Cell and Developmental Biology Commons^™

Inosine Accelerates Cancer Cell Killing By The Experimental Antifolate Ucp1162: Implications For Novel Combination Treatments, Reshma Ramesh, Charles Giardina, Alan Kuo

Honors Scholar Theses

Antifolates disrupt one-carbon metabolism (OCM), which stops nucleotide synthesis and therefore slows down cell proliferation. Our experimental antifolate, UCP1162, stops de novo purine synthesis and thymidine synthesis by targeting the OCM pathway. We investigated whether the downstream metabolites of OCM pathway: methionine, thymidine, and inosine, affect the cell death caused by UCP1162 using MV4-11 leukemia cells. Thymidine was found to partially rescue MV4-11 cells from UCP1162, in contrast, inosine was found to accelerate the cell death caused by UCP1162. These cytotoxic effects of UCP1162 alone and in combination with inosine were irreversible, as removal of treatment did not restore cell …

The Development Of A Crispr-Based Calibrated Functional Assay For Classifying Pathogenicity Of Msh2 And Msh6 Variants In Lynch Syndrome, Olivia N. Amodeo

Honors Scholar Theses

Lynch syndrome is a hereditary disease caused by the inheritance of a mismatch repair gene variant. Individuals with this condition are predisposed to cancer development, most commonly colorectal cancer. Current guidelines for variant classification are based on numerous evidence categories, including functional evidence. However, many novel clinical variants are not well characterized, and evidence is difficult to obtain if functional assays are not calibrated.

To address this, our lab created a calibrated functional assay that calculates an odds of pathogenicity score for MSH2 and MSH6 gene variants that can be used as evidence for classifying variants of uncertain significance. This …

Reversible, Light-Controlled Inhibition Of Stim1-Mediated Calcium Signaling Using Photoswitchable Ml-9 Derivatives In Jurkat-Lucia Nfat Reporter T Cells, José L. Matute Gálvez

Honors Scholar Theses

Store-operated calcium entry (SOCE) through calcium release-activated

calcium (CRAC) channels is the dominant pathway for sustained Ca2+ influx in

non-excitable cells and is essential for T cell activation, driving downstream

signaling through the calcineurin-NFAT transcriptional axis. Dysregulation of

SOCE produces multi-systemic disease phenotypes, establishing that precise,

spatiotemporally controlled modulation of this pathway is a fundamental

therapeutic requirement. ML-9 is one of the only characterized small molecules

capable of targeting SOCE upstream at the level of STIM1 localization, but lacks

the selectivity, pharmacokinetic properties, and spatiotemporal control necessary

for therapeutic development.

This work describes the design, synthesis, and biological evaluation of …

Examining The Molecular Mechanisms Of Glucagon-Like Peptide-1 Receptor Agonists In Cancer Cell Biology, Oliver G. Sabet

Honors Scholar Theses

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are synthetic analogs of glucagon-like peptide-1 (GLP-1) used to treat obesity and diabetes by reducing blood glucose levels and appetite. While early rodent studies suggested a link between GLP-1RAs and thyroid cancer pathogenesis, evidence in humans remains inconclusive, with randomized controlled trials not supporting that link. Due to the rapid, widespread use of these drugs, concerns have expanded to other obesity-associated cancers, with conflicting findings on their role in cancer progression. With this contradictory evidence in a novel intersection of obesity medicine and oncology, this literature review aims to summarize current understandings between GLP-1-RAs and …

The Role Of Myosin L In The Survival Of Toxoplasma Gondii And The Importance Of Mlc1 For In Vitro And In Vivo Myosin F Motility, Victoria K. Yi

Honors Scholar Theses

My thesis discusses the work that I have conducted on two myosins in Toxoplasma gondii, which is an obligate intracellular parasite that has chronically infected around 10% of the American population. It causes toxoplasmosis and severe health consequences for individuals with compromised immune systems or when infections occur in utero. However, immunocompetent individuals are asymptomatic or present with subclinical symptoms. In the Heaslip lab, I investigated two myosins in the parasite: Myosin L and Myosin F. MyoL is an uncharacterized motor that localizes at the apical end of the parasite. It was shown to be important for parasite …

The Effect Of Cellular Glucose Levels On Inotersen-Mediated Target Reduction In In Vitro Cell Models, Andrea Durwin

Honors Scholar Theses

Antisense oligonucleotide (ASO) drugs are a new therapeutic modality to treat rare as well as common diseases. These drugs work to reduce disease by targeting the mRNA of the gene that causes the disease, therefore limiting the proteins that further propagate the signs and symptoms of the disorder. Many people who suffer from more severe diseases, such as Alzheimer’s, Parkinson’s, Duchenne Muscular Dystrophy (DMD), and a wide array of cancers, utilize ASO drugs for treatment, but the drug is also used with those suffering from more common diseases such as diabetes. The efficacy of ASO drugs to silence their mRNA …

