Cell and Developmental Biology Commons^™

Self-Regulation Of Functional Pathways By Motifs Inside The Disordered Tails Of Beta-Catenin, Bi Zhao, Bin Xue

Molecular Biosciences Faculty Publications

Background: Beta-catenin has two major functions: coordinating cell-cell adhesion by interacting with cadherin in cadherin junction formation pathway; and regulating gene expression through Wnt signaling pathway. Accomplishing these two functions requires synergistic action of various sequential regions of the same beta-Catenin molecule, including the N-terminal tail, the middle armadillo domain, and the C-terminal tail. Although the middle armadillo domain is the major functional unit of beta-Catenin, the involvement of tails in the regulation of interacti on between beta-Catenin and its partners has been well observed. Nonetheless, the regulatory processes of both tails are still elusive. In addition, it is interesting …

Mir146a-Mediated Targeting Of Fancm During Inflammation Compromises Genome Integrity, Devakumar Sundaravinayagam, Hye R. Kim, Ting T. Wu, Hyun H. Kim, Hyun-Seo Lee, Semo Jun, Jeong-Heon Cha, Younghoon Kee, Ho J. You, Jung-Hee Lee

Molecular Biosciences Faculty Publications

Inflammation is a potent inducer of tumorigenesis. Increased DNA damage or loss of genome integrity is thought to be one of the mechanisms linking inflammation and cancer development. It has been suggested that NF-κB-induced microRNA-146 (miR146a) may be a mediator of the inflammatory response. Based on our initial observation that miR146a overexpression strongly increases DNA damage, we investigated its potential role as a modulator of DNA repair. Here, we demonstrate that FANCM, a component in the Fanconi Anemia pathway, is a novel target of miR146a. miR146a suppressed FANCM expression by directly binding to the 3’ untranslated region of the gene. …

Hepatic Nutrient And Hormonal Regulation Of The Pancreatic-Derived Factor (Pander) Promoter, Whitney Ratliff

USF Tampa Graduate Theses and Dissertations

PANcreatic-DERived factor (PANDER, FAM3B) has been shown to regulate glycemic levels via interactions with both pancreatic islets and the liver. Although PANDER is predominantly expressed from the endocrine pancreas, recent work has provided sufficient evidence that the liver may also be an additional tissue source of PANDER production. At physiological levels, PANDER is capable of disrupting insulin signaling and promoting increased hepatic glucose production. As shown in some animal models, strong expression of PANDER, induced by viral delivery within the liver, induces hepatic steatosis. However, no studies to date have explicitly characterized the transcriptional regulation of PANDER from the liver. …

Characterization And Diurnal Measurement Of Oral Inflammation In Association With Glycemic Control, Periodontal Status, & Glucose Stimulation, Melanie N. Kuehl

USF Tampa Graduate Theses and Dissertations

Diabetes has afflicted 8.3%, approximately 25.8 million, of the United States population and is the seventh leading cause of death [1]. Type I diabetes (T1D) accounts for 5 to 10% of all diagnosed cases of diabetes in the United States [2]. If present trends continue, the rate of T1D incidence among children under the age of 14 will increase by 3% globally [3]. T1D is an autoimmune disorder in which the β-cells of the pancreatic islets are destroyed, leading to high blood sugar. Hyperglycemia and loss of immunological tolerance to self-antigens are common associations of T1D [4]. Periodontal disease impacts …

Function Of Long Noncoding Rnas In Breast Cancer, Edward J. Richards

USF Tampa Graduate Theses and Dissertations

Breast cancer is a disease that will be diagnosed in about 1 in 10 women throughout their lifetime. The majority of breast cancers are originated from the epithelial cells of the mammary ducts, and this occurrence can be due to several factors including hereditary and acquired mutation. There are several major breast cancer subtypes, including estrogen receptor-α (ERα)-positive, HER2-enriched and triple-negative (TNBC). Patients diagnosed with ER+ tumors are generally treated with estrogen blockers (e.g., tamoxifen, letrozole and fulvestrant). Patients with HER2+ tumors are commonly administered with drugs that block HER2 signaling (e.g., trastuzumab) or inhibit HER2’s tyrosine kinase activity (e.g., …

Aspirin Triggered Resolution Phase Interaction Product D1: A Novel Treatment For Hyperoxic Acute Lung Injury, Ruan Rollin Cox, Jr.

