Digital Commons Network^™

Development Of Computational Tools To Target Microrna, Luo Song

Dissertations & Theses (Open Access)

MicroRNAs (a.k.a, miRNAs) play an important role in disease development. However, few of their structures have been determined and structure-based computational methods remain challenging in accurately predicting their interactions with small molecules. To address this issue, my thesis is to develop integrated approaches to screening for novel inhibitors by targeting specific structure motifs in miRNAs. The project starts with implementing a tool to find potential miRNA targets with desired motifs. I combined both sequence information of miRNAs and known RNA structure data from Protein Data Bank (PDB) to predict the miRNA structure and identify the motif to target, then I …

Genetic And Clinical Determinants Of Racial/Ethnic Differences In Multiple Myeloma Susceptibility And Outcomes Focusing On Hispanics, Alem Belachew

Dissertations & Theses (Open Access)

Multiple Myeloma (MM) constitutes 10% of diagnosed hematologic malignancies in the US, with over 12,000 deaths recorded each year. Race/ethnicity is a well-known MM risk factor, where individuals of African descent have over 2- to 3-fold increased risk of incidence compared to those of European descent. Additionally, Hispanics are diagnosed approximately three years younger than white American counterparts, for unknown reasons. Differences in clinical phenotype are also present for MM patients by ancestry, including varying rates of common initiation mutations such as IgH translocations and TP53 mutation between patients of European and African descent. Studies have begun to interrogate the …

Sine Oculis Homeobox Homolog 1 (Six1) Plays A Critical Role In The Progression Of Pulmonary Fibrosis., Cory Wilson

Dissertations & Theses (Open Access)

Idiopathic pulmonary fibrosis (IPF) is the most common idiopathic interstitial pneumonia with a median survival time of 2-4 years after diagnosis. The alarming mortality rate is due to the lack of effective treatments. IPF is a chronic disease that is characterized by alveolar destruction due to increasing extracellular matrix deposition that leads to poor lung compliance, impaired gas exchange, and ultimately respiratory failure. Repetitive alveolar epithelial injury is a central process to the underlying pathology with injury to the type II alveolar epithelial cells (AT2) specifically being a key player in the pathogenesis of IPF. Recent studies have shown that …

Subclonal Evolution Of Chronic Lymphocytic Leukemia After Allogeneic T Cell Therapies, Haven Garber

Dissertations & Theses (Open Access)

Subclonal evolution of chronic lymphocytic leukemia after allogeneic T-cell therapies

Haven Garber, MD

Advisory Professor: Jeffrey Molldrem, MD

Intratumoral genetic heterogeneity describes the molecular differences among subclones within a tumor and is a major barrier to effective therapy in many solid and liquid cancers, including chronic lymphocytic leukemia (CLL). Rare, treatment-resistant subclones can expand to compose relapsed disease during tumor evolution. Examination of malignant evolution in the context of specific treatment provides insight into the molecular lesions that mediate therapeutic response and resistance. Both chemotherapy and targeted therapy were shown to precipitate CLL subclonal evolution. We hypothesized that allogeneic T-cell …

P53 Drives A Transcriptional Program That Elicits A Non-Cell-Autonomous Response And Alters Cell State In Vivo, Sydney Moyer

Dissertations & Theses (Open Access)

Cell stress and DNA damage activate the tumor suppressor p53, triggering transcriptional activation of a myriad of target genes. The molecular, morphological, and physiological consequences of this activation remain poorly understood in vivo. We activated a p53 transcriptional program in mice by deletion of Mdm2, a gene which encodes the major p53 inhibitor. By overlaying tissue-specific RNA-sequencing data from pancreas, small intestine, ovary, kidney, and heart with existing p53 ChIP-sequencing, we identified a large repertoire of tissue-specific p53 genes and a common p53 transcriptional signature of seven genes which included Mdm2 but not p21. Global p53 activation …

Elucidating The Roles Of Il-15 In The Tumor Microenvironment, Rosa Maria Santana Carrero

Dissertations & Theses (Open Access)

ELUCIDATING THE ROLES OF IL-15 IN THE TUMOR MICROENVIRONMENT

Rosa M. Santana Carrero, B.S.

Advisory Professors: Shao-Cong Sun, Ph.D. & Kimberly S. Schluns, Ph.D.

