Biochemistry, Biophysics, and Structural Biology Commons^™

Functional Characterization Of Cancer-Associated Dna Polymerase Ε Variants, Stephanie R. Barbari

Theses & Dissertations

Replicative DNA polymerases ε (Polε) and δ (Polδ) achieve high fidelity DNA synthesis through a precise balance of polymerization and exonucleolytic proofreading. Errors that escape proofreading are corrected by DNA mismatch repair (MMR). Ultramutated human cancers with proficient MMR carry alterations in the exonuclease domain of Polε, which were initially predicted to abolish proofreading. However, functional studies in yeast of the most recurrent Polε-P286R variant suggested defects beyond a loss of exonuclease activity. Indeed, biochemical analysis of the yeast Polε-P286R analog revealed increased polymerization capacity in addition to decreased proofreading, which enables efficient mismatch extension and bypass of replication-blocking non-B …

In Vitro Investigation Of Tumor Selective Piperidones As Therapeutic Agents Against Leukemia Cancer Cells, Lisett Contreras

Open Access Theses & Dissertations

Cancer is a continuous global health issue. It is the second leading cause of death behind heart disease. Disparities across the emergence of cancer and resulting fatalities raise the importance of researching the disease. Treatments are available for certain types of cancers. However, these are typically accompanied by residual problems including side effects and the possibility for relapse. Some treatments attack all cells, leading to unwarranted side effects that make the possibility of living a comfortable life nearly impossible. Other treatments are specific to certain genetic alterations, making them only useful for a small percentage of patients. Not one treatment …

Differentiating The Mechanistic Role And Chemotherapeutic Potential Of Src And Podoplanin In Oncogenic Transformation, Edward P. Retzbach

Graduate School of Biomedical Sciences Theses and Dissertations

There were an estimated 20 million new cancer cases worldwide in 2020, resulting in nearly 1000 deaths per hour [1]. Oral cancer exemplifies the difficulties of treating cancer patients. The first line for oral cancer treatment is surgery and radiation that can lead to patient disfigurement and decreased quality of life in cancer survivors [2-4]. Though there have been many developments in chemotherapy in the last 30 years, the 50% mortality rate associated with oral cancer has not changed [4, 5]. Longitudinal studies that track survival rates in oral cancer patients demonstrate a 3-fold reduction in patient deaths when patients …

Converging Technologies: Targeting The Hallmarks Of Cancer Using Ultrasound And Microbubbles, Janith Wanigasekara, Andressa Maria Aguiar De Carvalho, Patrick J. Cullen, Brijesh Tiwari, James F. Curtin

Articles

Various complex biological effects occur when ultrasonic compression waves travel through biological material. The myriad of biological outcomes instigated by ultrasound are evident when viewed through the lens of the hallmarks of cancer. Herein, we summarise the therapeutic potential of ultrasound, enhanced by microbubbles, for the treatment of cancer.

Examination Of Methylation Status And Occupancy Of Dna Methylation Modifying Proteins On Regulatory Regions Of The Dax-1 Gene, Caroline P. Riedstra

Master's Theses

Epigenetic modifications influence gene expression and thereby play a pivotal role in development and disease. Misregulation and mutations in the DAX-1 gene, or Dosage-Sensitive Sex Reversal, Adrenal Hypoplasia Congenita, Critical Region on the X chromosome, gene 1, have been implicated in Adrenal Hypoplasia Congenita (AHC) and Dosage Sensitive Sex Reversal (DSS). The orphan nuclear hormone receptor DAX-1 is expressed predominantly in tissues such as the testes, ovaries, breast, adrenal cortex, and lung. Critically, DAX-1 may serve as an indicator of aberrant growth in these tissues. Here we hypothesize that DAX-1 is epigenetically regulated, specifically in cancer cells, thereby reducing its …

Unveiling Global Roles Of G-Quadruplexes And G4-22 In Human Genetics, Ruth Barros De Paula

Dissertations & Theses (Open Access)

