Cell and Developmental Biology Commons^™

Sphingosine Kinase 1 Regulates Fascin Expression To Promote Metastasis In Triple Negative Breast Cancer, Sunil Acharya

Dissertations and Theses (Open Access)

Distant metastasis is the primary cause of breast cancer–related mortality. To date, effective therapeutic drugs that target metastasis are still lacking. Triple negative breast cancer (TNBC) occurs in high frequency in young women and are more likely to recur and metastasize than are other breast cancer subtypes. Also, TNBC patients cannot benefit from currently available hormonal or targeted therapies, as they lack estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2. Thus, understanding the signaling pathways that promote TNBC metastasis and developing novel therapeutic approaches to target them are critical, in order to prolong the survival and improve …

Deciphering The Roles Of Δnp63 In Regulating Epithelial To Mesenchymal Transition, Cancer Progression And Metastasis, Ngoc Bui

Dissertations and Theses (Open Access)

p63 is a member of the p53 family, a well-known tumor suppressor which is considered the guardian of the genome. The TP63 gene encodes multiple isoforms that can be categorized into two main isoforms, TAp63 and ΔNp63, which are expressed in different cellular compartments and have distinct functions in many biological processes. While the Flores laboratory identified TAp63 as a tumor and metastasis suppressor, the precise roles of ΔNp63 isoforms in tumorigenesis and metastasis remain elusive. ΔNp63 is the predominant p63 isoform expressed in the epidermis and plays essential roles in regulating epidermal development and homeostasis. Utilizing a ΔNp63-conditional …

Trim24 As An Oncogene In The Mammary Gland, Aundrietta Duncan

Dissertations and Theses (Open Access)

Despite the many advances made in breast cancer research and treatments, breast cancer remains one of the deadliest diseases plaguing women worldwide. While many findings on genetic mutations and their role in predisposing people to breast cancer have been uncovered, we are just beginning to understand the extent to which epigenetic regulators promote tumorigenic phenotypes, metastasis, and chemotherapeutic resistance. Moreover, new experimental tools offer the ability to address questions we were previously unable to assess. My project takes advantage of a new mouse model to understand the role of a proto-oncogenic, transcriptional co-regulator, TRIM24, in mammary gland development and disease. …

Identification And Utility Of Dna In Exosomes, Paul Kurywchak

Dissertations and Theses (Open Access)

Cancer-associated mortality has been declining for two decades but remains a significant public health problem, especially when patients initially present with advanced disease. Early detection methods have improved survival rates but remain unavailable for a majority of cancers due to a lack of sensitive biomarkers or numerous limitations associated with current diagnosis strategies. Approaches to develop “liquid biopsies” by detecting tumor cells or DNA in the blood have led to several breakthroughs and create the potential for non-invasive, routine assessment of diseases status. However, these biomarkers are rare and currently difficult to isolate, especially in the early stages of disease. …

The Regulation Of Dna Methylation In Mammalian Development And Cancer, Nicolas Veland

Dissertations and Theses (Open Access)

DNA methylation is an essential epigenetic modification in mammals, as it plays important regulatory roles in multiple biological processes, such as gene transcription, maintenance of chromosomal structure and genomic stability, genomic imprinting, retrotransposon silencing, and X-chromosome inactivation. Dysregulation of DNA methylation is associated with various human diseases. For example, cancer cells usually show global hypomethylation and regional hypermenthylation, which have been implicated in genomic instability and tumor suppressor silencing, respectively. Although great progress has been made in elucidating the biological functions of DNA methylation over the last several decades, how DNA methylation patterns and levels are regulated and dysregulated is …

Mitochondrial Mrna Translation Is Required For Maintenance Of Oxidative Capacity, David Lee

Graduate Theses and Dissertations

Oxidative metabolism is required to produce adequate energy to sustain human life. A primary example of deteriorating oxidative capacity is seen in the cardiac musculature during chronic heart failure. This suggests that by improving oxidative potential, chronic heart disease could be mitigated and one approach to accomplish this may be through targeting the mt-mRNA translation system. Purpose: This investigation’s purpose was to characterize disruptions in mt-mRNA translation machinery in multiple forms of cardiomyopathy and to determine if mitochondrial mRNA translation initiation factor (mtIF2) is necessary to maintain oxidative capacity in cardiomyocytes. Methods Using a combination of animal and cell culture …

