Medicine and Health Sciences Commons^™

The Role Of Dual Specificity Phosphatase -11 In Innate And Adaptive Immune Responses, Kalyan Chakravarthy Nallaparaju

Dissertations and Theses (Open Access)

THE ROLE OF DUAL SPECIFICITY PHOSPHATASE -11 IN INNATE AND ADAPTIVE IMMUNE RESPONSES

Kalyan Chakravarthy Nallaparaju, M.S.

Supervisory Professor: Chen Dong, Ph.D.

Dual-specificity phosphatases (DUSPs) constitute a subfamily of protein tyrosine phosphatases characterized by their ability to dephosphorylate both phosphotyrosine and phosphoserine/phosphothreonine residues within a substrate, typically among members of the MAP kinase family. DUSPs have been shown to play a critical role in the regulation of various cellular processes including signal transduction, cell cycle regulation and cellular proliferation via modulation of MAP kinase activities. Also, many members of this family have been demonstrated to be potent immune regulators. …

Nprl2/Tusc4 Functions As A Tumor Suppressor By Regulating Brca1’S Stability Via The E3 Ubiquitination Pathway, Yang Peng

Dissertations and Theses (Open Access)

Expression of the tumor suppressor protein BRCA1 is frequently lost in breast cancer patients, and the loss of its expression is associated with disruption of various critical functions in cells and cancer development. In the present study, we demonstrate through microarray analysis that cells with tumor suppressor candidate 4 (NPRL2/TUSC4) knockdown show critical changes to cell cycle, cell death pathways and a global impact on cancer development. More importantly, we observed a clear cluster pattern of NPRL2/TUSC4-knockdown gene profiles with established homologous recombination (HR) repair defect signature. Additionally, NPRL2/TUSC4 protein physically interacts with the E3 ligase HERC2 and prevents ubiquitin …

Epidermal Growth Factor Receptor Induces Fyn Expression Via Up-Regulation Of P47phox In Glioblastoma Multiforme, Blake P. Johnson

Dissertations and Theses (Open Access)

Src family kinases (SFKs) are commonly over-expressed and/or activated in glioblastoma multiforme (GBM), where they serve as key mediators of GBM cell proliferation, survival, invasion and angiogenesis. Mechanisms of allosteric SFK activation are well described; however, the SFK Fyn is commonly up-regulated at the mRNA level in multiple human cancers, including GBM, where the mode of increased expression is poorly understood. Since activating mutations in the epidermal growth factor receptor (EGFR) are commonly occurring in GBM, we examined whether EGFR could induce Fyn expression. Here, we found that wild-type EGFR, and to a greater extent hyper-activating EGFR mutants, EGFRΔIII and …

Targeting Cox-2 And Rank In Aggressive Breast Cancers: Inflammatory Breast Cancer And Triple-Negative Breast Cancer, Monica Elizabeth Reyes

Dissertations and Theses (Open Access)

Inflammatory breast cancer (IBC) and triple-negative breast cancer (TNBC) are two highly aggressive breast cancer subtypes associated with a poor outcome. Despite sensitivity to current treatment, these breast cancers subtypes have a high recurrence rate and proclivity to metastasize early. The aggressiveness of IBC and TNBC have been linked to CSCs and epithelial to mesenchymal transition (EMT), which are critical features of breast cancer progression and metastasis. The clinical challenge faced in the treatment of IBC and TNBC is finding a treatment strategy to target the cancer stem-like (CSC) population to block metastasis. Cyclooxygenase-2 (COX-2) and receptor activator of nuclear …

Dual Assembly Nanoparticles Achieve Sustained Silencing Of Znf304: A Novel Transcription Factor For Β1 Integrin, Burcu Aslan

Dissertations and Theses (Open Access)

