Life Sciences Commons^™

Risk-Factor Induced Changes In The Breast Microenvironment Facilitate Inflammatory Breast Cancer Progression And Lymphovascular Invasion, Wintana Balema, Wintana Balema

Dissertations & Theses (Open Access)

Inflammatory breast cancer (IBC) is a rapidly progressing, rare and highly lethal form of breast cancer. IBC is a clinical diagnosis, requiring >1/3 involvement on the affected breast and/or skin by erythema, and disease onset of < 6 months. The clinical symptoms of IBC vary in severity and presentation, these include redness, warmth, skin thickening and bruised or pink/purple discoloration appearance and skin changes such as peau d’orange. These skin symptoms are not attributed to inflammation, rather IBC is characterized by florid lymphovascular tumor emboli clogging dermal lymphatics. This leads to “classic” symptoms of breast swelling and skin edema or discoloration. To date, unique genomic drivers which differentiate IBC from non-IBC invasive breast cancers have not been identified highlighting a role for the microenvironment. Several epidemiological studies have unveiled subtype-specific risk factors associated with IBC that are known to alter the microenvironment. Obesity is an established risk factor for all subtypes of IBC. Never-breastfeeding increases risk for developing the most aggressive, triple-negative IBC. Further, never breastfeeding is associated with later clinical stage and worse outcomes. We worked to model these overlapping risk factors to understand microenvironment changes that may lead to the lymphatic change’s indicative of IBC.

First, we investigated the association of a “classic” triad of clinical IBC signs with overall survival among patients to demonstrate the most overt clinical findings of lymphatic involvement were impacting prognosis. We evaluated a triad of IBC signs, including swollen involved breast, nipple change, and diffuse skin change, using breast medical photographs from patients enrolled on a prospective IBC registry. We reported that the …

Individual Differences In Lpp Amplitude And Theta Power Predict Cue-Induced Eating During A Cued Food Delivery Task, Kyla Gibney

Dissertations & Theses (Open Access)

Due to individual differences in the brain’s reward system, some individuals are more vulnerable than others to maladaptive, reward-seeking behaviors, such as substance use or compulsive eating. A body of research has demonstrated that individuals who attribute higher levels of incentive salience to reward-associated cues than to pleasant images (termed “C>P group” throughout) are more vulnerable to compulsive eating than those who attribute higher incentive salience to pleasant images than reward- associated cues (P>C group). Meanwhile, a separate body of research has demonstrated that cognitive control also regulates eating by enabling top-down attentional control. This dissertation aims to …

Med12 Is A Critical Regulator Of Neural Crest Lineage And Nervous System Myelination, Fatma Betul Aksoy Yasar

Dissertations & Theses (Open Access)

The Mediator complex (MED) is a multi-subunit protein complex integral to the eukaryotic transcription machinery. MED12 is a Cdk8- regulatory kinase module subunit directly implicated in human disease and is genetically altered in neurological disease and cancer. Numerous attempts at generating an in vivo system to study the role of Med12 failed due to embryonic lethality associated with germline or developmental disruption of Med12 gene. To understand the cellular and molecular processes associated with its role in disease, we generated multiple mouse models with targeted depletion of MED12 in distinct cellular lineages. Our genetically engineered models with induced and conditional …

Ankyrin Dependent Mitochondrial Function And Bioenergetics In The Heart, Janani Subramaniam, Janani Subramaniam

Dissertations & Theses (Open Access)

ANK2 mutations in patients are associated with numerous arrhythmias, cardiomyopathies, and other heart defects. In the heart, AnkB, the protein encoded by ANK2, clusters relevant ion channels and cell adhesion molecules in several important domains; however, its role at Mitochondria Associated ER/SR Membranes (MAMs) has yet to be investigated. MAMs are crucial to mitochondrial function and metabolism and are signaling hubs implicated in various cardiac pathologies. Among several functions, these sites mediate the direct transfer of calcium from the ER/SR to the mitochondria to modulate ATP synthesis. Given that mitochondrial function and energy production are paramount to cardiovascular heath, …