Combining Translational And Functional Genomic Approaches To Augment Management Strategies Of Plant Parasitic Nematodes, Sandeep Sharma Khatiwada

Graduate Theses and Dissertations

Plant-parasitic nematodes pose a major threat to crop yield worldwide. Discontinued use of harmful chemicals has prompted the search for alternative management strategies that are effective yet environmentally friendly. Harpin proteins, which are derived from bacteria, and nematophagous fungi, natural predators of nematodes, are ideal for biological control of plant-parasitic nematodes. However, research on the efficacy of harpin proteins on nematodes, and biology of nematophagous fungi is minimal. Previously, a taxonomically uncharacterized nematophagous fungus designated ARF18 effectively suppressed nematode populations in soil. The overarching goal of this dissertation is to utilize applied and functional genomic approaches to augment management of …

Multiscale Investigation Of The Behavior Of Heart Valve Interstitial Cells In Response To Pathological Shape And Mechanical Stimulation, Ngoc Thien Lam

Graduate Theses and Dissertations

Our works aim to provide an insight into how aortic valve interstitial cells (VICs) respond to pathological shape and mechanical stimulation as well as the potential signaling pathway that mediates these responses, using a multiscale approach. A single cell model was developed to investigate the effect of altered shape on valve cell function as valve cells were reported to significantly deform during the cardiac cycle. Single VICs were controlled to take on features with different width-to-length aspect ratios that corresponded to the steady-state shapes adopted by VICs when stretched to 0%, 10% and 20%, respectively. It appeared that single VIC …

Microbiome Of Commercial Broilers Through Evisceration And Immersion Chilling, John A. Handley

Graduate Theses and Dissertations

The United States poultry industry generated 38.6 billion pounds (17,500 metric ton) of meat in 2014 which averaged to 121 pounds (55 kg) per individual of the U.S that same year. Of that meat generated by the poultry industry, an estimated 1 million cases of Salmonellosis will occur. Out of the 1 million cases approximately 40, 000 to 50,000 will be confirmed cases by the CDC. Recently, the USDA has requested changes in the inspection process and are currently allowing processors more freedom to utilize innovation to drive the increase in safer and more desirable foods. The new standards set …

In Vivo Structure-Function Analysis Of Drosophila Robo1, An Axon Guidance Receptor Critical For Midline Repulsive Signaling In The Embryonic Central Nervous System, Haley Brown

Graduate Theses and Dissertations

The repellant ligand Slit and its Roundabout (Robo) family receptors regulate many aspects of axon guidance in bilaterians, including midline crossing of axons during development of the embryonic CNS. Slit proteins are produced by midline cells and signal through Robo receptors expressed on the surface of axonal growth cones to repel axons from the midline. Disruption of Slit-Robo signaling causes ectopic midline crossing phenotypes in the CNS of a broad range of animals, including insects and vertebrates.

Drosophila Robo1 has a conserved ectodomain structure of five immunoglobulin-like (Ig) domains plus three fibronectin (FN) repeats. By utilizing a genomic rescue construct …

Roles Of Phospholipases And Ribosomal S6 Kinase In Lipid Remodeling And Growth In Arabidopsis Response To Phosphate Deprivation, Yuan Su

Dissertations

Phosphate (Pi) is one of three macronutrients for plants, which is vital for plant growth and development. Understanding the mechanism by which plants respond and adapt to Pi deficiency not only unveils functions of genes and pathways involved, but also provides potential tools to manipulate crops to better stand Pi stress in low Pi-containing lands. One of the significant metabolic changes in plants under Pi starvation is the membrane lipid remodeling that converts Pi-containing lipids such as phospholipids to Pi-free lipids, such as glycolipids. To elucidate the metabolism and regulation of lipid remodeling, this dissertation characterizes the role of two …