USF Tampa Graduate Theses and Dissertations

Acute Lung injury (ALI) and the more severe acute respiratory distress syndrome (ARDS) are respiratory maladies that present immense clinical challenges. ALI affects 200,000 individuals annually and features a 40% mortality rate. ALI can be initiated by both pathogenic and sterile insults originating locally in the lungs or systemically. While immense research has been poured into this disease in an effort to find a therapeutic strategy, the heterogeneously diffuse nature of the disease has not yielded a cure for the disease. Death from this disease is strongly attributed to reduced gas exchange from a severely compromised alveolar-capillary barrier. The only …

Promoting Genome Stability Via Multiple Dna Repair Pathways, Scott Cukras

USF Tampa Graduate Theses and Dissertations

Maintaining genome integrity is indispensible for cells to prevent and limit accruement of deleterious mutations and to promote viable cell growth and proliferation. Cells possess a myriad of mechanisms to detect, prevent and repair incurred cellular damage. Here we discuss various proteins and their accompanying cellular pathways that promote genome stability. We first investigate the NEDD8 protein and its role in promoting homologous recombination repair via multiple Cullin E3 ubiquitin ligases. We provide specific mechanisms through which, UBE2M, an E2 conjugating enzyme, neddylates various Cullin ligases to render them catalytically active to degrade their substrates by the proteasome. We show …

Utilizing Systems Level Approaches To Identify Key Mechanisms Of Drug Resistance In Braf Mutated Melanoma, Kim H.T. Paraiso

USF Tampa Graduate Theses and Dissertations

In the last four years, seven new drugs have been FDA approved for the treatment of late stage melanoma, for the field of melanoma, this marks an incredibly exciting. Three of these new therapies, vemurafenib, dabrafenib and trametinib are small molecule kinase inhibitors that target the MAPK pathway and as such have been approved for the treatment of BRAFV600 mutant melanomas. Yet despite recent advances, mechanisms of intrinsic and acquired BRAF inhibitor resistance continue to undermine uniform and long-lasting therapeutic responses. Several studies have shown that the reactivation of MAPK signaling is a critical event leading to BRAF inhibitor resistance. …

Inhibition Of Shp2 Suppresses Mutant Egfr-Induced Lung Tumors In Transgenic Mouse Model Of Lung Adenocarcinoma, Valentina E. Schneeberger, Yuan Ren, Noreen Luetteke, Qingling Huang, Liwei Chen, Harshani R. Lawrence, Nicholas J. Lawrence, Eric B. Haura, John M. Koomen, Domenico Coppola, Jie Wu

Molecular Biosciences Faculty Publications

Epidermal growth factor receptor (EGFR) mutants drive lung tumorigenesis and are targeted for therapy. However, resistance to EGFR inhibitors has been observed, in which the mutant EGFR remains active. Thus, it is important to uncover mediators of EGFR mutant-driven lung tumors to develop new treatment strategies. The protein tyrosine phosphatase (PTP) Shp2 mediates EGF signaling. Nevertheless, it is unclear if Shp2 is activated by oncogenic EGFR mutants in lung carcinoma or if inhibiting the Shp2 PTP activity can suppress EGFR mutant-induced lung adenocarcinoma. Here, we generated transgenic mice containing a doxycycline (Dox)-inducible PTP-defective Shp2 mutant (tetO-Shp2CSDA). Using the rat Clara …

The Νsaα Specific Lipoprotein Like Cluster (Lpl) Of S. Aureus Usa300 Contributes To Immune Stimulation And Invasion In Human Cells, Minh Thu Nguyen, Beatrice Kraft, Wenqi Yu, Dogan Doruk Demicrioglu, Tobias Hertlein, Marc Burian, Mathias Schmaler, Klaus Boller, Isabelle Bekeredjian-Ding, Knut Ohlsen, Birgit Schittek, Friedrich Götz

