Life Sciences Commons^™

The Role Of Ykl-40 In The Progression Of Glioblastoma, Ralph Anthony Francescone

Open Access Dissertations

Glioblastoma Multiforme (GBM) is the most common brain cancer and one of the most fatal forms of cancer overall. The average survival time is 10-14 months, and less than 10% of patients survive more than 5 years after diagnosis. It is characterized by extreme vasculature, chemo/radioresistance, and invasiveness into the normal brain. The current standard of care, which includes surgical removal of tumor, radiation, and the chemotherapeutic agent temozolomide, initially stunt tumor growth. Nevertheless, the tumor invariably rebounds and the patient succumbs to the disease. Therefore, there is an urgent need to develop new therapies for this devastating disease.

YKL-40 …

Effects Of Phytochemicals From Rhodiola Crenulata On Highly Invasive Breast Cancer Cell Lines And Embryonic Models Of Migration, Adaris Rodriguez-Cortes

Open Access Dissertations

The root of the Tibetan plant Rhodiola crenulata is part of eastern traditional medicine. Studies have suggested that members of the Rhodiola genus display anticancer properties. In this study we examine the effect of R. crenulata in a cellular model of invasive breast cancer, this disease being the second cause of cancer death among women in the US. Deregulation of the Wnt/β-catenin pathway has been frequently observed in breast cancers and appears to have a key role in the transformation of benign cells to a malignant form. Although mutations of the Wnt growth factor are rarely observed in cancer, the …

Identification And Functional Characterization Of The Zebrafish Gene Quetschkommode (Que), Timo Friedrich

Open Access Dissertations

Locomotion in vertebrates depends on proper formation and maintenance of neuronal networks in the hind-brain and spinal cord. Malformation or loss of factors required for proper maintenance of these networks can lead to severe neurodegenerative diseases limiting or preventing locomotion. A powerful tool to investigate the genetic and cellular requirements for development and/or maintenance of these networks is a collection of zebrafish mutants with defects in motility. The zebrafish mutant quetschkommode (que) harbors a previously unknown gene defect leading to abnormal locomotor behavior. Here I show that the que mutants display a seizure-like behavior starting around four days post fertilization …

Target Recognition And Competitive Synaptogenesis In The Drosophila Giant Fiber System, Jason Joseph Hill

Open Access Dissertations

The development of complex neural networks relies on a careful balance of environmental cues to guide and shape both ends of the eventual connection. However, the correct wiring of circuits whose components share molecular profiles depends on a more elaborate phenomenon, competition. Despite being highly studied, there is still a lack of understanding as to the mechanism that allows molecularly identical cells to form exclusive connections with their targets. To address this complex question, we turned to a simple circuit within the genetically tractable fly. Responsible for the escape reflex, the Giant Fiber System is comprised of bilaterally symmetrical axons …

Components Of A Protein Machine: Allosteric Domain Assembly And A Disordered C-Terminus Enable The Chaperone Functions Of Hsp70, Robert G. Smock

Open Access Dissertations

Hsp70 molecular chaperones protect proteins from aggregation, assist in their native structure formation, and regulate stress responses in the cell. A mechanistic understanding of Hsp70 function will be necessary to explain its physiological roles and guide the therapeutic modulation of various disease states. To this end, several fundamental features of the Hsp70 structure-function relationship are investigated. The central component of Hsp70 chaperone function is its capacity for allosteric signaling between structural domains and tunable binding of misfolded protein substrates. In order to identify a cooperative network of sites that mediates interdomain allostery within Hsp70, a mutational correlation analysis is performed …

The Role Of The Suprmam1 Locus In Responses To Ionizing Radiation And Susceptibility To Mammary Tumors, Nicholas B. Griner

Open Access Dissertations

Loss of p53 function can lead to a variety of cancers, including breast cancer. Mice heterozygous for the p53 gene (designated Trp53+/-) develop spontaneous mammary tumors, but this depends on the strain background and has been linked to a locus on chromosome 7 (designated SuprMam1). Mammary tumors are common in BALB/c-Trp53+/-females, but are rare in C57BL/6-Trp53+/- mice. Prevalence of genomic instability appears to contribute to the phenotype as loss of heterozygosity (LOH) is significantly more common among tumors arising in BALB/c-Trp53+/- mice compared to C57BL/6J-Trp53+/- mice. This increased LOH in BALB/c-Trp53+/- tumors was shown to be due to recombination events. …

Xenopus Adam13 And Adam19 Are Important For Proper Convergence And Extension Of The Notochord, Russell David Neuner

Open Access Dissertations

Gastrulation is a fundamental process that reorganizes the primary germ layers to shape the internal and external features of an early embryo. Morphogenetic movements underlying this process can be classified into a variety of different types of cellular movements. I will focus on investigating in this thesis two types of cell movements in the dorsal mesoderm; mediolateral cell intercalation and convergence and extension. During gastrulation, mesoderm cells send protrusions to gain traction on neighboring cells and the surrounding extracellular matrix; a process called mediolateral cell intercalation. Mesoderm cells use this type of cell movement to converge and extend the dorsal …

Notch 1 Mediated Inhibition Of Nur77-Induced Apoptosis: Implications For T-Cell Leukemia, Jonathan George Rud

Open Access Dissertations

It is widely accepted that activating mutations of genes encoding the Notch family of transmembrane receptors, specifically Notch1, are associated with oncogenic transformation. Previous data from our lab has shown that an active form of Notch1 (NICD) provides protection against apoptosis in D011.10 T cells; and that this effect may be attributed to NICD binding the pro-apoptotic protein Nur77. Nur77 is an immediate early gene that is upregulated during both negative selection of thymocytes and activation-induced apoptosis in D011.10 T cells. Nur77 upregulation is tightly regulated and requires MEF2D, NFAT, and the transcriptional co-activator, p300, to effectively respond to apoptotic …

