Digital Commons Network^™

Exploring The Role Of Il-1Β/Il-1r In The Pathogenesis Of K-Ras Mutant Lung Cancer, Avantika Krishna

Dissertations & Theses (Open Access)

As the leading cause of cancer-related deaths worldwide, the development of targeted therapeutics to treat lung cancer remains crucial. Non-small cell lung cancer (NSCLC), the most common histological subtype predominantly comprises lung adenocarcinoma with driver mutations in the K-ras oncogene (KM-LUAD). KM-LUAD progression partly occurs through activation of the NF-κB pathway initiating an inflammatory response and creating a pro-tumor microenvironment. Notably, the pro-inflammatory cytokine IL-1β a potent activator and product of the NF-κB pathway is elevated in the lungs and sera of KM-LUAD patients. We have shown that IL-1β blockade promotes an anti-tumor immune phenotype in a mouse model of …

Importance Of Specific Nk Cell Subsets For Antitumor Immunity In Hpv+ Cancers, Madison O'Hara

Dissertations & Theses (Open Access)

High-risk type human papillomaviruses (HPV) are associated with genital and oral cancers, and the incidence of HPV+ head and neck squamous cell cancers is fast increasing worldwide. Survival rates for patients with locally advanced disease are poor and variable after standard of care (SOC) treatment. Identifying the antitumor host immune mediators important for treatment response and designing strategies to promote them are essential for improving clinical outcome. The natural killer (NK) cells are a critical component for antitumor innate effector immunity. Among the multitude of activation and inhibitory receptors on immune cells, HLA-DR is recognized as an important activation marker …

Biophysical Model Of Retraction Motor Neurons And Their Modification By Operant Conditioning, Maria Rasheed

Dissertations & Theses (Open Access)

Operant conditioning (OC) is a form of associative learning in which an animal modifies its behavior based on the consequences that follow that behavior. Despite its ubiquity, the underlying mechanisms of OC are poorly understood. Insights into the mechanisms of OC can be obtained by studying Aplysia feeding behavior as it can be modified by OC. This behavior is mediated by a central pattern generator (CPG) network in the buccal ganglia that contains a relatively small number of neurons. This CPG generates rhythmic motor patterns (BMPs) that move food into the gut by closing a tongue-like structure (i.e., radula) during …

Syntaxin-3 Mediates Baseline And Stimulated Mucin Secretion, Brianne Wharton

Dissertations & Theses (Open Access)

There are two rates at which airway epithelial cells secrete mucin. The low baseline rate accounts for ciliary clearance, and the high stimulated rate obstructs airways in protection from helminths or in obstructive pulmonary diseases. The exocytosis of mucins occurs via the four-helix SNARE complex. The SNARE proteins contributing helices are the vesicle-SNARE VAMP, and the target-SNAREs SNAP and Syntaxin. Coiling of the complex fuses the granule and plasma membranes to release mucins into the extracellular space. The VAMP and SNAP isoforms mediating baseline and stimulated secretion are known, but the Syntaxin (Stx) isoform remains unknown.

Three candidate exocytic Stx, …

Role Of The Immune System In The Modulation Of The Mmr-Deficient Intestinal Stem Cell Niche, Shepard Conner

Dissertations & Theses (Open Access)

Mismatch Repair (MMR) is a crucial DNA repair system to maintain genomic integrity in cells that is integrated by specific genes including MLH1, MSH2, MSH6, and PMS2. These genes play a critical role in repairing errors that occur in base pairing by stabilizing the genetic material. When the MMR system fails to correct those errors, MMR deficiency occurs where monoallelic mutations in the MMR genes result in a condition known as Lynch Syndrome (LS). LS makes up approximately 3% of all colorectal cancer (CRC) and is regarded as a hereditary form of CRC, which progresses from MMR-deficient …

Oncogenic Kras And Telomere Biology In Crc Progression, Ronald Depinho

Dissertations & Theses (Open Access)

While colorectal cancer (CRC) patients diagnosed with localized stage disease (as defined by SEER) have a 5-year survival rate of 90%, this rate plunges to 14% for patients diagnosed with metastatic CRC. Consequently, there is an immediate imperative to elucidate the mechanisms that drive the transition to advanced CRC.