Ovarian cancer (OC) is a highly metastatic disease, but no effective strategies to this process currently are known. Here, an integrated computational analysis of The Cancer Genome Atlas ovarian cancer dataset coupled with experimental validation identified a novel zinc finger transcriptional factor 304 (ZNF304) as one of the key factors for ovarian cancer metastasis. High tumoral ZNF304 expression was associated with poor overall survival in ovarian cancer patients. Through reverse phase protein array analysis, we demonstrated that ZNF304 promotes multiple proto-oncogenic pathways important for cell survival, migration, and invasion. ZNF304 transcriptionally regulates β1 integrin, which subsequently regulates Src/focal adhesion kinase …

Targeting Cox-2 And Rank In Aggressive Breast Cancers: Inflammatory Breast Cancer And Triple-Negative Breast Cancer, Monica E. Reyes

Dissertations and Theses (Open Access)

Inflammatory breast cancer (IBC) and triple-negative breast cancer (TNBC) are two highly aggressive breast cancer subtypes associated with a poor outcome. Despite sensitivity to current treatment, these breast cancers subtypes have a high recurrence rate and proclivity to metastasize early. The aggressiveness of IBC and TNBC have been linked to CSCs and epithelial to mesenchymal transition (EMT), which are critical features of breast cancer progression and metastasis. The clinical challenge faced in the treatment of IBC and TNBC is finding a treatment strategy to target the cancer stem-like (CSC) population to block metastasis. Cyclooxygenase-2 (COX-2) and receptor activator of nuclear …

Selective Elimination Of Malignant Melanoma Using The Novel Anti-Tumor Agents, Osw-1 And Peitc, Kausar Begam Riaz Ahmed

Dissertations and Theses (Open Access)

Metastatic melanoma is amongst the most refractory of cancers. Drug resistance and lack of therapeutic selectivity are two main challenges to successful melanoma therapy. Herein, we investigated the mechanims of anticancer activity and therapeutic selectivity of two novel agents, 3β, 16β, 17α-trihydroxycholest-5-en-22-one 16-O-[2-O-4-methoxybenzoyl-β-D-xylopyranosyl]- [1→3]-2-O-acetyl-α-l-arabinopyranoside (OSW-1) and β-Phenylethyl Isothiocyanate (PEITC) in melanoma.

OSW-1 inhibited melanoma cell viability at nanomolar concentrations with minimal toxicity to normal melanocytes. Mechanistic studies revealed that OSW-1 suppressed Disialoganglioside 3 Synthase (GD3S) gene expression in melanoma cells, leading to inhibition of gangliosides GD3 and GD2. GD3 is an abundantly expressed melanoma …

Masculinity, Male Empowerment, And Hiv/Aids Risk In Caprivi, Namibia, Mark Perry

Dissertations and Theses (Open Access)

Namibia has a generalized HIV epidemic, with 13% of adults being infected. Its East Caprivi Region has the highest prenatal HIV prevalence in the country, 21%, among girls and women aged 15-24 years. In recent years, researchers have pointed to men who express their masculinity through high-risk sex as driving the epidemic in East Caprivi. This exploratory study examined the role that men and their masculinity concepts played in transmission, how those concepts were evolving over time, what was influencing the change, and in which directions. Employing grounded theory methods and guided by Robert Connell's theoretical framework on masculinities, the …

Association Of Cardiorespiratory Fitness And Adiposity With Inflammatory Biomarkers In Young Adults, Eunduck Park

Dissertations and Theses (Open Access)

Background: Low grade systemic inflammation plays a key role in atherosclerosis, and C-reactive protein (hs-CRP), interleukin-6 (IL-6), and tumor necrosis factor- alpha (TNF -a), markers of systemic inflammation, are associated with cardiovascular events and adiposity. Cardiorespiratory fitness has shown health benefits by reducing circulating levels of inflammatory markers. However, it remains uncertain whether the negative association between cardiorespiratory fitness and inflammatory biomarkers is due to cardiorespiratory fitness itself or results from lower levels of adiposity. Moreover, the evidence examining the interaction between cardiorespiratory fitness and adiposity in inflammation in young adults is lacking.