Reconstitution Of Gabaergic Postsynapses In Host Cells, Karthik Kanamalla

Honors Scholar Theses

Type A GABA receptors (GABAARs) can be found embedded in postsynaptic membranes or in a variety of extrasynaptic locations. Receptors with synaptic function are recruited to the postsynapse by submembranous scaffolds composed of gephyrin and collybistin (CB). This study was aimed at assessing whether the ability to interact with the scaffold differentiates synaptic from non-synaptic receptors. Using HEK293 cells as an expression system, and indirect immunofluorescence (IF), co-localization of extrasynaptic receptors α1β3δ and α4β3δ with the CB-gephyrin scaffold was assessed and compared with that of the synaptic receptor α1β3γ2. Results indicated that both extrasynaptic receptors were able to colocalize with …

Investigating The Molecular Function Of Akirin During Skeletal Myogenesis In Drosophila Melanogaster, Kristina Rowland

Master of Science in Integrative Biology Theses

The specification and differentiation of muscle precursor cells, or myoblasts, by the action of the mesodermal and muscle transcription regulator Twist is a key event in the formation of the Drosophila larval musculature. Akirin, a highly conserved nuclear protein, appears to play a critical role in the regulation of Twist-dependent gene expression during mesodermal specification and muscle development. Specifically, Akirin serves as a cofactor to promote interactions between regulatory transcription factors and multisubunit Brahma SWI/SNF-class chromatin remodeling complex to impact gene expression across varying targets. Using a genetic interaction screen in Drosophila, we have begun to identify other Akirin …

Mtbp Inhibits The Erk1/2-Elk-1 Signaling In Hepatocellular Carcinoma, Atul Ranjan, Swathi V. Iyer, Christopher Ward, Tim Link, Francisco J. Diaz, Animesh Dhar, Ossama W. Tawfik, Steven A. Weinman, Yoshiaki Azuma, Tadahide Izumi, Tomoo Iwakuma

Toxicology and Cancer Biology Faculty Publications

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and the prognosis of HCC patients, especially those with metastasis, remains extremely poor. This is partly due to unclear molecular mechanisms underlying HCC metastasis. Our previous study indicates that MDM2 Binding Protein (MTBP) suppresses migration and metastasis of HCC cells. However, signaling pathways regulated by MTBP remain unknown. To identify metastasis-associated signaling pathways governed by MTBP, we have performed unbiased luciferase reporter-based signal array analyses and found that MTBP suppresses the activity of the ETS-domain transcription factor Elk-1, a downstream target of Erk1/2 MAP kinases. MTBP also inhibits phosphorylation …

Human Cancer And Platelet Interaction, A Potential Therapeutic Target, Shike Wang, Zhenyu Li, Ren Xu

Markey Cancer Center Faculty Publications

Cancer patients experience a four-fold increase in thrombosis risk, indicating that cancer development and progression are associated with platelet activation. Xenograft experiments and transgenic mouse models further demonstrate that platelet activation and platelet-cancer cell interaction are crucial for cancer metastasis. Direct or indirect interaction of platelets induces cancer cell plasticity and enhances survival and extravasation of circulating cancer cells during dissemination. In vivo and in vitro experiments also demonstrate that cancer cells induce platelet aggregation, suggesting that platelet-cancer interaction is bidirectional. Therefore, understanding how platelets crosstalk with cancer cells may identify potential strategies to inhibit cancer metastasis and to reduce …

In Vivo Structures Of The Helicobacter Pylori Cag Type Iv Secretion System, Yi-Wei Chang, Carrie L. Shaffer, Lee A. Rettberg, Debnath Ghosal, Grant J. Jensen

Veterinary Science Faculty Publications

The type IV secretion system (T4SS) is a versatile nanomachine that translocates diverse effector molecules between microbes and into eukaryotic cells. Here, using electron cryotomography, we reveal the molecular architecture of the Helicobacter pylori cag T4SS. Although most components are unique to H. pylori, the cag T4SS exhibits remarkable architectural similarity to other T4SSs. Our images revealed that, when H. pylori encounters host cells, the bacterium elaborates membranous tubes perforated by lateral ports. Sub-tomogram averaging of the cag T4SS machinery revealed periplasmic densities associated with the outer membrane, a central stalk, and peripheral wing-like densities. Additionally, we resolved pilus-like …