Yap And Taz Are Required For Neural Crest-Derived Cardiovascular Development, Shannon Erhardt

Dissertations & Theses (Open Access)

Congenital heart defects (CHDs) are the most common human birth defect, occurring in ~1/100 newborns, and are a leading cause of early infant death. Cardiac neural crest cells (NCCs) are a migratory and multipotent cell population known to aid in the development of the cardiac outflow tract (OFT), valves, and interventricular septum, during embryogenesis. Yap and Taz are downstream effectors of the fundamental Hippo signaling pathway and are vital for proper organ and tissue development, yet their role in neural crest (NC)-derived heart formation is still largely unknown. We generated Yap and Taz conditional knockout (CKO) mice using a Cre-lox …

The Role Of The Hypoxia-Inducible Factor 2 In Pancreatic Cancer: Mechanisms Of Tumor Immunosuppression And Intestinal Radioprotection, Carolina Garcia Garcia

Dissertations & Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with dismal prognosis. The only curative option for patients is surgery, but over 80% of patients are not surgical candidates. Unfortunately, PDAC is resistant to the three remaining options. PDAC is characterized by a profoundly hypoxic and immunosuppressive stroma, which contributes to its therapeutic recalcitrance. Alpha-smooth muscle actin+ (αSMA+) cancer-associated fibroblasts (CAFs) are the most abundant stromal component, as well as mediators of stromal deposition. The hypoxia-inducible factors (HIF1 and HIF2) coordinate responses to hypoxia, yet, despite their known association to poor patient outcomes, their functions within the PDAC tumor microenvironment (TME) …

Roles Of Oxidative Stress And Dna Methylation In Cigarette Smoking-Induced Accelerated Acute Myeloid Leukemia Progression, Mary Figueroa

Dissertations & Theses (Open Access)

Acute myeloid leukemia (AML) is a commonly diagnosed cancer in smokers. When current or former smokers have AML, they have worse survival compared to never smoking patients. This has been observed clinically for decades, but then it is unknown how smoking leads to worsened AML survival. Smoking causes oxidative stress and altered DNA methylation that persists for decades in peripheral blood mononuclear cells, but these changes from smoking have not been evaluated in the context of AML. We hypothesize that smoking-induced molecular changes, including altered DNA methylation associated with poor AML prognosis, promote AML. We developed a novel model to …

A Microfluidics-Based Approach For Isolation Of Antigen-Specific Cd8+ T Cells, Meredith Frank

Dissertations & Theses (Open Access)

Cancer is a global epidemic: there are predicted to be 200 million new cases this year alone. Almost a quarter of all cancer-related deaths are caused by lung cancer, for which 5-year survival rates are just above 20%. 85% of lung cancer diagnoses are classified as non-small cell lung cancer (NSCLC) for which 5-year survival rates in metastatic disease are less than 10%. Early detection and targeted therapies have improved prognoses, yet relapse is still common among patients.

Immunotherapies that leverage tumor-specific CD8⁺ cytotoxic T cells have shown great promise for the treatment of NSCLC. However, although highly promising, …

The Novel Role Of Dnmbp In Kidney Development, Brandy Walker

Dissertations & Theses (Open Access)

Congenital anomalies of the kidney and urinary tract (CAKUT) accounts for nearly one-fourth of all birth defects and more than 40% of pediatric end-stage renal disease, yet only 10-20% of CAKUT cases have a known monogenetic cause. Human kidneys are composed of up to a million epithelial tubules called nephrons. Disruption of nephron development is one of the many congenital anomalies that cause CAKUT, often resulting in chronic or end-stage renal disease which requires transplant. During nephron epithelialization, the formation of stable cadherin-mediated adhesion junctions is essential for maintaining cell-cell contacts. To understand the cell behaviors underlying abnormalities in renal …

