Cell and Developmental Biology Commons^™

Mechanistic Insight Of Neuropilin-2 Expression During The Progression Of Prostate Cancer, Sanika Bodas

Theses & Dissertations

Advanced prostate cancer represents a particularly aggressive and challenging form of prostate cancer (PCa) that shows resistance to both traditional therapies, such as androgen deprivation therapy, and newer treatment modalities like hormone therapies and immunotherapies. For patients diagnosed with advanced stages of PCa, treatment options are limited, and chemotherapy is often the last line of defense. Unfortunately, chemotherapy can severely diminish the quality of life, particularly in older patients, due to its harsh side effects, including fatigue, immune suppression, and overall physical decline. Despite these challenges, researchers and clinicians remain focused on developing more effective and targeted treatments for patients …

Development Of Self-Assembled Polymeric Polyplexes For Microrna Delivery: Toward Treatment Of Alcohol-Associated Liver Disease, Marjina Akter Kalpana

Theses & Dissertations

Self-assembled polymeric polyplexes have the potential to serve as an RNA interference (RNAi) delivery platform for the combined inhibition of CXCR4 and miR-155 in the treatment of alcohol-associated liver disease (AALD). A central challenge in RNA delivery is balancing the extracellular stability of polyplexes, cellular uptake, and intracellular release of RNA cargo. We developed polymeric polyplexes using the CXCR4-antagonist polymer PAMD, designed to target CXCR4 on activated hepatic stellate cells (HSCs) and deliver therapeutic miRNA to activated Kupffer cells (KCs) in fibrotic liver. We improved the polyplexes by cholesterol modification of PAMD and by PEGylation of PAMD-Ch. The cholesterol modification …

Role Of Stabilin-1 Expressing Macrophages In Colorectal Liver Metastasis, Jampa L. Gurung

Theses & Dissertations

Colorectal cancer (CRC) is the 2nd most common cause of cancer-related mortality, primarily due to its spread to distant organs. Colorectal liver metastasis (CRLM) is the foremost form of CRC spread due to the anatomical link between the liver and intestine. Despite advancements in diagnostic tools and adjuvant therapies, the survival rate of CRLM remains low, indicating the significant need to identify targetable mechanisms. Stabilin-1 (STAB1), a scavenger receptor expressed on tumor-associated macrophages, has been linked to tumorigenesis and poor outcomes in various cancers. However, the role of STAB1 in CRLM is not known. Here, we investigated the role of …

Kinase Suppressor Of Ras 2 Regulates Energy Balance And Tumor Initiation, Dianna H. Huisman

Theses & Dissertations

Kinase Suppressor of Ras 2 (KSR2) is a scaffold that facilitates Raf-MEK-ERK signaling and is expressed in the brain, pituitary, and adrenal gland. Here, we demonstrate that KSR2 functions in the adult brain to maintain organismal energy balance and in small-cell lung carcinoma (SCLC) to promote self-renewal and clonogenicity. Disruption of KSR2 in adult mice results in hyperphagia, obesity, reduced metabolic rate, and altered activity. Using spatial transcriptomics, we identify regions of the brain associated with regulation of feeding and energy expenditure with altered gene expression following KSR2 disruption. These findings reveal regions of interest in which targeted KSR2 disruption …

Claudin-1-Mediated Signaling And Therapy Resistance In Colorectal Cancer: From Mechanism To Translation, Mark W. Primeaux

Theses & Dissertations

Colorectal cancer (CRC) remains a leading cause of cancer-related mortality, with metastatic cases showing poor response to chemotherapy due to both intrinsic and acquired therapy resistance. Claudin-1 (CLDN1), a tight junction protein, is overexpressed and mislocalized outside of tight junctions in CRC, where it contributes to an aggressive, metastatic phenotype. Although this causal relationship has been well established, the mechanisms by which CLDN1 promotes tumor progression were unclear due to its lack of intrinsic enzymatic activity. This dissertation investigates the molecular mechanisms through which CLDN1 drives oncogenic signaling, its role in therapy resistance, and its translational potential as both a …

