Medical Molecular Biology Commons^™

Kras-Independent Factors Drive Pi3k Signaling And Circumvent The Necessity Of Kras-Driven Pi3k Activation In Pdac, Lucas Christopher Bialousow

MUSC Theses and Dissertations

Pancreatic ductal adenocarcinoma (PDAC) has one of the lowest five-year survival rates among cancers and is characterized by near-ubiquitous occurrence of oncogenic KRAS mutations. Oncogenic KRAS activates several downstream pathways, including ERK 1/2 MAPK and PI3K, which are critical for PDAC. However, accumulating evidence suggests that PI3K activity can be maintained independent of oncogenic KRAS. The high prevalence of KRAS^G12R in PDAC challenges the prevailing model of KRAS-driven PI3K activation, as this mutant is defective in direct engagement with PI3Kα. These observations raise important questions regarding how PI3K signaling is sustained in PDAC. Here, we investigated KRAS-independent mechanisms that …

Characterization Of Circulating Extracellular Proteome In Plasma Samples Of Triple-Negative Breast Cancer Patients, Brionna Wilson

Honors Theses

Extracellular vesicles (EVs) are membrane-bound vesicles secreted by cells in the body that play an important role in intercellular signaling, immune modulation, and transfer of biomolecules between cells. EV s reflect the physiological state of their cells of origin, so they are being explored as potential noninvasive biomarkers for cancer detection and monitoring. Triple-negative breast cancer (TNBC), an aggressive subtype lacking targeted therapies, is difficult to detect early and currently has no reliable prognostic biomarkers. This study aimed to quantify EV concentrations in the blood serum of TNBC patients (n=40) compared with cancer-free healthy controls (n=35) as well as determine …

Platelet Gαz Regulates Ovarian Tumor Growth And Mediates The Effects Of Chronic Stress, María G. Torres Carrizalez

Dissertations and Theses (Open Access)

Ovarian cancer is the most aggressive gynecologic cancer, with 12,450 estimated deaths in 2026. Elevated platelet counts are commonly observed in patients with ovarian cancer and are associated with enhanced tumor growth and poor prognosis. Patients with ovarian cancer are frequently exposed to elevated levels of stress, which has been correlated with accelerated disease progression and increased mortality. Interestingly, the platelet Gαz protein is activated by epinephrine through the α2A-adrenergic receptor, suggesting a potential mechanistic link between stress signaling and platelet-driven tumor progression. To investigate this, I evaluated the role of platelet Gαz in ovarian cancer using control (Gz^{fl/fl …}

Human Osteosarcoma Cell Line That Overexpresses Cd4/Ccr5 Or Cd4/Cxcr4 To Study Hiv-Host Interactions, Harry Baffour Awuah

Biotechnology Theses

Human immunodeficiency virus type 1 (HIV-1) entry into host cells occurs through interactions between the viral surface envelope glycoprotein (Env) and the host receptor CD4, and co-receptors CCR5 or CXCR4. However, understanding these interactions in membrane contexts remains limited due to low receptor and coreceptor densities in commonly used cell models. To address this, we developed cellular systems with elevated CD4 expression and either CCR5 or CXCR4. Human osteosarcoma cells (HOS), which lack endogenous surface expression of HIV receptor (CD4) and co-receptors (CCR5 or CXCR4), were engineered via lentiviral transduction to overexpress CD4 and either CCR5 or CXCR4. Cells were …

The Role Of Bacteriophage In The Rgg1-Mediated Virulence Control Of Streptococcus Pyogenes, Yuan Tian

Dissertations and Theses

In Streptococcus pyogenes, bacteriophages and other horizontally transmissible elements (HTEs) comprise approximately 10% of the genome, and each clinical isolate carries a unique combination of these elements, contributing to genetic diversity, virulence, antibiotic resistance, and immune evasion. Previously, our laboratory identified binding sites of the transcriptional regulator Rgg1 in the clinical isolate NZ131 and demonstrated that Rgg1 influences genome-wide gene expression, including bacteriophage genes. In the clinical isolate SF370, the prophage SpyCIM1, positioned in the chromosome between the mutL and mutS genes, controls DNA mismatch repair through excision and reintegration into the chromosome. In the integrated form, the prophage displaces …

