Cell Biology Commons^™

Loss Of Rap1gap: A Driver In The Progression From Dcis Of The Breast To Idc, Seema Shah

Wayne State University Dissertations

The purpose of this study is to determine the role of Rap1Gap in the progression of DCIS (ductal carcinoma in situ) to IDC (invasive ductal cancer). We employed an in-vitro three-dimensional (3D) overlay model that provides a physiologically relevant microenvironment to study mechanisms of malignant progression. Previous studies from this laboratory aimed to determine specific gene expression changes common to three models of DCIS- MCF10.DCIS, SUM 102 and SUM 225 in comparison to MCF10A cells, a model of non-transformed human mammary epithelium. The expression of 295 genes was found to be significantly altered, with 63 being increased in expression in …

Defining And Characterizing The Step In The Hiv-1 Viral Life Cycle Affected By Fullerene Derivatives, Zachary Sean Martinez

Open Access Theses & Dissertations

Fullerene derivatives, both C60 and C70, were synthesized and characterized to test their activity against HIV-1 infection. The derivatives tested have previously been reported to inhibit HIV-1 replication and/or in vitro activity of reverse transcriptase. It was found that viruses produced in the presence of low micromolar concentrations of most of these fullerene derivatives exhibit a reduction in viral infectivity greater than 99%. Quantification of virion-associated viral RNA and p24 indicates that RNA packaging and viral production were unremarkable in these viruses. These compounds did not affect infectivity of mature virions, indicating no effect on the early steps of the …

Elucidating The Molecular Mechanism Of Action By Which Rs1-208b Induces Apoptosis In Hematological Cancers, Ruben Israel Calderon

Open Access Theses & Dissertations

The 26S proteasome has been successfully targeted to treat multiple myeloma. However, the effect can sometimes be reversed as cells acquire resistance to chemotherapy. Recently, combining proteasome inhibitors with indirect proteasome inhibitors has been proposed in order to delay and even reverse resistance. Small molecules derived from 4-piperidinone that maintain an unsaturated β-carbonyl group are thought to interact with the thiol group of catalytically active cysteine residues in deubiquitinases that associate with the 26S proteasome, effectively inhibiting the proteasome.

RS1-208b was selected following a high-throughput screening of a small library of 4-piperidinone derived curcumin structural analogs due to its selectivity …

The Impact Of Altered T Cell Receptor—Peptide-Major Histocompatibility Complex Interactions On Antigen Recognition And T Cell Function, Timothy T. Spear

Dissertations

Adoptive cell transfer (ACT) using T cell receptor (TCR) gene-modified T cells is an exciting and rapidly evolving field. Numerous basic science and clinical studies have demonstrated various levels of feasibility, safety, and efficacy using TCR-engineered T cells to treat cancer and viral infections. Genomic instability of targeted diseases, however, requires effective and safe TCRs to cross-recognize mutated antigens while minimizing on- or off-target toxicities. Thus, improvements to T cell-based therapeutics mandate a broader understanding of the principles governing antigen recognition. This dissertation addresses critical biologic questions evaluating which parameters are most important in facilitating antigen recognition, and how alterations …

Homocysteine And Csrp-3 Protein In Migrating Neural Crest Cells: A Quantitative And Qualitative Confocal Microscopy Study, Allysan R. White

Dissertations and Theses @ UNI

Congenital heart defects are one of the leading causes of infant death. High maternal blood serum levels of the amino acid homocysteine and the frequency of heart defects are correlated, but the immediate cause is unknown. During early embryonic development, a distinctive population of cells arises dorsally as the neural tube closes, forming the brain and spinal cord. These are the neural crest cells, which play a crucial role in the development of the nervous system, head skeletal, certain endocrine and connective tissues, and, notably, the heart’s outflow region. These migratory cells will follow specific pathways and respond to signals …

Characterizing An Alternative Chloroplast Outer Membrane Targeting Signal In Arabidopsis Thaliana, Nicholas A. Grimberg

