Medicine and Health Sciences Commons^™

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

Dissertations and 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, …

Defining The Cooperation Between Mhc-I And Mhc-Ii Neoantigen-Driven T Cell Responses To Develop Effective Personalized Immunotherapies, Charmelle Williams

Dissertations and Theses (Open Access)

Immune checkpoint therapy (ICT) (e.g. anti-CTLA-4 (α-CTLA-4), anti-PD-1 (α-PD-1)) enables durable T cell-dependent anti-tumor immunity in certain cancer patients. Since a subset of patients respond to ICT, this work aims at developing a more in-depth understanding of T-cell responses to MHC class I (MHC-I) and MHC class II (MHC-II) tumor antigens that are derived from aberrant expression of non-mutant antigens or driver and passenger somatic alterations that can function as tumor neoantigens. We used a poorly immunogenic Braf^v600e Pten^-/- Cdkn2a^-/- YUMM1.7 (Y1.7) murine melanoma line with a paucity of endogenous neoantigens that is unresponsive to ICT, and …

Absolute Quantification Of Tc-99m Activity Distributions Using A Planar Molecular Breast Imaging Commercial System, Benjamin P. Lopez

Dissertations and Theses (Open Access)

Molecular breast imaging (MBI) uses two dedicated-breast semiconductor detectors to visualize the preferential uptake of technetium-99m-sestamibi (^99mTc-sestamibi) by breast cancer cells relative to surrounding benign breast tissues. Clinically, MBI is used primarily as a supplementary tool to standard-of-care mammography because of its improved detection of breast cancers, especially in women with mammographically-dense breasts. Because of a lack of image corrections, MBI applications are currently limited to qualitative evaluations of relative pixel intensities between image regions with suspected lesions and normal tissue.

The objective of this dissertation was to use Monte Carlo simulations to better characterize the MBI imaging …

Perceptions And Roles Of Genetic Counselors In Perinatal Palliative Care: Where Are We Now?, Amanda Chamberlain

Dissertations and Theses (Open Access)

After the identification of a life-limiting fetal diagnosis, a perinatal palliative care (PPC) team can provide specialized medical care and emotional support for the family throughout the pregnancy and after delivery. Although the growth of the field of PPC over the last ten years is well-documented, there is only one study to date that explores the experiences of genetic counselors with regards to PPC. This study seeks to further the understanding of genetic counselors’ current perceptions of, experiences with, and roles in the delivery of PPC.

An edited version of the Perinatal Palliative Care Perceptions and Barriers Scale was used …

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

Dissertations and 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 and 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 …

Bhlhe40: Required For Tumor Microenvironment Remodeling And Immune Checkpoint Therapy Efficacy, Avery Salmon, Avery J. Salmon

Dissertations and Theses (Open Access)

Advancements in immunotherapy treatments have become essential in the treatment of various cancers, such as those with high tumor burden like melanoma(Brahmer et al., 2012; Hodi et al., 2010). Immunotherapy, specifically immune checkpoint therapy (ICT) provides antagonist effect on specific immune checkpoints to control effector T cell functions(Pardoll, 2012). This therapy allows for the modulation of anti-tumor responses through the use of monoclonal antibodies, such as anti-CTLA-4 or anti-PD-1 that block the receptors from binding with their ligands, thus allowing for CD4⁺ and CD8⁺ T cell priming and activation(Wei et al., 2017). However, the required epigenetic and transcriptional …

Cell-Free Dna Sequencing In Multiple Myeloma, Russell Irwin

Dissertations and Theses (Open Access)

Multiple myeloma (MM) is an incurable plasma cell dyscrasia. Recent advances in MM therapy, including CAR-T therapy, have increased survival and shown the value of assessing treatment response with great sensitivity, both in acute and long-term settings. Cell-free DNA, DNA fragments which are released into circulation as a part of normal cellular turnover, is a useful and dynamic biomarker in cancer patients due to the presence of circulating tumor DNA (ctDNA), which is readily identified using next generation sequencing. Here we report the analytical sensitivity, applicability, consistency, and prognostic ability of M5Seq, a novel hybrid capture panel designed for MM …

Development Of Advanced Mr-Guided Adaptive Radiation Therapy Methods For Head & Neck Cancers On The 1.5t Mr-Linac, Brigid Mcdonald