Sexually Dimorphic Effects Of Gpnmb Modulation On Vertebral Bone Mass Regulation And Intravertebral Disc Health, Hakem Altawil, Fayez Safadi

Williams Honors College, Honors Research Projects

Osteoporosis and vertebral degeneration are major contributors to musculoskeletal morbidity, yet the molecular mechanisms regulating vertebral bone and intervertebral disc (IVD) homeostasis remain incompletely understood. GPNMB (osteoactivin) has been identified as a regulator of bone remodeling, though its role in spine health is unclear. This study evaluated the effects of GPNMB deficiency on lumbar vertebral bone microarchitecture and IVD integrity in a sex-dependent context.

Six-month-old male and female wild-type (WT) and GPNMB knockout (KO) mice were analyzed using micro–computed tomography (µCT) of lumbar vertebrae (L4–L6) and histological assessment of the L5–L6 IVD. KO males exhibited increased bone volume fraction, bone …

Modulating Ezh2 Activity And Methionine Metabolism To Improve Treatments In Non-Small Cell Lung Cancer, Avery Childress

Theses and Dissertations--Toxicology and Cancer Biology

Non-small cell lung cancer (NSCLC) is currently the leading cause of cancer-related death in the United States. Immunotherapies, such as those targeting the PD1/PD-L1 axis to allow the patient’s own immune cells to target the tumor, have improved outcomes. However, sustained responses are observed in only a fraction of patients. Finding ways to boost immunotherapy responses is the central goal of this project. Many groups are testing additional drugs or dietary intervention to reprogram the tumor and tumor microenvironment (TME) interactions from one that allows tumor growth and resistance to one that has robust anti-tumor immunity. One attractive target for …

Manuka Honey Modulates Oxidative Stress In Neuro2-A Cells Through Mitochondrial Regulation, Rachel Abramovici

Honors Undergraduate Theses

Manuka honey is known for its vital usage in wound healing, being an agonist towards fighting infections, and is an acting antioxidant [32]. Its main constituents are flavonoids and phenolic compounds, with methyl syringate (MSYR) being a major active ingredient. The specific compounds responsible for these antioxidant effects, particularly in the CNS, remain unclear. It is hypothesized that pre-treatment of mouse neuroblastoma cells with MSYR followed by hydrogen peroxide exposure will activate the AMPK/SIRT1/PGC-1a pathway, due to MSYR’s phenolic structure, and thus reduce oxidative stress and improve mitochondrial biogenesis. Hydrogen peroxide is a standard reactive oxygen species (ROS) treatment to …

Exploring Anticholinergic Neurotoxicity: Diphenhydramine's Impact On Neuro-2a Cell Morphology, Expression, And Viability, Jordan B. Mcintyre

Honors Undergraduate Theses

Anticholinergic medications, such as diphenhydramine (commonly known as Benadryl), are increasingly recognized for their association with cognitive impairment and neurodegenerative disease. These medications, which inhibit the action of acetylcholine, a neurotransmitter essential for the formation and utilization of the central and peripheral nervous system, have been implicated in conditions such as dementia and may impact fundamental cellular processes like neurogenesis and cell proliferation. This study investigates the effects of diphenhydramine on neurogenesis when introduced to Neuro-2a cells during differentiation. For all studies cells were plated on coverslips or in 6-well plates with differentiation media containing 0 ng/mL, 50 ng/mL, …

The Influence, Dependency, And Targeting Of Fatty Acid Uptake In Er+ Breast Cancer, Abigail E. Goen

Dartmouth College Ph.D Dissertations

Estrogen Receptor-positive/ Human Epidermal Growth Factor 2-negative, breast cancer (ER+/HER2- BC) is the most prevalent subtype of BC, impacting millions of individuals. Although early screening and treatment with endocrine therapy has greatly enhanced survival, this subtype sustains a steady increase of risk for recurrent disease for decades after diagnosis, indicating the persistence of residual cancer cells that are capable of maintaining dormancy for >20 years prior to metastatic outgrowth. Dormant cells reprogram metabolic pathways which can be profoundly influenced by the tumor microenvironment in promoting quiescence or proliferation. Fatty acid oxidation dependency has been noted as a hallmark of drug …

Fgf19 As A Colorectal Cancer Serum Biomarker And Fgfr4 As A Mediator Of Anti-Her2 Resistance In Breast Cancer, Jordan Beardsley

Graduate Studies Theses and Dissertations 2026

The fibroblast growth factor 19 (FGF19)-fibroblast growth factor receptor 4 (FGFR4) signaling pathway regulates hepatic metabolism, bile acid (BA) synthesis, and hepatocyte proliferation. This signaling axis also is implicated in promoting tumor progression, therapeutic resistance, and metastasis in certain cancers.