Theses and Dissertations (Comprehensive)

Chloroplasts are organelles that are unique to plant and algal cells and are the site of photosynthesis. Though chloroplasts contain their own genome, an estimated 95% of chloroplast proteins are encoded in the nucleus, and therefore rely on post-translational targeting to the organelle. The majority of known chloroplast proteins are targeted to the chloroplast interior by cleavable signals at the N-terminal end of preproteins known as transit peptides. The translocon at the outer envelope membrane of chloroplasts (Toc) is a multimeric complex that recognizes and binds N-terminal transit peptides at the cytosolic surface of chloroplasts. Though transit …

Comparative Proteomic Analysis Of Extracellular Vesicles From Prostate Cancer-Derived Cell Lines, Gloria Polanco

Open Access Theses & Dissertations

Prostate cancer (PCa) is the leading non-cutaneous malignancy and the second deadliest among American men. PCa mortality rates among African American men are much higher than any other ethnic group, and the same is true for men of African ancestry world-wide. There is also a lack of reliable diagnostic markers and effective treatment options. Extracellular vesicles (EVs) have been observed to play an important role in cancer processes such as promotion of tumor growth and metastasis. They are also a promising source of diagnostic markers. This study addresses these problems by studying the proteome of EVs derived from PCa cells …

The Role Of Tumor Suppressor Co-Chaperone Chip/Stub1 In Erbb2-Mediated Oncogenesis, Haitao Luan

Theses & Dissertations

The epidermal growth factor receptor (EGFR) family member ErbB2 (Her2) is overexpressed in 20 -30% of invasive breast cancers and this overexpression correlates with poor prognosis and shorter overall as well as disease-free survival. Aberrant expression of ErbB2 through gene amplification, transcriptional deregulation and/or altered endocytic trafficking results in overexpression of ErbB2 at the plasma membrane and biases ErbB2 from primarily ligand-driven hetero-dimerization under normal expression conditions to increased ligand-independent homo-dimer and hetero-dimer formation and consequent activation. C-terminus of HSC70-Inteeracting protein (CHIP)/STIP1-homologous U-Box containing protein 1 (STUB1) is an HSP90/HSC70 interacting negative co-chaperone known to promote ubiquitination and degradation of …

A Role For Ehd Family Endocytic Regulators In Endothelial Biology, Alexandra E. J. Moffitt

Theses & Dissertations

Endocytic trafficking is an essential process in eukaryotic cells, specifically for the transport of nutrients, membrane components, and receptors. Cargo destined for endocytic traffic is internalized at the cell surface via clathrin-dependent and clathrin-independent pathways, and brought to the early or sorting endosomes. From there, cargo is further trafficked to lysosomes for degradation, trafficked to other compartments in the cell, or recycled back to the cell surface (either directly or via the endocytic recycling compartment).

Mammalian C-terminal Eps15 homology domain-containing proteins, or EHD proteins (EHD1 to 4), are a family of highly conserved ATPases that function as key regulators of …

Acute Methamphetamine Exposure Affects Histone Modifying Enzymes And Cytokine Production In Macrophages, Ariel Burns

Theses & Dissertations

The effects of methamphetamine (Meth) in the periphery are not well studied and a comprehensive investigation on the effects and molecular mechanism will give insight into why Meth users are at an increased risk of infections. For this reason, we use macrophages as a model for the immune system dysregulation seen in Meth abusers and also because macrophages are a long-lived cell that HIV infects and persists in. We aimed to determine the effects of Meth on the cytokine production, histone modifying enzymes and the corresponding histone post-translational modifications, and the molecular mechanism in HIV-infected human macrophages treated with combination …

Parn Deadenylase Is Involved In Mirna-Dependent Degradation Of Tp53 Mrna In Mammalian Cells, Xiaokan Zhang, Emral Devany, Michael R. Murphy, Galina Glazman, Mirjana Persaud, Frida E. Kleiman