Purpose: The aims of this study were …

Strategies To Sensitize Bladder Cancer Cells To Small Molecule Inhibitors Targeting The Pi3k Pathway, Giovanni Nitti

Dissertations and Theses (Open Access)

After many years of cancer research, it is well accepted by the scientific community that the future cure for this disease lies in a personalized therapeutic approach. Anticipating therapeutic outcome based on the genetic signature of a tumor has become the new paradigm. The PI3K pathway represents an ideal target for bladder cancer, as many of the key proteins of this pathway are altered or mutated in this particular type of cancer. Several small molecule inhibitors have been developed to target this pathway, but their efficacy has been shown to be heterogeneous among different cell lines and mostly cytostatic but …

Mapping The Human Vasculature By In Vivo Phage Display, Julianna Bronk

Dissertations and Theses (Open Access)

In vivo phage display screenings by intravenous injection of a random phage-displayed peptide library allow for the selection of peptides that localize to specific vascular beds. At the University of Texas MD Anderson Cancer Center, we have had the opportunity to perform phage display screenings in cancer patients in order to select for cancer specific targets directly in humans. These targets serve to define biochemical diversity of endothelial cell surfaces and can be validated and explored towards the design of vascular-targeted pharmacology. In the most recent patient screen, samples were recovered from hepatocellular carcinoma (HCC) as well as 26 additional …

Pi3k- And Mtor-Dependent Mechanisms Of Lapatinib Resistance And Resulting Therapeutic Opportunities, Samuel Brady

Dissertations and Theses (Open Access)

Breast cancers with HER2 amplification represent 20-25% of breast cancer cases and are frequently responsive to the HER2 kinase inhibitor lapatinib, but generally for only short duration. We aimed to understand how breast cancers with HER2 amplification become resistant to lapatinib, in order to identify potential therapies that can overcome lapatinib resistance. To establish lapatinib resistance models we treated three HER2+ breast cancer cell lines with lapatinib for several months until they became lapatinib-resistant. We then compared lapatinib-sensitive (parental) cells with their lapatinib-resistant (LapR) counterparts to identify changes conferring lapatinib resistance. We found that activation of PI3K, specifically the p110α …

Cd56-Specific T Cells: Using Genetically Engineered T Cells To Redirect Specificity To A T Cell Expressed Antigen, Denise L. Crossland

Dissertations and Theses (Open Access)

The CD56 antigen is expressed on several deadly malignancies currently lacking long-term efficacious therapies. Chimeric antigen receptor (CAR) based immunotherapies have shown both safety and efficacy and even a curative ability in clinical trials, laying the foundation for applying CARs to new targets. Using T cells to target a T cell expressed antigen, such as CD56, seems counterintuitive in that the T cells would be susceptible to self-targeting a.k.a. fratricide. However, we expand CD56-specific CAR⁺ T cells that co-express the CD56 antigen. Since other CARs targeting T cell expressed antigens are hypothesized to be undergoing fratricide, such as the …

Characterization Of The Vascular Pathology In The Acta2 R258c Mouse Model And Cerebrovascular Characterization Of The Acta2 Null Mouse, Carlos A. Villamizar

Dissertations and Theses (Open Access)

Mutations in ACTA2, the gene encoding for smooth muscle α-actin, predispose patients to a wide range of vascular diseases and is most commonly associated with thoracic aortic aneurysms (TAAD) and dissections (TAAD) and strokes. TAAD in patients is characterized by aortic media degeneration and loss in contractile force generation followed by aortic enlargement and subsequent rupture. Most stroke cases associated with ACTA2 are described as moyamoya-like cerebrovascular incidents characterized by distal occlusion of the internal carotid artery, stenosis of arteries in the Circle of Willis, and straightening of cerebral arteries. Patient samples are scarcely available for analysis, and the few …

Role Of The Ang-Tie2 Pathway In The Invasive Recurrence Of Gbm Following Anti-Vegf Therapy, Nahir Cortes Santiago

Dissertations and Theses (Open Access)