Interleukin-15 (IL-15) is a factor that promotes activation, proliferation, cytotoxicity, and survival of CD8 T cells and NK cells, and has been shown to have anti-tumor effects. Moreover, loss of IL-15 expression in human colorectal tumors correlates with increased risk of relapse, diminished survival, decreased density and proliferation of T cells. All together these findings suggest that IL-15 expressed locally in the tumor microenvironment (TME) is an important mediator of anti-tumor responses by tumor infiltrating lymphocytes …

Inducible Epithelial Resistance Against Acute Viral Pneumonia And Chronic Asthma, Shradha Wali

Dissertations & Theses (Open Access)

Viral pneumonia remains a global health threat despite worldwide vaccination and therapeutic programs. The influenza pandemic of 1918 and SARS-CoV2 pandemic of 2019-2020 are cautionary reminders demanding the need for novel treatment strategies. Moreover, in addition to causing acute disease, respiratory virus infections are often complicated by chronic lung pathologies, such as asthma induction, progression, and exacerbation. We have reported that mice treated with a combination of inhaled Toll-like receptor (TLR) 2/6 and TLR 9 agonists (Pam2-ODN) to stimulate innate immunity are broadly protected against respiratory pathogens, but the mechanisms underlying this protection remain incompletely elucidated. Here, we show in …

Investigation Of Proliferation Suppressors In Genetic Fitness Screens, Walter Frank Lenoir Iv

Dissertations & Theses (Open Access)

Innovation of CRISPR gene-editing technology has provided scientists genome manipulation tools that allowed rapid advancement of scientific capabilities and thus improved our ability to systematically study mammalian genetic functional profiles. Genome-wide CRISPR knockout screens conducted in collections of human cell lines can knock out genes at multiple loci, and have provided new insights into functional roles for independent genes. This method has launched massive efforts in looking across genetic backgrounds for context specific genetic vulnerabilities within cancer. Much of the research effort thus far has been spent on optimizing phenotype distinctions between essential, genes required for cell fitness, and non-essential, …

Micrornas Associated With Melanoma Inflammation And Response To Pd-1 Inhibition, Robert Szczepaniak Sloane

Dissertations & Theses (Open Access)

Melanoma is an aggressive malignancy of melanocytes with historically poor outcomes. Melanoma therapy has improved markedly over the past decade with advances in molecularly targeted agents and immunotherapies. Immune checkpoint inhibitors achieve T-cell mediated anti-tumor efficacy by blocking engagement of inhibitory checkpoints on T-cells to overcome immunosuppressive signals from tumor cells and the broader microenvironment. Despite these advances, there are a significant proportion of patients who do not benefit from existing immunotherapy strategies making it a priority to identify and target the mechanisms that confer resistance to therapy. We demonstrate that microRNAs are accurate markers of microenvironment composition with prognostic …

A Pharmacological Strategy Against African Sleeping Sickness, Wahaj Zuberi

Dissertations & Theses (Open Access)

Trypanosoma brucei is a parasitic eukaryote and is the causal agent of the disease known as African sleeping sickness, transmitted via the bite of a tsetse fly. If left untreated, the parasite ultimately crosses the blood-brain eventually leading to death. Currently there are 5 approved drugs used to treat it, each with toxic side effects and effective at specific disease stages. A more effective and less toxic drug candidate is highly sought after. The essential enzyme, dUTPase, is an excellent drug target in the parasite while utilizing S. cerevisiae as a model system.

dUTPase is essential in T. brucei (tbdUTPase), …

The Genome-Wide Roles Of The Lung Lineage Transcription Factor Nkx2-1 In The Regulation Of Opposing Cell Fates In Vivo, Danielle Renae Little

Dissertations & Theses (Open Access)

Lineage transcription factors mark, promote, and maintain multiple distinct cell types originating from a common progenitor. Despite their essential role, how such factors function and bind genome wide to orchestrate the epigenetic changes necessary to form and maintain these identities in vivo is unclear. One lineage transcription factor NK Homeobox 2-1 (NKX2-1) is expressed throughout the lung epithelium during development and was thought to be lost in the extraordinarily thin cell type required for gas exchange– the alveolar type 1 (AT1) cell. Complementing precise genetic knockouts with cell type-specific ChIP-seq, ATAC-seq, and scRNA-seq, our study shows that AT1 and AT2 …

The Role Of Daam1 In Kidney Development, Vanja Krneta-Stankic

Dissertations & Theses (Open Access)

Kidneys, like most organs in our bodies, consist of a network of epithelial tubules. Kidney tubules are called nephrons, and their morphology is important for kidney function. Nephrons develop from mesodermally derived aggregates of progenitor cells. The nephric progenitors organize into nephric tubules lined with hair-like sensory projections called cilia. Many diseases of the kidney are characterized by abnormal nephron morphology with current treatment aimed at symptom control. To understand the mechanisms underlying kidney diseases and achieve the development of novel therapies, a better understanding of how nephrons develop is needed. Although the actin cytoskeleton is critical for cell behaviors …