Human CRCs carrying oncogenic mutations in the KRAS oncogene, henceforth referred to as KRAS*, exhibit a 25% higher propensity for developing liver metastases. Similarly, in our CRC mouse model, engineered with an inducible Kras* transgene and conditional null alleles of Apc and Tp53 (referred to as iKAP), KRAS* has been …

Genomic Characterization Of Adolescent And Young Adult Cancers: Investigation Of Ewing Sarcoma Susceptibility And Chornobyl Thyroid Tumors, Olivia Lee

Dissertations & Theses (Open Access)

Adolescent and young adult (AYA) cancers, diagnosed between the ages of 15 and 39, can exhibit distinctive genetic and molecular characteristics. Reported epidemiologic findings and treatment outcomes based on pediatric and adult cancer studies are often not suitable for application to the AYA population, underscoring the need for more thorough genomic research. Advances in sequencing technologies have enabled comprehensive analyses of complex genomic characteristics of AYA cancers, crucial for understanding the underlying biology of these malignancies. Here, I have utilized advanced sequencing techniques and integrated analytic approaches to describe important genomic features in two different AYA cancer types: Ewing Sarcoma …

Investigating The Role Of Il-10 Producing Nkt Cells In Prevention Of Graft Versus Host Disease, Drew Boagni

Dissertations & Theses (Open Access)

The standard curative treatment for hematologic malignancies is allogeneic stem cell transplantation (ASCT), in which the patient’s immune system is replaced with that of a healthy donor. This can lead to cure through the graft versus leukemia (GVL) effect but can also cause graft versus host disease (GVHD), which is characterized by systemic inflammation and organ damage mediated by dysregulated donor T cells. Preclinical studies have shown invariant natural killer T cells (iNKT) cells can prevent GVHD while preserving GVL. iNKT cells are unconventional T cells which recognize glycolipid antigens presented in the context of CD1d. Upon activation, they secrete …

Regulation Of De Novo And Maintenance Dna Methylation By Dnmt3a And Dnmt3b, Yang Zeng

Dissertations & Theses (Open Access)

DNA methylation (5-methylcytosine, 5mC) is essential for the regulation of gene expression and integrity of the mammalian genome. It occurs predominantly in the context of CpG dinucleotides to form a symmetrical pattern on both DNA strands, which allows DNA methylation patterns to be semi-conservatively maintained during DNA replication. There are two classes of DNA methyltransferases (DNMTs): DNMT3A and DNMT3B function primarily as de novo methyltransferases that establish DNA methylation patterns, whereas DNMT1 is the major enzyme responsible for maintaining DNA methylation patterns by converting hemi-methylated CpGs to fully methylated CpGs during DNA replication. Two accessory factors also play critical regulatory …

Uncovering Molecular Targets To Overcome Immunosuppression In Non-Small Cell Lung Cancer With Acquired Tki Resistance, Sonia A. Patel

Dissertations & Theses (Open Access)

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related deaths worldwide. Targeted therapeutic agents, such as epidermal-like growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) or monoclonal antibodies targeting vascular endothelial growth factor (VEGF/R), can effectively inhibit upregulated signaling pathways driving tumorigenesis in NSCLC and many other cancers. Unfortunately, however, resistance to such targeted therapies inevitably arise in most patients and can occur through a variety of resistance mechanisms including genomic alterations and upregulation of bypass pathways. Additionally, patients who have acquired resistance to these targeted agents typically have tumors characterized by an immunosuppressive tumor microenvironment and thus …

Kir-Based Inhibitory Cars Overcome Car-Nk Cell Trogocytosis-Mediated Fratricide And Tumor Escape, Ye Nmn Li

Dissertations & Theses (Open Access)