Strong pre-clinical and clinical data supporting the effectiveness of bevacizumab, a humanized monoclonal anti-VEGF antibody, for the treatment of gliomas led to its accelerated approval for the treatment of patients with recurrent glioma. However, despite strong anti-tumor effects, upon treatment with bevacizumab, patients will invariably recur with a tumor characterized by enhanced invasiveness and resistance to therapy. This study aims to elucidate the mechanisms leading to this enhanced malignancy with the hope of uncovering new potential therapeutic targets for combined treatment. Using tissue sections from U87-derived glioma bearing mice treated with or without aflibercept (another anti-VEGF antibody) we have gathered …

The Apical Polarity Complex Protein, Pals1, Regulates Cell Fate In The Development Of Cerebellum And Neocortex, Jun Young Park

Dissertations and Theses (Open Access)

Through their biased localization and function within the cell, polarity complex proteins are necessary to establish the cellular asymmetry required for tissue organization. Well-characterized germinal zones, mitogenic signals, and cell types make the cerebellum and neocortex excellent models to address the critical function of polarity complex proteins in the generation and organization of neural tissues. Here we report a focal distribution of Pals1, a central component of the apical complex, in progenitors. Our genetic analyses revealed that Pals1 deletion in the brain developed a remarkably undersized and disrupted layer structure of cerebral cortex and cerebellum. Furthermore we demonstrated that Pals1 …

The Kras/Mapk Pathway And Ligand Independent Activation Of Erα: Implications For The Treatment Of Endometrial Cancer, Kari Ring

Dissertations and Theses (Open Access)

Hormonal therapy remains a first line option for the treatment of recurrent endometrial cancer (EC), however, many tumors demonstrate de novo or acquired resistance. Member kinases of the PI3K/AKT and Ras/MAPK pathways activate estrogen receptor α (ERα) independent of estrogen, however, few studies have evaluated the role of the Ras/MAPK pathway in predicting response to hormonal therapy in EC. The aims of this project were to evaluate the role of ligand independent activation of ERα in EC and to explore therapeutic implications for the treatment of recurrent EC.

A xenograft model for recurrent EC was used to evaluate the effect …

Role Of Macrophages In Adaptive Resistance To Anti-Vegf Therapy, Heather Dalton

Dissertations and Theses (Open Access)

Background: The clinical implementation of therapies targeting the VEGF pathway in cancer has been limited by acquired resistance; yet, the mechanisms by which this occurs is unclear. We investigated the role of macrophages in the development of acquired resistance to anti-VEGF antibody (AVA) therapy.

Materials and Methods: We first established a murine ovarian cancer model of resistance to anti-VEGF therapy. Using this model we investigated changes in macrophage infiltration during AVA sensitive and resistant phases. We also investigated the in vivo effects of macrophage depletion at the emergence of anti-VEGF resistance and in upfront combination with AVA therapy. In vitro …

Volumetric Scintillation Dosimetry For Scanned Proton Beams, Daniel G. Robertson

Dissertations and Theses (Open Access)

Scanned beam proton therapy is a promising cancer treatment modality which is becoming more widely available with the increasing number of proton radiotherapy centers. Scanned proton beams can produce complex 3D dose distributions, presenting a challenge for adequate quality assurance testing. Because each scanned beam dose measurement requires the delivery of the entire field, multiple measurements can be time consuming. These quality assurance challenges limit the number of patients who can be treated with this modality. The overall objective of this project is to increase the safety and availability of complex proton therapy treatments by developing a fast volumetric scintillation …

Novel Serum Biomarkers For Lung Cancer Early Diagnosis And Clinical Outcome, Fanmao Zhang

Dissertations and Theses (Open Access)

The five-year survival rate for all stages of lung cancer combined is only 17%, which has changed little over the past 40 years. Despite the tremendous efforts made, serum biomarkers with clinical utility for lung cancer early detection and clinical outcome prediction are still lacking. Metabolic alterations have been recognized as an emerging hallmark of cancer. We aimed to investigate the metabolic changes associated with lung cancer and to identify novel clinically applicable serum biomarkers for lung cancer early diagnosis and clinical outcome.