Investigating Tumor Growth And Regulation In Supratentorial Ependymomas; The Impact Of Dlk1 And Egr1 Knockout, Om Sinojia

Honors Scholar Theses

Ependymomas (EPNs) are primary brain tumors that often arise from radial glial cells lining the ventricular system. Supratentorial ependymomas (ST-EPNs) are particularly aggressive, and understanding the molecular factors driving their growth is critical for developing targeted therapies. This study investigates the roles of DLK1 and EGR1, key regulators in cellular differentiation and tumorigenesis, in the development of ST-EPNs. We utilized genetically engineered mouse models to induce postnatal knockouts of DLK1 and EGR1 and evaluated tumor growth using histological and imaging techniques. Tumor area was quantified across multiple brain sections from both male and female mice. DLK1 knockout brains exhibited consistent …

Testing Vivo-Morpholino Mediated Gene Knockdown Of Stat6, Spi1b, And Hnf4Α In Adult Threespine Stickleback, Stella Dipippo

Honors Scholar Theses

The fibrotic immune response to the cestode parasite, Schistocephalus solidus, varies among threespine stickleback populations. Fibrosis suppresses parasite growth but has costly effects on the fish. Previous genomic studies in stickleback have suggested potential roles of Spi1b, STAT6, and HNF4α in modulating fibrosis severity, but there is presently no evidence for this in-vivo. We used antisense vivo-morpholino oligonucleotides (MOs) to attempt to knockdown the expression of each gene in the liver, spleen, and intestine of adult stickleback. Vivo-MOs have been proven effective in other species of teleost fish, as well as in mice and humans, but …

Identifying Novel Upstream Regulators Of The Hippo Pathway: Forward Genetic Screen In Drosophila Melanogaster, Akshara Iyer

Honors Scholar Theses

The Hippo pathway is an evolutionarily conserved developmental pathway that controls organ size and tissue homeostasis in all metazoan animals. Dysregulated Hippo pathway has been implicated in a wide range of human disorders, including cancer. The physiological function of the Hippo pathway is best understood in Drosophila, where inactivation of the Hippo pathway tumor suppressors, or overexpression of the Yorkie (Yki) oncoprotein, results in tissue overgrowth characterized by excessive cell proliferation and diminished apoptosis, and increased transcription of Hippo pathway target genes such as diap1 and expanded (ex). Despite the well-established Hippo pathway core signaling cascade, the upstream regulation of …

Immunopathogenesis Of Post-Infectious Hydrocephalus, Sascha Powers Bernier

Honors Scholar Theses

Hydrocephalus is characterized by the abnormal accumulation of cerebrospinal fluid (CSF) within the brain ventricles. In post-infectious hydrocephalus (PIH) cases, the condition presents challenges in understanding the immune response. PIH is a complex condition, often persisting after the initial infection is treated and thus requiring a deeper understanding of the immune mechanisms involved in its development. This thesis will explore the immunopathogenesis of PIH, elucidating the relationship between the immune response and neurological complications that would succeed infection. The immune response of PIH includes a series of events, beginning with the activation of immune cells and finishing with the release …

Understanding The Role Of Minor Intron Splicing In Spermatogenesis, Jade Rosado, Kazumasa Takemoto, Rahul Kanadia

Honors Scholar Theses

The minor spliceosome is composed of the unique small nuclear RNAs (snRNA), U11, U12, U4atac, and U6atac, and is necessary for the splicing of less than 0.5% of introns, termed minor introns. Minor intron containing genes (MIGs) regulate diverse processes, one of which is spermatogenesis. Specifically, 111 testis-specific MIGs have been identified, suggesting that minor splicing is necessary for spermatogenesis. To interrogate the role of minor splicing in spermatogenesis, we conditionally ablated the Rnu11 gene, which encodes for the U11 snRNA, in the developing testes via Stra8-iCre, creating a Rnu11^Flx/Flx::Stra8-Cre⁺ mutant. We found, at postnatal …

Advancements In Crispr-Cas9 Gene Editing: Applications And Future Implications For Sickle Cell Disease And Β-Thalassemia Treatment, Swetha Battini

