Cancer Biology Commons^™

Development Of Combination Therapy Strategies To Treat Cancer Using Dihydroorotate Dehydrogenase Inhibitors, Nicholas Mullen

Theses & Dissertations

Cancer cells require supraphysiologic levels of nucleotide triphosphates to fuel their malignant behaviors, including uncontrolled proliferation, immune evasion, metastasis, and therapy resistance. This requirement is met by hyperactive flux through the de novo pyrimidine and de novo purine pathways. Dihydroorotate dehydrogenase (DHODH) is an essential enzyme in the de novo pyrimidine pathway that can be targeted by FDA approved and experimental drug compounds. A robust body of preclinical evidence, encompassing hundreds of independent studies over several decades, demonstrates impressive activity of DHODH inhibitors in animal models of cancer. Paradoxically, however, all clinical trials to date have failed to demonstrate efficacy …

Targeting The Cxcr1/2 Axis In Pancreatic Ductal Adenocarcinoma, Caitlin Molczyk

Theses & Dissertations

Pancreatic ductal adenocarcinoma (PDAC) is notoriously challenging to diagnose and treat. This tumor has an aggressive phenotype and benign clinical features until severe disease dissemination, which makes it too late to eradicate. Although it is only the 10th most common cancer in the United States, it is the fourth leading cause of cancer-related deaths. The treatment options are complicated further due to tumor heterogeneity, meaning not all tumor cells are in the same state phenotypically or epigenetically. They also express cytokines, chemokines, and receptors differently. Here we explore the usage of CXCR1 and CXCR2 and their ligands in PDAC tumor …

Parkin Ubiquitination Of Kindlin-2 Enables Mitochondria-Associated Metastasis Suppression, Minjeong Yeon, Irene Bertolini, Ekta Agarwal, Jagadish C Ghosh, Hsin-Yao Tang, David W. Speicher, Frederick Keeney, Khalid Sossey-Alaoui, Elzbieta Pluskota, Katarzyna Bialkowska, Edward F. Plow, Lucia R. Languino, Emmanuel Skordalakes, M Cecilia Caino, Dario C. Altieri

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Mitochondria are signaling organelles implicated in cancer, but the mechanisms are elusive. Here, we show that Parkin, an E3 ubiquitination (Ub) ligase altered in Parkinson's disease, forms a complex with the regulator of cell motility, Kindlin-2 (K2), at mitochondria of tumor cells. In turn, Parkin ubiquitinates Lys581 and Lys582 using Lys48 linkages, resulting in proteasomal degradation of K2 and shortened half-life from ∼5 h to ∼1.5 h. Loss of K2 inhibits focal adhesion turnover and β1 integrin activation, impairs membrane lamellipodia size and frequency, and inhibits mitochondrial dynamics, altogether suppressing tumor cell-extracellular matrix interactions, migration, and invasion. Conversely, Parkin does …

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, …

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 …

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, …

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 …

Elucidating Mechanisms Involved In Host Microbial-Tumor Interactions, Vidhi Chandra

Dissertations and Theses (Open Access)

Cancer is a rising cause of mortality worldwide. Microbiota is the collection of micro-organisms that live inside our bodies and can impact the host health and disease by interacting with the immune and metabolic systems. The relationship between the microbiota and cancer is complex. Gut and intratumoral microbiota can affect cancer development and progression by influencing patient outcomes and therapy responsiveness in several cancer types. Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer surrounded by a highly immuno-suppressive tumor microenvironment (TME) which limits efficacy of most available therapies. The tumoral niche provides a privileged microenvironment for microbial colonization that can …

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

Dissertations and 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 …

Oncolytic Virus Immunotherapy: Development And Potential For Cancer Treatment, Olivia Guinness

Honors Scholar Theses

The American Cancer Society estimates that in 2023, 1,958,310 new cancer cases and 609,820 cancer deaths will occur in the United States [16]. A promising therapeutic option that has been supported by recent clinical trials is the use of oncolytic viruses to treat malignant tumors. The mechanism of action of existing treatments, such as chemotherapy, radiotherapy, and surgery, differs from that of oncolytic virus therapy because oncolytic viruses are able to affect cancer cells with specificity, minimizing side effects. When infecting a normal, non-cancerous cell, oncolytic viruses do not replicate, leaving healthy cells unaffected. In tumor cells, oncolytic viruses will …

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

Dissertations and 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 …

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

Dissertations and 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 …

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

Dissertations and 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 and 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 and 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 …

Regulation Of De Novo And Maintenance Dna Methylation By Dnmt3a And Dnmt3b, Yang Zeng

Dissertations and Theses (Open Access)

DNA methylation (5-methylcytosine, 5mC) is essential for the regulation of gene expression and integrity of the mammalian genome. It occurs predominantly in the context of CpG dinucleotides to form a symmetrical pattern on both DNA strands, which allows DNA methylation patterns to be semi-conservatively maintained during DNA replication. There are two classes of DNA methyltransferases (DNMTs): DNMT3A and DNMT3B function primarily as de novo methyltransferases that establish DNA methylation patterns, whereas DNMT1 is the major enzyme responsible for maintaining DNA methylation patterns by converting hemi-methylated CpGs to fully methylated CpGs during DNA replication. Two accessory factors also play critical regulatory …

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

Dissertations and 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 and 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 …

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

Dissertations and 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 …

A Comprehensive Analysis Of Different Types Of Databases Reveals That Cdh1 Mrna And E-Cadherin Protein Are Not Downregulated In Most Carcinoma Tissues And Carcinoma Cell Lines, Brihget Sicairos, Shorna Alam, Yuchun Du

Biological Sciences Faculty Publications and Presentations

Background

The CDH1 gene codes for the epithelial-cadherin (E-cad) protein, which is embedded in the plasma membrane of epithelial cells to form adherens junctions. E-cad is known to be essential for maintaining the integrity of epithelial tissues, and the loss of E-cad has been widely considered a hallmark of metastatic cancers enabling carcinoma cells to acquire the ability to migrate and invade nearby tissues. However, this conclusion has come under scrutiny.

