Cancer Biology Commons^™

Investigating The Phenotypic Effects Of Ring1- And Yy1-Binding Protein (Rybp) In Glioblastoma Multiforme, Ronald W. Bucher

Graduate Theses

Glioblastoma multiforme (GBM) is an aggressive form of brain cancer that has horrendous survival outcomes with the use of current therapies. Further study into its molecular mechanisms will inform development of new, more effective treatments. The Polycomb protein RING1- and YY1- Binding Protein (RYBP) has emerged as an important gene in multiple cancers. In complex with other Polycomb proteins, RYBP acts to repress regions of chromatin, though it also performs other functions independent of these complexes. RYBP has a tumor suppressive role in various cancers, but may act as an oncogene in others, demonstrating its context-specific effects. The role of …

Studying The Phosphorylation Of Isocitrate Dehydrogenase In Humans, Hannah Smith

Chemistry & Biochemistry Undergraduate Honors Theses

Isocitrate dehydrogenase is an important enzyme in the citric acid cycle where it catalyzes the oxidative decarboxylation of isocitrate to alpha-ketoglutarate. While there are three isoforms of isocitrate dehydrogenase (IDH1, IDH2, and IDH3), this research will focus on IDH1. The phosphorylation of isocitrate dehydrogenase is a process that has been linked to the formation of both luminal-like and basal-like breast cancer. Despite these correlations, the mechanisms that cause breast cancer development are unknown. To examine this, an enzyme activity assay for each phosphorylation variant and crystallization were conducted. The results of these indicate that phosphorylation at each site (IDH1-T77, IDH1-S188, …

Uncovering Molecular Targets To Overcome Immunosuppression In Non-Small Cell Lung Cancer With Acquired Tki Resistance, Sonia A. Patel

Dissertations & Theses (Open Access)

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related deaths worldwide. Targeted therapeutic agents, such as epidermal-like growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) or monoclonal antibodies targeting vascular endothelial growth factor (VEGF/R), can effectively inhibit upregulated signaling pathways driving tumorigenesis in NSCLC and many other cancers. Unfortunately, however, resistance to such targeted therapies inevitably arise in most patients and can occur through a variety of resistance mechanisms including genomic alterations and upregulation of bypass pathways. Additionally, patients who have acquired resistance to these targeted agents typically have tumors characterized by an immunosuppressive tumor microenvironment and thus …

Kir-Based Inhibitory Cars Overcome Car-Nk Cell Trogocytosis-Mediated Fratricide And Tumor Escape, Ye Nmn Li

Dissertations & Theses (Open Access)

Trogocytosis is an active process that transfers surface material from targeted to effector cells. Using multiple in vivo tumor models and clinical data, we report that chimeric antigen receptor (CAR) activation in natural killer (NK) cells promoted the transfer of the CAR-cognate-antigen from tumor to NK cells, resulting in (1) lower tumor antigen density, thus impairing the ability of CAR-NK cells to engage with their targets, (2) induced self-recognition and continuous CAR-mediated engagement, resulting in fratricide of trogocytic antigen expressing NK cells (NK^TROG+) and NK cell hyporesponsiveness. This phenomenon could be offset by a dual-CAR system incorporating both …

Y Chromosome Gene Kdm5d Epigenetically Drives Sex Differences In Colorectal Cancer, Jiexi Li

Dissertations & Theses (Open Access)

Sex exerts a profound impact on cancer incidence, spectrum and outcomes, yet the molecular genetic bases of such sex differences are ill-defined and presumptively ascribed to X-chromosome genes and sex hormones. Such sex differences are particularly prominent in colorectal cancer (CRC) where men experience higher metastases and mortality. A murine CRC model, engineered with an inducible transgene encoding oncogenic mutant KRAS^G12D and conditional null alleles of Apc and Trp53 tumor suppressors (designated iKAP), revealed higher metastases and worse outcomes specifically in males with oncogenic mutant KRAS (KRAS*) CRC. Integrated cross-species molecular and transcriptomic analyses identified Y-chromosome gene histone demethylase …

Preclinical Evaluation Of Immunomodulatory Effects Of Aurora Kinase Inhibition In Human Papillomavirus Positive Cancers, Pragya Sinha

Dissertations & Theses (Open Access)

Human papillomavirus (HPV) is the causative agent of cervical cancer and some cancers of the penis, vulva, vagina, anus, and oropharynx. Current therapies for these cancers include a combination of surgery, radiotherapy, and chemotherapy that often results in permanent, life altering adverse effects. Immunotherapy is partially effective, but with significant recurrence and lower long-term survival. Importantly, there are no few biomarker-selective targeted therapies for these cancers. To address this unmet need, our collaborators conducted a large-scale drug screen and identified Aurora Kinase (AK) inhibitors as a unique class of reagents to induce selective apoptosis in HPV+, but not HPV- human …

