Medicine and Health Sciences Commons^™

Nuclear-Targeted Gold Nanoparticles Enhance The Effects Of Radiation Therapy With And Without Liposomal Delivery, Maureen Aliru

Dissertations & Theses (Open Access)

Less that 10% of pancreatic cancer patients are eligible for curative resection, and clinical trials evaluating chemoradiation in locally advanced patients with unresectable disease have been largely disappointing. New and creative therapeutic approaches are needed to address the unment need for treatment options. The objective of this thesis is to advance radiosensitization of treatment-resistant densely desmoplastic pancreatic cancer using nanoparticles to surmount biological barriers to effective particle distribution for DNA-targeting.

Clinical translation of radiosensitizing nanoparticles has stalled owing to technical challenges. Current strategies to use AuNPs for radiosensitization require large quantities of gold, kilovoltage x-rays, immediate irradiation after intravenous administration, …

Investigation Of The Functional Impact Of Anti-Pd-1 On Tumor-Infiltrating Lymphocytes (Til) And Mapping Of Tumor Genomic Features Relevant For Response To Til Therapy, Caitlin Creasy

Dissertations & Theses (Open Access)

With the growing use of both cellular and antibody-based immunotherapies, it has become more important to uncover biomarkers to predict patient response to therapy and ideally aid in patient selection for specific therapeutics, thereby enhancing treatment outcome. At MD Anderson, we have a 43% response rate to therapy when treating metastatic melanoma patients with adoptive cell therapy (ACT) of tumor-infiltrating lymphocytes (TIL), but it is unknown what makes the other 57% of patients not respond to therapy. It is further unknown how particularly early doses of checkpoint inhibitors, like anti-PD-1, attribute to TIL functionality, adding another confounding factor in determining …

Great Expectations: Phosph(On)Ate Prodrugs In Drug Design—Opportunities And Limitations, Victoria Yan

Dissertations & Theses (Open Access)

Phosphate and phosphonates are chemical moieties with historical precedence in anticancer and antiviral nucleotide analogues. Synchronous to modern efforts identifying novel therapeutic targets in cancer, such chemical moieties are being investigated in the design of novel inhibitors with antineoplastic potential. A central challenge to the delivery of phosph(on)ate-containing drugs is their anionic character at physiological pH, which portends poor membrane permeability. This limitation has been successfully overcome through the use of prodrugs. When attached to the phosph(on)ate moiety, prodrugs mask the negative charge and easily enable cell permeability. Upon cellular entry, the promoieties are enzymatically or environmentally cleaved to unveil …

Hyperpolarized Carbon-13 Magnetic Resonance Measurements Of Tissue Perfusion And Metabolism, Keith Michel

Dissertations & Theses (Open Access)

Hyperpolarized Magnetic Resonance Imaging (HP MRI) is an emerging modality that enables non-invasive interrogation of cells and tissues with unprecedented biochemical detail. This technology provides rapid imaging measurements of the activity of a small quantity of molecules with a strongly polarized nuclear magnetic moment. This polarization is created in a polarizer separate from the imaging magnet, and decays continuously towards a non-detectable thermal equilibrium once the imaging agent is removed from the polarizer and administered by intravenous injection. Specialized imaging strategies are therefore needed to extract as much information as possible from the HP signal during its limited lifetime.

In …

Reversal Of Neurodegeneration By Engineered Monocytes In Alzheimer’S Disease, Chao-Hsien Chen

Dissertations & Theses (Open Access)

The health challenges posed by Alzheimer’s disease (AD) continue to grow as societies age worldwide. Accumulation of Tau-associated pathology correlates with clinical cognitive deterioration in AD. Resident myeloid cells within the central nervous system (CNS) have a limited capacity to uptake and degrade Tau; however, the resulting secretion of proinflammatory cytokines only acts to accelerate neurodegeneration. Therapeutic antibodies can reduce the neurotoxic oligomeric form of Tau (o-Tau), but in doing so they also aggravate inflammation. Attenuating mutation of the antibody Fc region can silence inflammation but also eliminates its capacity to mediate o-Tau clearance by CNS myeloid cells. Thus, there …