Unraveling The Effects Of Aerobic Exercise And Erk5 Signaling In The Solid Tumor Microenvironment Using Murine Models, Hannah Savage

Dissertations & Theses (Open Access)

Solid tumors are comprised of multiple cell types which communicate and work together to promote tumor progression. Advances in the treatment of solid tumors have armed clinicians with more efficacious pharmacologic agents and combinations. However, a focus on drug adjuvants in the treatment of solid cancer has left gaps in knowledge regarding non-pharmacologic treatment adjuvants, like aerobic exercise. The current dissertation investigates pharmacologic and non-pharmacologic based approaches to remodel the solid tumor microenvironment landscape and alter therapeutic efficacy. We disassemble compartments of the tumor microenvironment, including tumor vasculature and immune infiltrate, using mouse models and single cell techniques, to elucidate …

Development Of Graphical Models And Statistical Physics Motivated Approaches To Genomic Investigations, Yashwanth Lagisetty

Dissertations & Theses (Open Access)

Identifying genes involved in disease pathology has been a goal of genomic research since the early days of the field. However, as technology improves and the body of research grows, we are faced with more questions than answers. Among these is the pressing matter of our incomplete understanding of the genetic underpinnings of complex diseases. Many hypotheses offer explanations as to why direct and independent analyses of variants, as done in genome-wide association studies (GWAS), may not fully elucidate disease genetics. These range from pointing out flaws in statistical testing to invoking the complex dynamics of epigenetic processes. In the …

Innate Lymphoid Cell Characterization And Ilc2s In Neuroinflammation In Aging And Sex Differences, Alexis Mobley, Alexis S. Mobley

Dissertations & Theses (Open Access)

Aging affects immunologic responses by a global immune system suppression, including dysregulation of cytokine mediators, leading to increased inflammation throughout all systems, termed inflammaging. However, understanding healthy aging mechanisms can bypass this effect. Inflammaging also leads to poor outcomes during brain injury, making immune-targeting therapeutics tantamount to overall brain health and longevity. Moreover, sex affects disease etiology and severity through hormonal and chromosomal sex, as the X chromosome contains most immunology-based genes. Androgens have a generally suppressive effect on the immune system. Additionally, when immune responses are mounted, males are better at CD4+ T cell type (Th1) responses, while females …

Novel Regulators Of Cellular Secretion Alter The Tumor Microenvironment To Drive Metastasis, Rakhee Bajaj

Dissertations & Theses (Open Access)

Lung cancer is a highly aggressive disease responsible for ~25% of all cancer-related deaths, due in part to its proclivity to metastasize. Treating metastasis holds potential for improving patient survival but requires a deeper investigation into the underlying mechanisms. Some of these processes that can regulate metastasis are: (1) Oncogenic targets of epithelial micro-RNAs (miRNAs) are epigenetically de-repressed upon loss of the miRNAs during epithelial-to-mesenchymal transition (EMT) and in cancer. EMT confers plasticity and fitness to cancer cells promoting their survival through the metastatic cascade. This cascade and EMT are initiated by loss of the miRNA200 family (miR-200) and the …

Parental Stress In Tuberous Sclerosis Complex, Jenny Do

Dissertations & Theses (Open Access)

Tuberous Sclerosis Complex (TSC) is a multi-systemic genetic disorder with great clinical variability. As the needs of one child with TSC may vastly differ from another, parenting demands may similarly differ. Characterizing parental stress, or emotional maladaptation arising from parenting duties, can enable healthcare providers to assist parents of children most efficiently with TSC-related symptoms and improve both parent and child health outcomes. This study surveyed 269 parents of children (aged 0-12 years) with TSC and received the following information: children’s TSC clinical features, parent demographics, and a Parent Stress Index (PSI) score. Parents reported higher stress levels for children …

Prenatal Testing Decisions And Motivations In Pregnancies Conceived Via In Vitro Fertilization, Michelle Appel

Dissertations & Theses (Open Access)