In colorectal cancer (CRC) there is a critical need for non-invasive biomarkers for disease detection and monitoring. We identified FGF19 as a candidate CRC serum marker through meta-transcriptomics and found FGF19 to be expressed and secreted by CRC cell lines. Tumor-derived FGF19 was detectable in mouse serum at levels correlating with tumor volume in a subcutaneous xenograft model. RNA sequencing …

Exploring The Role Of Hes4 During Retroviral Infection, Raphael Opoku

Graduate Studies Theses and Dissertations 2026

Human immunodeficiency virus (HIV) infection disrupts immune homeostasis and impairs antiviral defenses, partly by compromising natural killer (NK) cell activity, with simian immunodeficiency virus (SIV) infection in rhesus macaques serving as a valuable model to investigate these mechanisms. This research examines the regulatory role of HES4 and its isoforms in NK cell function during retroviral infection, with particular focus on how Notch signaling–dependent regulation of HES4 shapes NK effector responses. HES4, a downstream effector of the Notch signaling pathway, encodes transcriptional repressors central to immune cell differentiation, yet its contribution to NK cell biology remains poorly understood. Using molecular and …

Investigation On The Effects Of Hypoxia-Mimicking Agents In Cancer Progression And Oxidative Stress In Hepatocellular Carcinoma, June Wong Xin Ni

Student Works (2020-2029)

Hypoxia, or oxygen deprivation, is a common pathological feature found in hepatocellular carcinoma (HCC). Hypoxia-inducible factor (HIF) is the master transcription factor of oxygen homeostasis, eliciting a wide range of cellular adaptive responses to either enhance oxygen delivery or reduce oxygen consumption. HIF is primarily regulated by two types of oxygen sensors, the prolyl hydroxylase domain-containing proteins (PHDs) and factor-inhibiting HIF (FIH). In tumours, HIF functions as a double-edged sword whereby it could either promote or hinder tumour progression. This is mainly contributed by the pleiotropic nature of hypoxia and tumour heterogeneity. Recently, there is a growing interest in the …

Enhancing Preparedness: A Genetic Study Of Sar-Cov-2 And Other Microbial Public Health Threats In Wastewater From A College Town, Christian N. Hutchinson

Master's Theses

Problem

The SARS-CoV-2 (COVID-19) pandemic revealed both the systemic vulnerabilities of our healthcare system as well as the importance of timely, localized data for informing public health responses. Traditional testing approaches were essential but often failed to capture the full extent of viral spread, especially in those with mild or asymptomatic conditions that relied on at home testing. This underreporting hindered effective allocation of resources and made developing effective intervention strategies difficult. We also realized the potential for wastewater surveillance to be applied to tracking antimicrobial resistance gene markers. Taken together, this approach should have important implications for improving public …

Identifying Novel Fibrotic Mechanisms Underlying Treatment-Resistant Lower Urinary Tract Dysfunction, Quentin Darcy

Graduate Doctoral Dissertations

ABSTRACT

IDENTIFYING NOVEL FIBROTIC MECHANISMS UNDERLYING TREATMENT-RESISTANT LOWER URINARY TRACT DYSFUNCTION

August 2025

Quentin D’Arcy, B.S., University of Massachusetts Amherst

Ph.D., University of Massachusetts Boston

Directed by Dr. Jill Macoska

Lower urinary tract dysfunction (LUTD) is a common, age-related disease that affects millions of men over the age of 50. Current treatment for this and other related prostate diseases concentrate on decreasing benign prostate growth and relaxing smooth muscle contractions to alleviate urinary voiding symptoms. However, up to 45% of patients with LUTD are treatment-resistant and require surgical intervention to resolve prostate issues. By focusing on the contribution of inflammation-derived …