Drivers And Mechanisms Of Golgi Fragmentation As A Modulator Of Disease, Amanda Macke

Theses & Dissertations

The Golgi apparatus plays a pivotal role in post-translational modification, trafficking, and secretion of proteins, ensuring proper cellular function. As a result, its fragmentation has been implicated in multiple pathological conditions, including alcohol-induced liver injury and prostate cancer (PCa). Despite its known impact on cellular homeostasis, the molecular mechanisms governing Golgi fragmentation remain to be clarified. Additionally, we have only just begun to understand the vast consequences of Golgi disorganization on disease progression.

This dissertation investigates the drivers and mechanisms of Golgi fragmentation, with a focus on its role as a modulator of disease. Using both in vitro and in …

Cholestasis And Fluid Flow Are Biomechanic Regulators Of Cholangiocarcinoma Progression, Andrew Oleksijew

Theses & Dissertations

Cholestasis, altered or absent bile flow, is associated with poor survival in patients with cholangiocarcinoma, an aggressive cancer of the biliary epithelium. Changes in bile flow often result in stricture or obstruction. Experimental cholestasis promoted tumor growth and progression. However, studies are needed that directly assess the mechanical interaction between bile flow, or bile shear stress, and cholangiocarcinoma signaling. We hypothesized that cholestasis and absent bile shear stress activated cancer signaling and increased aggressive cellular behaviors such as proliferation and migration. Fluid shear stress approximating bile flow was applied by orbital culture plate method and compared to identical static culture …

Validating The Ability Of Iag933 To Block The Interaction Of Yap1 And Tead In Ovarian Cancer Cells, Alex Sage

Theses & Dissertations

Ovarian cancer is the most common and deadliest gynecologic malignancy. Approximately 40% of ovarian cancer patients exhibit chemoresistance after receiving initial treatment in the form of neoadjuvant chemotherapy or interval debulking surgery, of which YAP1 (Yes-associated protein 1) has been implicated in enhancing the resistance of ovarian cancer to Cisplatin and Taxol.^1,2. This highlights the need to develop new therapeutic strategies that target the Hippo pathway to overcome resistance to traditional therapies.

YAP1 is a protein that acts as a transcription coregulator, promoting the transcription of genes involved in cellular proliferation and suppressing apoptotic genes. It is a …

Coxiella Burnetii Manipulation Of Membrane Contact Sites In The Intracellular Niche, Margaret F. Sladek

Theses & Dissertations

Coxiella burnetii is a highly infectious and environmentally persistent bacterium that causes the disease Q Fever. Its intracellular home, the Coxiella-Containing Vacuole (CVV), is formed from fusion of host-derived vesicles and is rich in sterols - yet cholesterol accumulation in the CCV is bacteriolytic. Our lab’s goal is to understand how Coxiella manages intracellular cholesterol levels and survives within the host. One way Coxiella may modulate CCV cholesterol is through membrane contact sites (MCS), areas where molecular complexes bridge two organelles and exchange lipids. This thesis explores how Coxiella uses both a mammalian lipid transfer protein and bacterially-encoded effector …

P85Α Degradation Mediated By Ubiquitin E3 Ligase Fbxo21 Offers Therapeutic Potential In Leukemia, Kasidy K. Weber

Theses & Dissertations

Acute myeloid leukemia (AML) is a complex and heterogeneous disease characterized by the clonal expansion of myeloid blasts in the bone marrow. Despite significant therapeutic advances over the years, the prognosis for AML patients remains dismal, with high relapse rates and poor overall survival. The ubiquitin-proteasome system (UPS) plays a critical role in maintaining cellular homeostasis by regulating the degradation of proteins involved in essential processes such as cell cycle control, DNA repair, apoptosis, and various signaling pathways. Given this vital function, targeting ubiquitin E3 ligases within the UPS presents a promising strategy for developing more effective and targeted therapies …