Dissertations and Theses (Open Access)

The 1.5T hybrid MRI/linear accelerator (MR-linac) has recently been introduced into clinical practice and used for the treatment of head and neck cancers (HNC). This device enables on-line adaptive radiation therapy (ART) based on anatomical changes throughout treatment and variations in patient position. This novel technology also has the potential for advanced ART strategies such as dose-optimized ART, in which the treatment plan is optimized based on the accumulated dose over previous fractions, or biological image-guided ART, in which the plan is adapted based on individual tumor response as measured through quantitative imaging techniques such as diffusion-weighted imaging (DWI). The …

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

Dissertations and 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 and 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 and 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 …

Lipid Composition And Configuration Drive Biophysical Properties Of The Mammalian Plasma Membrane, Jessica L. Symons

Dissertations and Theses (Open Access)

In the 1970s, it was established that phospholipid (PL) classes are asymmetrically distributed across the (PM) leaflets. Recapitulating strategies coupled with newly developed, high-resolution shotgun lipidomics, our lab confirmed PL class asymmetry and surprisingly measured the endoplasmic leaflet to contain double the number of PLs vs. the exoplasmic leaflet. My re-analysis of classical studies show that PM PL abundance imbalance has been a consistent finding across decades of literature. This is surprising, because bilayers do not tolerate interleaflet area imbalances to the degree that this imbalance would suggest, which prompted us to consider the existence of an elusive membrane resident …

The Novel Role Of Dnmbp In Kidney Development, Brandy Walker

Dissertations and 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 …

Induced Cytotoxicity In Crebbp/Ep300mut Head And Neck Squamous Cell Carcinoma, Thomaia Pamplin

Dissertations and Theses (Open Access)

INDUCED CYOTOXICTY IN CREBBP/EP300mut HEAD AND NECK SQUAMOUS CELL CARCINOMA

Thomaia Pamplin

Advisor: Curtis Pickering, Ph.D.

Background: Head and neck squamous cell carcinoma HNSCC is the most common malignancy in the head and neck. Most cases are found in advanced stages and depending on the location can be treated with surgical resection and/or radiation (XRT), chemotherapy, or chemoradiation. Our lab groups have identified that HNSCC with a mutation in its CREBBP/EP300 genes can be sensitized to XRT when the histone acetyltransferase activity of CREBBP/EP300 is inhibited. This radiosensitization manifests in the form of increased cell death for …

Social Network Analysis Of Online Support Communities For Adolescent And Young Adult Cancer Survivors, Carlos Perez Aldana

Dissertations and Theses (Open Access)

There are an estimated 633,000 adolescent and young adult (AYA) cancer survivors in the U.S. and nearly 89,500 AYAs are diagnosed with cancer every year. Cancer creates developmental and life stage disruptions, which result in multiple survivorship challenges, particularly among AYAs. Despite the advances made in cancer oncology and survivorship care, AYA cancer survivors continue to face diverse and unique psychosocial needs. Research suggests that online support communities have the potential to positively impact psychosocial care by providing AYA cancer survivors with access to social support which can help them successfully transition from treatment back to normal life as well …

Leveraging Single Cell Technologies For The Characterization And Treatment Of Refractory Pancreatic Cancer, Maria Monberg

Dissertations and Theses (Open Access)

Heterogeneity is a hallmark of cancer, and the advent of multimodal single-cell technologies has helped uncover heterogeneity in a high-throughput manner in different cancers across varied contexts at an unprecedented resolution. In an effort to improve precision medicine approaches in pancreatic ductal adenocarcinoma (PDAC), a highly lethal malignancy with a mere 11% 5-year survival rate, this dissertation focuses on first questioning the assumptions of the most basic models used to study PDAC via multimodal single-cell characterization methods at multiple levels of biological organization (scCNVseq and snATACseq for DNA assays, scRNAseq for transcriptomics, and paired protein assays such as multiplexed immunofluorescence …

Perceptions Of Integrating Immersive Virtual Reality Simulation As A Teaching Methodology In A Hospital Setting, Ladonna Christy

Dissertations and Theses (Open Access)

Introduction As newly licensed nurses enter the workforce with limited experience and limited clinical reasoning skills, nursing educators must employ innovative strategies to teach graduate nurses how to identify and manage clinical deterioration – skills which are vital to saving lives and improving outcomes. Fully immersive Virtual Reality (VR), (also defined as Immersive VR) is one effective educational strategy available for hospital educators to use for preparing newly licensed nurses to recognize and manage clinical deterioration.