Serum metabolites are potential biomarkers for lung cancer early detection. We first performed global metabolomic profiling followed …

Multiple Myeloma And Its Treatment Alter Peripheral Nervous System Structure And Function, Alyssa K. Kosturakis

Dissertations and Theses (Open Access)

MULTIPLE MYELOMA AND ITS TREATMENT ALTER PERIPHERAL NERVOUS SYSTEM STRUCTURE AND FUNCTION

Alyssa Katarina Kosturakis, BA

Supervisory Professor: Patrick M. Dougherty, PhD

Peripheral neuropathy is among the most deleterious side effects of frontline chemotherapeutics used to treat prevalent cancers. Chemotherapy-induced peripheral neuropathy (CIPN) refers to the collection of symptoms (e.g. pain, paresthesias and dysesthesias) that develop in distal, glabrous (non-hairy) skin of 20 to 100% of patients treated with chemotherapy. Peripheral neuropathy negatively impacts quality of life in cancer patients and survivors, is refractory to treatment, and is the impetus for dose-reduction and/or cessation of chemotherapy, thereby limiting treatment. Proteasome …

Notch Signaling Inhibited By Ikaros1 In Human T-Cell Acute Lymphoblastic Leukemia, Camille W. Graham

Dissertations and Theses (Open Access)

The highly conserved Notch signaling pathway regulates cell growth, differentiation, survival and apoptosis. In hematopoiesis, Notch signaling drives commitment to the T-cell fate and promotes differentiation, T-cell receptor signaling and immune function. In T-cells, Notch signaling is oncogenic when constitutively active, promoting proliferation and survival while inhibiting differentiation. The majority of patients with T-cell acute lymphoblastic leukemia (TALL) have activating Notch mutations. Similarly, Notch activation is present in more than 75% of murine T-ALL models. In murine T-ALL, loss of Ikaros, a zinc finger transcriptional regulator, leads to disrupted differentiation and also cooperates with activated Notch signaling to promote T-ALL. …

Regulators Of Bacterial Cell Division: Investigations Of Min Oscillation And Ftsa Activity, Jennifer R. Herricks

Dissertations and Theses (Open Access)

Cytokinesis is a fundamental process that is essential for bacterial proliferation. The cytokinetic machinery in bacteria is termed the “divisome”. The divisome is a complex of proteins that forms a ring at midcell over dividing nucleoids. In order for daughter cells to form, the divisome must constrict. As constriction occurs, two new cell poles are formed, one for each daughter cell. The first step in divisome formation is the assembly of FtsZ into a Z ring. The work presented in this dissertation focuses on two proteins that regulate the Z ring: MinD, which is a part of the Min system …

Potential Roles Of Peroxidases In Caenorhabditis Elegans Innate Immunity, George R. Tiller, George R. Tiller

Dissertations and Theses (Open Access)

The production of ROS (reactive oxygen species) in response to pathogen detection is a rapid, nonspecific response that is evolutionarily conserved from nematodes to humans. ROS serve as direct and indirect effectors of innate and adaptive immunity. In Caenorhabditis elegans, a ROS burst is observed during infection and is mediated by the dual oxidase BLI-3, which produces H₂O₂. RNAi (RNA interference) to reduce the amount of BLI-3 results in a significant increase in susceptibility to pathogens, suggesting BLI-3 has a role in the immune response. However, H₂O₂ by itself is not a …

Genetic Predictors Of Metabolic Side Effects Of Diuretic Therapy, Jorge L. Del Aguila

Dissertations and Theses (Open Access)

Thiazide diuretics are a recommended first-line monotherapy for hypertension (i.e.SBP>140 mmHg or DBP>90 mmHg). Even so, diuretics are associated with adverse metabolic side effects, such as hyperlipidemia, hyperglycemia and hypokalemia which increase the risk of developing type II diabetes. This thesis used three analytical strategies to identify and quantify genetic factors that contribute to the development of adverse metabolic effects due to thiazide diuretic treatment. I performed a genome-wide association study (GWAS) and meta-analysis of the change in fasting plasma glucose and triglycerides in response to HCTZ from two different clinical trials: the Pharmacogenomic Evaluation of Antihypertensive Responses …