G-quadruplexes are non-B DNA structures formed by four or more runs of repeated guanines that confer unique features to living organism’s genomes. These sequences are enriched in regulatory regions, such as promoters and 5’ UTRs, and have distinct regulatory roles in both health and disease states. Even though previous studies showed the impact of G4 in gene expression, none of them summarized the location-specific effect of G4. Also, there is no broad understanding about the most common G4 repeat in the human genome, named here as G4-22, and how it links to the evolution of mammals and their biology. In …

A Time-Course Characterization Of Muscle Function And Mitochondrial Markers During Colorectal Cancer-Induced Cachexia In Tumor-Bearing Male Mice, Ana Cabrera Ayuso

Graduate Theses and Dissertations

Cachexia is a multisystemic and multifactorial syndrome prevalent in cancer patients. It is clinically defined by involuntary loss of >5% weight in a six-month window, despite nutritional interventions. A negative energy balance characterizes cancer cachexia (CC), it is associated with weakness and fatigue in skeletal muscle. Impaired muscle function is associated with lower quality of life in cancer patients. Defects in mitochondrial function are strongly associated with muscle wasting. This study explored muscular contractile function and mitochondrial quality control (MQC) markers in soleus, gastrocnemius, and tibialis anterior (TA) muscles of C26-induced male tumor-bearing mice during a 25-day time course. It …

Evolution Of Targeted Therapy Resistance In Eml4-Alk Positive Non-Small Cell Lung Cancer, Robert Vander Velde

USF Tampa Graduate Theses and Dissertations

Targeted therapies have emerged as potent treatments that lead to the remission of many tumors. However, they rarely cure cancers in advanced, metastatic settings. This is due to the evolution of resistance, which in turn can be ascribed to the survival of small subpopulations of tolerant and/or resistant cells. Here we investigated the evolution of resistance to EML4-ALK inhibitors in non-small cell lung cancer (NSCLC) and demonstrated that resistance evolves gradually, from unique pre-treatment sub-populations, as multiple resistance mechanisms accumulate in a Darwinian fashion. Despite accumulating multiple changes, cells evolved, in parallel, toward similar inhibitor specific phenotypes. Evolving cells have …

Understanding The Role Of Ano1 In Oral Cancer, Mallary Forrest

UNLV Theses, Dissertations, Professional Papers, and Capstones

In 2008, the gene ANO1 was discovered to encode a calcium activated chloride channel. This gene is located on the 11q13 locus, a locus that is commonly amplified in many cancers including cancer of the head and neck. ANO1 is situated in close proximity to genes associated with growth and apoptosis. As rapid proliferation and lack of apoptosis are hallmark characteristics of cancer, growth factors and apoptosis mediators are expected to be altered in cancer. But what does a calcium activated chloride channel have to contribute to cancer’s pathogenesis? Is it an active gene in cancer progression or is it …

Analyzing The Effects Of E-Hook Peptides On Kinesin-1, Ashton Ward Murrah, Baylee Hope Howard

Honors Theses

Cancer is the second leading cause of death in the United States. Cancerous growth is a result of oncogenes, or mutated genes that increase the rate of cell division in an uncontrolled manner. Cell division, which consists of mitosis and cytokinesis phases, is dependent upon the active movement of kinesin motor proteins along microtubules to rearrange the cytoskeleton for equitable distribution of genetic material to daughter cells. As kinesins are vital to this process, if we could prevent kinesin from binding to the microtubules, cell division would cease.

The goal of this study is to develop a method to prevent …

The Effect Of Cadmium On Ovarian Adenocarcinoma Cell Lines: An Investigation Of The Possible Mechanism Of Action, Haley Todd

Undergraduate Theses

Cadmium, a heavy metal and carcinogen, is an environmental and workplace contaminate. As a known endocrine disruptor, it can mimic the proliferative effects of estrogen and is classified as a metalloestrogen. While the proliferative effect of estrogen on cancerous cell growth has been well established, the effects of cadmium have not been fully examined. To determine if cadmium stimulates growth in two human ovarian adenocarcinoma cell lines, OVCAR3 and SKOV3, cells were treated for 48 hours with varying concentrations of cadmium, 0.001 µM – 10 µM, and growth was measured using a cell proliferation assay. Both cell lines showed a …