Qki-Mediated Cholesterol Biosynthesis In Eye Lens And Myelin Of The Central Nervous System, Seula Shin, Seula Shin

Dissertations & Theses (Open Access)

Cells obtain cholesterol in two ways, de novo biosynthesis and uptake from circulation. While most tissues utilize both sources, eye lens and brain depend extensively on cholesterol biosynthesis due to the limited supply from circulation. Lens cell membrane consists of highest portion of cholesterol. Brain is the most cholesterol-rich organ, which accounts for 23% of total cholesterol. Genetic mutations of cholesterol biosynthesis enzymes in humans and animal models present cataracts and hypomyelinating disorders linked to neurological impairment. Yet, it remains unclear how gene expression of cholesterol biosynthesis is regulated in lens and brain. Therefore, studying cholesterol biosynthesis in both tissues …

A Context-Forward In Vivo Functional Genomics Platform For Target Discovery And Establishing Vulnerability Context In Pancreatic Cancer, Johnathon Rose, Johnathon Lynn Rose

Dissertations & Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a very poor patient prognosis (5-year survival of ≤ 7%). While transcriptional profiling has aided in the classification of this disease into at least two broader subtypes, this alone has so far been insufficient to inform on more nuanced patterns of oncogenic dependency. We hypothesized that a more comprehensive and granular characterization of PDAC disease diversity is required to establish relevant context for targeted therapy. To this end, we sought to establish an integrated platform to: i) more comprehensively characterize differential oncogenic signaling across our tumor models, and ii) establish …

Reversal Of Neurodegeneration By Engineered Monocytes In Alzheimer’S Disease, Chao-Hsien Chen

Dissertations & Theses (Open Access)

The health challenges posed by Alzheimer’s disease (AD) continue to grow as societies age worldwide. Accumulation of Tau-associated pathology correlates with clinical cognitive deterioration in AD. Resident myeloid cells within the central nervous system (CNS) have a limited capacity to uptake and degrade Tau; however, the resulting secretion of proinflammatory cytokines only acts to accelerate neurodegeneration. Therapeutic antibodies can reduce the neurotoxic oligomeric form of Tau (o-Tau), but in doing so they also aggravate inflammation. Attenuating mutation of the antibody Fc region can silence inflammation but also eliminates its capacity to mediate o-Tau clearance by CNS myeloid cells. Thus, there …

Packaging And Secretion Of Airway Mucins, Oanh Ngoc Hoang

Dissertations & Theses (Open Access)

In the conducting airways of the lungs, the mobile mucus gel layer sits on top of the airway epithelium, and through ciliary beating it is propelled up the trachea into the pharynx where it is swallowed and cleared. This gel layer is composed of secreted mucins that become hydrated once reaching the airway lumen. Mucins are secreted at a baseline rate and at a stimulated rate, dependent on the amount of agonist. Baseline secretion is responsible for steady clearance of inhaled particles and pathogens. Stimulated secretion is thought to play a role in trapping helminths though mucus occlusion in small …

Ionic Mechanism Of Lysosomal Function And Cell Metabolism, Jian Xiong

Dissertations & Theses (Open Access)

Two Pore Channels (TPCs) are endolysosomal ion channels that are permeable to sodium and calcium. Defects in TPCs have been implicated to impair vesicle trafficking, autophagy and cell metabolism control; however, the detailed mechanism remains largely unknown. In this study, I show that TPCs are critical for appropriate cargo delivery to the lysosomes and deletion of either TPC1 or TPC2 leads to delayed clearance of autophagosomes, resulting in enlarged lysosomes and accumulated contents inside the lysosomes. Cells with both TPC deleted also exhibit 50% reduction in lysosomal amino acids under normal culture conditions, leading to reduced homeostatic mTORC1 activation.

Glutamine …

Decoding The Evolutionary Response To Prostate Cancer Therapy Using Plasma Genome Sequencing, Naveen Ramesh

Dissertations & Theses (Open Access)

Investigating genome evolution in response to therapy is difficult in human tissue samples due to the difficulty in accessing metastatic tumor sites and logistical challenges of collecting longitudinal samples. To overcome these issues, we developed an unbiased whole-genome plasma DNA sequencing approach called PEGASUS that concurrently measures genomic copy number and exome mutations from archival cryostored plasma samples. This approach was applied to study longitudinal blood plasma samples from prostate cancer patients. A molecular characterization of archival plasma DNA from 233 patients and genomic profiling of 101 patients identified clinical correlations of aneuploid plasma DNA profiles with poor survival, increased …