Restoration Of Phage Growth On A Non-Permissive Host By Bypassing Transcription Termination Signals, Millicent Ronkainen

Mahurin Honors College Capstone Experience/Thesis Projects

RNA polymerase is the central enzyme in all gene expression. The rpoCY75N mutation in the zinc-binding domain of the β’ subunit of E. coli RNA polymerase blocks a unique RNA-based mechanism of transcription antitermination utilized by bacteriophage HK022 and its relatives. Here, we describe the characterization of mutant phage, orc0368, which overcomes the rpoCY75N mutation. The orc0368 genome varies from the wild type phage genome by 4 single base pair mutations. Three of these mutations were not characterized because they occur in intergenic regions but the fourth was chosen for study because of its location between a series …

Differential Expression Of Mtor Related Molecules In The Placenta Of Patients With Gestational Diabetes Mellitus, Intrauterine Growth Restriction, Or Preeclampsia, Katherine Price, Brent Kimbler, Nekel Knowlton, Kelsey Hirschi, Paul Reynolds, Juan Arroyo

Student Works

The mechanistic target of rapamycin (mTOR) pathway is involved in placental growth and function during pregnancy. The mTOR pathway responds to nutrient availability and growth factors regulating protein transcription and cell growth. mTOR disruptions are associated with the development of obstetric complications which may result in adverse health outcomes for the mother and/or fetus. The purpose of this study is to identify the differing placental expression of various mTOR-associated proteins during normal gestation (Control), gestational diabetes mellitus (GDM), intrauterine growth restriction (IUGR) and preeclampsia (PE). Immunohistochemistry was used to stain human placenta for activated proteins (phospho; p)AKT, (p)ERK, (p)mTOR, (p)p70 …

Twist Promotes Tumor Metastasis In Basal-Like Breast Cancer By Transcriptionally Upregulating Ror1, Jingying Cao, Xin Wang, Tao Dai, Yuanzhong Wu, Meifang Zhang, Renxian Cao, Ruhua Zhang, Gang Wang, Rou Jiang, Binhua P. Zhou, Jian Shi, Tiebang Kang

Markey Cancer Center Faculty Publications

Rationale: Twist is a key transcription factor for induction of epithelial-mesenchymal transition (EMT), which promotes cell migration, invasion, and cancer metastasis, confers cancer cells with stem cell-like characteristics, and provides therapeutic resistance. However, the functional roles and targeted genes of Twist in EMT and cancer progression remain elusive.

Methods: The potential targeted genes of Twist were identified from the global transcriptomes of T47D/Twist cells by microarray analysis. EMT phenotype was detected by western blotting and immunofluorescence of marker proteins. The dual-luciferase reporter and chromatin immunoprecipitation assays were employed to observe the direct transcriptional induction of ROR1 by Twist. A lung …

Investigation Of Alcohol-Induced Changes In Hepatic Histone Modifications Using Mass Spectrometry Based Proteomics, Crystina Leah Kriss

USF Tampa Graduate Theses and Dissertations

Alcohol liver disease (ALD) is a major health concern throughout the world. Currently, in the United States, 17 million people suffer from alcoholism, of which 1.4 million people are receiving treatment [1, 2]. The link between ethanol metabolism, reactive oxygen species (ROS) and liver injury in ALD has been well characterized over the last couple decades [3-10]. Ethanol metabolism relies on the availability of the cofactor NAD+ for the oxidation of ethanol into acetate, consequently causing alterations in redox potential. Redox dysfunction within the mitochondria can affect multiple pathways important in maintaining cellular homeostasis. Chapter 1 provides an introduction to …

The Role Of Phosphohistidine Phosphatase 1 In Ethanol-Induced Liver Injury, Daniel Richard Martin