Protocol For Rapid Assessment Of The Efficacy Of Novel Wnt Inhibitors Using Zebrafish Models, Meghan G. Haney, Mary Wimsett, Chunming Liu, Jessica S. Blackburn

Molecular and Cellular Biochemistry Faculty Publications

Dysregulation of Wnt signaling is a hallmark of many cancers, and the development of effective, non-toxic small-molecule Wnt inhibitors is desirable. Off-target toxicities of new compounds are typically tested in mouse models, which is both costly and time consuming. Here, we present a rapid and inexpensive protocol to determine the in vivo toxicity and efficacy of novel Wnt inhibitors in zebrafish using a combination of a fluorescence reporter assay as well as eye rescue and fin regeneration assays. These experiments are completed within 1 week to rapidly narrow drug candidates before moving to more expensive pre-clinical testing.

For complete details …

Biophysical Characterization Of The Par-4 Tumor Suppressor: Evidence Of Structure Outside The Coiled Coil Domain And Interactions With Platinum Chemotherapeutics, Andrea Megan Clark

Chemistry & Biochemistry Theses & Dissertations

Prostate apoptosis response-4 (Par-4) is an apoptosis-inducing tumor suppressor protein. Full-length Par-4 has previously been shown to be a predominantly intrinsically disordered protein (IDP) under neutral conditions, with significant regular secondary structure evident only within the C-terminal coiled coil domain. However, IDPs can gain ordered structure through the process of induced folding, which often occurs under non-neutral conditions. Previous work has shown that the Par-4 leucine zipper, which is a subset of the C-terminal coiled coil domain, is disordered under neutral conditions, but forms a dimeric coiled coil at acidic pH. Increase in ionic strength was also shown to increase …

Improvement In 14-3-3 Binding Site Prediction, Katherine K. Mccormack

ScholarsArchive Data

The 14-3-3 family of phospho-binding proteins regulate a variety of major cellular processes through interaction with a network of dynamic proteins. Deregulation of the 14-3-3 interaction network contributes to a variety of degenerative disorders and cancers. Our lab focuses on identifying novel 14-3-3 interactions and understanding how 14-3-3 binding regulates protein function. A major gap in this process is that identifying the phospho-site where 14-3-3 docks on a given protein is time- and resource-consuming. Prediction algorithms have been developed to predict canonical 14-3-3 binding sites, however, there are many non-canonical sites that existing software is unable to predict. To fill …

Use Of Small Molecule Fanconi Anemia Pathway Inhibitors As Sensitizing Agents To Laromustine., Sam W. Marchant

Honors Theses

Laromustine is an experimental chemotherapeutic sulfonyl hydrazine prodrug shown in clinical trials to be effective against acute myeloid leukemia. The mechanism of action of laromustine involves interstrand crosslinking, via chloroethylation, and enzyme inhibition, caused by carbamoylation. The work described herein aims to investigate whether inhibition of the replication-dependent interstrand crosslink repair Fanconi Anemia pathway further sensitizes cells to laromustine. By measuring metabolic activity immediately after drug exposure, we find laromustine to be equally as cytotoxic towards Fanconi Anemia deficient and wild type cells. However, through clonogenic assays we show Fanconi Anemia mutations sensitize cells to laromustine’s anti-proliferative effect. Furthermore, we …

Understanding The Epigenetic Role Of 8-Oxoguanine And Ogg1 In Non-Small Cell Lung Cancer, Kyrellos Ibrahim

CMC Senior Theses

Oxidative damage to the genome can form 8-oxoguanine (oxoG), a premutagenic lesion suggested to play an epigenetic role in the regulation of various cellular pathways. Alongside oxoG in this regulation is the 8-oxoguanine DNA glycosylase (OGG1), which primarily functions to repair oxoG damage via base excision repair, but is also implicated in recruiting NFκB and impacting gene expression associated with cancer growth. This proposal aims to build genome-wide maps of oxoG occupancy, and indirectly OGG1 localization, in healthy lung cells and in non-small cell lung cancer adenocarcinoma cells in order to identify regulatory regions in the genome at which oxoG …