Trogocytosis is an active process that transfers surface material from targeted to effector cells. Using multiple in vivo tumor models and clinical data, we report that chimeric antigen receptor (CAR) activation in natural killer (NK) cells promoted the transfer of the CAR-cognate-antigen from tumor to NK cells, resulting in (1) lower tumor antigen density, thus impairing the ability of CAR-NK cells to engage with their targets, (2) induced self-recognition and continuous CAR-mediated engagement, resulting in fratricide of trogocytic antigen expressing NK cells (NK^TROG+) and NK cell hyporesponsiveness. This phenomenon could be offset by a dual-CAR system incorporating both …

Y Chromosome Gene Kdm5d Epigenetically Drives Sex Differences In Colorectal Cancer, Jiexi Li

Dissertations & Theses (Open Access)

Sex exerts a profound impact on cancer incidence, spectrum and outcomes, yet the molecular genetic bases of such sex differences are ill-defined and presumptively ascribed to X-chromosome genes and sex hormones. Such sex differences are particularly prominent in colorectal cancer (CRC) where men experience higher metastases and mortality. A murine CRC model, engineered with an inducible transgene encoding oncogenic mutant KRAS^G12D and conditional null alleles of Apc and Trp53 tumor suppressors (designated iKAP), revealed higher metastases and worse outcomes specifically in males with oncogenic mutant KRAS (KRAS*) CRC. Integrated cross-species molecular and transcriptomic analyses identified Y-chromosome gene histone demethylase …

Genetic Regulation Of Müllerian Duct Regression, Malcolm Moses

Dissertations & Theses (Open Access)

Mammals, including humans, develop progenitor tissues for both male and female reproductive tract organs before they fully differentiate into a male or female tract. The progenitor tissue for the male reproductive tract is known as the Wolffian duct (WD), and the progenitor tissue for the female reproductive tract is the Müllerian duct (MD). The WD further differentiates into the vas deferens, epididymis, and seminal vesicle, while the MD differentiates into the oviduct, uterus and upper vagina. An essential step in sex differentiation for males is the regression of the MD. This regression initiates with anti-Müllerian hormone (Amh) transcription …

Preclinical Evaluation Of Immunomodulatory Effects Of Aurora Kinase Inhibition In Human Papillomavirus Positive Cancers, Pragya Sinha

Dissertations & Theses (Open Access)

Human papillomavirus (HPV) is the causative agent of cervical cancer and some cancers of the penis, vulva, vagina, anus, and oropharynx. Current therapies for these cancers include a combination of surgery, radiotherapy, and chemotherapy that often results in permanent, life altering adverse effects. Immunotherapy is partially effective, but with significant recurrence and lower long-term survival. Importantly, there are no few biomarker-selective targeted therapies for these cancers. To address this unmet need, our collaborators conducted a large-scale drug screen and identified Aurora Kinase (AK) inhibitors as a unique class of reagents to induce selective apoptosis in HPV+, but not HPV- human …

P53 Dimers Elicit Unique Tumor Suppressive Activities Through An Altered Metabolic Program, Jovanka Gencel-Augusto

Dissertations & Theses (Open Access)

p53 is the most frequently mutated tumor suppressor in human cancer. As a tetrameric transcription factor, mutation of the p53 Tetramerization Domain (TD) is a mechanism by which cancers abrogate wild-type (WT) p53 function. p53 TD mutations result in a protein that preferentially forms monomers or dimers. These are also normal p53 states under basal cellular conditions. Although it is accepted that tetrameric p53 is required for full tumor suppressive activities, the physiological relevance of monomeric and dimeric states of p53 is not well understood. We have established in vivo models for monomeric and dimeric p53 which model Li-Fraumeni Syndrome …

Functional Analysis Of Daxx In Tumorigenesis Of Pancreatic Neuroendocrine Tumors And Embryonic Development, Chang Sun

Dissertations & Theses (Open Access)

