Cell and Developmental Biology Commons^™

Targeting Of The Hedgehog Signaling Pathway In Cancer Treatment, Andrew J. Hawes

The Cardinal Edge

The Hedgehog (Hh) signaling pathway is a developmental pathway that is highly conserved evolutionarily. While typically only displaying high activity during embryogenesis, overactivation of the Hh pathway in adults has been linked to multiple forms of cancer including acute myeloid leukemia, myelofibrosis, basal-cell carcinoma, pancreatic ductal adrenal carcinoma, and triple negative breast cancer. The prevalence of Hh activation in many different cancers has made it a prime target for inhibition of these cancers through novel therapies. This literature review sought to assess the current state of cancer treatment through inhibition of Hh signaling. Most current clinical trials involving the pathway …

Planning System For The Optimization Of Electric Field Delivery Using Implanted Electrodes For Brain Tumor Control, Erin Iredale, Brynn Voigt, Adam Rankin, Kyungho W Kim, Jeff Z Chen, Susanne Schmid, Matthew O Hebb, Terry M Peters, Eugene Wong

Anatomy and Cell Biology Publications

BACKGROUND: The use of non-ionizing electric fields from low-intensity voltage sources (< 10 V) to control malignant tumor growth is showing increasing potential as a cancer treatment modality. A method of applying these low-intensity electric fields using multiple implanted electrodes within or adjacent to tumor volumes has been termed as intratumoral modulation therapy (IMT).

PURPOSE: This study explores advancements in the previously established IMT optimization algorithm, and the development of a custom treatment planning system for patient-specific IMT. The practicality of the treatment planning system is demonstrated by implementing the full optimization pipeline on a brain phantom with robotic electrode implantation, postoperative imaging, and treatment stimulation.

METHODS: The integrated planning pipeline in 3D Slicer begins with importing and segmenting patient magnetic resonance images (MRI) or computed tomography (CT) images. The segmentation process is manual, followed by a semi-automatic smoothing step that allows …

Function Of Atm And Msh2 During Dna Repair And Recombination, Emily Sible

Dissertations, Theses, and Capstone Projects

Class switch recombination (CSR) produces secondary immunoglobulin isotypes and requires AID-dependent DNA deamination of intronic switch (S) regions within the immunoglobulin heavy chain (Igh) gene locus. Non-canonical repair of deaminated DNA by mismatch repair (MMR) or base excision repair (BER) creates DNA breaks that permit recombination between distal S regions. ATM-dependent phosphorylation of AID at serine-38 (pS38-AID) promotes its interaction with APE1, a BER protein, suggesting that ATM regulates CSR through BER. However, pS38-AID may also function in MMR during CSR, although the mechanism remains unknown. To examine whether ATM modulates BER- and/or MMR-dependent CSR, Atm^-/- mice …

Isolation And Characterization Of Fluorescent Proteins And Small Molecules From Marine Vertebrates, Sara Rose Krivoshik

Dissertations, Theses, and Capstone Projects

Fluorescence is a phenomenon in which a wavelength of light excites a fluorophore and then emits light at a higher, longer wavelength. This occurs throughout the biological world, in both the terrestrial and marine realms. Encompassing a diverse set of mechanisms from small molecules to large protein complexes; fluorescence has been used as a biological tool with a wide range of applications to study molecular and cellular biology for decades. This dissertation looks to identify and characterize novel fluorescent proteins and small molecules to allow for more efficient translation in developing new biotechnologies. Using a combination of RNA-Seq, Mass-Spec, protein …

Determining The Roles Of The Oligomerization And C-Terminal Domains In Mutant P53 Gain-Of-Function Activities, George K. Annor

Dissertations, Theses, and Capstone Projects

The tumor suppressor p53 (TP53) gene is often mutated in cancer, with missense mutations found in the central DNA binding domain, and less often in the oligomerization domain (OD) and C-terminal domain (CTD). The OD and CTD have been found to be critical for the tumor suppressor functionality of wild-type p53 (wtp53). Specific missense mutations in the DNA binding domain have been found to confer new gain-of-function (GOF) activities. Mutations that destabilize tetramer formation, or deletion of key lysine residues within the CTD, downregulate the ability of wtp53 to transactivate (increase the rate of transcription of) its target …