Investigation Of The Role Of Dax-1 In The Hpa Axis In Human Adrenal Cells, Katerina N. Fargas

Undergraduate Honors Theses

DAX-1 is a nuclear hormone orphan receptor that plays a key role in the development of reproductive tissues and steroid hormone production. The hypothalamic-pituitary-adrenal axis is the pathway for steroid hormone production, primarily glucocorticoids, mineralocorticoids, and adrenal androgens, in the human body. The mechanisms of DAX-1 in hormone production in the adrenal cortex of the HPA axis are not completely understood and, therefore, were the focus of this honors thesis research project. Due to the high level of DAX-1 expression, SW13 adrenal carcinoma cells were conducted for these experiments. We investigated whether glucocorticoids, specifically the synthetic glucocorticoid dexamethasone, had any …

P53 Dimers Elicit Unique Tumor Suppressive Activities Through An Altered Metabolic Program, Jovanka Gencel-Augusto

Dissertations & Theses (Open Access)

p53 is the most frequently mutated tumor suppressor in human cancer. As a tetrameric transcription factor, mutation of the p53 Tetramerization Domain (TD) is a mechanism by which cancers abrogate wild-type (WT) p53 function. p53 TD mutations result in a protein that preferentially forms monomers or dimers. These are also normal p53 states under basal cellular conditions. Although it is accepted that tetrameric p53 is required for full tumor suppressive activities, the physiological relevance of monomeric and dimeric states of p53 is not well understood. We have established in vivo models for monomeric and dimeric p53 which model Li-Fraumeni Syndrome …

Functional Analysis Of Daxx In Tumorigenesis Of Pancreatic Neuroendocrine Tumors And Embryonic Development, Chang Sun

Dissertations & Theses (Open Access)

Death domain-associated protein 6 (Daxx) is a histone chaperone specific to Histone 3.3 (H3.3). DAXX interacts with ATRX forming a chromatin remodeling complex, which deposits H3.3 into telomeric and pericentric region of the genome. The importance of Daxx was manifested in embryonic development. The loss of Daxx leads to early lethality in mouse embryos around E6.5. Moreover, sequencing studies have revealed the importance of DAXX in human tumors. Mutually exclusive mutations in DAXX and ATRX occur in about 30% of pancreatic neuroendocrine tumors (PanNETs). Although lots of progress has been made in studying functions of DAXX, we still do not …

Hypoxia Activated Prodrug And Anti-Angiogenic Therapy Cooperate To Treat Pancreatic Cancer But Elicit Immune Suppressive G-Mdsc Infiltration, Arthur Liu

Dissertations & Theses (Open Access)

We previously showed that the hypoxia-activated prodrug TH-302 (Evofosfamide) reduces intratumoral hypoxia through a tissue remodeling process, initiates tumor vasculature reorganization, and sensitizes aggressive, spontaneous murine models of prostate cancer to immune checkpoint blockade (ICB). In a clinical trial testing the combination of TH-302 with cytotoxic T-lymphocyte-associated protein (CTLA-4) blockade (NCT03098160) a subset of metastatic, ICB refractory patients showed prolonged progression free survival. While these studies highlight hypoxia as therapeutically tractable, we lack a complete understanding of the contribution of the tumor vasculature to hypoxia reduction therapy, as well as the downstream consequences of hypoxia reduction on the cellular composition …

Regulation And Function Of Zeb1 Acetylation In Lung Adenocarcinoma Progression And Metastasis, Mabel Perez-Oquendo

Dissertations & Theses (Open Access)

Lung cancer metastasis is leading the causes of cancer-related mortality in the United States and worldwide. Epithelial-to-mesenchymal transition (EMT) is a model for metastasis that results in loss of specialized epithelial cell contacts and acquisition of mesenchymal invasive capacity. Zinc finger E-box-binding homeobox 1 (ZEB1) recognizes and binds to E-boxes of epithelial gene promoters to repress its transcription. ZEB1 has inconsistent molecular weights, which have been attributed to post-translational modifications (PTMs). In the presented dissertation, I specifically addressed the gap in the molecular mechanisms by which PTMs of ZEB1 regulate its ability to induce EMT and how its activity might …

A Dna-Peptide Crosslink (Dpc) Increases Mutagenicity In Sos-Induced Escherichia Coli, Alessandra Bassani

Honors Scholar Theses

Bacteria, such as Escherichia coli, have an inducible system in response to DNA damage termed the SOS response. This system is activated when the replicative DNA polymerase (Pol) III encounters a lesion, uncouples from DNA helicase, and single-stranded DNA (ssDNA) accumulates at the replication fork. In this study, we investigated DNA-peptide crosslink (DpC), a common lesion that results from cross-linking of proteins or peptides, UV irradiation, and alkylating agents. To increase survival following formation of a lesion, the SOS response can utilize homologous recombination, translesion synthesis (TLS), or excision repair. With TLS, the levels of DNA Pol II, IV, …

Investigating The Role Of Spatial Compartmentalization And Genomic Translocations In Metastatic Cancer: A Multi-Omic Analysis, Joshua Harris Garretson

Chancellor’s Honors Program Projects

No abstract provided.

