Cell and Developmental Biology Commons^™

The Role Of Wt1 In Müllerian Duct Development, Jace Aloway

Dissertations and Theses (Open Access)

WT1 is a zinc finger transcription factor widely expressed in the urogenital system. Human mutations of WT1 lead to pediatric nephroblastoma as well as frequent differences of sex development (DSDs). Previous studies have suggested that WT1 acts as an activator for Amhr2, a necessary component of typical male differentiation. We used the mouse as a model to investigate the role of WT1 in sex development, where we deleted Wt1 in the Müllerian duct (MD) mesenchyme using a novel conditional null reporter allele, Wt1 flox-RFP. This allele utilizes the Cre-lox system to delete exons 8 and 9 of Wt1 …

Characterizing And Targeting The Genomic Consequences Of Atrx Deficiency In Glioma, Sharvari Dharmaiah

Dissertations and Theses (Open Access)

Mutational inactivation of histone chaperone ATRX (a-thalassaemia/mental retardation X-linked) represents a defining molecular feature in several cancers, including malignant glioma. As standard of care only leads to transient responses and poor outcomes, there is an unmet clinical need for developing new therapies that target ATRX-deficient glioma. Loss of ATRX gives rise to abnormal G-quadruplex DNA secondary structures at GC-rich sites of the genome, such as telomeric and pericentromeric regions, enhancing replication stress and genomic instability. These mutations are mutually exclusive with TERT promoter mutations, promoting the alternative lengthening of telomeres (ALT) pathway as a telomere maintenance mechanism in ATRX-deficient glioma. …

The Role Of Ganglioside Gd2 And Gd3 Synthase (St8sia1) In The Regulation Of Immune Suppression In Breast Cancer, Bolutyfe Oderinde

Dissertations and Theses (Open Access)

Gangliosides are acidic glycosphingolipids involved in cell adhesion, proliferation, and modulation of signal transduction pathways. It has been reported that tumor-shed gangliosides influence the activity of immune cells including macrophages, NK cells, and T cells. GD3 synthase (GD3S) is the key enzyme that regulates the biosynthesis of the b and c series gangliosides, particularly GD3 and GD2, and studies have shown that GD3S is upregulated in most tumors and plays a role in tumor progression. Similarly, we have previously found GD3S to be significantly upregulated in GD2+ breast cancer stem cells (BCSC) compared to GD2- cells, and the knockdown of …

Assessing The Temporal Role Of Mir-200 Loss In Murine Models Of Nsclc, Jared Fradette

Dissertations and Theses (Open Access)

Lung cancer is the leading cause of cancer related deaths in the United States, with non-small cell lung cancer (NSCLC) making up a majority of new diagnoses. Metastasis is the big killer in NSCLC and is driven by epithelial-mesenchymal transition (EMT) and immune evasion. The microRNA 200 family is a master regulator of EMT and is implicated in immune regulation. In this study we have developed a novel genetically engineered mouse model (GEMM) and derived primary cell lines from them to explore the role of microRNA-200 in early EMT and immune changes. Our model combines conditional activation of Kras^{G12D …}

Functional Contribution Of Epithelial To Mesenchymal Transition Program On Krasg12d Targeting Efficacy In Pancreatic Cancer, Ana S. Maldonado

Dissertations and Theses (Open Access)

Functional contribution of epithelial to mesenchymal transition program on KRAS^G12D targeting efficacy in pancreatic cancer

Ana S. Maldonado, BS

Advisory Professor: Raghu Kalluri, M.D., Ph.D.

Pancreatic Ductal Adenocarcinoma (PDAC), a highly aggressive, metastatic, and therapeutically resistant form of pancreatic cancer has been projected to become the second-leading cause of cancer related mortality in the United States. This is driven by its detection difficulty, treatment efficacy, and asymptomatic nature, among other factors. PDAC is driven predominantly by KRAS^G12D mutations, which are responsible for the initial development of pancreatic intraepithelial neoplasia (Pan-IN) lesions, that are further maintained and progressed until …

Early Onset Alzheimer’S Disease Markers In Mouse Hippocampus Unveiled By Single-Cell Transcriptomic Analysis Following Cranial Radiotherapy, Tuba Aksoy

Dissertations and Theses (Open Access)

