococcal pathogenesis. As such, studies describing the biological function and contribution to pathogenesis …

Dysregulation Of Micrornas In Blood As Biomarkers For Diagnosing Prostate Cancer, Rhonda W. Daniel

Theses and Dissertations

Prostate cancer is the most common noncutaneous cancer among men, yet current diagnostic methods are insufficient and more reliable diagnostic markers need to be developed. The answer that can bridge this gap and enable more efficient diagnoses may lie in microRNAs. These small, single stranded RNA molecules impact protein expression at the translational level and regulate important cellular pathways. Dysregulation of these small RNA molecules can have tumorigenic effects on cells and lead to many types of cancers.

Currently the Prostate-Stimulating Antigen (PSA) is used as a diagnostic marker for prostate cancer. However, many factors can elevate PSA levels such …

A Systems Biology Approach To Detect Eqtls Associated With Mirna And Mrna Co-Expression Networks In The Nucleus Accumbens Of Chronic Alcoholic Patients, Mohammed Mamdani

Theses and Dissertations

Alcohol Dependence (AD) is a chronic substance use disorder with moderate heritability (60%). Linkage and genome-wide association studies (GWAS) have implicated a number of loci; however, the molecular mechanisms underlying AD are unclear. Advances in systems biology allow genome-wide expression data to be integrated with genetic data to detect expression quantitative trait loci (eQTL), polymorphisms that regulate gene expression levels, influence phenotypes and are significantly enriched among validated genetic signals for many commonly studied traits including AD.

We integrated genome-wide mRNA and miRNA expression data with genotypic data from the nucleus accumbens (NAc), a major addiction-related brain region, of 36 …

The Cytotoxic Effect Of The Bcl-2 Family Of Proteins In Breast Cancer Cells, Yamileth Chin

Theses and Dissertations

Breast cancer is the second leading cause of death amongst women ages 20 to 59. Despite advancements in cancer therapies, more research is necessary to improve the diagnoses and treatment of several types of breast cancer. Paclitaxel (Taxol) is a commonly utilized anti-cancer drug for various types of solid tumors. However, the molecular mechanism utilized by paclitaxel to induce cell death is still elusive. Previous studies in our laboratory have shown that the pro-apoptotic BCL-2 family protein, BAK (BCL-2 homologous antagonist/killer) plays an important role in paclitaxel-induced cell death. In untreated breast cancer cells, BAK is associated with the anti-apoptotic …

Comparison Of Two Different Sprint Interval Training Work-To-Rest Ratios On Acute Metabolic And Inflammatory Responses, Christopher R. Harnish

Theses and Dissertations

High intensity exercise is believed to yield greater results on health and human performance than moderate intensity exercise. Extensive research indicates that not only do high-intensity interval training (HIT) and sprint interval training (SIT) produce significant improvements in cardiovascular fitness and disease, they may be more effective at improving long-term metabolic function, including insulin sensitivity (Si), by producing more mitochondria. Moreover, compliance rates for HIT and SIT participation are reported to be the same or better than traditional moderate intensity exercise. Because lack of time is often cited as major hindrance to exercise participation, SIT is also seen as a …

Using Structural Analysis To Investigate The Function Of Suppressor Of Ikk-Epsilon (Sike), Sean W. Mckinley

Theses and Dissertations

The innate immune system provides the body’s first line of defense against pathogenic challenge through pathogen recognition and initiation of the immune response. Among the various cellular mechanisms of pathogen recognition in mammals, Toll-like receptor 3 (TLR3) recognizes viral dsRNA. Stimulation of TLR3 signaling pathway leads to transcription of pro-inflammatory cytokines and type-1 Interferons. Suppressor of IKKε (SIKE) interacts with two kinases in the signaling pathway, IKKε and TANK binding kinase 1 (TBK1), inhibiting the transcription of type I interferons. Recently, the Bell Laboratory discovered that SIKE blocks TBK1-mediated activation of type I interferons by acting as a high affinity, …

Isolation And Characterization Of Multipotent Lung Stem Cells From P53 Mutant Mice Models, Venkat Sundar Gadepalli

Theses and Dissertations

Recent advances in understanding lung biology have shown evidence for the existence of resident lung stem cells. Independent studies in identifying and characterizing these somatic lung stem cells have shown the potential role of these cells in lung repair and regeneration. Understanding the functional characteristics of these tissue resident stem/progenitor cells has gained much importance with increasing evidence of cancer stem cells, cells in a tumor tissue with stem cell characteristics. Lung cancer is most commonly characterized by loss of p53 function which results in uncontrolled cell divisions. Incidence of p53 point mutations is highest in lung cancer, with a …

Sildenafil And Celecoxib Interact To Kill Breast Cancer Cells, Brittany Binion

Theses and Dissertations

Breast cancer is the second most commonly diagnosed cancer among American women and is responsible for the second highest number of cancer-related deaths. Targeted therapeutic agents sildenafil, a phosphodiesterase type 5 inhibitor, and celecoxib, a cyclooxygenase-2 inhibitor, have been used individually in conjunction with other chemotherapeutic agents to enhance cell killing in a variety of cancers. Sildenafil when combined with traditional chemotherapeutic drugs, such as the taxanes and anthracyclines, or celecoxib combined with traditional hormone therapies have been used to increase cytotoxicity and cell killing. The data presented here demonstrates that the novel combination of sildenafil and celecoxib work together …