USF Tampa Graduate Theses and Dissertations

Chronic liver diseases, which includes alcoholic liver disease (ALD), are consistently among the top 15 leading causes of death in the United States. ALD is characterized by progression from a normal liver to fatty liver disease (hepatic steatosis), which can lead to cirrhosis, alcoholic hepatitis, and liver failure. We have identified a novel role of phosphohistidine signaling, mediated through phosphohistidine phosphatase 1 (PHPT1), in the onset of hepatic steatosis. We have identified PHPT1 as a target of selective oxidation following acute ethanol exposure as well as being downregulated following chronic ethanol exposure. We mapped the oxidative modification site and developed …

Sirna Knock-Down Of Vav1 In Breast Cancer Cells: Effects On Pi3kinase And Akt, Tajai Sion-Milligan

Student Scholar Showcase

One in eight women in the United States will be diagnosed with breast cancer. Approximately 25-30% of these breast tumors will overexpress Human Epidermal Growth Factor Receptor 2 (HER2), associated with a worse prognosis and decreased survival rate. Stimulation of HER2 results in activation and production of many signaling molecules, ultimately resulting in increased cell division. Two of the downstream molecules activated are PI₃Kinase and, further downstream, the molecule Akt. Typically, overproduction and/or overactivation of PI₃Kinase can lead to oncogenesis. A molecule that may have a significant role in PI₃Kinase formation is VAV1. VAV1 …

Extracellular Atp Effects On Intracellular Actin Fibrils' Location And Characteristics [Poster], Dianna Huisman, David Mcclenahan, Ali Tabei, Joseph Tibbs

Research in the Capitol

Epithelial cells lining secretory units and ducts of bovine mammary glands perform an important role in regulating movement of various macromolecules and whole cells during normal lactation and mastitis. During mastitis, host and bacterial produced substances can affect the “barrier” function of epithelial monolayers. One potential component is adenosine triphosphate (ATP). ATP likely interacts with P2X7, a purinergic receptor, in mediating some effects associated with mastitis. Bovine mammary gland epithelial cell line, Mac-T cells, were examined for cytoskeletal changes as result of P2X7 interactions. Actin cytoskeletons were stained with phalloidin and effects were examined by fluorescent microscopy. Observable increase in …

Vesicles Mimicking Normal And Cancer Cell Membranes Exhibit Differential Responses To The Cell-Penetrating Peptide Pep-1, Bashiyar Almarwani, Esther Nzuzi Phambu, Christopher Alexander, Ha Aimee T. Nguyen, Nsoki Phambu, Anderson Sunda-Meya

Chemistry Faculty Research

The cell-penetrating peptide (CPP) Pep-1 presents a great potential in drug delivery due to its intrinsic property to cross plasma membrane. However, its mechanism of entry into the cell remains unresolved. In this study, we compare the selectivity of Pep-1 towards vesicles mimicking normal and cancer cell membranes. The interaction was performed in a wide range of peptide-to-lipid molar ratios using infrared (IR), fluorescence, scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. At low peptide concentration, fluorescence experiments show that lipid-phosphatidylserine (PS) seems to enable Pep-1 translocation into cancer cell membrane as evidenced by the …

Reduced Intraepithelial Corneal Nerve Density And Sensitivity Accompany Desiccating Stress And Aging In C57bl/6 Mice, Mary Ann Stepp, Sonali Pal-Ghosh, Gauri Tadvalkar, Alexa Williams, S Pflugfelder, C De Paiva

Anatomy and Regenerative Biology Faculty Publications

Dry Eye disease causes discomfort and pain in millions of patients. Using a mouse acute desiccating stress (DS) model we show that DS induces a reduction in intraepithelial corneal nerve (ICN) density, corneal sensitivity, and apical extension of the intraepithelial nerve terminals (INTs) that branch from the subbasal nerves (SBNs). Topical application of 0.02% Mitomycin C (MMC) or vehicle alone has no impact on the overall loss of axon density due to acute DS. Chronic dry eye, which develops progressively as C57BL/6 mice age, is accompanied by significant loss of the ICNs and corneal sensitivity between 2 and 24 months …

Investigating The Apoptotic Effects Of Platinum(Ii) Amine Complexes With Only One Leaving Ligand On Zebrafish Auditory End Organs, Joshua Smith