Disruption Of Dna Polymerase Zeta Promotes An Innate Immune Response, Sara Martin

Dissertations & Theses (Open Access)

DNA polymerase ζ (pol ζ) is a specialized polymerase that protects cells from the consequences of DNA damage and stress. Without pol ζ function mammalian cells and yeast are exquisitely sensitive to genotoxic stresses including ultraviolet irradiation and platinum compounds such as the chemotherapeutic agent cisplatin. This elevated sensitivity arises from the central role of pol ζ in lesion bypass. Pol ζ is also required to protect cells from endogenous genomic damage or stress. In primary mammalian cells, the function of pol ζ is required for genome protection and normal proliferation. Immortalized Rev3lknockout (KO) MEFs are under considerable constitutive …

Inducible Epithelial Resistance Against Acute Viral Pneumonia And Chronic Asthma, Shradha Wali

Dissertations & Theses (Open Access)

Viral pneumonia remains a global health threat despite worldwide vaccination and therapeutic programs. The influenza pandemic of 1918 and SARS-CoV2 pandemic of 2019-2020 are cautionary reminders demanding the need for novel treatment strategies. Moreover, in addition to causing acute disease, respiratory virus infections are often complicated by chronic lung pathologies, such as asthma induction, progression, and exacerbation. We have reported that mice treated with a combination of inhaled Toll-like receptor (TLR) 2/6 and TLR 9 agonists (Pam2-ODN) to stimulate innate immunity are broadly protected against respiratory pathogens, but the mechanisms underlying this protection remain incompletely elucidated. Here, we show in …

Calcium Dyshomeostasis In Neurodegeneration, Nicholas Emanuel Karagas

Dissertations & Theses (Open Access)

Neurodegenerative diseases, despite constituting a major and growing cause of mortality globally, have few effective treatments. In order to develop novel therapeutics to combat neurodegeneration, a better understanding of the molecular mechanisms underlying these diseases is needed. Neurons rely on Ca²⁺ to mediate many of their unique functions, and aberrant Ca²⁺ signaling has been broadly implicated in neurodegeneration. The goal of this dissertation is to delineate specific examples of Ca²⁺ dyshomeostasis that I have uncovered in Drosophila models of neurodegeneration.

I first define the role a neurodegeneration-associated mutation plays in perturbing presynaptic [Ca²⁺], which is …

The Role Of Daam1 In Kidney Development, Vanja Krneta-Stankic

Dissertations & Theses (Open Access)

Kidneys, like most organs in our bodies, consist of a network of epithelial tubules. Kidney tubules are called nephrons, and their morphology is important for kidney function. Nephrons develop from mesodermally derived aggregates of progenitor cells. The nephric progenitors organize into nephric tubules lined with hair-like sensory projections called cilia. Many diseases of the kidney are characterized by abnormal nephron morphology with current treatment aimed at symptom control. To understand the mechanisms underlying kidney diseases and achieve the development of novel therapies, a better understanding of how nephrons develop is needed. Although the actin cytoskeleton is critical for cell behaviors …

Fibroblast Heterogeneity In Pancreatic Cancer Immunity, Josephine Darpolor

Dissertations & Theses (Open Access)

Fibroblasts are a unique cell type defined by their mesenchymal phenotype and exclusion from epithelial, immune, and endothelial cell subsets. Although well studied in wound healing, cancer associated fibroblasts (CAFs) are incredibly heterogeneous, leading to contradictions as to the roles CAFs play in the tumor microenvironment (TME). CAFs were thought to be a barrier to treatment of pancreatic ductal adenocarcinoma (PDAC). However, general stromal targeting strategies have largely failed in the clinic likely due to the heterogeneity of CAFs in the TME. Therefore, our groups and others have worked to unravel the heterogeneity of CAFs in PDAC. In the works …

Qki-Mediated Cholesterol Biosynthesis In Eye Lens And Myelin Of The Central Nervous System, Seula Shin, Seula Shin

Dissertations & Theses (Open Access)

Cells obtain cholesterol in two ways, de novo biosynthesis and uptake from circulation. While most tissues utilize both sources, eye lens and brain depend extensively on cholesterol biosynthesis due to the limited supply from circulation. Lens cell membrane consists of highest portion of cholesterol. Brain is the most cholesterol-rich organ, which accounts for 23% of total cholesterol. Genetic mutations of cholesterol biosynthesis enzymes in humans and animal models present cataracts and hypomyelinating disorders linked to neurological impairment. Yet, it remains unclear how gene expression of cholesterol biosynthesis is regulated in lens and brain. Therefore, studying cholesterol biosynthesis in both tissues …