From Mouse Mammary Tumor Model To New Therapeutic Method ---Mammary Tumor Development In Balb/C-Trp53+/- Mice And Magnetic Nanoparticle Induced Heating For Cancer Treatment, Haoheng Yan

Open Access Dissertations

Mutation and loss of p53 function are common features among human breast cancers. We use BALB/c-Trp53+/- mice as a model to examine the sequence of events leading to mammary tumors. Mammary epithelium proliferation rates were similar in both BALB/c-Trp53+/- mice and wild type controls. Among the 28 mammary tumors collected from BALB/c-Trp53+/- mice, loss of heterozygosity for Trp53 was detected in more than 90% of invasive mammary tumors. Transplantation of Trp53+/- ductal hyperplasias indicated an association between loss of the wild type allele of Trp53 and progression to invasive carcinomas. Expression of biomarkers such as ERα, PR, Her2/Neu and activated …

New Insights In The Tssk Family: Studies In The Activity And Function Of The Testis Specific Serine Kinases, Julian Sosnik

Open Access Dissertations

The Testis Specific Serine Kinase (Tssk) family of proteins is a large group of kinases that present high level of conservation within paralogs, as well as within species. In addition, in all reported cases as well as in the analysis of expressed sequence tags available in databases, this family of proteins presents a very strict pattern of either testicular or male-gonadal expression. This high level of conservation prompted the postulate that these kinases ought to be important for either testicular function or fertilization. In this work we attempt a biochemical characterization of one family member (Tssk6) in the mouse. We …

Beyond Cell Adhesion: Exploring The Role Of Cadherin-11 Extracellular Processing By Adam Metalloproteases In Cranial Neural Crest Migration, Catherine D. Mccusker

Open Access Dissertations

The migration of the cranial neural crest is an essential part of cranio-facial development in every vertebrate embryo. The cranial neural crest (CNC) is a transient population of cells that forms the lateral border of the anterior neural plate. In the tailbud stage Xenopus embryo, the neural crest cells delaminate from the neural tube, and undergo a large-scale migration from the dorsal to ventral region of the embryo. The CNC travels along distinct pathways, and populates specific regions of the embryos face. Once the CNC ceases migrating, it differentiates into a variety of tissues that are essential for cranio-facial structure …

The Role Of Runx1 N-Terminal Splice Isoforms In Hematopoietic Development, Emmett E. Hedblom

Open Access Dissertations

Runx1/AML1 transcription factor expression in hematopoietic cell lineages is differentially regulated via usage of two distinct promoters. The 5' UTR and a 19 amino acid encoding sequence transcribed from the distal promoter is inserted via alternative splicing into the 5' end of the mRNA transcript, replacing the 5' UTR and a 5 amino acid encoding sequence usually transcribed from the proximal promoter. Expression of proximal Runx1 in 32Dcl.3 cells delays G-CSF induced neutrophil terminal differentiation by increasing viability compared to distal Runx1. We utilized Runx1 Nterminal deletion and point mutants of three evolutionarily conserved residues to describe dual N-terminal isoform …

Delayed Anesthetic Preconditioning And Metallothioneins I+Ii: Novel Mediators Of Anesthetic-Induced Protection, Scott David Edmands

Open Access Dissertations

Ischemic injury is a common and debilitating outcome of natural illness and as a complication of commonly performed medical procedures. Whereas naturally occurring ischemic insults are often the result of unpredictable events, such as in the case of stroke or heart attack, the risk of operative and perioperative ischemia is somewhat better characterized in the clinical setting. Given the prevalence and severity of outcomes in ischemic injury, there is significant interest in developing better pharmacological and procedural approaches to improve patient outcomes. One approach that has shown significant promise in the laboratory setting, particularly in the context of planned medical …

Modulation Of Macrophage Responses To Borrelia Burgdorferi In Acute Murine Lyme Carditis, Chris Martin Olson

Open Access Dissertations

The Lyme disease spirochete Borrelia burgdorferi is the only known human pathogen that directly activates invariant natural killer T (iNKT) cells. The number and activation kinetics of iNKT cells vary greatly among different strains of mice. Here, we report the role of the iNKT cell response in the pathogenesis of Lyme disease using C57BL/6 (B6) mice, a strain with optimal iNKT cell activation that is resistant to the development of spirochetal-induced inflammation. During experimental infection of B6 mice with B. burgdorferi , iNKT cells localize to the inflamed heart where they are activated by CD1d-expressing macrophages. Activation of iNKT cells …

The Conformational Gymnastics Of The Escherichia Coli Seca Molecular Machine And Its Interactions With Signal Sequences, Jenny Lynn Maki

Open Access Dissertations

Protein secretion is a selective and regulated process that is essential in all organisms. In bacteria the preprotein translocase SecA, either free in the cytosol or associated with the SecYEG translocon, recognizes and binds most post-translational secretory proteins containing an N-terminal signal sequence. In Gram-negative bacteria, the molecular chaperone SecB binds many of the preproteins to keep them in a translocation-competent state. Subsequently, SecB delivers the preproteins to the translocon-associated SecA, which binds the signal sequence and also interacts with mature regions of the preprotein. After the preprotein/SecA/SecYEG complex has formed, the energy derived from ATP hydrolysis by SecA coupled …