Cranial radiation therapy plays an integral role in the treatment of brain tumors but can lead to progressive cognitive deficits in survivors by mechanisms that are poorly understood. To develop preventive or mitigative strategies, it is crucial to better understand the underlying pathogenesis of radiation-induced cognitive impairments. The study investigated single-cell transcriptomics and DNA methylation changes as potential drivers of persistent cellular dysfunction after radiation exposure, specifically concentrating on the CA1-3 regions of the hippocampus and the prefrontal cortex due to their role in cognitive functions. Thirteen-week-old mice underwent whole-brain radiation at clinically relevant doses. Following whole-brain radiation, an assessment …

Placental Co-Transcriptional Activator Vestigial-Like 1 (Vgll1) Drives Tumorigenesis Via Increasing Transcription Of Proliferation And Invasion Genes, Heather Sonnemann

Dissertations and Theses (Open Access)

Vestigial-like 1 (VGLL1) is a co-transcriptional activator that binds to TEA domain containing transcription factors (TEADs). Its expression is upregulated in a variety of aggressive cancer types, including pancreatic and basal-like breast cancer, and increased transcription of VGLL1 is strongly correlated with poor prognosis and decreased overall patient survival. In normal tissues, VGLL1 is most highly expressed within placental trophoblast cells, which share the common attributes of rapid cellular proliferation and invasion with tumor cells. The impact of VGLL1 in cancer has not been fully elucidated and no VGLL1-targeted therapy currently exists. The aim of this study was to evaluate …

Vesicle-Associated Membrane Proteins In Airway Mucin Secretion, Boxuan Yang

Dissertations and Theses (Open Access)

Mucus plays a vital role in shielding the lungs against harmful substances such as particles, pathogens, and chemicals inhaled from the environment. It captures these harmful elements, and ciliary action helps to expel them from the lungs. Paradoxically, malfunctioning of mucus induces the development of various respiratory illnesses, including asthma, cystic fibrosis, chronic obstructive pulmonary disease (COPD), and interstitial lung diseases. Despite extensive research on controlling mucin production and hydration, the process of secretion is not yet fully comprehended.

Mucin undergoes regulated secretion at two rates: a low baseline rate and a high stimulated rate. Over the past 25 years, …

The Role Of The Transcription Factor Cebpa In Regulating Lung Alveolar Type 2 Cell Fate In Vivo, Dalia Hassan

Dissertations and Theses (Open Access)

Cell plasticity can extend across all possible cell types, yet it naturally diminishes as cells progress through differentiation. This plasticity can be reactivated during injury repair, engaging developmental flexibility. Our investigations reveal the critical role of the transcription factor (TF) CEBPA, specific to lung alveolar type 2 (AT2) cells, in modulating AT2 cell plasticity within the mouse lung. We demonstrate that CEBPA constrains AT2 cell plasticity by promoting the AT2 differentiation program and recruiting the lineage-specific TF NKX2-1. Without CEBPA, AT2 cells, in both neonatal and mature, show a diminished AT2 program; however, only neonatal cells re-activate the SOX9 progenitor …

The Role Of Mettl21a In Kras-Driven Cancers, Xiaojie Yang

Dissertations and Theses (Open Access)

Abstract

More than 100 lysine methyltransferases (KMTs) were predicted to be present in the human proteome, and many were implicated in cancer etiology. However, the catalytic activity and substrate specificity for many of these enzymes remain unknown. Our work aimed to explore the role of Methyltransferase like 21A (METTL21A), amember of the little-studied seven β- strand family of candidate lysine methyltransferases (KMTs), and its role in regulating pancreatic ductal adenocarcinoma (PDAC) and lung adenocarcinoma (LUAC) tumorigenesis. Through the meta-analysis of publicly available gene expression datasets, I found that METTL21A is significantly downregulated in PDAC and LUAC versus normal tissue, and …

Oxidative Phosphorylation In Melanoma Brain Metastases: A Regulator Of The Tumor Immune Landscape, Renato A. Guerrieri

Dissertations and Theses (Open Access)

Previously, we demonstrated via RNA-sequencing analysis of murine intracranial melanoma tumors that pharmacologic inhibition of oxidative phosphorylation (OXPHOS) results in increased expression of genes consistent with activated anti-tumor immune responses. The central hypothesis of this dissertation is that OXPHOS plays a critical role in the pathogenesis and immune regulation of melanoma brain metastases (MBMs).

