Oncology Commons^™

The Tca Cycle As A Nexus Of Metabolic Vulnerabilities In Cancer, Sunada Khadka

Dissertations & Theses (Open Access)

Uncontrolled proliferation of cancer cells necessitates rewiring of metabolic pathways to meet biosynthetic and bioenergetic demands of proliferation and fortify redox homeostasis. An increasing body of literature suggests that mitochondrial metabolism (tricarboxylic acid cycle (TCA) and oxidative phosphorylation) is imperative for cancer cell growth and proliferation. The scope of the works presented in this dissertation is to explore the importance of mitochondrial metabolism, and primarily the TCA cycle—the anabolic factory of cancer cells and leverage it as a targetable vulnerability in cancer. Cancer cells consume anabolic nutrients that are used to generate biosynthetic precursors in the TCA cycle. Continuous efflux …

Breast Cancer Risk For Female Relatives Of Male Breast Cancer Patients With Negative Brca1/2 Testing, Emily Martin

Dissertations & Theses (Open Access)

Risk models exist to estimate a female’s lifetime risk of breast cancer in the absence of a hereditary predisposition to cancer, namely Hereditary Breast and Ovarian Cancer syndrome. These risk models consider various factors such as reproductive history and family history, but few models take a family history of male breast cancer into account. This study aims to evaluate if prevalence of breast cancer among female relatives is higher when there is a family history of male breast cancer in the context of uninformative BRCA1 and BRCA2 testing. This information may aid in the process of risk assessments for patients …

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, …

Oxidative Phosphorylation: A Critical Feature And Novel Therapeutic Target In Melanoma Brain Metastases, Grant Fischer

Dissertations & Theses (Open Access)

We recently showed via RNA-sequencing (RNA-seq) analysis of clinical samples that melanoma brain metastases (MBMs) have higher expression of oxidative phosphorylation (OXPHOS) genes (including PPARGC1A or PGC1α) than patient-matched extracranial metastases (ECMs). Thus, the central hypothesis of this dissertation is that OXPHOS plays a critical role in the pathogenesis of MBMs.

RNA-seq analysis identified increased expression of OXPHOS genes in intracranial (ICr) vs. subcutaneous (SQ) xenografts of 4 different human melanoma cell lines. Increased OXPHOS in the ICr xenografts was confirmed by direct metabolite analysis and [U-¹³C]-glucose tracing analysis. Together, these studies indicate that the brain TME …

Tracking Treatment Response And Resistance To Parp Inhibition (Talazoparib) In Hereditary Pancreatic Cancer., Jennifer Goldstein

Dissertations & Theses (Open Access)

polyADP ribose polymerase (PARP) inhibitors are a class of drugs that block the PARP enzymes, involved in the repair of singe-stranded DNA breaks through the base excision repair pathway. PARP inhibition leads to replication-associated double stranded DNA breaks, which are repaired by homologous recombination (HR). In tumors with HR defects (i.e. BRCA mutants), there is a shift to error-prone DNA repair and subsequent genomic instability and cell death.

In 2014, Olaparib became the first FDA-approved PARP inhibitor for the treatment of BRCA-mutant ovarian cancer. In the phase III POLO (Pancreas cancer OLaparib Ongoing) trial presented at the American Society …

Outcomes Of Genetic Testing In A Genitourinary Genetics Clinic, Annelise Pace

Dissertations & Theses (Open Access)

Several known hereditary cancer syndromes confer an increased risk for genitourinary (GU)related malignancies. Various guidelines indicate when to refer patients to genetic counseling for GU-related hereditary cancer syndromes but there is limited research on the clinical picture of these patients, including their cancerous and non-cancerous features, the genetic testing strategy for this population, and the probability of having a positive germline mutation if testing is performed. The purpose of this study is to determine the most common indications for ordering genetic testing in a GU Genetics Clinic and evaluate whether there is a relationship between the indication for genetic testing …

Dynamic Assessment Of Nk Cell Interactions With Pediatric Tumor Cells To Predict Response To Immunotherapy, Arianexys Aquino Lopez

Dissertations & Theses (Open Access)

Due to Natural Killer (NK) cells’ capacity to target tumor cells without prior sensitization, adoptive NK cell therapy represents a promising immunotherapy approach for pediatric cancer patients. Our laboratory has developed an NK cell expansion protocol that generates large quantities of NK cells for therapeutic infusion. Given that NK cells are heterogeneous, with variable receptor expression and potential to target tumor cells, the purpose of my study was to determine whether subpopulations of NK cells with enhanced anti-tumor potential could be identified for increased potency of the NK cell infusion product. In addition, we previously showed that our expanded NK …

Parp Inhibitor Upregulates Pd-L1 Expression And Enhances Cancer-Associated Immunosuppression, Shiping Jiao

Dissertations & Theses (Open Access)

With recent approvals for therapeutic antibodies that block CTLA4, PD-1 and PD-L1, immune checkpoints have emerged as new targets in cancer therapy. In addition, there is accumulating evidence highlighting the role of cancer-associated immunity in patient response to cytotoxic anticancer agents. Inhibitors of poly (ADP-ribose) polymerase (PARP) have shown substantial cytotoxic effects against tumors with defects in DNA damage responses. However, whether a crosstalk between PARP inhibition and immune checkpoints exists remains unclear. Here, it has been shown that PARP inhibitors (PARPis) upregulate PD-L1 expression in multiple cancer cell lines, human xenograft tumors, and syngeneic mouse tumors. Mechanistically, PARPi inactivates …

Repetitive, Pre-Anesthetic Fasting And Malnutrition In A Pediatric Oncology Population Undergoing Radiation Therapy, Laura P. Santibáñez

Dissertations & Theses (Open Access)

Background: Pediatric oncology patients often experience nutritional status changes, particularly malnutrition, which may adversely affect their outcomes. Although the consequences of malnutrition are elucidated, its causes remain unclear. A possible cause of malnutrition in pediatric oncology patients is repetitive, pre-anesthetic fasting prior to non-invasive procedures and treatments, such as anesthesia-assisted radiation therapy (AART). This exploratory study investigated the association between repetitive, pre-anesthetic fasting and non-fasting days and malnutrition in pediatric oncology patients receiving AART.