Dying Right: Supporting Anti-Cancer Therapy Through Immunogenic Cell Death, Elizabeth Schmitz

Theses & Dissertations

The primary goal of most anti-cancer therapy is to eradicate neoplastic cells. Simultaneously, neoplastic cell death is the first step of the cancer-immunity cycle, which starts with the release of antigens from cancer cells and ends with T-cell directed killing of cancer cells, in addition to long-standing memory to tumor antigens encountered. Immunogenic damage-associated-molecular patterns (DAMPs) are endogenous cell molecules repurposed in times of insurmountable cell stress (e.g., CALR, ATP, HMGB1) to facilitate communication between dying cells and adaptive immune cells, acting as adjuvants for the cancer-immunity cycle, in a cellular fate termed immunogenic cell death (ICD). It …

Chemotherapy-Induced Modulation Of Tumor Antigen Presentation, Alaina C. Larson

Theses & Dissertations

Pancreatic cancer is a lethal malignancy, with a five-year overall survival rate of just 13%. Current treatment approaches thus require modification and attention has shifted towards improving immunotherapy efficacy. Select chemotherapy drugs possess inherent immunomodulatory activity and could be used to initiate immunotherapeutic success, thereby restoring anti-tumor immunity in pancreatic cancer. In this work, I evaluated the impact of the chemotherapy drug gemcitabine on tumor antigen presentation by human leukocyte antigen class I (HLA-I). Gemcitabine regulated HLA-I expression on multiple levels, increasing pancreatic cancer cells’ HLA-I mRNA transcripts, total protein and surface expression, as well as surface stability. Temperature-dependent assay …

Targeting Ksr1 To Inhibit Stemness And Therapy Resistance, Heidi M. Vieira

Theses & Dissertations

Tumor heterogeneity is an important contributor to therapy resistance and relapse. Within the tumor, there are subpopulations of tumorigenic, self-renewing cells with enhanced clonogenicity and chemoresistance, termed tumor-initiating cells (TICs). Despite their importance in treatment response, there are no effective therapies to target TICs in solid tumors.

This study identifies a novel role for Kinase Suppressor of Ras 1 (KSR1) in regulating TICs and therapy resistance in Ras-driven cancers. KSR1 is a molecular scaffold in the Raf/MEK/ERK kinase cascade downstream of Ras. KSR1 is necessary for Ras-mediated transformation, but dispensable for normal cell growth; further, ksr1^-/- mice are phenotypically …

Cis-Regulatory Mechanisms Through Stages Of Erythroid Regenration, Yichao Zhou

Theses & Dissertations

Produced by steady state erythropoiesis, erythrocytes serve as vital regulators of metabolism and life by delivering oxygen to all the cells and tissues. Under acute anemia, steady state erythropoiesis is not sufficient to produce enough erythrocytes, leading to distinct mechanisms needed to regenerate large numbers of mature erythrocytes rapidly. Erythroid regeneration occurs in four stages: activation, expansion and differentiation, resolution, and post-resolution, according to the dynamics of erythrocyte numbers and progenitor activity. Erythroid regeneration throughout this timeline requires some critical extracellular cues, but the intrinsic molecular mechanisms needed to accelerate and decelerate the activity of erythroid progenitors in anemia and …

Targeting Lifr/C-Myc/Ddx21 Axis To Overcome Docetaxel Resistance In Prostate Cancer, Sushanta Halder

Theses & Dissertations

Resistance to chemotherapy poses a significant challenge in the treatment of advanced-stage prostate cancer (PCa), specifically with chemotherapy drugs like docetaxel (Doce), which is often employed after the failure of hormone therapy. However, 50-90% of PCa patients develop resistance to docetaxel within three years of post-chemo treatment, compounded by serious adverse side effects necessitating dose reductions. Various strategies are being investigated to address this issue, including identifying new therapeutic targets or mechanisms, developing novel combination therapies, and optimizing dosing regimens. In particular, our research is focused on uncovering the underlying mechanisms of resistance to docetaxel, such as the activation of …