Molecular Biosciences Faculty Publications

All Staphylococcus aureus genomes contain a genomic island, which is termed νSaα and characterized by two clusters of tandem repeat sequences, i.e. the exotoxin (set) and 'lipoprotein-like' genes (lpl). Based on their structural similarities the νSaα islands have been classified as type I to IV. The genomes of highly pathogenic and particularly epidemic S. aureus strains (USA300, N315, Mu50, NCTC8325, Newman, COL, JH1 or JH9) belonging to the clonal complexes CC5 and CC8 bear a type I νSaα island. Since the contribution of the lpl gene cluster encoded in the νSaα island to virulence is unclear to date, we deleted …

Regulation And Targeting Of The Fancd2 Activation In Dna Repair, Valentina Celeste Caceres

USF Tampa Graduate Theses and Dissertations

Fanconi anemia (FA) is a genome instability syndrome that is clinically manifested by bone marrow failure, congenital defects, and elevated cancer susceptibility. The FA pathway is known to regulate the repair of DNA interstrand crosslinks in part through DNA homologous recombination (HR) repair. Up to today 16 FA proteins have been discovered that may participate in the common pathway. Cells that have mutations in the FA genes are hypersensitive to DNA damaging agents and display chromosome instability. A key regulatory event in the FA pathway is monoubiquitination of FANCD2-FANCI heterodimer that is mediated by a multi-component E3 ubiquitin ligase complex …

High-Throughput Screening Of Age-Related Changes In Caenorhabditis Elegans, Neil Copes

USF Tampa Graduate Theses and Dissertations

This project was developed to identify novel methods for high-throughput culturing and screening of C. elegans to investigate age-related metabolic changes and to survey the proteomic and metabolomic factors associated with age-related changes. To accomplish these goals we developed a novel way to grow C. elegans in liquid culture in 96-well microplates for several weeks without suffering significant fluid loss due to evaporation and without needing to shake or unseal the plates for aeration. We also developed methods for assaying the total volume of live C. elegans in microplate cultures using a fluorescence microplate reader and for performing RNAi experiments …

Strategies For Preventing Age And Neurodegenerative Disease-Associated Mitochondrial Dysfunction, Vedad Delic

USF Tampa Graduate Theses and Dissertations

Mitochondrial dysfunction plays a pivotal role in the development of aging phenotypes and aging-associated neurodegenerative disorders, such as Alzheimer’s disease (AD), Parkinson’s disease (PD) and Amyotrophic lateral sclerosis (ALS). Strategies that restore mitochondrial dysfunction may rescue the deficits of central metabolism in these disorders and improve cell survival. For example, we found that modulating the mTOR signaling pathway in a tissue culture model of aging-induced mitochondrial DNA mutation enhanced mitochondrial function as evidenced by increased oxygen consumption. Our previous melatonin studies also led us to hypothesize that caloric restriction and the hormone melatonin would reverse brain mitochondrial dysfunction in animal …

Genomic Aberrations At The 3q And 14q Loci: Investigation Of Key Players In Ovarian And Renal Cancer Biology, Punashi Dutta

USF Tampa Graduate Theses and Dissertations

Genomic aberrations are primary contributors to the pathophysiology of cancer [11]. Dysregulated expression of genes located within these aberrations are important predictors of chemoresistance, disease prognosis, and patient outcome [12]. This dissertation is focused on understanding the regulation and/or functions of specific genes located at dysregulated genomic regions such as 3q26 and 14q32 in the biology of ovarian and renal cancer, respectively.

Serous epithelial ovarian cancer (EOC) manifest amplification at the 3q26.2 locus [2], an observation consistent with the cancer genome atlas (TCGA) [13]. The most amplified gene in this region is EVI1 which has been extensively studied in hematological …

The Effects Of Supplemented Metabolites On Lifespan And Stress Response Pathways In Caenorhabditis Elegans, Clare B. Edwards

USF Tampa Graduate Theses and Dissertations

Understanding how metabolites contribute to anaplerosis, antioxidant effects, and hormetic pathways during aging is fundamental to creating supplements and dietary habits that may decrease age-associated disease and decline, thus improving the quality of life in old age. In order to uncover metabolic pathways that delay aging, the effects of large sets of metabolites associated with mitochondrial function on lifespan were investigated.

