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Understanding And Targeting The Immunosuppressive Tumor Microenvironment, Li Cai, Li Cai

Dissertations & Theses (Open Access)

Immune checkpoint inhibitors (ICIs), such as anti-PD1/PD-L1 and anti-CTLA-4, have shown impressive antitumor efficacy by improving the activity of T cells. While these inhibitors work in many patients with various cancer types, they have minimal or no effect in many more patients. Mounting evidence indicates that, besides current known immune checkpoints, other immunosuppressive components in the tumor microenvironment (TME) need to be targeted to elicit the full immune responses.

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of immunosuppressive myeloid cells that are involved in cancer progression and therapeutic resistance. In this work, we demonstrated the essential role of MDSCs …

Doxorubicin-Induced Cardiotoxicity Is Mediated By Neutrophils Through Release Of Neutrophil Elastase, Anchit Bhagat

Dissertations & Theses (Open Access)

Doxorubicin (Dox) is one of the most effective chemotherapy agents that is used for the treatment of childhood cancer. Unfortunately Dox treatment can cause damage to the heart. Indeed, childhood cancer survivors are at a higher risk of developing a cardiovascular disease at an earlier age. The mechanisms by which Dox causes acute and late cardiotoxicity are not completely understood. One understudied area in Dox-induced cardiotoxicity is the contribution of inflammation and innate immune cells, in particular neutrophils. Recognizing that neutrophils have been implicated in a number of heart diseases, we evaluated the role of neutrophils in Dox-induced cardiotoxicity. Here, …

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

Dissertations & Theses (Open Access)

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

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

Dissertations & Theses (Open Access)

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

Genetic Analysis Of Rna Exosome Complex Cofactors, Luisa Orlando

Dissertations & Theses (Open Access)

The RNA exosome complex is known to process and/or degrade many classes of RNA, including mRNA, rRNA, tRNA and snRNA, through its 3’-to-5’ exoribonuclease catalytic activity. The RNA exosome complex comprises a 9-unit core (exo-9), with six proteins making up a PH-Ring barrel and three proteins making up a S1-KH cap. The RNA exosome complex exo-9 core is inactive by itself and requires different cofactors in the nucleus and cytoplasm to perform different localized functions. This exo-9 core can associate with one or two catalytic subunits, including Rrp44/Dis3 and Rrp6 in yeast and DIS3 or DIS3L and RRP6/EXOSC10 in humans. …

Redox Sensing By Yeast Hsp70 Facilitates Modulation Of Protein Quality Control And The Cytoprotective Response, Alec Santiago

Dissertations & Theses (Open Access)

Neurodegenerative disease affects millions of Americans every year, through diagnoses such as Alzheimer’s, Parkinson’s, and Huntington’s diseases. One factor linked to formation of these aggregates is damage sustained to proteins by oxidative stress. Cellular protein homeostasis (proteostasis) relies on the ubiquitous Hsp70 chaperone family. Hsp70 activity has been previously shown to be modulated by modification of two key cysteines in the ATPase domain by oxidizing or thiol-modifying compounds. To investigate the biological consequences of cysteine modification on the Hsp70 Ssa1 in budding yeast, I generated cysteine null (cysteine to serine) and oxidomimetic (cysteine to aspartic acid) mutant variants of both …

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. …

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

Dissertations & Theses (Open Access)

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

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

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, …

The Functional Role Of Anatomical Feedback Connections In Visual Attention, Samantha Debes

Dissertations & Theses (Open Access)

Entrenched in a dense, highly connected network, cortical neurons receive heterogeneous inputs from diverse connections, including local feedforward and feedback signals. Over the years, neuroscientists have focused on feedforward and local connections, amassing a wealth of information on the purpose of these signals. However, the functional role of feedback connections remains a mystery, despite their sheer abundance and prevalence when compared to feedforward connections. The field has long hypothesized that feedback acts as a conduit for attentional signals, carrying them throughout the brain. Previous work on this topic has been variable. Though cognitively demanding neural processes, like attention, have traditionally …

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) …

Non-Photic Mechanisms Of Entrainment In Bmal1 Deficient Conditions, Jamie Tran

Dissertations & Theses (Open Access)

Maintaining our internal circadian (i.e. 24 -hour) clock is imperative to our daily biological and mental well-being. Large epidemiological studies have shown that disruptions of our circadian rhythms can lead to poor mental health, metabolic diseases, and various types of cancer. Various external cues that have become a part of the modern times such as electricity, shift -work, rapid travel across various time zones, easier access to nutritionally unbalanced food items, and various rigid social demands have deleterious effects on our internal clock, and generally reduce robustness of the circadian clock. The two following projects aim to examine two fundamental …

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 …

Analysis Of The Distributed Representation Of Operant Memory In Aplysia, Renan Murillo Costa

Dissertations & Theses (Open Access)

Operant conditioning, a ubiquitous form of learning in which animals learn from the consequences of behavior, engages a high-dimensional neuronal population space spanning multiple brain regions. A complete characterization of an operant memory remains elusive. Some sites of plasticity participating in the engram underlying an example of operant memory in Aplysia have been previously uncovered. Three studies are described here that sought to draw closer to a thorough characterization of this memory. The first study used a computational model to examine the ways in which sites of plasticity (individually and in combination) contribute to memory expression. Each site of plasticity …

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

Dissertations & Theses (Open Access)

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

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

The Novel Role Of Dnmbp In Kidney Development, Brandy Walker

Dissertations & Theses (Open Access)

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

Genomewide Crispr/Cas9 Screen Identifies Network Of Protein Complexes That Regulate Trim24, Lalit Patel

Dissertations & Theses (Open Access)

TRIM24 is an oncogenic chromatin reader that is frequently overexpressed in human tumors and associated with poor prognosis. However, TRIM24 is rarely mutated, duplicated, or rearranged in cancer. This raises questions about how TRIM24 is regulated and whether changes in its regulation are responsible for its activity in cancer.