Methods

To assess how CDH1 and E-cad expression changes during cancer progression, we analyzed multiple large transcriptomics, proteomics, and immunohistochemistry datasets on clinical cancer samples and cancer cell lines …

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

Departmental Honors & Graduate Capstone Projects

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 < 0.0001) in the cell cycle control and chromosomal replication pathway. CDK18 is active during the S-phase of the cell cycle and required for genomic stability. Studies were conducted to determine the epigenetic mechanisms that contributed to the repression of CDK18. Histone methylation contributes to the repression of CDK18, and histone deacetylation globally regulates expression of CDK18, while cytosine methylation was found to not contribute to CDK18 expression. Studies were performed to elucidate CDK18 functional role lung carcinogenesis and the genome-wide impact of CDK18 repression. Repression of CDK18 affects cell migration, proliferation, cell-cell signaling, and anchorage-independent growth that contribute to cancer initiation and progression.

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 …

Potentiation Of The Immune Checkpoint Blockade Response By Metabolic Modulation Is Predictable Using Molecular Imaging, Renee L. Chin

Dissertations and Theses (Open Access)

Unregulated cell division is a hallmark of cancer. The high metabolic needs of the tumor cells result in nutrient depletion and produce a hostile tumor microenvironment (TME) for antitumor immune cells, protecting the tumor from immune cell-mediated control and immunotherapy. Two of these environmental factors, acidosis and hypoxia, are commonly found in solid cancers. In my thesis, I posited that modulation of tumor acidosis and hypoxia can serve as biomarkers by indicating immunogenicity and tumor sensitivity to immune checkpoint blockade (ICB) as monitored using molecular imaging. Esomeprazole was found to promote tumor immunogenicity and induce tumor control when used to …

Mirna-489 Induces Immunogenic Cell Death In Triple Negative Breast Cancer Cells, Ryan P. Titus

Senior Theses

It has been well established that microRNAs (miRNAs) play an important role in the regulation of gene expression and consequently promoting or downregulating molecular pathways. When dysregulated, miRNAs have been found to serve as important biomarkers for cancer diagnosis and influence tumor initiation and progression. It has been previously established that miRNA-489 is a tumor suppressor microRNA, and it directly targets cell proliferative pathways like the HER2-SHP2-MAPK pathway. In this study, we focus on the role of miRNA-489, in the induction of immunogenic cell death (ICD) in triple-negative breast cancer cell lines. We first examined the effects of miRNA-489 on …

Cell-Typing And Interaction Analysis Of The Immune Compartment Of The Tumor Microenvironment Using High-Resolution Omics Modalities, Courtney Taylor Schiebout

Dartmouth College Ph.D Dissertations

Single-cell RNA-sequencing (scRNA-seq) has provided a new frontier for the investigation of complex tissues. One ideal candidate for the utilization of this method is the tumor microenvironment (TME). The TME is often host to a complex set of cell populations and behaviors that can be highly influential for cancer inhibition or progression. This is especially true of the immune compartment of the TME: the presence of certain types of immune cells in the TME and their expression profiles can significantly affect cancer prognosis in some cases. By providing individual cell-level gene expression data, scRNA-seq can be highly informative for characterizing …

Understanding The Implications Of Lineage Plasticity In Breast Cancer Evolution And Chemotherapy Response, Gadisti Aisha Mohamed

Dartmouth College Ph.D Dissertations

Intra-tumoral heterogeneity and the presence of a phenotypically diverse cell population within a single tumor represents a major hurdle in the understanding of tumor progression and dynamics, and complicates the effective diagnosis and management of this disease. One of the ways by which tumors gain intra-tumoral variation is through the acquisition of phenotypic or lineage plasticity, whereby tumor cells evolve away from the lineage of origin and gain altered profiles. These alterations may impart specific survival benefits to different subpopulations of cells, enabling them to proliferate faster, migrate away from the site of the primary tumor or evade drug-induced elimination, …

Crosstalk Between The Extracellular Matrix And The Cell- Cell Junction - Associated Rnai Machinery Regulates Colon Cancer Cell Behavior, Amanda Daulagala

MUSC Theses and Dissertations

Colon cancer is the third most common and second deadliest type of cancer. Colon cancer is broadly characterized by compromised epithelial integrity and by aberrant extracellular matrix (ECM) remodeling. However, a potential mechanistic connection between epithelial integrity and ECM remodeling that could be contributing to the disease progression, has not been explored yet. The Adherens Junction (AJ) is a cell-cell adhesion complex composed of cadherin and catenin family proteins and essential for establishing and maintaining epithelial tissue integrity. Our previous work revealed that PLEKHA7, an E-cadherin-p120 catenin partner, recruits the microprocessor and the RNA-induced silencing complex (RISC), key components of …