Cell and Developmental Biology Commons^™

Impact Of Targeting Glycosylated Ceramides On Tumorigenic Properties, And Characterization Of Sphingolipids In Head And Neck Tumors, Katherine E. Hylton

Theses and Dissertations

Sphingolipids play a crucial role in signaling, membrane structure, and migration, making them important molecules in cancer development, metastasis, and drug resistance. While some sphingolipids have been associated with pro-apoptotic or pro-survival behaviors, the role of many sphingolipids in cancer remains poorly defined. Chapter 1 of this study investigated the impact of three enzymes that compose most of the ceramide to Lc3 ceramide pathway – UGCG, GBA, and B3GNT5 – and how their alteration impacts chemoresistance and basal membrane invasion in vitro. It was found that the CΒE-induced inhibition of GBA, which converts glucosylceramide to ceramide, has no effects on …

The Role Of Autophagy And Senescence In The Responses Of Non-Small Cell Lung Cancer Cells To Chemotherapy And Radiation, Nipa H. Patel

Theses and Dissertations

Cancer-associated deaths account for the second-highest mortality rates in the United States. Primary modalities of treatment often include surgery, radiation, and chemotherapy, and may also incorporate targeted therapy and immunotherapy. However, resistance to these treatments remains high, resulting in disease reoccurrence and poor survival rates. While apoptosis or cell death of tumor cells is the ideal outcome for anti-cancer therapy, this is often not the case, and in fact cancer cells may upregulate several pathways, such as autophagy and senescence, as a means to undergo alternative cell fate and evade apoptotic cell death. An essential tumor suppressor gene, TP53, …

Regulation Of Osseous Healing By Macrophage-Derived Wnt Ligands, Jefferson Overlin Abaricia

Theses and Dissertations

Osseous healing is regulated by various classes of cells and signaling mechanisms. Of these, Wnt signaling has long been known to be critically important in directing the differentiation of mesenchymal stem cells (MSCs) into osteoblasts during bone healing. However, the source of these Wnt ligands is not known. Recently, a body of literature has arisen finding both beneficial and detrimental effects of macrophage-derived Wnt ligands on the regeneration of other tissues (liver, kidney, heart, and intestine), often by regulating inflammatory activation and stem cell behavior. As macrophages have been well-characterized as orchestrators of healing, their use of Wnt signaling to …

The Therapeutic Potential Of Glycosaminoglycan Directed Metalloglycomics: Elucidating New Targets And Mechanisms For Polynuclear Platinum Complexes, James D. Hampton

Theses and Dissertations

Cancer remains a serious clinical problem and in order to continue to improve patient health outcomes, novel treatment strategies must continue to be developed. Platinum chemotherapies remain as one of the most widely successful classes of cancer therapeutic, with over 50% of cancer patients receiving a platinate at some point over the span of their treatment. However, intrinsic and extrinsic resistances limit their effectiveness, long term efficacy, and broad applicability to multiple cancer subtypes. Therefore, the development of new agents and strategies which can overcome these limitations are crucial for patient health. To this end a novel class of polynuclear …

A Mechanism Behind The Mechanotransduction Of Surface Characteristics In Osteoblasts, Otto J. Juhl Iv

Theses and Dissertations

Biomaterials for use in bone regeneration and healing range from metal and metal alloy implants to hydrogel-based solutions. These materials can be optimized to increase bone healing and integration by improving the mechanical and biological properties. Regardless of the material itself, the cell-substrate interaction is key to the success of the biomaterial once implanted. Substrate surface characteristics such as roughness, wettability, and particle density are well-known contributors to a substrate’s overall osteogenic potential, and therefore the substrate's overall success. Unfortunately, it is still unknown how these substrate surface characteristics are transduced into intracellular signals by cells, preventing specific tailoring of …

Microrna In The Mammalian Growth Plate: Matrix Vesicles And 1Α,25-Dihydroxyvitamin D3, Niels C. Asmussen

Theses and Dissertations

Growth plate chondrocytes are the driving force of long bone elongation and they accomplish this vital task, in part, by producing, remodeling, and finally mineralizing the cartilage tissue that makes up the growth plate. This mineralized tissue is turned over again as bone forming cells invade and began the process of turning mineralized cartilage into bone. Chondrocytes undergo a distinct series of observable phases as they move through this process transitioning from a stage of proliferation to one of hypertrophy and finally capillary invasion. Chondrocytes produce matrix vesicles (MVs) that they release into the growth plate and that attach to …