Death domain-associated protein 6 (Daxx) is a histone chaperone specific to Histone 3.3 (H3.3). DAXX interacts with ATRX forming a chromatin remodeling complex, which deposits H3.3 into telomeric and pericentric region of the genome. The importance of Daxx was manifested in embryonic development. The loss of Daxx leads to early lethality in mouse embryos around E6.5. Moreover, sequencing studies have revealed the importance of DAXX in human tumors. Mutually exclusive mutations in DAXX and ATRX occur in about 30% of pancreatic neuroendocrine tumors (PanNETs). Although lots of progress has been made in studying functions of DAXX, we still do not …

Targeting Metabolic Alterations Associated With Smooth Muscle Α-Actin Pathogenic Variant Attenuates Moyamoya-Like Cerebrovascular Disease, Anita Kaw

Dissertations & Theses (Open Access)

Heterozygous pathogenic variants in ACTA2, encoding smooth muscle α-actin (α-SMA), predispose to thoracic aortic aneurysms and dissections. De novo missense variants disrupting ACTA2 arginine 179 (p.Arg179) cause a multisystemic disease termed smooth muscle dysfunction syndrome (SMDS), which is characterized by early onset thoracic aortic disease and moyamoya disease-like (MMD) cerebrovascular disease. The MMD-like cerebrovascular disease in SMDS patients is marked by bilateral steno-occlusive lesions in the distal internal carotid arteries (ICAs) and their branches. To study the molecular mechanisms that underlie the ACTA2 p.Arg179 variants, a smooth muscle-specific Cre-lox knock-in mouse model of the heterozygous Acta2 R179C variant, termed …

Hypoxia Activated Prodrug And Anti-Angiogenic Therapy Cooperate To Treat Pancreatic Cancer But Elicit Immune Suppressive G-Mdsc Infiltration, Arthur Liu

Dissertations & Theses (Open Access)

We previously showed that the hypoxia-activated prodrug TH-302 (Evofosfamide) reduces intratumoral hypoxia through a tissue remodeling process, initiates tumor vasculature reorganization, and sensitizes aggressive, spontaneous murine models of prostate cancer to immune checkpoint blockade (ICB). In a clinical trial testing the combination of TH-302 with cytotoxic T-lymphocyte-associated protein (CTLA-4) blockade (NCT03098160) a subset of metastatic, ICB refractory patients showed prolonged progression free survival. While these studies highlight hypoxia as therapeutically tractable, we lack a complete understanding of the contribution of the tumor vasculature to hypoxia reduction therapy, as well as the downstream consequences of hypoxia reduction on the cellular composition …

Regulation And Function Of Zeb1 Acetylation In Lung Adenocarcinoma Progression And Metastasis, Mabel Perez-Oquendo

Dissertations & Theses (Open Access)

Lung cancer metastasis is leading the causes of cancer-related mortality in the United States and worldwide. Epithelial-to-mesenchymal transition (EMT) is a model for metastasis that results in loss of specialized epithelial cell contacts and acquisition of mesenchymal invasive capacity. Zinc finger E-box-binding homeobox 1 (ZEB1) recognizes and binds to E-boxes of epithelial gene promoters to repress its transcription. ZEB1 has inconsistent molecular weights, which have been attributed to post-translational modifications (PTMs). In the presented dissertation, I specifically addressed the gap in the molecular mechanisms by which PTMs of ZEB1 regulate its ability to induce EMT and how its activity might …

Adipocytes And Innate Immunity In Systemic Sclerosis, Nancy Wareing

Dissertations & Theses (Open Access)

Systemic sclerosis (SSc; scleroderma) is a chronic systemic autoimmune and connective tissue disorder characterized by vasculopathy, autoimmune phenomena, and widespread fibrosis. Skin thickening and tightening is the cardinal feature of SSc and is responsible, in part, for the considerable morbidity of this disease. There are currently no targeted treatments for skin manifestations in SSc, primarily due to our fragmented understanding of its pathophysiologic mechanisms. In PART I, we report a previously unappreciated link between aberrant expression of the developmental gene sine oculis homeobox homolog 1 (SIX1) in skin-associated adipocytes in SSc skin and the early loss of dermal white adipose …

Unique Transcriptional Profiles Underlie Osteosarcomagenesis Driven By Different P53 Mutants, Dhruv Chachad