Restoring Translational Control With Novel Small Molecule Activators Of Pp2a In Cancer Cells, Kayla A. Jonas

Theses & Dissertations

Hyperactivation of eIF4E-dependent translation in tumor cells is required for robust expression of oncogenic proteins and maintenance of the transformed phenotype. eIF4E binds to the 7-methylguanylate structure at the 5’ end of cellular mRNAs and nucleates the formation of the translation initiation complex, eIF4F, which recruits the preinitiation complex and resolves secondary structure in the mRNA. The ability of eIF4E to promote eIF4F assembly is negatively regulated by the translational repressor, 4E-BP1, and tumorigenesis depends on functional inactivation of 4E-BP1. A major mechanism of 4E-BP1 inactivation involves inhibitory phosphorylation by mTOR which prevents eIF4E binding. Functional inactivation can also occur …

Impact Of Urban Fine Particulate Matter Exposure On Cardiovascular Health, Shelby P. Briggs

Honors Theses

Air pollution, particularly exposure to fine particulate matter (PM2.5), poses a growing threat to cardiopulmonary health. PM2.5 consists of microscopic particles smaller than 2.5 microns in diameter and originates from industrial combustion, transportation, and urban dust. These particles are classified as xenobiotics and are capable of bypassing respiratory defenses to enter systemic circulation, where they cause oxidative stress, inflammation, and cardiovascular dysfunction. This study examines the effects of PM2.5 on cardiovascular function using a murine model. Male C57BL/6 mice were divided into control (saline), subchronic (10 µg), and chronic (100 µg) groups and were exposed weekly for 11 weeks via …

The Influence Of Myocardin Effector Genes On The Tgf-Beta Smad3 Signaling Pathway In Human Pleural Mesothelial Cells, Hema Chandra Hrushi Dusharla

Biotechnology Theses

Pleural Fibrosis (PF) involves excessive extracellular matrix (ECM) deposition, mainly by myofibroblasts, leading to pleural thickening and impaired lung function. Pleural mesothelial cells (PMCs) contribute via mesothelial and mesenchymal transition (MesoMT), triggered by cytokines like TGF-β. Our lab identified Myocardin (MyoCD), a transcriptional co-activator of cardiac and smooth muscle, is a master regulator of pleural fibrosis through interactions with serum response factor (SRF) and Smad2/3 transcription factors which initiate fibrosis signaling. RNA sequencing and qPCR analysis revealed that silencing MyoCD decreased the expression of CTNNB1, MDFI, and Tspan2. MDFI emerged as a potent candidate, as this gene affecting the expression …

Anti-Cancer Activity Of Marine-Derived Fucosylated Chondroitin Sulfates In Ovarian Cancer Cell Spheroid Formation And Notch Signaling Inhibition, Daniella Beiner

Honors Theses

Ovarian cancer is the deadliest gynecological malignancy, with high recurrence rates driven by chemotherapy-resistant cancer stem cells (CSCs). Current therapeutics targeting Notch signaling to inhibit CSC formation have yet to demonstrate clinical benefit and pose risk of gastrointestinal toxicities. Here, we report that treatment with fucosylated chondroitin sulfates (FucCS) inhibited Notch signaling activation and spheroid formation in OVCAR3 ovarian cancer cells. Sulfation and fucosylation were shown to be key structural requirements of this anti-cancer activity. Moreover, this inhibition was synergistic with suppression of Notch glycosylation by Radical Fringe knockout. Preliminary experiments to conjugate FucCS to a maleimide linker in preparation …

Novel Combination Therapies For Estrogen Receptor-Positive Breast Cancer Driven By Rational Molecular Mechanisms, Anneka Lila Johnson

Dartmouth College Ph.D Dissertations

Breast cancer (BC) is the most common non-keratinocyte cancer diagnosed in women in the United States with approximately 300,000 new cases diagnosed each year. Despite a myriad of treatment options, BC remains the second-most deadly cancer. Estrogen receptor-positive (ER+) BC comprises 60-70% of BC diagnoses and is treated with endocrine therapies that limit ER signaling. Despite endocrine therapy options, ~1/3 of patients experience recurrence within 10-20 years of diagnosis. Novel therapeutic strategies are required to limit BC recurrence-related morbidity and mortality.