Identifying The Molecular Determinants Of Lung Metastatic Adaptation In Prostate Cancer, Grace M. Waldron

Theses & Dissertations

Prostate cancer (PC) stands as the primary diagnosed cancer in men in the US at approximately 299,010 cases in 2024 and ranks second globally, posing a significant public health challenge. Clinical presentations vary widely, from indolent to aggressive forms, necessitating stage-specific treatment regimens. Understanding its metastatic nature is critical due to the impact of cancer cell dissemination on disease morbidity, with bone and visceral organs serving as key sites of metastasis. Despite bone metastasis being the most common site for metastasis, visceral metastases at sites such as the liver and lungs correlate with poorer survival, emphasizing the role of microenvironmental …

Identification Of Mitotic Phosphatases And Cyclin K As Novel Molecular Targets In Pancreatic Cancer, Yi Xiao

Theses & Dissertations

Pancreatic cancer is a highly lethal disease worldwide. Given the limited effectiveness of current regimens in restricting tumor progression, it is imperative that potential molecular targets be identified to offer valuable insights into alternative therapeutics. By using a phosphate-binding tag (Phos-tag) technique, previous studies have identified several Hippo pathway-related proteins and kinases required for cancer growth or paclitaxel resistance. This work has screened various phosphatases and cyclins/cyclin-dependent kinases (CDKs) as potential cancer targets, but specifically focuses on characterizing the roles of carboxy-terminal domain small phosphatase like 2 (CTDSPL2), apoptosis-stimulating protein of p53-2 (ASPP2), and Cyclin K in pancreatic cancer.

CTDSPL2 …

Therapeutic Effects Of Bet Protein Inhibition In B-Cell Malignancies And Beyond, Audrey L. Smith

Theses & Dissertations

Chronic lymphocytic leukemia (CLL) develops through a combination of intrinsic genetic defects, constitutively active survival/proliferation signaling pathways, and complex microenvironment interactions. Redundant tumor microenvironment (TME) immuno-suppressive mechanisms and epigenetic maintenance of terminal T-cell dysfunction also greatly hinder anti-tumor T-cell responses in CLL. Small-molecule agents targeting the B-cell receptor (BCR) pathway and anti-apoptotic proteins alone or in combination with chemo-immunotherapy have revolutionized the management of CLL, yet there is still a significant need for novel therapeutic strategies to yield durable tumor elimination. Bromodomain and extra-terminal domain (BET) proteins are epigenetic readers that bind to acetyl-lysine residues on histones to regulate gene …

Homeobox A10: Regulator Of Pancreatic Cancer Progression And Survival, Sophia G. Kisling

Theses & Dissertations

Pancreatic ductal adenocarcinoma (PDAC) has one of the lowest incidence rates among all major cancers, yet it is disproportionally responsible for 8% of all cancer deaths. This high death rate is primarily attributed to the immunosuppressive tumor microenvironment and a lack of clinically relevant molecular targets. However, the underlying biology responsible for these poor outcomes remains obscure. To facilitate improved management of PDAC, an in-depth understanding of the molecular player(s) involved in PDAC aggressiveness is needed. Therefore, we analyzed the transcriptomic profiles of PDAC patients with long- and short-term survival and performed gene set enrichment analysis (GSEA), identifying a novel …

Mucins: Drivers Of Cancer Cell And Microenvironment Crosstalk In Pancreatic Cancer, Xiaoqi Li

Theses & Dissertations

Mucins facilitate the pancreatic cancer (PC) initiation, progression, and metastasis. Among mucins, MUC4 has been reported to inhibit lymphokine-activated cell killing and induce the apoptosis of cytotoxic T-cells. Counterintuitively, MUC4 expression is upregulated by multiple T-cell-secreted cytokines, such as IFN-γ, IL-17, and stroma-secreted factors like retinoic acid. Previously, we have identified that nuclear receptor coactivator 3 (NCOA3) regulates the MUC1 and MUC4 expression by increasing chromatin accessibility and maintaining protein stability. However, the comprehensive crosstalk mediated by MUC4 in cancer cells and T-cells and how its upstream regulator, NCOA3, modifies the cancer cell-intrinsic behavior is still elusive. Here, we show …