Directed Evolution Of Macrocyclic Peptides For Inhibition Of Autophagy, Joshua Gray

Dissertations & Theses (Open Access)

In recent decades it has become increasingly clear that induction of autophagy plays an important role in the development of treatment resistance and dormancy in many cancer types. Chloroquine (CQ) and hydroxychloroquine (HCQ), two autophagy inhibitors in clinical trials, suffer from poor pharmacokinetics and high toxicity at therapeutic dosages. This has prompted intense interest in the development of targeted autophagy inhibitors to re-sensitize disease to treatment with minimal impact on normal tissue. We utilized Scanning Unnatural Protease Resistant (SUPR) mRNA display to develop macrocyclic peptides targeting the autophagy protein LC3. The resulting peptides bound LC3A and LC3B—two essential components of …

Investigating The Metabolic Progression Of Glioblastoma With Hyperpolarized Magnetic Resonance, Travis Salzillo

Dissertations & Theses (Open Access)

Rapid diagnosis and therapeutic monitoring of aggressive diseases such as glioblastoma (GBM) can improve patient survival by providing physicians the time to optimally deliver treatment. This includes early in development, while the tumor is still manageable, or following initial therapy, when alternative treatments should be considered. The main goal of this project was to determine whether metabolic imaging with hyperpolarized magnetic resonance spectroscopy (MRS) could detect changes in tumor progression more rapidly than conventional anatomic magnetic resonance imaging (MRI) in patient-derived GBM murine models. To comprehensively capture the dynamic nature of cancer metabolism, in vivo pyruvate-to-lactate conversion with hyperpolarized MRI, …

Alternative Polyadenylation Modulates Expression Of Pro-Fibrotic Proteins And Contributes To Lung Fibrosis, Junsuk Ko

Dissertations & Theses (Open Access)

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease which affects about 5 to 8 million individuals in the world. Despite the high prevalence, there is currently no cure for IPF, and the cause of this disease is still unclear. Our laboratory and collaborators have shown that nudix hydrolase 21 (NUDT21, which is also known as cleavage factor 25, CFIm25) is a key regulator of alternative polyadenylation (APA). NUDT21 depletion causes 3’UTR shortening via APA leading to enhanced mRNA stability and protein translation. This NUDT21 reduction promotes tumor growth in glioblastoma by enhancing expression of oncogenes. Cancer and IPF share …

Genetic Counselors' Experiences With And Approaches To Discordant Genotypic And Phenotypic Sex Detected Via Non-Invasive Prenatal Testing, Emily Stiglich

Dissertations & Theses (Open Access)

As the use of non-invasive prenatal testing becomes more ubiquitous during pregnancy, genetic counselors (GCs) will see clients more frequently for discordant sex identification via non-invasive prenatal testing (NIPT-DSI). Thus, it is imperative to investigate what GCs consider important when counseling about NIPT-DSI and assess how GCs perceive their role in such cases. Prenatal and pediatric GCs were surveyed regarding previous experiences of NIPT-DSI, comfort levels of topics relating to NIPT-DSI, and perceived importance of potential discussion topics in a counseling session (n = 108). The survey consisted of two vignettes, presenting cases of NIPT-DSI identified prenatally in one …

Preclinical Studies Of A Novel Idh1 Inhibitor In Acute Myeloid Leukemia (Aml), Vivian Salama

Dissertations & Theses (Open Access)

LY3410738, a novel covalent Isocitrate Dehydrogenase 1 (IDH1) inhibitor in Acute Myeloid Leukemia, it is more effective than Ivosidenib (AG120) and has a potent anti-leukemic effect against IDH1 mutant acute myeloid leukemia in combination with Venetoclax (ABT-199).