Radiotherapy is used as an adjuvant treatment for ER+ BC patients prior to the use of endocrine therapy. Radiation …

Pseudomonas Aeruginosa Exoenzyme Y Enzymatic Activity Inhibits Exoenzyme S-Induced Caspase Activation But Not Cytotoxicity In Pulmonary Microvascular Endothelial Cells, Connor Holm

Honors Theses

Pseudomonas aeruginosa (P. aeruginosa) is the most common cause of ventilator-associated pneumonia in intensive care unit patients. P. aeruginosa utilizes a type III secretion system that injects exoenzymes U, S, T, and/or Y into the host cell cytosol. A majority of clinically isolated P. aeruginosa strains express ExoY often in combination with ExoU and ExoT, or ExoS and ExoT. Host signaling mechanisms in response to intoxication with individual exoenzymes have been extensively studied, yet little is known about host cell response to co-intoxication. In this study, pulmonary microvascular endothelial cells (PMVECs) were infected with P. aeruginosa strains expressing different combinations …

Developing A Small Molecule To Inhibit Hsf1 Expression In Cancer And Evaluating Natural Genetic Variation In Small Molecule Toxicity., Michaela Kendal Foley

Theses and Dissertations

Each year cancer affects nearly 20 million people worldwide and genetic differences across populations can impact cancer onset and progression. Specifically, tumors with high levels of HSF1, the master regulator of the cytoprotective heat shock response (HSR), are correlated with poor patient outcomes in multiple cancers such as prostate, breast, and melanoma. Subsequently, the development of pharmacological inhibitors of HSF1 represents a promising strategy for anticancer therapeutics. Using a luciferase-based transcriptional reporter, two small molecule libraries were screened for inhibitors of HSF1 expression in human embryonic kidney cells, yielding ten compounds that decrease HSF1 expression. To identify if cancer lines …

A Long Non-Coding Erna Forms R-Loops To Shape Emotional Experience-Induced Behavioral Adaptations, Rose Marie Akiki

MUSC Theses and Dissertations

Emotional experiences often evoke neural plasticity that supports adaptive changes in behavior, including maladaptive plasticity associated with mood and substance use disorders. These adaptations are supported in part by experience-dependent activation of immediate-early response genes, such as Npas4. We discovered that a conserved, long non-coding enhancer RNA (lnc-eRNA) transcribed from an activity-sensitive enhancer produces DNA-RNA hybrid R-loop structures that support 3D chromatin-looping of the enhancer and proximal promoter and stimulus-induced, rapid Npas4 gene induction. We also show that this Npas4 lnceRNA and its R-loops are required for the development of behavioral adaptations produced by chronic psychosocial stress or cocaine exposure, …

Mir-125a-3p And Its Targets: Promising Biomarkers For Ovarian, Liver, And Breast Cancers, Offering A Beacon Of Hope For More Effective Diagnosis And Treatment Strategies, Eman Kamaleldien Anwer

Theses and Dissertations

Cancer is a worldwide health problem with various genetic and epigenetic alterations, resulting in disease heterogeneity. Effective diagnostic, therapeutic, and monitoring markers have been determined recently; however, new diagnostic, prognostic, and therapeutic markers are needed. MicroRNAs (miRNA), short non-coding RNAs, have a highlighted role in cancer progression, migration, and programmed cell death. Our study aims to investigate the significance of miR-125a-3p and its downstream targets in breast (BRCA), hepatocellular (HCC), and ovarian (OVCA) malignancies and their possibility as diagnostic biomarkers and targets for therapeutic agents. Bioinformatics and online tools were used to determine the miRNA-predicted downstream targets, analyze GEO datasets, …

The Effect Of Hypochlorous Acid On Cultured Osteoblast And Escherichia Coli, Cristina Flaquer Fusté

Graduate Theses/Dissertations

Hypochlorous acid (HOCl), a naturally occurring compound in neutrophils, has been used as an antimicrobial in wound treatment. Osteoblasts, bone-forming cells, within the bone tissue play a large role in bone fracture healing. Orthopedic infections are challenging to treat and highly morbid, including surgical site infection of arthroplasty procedures or infection in the setting of compound fractures. HOCl is being considered as a surgical antiseptic to decrease infections in orthopedic surgical procedures. This study therefore seeks to determine the effects of HOCl on osteoblasts and E. coli. Cultured osteoblasts were incubated with varying concentrations of HOCl to examine osteoblast …