Novel Spirocyclic Dimer (Spid3) Displays Potent Preclinical Effects In Hematological Malignancies, Alexandria Eiken

Theses & Dissertations

Chronic lymphocytic leukemia (CLL) is a heterogeneous disease characterized by the accumulation of mature CD5⁺ B-cells in the peripheral blood, bone marrow, and secondary lymphoid tissues (e.g., spleen and lymph nodes).Despite the efficacy of front-line therapies, CLL is still an incurable disease, highlighting the need for development of novel therapeutics and further study of resistance mechanisms. Within the lymph node CLL tumor microenvironment (TME), there is an upregulation of gene signatures associated with B-cell receptor (BCR) and downstream nuclear factor kappa B (NF-κB) signaling compared to CLL cells found within the blood or bone marrow niches. Additionally, BCR signaling …

Characterization Of Trafficking And Metabolic Functions Of The Endocytic Regulator Ehd1 In Ewing Sarcoma, Sukanya Chakraborty

Theses & Dissertations

Ewing sarcoma (EWS) is the second most common bone malignancy in children and adolescents. Despite improvement in survival due to advances in multimodality treatment strategies, patients with metastatic or recurrent disease have very poor outcomes. Overexpression of the EPS15 Homology Domain containing 1 (EHD1) protein has been linked to tumorigenesis but whether its core function as a regulator of intracellular traffic of cell surface receptors plays a role in oncogenesis remains unknown.

Studies presented in this dissertation establish that EHD1 overexpression is a feature of nearly 90% EWS patient tumors with high EHD1 expression specifying shorter patient survival. ShRNA-knockdown and …

Role Of The Ganglioside Gd2 And Its Biosynthetic Enzyme Gd3 Synthase In Prostate Cancer Tumorigenesis, Aaqib Bhat

Theses & Dissertations

Despite significant advancements in managing localized prostate cancer (PC), which have notably increased survival rates, advanced PC continues to be a leading cause of cancer- related fatalities. The discovery of new pathways that can be targeted to inhibit tumor growth in PC could pave the way for innovative treatment strategies. The disialylganglioside GD2 is an FDA-approved target for antibody therapies in neuroblastoma and has not been extensively studied in the context of PC. The work done in this thesis reveals that GD2 is present on a minor subset of PC cells in certain patients and is more prevalent in metastatic …

Synergetic Signaling Between The Chlamydia Secreted Effectors Tarp And Tmea Regulates Actin Kinetics And Efficient Entry, Matthew Romero

Theses & Dissertations

Chlamydia trachomatis is both the leading cause of non-congenital preventable blindness in developing nations and the leading source of bacterial sexually transmitted infections. As an obligate intracellular pathogen, Chlamydia has an absolute requirement on gaining entry into its host, which is accomplished by manipulating the host actin cytoskeleton to assemble engulfment structures that drive pathogen entry. In support of this, Chlamydia secretes the effectors TarP and TmeA via a type-III secretion system, whose respective signaling outputs operate synergistically to generate rapid actin kinetics and efficient pathogen engulfment. Rapid actin recruitment characteristic of invading Chlamydia is derived from a collaborative interaction …

Dynamics Of Site Search Process And Formation Of Synaptosome Assembly Characterized By Single Molecule Approaches, Sridhar Vemulapalli

Theses & Dissertations

Genome dynamics and integrity are the two crucial features defining the successful functioning of cells and their maintenance and evolution. The genetic processes in the cell require distant communications between the regulatory regions controlled by specific proteins. Mistakes in this interaction process will lead to termination of the genetic process may lead to the cell damage, disease development or the cell death. Similar distant regulatory process is required for numerous genome integration systems such as Variable Diversity Joining (V(D)J) recombination system resulting in the specificity of the immunoresponse, a defining property of the adaptive immune system. A common feature of …