Currently, there is limited information about how conceiving through in vitro fertilization (IVF) and preimplantation genetic testing for aneuploidy (PGT-A) impact the decisions individuals make about prenatal genetic testing. This quantitative study aimed to examine the prenatal testing decisions made by pregnant individuals who conceived via IVF as well as to compare the prenatal testing decisions and motivations between those who had PGT-A and those who did not. An anonymous survey was distributed through online support forums and in clinical settings to eligible individuals. Overall, 230 complete responses were collected with 203 participants far enough along in pregnancy to make …

Integration Of Biomedical Imaging And Translational Approaches For Management Of Head And Neck Cancer, Abdallah Mohamed, Abdallah Mohamed

Dissertations & Theses (Open Access)

The aim of the clinical component of this work was to determine whether the currently available clinical imaging tools can be integrated with radiotherapy (RT) platforms for monitoring and adaptation of radiation dose, prediction of tumor response and disease outcomes, and characterization of patterns of failure and normal tissue toxicity in head and neck cancer (HNC) patients with potentially curable tumors. In Aim 1, we showed that the currently available clinical imaging modalities can be successfully used to adapt RT dose based-on dynamic tumor response, predict oncologic disease outcomes, characterize RT-induced toxicity, and identify the patterns of disease failure. We …

Investigation Of Genomic Instability Induced By G-Quadruplexes In The Absence Of Functional Topoisomerase 1 In Yeast, Alexandra Berroyer

Dissertations & Theses (Open Access)

Topoisomerase 1 (Top1) is an enzyme that removes transcriptionally generated negative supercoils by binding and nicking DNA. Since transcription of guanine-rich DNA leads to the formation of G-quadruplex (G4) structures, Top1’s function likely suppresses G4-formation. In support of this, Top1 significantly reduces co-transcriptional G4 DNA-associated genomic instability at a model G4-motif in Saccharomyces cerevisiae. However, whether Top1 suppresses G4-formation on a genome-wide scale in yeast remains unexplored. Therefore, I aimed to uncover if deletion of Top1 enhances genome-wide G4-formation in S. cerevisiae. As an approach to quantify global G4-formation, I expressed the G4-specific antibody BG4 from a yeast …

Tissue-Specific Matrix Control Of Cell Cohesion And Migration Signaling Complexes, Tristen Tellman

Dissertations & Theses (Open Access)

The extracellular matrix (ECM) is a complex, interconnected network of three major constituents: collagens, glycoproteins, and proteoglycans, along with their enzyme modifiers. Within this network and beyond the structural role, each ECM molecule contributes a context-specific signal that influences cellular fate and behavior. Among these behaviors, cellular migration provides an essential function in developing tissues, wound healing, and cancer cell metastasis. Using two glandular organs, the normal salivary gland and the cancerous prostate, this dissertation describes the tissue-specific composition of two ECM signaling complexes (type I hemidesmosomes and the perlecan-semaphorin 3A-plexin A1-neuropilin-1 (PSPN) complex) and translates this knowledge into viable …

The Tca Cycle As A Nexus Of Metabolic Vulnerabilities In Cancer, Sunada Khadka

Dissertations & Theses (Open Access)

Uncontrolled proliferation of cancer cells necessitates rewiring of metabolic pathways to meet biosynthetic and bioenergetic demands of proliferation and fortify redox homeostasis. An increasing body of literature suggests that mitochondrial metabolism (tricarboxylic acid cycle (TCA) and oxidative phosphorylation) is imperative for cancer cell growth and proliferation. The scope of the works presented in this dissertation is to explore the importance of mitochondrial metabolism, and primarily the TCA cycle—the anabolic factory of cancer cells and leverage it as a targetable vulnerability in cancer. Cancer cells consume anabolic nutrients that are used to generate biosynthetic precursors in the TCA cycle. Continuous efflux …

Modulation Of Kras Structure And Dynamics By Kras Ubiquitination And Membrane Depolarization, Vinay Nair

Dissertations & Theses (Open Access)