Prolactin Drives A Dynamic Stat5a/Hdac6/Hmgn2 Cis-Regulatory Landscape Exploitable In Er+ Breast Cancer, Justin M. Craig

Theses and Dissertations

The hormone prolactin has been implicated in breast cancer pathogenesis and regulates chromatin engagement by the transcription factor, STAT5A. STAT5A is known to inducibly bind promoters and cis-regulatory elements genome-wide, though the mechanisms by which it exerts specificity and regulation of target gene expression remain enigmatic. We previously identified HDAC6 and HMGN2 as cofactors that facilitate prolactin induced, STAT5A mediated gene expression. Here, multi-condition STAT5A, HDAC6, and HMGN2 ChIP-seq with parallel condition RNA-seq are utilized to reveal the cis-regulatory landscape and cofactor dynamics underlying prolactin stimulated gene expression in breast cancer. We find that prolactin regulated genes are …

A Molecular Toolset For The In Vivo Detection Of A Sulfolobus Islandicus Leucyl Trna Synthetase Paralog, Nicholas Michael Bretz

Theses and Dissertations

An ancient and ubiquitous set of enzymes known as the aminoacyl-tRNA synthetases are required for the viability of all organisms. The aminoacyl-tRNA synthetases catalyze the attachment of amino acids onto tRNA molecules. The aminoacylated, or charged, tRNA is then transported and utilized at the ribosome for the synthesis of proteins. The genome of the hyperthermophilic microorganism Sulfolobus islandicus (S. islandicus) harbors a unique leucyl-tRNA synthetase paralog, LeuRS-I, of unknown function. While its duplicate, LeuRS-F, carries out all the classical functions of LeuRS-family enzymes, LeuRS-I fails to charge leucine onto tRNALeu, despite its ability to activate this amino acid and bind …

Effect Of Non-Muscle Myosin Ii Inhibition On Epigenetics During Oligodendrocyte Development, Amr Almaktari

Theses and Dissertations

Non-Muscle Myosin II (NMII) is a mechanosensitive motor protein implicated in oligodendrocyte (OL) development. The inhibition of NMII is known to promote OL development and maturation. This project found that NMII inhibition does not affect oligodendrocyte development by altering their epigenetic profile.

Expression Analyses Of Hippocampal And Cortical Proteins In A Rat Model For Alzheimer’S Disease, Rangon Islam

Theses and Dissertations

Currently, Alzheimer’s disease (AD) has no cure. Using a rat AD model, we identified aberrantly expressed proteins during pre-pathology as potential biomarkers. The expression of certain biomarkers was reversed by diazoxide, a repurposed hypertension drug. These results suggest that drug repurposing at an early stage of AD has therapeutic potential.

The Human Intermediate Prolactin Receptor: A Breast Cancer Proto-Oncogene, Jacqueline M. Grible

Theses and Dissertations

The hormone prolactin (PRL) and its receptor (hPRLr) are significantly involved in breast cancer pathogenesis. The intermediate hPRLr (hPRLrI) is an alternatively-spliced isoform, capable of stimulating cellular viability and proliferation. An analogous truncated mouse PRLr (mPRLr) was recently found to be oncogenic when co-expressed with wild-type mPRLr. hPRLrI co-expression with full-length hPRLr (hPRLrL) in MCF10AT cells resulted in robust in vivo and in vitro transformation, while hPRLrI knock-down in MCF7 cells significantly decreased in vitro malignant potential. hPRLrL+I heterodimers displayed greater stability than hPRLrL homodimers, and while being capable of activating Jak2, Ras, and MAPK, they were unable to induce …

The Origin And Evolution Of Flower Characters In Angiosperms With A Case Study On The Genetic Basis Of Zygomorphic Corolla Development In Bee And Hummingbird Pollinated Species Of Schizanthus (Solanaceae), Ghadeer Bukhari

Theses and Dissertations

This Ph.D. dissertation investigates two main projects separated into two chapters, one for each. The first chapter explores the evolution of flowering plants (angiosperms), a macro-scale study. The second project is on a micro-scale that focus on exploring the genes that regulate the similarities and the differences of flower morphology reflecting their different pollination syndromes in two species of Schizanthus (Solanaceae), i.e., S. pinnatus, a bee-pollinated flower, and S. grahamii, a hummingbird- pollinated flower.