Gamma Protocadherin Synaptic Localization And Intracellular Trafficking Is Consistent With Distinct Adhesive And Anti-Adhesive Roles In Development, Nicole Lamassa

Dissertations, Theses, and Capstone Projects

Clustered protocadherins (Pcdhs) constitute a family of cell adhesion molecules with approximately 60 Pcdh genes clustered in a 1 MB locus on chromosome 5q31 in humans. The Pcdh gene cluster is subdivided into α, β, and γ subclusters which encode related proteins. Individual neurons activate different subsets of Pcdh-α, Pcdh-β and Pcdh-γ genes by epigenetic mechanisms to generate distinct Pcdh adhesive units expressed by each neuron. This is thought to serve as a “surface barcode” for single-cell identity and synaptic recognition in the nervous system. The actual role for Pcdhs in neural development is still relatively unknown and different roles …

Clustered Protocadherins Ubiquitination And Phosphorylation Regulates Surface Expression, Albert Ptashnik

Dissertations, Theses, and Capstone Projects

Clustered protocadherins (Pcdhs) are a family of 60 adhesion-like molecules forming a neural barcode. In vertebrate neurons, 60 Pcdhs are coded by a large gene cluster. Numerous axons in the cluster are coding for the different extracellular, transmembrane, variable portion of the cytoplasmic and constant cytoplasmic domains where their expression is controlled epigenetically. These proteins mediate interactions between axons, dendrites, and glial cells during neural development. Yet, Pcdhs are not strictly adhesion molecules. In the amacrine cells of the retina, Pcdhs promote avoidance of the same cell dendrites, where in the cortex Pcdhs promote interactions between dendrites and astrocytes. In …

Investigating The Role Of The Transcriptional Coregulator Cited2 In Regulating Intermediate Progenitor Proliferation And Modulating Behavior, Nikolaus R. Wagner

Dissertations - ALL

The mammalian neocortex develops from a thin layer of neuroepithelial cells into a robust mosaic of differentiated neurons organized into distinct layers and functional areas. This process requires a complex choreography of transcription factors and epigenetic regulators to be spatially and temporally activated in a precise manner. Disruptions in any aspect of this delicate process may lead to neurodevelopmental disorders like autism spectrum disorder, schizophrenia, or intellectual disability. One such transcriptional coregulator that is a crucial regulator of neocortical development is Cited2. Previous work demonstrated that forebrain-specific Cited2 loss-of-function causes a reduction in neocortical progenitor proliferation which leads to reduced …

Investigating The Effects Of Cell Signaling Mutants And Inhibitors On Chemokinesis In Dictyostelium Discoideum., James Rybczyk

Honors Scholar Theses

Chemokinesis is the augmentation of cellular motility in response to chemical stimuli. While it is known that chemical factors induce changes in the behavior of a cell with regards to motility, the mechanism by which this process occurs is poorly understood. The aim of this project is to identify potential proteins within the signaling pathways that integrate the message brought on by chemical ligands and consequently lead to changes in cellular motility. In order to accomplish this goal, various gene knockout mutants of the amoeboid species Dictyostelium discoideum are compared to an axenic wild-type strain (AX2) based on their relative …

Arabidopsis Shoot Gravitropism Requires The Mediator Coactivator Complex, Gabriella Newton

Honors Theses

Gravitropism is a plant response to gravity in directing the growth of its organs, such as the root and the stem. Gravity is sensed by statocytes, unique cells that contain starch-filled amyloplasts, which trigger gravitropic growth response by modulating the distribution of growth hormone auxin in the elongation zone of the stem and root. Despite the fact that multiple factors have been identified as key regulators of shoot negative gravitropism, how these factors are regulated at the transcriptional level is largely unknown. In this study, we explore the role of transcriptional machinery in regulating shoot gravity sensing and responses by …