Publications and Research

mRNA deadenylation is under the control of cis-acting regulatory elements, which include AU-rich elements (AREs) and microRNA (miRNA) targeting sites, within the 3′ untranslated region (3′ UTRs) of eukaryotic mRNAs. Deadenylases promote miRNA-induced mRNA decay through their interaction with miRNA-induced silencing complex (miRISC). However, the role of poly(A) specific ribonuclease (PARN) deadenylase in miRNA-dependent mRNA degradation has not been elucidated. Here, we present evidence that not only ARE- but also miRNA-mediated pathways are involved in PARN-mediated regulation of the steady state levels of TP53 mRNA, which encodes the tumor suppressor p53. Supporting this, Argonaute-2 (Ago-2), the core component of miRISC, …

Is The Zebrafish Zombie Mutant Caused By A Mutation In Cdc20?, Peyton Johnston

Honors Theses

The zombie mutant was identified as an early arrest mutant, stopping in development around the 10-somite stage (14 hours of development). Further inspection revealed that this mutant was a cell cycle mutant and cells in the mutant arrest during metaphase as early as the 5-somite stage (11.6 hours of development). A similar phenotype is seen in the Drosophila melanogaster cell cycle gene fizzy, known to be to be a homolog of the Saccharomyces cerevisiae gene, cell division cycle 20 (cdc20). CDC20 is an activator protein of the anaphase promoting complex/cyclosome (APC/C), an ubiquitin E3 ligase that is …

The Development Of A Platform For Expression And Purification Of The Mammalian Transmembrane Transporter Abca4, Amaryllis Ortiz

Graduate School of Biomedical Sciences Theses and Dissertations

Purpose- ABCA4 is an ATP Binding Cassette (ABC) protein localized at cone and rod photoreceptor outer segments of the retina. Though mutations in ABCA4 have been found to cause a broad spectrum of disorders, ABCA4's high molecular weight (~210 kDa) and biochemical transmembrane properties have made ABCA4 functional studies unsuccessful. Identifying how ABCA4 functions might have significant clinical impact and open unanticipated avenues for therapeutic interventions. Thus, the objective of this study was to develop a new expression system able to produce the full-length, correctly folded and fully functional ABCA4 protein.

Methods- the ABCA4 gene was amplified from the PCMV6-ABCA4 …

The Role Of G-Protein Signaling In Pathogenesis In Cercospora Zeae-Maydis, Brant Smith

Graduate Theses and Dissertations

Gray leaf spot, caused by Cercospora zeae-maydis, is one of the most destructive foliar diseases of maize worldwide. C. zeae-maydis orients hyphal growth towards stomata (stomatal tropism) and forms infectious structures (appressoria) that are necessary for successful infection. Although some genes involved in pathogenesis in C. zeae-maydis have been identified, the molecular mechanisms are not well understood. In fungi, heterotrimeric G-proteins consist of three subunits (α, β, and γ) and mediate responses to environmental stimuli. They regulate diverse functions, including nutrient detection, virulence, fungal development, conidiation, secondary metabolism, and pathogenesis in many plant pathogenic fungi. This research explored the role …

The Effect Of Leucine Supplementation On Mitochondrial Biogenesis And Mitochondrial Protein Synthesis In Rats Fed A High-Fat Diet, David M. Skinner

Health, Human Performance and Recreation Undergraduate Honors Theses

This study aims to illuminate interaction between leucine supplementation and mitochondrial proteins concerned with synthesis and biogenesis. We hypothesized that supplementation with leucine will attenuate the weight gain of the high fat diet in comparison with the normal chow group, by enhancing mitochondrial biogenesis and content. We conducted a laboratory experiment using Western Blotting techniques to determine protein expression. Proteins of interest in this study include PGC-1α, COX-IV, TUFM, TFAM, and mtIF2. The findings from the research show a main effect of an increase in the expression of PGC-1 α in high fat diets. There was no difference in the …