Masters Theses & Specialist Projects

The FDA-approved platinum compound, cisplatin, is commonly used as a chemotherapy drug to treat many forms of cancer. However, this compound also has several associated side-effects, including ototoxicity. This has made the development of novel platinum compounds that reduce cancer cell viability, while causing fewer and milder side-effects, an area of significant research interest. In the present study, we examined the apoptotic effects that four monofunctional platinum compounds, pyriplatin, phenanthriplatin, Pt(diethylenetriamine)Cl, and Pt(N,Ndiethyldiethylenetriamine) Cl, had on zebrafish inner ear auditory epithelial cells. We then compared the apoptotic effects of these compounds to those of cisplatin, which is a bifunctional platinum …

Characterizing The Role Of Cp1 In Drosophila Melanogaster: Its Effects On Basement Membrane Degradation And Signaling, Dane Alan Flinchum

Masters Theses & Specialist Projects

CP1 is a well-conserved cathepsin L-like protease essential for proper growth and development in Drosophila melanogaster. Previous research has demonstrated that CP1 has the ability to break down the extracellular matrix. Using the UAS-GAL4 system, immunohistochemistry, and antibody-staining, this research attempts to characterize the role of CP1 and its effects on basement membrane degradation and signaling. These effects include actions at the cellular level and on a known signaling pathway. The genes involved in this pathway are known to be required for proper development of the wing disc into the adult wing. We have demonstrated the collagenase activity of CP1 …

Do Paraben Derivatives Alter T Cell Immunity?, Hailey Kintz

Spring Presentation of Undergraduate Research

T cells immunity is linked to a complex system of cytokines that determine differentiation of naïve T cells into Th1, Th2, Th17, and Treg cells. Estrogen production or periods of elevated production have been correlated with an anti-inflammatory state in which Th2 and Treg cells are up-regulated. Such responses in the immune system are capable of supporting pre-cancerous activity. We are investigating the tie between the xenoestrogen compounds found in cosmetics, parabens, and their ability to regulate T cell immunity. Testing parabens and paraben derivatives with weaker estrogen receptor association will allow for a better understanding of the interplay between …

Quantitative 3-D Head Ultrasound Measurements Of Ventricle Volume To Determine Thresholds For Preterm Neonates Requiring Interventional Therapies Following Posthemorrhagic Ventricle Dilatation, Jessica Kishimoto, Aaron Fenster, David S.C. Lee, Sandrine De Ribaupierre

Anatomy and Cell Biology Publications

Dilatation of the cerebral ventricles is a common condition in preterm neonates with intraventricular hemorrhage. This posthemorrhagic ventricle dilatation (PHVD) can lead to lifelong neurological impairment through ischemic injury due to increased intracranial pressure, and without treatment can lead to death. Two-dimensional ultrasound (US) through the fontanelles of the patients is serially acquired to monitor the progression of PHVD. These images are used in conjunction with clinical experience and physical exams to determine when interventional therapies such as needle aspiration of the built up cerebrospinal fluid (ventricle tap, VT) might be indicated for a patient; however, quantitative measurements of the …

Hiv Suppresses Cervical Neutrophil Infiltration In Women With Normal Or Abnormal Pap Smears, Mika Caplan, Peter C. Angeletti, Duan Loy, Kandali Samwel, Daniela Gonzalez, Crispin Chisanga, Julius Mwaiselage, Asafu Munema, Brenda Bashekera, Kessy Goodwin, John Dustin Loy, John T. West, Charles Wood

UCARE: Research Products

Human immunodeficiency virus (HIV) infection of CD4+ T cells results in a weakened immune system due to decreased white blood cells, particularly multi-lobed neutrophils (neutropenia) and other granulocytes.¹ The purpose of this study was to determine whether a correlation exists between HPV/HIV status and presence of neutrophils. To test this, we used a computer software program (QuPath) to analyze neutrophil infiltration seen in pap smears of both HIV+ and HIV- patients from samples collected in Tanzania from three different sites: Bagamoyo, Chalinze, and Dar es Salaam. The software was used to quantify neutrophils per image based on the size …