KRAS, a 21 kDa small GTPase protein, functions as a molecular switch playing a key role in regulating cell proliferation. Dysregulation of KRAS signaling by oncogenic mutations leads to uncontrolled cell proliferation, a hallmark of cancer cells. Attempts to therapeutically target oncogenic KRAS have led to limited success resulting in a need to identify new mechanisms to targeting KRAS. The interaction of KRAS with its regulators, effectors, and the membrane present one such avenue. In this study, we investigated how post-translational covalent and environmental modifications could modulate these interactions of KRAS. Using computational molecular dynamics simulations, nuclear magnetic resonance spectroscopy …

Atr-Mediated Cd47 And Pd-L1 Upregulation Restricts Radiotherapy-Induced Immune Priming And Abscopal Responses In Colorectal Cancer, Cheng-En Hsieh, Cheng-En Hsieh

Dissertations & Theses (Open Access)

Radiotherapy of colorectal cancer (CRC) can prime adaptive immunity against tumor-associated antigen (TAA)-expressing CRC cells systemically. However, incidences of abscopal tumor remission are extremely rare, and the post-irradiation immune escape mechanisms in CRC remain elusive. We report that CRC cells utilize a common DNA repair signaling pathway — ATR/Chk1/STAT3 — to upregulate both CD47 and PD-L1 in response to radiotherapy, which through engagement of SIRPα and PD-1 suppresses the capacity of antigen-presenting cells to phagocytose them thereby preventing TAA cross-presentation and innate immune activation. This post-irradiation CD47 and PD-L1 upregulation can be observed across various human solid tumor cells. Concordantly, …

Hdac6 Inhibition Reverses Long-Term Doxorubicin-Induced Cognitive Dysfunction By Restoring Microglia Homeostasis, Blake Mcalpin

Dissertations & Theses (Open Access)

One in 8 women in the US will be diagnosed with breast cancer. Currently, doxorubicin is one of the most effective chemotherapies for breast cancer. Unfortunately, up to 60% of survivors report long-term chemotherapy-induced cognitive dysfunction (CICD) characterized by deficits in working memory, processing speed, and executive functioning. Currently, no interventions for CICD have been approved by the US Food and Drug Administration. I show here that a 14-day treatment with a blood-brain barrier permeable histone deacetylase 6 (HDAC6) inhibitor successfully reverses long-term CICD following a therapeutic doxorubicin dosing schedule in female mice, as assessed by the puzzle box test …

The Effect Of Cognitive Status And Residency On Oral Health In Patients With Dementia, Nicole Stephens

Dissertations & Theses (Open Access)

Poor oral health is a predictor of cognitive decline in elderly populations and has been shown to precede dementia. As cognitive decline progresses, patients are likely to move from the community into nursing facilities. We hypothesize that severity of dementia and residency type will impact the oral health of patients with dementia. Fifty-two participants of two dementia levels were recruited from the UTHealth Neurocognitive Disorders Center and two Houston-area nursing homes. A standardized oral health assessment, plaque index, and oral bacteria analysis determined participants’ oral health status. Further, data was collected on participants’ medical history, oral hygiene habits, dietary habits, …

Computational Approaches To Understand Chemoresistance & Tumor Evolution Using Longitudinal Clinical Data And Lineage Tracing, Sahil Seth

Dissertations & Theses (Open Access)

Tumors are highly heterogeneous and dynamic, continually adapting and evolving in response to their microenvironment as well as external perturbations. Multi-region (spatial) and single cell sequencing has enabled us to anatomize the heterogeneity further and provide evidence of its association with chemo and drug resistance. To investigate this further we took two different approaches to understand the chemo-resistance, and functional heterogeneity in Triple negative breast cancer (TNBC) and Pancreatic ductal carcinoma in situ (PDAC) from an evolutionary perspective.

The first approach was to leverage tumor profiling from an ongoing randomized clinical trial in triple-negative breast cancer (ARTEMIS) to assess mechanisms …