Targeting Prmt5 In Inflammation And Cancer: A Nexus Of Endotoxin Signaling, Antigen Presentation And Immune Evasion., Jimmy James Msemo

Theses and Dissertations--Medical Sciences

Protein Arginine Methyltransferase 5 (PRMT5) is a member of PRMT family that controls both intrinsic and extrinsic oncogenic processes [1]. Protein arginine methyltransferase 5 (PRMT5) is a type II methyltransferase that exerts widespread influence over gene expression, splicing, DNA repair, and immune regulation through symmetric dimethylation of arginine residues on histone and non-histone proteins [2]. The addition of methyl groups induces gene silencing through producing dictatorial histone marks like H2AR3ne2s, H3R8me2s and H4R3mes [3], which act as epigenetic repressive marks on gene promoters. In non-histone proteins, PRMT5 can methylate and regulate transcription factor proteins such as p53, E2F1, and p65, …

Investigating Regulation And The Regulome Of The Nucleic Acid Binding Protein Spovg Within Borrelia Burgdorferi, Timothy C. Saylor

Theses and Dissertations--Medical Sciences

Prior studies indicated Borrelia burgdorferi SpoVG protein was regulated, SpoVG binds specifically to a number of nucleic acids, and SpoVG binds to the non-variable section of the major virulence factor vlsE. Although a direct transcriptional activator or inhibitor was not elucidated, it is shown that SpoVG is regulated based on cell culture density independent of the growth rate of B. burgdorferi, indicating that SpoVG regulation is outside the scope of the alternative sigma factor RpoS. Using a dCas9 CRISPRi construct to target SpoVG resulted in protein expression trending towards upregulation of the BosR-RpoS regulon, and a marked decrease …

Investigating The Role Of Prostasin In Angiogenesis: A Chorioallantoic Membrane Model Approach, Zaima Aline

Honors Undergraduate Theses

Prostasin, also known as PRSS8 or CAP1, is a glycosylphosphatidylinositol (GPI)-anchored extracellular serine protease involved in various physiological and pathophysiological processes. Prostasin expression is observed during key phases of trophoblast invasion and placental development, critical steps in embryo implantation in Rhesus monkeys. This suggests a role for prostasin in extracellular matrix remodeling and tissue invasion, both essential for a healthy pregnancy. Moreover, prostasin appears vital for development as studies in mice show that a germline knockout of the gene leads to significant placental defects and eventual embryonic death, highlighting its importance in vascular and structural development within the placenta.

Building …

Facilitation Of Chemotherapy Efficacy Through Targeted Drug Delivery In Lung Cancer Cells Via Ultrasound And Implications On Health Interventions, Ibrahim Nasim

Honors Undergraduate Theses

Lung Cancer (small cell and non-small cell) is the leading cause of cancer death in the US, accounting for about 20% of all cancer deaths. Paclitaxel (PTX) is a chemotherapeutic agent commonly used to treat lung cancer. It works by slowing and stopping cancer growth by stiffening microtubules within cells, promoting mitotic halt and cell death. Carboplatin (CP) is another agent given to lung cancer patients containing platinum and works via direct damage of oncolytic DNA. The exact mechanism of how PTX and CP cause cell death is still an under-studied area. This thesis aims to provide insight into how …

Astrocyte Specific Enhancers In The Cortex And Striatum Of Mice, Mikaela Kottelich

Williams Honors College, Honors Research Projects

Among glial cells, astrocytes have a prevalent influence on supporting neuronal function and overall brain health. Specifically targeting this cell type for disease treatment is an existing issue. Other cell types tend to express the desired treatment, which is not always wanted and can lead to unintended, negative consequences. Astrocytes contribute largely to maintaining the blood brain barrier, which is disrupted in Parkinson’s disease. Certain genes are thought to be the reason for this disruption, so if they can be specifically targeted in astrocytes with a specific enhancer, the disruption of the disease could be reversed. In our experiment, we …