Honors Scholar Theses

This literature review explores the utilization of CRISPR-Cas9 gene editing technology in addressing Sickle Cell Disease (SCD) and Beta-Thalassemia. CRISPR, leveraging the Cas-9 enzyme inspired by bacterial defense mechanisms, serves as a precise molecular tool for targeted genetic modifications. The process involves guide RNA directing Cas-9 to specific DNA sites, allowing for meticulous gene editing. Focusing on the specific applications of CRISPR in SCD and Beta-Thalassemia, the review critically analyzes recent methods, including CRISPR-Cas9 editing targeting the BCL11A enhancer for SCD and the HBG1/HBG2 promoters for both SCD and Beta-Thalassemia. The synthesis of findings highlights the potential and challenges of …

Development Of Vasculature Patterns In A Mouse Model Of Supratentorial Ependymoma, Jackson Ayers

Honors Scholar Theses

Supratentorial Ependymoma (ST-EPN) is a subtype of ependymoma, a primary solid tumor found throughout the nervous system. ST-EPN are most commonly caused by an oncogenic fusion between the zinc finger gene ZFTA and the RELA, and this distinct ependymoma subtype is readily modeled in mice by conditional expression of ZFTA-RELA in radial glial cells. ST-EPN are known to have a distinctive arrangement of tumor cells and vasculature forming pseudo-rosettes in which polarized tumor cells surround blood vessels within the tumors. It is not known how these pseudo-rosettes or the tumor vasculature form and develop in ST-EPN, so in this study …

A Dna-Peptide Crosslink (Dpc) Increases Mutagenicity In Sos-Induced Escherichia Coli, Alessandra Bassani

Honors Scholar Theses

Bacteria, such as Escherichia coli, have an inducible system in response to DNA damage termed the SOS response. This system is activated when the replicative DNA polymerase (Pol) III encounters a lesion, uncouples from DNA helicase, and single-stranded DNA (ssDNA) accumulates at the replication fork. In this study, we investigated DNA-peptide crosslink (DpC), a common lesion that results from cross-linking of proteins or peptides, UV irradiation, and alkylating agents. To increase survival following formation of a lesion, the SOS response can utilize homologous recombination, translesion synthesis (TLS), or excision repair. With TLS, the levels of DNA Pol II, IV, …

Oncolytic Virus Immunotherapy: Development And Potential For Cancer Treatment, Olivia Guinness

Honors Scholar Theses

The American Cancer Society estimates that in 2023, 1,958,310 new cancer cases and 609,820 cancer deaths will occur in the United States [16]. A promising therapeutic option that has been supported by recent clinical trials is the use of oncolytic viruses to treat malignant tumors. The mechanism of action of existing treatments, such as chemotherapy, radiotherapy, and surgery, differs from that of oncolytic virus therapy because oncolytic viruses are able to affect cancer cells with specificity, minimizing side effects. When infecting a normal, non-cancerous cell, oncolytic viruses do not replicate, leaving healthy cells unaffected. In tumor cells, oncolytic viruses will …

Investigating The Effects Of Cell Signaling Mutants And Inhibitors On Chemokinesis In Dictyostelium Discoideum., James Rybczyk

Honors Scholar Theses

Chemokinesis is the augmentation of cellular motility in response to chemical stimuli. While it is known that chemical factors induce changes in the behavior of a cell with regards to motility, the mechanism by which this process occurs is poorly understood. The aim of this project is to identify potential proteins within the signaling pathways that integrate the message brought on by chemical ligands and consequently lead to changes in cellular motility. In order to accomplish this goal, various gene knockout mutants of the amoeboid species Dictyostelium discoideum are compared to an axenic wild-type strain (AX2) based on their relative …

The Effect Of Fibrodysplasia Ossificans Progressiva On The Tongue, Amy Backal, Amanda Harrop, David J. Goldhamer Dr.

Honors Scholar Theses

FOP is a rare genetic disorder in which skeletal muscle and associated connective tissue progressively turn to bone through a process called heterotopic ossification (HO). The extra skeletal bone growth is cumulative, eventually trapping patients in a second skeleton that eventually leads to death by asphyxiation. The FOP mutation is autosomal dominant that can be inherited or acquired sporadically. Unfortunately, FOP is currently incurable with no therapeutic options to inhibit bone growth or reduce existing bone nodules. My project intends to further our understanding of the cellular mechanisms of the disease within the tongue muscle. A population of cells known …

Headcase Regulates Growth In Response To Nutritional Status Downstream Of Insulin Signaling, Thomas George