Characterization Of Embryonic Stem Cell-Differentiated Cells As Mesenchymal Stem Cells, Rachael N. Kuehn

Honors Theses

Embryonic stem cells (ESCs), due to their ability to differentiate into different cell types while still maintaining a high proliferation capacity, have been considered as a potential cell source in regenerative medicine. However, current ESC differentiation methods are low yielding and create heterogeneous cell populations. If transplanted in the human body, differentiated ESCs could be rejected by the immune system, form tumors, or may not function normally within the human body. On the other hand, mesenchymal stem cells (MSCs), a type of adult stem cell typically derived from bone marrow, have proved to be excellent candidates in clinical applications due …

Preventing Thymus Involution In K5.Cyclin D1 Transgenic Mice Sustains The Naïve T Cell Compartment With Age, Michelle L. Bolner

Dissertations and Theses (Open Access)

The thymus maintains T cell receptor (TCR) repertoire diversity through perpetual release of self-MHC restricted naive T cells. However, thymus involution during the aging process reduces naïve T cell output, leading to defective immune responsiveness to newly encountered antigens. We have found that early thymus involution precipitates the age-associated shift favoring memory T cell dominancy in young control mice. Furthermore, we have shown that age-related thymus involution is prevented in mice expressing a keratin 5 promoter-driven Cyclin D1 (K5.D1) transgene in thymic epithelial cells (TECs). Thymopoiesis occurs normally in K5.D1 transgenic thymi and sustains T cell output to prevent the …

Role Of Stat3 In Human Nk Cell Functions, Prasad V. Phatarpekar

Dissertations and Theses (Open Access)

Natural Killer (NK) cells are cytotoxic lymphocytes, which play a critical role in the immune response against malignant cells and microbial infections. NK cells are equipped with activating receptors, which upon detecting ligands expressed on stressed cells induce cytolytic activity of NK cells. Stimulation of NK cell proliferation and priming of NK cytolytic capability are accomplished by cytokines, which mediate their signals mainly through JAK-STAT signaling pathway. Previously, we found that K562 cells genetically modified to express membrane bound IL-21 (mbIL-21), which predominantly activates STAT3, induce robust expansion and activation of human NK cells. Further investigations revealed role of STAT3 …

The Tumor Suppressor Notch Inhibits Head And Neck Squamous Cell Carcinoma (Hnscc) Tumor Growth And Progression By Modulating Proto-Oncogenes Axl And Ctnnal1 (Α-Catulin), Shhyam Moorthy, Shhyam Moorthy

Dissertations and Theses (Open Access)

Background: Head and Neck Squamous Cell Carcinoma (HNSCC) is the sixth most common malignancy worldwide, with roughly 300,000 cancer related deaths occurring globally each year. The survival of patients with HNSCC has not changed significantly over the past decade, leading investigators to search for promising molecular targets. To identify new treatment targets and biomarkers that could better guide therapy, we previously characterized the genomic alterations from primary HNSCC patient samples. We were among the first to discover that NOTCH1 is one of the most frequently mutated genes in this cancer type. The spectrum of inactivating NOTCH1 mutations in HNSCC suggested …

Normal Glycolytic Enzyme Activity Is Critical For Hypoxia Inducible Factor-1a Activity And Provides Novel Targets For Inhibiting Tumor Growth, Geoffrey Grandjean Phd

Dissertations and Theses (Open Access)

Normal Glycolytic Enzyme Activity is Critical for Hypoxia Inducible Factor-1α Activity and Provides Novel Targets for Inhibiting Tumor Growth

By Geoffrey Grandjean

Advisory Professor: Garth Powis, D. Phil

Unique to proliferating cancer cells is the observation that their increased need for energy is provided by a high rate of glycolysis followed by lactic acid fermentation in a process known as the Warburg Effect, a process many times less efficient than oxidative phosphorylation employed by normal cells to satisfy a similar energy demand ^[1]. This high rate of glycolysis occurs regardless of the concentration of oxygen in the cell and …