In the first chapter, I used floral diagrams to study the origin and the evolution of floral traits in angiosperms, a new set of morphological data …

Anti-Tumor Functions Of Sphingosine Kinase 1 And Sphingosine Kinase 2 In Breast Cancer Development, Melissa A. Maczis

Theses and Dissertations

Bioactive sphingolipid metabolite sphingosine-1‐phosphate (S1P) circulating levels have been implicated in breast cancer (BC) progression. BCs usually respond to 17β-Estradiol (E2) through canonical receptor ERα66 for genomic effects, however, E2 also triggers rapid, non-genomic responses. E2 has been shown to activate sphingosine kinase 1 (SphK1), increasing S1P for S1P receptors signaling important for BC. The E2 receptor activating SphK1 has not been identified. We demonstrate triple negative BC cells, expressing only novel ERα splice variant ERα36, E2-induced SphK1 activation for S1P secretion. Tamoxifen, first-line BC endocrine therapy, an ERα66 antagonist but ERα36 agonist, activates SphK1 and increases S1P secretion in …

Augmenting Guadecitabine To Promote Anticancer Immunity In Murine Breast Cancer, Timothy M. Smith Jr.

Theses and Dissertations

In immune-competent individuals, tumor growth occurs due to a failure of the immune system to recognize and destroy malignant cells. Immune surveillance can be curtailed by the presence of immunosuppressive cells such as myeloid-derived suppressor cells (MDSCs) and T-regulatory cells (Tregs) which both serve to dampen antitumor immunity. These studies utilize a metronomic low-dose therapeutic approach to examine the effects of anticancer drugs against murine breast cancer and the effects on the immune cell compartments. The focus of these studies revolve around the drug guadecitabine (guad), a second-generation DNA methyl-transferase inhibitor (DNMTi). DNMTi’s have been shown to dysregulate the methylation …

The Role Of Ca2+/Calmodulin Dependent Protein Kinase Ii, Camk-Ii, In Kidney Morphogenesis, Sarah R. Ingram

Theses and Dissertations

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common heritable diseases in the world, characterized by the development of large fluid filled cyst. Treatments for this disease are limited due to a lack of understanding of disease pathogenesis. Ca²⁺/calmodulin dependent protein kinase II (CaMK-II) is necessary for kidney morphogenesis in zebrafish as well as being a downstream effector of pkd2, one of the genes most commonly mutated in ADPKD patients. The roles of CaMK-II during zebrafish kidney development include regulation of kidney cell migration as well as cloacal cilia stability. The influence of CaMK-II …

Disruption Of The Dream Complex Results In Cell Cycle Deregulation, Hayley C. Walston

Theses and Dissertations

The Dimerization Partner, Rb-like, E2F, And MuvB (DREAM) complex was identified in humans due to homology of the genes involved in the D. melanogaster dREAM complex. It assembles during cellular arrest, or G0, to function as a transcriptional repressor of cell cycle genes. It is known that phosphorylation of LIN52 at serine 28 is necessary for the critical DREAM forming interaction between LIN52 and the pocket protein p130. Our laboratory has previously shown that gene editing of LIN52 to replace serine 28 with alanine (S28A) prevents phosphorylation by the kinase DYRK1A and inhibits DREAM formation. Here we have confirmed this …

Higher Tensile Forces Across Cellular Junctions And An Intact Nuclear Linc Complex Is Required For Epithelial Function And Stability, Fnu Vani Narayanan

Theses and Dissertations

Recent advances in three-dimensional (3D) cell culture systems have provided key insights into the understanding of biochemical and physiological states of native tissue. A significant progress in the field of mechanobiology involves measuring cellular traction forces in a more native 3D environment. However, the effects of mechanical forces exerted across cellular junctions and the nuclear LINC complex, in an organized 3D system has not been investigated thus far. Epithelial cells spontaneously form acini (also known as cysts or spheroids) with a single, fluid-filled central lumen, when grown in 3D matrices. The size of the lumen is dependent on apical secretion …

Modulation Of Ferroportin In Oral Cancer, Ashley N. Hemingway

Theses and Dissertations

Iron plays a critical role in life sustaining functions for the cell. Dysregulation of these processes can be an issue with maintaining homeostatic conditions. Various cancer types have been observed to show malfunction in the maintenance of their iron homeostasis, in particular with the iron export protein—ferroportin. Ferroportin is the sole iron exporter known. Its structure and mechanism have not fully been elucidated yet, but its modulation has been associated with a poorer prognosis in cancers like breast, leukemia, prostrate, ovarian, colorectal, etc. Decreased iron exportation by ferroportin may lead to an increased labile iron pool allowing the cell to …