Objective The purpose of this study was to explore perceptions of hospital-based nurse educators, simulation specialists, and nursing leaders with respect to integrating immersive …

Postpartum Depression Screening In The Neonatal Intensive Care Unit: Maternal And Provider Perspectives, Candice Triulzi

Dissertations and Theses (Open Access)

Objective: Although mothers of preterm infants are at increased risk for postpartum depression (PPD), PPD screening conducted by neonatal providers in the Neonatal Intensive Care Unit (NICU) is currently not a standard of care. The purpose of this study was to explore maternal and provider perceptions of neonatal providers conducting PPD screening in the NICU.

Design: This study was conducted with a qualitative approach.

Setting: A 24-bed Level III NICU in Houston, TX acted as the study site.

Participants: Participants were purposively sampled (N=31) and included mothers of NICU infants (n=15) and NICU providers (n=16).

Methods: Semi-structured individual and paired …

Factors Associated With Advance Care Planning Engagement In Healthy Young Adults, Pablo J. Vasquez

Dissertations and Theses (Open Access)

Background: Advance care planning (ACP) is a process that supports individuals at any stage of health in understanding and sharing their personal values and goals pertaining current or future medical needs with their families and healthcare providers. Although ACP is applicable to adults of any age and any stage of the health continuum, it is widely associated with older or terminally ill populations, and the need for end-of-life (EOL) planning in healthy young adults is generally found unnecessary. The National Institutes of Health supports the expansion of ACP research in understudied populations. Investigating ACP in healthy young adults support such …

Identifying Risk Factors For Anchoring Bias During Emergency Department Transitions Of Care, Roni Matin

Dissertations and Theses (Open Access)

Transitions of care have been associated with breakdowns in communication and medical errors. In emergency departments (ED) these handoffs are typically known as sign outs. Sign outs provide continuity of care for ED patients whose diagnosis and care fall across shift changes. They are short interactions where pertinent information and responsibility for the patient is transferred to the physician assuming care for them. However, these exchanges may also be an opportunity for cognitive biases to be transferred or introduced, leading to erroneous decision making. Anchoring bias is known to have a significant impact on clinical decision making. Yet, little is …

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

Dissertations and 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 and 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 and 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 …

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 and 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, …

Targeting Metabolic Adaptations To Anti-Angiogenic Therapy In Ovarian Cancer, Deanna M. Glassman, Deanna Glassman

Dissertations and Theses (Open Access)

ABSTRACT

Background: Ovarian cancer is the most lethal gynecologic malignancy. Despite modest clinical improvements with anti-VEGF antibody (AVA) therapy, adaptive resistance is nearly ubiquitous and additional therapeutic options are limited. A dependence on glutamine metabolism, via the enzyme glutaminase (GLS), is a known mechanism of adaptive resistance.

Purpose: To assess the efficacy of a glutaminase inhibitor as a means of exploiting the metabolic vulnerability of glutamine dependence that develops as a result of adaptive resistance to AVA therapy.

Experimental Design: We used a glutaminase inhibitor (GLSi) synthesized at MD Anderson Cancer Center for all in vitro and in vivo experiments. …

Efficacy Of Dual Cd19-Cd79b Car In B-Cell Malignancies, Xiaoyun Cheng

Dissertations and Theses (Open Access)

Despite high clinical responses, about 30%-60% of patients with B-cell malignancies relapse following CD19-targeting chimeric antigen receptor (CAR) T cell therapy. CD19 loss is a major cause of relapse and resistance after CD19 CAR T therapy. Dual antigen targeting could overcome resistance due to antigen escape and improve outcomes after CAR T cell therapy. We hypothesized that dual CD19-CD79b CAR T cells will be effective against B cell malignancies by targeting one or both antigens. I have engineered dual CAR targeting CD19 and CD79b antigens under the control of EF1α promoter in a 3rd generation lentiviral vector. The dual CD19-CD79b …

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

Dissertations and 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 …

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

Dissertations and 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 …

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

Dissertations and 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 …