Honors Scholar Theses

Cancer cells are notorious for growing in an unrestricted manner without regard for environmental cues. Recently, Li et al. (2019) discovered headcase (hdc) functions by binding to the mTORC1 complex in the mTOR signaling pathway and preventing further signaling. Interestingly, under nutrient restricted (NR) conditions, cells with mutated hdc proteins proliferated more than cells with normal functioning hdc. It is well known that insulin signaling is downregulated under NR conditions, so a potential signaling pathway with insulin, PI3K, PDK1, Akt, PTEN, and hdc was created as a way to explain the link between hdc function and nutritional status. A Drosophila …

When Problems Become Solutions: Harnessing The Osteogenic Capacity Of Disease-Causing Stem Cells To Repair Bone Fractures, Mehreen Pasha

Honors Scholar Theses

While we often perceive disease as negative, there is potential to engineer seemingly negative biological phenomena into therapeutics to treat a variety of human illnesses. Fibrodysplasia ossificans progressiva (FOP) is a genetic disorder involving uncontrolled, widespread, extraskeletal bone growth, or heterotopic ossification (HO). In FOP patients, stem cells called fibro/adipogenic progenitors (FAPs) follow an abnormal, osteogenic pathway. In the present study, we investigate whether we can adapt these Acvr1 mutant FAPs, which are exceptional at producing bone, to repair bone fractures in otherwise normal patients. The primary aims of this study are (1) to devise and optimize a novel method …

The Regulation Of Chemokinesis By The Soil Amoeba, Dictyostelium Discoideum, Julia Horan

Honors Scholar Theses

Many types of cells crawl on solid surfaces by amoeboid locomotion. Membrane protrusions, such as pseudopods, are generated by outward directed forces and the cell body retracts to allow the cell to migrate on the surface. The movement can be random, or can be directional in response to diffusible (chemotaxis) or surface associated signals (haptotaxis). It has been known for some time that chemotactic signals also lead to an increase in overall cell speed (chemokinesis), however the mechanism of this speed increase is unknown. This project investigates the cellular signaling pathways involved in the regulation of cell speed by ligands …

Identifying The Cell Composition And Clonal Diversity Of Supratentorial Ependymoma Using Single Cell Rna-Sequencing, James He

Honors Scholar Theses

Ependymoma is a primary solid tumor of the central nervous system. Supratentorial ependymoma (ST-EPN), a subtype of ependymomas, is driven by an oncogenic fusion between the ZFTA and RELA genes in 70% of cases. We introduced this fusion into neural progenitor cells of mice embryos via in utero electroporation of a non-viral binary piggyBac transposon system containing ZFTA-RELA. From preliminary data in the LoTurco lab, inducing the expression of ZFTA-RELA into different neural progenitor cells produces tumors of varying lethality and cellular composition. To define the cellular composition and subclonal diversity of ST-EPN tumors, we used single cell RNA-sequencing …

The Effects Of Mapk Signaling On The Development Of Cerebellar Granule Cells, Kerry Morgan

Honors Scholar Theses

The granule cells are the most abundant neuronal type in the human brain. Rapid proliferation of granule cell progenitors results in dramatic expansion and folding of the cerebellar cortex during postnatal development. Mis-regulation of this proliferation process causes medulloblastoma, the most prevalent childhood brain tumor. In the developing cerebellum, granule cells are derived from Atoh1-expressing cells, which arise from the upper rhombic lip (the interface between the roof plate and neuroepithelium). In addition to granule cells, the Atoh1 lineage also gives rise to different types of neurons including cerebellar nuclei neurons. In the current study, I have investigated the …

Single-Fluorophore Sensors For Mechanical Force In Living Cells, Sarah Kricheff

Honors Scholar Theses

Mechanotransduction is the process by which a mechanical stimulus is converted to a cellular signal. This process is heavily influential of cell morphology, differentiation, and behavior. However, altered levels of mechanical stimuli are also found in many pathological contexts. For example, cancerous cells have stiffer surrounding tissue than healthy cells, and research suggests that this alters cell behavior and promotes metastasis. Despite these findings, the cellular processes behind these signaling alterations remain widely unknown. Understanding these cascades is critical, as involved proteins can give us a deeper understanding of the role of mechanotransduction, and certain proteins can potentially be targeted …

The Anti-Proliferative Effects Of Methotrexate And Novel Ucp1162 On Acute Myeloid Leukemia Cell Lines, Jacqueline Klepinger, Charles Giardina, Didem Ozcan

Honors Scholar Theses

Cancer cells proliferate at rapid rates due to the aberrant activity of proteins involved in regulating the cell cycle. This characteristic allows mutated cancer cells to spread and metastasize, causing lesions to form throughout the body. Two treatment conditions, one classical antifolate methotrexate (MTX) and non-classical, novel antifolate UCP1162, were tested on a panel of acute myeloid leukemia (AML) cell lines to determine if UCP1162 has higher anti-proliferative activity. High dose MTX is used as a first line chemotherapy in common childhood malignancies such as acute lymphoid leukemia (ALL). Methotrexate is excluded from acute myeloid leukemia (AML) treatments based on …