Mechanisms And Roles Of Dynamic Actin Assembly Around Dysfunctional Mitochondria, Tak Shun Fung

Dartmouth College Ph.D Dissertations

Possessing the ability to efficiently generate ATP required to sustain cellular functions, mitochondria are often considered the ‘powerhouses of the cell’. However, our understanding of mitochondria in cell biology was further expanded when we recognized that communication between this unique organelle and the rest of the cell regulates cellular bioenergetics, metabolism and signaling processes such as mitophagy and apoptosis. Here, I investigate signaling between mitochondria and the actin cytoskeleton, and how this signaling regulates mitochondrial dynamics and cellular function. Specifically, I find that, upon mitochondrial dysfunction, actin polymerizes rapidly around the dysfunctional organelle, which we term ‘acute damage-induced actin’ (ADA). …

Nup211 Plays An Important Role In Regulating Mrna Export And Stress Response, Ayana Ikenouchi

Theses and Dissertations

Nup211 is a nuclear pore basket component in Schizosaccharomyces pombe and roles in the gating functions of NPCs. Using RT-qPCR, I found that in nup211-shutoff cells, the transcript levels of genes in mRNA export and stress-response pathways were significantly changed, suggesting nup211 is involved in regulating stress response pathways.

Mechanisms Of Carbapenemase-Mediated Resistance Among High-Risk Pseudomonas Aeruginosa Lineages In Peru, Isabella A. Tickler, Juan Carlos Gomez De La Torre, Luis Alvarado, Anne E. Obradovich, Fred C. Tenover

Biology Faculty Publications

Objectives: Pseudomonas aeruginosa is one of the leading causes of healthcare-associated infections globally. High-risk carbapenemase-encoding P. aeruginosa clones are disseminating in many regions. The aim of this study was to learn more about the lineages and mechanisms of resistance of P. aeruginosa circulating in Peru.

Methods: A total of 141 carbapenemase-producing isolates recovered from hospitalized and ambulatory patients in Lima were sequenced and analyzed to infer their lineages through whole-genome sequence typing (wgST) and to identify their antimicrobial resistance genes.

Results: wgST identified nine sequence types (STs); ST111 and ST357 were the most frequently encountered (44.0% and 38.3%, respectively), followed …

Establishing The Freestyle 293 Expression System As A Tool To Generate Recombinant Apolipoprotein E In Mammalian Cells, Michaela Cunningham

Honors Program Theses and Projects

Alzheimer’s disease (AD) is a devastating form of dementia with 5 million people suffering from the disease in the United States alone. Thus, there is a need to understand the cause of AD so that therapeutics can be developed to treat it. The greatest risk factor for AD is the APOE gene, which encodes the apolipoprotein Eprotein. Three predominant APOE alleles exist humans, which give rise to three isoforms, called apoE2, E3, and E4. Individuals with apoE4 are ten times more likely to develop AD. In contrast, the apoE2 isoform has a neuroprotective effect and is associated with a 2-fold …

Characterization Of Exosomes And Their Role In Cellular Migration In Chemosensitive And Chemoresistant Ovarian Cancer Cells, Courtney Mceneaney

Honors Program Theses and Projects

Chemotherapy-resistant cells that remain after primary cancer treatment lead to recurrence and metastasis, resulting in a poor prognosis for patients. Chemoresistant cells were created by our collaborators using the human ovarian cancer cell line, OVCAR8, by selection of cells that survived serial culture with cisplatin, a platinum-based chemotherapeutic. The cisplatin-resistant cells (OVCAR8R) demonstrate a morphology unique from the original cisplatin-sensitive cells (OVCAR8) which could correlate with their difference in aggressiveness. My research goal is to isolate and characterize exosomes from the OVCAR8 and OVCAR8Rlines. Exosomes are small vesicles secreted from cells and contribute to the tumor microenvironment(TME). It has been …

Post-Transcriptional Control Of The Epithelial-To-Mesenchymal Transition (Emt) In Ras-Driven Colorectal Cancers, Chaitra Rao