Malate, the tricarboxylic acid (TCA) cycle metabolite, increased lifespan and thermotolerance in C. elegans. Addition of fumarate and succinate also extended lifespan and all three metabolites activated nuclear translocation of the cytoprotective DAF-16/FOXO transcription factor and protected from paraquat-induced …

Ikaros Deficiency Leads To An Imbalance In Effector And Regulatory T Cell Homeostasis In Murine Pancreatic Cancer, Nadine D. Nelson

USF Tampa Graduate Theses and Dissertations

Pancreatic cancer is one of the deadliest cancers with a five-year survival rate of 6%. Pancreatic cancer is resistant to conventional chemotherapy and is usually diagnosed at late stages. Current treatment options have minimal effects in extending patients' lives beyond 10 months. One significant limitation in developing treatments to combat pancreatic cancer is its immunosuppressive microenvironment. Pancreatic cancer secretes factors that activate immunosuppressive cells, such as regulatory T cells (Tregs). These Tregs suppress effector CD4⁺ and CD8⁺ T cell anti-tumor immune responses. Therefore, novel treatment options to reduce Treg-mediated immune suppression and increase the numbers and functions of …

The Role Of Brct-Containing Proteins Brca1 And Paxip1 In Cancer, Ankita Jhuraney

USF Tampa Graduate Theses and Dissertations

Modular domains of proteins are important in cellular signaling processes. Eukaryotic cells are constantly undergoing DNA damage due to exogenous and endogenous sources of damage. The DNA damage response (DDR) involves a complex network of signaling events mediated by modular domains such as the BRCT (BRCA1 C-terminal) domains. Therefore, proteins containing BRCT domains are important for DNA damage detection and signaling. In this dissertation, we focus on two BRCT-containing proteins BRCA1 and PAXIP1. BRCA1 is a gene that is known to be associated with increased risk of hereditary breast and ovarian cancer. Germline variants of BRCA1 are assessed to determine …

Targeting T-Bet For Prevention Of Graft-Versus-Host Disease And Leukemia Relapse After Allogeneic Hematopoietic Stem Cell Transplantation, Jianing Fu

USF Tampa Graduate Theses and Dissertations

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective therapeutic option for many malignant diseases. However, the efficacy of allo-HSCT is limited by the occurrence of destructive graft-versus-host disease (GVHD). Since allogeneic T cells are the driving force in the development of GVHD, their activation, proliferation, and differentiation are key factors to understanding GVHD pathogenesis. On the other hand, antigen-presenting cells (APCs) are essential for allogeneic T-cell priming and the development of GVHD. The T-box transcription factor T-bet is a master regulator for IFN-γ production and Th1 differentiation. T-bet also regulates the functions of APCs including dendritic cells (DCs) and …

Novel Therapeutic Strategies In Lung Cancer, Courtney A. Kurtyka

USF Tampa Graduate Theses and Dissertations

Lung cancer is the leading cause of cancer-related death and the second most diagnosed cancer in the United States. Unfortunately, many patients either do not have any common mutations for which there are already targetable agents, or they eventually become resistant to these compounds. As such, there is a high demand for new, effective methods of treating this disease as well as predicting patient prognosis and potential benefit from chemotherapy. In this work, numerous strategies for treating lung cancer are explored.

The first method described here is through the use of a pan-early 2 factor (E2F) inhibitor, HLM006474, which is …

Mechanisms And Molecular Biology Of Major Tumor Suppressors, Brienne E. Engel

USF Tampa Graduate Theses and Dissertations

This dissertation is devoted to the study of the molecular biology of major tumor suppressors, defined as those that prevent the cellular processes identified as the hallmarks of cancer. Specifically, the major tumor suppressors pRb and STK11 are explored in the context of osteosarcoma and lung cancer, respectively.