Aging Lowers Pex5 Levels In Cortical Neurons In Male And Female Mouse Brains, Ndidi-Ese Uzor

Dissertations & Theses (Open Access)

Peroxisomes are small organelles with critical functions: lipid synthesis, breakdown of reactive oxygen species by antioxidant enzymes, and amino acid degradation. In the brain, peroxisomal lipids make up the myelin sheath. Brain peroxisomal dysfunction leads to lipid disruption or neurological consequences if key peroxisomal proteins are absent. Still, it is unclear how peroxisomes are affected in neurodegenerative diseases and in normal brain aging. This work examines peroxisomal markers in three settings: 1) in a neuronal and 2) animal model of Huntington disease (HD), where mutant huntingtin (mHtt), the causative protein in Huntington disease pathogenesis is expressed, and 3) in the …

Bringing Til Therapy Beyond Melanoma: Advancing The Treatment Of Advanced Pancreatic And Ovarian Cancers, Donald Sakellariou-Thompson

Dissertations & Theses (Open Access)

The success of checkpoint blockade immunotherapy (CBI) has reinvigorated the cancer therapy field, particularly for advanced melanoma which has doubled the survival rates compared to 20 years ago. However, there are many solid tumor types that are yet to receive substantial benefit from this groundbreaking therapy, two of which are pancreatic cancer (PDAC) and ovarian cancer (OvCa). As such, the 5-year survival rate for PDAC and OvCa stand at 9% and 28% respectively. Despite the lack of efficacy of CBI so far, there is still evidence for the role of immune control in these cancers as evidenced by presence of …

Mutations Within And Between Early Cell Division Proteins And Their Effects On Division Regulation In Escherichia Coli, Kara Schoenemann

Dissertations & Theses (Open Access)

Cell division is a highly regulated process that must coordinate multiple implicit activities in different locations in the cell simultaneously. E. coli utilizes a macromolecular machine known as the divisome to accomplish cytokinesis. Assembly of the divisome begins with the assembly of a simpler structure known as the proto-ring. The proto-ring consists mainly of three essential proteins: FtsZ and its membrane tethers FtsA and ZipA. In this work, I aimed to understand the early regulation of division in E. coli by investigating the structure/function relationships of the proto-ring proteins, as well as their interactions with one another and how these …

Methods To Investigate Hyperthermia Induced By Tumor Treating Fields, Ruchi Singh

Dissertations & Theses (Open Access)

Tumor Treating Fields (TTFields) are an antineoplastic treatment delivered via application of alternating electric fields using insulated transducer arrays placed directly on the skin in the region surrounding the tumor. TTF’s is a non-invasive application of low-intensity (1-3 V/cm), intermediate-frequency (100-500 kHz) alternating electric fields. The predominant mechanism by which TTFields are thought to kill tumor cells is the disruption of mitosis through the depolymerization of microtubules and interruption of the spindle structure leading to mitotic catastrophe and the formation of non-viable daughter cells. Tumor Treating fields do not stimulate nerves and muscle because of their high frequency, and do …

Identification Of Trim24 Domain Essentiality In Primary Trim24coe Carcinosarcoma Cell Lines, Cem Dede

Dissertations & Theses (Open Access)

Regulation of transcriptional control is a critical feature for organismal development and survival. Because of its effects on chromatin-controlled expression, disruptions of this delicately tuned mechanism are an important factor in development of tumorigenesis. Therefore, there is a growing interest in targeting these control mechanisms for their potential therapeutic values.

Our lab previously discovered the epigenetic regulator function of Tripartite motif protein 24 (TRIM24) through its H3K4me0 and H3K23ac dual histone signature reader function, its negative regulatory effect on the p53 tumor suppressor, in addition to its shown oncogenic driving capacity on immortalized mammary epithelial cells when overexpressed. Although TRIM24 …

Investigating The Role Of Quaking In Antigen Uptake And Cross-Presentation By Dendritic Cells, Yating Li

Dissertations & Theses (Open Access)

Dendritic cells (DCs) are considered the most potent antigen presenting cells (APC) due to their superior capability of cross-presenting exogenous antigens to CD8⁺ T cell for strong adaptive immune responses. They internalize foreign antigens by phagocytosis, endocytosis or macropinocytosis, which are then processed in endosomal compartments and loaded onto MHC Class I molecules. However, the molecular mechanisms regulating exogenous antigen uptake and cross-presentation by DCs are not fully understood.

In this study, we discovered that an RNA-binding protein, Quaking (QKI) plays a pivotal role in antigen uptake by DCs. Our previous studies in neural stem cells and microglia have …