Theses & Dissertations

Colorectal cancer (CRC) originates from epithelial cells lining the colon or rectum of the gastrointestinal tract. Most cancer deaths result from a tumor spreading to distant organs; however epithelial cells do not normally migrate from their tissue of origin. To do so, epithelial cells undergo biochemical changes allowing them to acquire behavior similar to motile mesenchymal cells termed the epithelial-to-mesenchymal transition (EMT), which contributes to tumor invasion and metastasis. Our study demonstrated that CRC cells require a molecular scaffold, Kinase Suppressor of Ras 1 (KSR1), and ERK to promote the EMT-like phenotype through the preferential translation of Epithelial Stromal Interaction …

Dysregulation Of Mir-10a Promotes Cancer Features In Cholangiocarcinoma, Matthieu Spriet

Theses & Dissertations

Cholangiocarcinoma is a primary liver cancer of the bile duct epithelium that exhibits microRNA-mediated control of tumor cell signaling. Strides toward new treatment rest on a better defining of cholangiocarcinoma tumor biology including the RNA-based layer of regulation. Additionally, there is a gap in knowledge on microRNA expression in human tissue. While there is RNA-seq data of microRNA expression in tissue, it does not differentiate between cell types, thus leaving unanswered questions about cell specific microRNA biology and expression.

Here, we identify miR-10a as an oncogenic microRNA acting through MAPK signaling. Using cholangiocarcinoma cell lines, we determined miR-10a is an …

Investigating The Role Of Splenic Macrophages In Pancreatic Cancer, Daisy V. Gonzalez

Theses & Dissertations

Pancreatic cancer is currently the 3rd leading cause of all cancer-related deaths, with a 5-year survival rate remaining at 10%. The current standard treatment of care and a lack of effective diagnostic markers leaves patients with a dismal prognosis at advanced stages of the disease. This thesis research evaluated the effect of ApoE-expressing macrophages in the spleen. First, we aimed to assess the ApoE expression in the spleen of pancreatic tumor-bearing mice. Results showed that ApoE expression in splenic macrophages increased as the disease progressed. In addition, we saw a significant increase in marginal zone metallophilic macrophages and red pulp …

Ewing Sarcoma Transcriptome: Identification Of Foxn3 As A Novel Target Of Ews-Fli1, Natasha Kreiling

Theses & Dissertations

Ewing Sarcoma is an aggressive cancer characterized by a fusion gene formed from a chromosomal translocation between a RNA binding protein and a transcription factor. The most common fusion gene is EWS-FLI1 a potent oncogenic transcription factor responsible for initiating genome instability. EWS-FLI1 promotes tumor growth by dysregulating several genes and pathways. We have identified FOXN3, an important gene in cell cycle control and development, as being suppressed by EWS-FLI1. In the future, a better understanding of FOXN3 and its ability to act as a tumor suppressor in EWS will unravel novel mechanisms of EWS pathogenesis, potential biomarker and drug …

Subtype-Selective Positive Modulation Of KCa2.3 Channels Increases Cilia Length, Young-Woo Nam, Rajasekharreddy Pala, Naglaa Salem El-Sayed, Denisse Laren-Henriquez, Farideh Amirrad, Grace Yang, Mohammad Asikur Rahman, Razan Orfali, Myles Downey, Keykavous Parang, Surya M. Nauli, Miao Zhang

Pharmacy Faculty Articles and Research

Small-conductance Ca²⁺-activated potassium (K_Ca2.x) channels are gated exclusively by intracellular Ca²⁺. The activation of K_Ca2.3 channels induces hyperpolarization, which augments Ca²⁺ signaling in endothelial cells. Cilia are specialized Ca²⁺ signaling compartments. Here, we identified compound 4 that potentiates human K_Ca2.3 channels selectively. The subtype selectivity of compound 4 for human K_Ca2.3 over rat K_Ca2.2a channels relies on an isoleucine residue in the HA/HB helices. Positive modulation of K_Ca2.3 channels by compound 4 increased flow-induced Ca²⁺ signaling and cilia length, while negative …