The functional significance of OXPHOS was assessed through genetic inhibition, involving knockout (KO) of key regulatory genes such as Ppargc1a (PGC1a) and Ndfus4 (NDUFS4), a component of mitochondrial complex I. PGC1a KO in an RCAS-TVA mouse model of autochthonous lung and brain tumors developing from primary …

Epigenetic Modification As A Therapeutic Target In Brafv600e-Mutated Metastatic Colorectal Cancer, Hey Min Lee

Dissertations and Theses (Open Access)

Patients with BRAF^V600E-mutated metastatic colorectal cancer (mCRC) experience a worse prognosis and demonstrate only a 5% response rate to BRAF inhibitor treatment. In this study, adaptive resistance, and a potential combination of standard therapies in BRAF^V600E CRC were unveiled. Intriguingly, a robust association of BRAF^V600E mutation and DNA hypermethylation suggests this is a unique subgroup harboring aberrant epigenetic phenotype. Firstly, DNA methyltransferase (DNMT) inhibitor treatment induced profound DNA hypomethylation in vivo, but minimal change in gene expression due to adaptive elevation of the repressive histone methylation, H3K27me3, leading to compensatory suppression of key tumor suppressor genes, …

Loss Of Ptdss1 In Tumor Cells Improves Anti-Pd-1 Therapy, Jielin Liu

Dissertations and Theses (Open Access)

PTDSS1 (Phosphatidylserine synthase 1) encodes an enzyme that facilitates production of phosphatidylserine (PS), which mediates a global immunosuppressive signal. Here, based on in vivo CRISPR screen, we identified PTDSS1 as a target to improve anti-PD-1 therapy. Depletion of PTDSS1 in tumor cells increased expression of IFNγ-regulated genes, including B2m, Cxcl9, Cxcl10, and Stat1. Loss of PTDSS1 in tumor cells also led to increased expression of MHC-I, which was associated with increased expression of cytolytic function related genes in CD8⁺ T cells and increased frequency of an iNOS⁺ myeloid subset. A gene signature derived from the iNOS⁺ myeloid …

The In4mer Crispr/Cas12a Multiplex Knockout Platform And Its Applications, Nazanin Esmaeili Anvar

Dissertations and Theses (Open Access)

Discovering synthetic lethal interactions between genes holds the key to uncovering cancer vulnerabilities, enabling the development of more effective drugs for patients. However, identifying these vulnerabilities in the complex genome of human, which comprises thousands of genes, poses a significant challenge. One alternative approach to investigate these interactions involves exploring enriched sources of synthetic lethal interactions, such as paralog pairs. In recent years, a couple of studies have conducted dual-gene knockout experiments on paralog pairs using different approaches to identify synthetic lethal interactions. In this study, we conducted a meta-analysis of CRISPR genetic interaction screens. We identified a candidate set …

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

Dissertations and 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 …

Histone Lysine Methyltransferase Nsd3 Governs Transcriptional Programs That Drive Pancreatic Neuroendocrine Tumors (Pannets), Mary Esmeralda Fuentes

Dissertations and Theses (Open Access)

Pancreatic Neuroendocrine Tumors (PanNETs) are the most common and lethal neuroendocrine malignancies where treatments used in advanced patients have limited efficacy, adverse side effects, and acquire resistance. Thus, there is a critical need to uncover novel precision therapeutics for PanNET patients. Additionally, pre-clinical models that more accurately represent disease are an urgent necessity for translational studies.

This dissertation directly addresses these challenges by identifying histone lysine methyltransferase (KMT) NSD3 as a critical oncogenic driver of PanNETs through di-methylation of histone H3K36 (H3K36me2).