The Impact Of Aging And Mechanical Injury On Alveolar Epithelial And Macrophage Responses In Acute Lung Injury And Inflammation, Michael S. Valentine

Theses and Dissertations

Patients with severe lung pathologies, such as Acute Respiratory Distress Syndrome (ARDS), often require mechanical ventilation as a clinical intervention; however, this procedure frequently exacerbates the original pulmonary issue and produces an exaggerated inflammatory response that potentially leads to sepsis, multisystem organ failure, and mortality. This acute lung injury (ALI) condition has been termed Ventilator-Induced Lung Injury (VILI). Alveolar overdistension, cyclic atelectasis, and biotrauma are the primary injury mechanisms in VILI that lead to the loss of alveolar barrier integrity and pulmonary inflammation. Stress and strains during mechanical ventilation are believed to initiate alveolar epithelial mechanotransduction signaling mechanisms that contribute …

Sphingolipids In Cancer Health Disparities And As Prospective Targets For Cancer Therapy, April E. Boyd

Theses and Dissertations

Lung cancer is the deadliest cancer both in the United States and worldwide. Non-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancers. However, lung cancer disparities are not shared equally across racial groups, with large differences between African American and Caucasian populations. Advances in research have revealed roles of lipid mediators in cancer biology and disease progression, but sphingolipid alterations in tissues should be explored further. To address this, using mass spectrometry (MS), extensive sphingolipidomic characterization of NSCLC tumors and adjacent uninvolved tissues from African American and Caucasian patients were performed. This study revealed that NSCLC …

Ca2+/Calmodulin-Dependent Protein Kinase Type Ii (Camkii) Regulates Histone Methylation To Promote Zebrafish Hematopoietic Stem Cell Specification, Sanyam Patel

Theses and Dissertations

Ca²⁺/calmodulin dependent protein kinase II (CaMKII) is an important signaling molecule involved in many developmental processes. This project aims to understand the role of CaMKII in specification of hematopoietic stem cells (HSCs) in zebrafish. HSCs undergo hematopoiesis to specify all cells that constitute blood. The process of hematopoiesis along with the specification of hematopoietic stem cells is conserved in vertebrates. CaMKII is expressed in tissues important for HSC specification, including the somites, notochord, and dorsal aorta. The dorsal aorta is the site of HSC specification in zebrafish. Injection of camk2g1 translational blocking antisense oligonucleotides (MO) or Cas9 guide …

Why Did The Eisenhower Administration Decide To Deploy Jupiter Missiles In Turkey: A Case Study In Nuclearization Of Nato Strategy, Murat Iplikci

Theses and Dissertations

Looking out at the international political landscape of the late 1940s and the early 1950s, the Eisenhower administration was determined to challenge the evident appeal of Communism, particularly in Western Europe. NATO, which was a fragile organization due to the devastation of World War II (WWII), and its members were prone to any communist attack, either by military forces or through political parties. They had to be defended. The Eisenhower administration saw nuclear weapons as the only means to defend the alliance against the massive threat of the Soviet Union. Therefore, President Eisenhower committed nuclear weapons to NATO as a …

Regulation Of The Microtubule Cytoskeleton And Cell Wall Development In Arabidopsis Thaliana, Christy J. Fornero

Theses and Dissertations

Regulation of the cortical microtubule cytoskeleton is critical for organized plant cell division. Arabidopsis ton1 and ton2 mutants display random cell division plane placement and lack the plant-specific cortical microtubule array that encircles the nucleus prior to mitosis. In wild type plants, this preprophase band (PPB) of cortical microtubules precisely marks the future division plane. The specific roles of TON1 and TON2 in PPB formation are not yet known. It is suspected that TON1 Recruiting Motif (TRM) proteins may be involved in TON1 and TON2 recruitment to the PPB. Here we describe results for the targeted disruption of a group …

Understanding The Molecular And Cellular Functions Of Odd-Skipped Related 1 In Outflow Tract Development, Menglan Xiang

Theses and Dissertations

The cardiac outflow tract (OFT) is a transient conduit that connects the embryonic heart chambers to the vascular network. Transcription factor Osr1 promotes the proliferation and cell cycle progression of second heart field (SHF), an essential cell population that contribute to the developing OFT. In this study, we investigated the role of Osr1 in OFT development on cellular and molecular levels using a systems biology approach. We observed OFT rotation and elongation defects, as well as double-outlet right ventricle and overriding aorta as a result of SHF-specific deletion of Osr1. Using genetic inducible fate mapping, we showed that Osr1-expressing SHF …