Targeting The Redox System To Overcome Mechanisms Of Drug Resistance In Chronic Lymphocytic Leukemia, Marcia A. Ogasawara

Dissertations and Theses (Open Access)

Chronic Lymphocytic Leukemia (CLL) is the most common form of leukemia diagnosed in Western countries and is characterized by clonal expansion of B cells. The clinical course of CLL is diverse and nearly 50% of patients present with chromosomal abnormalities. Deletion of the short arm on chromosome 17 (del17p) occurs in 5-7% of cases and presents with the shortest median survival time and often respond poorly to therapy. The tumor suppressor gene, TP53 is located on this region and it is well established that the p53 protein regulates multiple functions including: mitochondria biogenesis, response to DNA damage and redox balance. …

Development Of A New Independent Monte Carlo Dose Calculation Quality Assurance Audit To Ol For Clinical Trials, Austin M. Faught

Dissertations and Theses (Open Access)

Introduction: Commercially available treatment planning systems (TPS) may use a number of different radiation dose calculation algorithms during the planning process. The Radiological Physics Center (RPC), tasked with ensuring clinically comparable and consistent dose delivery amongst institutions participating in NCI funded multi-institutional clinical trials, has traditionally relied upon measurements to achieve this objective. As a supplement to the tools used by the RPC, an independent dose calculation tool is needed to determine patient dose distributions in three dimensions so as to act as a quality assurance tool for the dose calculations.

Methods: Multiple source models representing the output of Elekta …

The Role Of The C5a Receptor In Host Defense Against Listeria Monocytogenes, Daniel Calame

Dissertations and Theses (Open Access)

Listeria monocytogenes (Lm) is a major cause of mortality resulting from food poisoning in the United States. While the complement component C5 is known to be protective in listeriosis, it is unknown how its cleavage fragment C5a participates. Here we show in a model of systemic Lm infection that the C5a receptor is essential for host defense. C5aR-/- mice have reduced survival and increased bacterial burden in the liver and spleen in comparison to WT mice. Surprisingly, C5aR-/- mice also have a dramatic reduction in splenocyte numbers resulting from elevated cell death as indicated by TUNEL staining and caspase 3 …

The Oncogenic Map Kinase Signaling Pathway Modulates Mhc-I Surface Expression In Melanoma, Sherille Denae Bradley

Dissertations and Theses (Open Access)

The mitogen-activated protein kinase (MAPK) pathway is a cascade of serine-threonine kinases involved in cell growth, proliferation, and apoptosis; it is one of the most well-known pathways associated with melanoma progression. The MAPK pathway is constitutively activated in melanomas due to mutations in the signaling components, particularly the proto-oncogene BRAF ^V600E that accounts for (40-50%) of these cases. Metastatic melanoma is one of the deadliest and most aggressive forms of cancer, with a 3-year survival rate of less than 15%. Immunotherapies that utilize cytotoxic T lymphocytes (CTLs) have proven to be very effective at inducing regressions of large, bulky tumors, …

Roles For B-Raf Kinase In The Specific Regulation Of Α4Β1 Integrin In T Cells, Wells S. Brown

Dissertations and Theses (Open Access)

The regulation of integrin-mediated adhesion is of vital importance to adaptive and innate immunity. Integrins are versatile proteins and mediate T cell migration and trafficking by binding to ECM or other cells, as well as initiating intracellular signaling cascades promoting survival or activation. The mitogen activated-protein kinase (MAPK) pathway is known to be downstream from integrins and regulate survival, differentiation, and motility. However, secondary roles for canonical MAPK pathway members are being discovered. We show chemical inhibition of RAF by Sorafenib or shRNA-mediated knockdown of B-Raf reduces T cell resistance to shear stress to α4β1 integrin ligands vascular cell adhesion …