Procedure: A retrospective cohort of 138 pediatric oncology patients (£ 10 years of age) who received any type of radiation therapy (RT) with or without anesthesia …

Evaluating The Nccn Clinical Criteria For Hereditary Breast And Ovarian Cancer Syndrome Genetic Testing, Caiqian Wu

Dissertations & Theses (Open Access)

Hereditary Breast and Ovarian Cancer (HBOC) syndrome predisposes females with a BRCA1 or BRCA2 mutation to an up to 85% lifetime risk for breast cancer and an up to 40% lifetime risk for ovarian cancer. It is crucial for individuals with HBOC to be identified to allow for proper screening, management, and identification of at-risk family members in order to reduce mortality. The National Comprehensive Cancer Network (NCCN) has established clinical guidelines for when to recommend BRCA1/2 testing. A retrospective chart review of 1123 M.D. Anderson Cancer Center breast cancer patients was performed in order to evaluate the positive predictive …

Gene Set Analysis Of Post-Lactational Mammary Gland Involution Gene Signatures In Inflammatory And Triple Negative Breast Cancer, Arvind Bambhroliya

Dissertations & Theses (Open Access)

With each cycle of pregnancy and lactation, the mammary gland undergoes dramatic changes. Clarkson et al. (2004) and Stein et al. (2004) conducted a detailed analysis of these changes in the mouse mammary gland. Their results showed that tissue remodeling during post-lactational involution period mimics wound healing and tumorigenesis like pathological conditions. This indicates that post-lactational involution may create the microenvironment that initiates the development of precancerous mammary cells and promotes the progression of precancerous cells into cancer cells. Moreover, epidemiological studies have found that triple-negative (TN) breast cancer (BC) is associated with lower frequency and duration of breastfeeding compared …

Evaluation Of Current Clinical Criteria For Li-Fraumeni Syndrome In A Diverse Sample Of Tp53 Mutation Carriers, Emily A. Parham

Dissertations & Theses (Open Access)

Li-Fraumeni syndrome (LFS) is a hereditary cancer predisposition syndrome caused by heterozyogous germline mutations in the TP53 gene and characterized by an excess of early-onset cancers, high lifetime risk of cancer, and a wide range of tumor types. Recent studies suggesting a benefit in comprehensive screening protocols for both children and adults make the timely identification of individuals with LFS increasingly important.

A number of criteria have been proposed to identify patients with LFS. The National Comprehensive Cancer Network (NCCN) combines several in its Clinical Practice Guidelines for TP53 genetic testing. Prior studies have shown that the cumulative sensitivity of …

Characterization Of Differentiation And Prognostic Biomarkers On Cd8+ Tumor-Infiltrating Lymphocytes In Metastatic Melanoma, Richard C. Wu

Dissertations & Theses (Open Access)

CD8⁺ cytotoxic T lymphocytes (CTL) frequently infiltrate tumors, yet most melanoma patients fail to undergo tumor regression. We studied the differentiation of the CD8⁺ tumor-infiltrating lymphocytes (TIL) from 44 metastatic melanoma patients using known T-cell differentiation markers. We also compared CD8⁺ TIL against the T cells from matched melanoma patients’ peripheral blood. We discovered a novel subset of CD8⁺ TIL co-expressing early-differentiation markers, CD27, CD28, and a late/senescent CTL differentiation marker, CD57. This CD8⁺CD57⁺ TIL expressed a cytolytic enzyme, granzyme B (GB), yet did not express another cytolytic pore-forming molecule, perforin (Perf). In …

Taz As A Regulator Of Mesenchymal Transformation And Clinical Aggressiveness In Gliomas, Katrina Salazar

Dissertations & Theses (Open Access)

Glioblastoma multiforme (GBM) is an aggressive, high grade brain tumor. Microarray studies have shown a subset of GBMs with a mesenchymal gene signature. This subset is associated with poor clinical outcome and resistance to treatment. To establish the molecular drivers of this mesenchymal transition, we correlated transcription factor expression to the mesenchymal signature and identified transcriptional co-activator with PDZ-binding motif (TAZ) to be highly associated with the mesenchymal shift. High TAZ expression correlated with worse clinical outcome and higher grade. These data led to the hypothesis that TAZ is critical to the mesenchymal transition and aggressive clinical behavior seen in …

Bim Mediates Imatinib-Induced Apoptosis Of Gastrointestinal Stromal Tumors: Translational Implications, David Reynoso

Dissertations & Theses (Open Access)

Gastrointestinal stromal tumors (GISTs) are oncogene-addicted cancers driven by activating mutations in the genes encoding receptor tyrosine kinases KIT and PDGFR-α. Imatinib mesylate, a specific inhibitor of KIT and PDGFR-α signaling, delays progression of GIST, but is incapable of achieving cure. Thus, most patients who initially respond to imatinib therapy eventually experience tumor progression, and have limited therapeutic options thereafter. To address imatinib-resistance and tumor progression, these studies sought to understand the molecular mechanisms that regulate apoptosis in GIST, and evaluate combination therapies that kill GISTs cells via complementary, but independent, mechanisms. BIM (Bcl-2 interacting mediator …