Unique Transcriptional Profiles Underlie Osteosarcomagenesis Driven By Different P53 Mutants, Dhruv Chachad

Dissertations & Theses (Open Access)

Missense mutations in the DNA binding domain of the Trp53 gene are characterized as structural (p53R172H) or contact (p53R245W) mutations based on their effect on the conformation of the protein. These mutations show gain-of-function activities such as increased metastatic incidence as compared to p53 loss, often mediated by their interaction with a repertoire of transcription factors. These interactions are largely context specific. In order to understand the mechanisms by which these mutations drive osteosarcoma progression, we created a mouse model, wherein either the p53 structural mutant p53R172H, or the contact mutant, p53R245W, are expressed specifically in …

Computational Modeling Of The Fanconi Anemia Gene Network And Its Connection To Cancer, Alyssa Warren-Belford

Biological Sciences Undergraduate Honors Theses

Fanconi anemia (FA) is a rare genetic condition in which the cell’s DNA repair machinery is dysregulated, significantly increasing the chances of tumorigenesis. Further research is being done in order to improve patient outcomes and incidences of cancer. Our group created a computational model of the FA DNA repair gene network, which removes interstrand crosslinks found in damaged DNA and repairs it so DNA synthesis can continue. Computer simulations show the number of DNA damage indicators decreased as the pathway continued. This was expected as the FA pathway repairs DNA damage. The goal of this project was to provide further …

Investigating Three Novel Porphyrins For The Possible Treatment For Lung Cancer Using Red And White Light, Emmy Hipps

Scholars Day Conference

Photodynamic therapy (PDT) is a treatment method for various illnesses including cancer that uses a special drug, called a photosensitizer (PS). When a patient is injected with a PS, over time the PS is absorbed by the cancerous tumor. Light is then applied to area for treatment. The light then causes the drug to be activated, and singlet oxygen is produced that kills the cells. The PS in partnership with light causes cancer cells to undergo apoptosis. This research focuses on testing three novel water-soluble porphyrins, ZnTPPEA, H2TPP – TRIS, and H2TPPADIPA, as potential photosensitizing agents. All three novel photosensitizing …

Apoptosis Induction In Jurkat T-Lymphocytes By Proton Pump Inhibitors (Ppis), Shreya Murali, Randall Reif

Student Research Submissions

Apoptosis, commonly known as programmed cell death, constantly occurs in humans. As a cancer cell increases in acidity, apoptosis is induced. In healthy cells, proton pump proteins allow for H⁺ ions to permeate cellular membranes, regulating pH. However, proton pump inhibitors (PPIs), such as omeprazole, prevent proton movement. In previous studies, omeprazole induced cell death in Jurkat T lymphocytes; however, there was no confirmation of whether the cells died through apoptosis, or through necrosis, where the cell bursts. By using Annexin-V staining, the effects of omeprazole, dexlansoprazole, and esomeprazole on apoptosis induction can be measured. Cell death was observed …

Effect Of Tetracycline Derivatives On Metastasis In A Murine Mammary Tumor Model, Anna King, John Pryor, Serratt Nong

Liberty University Research Week

Undergraduate

Basic

Transcriptional Silencing Of Cdk18 And Its Role In Lung Carcinogenesis Of Brg1-Mutant Lung Cancers, Loryn M. Phillips

Biology ETDs

BRG1 is mutated in 10% of lung cancers, making this mutation clinically relevant. The downstream effects of BRG1 included significantly affecting the cell cycle control and chromosomal replication pathway. CDK18, a cyclin-dependent kinase, was determined to be the gene with significantly decreased expression (p

Utilizing Mass Spectrometry Imaging To Correlate N-Glycosylation Of Hepatocellular Carcinoma With Tumor Subtypes For Biomarker Discovery, Andrew Delacourt

MUSC Theses and Dissertations

Hepatocellular carcinoma (HCC) is a leading cause of cancer deaths globally and is a growing clinical problem with poor survival outcomes beyond early-stage disease. Surveillance for HCC has primarily relied on ultrasound and serum α-fetoprotein (AFP), but combined they only have a sensitivity of 63% for early-stage HCC tumors, suggesting a need for improved diagnostic strategies. Alterations to N-glycan expression are relevant to the progression of cancer, and there a multitude of N-glycan-based cancer biomarkers that have been identified with sensitivity for various cancer types including HCC. Spatial HCC tissue profiling of N-linked glycosylation by matrix-assisted laser desorption ionization imaging …