RB1 was the first tumor suppressor gene discovered. Over four decades of work have revealed that the Rb protein (pRb) is a master regulator of biological pathways influencing virtually every aspect of intrinsic cell fate including cell growth, cell-cycle checkpoints, differentiation, senescence, self-renewal, replication, genomic stability and apoptosis. While these many processes …

Role And Regulation Of Snon/Skil And Plscr1 Located At 3q26.2 And 3q23, Respectively, In Ovarian Cancer Pathophysiology, Madhav Karthik Kodigepalli

USF Tampa Graduate Theses and Dissertations

Ovarian cancer is one of the most common causes of gynecological cancer related deaths in women. In 2014, the estimated number of deaths due to ovarian cancer is 14,270 with occurrence of over 22, 240 new cases (National Cancer Institute, http://seer.cancer.gov/statfacts/html/ovary.html). Despite improvement in treatment strategies, the 5-year survival rate is still below 50% mainly due to chemoresistance and relapse. Amplification of chromosomal region 3q26 is a common characteristic in various epithelial cancers including ovarian cancer. This region harbors various oncogenes including the TGFβ signaling mediators EVI1 and SnoN/SkiL, PKCι and PIK3CA amplified at 3q26.2 and 3q26.3, respectively, in ovarian …

Karst Estuaries: A Newly Described Ecosystem Governed By Aquifer Hydrology, Damian M. Menning

USF Tampa Graduate Theses and Dissertations

The overall goal of this dissertation is to define the hydrological, geochemical, and biological characteristics of a Karst Estuary. These types of estuaries represent a unique ecosystem created by freshwater inputs from direct flow through karst conduits and/or diffuse flow through a karst matrix. In order to determine the characteristics of a Karst Estuary we monitored short-term tidal fluctuations, long-term rainfall patterns, aquifer levels, spring discharge, multiple geochemical parameters, microbial communities in the water column and sediment, and macrofaunal communities in the sediment along a transect from a submarine spring through the Gulf of Mexico. Four sites were selected along …

Bi-Directional Signaling Between Melanoma And The Microenvironment Generates A Protective Niche That Mediates Therapeutic Escape, Inna Fedorenko

USF Tampa Graduate Theses and Dissertations

Very few cancer patients are cured through drug therapy alone, with the majority exhibiting acquired resistance. To date, most studies of therapeutic escape have focused upon tumor-intrinsic mechanisms of drug resistance with little attention paid to the role of normal host cells in preventing complete tumor eradication. In the present study we implicate co-operative bi-directional signaling between melanoma cells and fibroblasts in the generation of a pro-survival niche that mediates drug resistance. Mass-spectrometry based phosphoproteomics was used to show that BRAF inhibition and chemotherapy drugs enhanced the survival of both melanoma cells and fibroblasts through the induction of fibronectin (FN)/integrin …

Manipulating The Tumor Microenvironment For Therapeutic Benefit, Kate M. Bailey

USF Tampa Graduate Theses and Dissertations

The physical tumor microenvironment contributes significantly to carcinogenesis, cancer progression and metastatic dissemination. Two main components of the tumor microenvironment, hypoxia and acidosis, are present in nearly every solid tumor and act as powerful selection forces against the tumor. Hypoxia and acidosis promote tumor heterogeneity and contribute to chemotherapy and radiotherapy resistance. This dissertation interrogates methods to target the tumor microenvironment including two novel studies describing mechanisms of buffer therapy resistance and targeting tumor hypoxia with vasodilators to enhance the efficacy of a hypoxia activated prodrug, TH-302.

In the first study, mechanisms of buffer therapy resistance were identified and detailed. …

Regulatory Roles Of Facit Collagens Xii And Xiv In Cornea Stromal And Endothelial Development And Function, Chinda Hemmavanh

USF Tampa Graduate Theses and Dissertations

Purpose:

Corneal transparency depends upon the precise organization of corneal stromal extracellular matrix and corneal endothelial function. Stromal structure and extracellular matrix organization is responsible for proper refraction of light into the eye. The corneal endothelium is responsible for pumping excess fluid out of the cornea, effectively maintaining corneal hydration and thickness. Corneal transplantation is the current form of treatment for corneal endothelial and stromal dystrophies. The mechanisms controlling stromal collagen fibril packing and organization into orthogonal layers as well as maturation of the endothelium into a fully functioning cellular layer are unknown. Collagens XII and XIV, fibril associated collagens …