Samd14 Mechanisms In Stress Erythropoiesis, Suhita Ray

Theses & Dissertations

Red blood cells (RBCs) essential for tissue oxygenation are generated by the process of erythropoiesis. Any decrease in the RBCs or the oxygen-carrying molecule hemoglobin leads to anemia, affecting nearly 1.62 billion people worldwide. Stress erythropoiesis describes the process of accelerating RBC production during anemia, to compensate for the loss. Among several important mediators of stress erythropoiesis, paracrine signals - involving cooperation between Stem Cell Factor (SCF)/Kit signaling and other signaling inputs – are required for the activation/function of a unique population of progenitor cells - stress erythroid progenitors (SEPs). Biological mechanisms controlling SEP activation and function can be distinct …

The Co-Oncogenic Function Of Ecdysoneless Protein With Erbb2 In Mammary Epithelial Cells, Benjamin B. Kennedy

Theses & Dissertations

The Ecdysoneless (ECD) protein is highly evolutionarily conserved and ubiquitously expressed across human tissues. ECD has established roles in cell cycle regulation, embryogenesis, cell survival, and RNA biogenesis. ECD mRNA and protein are overexpressed in breast cancer, and its overexpression correlates with poor patient survival, especially in ErbB2/HER2-positive breast cancer. This thesis work investigates the co-oncogenic role of ECD in ErbB2-driven oncogenesis using immortalized mammary epithelial cells. Here, we show that ECD and ErbB2 overexpression in immortalized human mammary epithelial cells increases cancer traits, such as invasion, migration, and anchorage independent growth. Significantly, ECD+ErbB2 co-overexpression further enhanced all oncogenic traits. …

Growth Plate Cartilage: Understanding The Contribution Of Adhesion To Column Formation And Matrix Structure, Sydney E. Greer

Theses & Dissertations

Throughout fetal and adolescent development, bone growth is regulated by fine-tuned and controlled maturation of chondrocytes through a cartilaginous template called the growth plate. Bone growth rate is controlled through cell enlargement and extracellular matrix deposition, while the polarized arrangement of proliferative chondrocytes into columns aligned with the long axis of the bone potentiate growth. Chondrocytes are surrounded by a complex three-dimensional arrangement of matrix molecules, all of which are secreted by chondrocytes and assembled/remodeled to support the biological functions of the cell. Adhesion receptors found on the cell membrane of chondrocytes are crucial to the organization of matrix proteins …

Development Of Combination Therapy Strategies To Treat Cancer Using Dihydroorotate Dehydrogenase Inhibitors, Nicholas Mullen

Theses & Dissertations

Cancer cells require supraphysiologic levels of nucleotide triphosphates to fuel their malignant behaviors, including uncontrolled proliferation, immune evasion, metastasis, and therapy resistance. This requirement is met by hyperactive flux through the de novo pyrimidine and de novo purine pathways. Dihydroorotate dehydrogenase (DHODH) is an essential enzyme in the de novo pyrimidine pathway that can be targeted by FDA approved and experimental drug compounds. A robust body of preclinical evidence, encompassing hundreds of independent studies over several decades, demonstrates impressive activity of DHODH inhibitors in animal models of cancer. Paradoxically, however, all clinical trials to date have failed to demonstrate efficacy …

Targeting The Cxcr1/2 Axis In Pancreatic Ductal Adenocarcinoma, Caitlin Molczyk

Theses & Dissertations

Pancreatic ductal adenocarcinoma (PDAC) is notoriously challenging to diagnose and treat. This tumor has an aggressive phenotype and benign clinical features until severe disease dissemination, which makes it too late to eradicate. Although it is only the 10th most common cancer in the United States, it is the fourth leading cause of cancer-related deaths. The treatment options are complicated further due to tumor heterogeneity, meaning not all tumor cells are in the same state phenotypically or epigenetically. They also express cytokines, chemokines, and receptors differently. Here we explore the usage of CXCR1 and CXCR2 and their ligands in PDAC tumor …