Microglia-Neuron Interactions In A Mouse Model Of Low Grade Neuroepithelial Tumors, Veolette Hanna

Honors Scholar Theses

Microglia are the macrophages of the brain and spinal cord, playing an important role in the immune response to disease states of the nervous system. This study conducts an investigation on the activity of microglia in response to low grade neuroepithelial tumors. Using mouse models and microglial markers, a qualitative and quantitative analysis of microglia activation, migration, and invasion within the brain cortex during early stages of tumor development was conducted. It was found that the presence of a low grade neuroepithelial tumor in the cortex of one hemisphere of the brain causes significant microglia activation in comparison to the …

Toxicity Analysis Of 2’-Deoxyguanosine-N2-6-Aminopyrene And 2’-Deoxyguanosine-N2-8-Aminopyrene In Escherichia Coli, Emily Janeiro

Honors Scholar Theses

Cancer is a disease that stems from genomic errors that are not corrected properly by cellular repair mechanisms. Errors are more likely to form when organisms are subjected to DNA damage by mutagenic compounds. 1-Nitropyrene, a nitrated polycyclic aromatic hydrocarbon (nitro-PAH), has been shown to be a potent mutagen that causes cancer. Nitro-PAHs can arise from diesel exhaust products in the environment. Out of all nitro-PAHs, 1-nitropyrene is found in largest quantities in the environment. This poses a great need to study its effects biochemically in order to address its toxicity in DNA. Other nitropyrene derivatives, including 1,6-dinitropyrene and 1,8-dinitropyrene, …

Characterization Of A Mycoplasma Pneumoniae Cards Toxin Mutant, Nikaash Pasnoori

Honors Scholar Theses

Mycoplasma pneumoniae is a high-burden pathogen which causes mild to significant infections of the respiratory system. According to the CDC, an estimated two million cases occur yearly in the United States alone, demonstrating the widespread effect of the pathogen. In addition to being the cause of respiratory infections, M. pneumoniae has also been implicated in exacerbating pre-existing asthma conditions. These morbidities make finding a vaccine candidate a vital part of easing the healthcare burden caused by the pathogen. The current mechanism of infection is unknown, but recent evidence points to the Community Acquired Respiratory Distress Syndrome (CARDS) toxin as being …

An Analysis Of Crispr-Cas Gene Editing In Agriculture, Ashley Laliberte

Honors Scholar Theses

The CRISPR-Cas system is a promising form of gene editing, especially for the agriculture industry. The ability to make single-nucleotide edits within a gene of interest, without the need to introduce foreign DNA, is a powerful tool for designing healthier and more efficient crops and food animals. This system provides opportunity for increased nutritional value, decreased food waste, and more economically and environmentally sustainable food production. Though this biotechnology is facing mechanistic limitations due to off-target effects and inefficient homology-directed repair, vast improvements have already been made to improve its efficacy. The CRISPR-Cas system is already the most advanced form …

Development Of A Sonically Powered Biodegradable Nanogenerator For Bone Regeneration, Avi Patel

Honors Scholar Theses

Background: Reconstruction of bone fractures and defects remains a big challenge in orthopedic surgery. While regenerative engineering has advanced the field greatly using a combination of biomaterial scaffolds and stem cells, one matter of difficulty is inducing osteogenesis in these cells. Recent works have shown electricity’s ability to promote osteogenesis in stem cell lines when seeded in bone scaffolds; however, typical electrical stimulators are either (a) externally housed and require overcomplex percutaneous wires be connected to the implanted scaffold or (b) implanted non-degradable devices which contain toxic batteries and require invasive removal surgeries.

Objective: Here, we establish a biodegradable, piezoelectric …

Embryonic Lethality Of Cranial Neural Crest Deletion Of Cdc73, Lilia Shen

Honors Scholar Theses

Hyperparathyroidism-jaw tumor (HPT-JT) syndrome is a disease characterized by parathyroid tumors, renal cysts or tumors, uterine tumors, and ossifying jaw fibromas. The cause of this syndrome is linked to a tumor suppressor gene called Cdc73, which encodes the protein product parafibromin. The loss of proper expression of Cdc73/parafibromin is implicated in the development of the tumors typical of HPT-JT, although the exact mechanisms of tumorigenesis are unclear. In particular, not much is understood about the development of ossifying fibromas (OF) of the jaw in this syndrome. OF is a benign bone neoplasm that can affect the mandible and …