Characterization Of Iron Response In Gynecological Cell Lines, Kyle A. Bauckman

USF Tampa Graduate Theses and Dissertations

Ovarian carcinoma afflicts over 22,000 women each year with a 5 year survival rate of only 18% for stage IV patients [23]. Current treatment options are limited due to high rates of drug resistance and recurrence. Further, the identity of "precursor lesions" which give rise to various subclasses of epithelial ovarian cancer has been evasive. This is due to discovery of the cancer at already an advanced stage. Interestingly, endometriosis a benign but invasive gynecological disease has been described as a "precursor lesion" in the development of specific subtypes of ovarian cancer. Endometriotic cyst development involves the accumulation of "old …

Exploration Of Mutations In Erythroid 5-Aminolevulinate Synthase That Lead To Increased Porphyrin Synthesis, Erica Jean Fratz

USF Tampa Graduate Theses and Dissertations

5-Aminolevulinate synthase (ALAS; EC 2.3.1.37) is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that catalyzes the first committed step of heme biosynthesis in animals, the condensation of glycine and succinyl-CoA yielding 5-aminolevuliante (ALA), CoA, and CO2. Murine erythroid-specific ALAS (mALAS2) variants that cause high levels of PPIX accumulation provide a new means of targeted, and potentially enhanced, photosensitization. Transfection of HeLa cells with expression plasmids for mALAS2 variants, specifically for those with mutated mitochondrial presequences and a mutation in the active site loop, caused significant cellular accumulation of PPIX, particularly in the membrane. Light treatment of HeLa cells expressing mALAS2 variants revealed …

Immature Myeloid Cells Promote Tumor Formation Via Non-Suppressive Mechanism, Myrna Lillian Ortiz

USF Tampa Graduate Theses and Dissertations

ABSTRACT

Although there is ample evidence linking chronic inflammation with cancer, the cellular mechanisms involved in early events leading to tumor development remain unclear. Myeloid cells are an intricate part of inflammation. They consist of mature cells represented by macrophages, dendritic cells and granulocytes and a population of Immature Myeloid Cells (IMC), which in healthy individuals are cells in transition to mature cells. There is a substantial expansion of IMC in cancer and many other pathological conditions which is associated with pathologic activation of these cells. As a result, these cells acquire the ability to suppress immune responses and are …

Extracellular Proteases Are Key Mediators Of Staphylococcus Aureus Virulence Via The Global Modulation Of Virulence-Determinant Stability, Stacey L. Kolar, J. Antonio Ibarra, Frances E. Rivera, Joe M. Mootz, Jessica E. Davenport, Stanley M. Stevens Jr., Alexander R. Horswill, Lindsey N. Shaw

Molecular Biosciences Faculty Publications

Staphylococcus aureus is a highly virulent and successful pathogen that causes a diverse array of diseases. Recently, an increase of severe infections in healthy subjects has been observed, caused by community-associated methicillin-resistant S. aureus (CA-MRSA). The reason for enhanced CA-MRSA virulence is unclear; however, work suggests that it results from hypersecretion of agr-regulated toxins, including secreted proteases. In this study, we explore the contribution of exo-proteases to CA-MRSA pathogenesis using a mutant lacking all 10 enzymes. We show that they are required for growth in peptide-rich environments, serum, in the presence of antimicrobial peptides (AMPs), and in human blood. …

A Transient Α-Helical Molecular Recognition Element In The Disordered N-Terminus Of The Sgs1 Helicase Is Critical For Chromosome Stability And Binding Of Top3/Rmi1, Jessica A. Kennedy, Gary W. Daughdrill, Kristina H. Schmidt

Molecular Biosciences Faculty Publications

The RecQ-like DNA helicase family is essential for the maintenance of genome stability in all organisms. Sgs1, a member of this family in Saccharomyces cerevisiae, regulates early and late steps of double-strand break repair by homologous recombination. Using nuclear magnetic resonance spectroscopy, we show that the N-terminal 125 residues of Sgs1 are disordered and contain a transient α-helix that extends from residue 25 to 38. Based on the residue-specific knowledge of transient secondary structure, we designed proline mutations to disrupt this α-helix and observed hypersensitivity to DNA damaging agents and increased frequency of genome rearrangements. In vitro binding assays …