Acute myeloid Leukemia (AML) is an aggressive neoplastic blood disorder characterized by proliferation of poorly differentiated cells of myeloid lineage. IDH1 is a cytoplasmic enzyme that catalyze the oxidative decarboxylation of isocitrate to α-ketoglutarate (α-KG) in the citric acid cycle. Somatic gain-of-function mutations in IDH1 occur in ~10% of the newly diagnosed AML patients. The neo-enzymatic activity of mutant IDH1 results in accumulation …

Development Of Fully Balanced Ssfp And Computer Vision Applications For Mri-Assisted Radiosurgery (Mars), Jeremiah Sanders

Dissertations & Theses (Open Access)

Prostate cancer is the second most common cancer in men and the second-leading cause of cancer death in men. Brachytherapy is a highly effective treatment option for prostate cancer, and is the most cost-effective initial treatment among all other therapeutic options for low to intermediate risk patients of prostate cancer. In low-dose-rate (LDR) brachytherapy, verifying the location of the radioactive seeds within the prostate and in relation to critical normal structures after seed implantation is essential to ensuring positive treatment outcomes.

One current gap in knowledge is how to simultaneously image the prostate, surrounding anatomy, and radioactive seeds within the …

Genetic Counselors' Approaches To Direct-To-Consumer Genetic Testing For Hereditary Breast Cancer, Sarah Burke

Dissertations & Theses (Open Access)

Given the increasing availability of health-related direct-to-consumer genetic testing (DTC-GT) and third-party interpretation (TPI) services, it is likely that genetic counselors (GCs) will continue to encounter consumers that require follow-up counseling for their results. The National Comprehensive Cancer Network recommends clinical-grade genetic testing to confirm commercial results; however, the type of testing that GCs select remains uncharacterized. Therefore, we aimed to describe the specific recommendations that cancer GCs make for confirmatory genetic testing in probands who have already obtained DTC-GT results or TPI data that reported a BRCA1/2 pathogenic variant. We recruited 80 GCs specializing in hereditary cancer and administered …

Investigating Medical Examiners' Practices: Genetic Evaluation For Fatal Acute Aortic Dissection, Bradley Power

Dissertations & Theses (Open Access)

Acute thoracic aortic dissection (TAD) is a life-threatening event with a hereditary component. Currently, pathogenic variants in 11 genes associated with aortic aneurysm and dissection predispose to a heritable form of disease thereby conferring an increased risk for TAD. Genetic testing plays a pivotal role not only in diagnosis, but also in risk stratification for relatives and medical management to prevent premature death from dissection. Due to its high fatality rate, medical examiners and coroners (ME/Cs) may be the first to identify TAD cases and initiate genetic testing for the decedent and at-risk relatives. ME/Cs were surveyed using three clinical …

Molecular Mechanisms Of Antimicrobial Resistance In Multi-Drug Resistant Enterococci, Ayesha Khan

Dissertations & Theses (Open Access)

Antibiotic resistance is a major global public health threat. Enterococci are recalcitrant, nosocomial pathogens that can be intrinsically resistant to valuable antibiotics, like beta-lactams, or evolve resistance to all existing antimicrobials. The LiaFSR system regulates resistance to cell membrane (CM) stressors like daptomycin (DAP), a front-line drug for multi-drug resistant infections. DAP resistance (DAP-R) in E. faecalis is mediated by CM phospholipid alterations. Emergence of DAP-R often leads to b-lactam resensitization, a phenomenon called the seesaw effect. The molecular mechanism of DAP-R and the seesaw effect are unknown. Here we show that LiaX is a surface exposed protein whose C-terminal …

Frequency Of Copy Number Variants Involving The Sex Chromosomes In A Clinical Setting, Autumn Vara

Dissertations & Theses (Open Access)

Copy number variants (CNVs) are a common finding in the clinical setting and contribute to both genetic variation as well as disease. Recently, studies have described the accumulation of multiple CNVs as a disease modifying mechanism. While it has been characterized how additional CNVs may play a role in phenotype, in which ways and to what extent sex chromosomes are involved has not been fully described. We performed a secondary data analysis using the DECIPHER database on 2,273 de-identified individuals with 2 CNVs. CNVs were designated primary and secondary based on our criteria and characteristics of both CNV groups were …