The findings shown in this body of work indicate that H3K36 methylation by NSD3 functions as a transcriptional …

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

Dissertations and 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 and 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 and 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 and 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 …

A Signal To Divide: Apoptotic Extracellular Vesicles As Carriers Of Mitogenic And Immunogenic Signals, Safia Essien, Safia Essien

Dissertations and Theses (Open Access)

Efficient replacement of dead cells in epithelial tissue is crucial for maintaining barrier function and tissue homeostasis. Apoptotic cells can signal to neighboring cells to stimulate proliferation and compensate for cell loss and maintain overall cell numbers in normal physiology and cancer. While dying cells can transmit instructive cues to neighboring cells, the molecular mechanisms that induce cell division are not well understood. Recent evidence suggests that apoptotic bodies (ABs) or apoptotic extracellular vesicles (AEVs) mediate cell-to-cell communication and carry diverse biologically active cellular cargo which can influence cell proliferation. This dissertation visualizes and characterizes AEVs in larval zebrafish and …

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

Dissertations and 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 …

Oncogenic Kras And Telomere Biology In Crc Progression, Ronald Depinho

Dissertations and 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 …

Identifying Functional Enhancers For Fibrotic Gene Regulation In Liver Fibrosis, Parnaz Merikhian

Dissertations and Theses (Open Access)

Liver fibrosis is characterized by progressive activation of proliferating and migrating myofibroblasts that lead to accumulation of extracellular matrix (ECM). These myofibroblasts most arise from activated liver-resident hepatic stellate cells (HSCs). There is an increasing number of patients suffering from liver fibrosis in developed countries including the United States, which is anticipated to continue to grow during 2023-2033 period. TGF-β1 is a key cytokine with a significant role in regulating cell differentiation and adhesion in liver fibrosis. TGF-β signaling triggers gene expression changes in HSCs, including that of fibrotic and EMT-related genes, which then functionally promote HSCs activation and fibrogenesis. …

Acute Manipulation Of Erna Level For Dissecting Its Roles In Transcriptional Regulation, Lanxin Bei

Dissertations and Theses (Open Access)

Enhancers are the central genetic elements controlling cell-type and state specific transcription programs to dictate cell fates during development. Mechanistic understanding of enhancer action is important for both biology and disease research. In the human genome, more than 60k human enhancers were found to produce non-coding transcripts named enhancer RNAs (eRNAs). These created a new challenge to understand enhancer functions, which now are not only DNA elements that promote transcription but also RNA-producing transcription units themselves. Importantly, deregulation of eRNAs was associated with various diseases such as cancer, immune disorders, and neurodegeneration. However, the direct role of eRNAs in transcriptional …

Protein L Functionalized Microparticles For Early Detection Of Surface Markers In Heterogeneous Colorectal Lesions, Saleh Ramezani

Dissertations and Theses (Open Access)

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths among both men and women worldwide, a statistic that can be improved with early detection. Increased understanding of the tumor landscape has identified surface antigens that can be utilized to distinguish normal and cancerous tissue lining the colonic lumen. Use of antibodies conjugated to nano/micromaterials offers a means to detect these antigens, however, the heterogeneous nature of tumors makes it unlikely that antibodies against a single antigen will have sufficient sensitivity and specificity to detect all tumors. A versatile micromaterial able to be functionalized with more than one targeting …

Role Of Il-17/Il-17ra Signaling In The Pancreatic Tumor Microenvironment, Susana Castro Pando, Susana Castro Pando

Dissertations and Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is projected to become the second leading cause of cancer-related deaths. PDAC is characterized by the early establishment of a highly immunosuppressive fibro-cellular tumor microenvironment (TME). Our research has revealed the important role of IL-17 in the development and progression of pancreatic cancer, yet the specific cellular compartment responsible for IL-17-mediated tumor promotion remains unknown. We generated a transgenic mouse model with pancreatic KrasG12D activation and selective deletion of IL-17RA in the epithelial vs. immune component using either genetic manipulation or bone marrow transplantation. Deletion of IL17RA from the pancreatic epithelial compartment delayed premalignant lesion development …

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

Dissertations and 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 …

Elucidating Mechanisms Involved In Host Microbial-Tumor Interactions, Vidhi Chandra

Dissertations and Theses (Open Access)

Cancer is a rising cause of mortality worldwide. Microbiota is the collection of micro-organisms that live inside our bodies and can impact the host health and disease by interacting with the immune and metabolic systems. The relationship between the microbiota and cancer is complex. Gut and intratumoral microbiota can affect cancer development and progression by influencing patient outcomes and therapy responsiveness in several cancer types. Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer surrounded by a highly immuno-suppressive tumor microenvironment (TME) which limits efficacy of most available therapies. The tumoral niche provides a privileged microenvironment for microbial colonization that can …

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

Dissertations and 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 …