Role Of Transient Receptor Potential Channels In Epithelial Morphogenesis In Chick Embryo, Trinity Q. Waddell

Theses and Dissertations

Transient Receptor Potential channels (TRP) are a superfamily of cationic specific ionchannels that are regulated by various stimuli such as temperature, pH, mechanical stress, ligandsand ion concentration. The role of TRP channels in disease states such as autosomal dominantpolycystic kidney disease, cancer metastasis, and developmental defects lend credence to thebelief that they play an important part in epithelial morphogenesis events. The development ofsomites, neural tube closure and migration of neural crest cells to form things such as the faceand heart is a good developmental model for the aforementioned cellular processes. We haveshown that TRP channels can be found in the …

Characterization Of Pth Type-2 Receptor ( Pth2rb ) And Its Endogenous Ligand Pth2 In Zebrafish Development, Nicholas Seitz

Theses and Dissertations

Members of the parathyroid hormone family of ligands, PTH (parathyroid hormone), PTH2, and PTHLH (parathyroid hormone-like hormone). These hormones interact with the class B GCPRs parathyroid hormone receptors PTH1R, PTH2R, and PTH3R to regulate a variety of biological processes. In mammals, PTH and PTHLH activate PTH1R and PTH3R to mediate serum calcium homeostasis, chondrogenesis, and bone maintenance. PTH2R activation by PTH2 has been studied primarily in regard to its neuroendocrine roles but is also found in the skin where it contributes to wound healing and keratinocyte differentiation. Still, little is known about the impacts of PTH2R signaling relative to PTH1R …

Deciphering The Consequences Of Yolk Testosterone Metabolism In Birds, Nicole A. Campbell

Theses and Dissertations

Maternal steroids transferred to eggs can elicit permanent effects on various aspects of offspring phenotype. Although, testosterone was thought to be a key mediator of maternal effects in birds, we now know that vertebrate embryos actively regulate their exposure to maternal testosterone through steroid metabolism, suggesting testosterone metabolites may elicit the observed phenotypic effects. To address the role steroid metabolism plays in mediating yolk testosterone effects, we used European starling (Sturnus vulgaris) eggs to characterize the timing of testosterone metabolism and determine whether etiocholanolone, a prominent testosterone metabolite in avian embryos, is capable of influencing early embryonic development. Tritiated testosterone …

Regorafenib Enhances Lethality Of Sildenafil And Curcumin In Colorectal Cancer Cells, Kervin Benjamin Owusu

Theses and Dissertations

In the United States, more than 130,000 people will be diagnosed with colorectal cancer (CRC) each year and an estimated 50,000 people will die from the disease. Standard of care (SOC) therapies for CRC combine multiple cytotoxic chemotherapeutic drugs. These combinations have varying degrees of effectiveness and can often result in significant patient morbidity. For second recurrence patients, the multi-kinase inhibitor, regorafenib, is an approved agent, but is often poorly tolerated at current doses. In the current study, we propose to develop therapeutic regime of combining agents with modest toxicity profiles: curcumin and sildenafil with regorafenib. Using clinically achievable enterohepatic …

Investigation Of The Interactions Between The Dream Complex And Hpv16, Kevin Ko

Theses and Dissertations

According to the American Cancer Society, it has been estimated that in 2019 alone, there will be approximately 53,000 new cases of oropharyngeal cancers. Oropharyngeal cancers are the largest subset of head and neck squamous cell carcinomas (HNSCCs), which are the sixth most common cancer across worldwide populations. They, along with other HNSCCs, fall under a category of cancers known as Human papillomavirus (HPV)-associated cancers, and it has been found that upwards of 70% of these cancers can be attributed to high-risk HPV infections.

Specifically, the high-risk HPV gene, E7, plays a key role in relieving cell cycle repression by …

Regulatory T Cells Promote Breast Cancer Progression Through Inhibiting Classical Activation Of Macrophages, Nicholas M. Clark

Theses and Dissertations

Transient ablation of regulatory T cells has been shown to be effective at hindering tumor growth and metastasis in murine breast cancer model. Based on our lab’s previous work, we have demonstrated that NK cells and CD8+ cytotoxic T cells were not required for the protective effect of Treg cell ablation. However, we also reported that CD4+ helper T cells and IFN-γ were required for the protective effect of Treg cell ablation. Furthermore, we observed that CD11B+ cells responded to Treg ablation therapy by up-regulating target genes of IFN-γ. Therefore, this study aimed to investigate the connection between the myeloid …