Dissertations & Theses (Open Access)

Missense mutations in the DNA binding domain of the Trp53 gene are characterized as structural (p53R172H) or contact (p53R245W) mutations based on their effect on the conformation of the protein. These mutations show gain-of-function activities such as increased metastatic incidence as compared to p53 loss, often mediated by their interaction with a repertoire of transcription factors. These interactions are largely context specific. In order to understand the mechanisms by which these mutations drive osteosarcoma progression, we created a mouse model, wherein either the p53 structural mutant p53R172H, or the contact mutant, p53R245W, are expressed specifically in …

Potentiation Of The Immune Checkpoint Blockade Response By Metabolic Modulation Is Predictable Using Molecular Imaging, Renee L. Chin

Dissertations & Theses (Open Access)

Unregulated cell division is a hallmark of cancer. The high metabolic needs of the tumor cells result in nutrient depletion and produce a hostile tumor microenvironment (TME) for antitumor immune cells, protecting the tumor from immune cell-mediated control and immunotherapy. Two of these environmental factors, acidosis and hypoxia, are commonly found in solid cancers. In my thesis, I posited that modulation of tumor acidosis and hypoxia can serve as biomarkers by indicating immunogenicity and tumor sensitivity to immune checkpoint blockade (ICB) as monitored using molecular imaging. Esomeprazole was found to promote tumor immunogenicity and induce tumor control when used to …

Low Molecular Weight Cyclin E Deregulates Dna Replication And Damage Repair To Promote Genomic Instability In Breast Cancer, Mi Li

Dissertations & Theses (Open Access)

Low molecular weight cyclin E (LMW-E) are oncogenic forms of cyclin E that are post translationally generated by neutrophil elastase (NE) mediated cleavage of the 50 KDa full-length cyclin E1 (FL-cycE, encoded by CCNE1gene). The resultant N-terminus deleted (40 amino acids) form of LMW-E is detected in breast cancer cells and tumor tissues, but not in normal mammary epithelial cells or adjacent normal tissues. Unlike FL-cycE, LMW-E drives mammary epithelial cell transformation in human cells and spontaneous mammary tumor formation in transgenic mouse models, but the oncogenic mechanisms of LMW-E and its unique function(s) independent of FL-cycE are not …

S-Acylation Is A Key Regulator Of Orai1/Stim1-Mediated Store-Operated Calcium Entry In T Cells, Savannah J. West Diaz

Dissertations & Theses (Open Access)

Orai1 and STIM1 proteins are the essential components of the Ca²⁺ release activated Ca²⁺ (CRAC) channel which is required for store-operated Ca²⁺ entry (SOCE) in T cells and subsequent signaling events leading to T cell activation, proliferation, and differentiation. Plasma membrane (PM)-localized Orai1 is the pore-forming subunit of the CRAC channel, and STIM1 is the Ca²⁺ sensor localized to the endoplasmic reticulum (ER) membrane in quiescent T cells. T cell receptor (TCR) stimulation leads to depletion of ER Ca²⁺ stores resulting in Ca²⁺ no longer being bound to STIM1. This activates STIM1 by triggering …

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 …

The Adar-Mavs Pathway Is A Critical Mediator Of The Innate Immune System In Pancreatic Development And Cancer, Dhwani Rupani

Dissertations & Theses (Open Access)

Adenosine deaminase acting on RNA (ADAR) is an RNA-binding protein that deaminates adenosine (A) to inosine (I). A-to-I editing is an important post-transcriptional mechanism to prevent recognition of endogenous RNA by MDA5, a cytosolic RNA sensor. Activation of MDA5 by viral RNA can stimulate the innate immune system. Thus, ADAR-mediated RNA editing is crucial to distinguish “self” from “non-self”. ADAR has an important role in gene regulation as A-to-I editing alters RNA processing affecting both RNA and protein abundance. Given its importance in regulating innate immunity and transcript abundance, aberrations in Adar expression are implicated in developmental deformities and carcinogenesis. …

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 …