To investigate this possibility, I performed a genomewide CRISPR/Cas9 screen library using fluorescence activated cell sorting (FACS) to identify regulators of TRIM24. The screen was enabled by two innovations. I engineered cells with an in-frame knock-in of mClover3 to the endogenous copy of TRIM24 to allow fluorescent monitoring of TRIM24 expression …

Decoding Copy Number Substructure And Evolution From Single Cell Genomics, Darlan Conterno Minussi

Dissertations & Theses (Open Access)

Aneuploidy is a prominent feature in Triple-Negative Breast Cancers (TNBC), however, the evolution of genotypes during tumor expansion remains poorly understood. The prevalent model of TNBC evolution is the Punctuated Copy Number Evolution (PCNE), in which tumors undergo a period of elevated genomic instability, acquiring complex genomic rearrangements within a short timeframe followed by clonal stasis. However, these observations rely on limited cell numbers and inherent experimental bias from first-generation single cell technologies. Therefore, the evolutionary trajectory after the punctuated burst remains unknown. To address this question, we sequenced 9,765 cells from 8 primary TNBCs and 6,413 cells from 4 …

Haplotype-Informed Allelic Imbalance Detection From Rna In Cancer, Zuhal Ozcan

Dissertations & Theses (Open Access)

Comprehensive genomic and transcriptomic characterization of tumors has uncovered enrichment for distinct aneuploidy and expression patterns, demonstrating the utility of molecular based classification of cancers and their subtypes. Existing cohorts with transcriptomic profiling from next-generation sequencing contain an untapped potential to also relate genomics with rich clinical phenotypes. Yet, derivation of somatic copy number and expression profiles from analyses of RNA has remained elusive. Further, DNA analysis in these cohorts is not always feasible due to limited tissue availability or financial constraints. Here, we present a statistical approach that overcomes these challenges using haplotype information to aid detection of somatic …

Integrin-Mediated Mechanotransduction Controls Activation Of Yap And Invasive Growth Of Breast Cancer, Xiaobo Wang

Dissertations & Theses (Open Access)

Tumor extracellular matrix (ECM) stiffness is correlated with the aggressiveness of breast cancer. Integrin-mediated adhesion and signaling are crucial for mammary tumorigenesis and tumor progression, in which focal adhesion kinase (FAK) - Src family kinases (SFKs) serves as a hub to relay the mechanical cues from the ECM. We have investigated the mechanisms through which integrin signaling controls mammary tumorigenesis and found that integrin-mediated mechanotransduction controls invasive growth of breast cancer cells in stiff matrices through activation of FAK and YAP. Mechanistic studies revealed that integrin signaling induces - via activation SFKs - tyrosine phosphorylation and inactivation of LATS1 and …

Decoding The Tumor And Immune Microenvironment In Pdac And Breast Cancer By Single Cell Sequencing., Aislyn Schalck

Dissertations & Theses (Open Access)

This work utilizes single cell RNA sequencing to identify transcriptional populations and gene changes for the purpose of immune-related cancer therapies. First we have characterized the T cell populations of the normal and malignant human pancreas. Furthermore, we utilized single cell TCR sequencing to track transcriptional states of T cell clones from human PDACs into a T cell culture product for adoptive cell therapy. Second, we examined the potential role of radiotherapy in inducing an immune response in hormone receptor positive breast tumors.

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

Dissertations & Theses (Open Access)

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

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

Dissertations & Theses (Open Access)

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

A Molecular And In Vivo Investigation Of Advanced Prostate Cancer: Deconstructing Ampk Activity And Developing An Improved Mouse Model, Sandi Wilkenfeld

Dissertations & Theses (Open Access)

Prostate cancer is one of the leading causes of cancer-related death in men. Prostate cancer is dependent on androgen receptor (AR)-mediated pathways, and AR is therefore targeted to treat advanced prostate cancer. Despite an initial response to current AR-targeted therapies, patients invariably relapse, due in large part to the reactivation of AR through a variety of mechanisms. My goal is to identify pathways downstream of AR that can be therapeutically targeted. We and others previously demonstrated that in prostate cancer, calcium/calmodulin-dependent kinase kinase 2 (CaMKK2) is a direct downstream target of AR, and can promote disease progression through the phosphorylation …

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

Dissertations & Theses (Open Access)

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

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

Dissertations & Theses (Open Access)

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

Parental Stress In Tuberous Sclerosis Complex, Jenny Do

Dissertations & Theses (Open Access)

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

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

Dissertations & Theses (Open Access)

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

Exploiting Chemogenetic And Genetic Interactions In Human Cells As An Avenue For New Therapeutic Opportunities, Medina Colic

Dissertations & Theses (Open Access)

The advent of CRISPR technology and its adaptation to the mammalian genome made whole-genome knockout screens possible directly in human cells. Gene knockout answers how essential that gene is for cell fitness and proliferation. Genes showing moderate to severe fitness defects are called essential genes and provide insights into disease-specific candidate therapeutic targets. Additionally, CRISPR offers other applications for genome editing. Two applications this dissertation is based on are 1) combination of gene knockout and drug treatment, which enables the identification of chemogenetic interactions, or gene mutations that enhance or suppress the activity of a drug, and 2) combinatorial editing, …