Medicine and Health Sciences Commons^™

Absolute Quantification Of Tc-99m Activity Distributions Using A Planar Molecular Breast Imaging Commercial System, Benjamin P. Lopez

Dissertations & Theses (Open Access)

Molecular breast imaging (MBI) uses two dedicated-breast semiconductor detectors to visualize the preferential uptake of technetium-99m-sestamibi (^99mTc-sestamibi) by breast cancer cells relative to surrounding benign breast tissues. Clinically, MBI is used primarily as a supplementary tool to standard-of-care mammography because of its improved detection of breast cancers, especially in women with mammographically-dense breasts. Because of a lack of image corrections, MBI applications are currently limited to qualitative evaluations of relative pixel intensities between image regions with suspected lesions and normal tissue.

The objective of this dissertation was to use Monte Carlo simulations to better characterize the MBI imaging …

Computational Approaches To Understand Chemoresistance & Tumor Evolution Using Longitudinal Clinical Data And Lineage Tracing, Sahil Seth

Dissertations & Theses (Open Access)

Tumors are highly heterogeneous and dynamic, continually adapting and evolving in response to their microenvironment as well as external perturbations. Multi-region (spatial) and single cell sequencing has enabled us to anatomize the heterogeneity further and provide evidence of its association with chemo and drug resistance. To investigate this further we took two different approaches to understand the chemo-resistance, and functional heterogeneity in Triple negative breast cancer (TNBC) and Pancreatic ductal carcinoma in situ (PDAC) from an evolutionary perspective.

The first approach was to leverage tumor profiling from an ongoing randomized clinical trial in triple-negative breast cancer (ARTEMIS) to assess mechanisms …

Exploration Of Breastfeeding As A Protective Factor For Breast Cancer In South African Women: A Nested Case-Control Study, Quiera S. Booker

Dissertations & Theses (Open Access)

South African’s (SA) breast cancer incidence rate is continually increasing (39 per 100,000 (2012) versus 46.2 per 100,000 (2018) with trends towards later-stage diagnosis. In previous literature, breastfeeding has been assessed as a protective factor for breast cancer; however, the SA population experiences inconsistent breastfeeding trends, rates, and support services. Therefore, this study will evaluate the inverse association between breast cancer and breastfeeding history. Methods. Cases (breast cancer) and controls (mastalgia) were matched 1:1 on clinical visit from May-August 2019 at Groote Schuur Hospital (GSH) in Cape Town, Western Cape, South Africa. Breastfeeding history, breast carcinoma diagnosis, and clinically relevant …

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 …

Understanding The Relatlonships Between Survivorship Care Plans And Survivor Level Outcomes Among Breast And Colorectal Cancer Survivors, Jessica Danielle Austin

Dissertations & Theses (Open Access)

PURPOSE: Cancer survivors have complex journeys following the completion of active treatment. The Institute of Medicine and other high-profile organizations have recommended and mandated the use of a survivorship care plan (SCP) despite mixed evidence supporting the impact of SCPs on key survivor-level outcomes. The purpose of this dissertation was to understand the complex relationship linking the delivery of SCPs and to relevant survivorlevel outcomes. STUDY GROUP: This dissertation focuses on breast and colorectal cancer survivors because they comprise nearly 30% of the entire cancer survivor population in the US and are the two most prevalent cancers in men and …

The Epithelial To Mesenchymal Transition In Breast Cancer Induces Alterations In Metabolism, Esmeralda Ramirez-Peña

Dissertations & Theses (Open Access)

Metastasis is currently incurable. Recent studies suggest that metabolic reprogramming significantly impacts metastatic progression. Understanding the underlying biology of how metabolic reprogramming influences metastasis will shed light on developing novel ways to treat metastasis and is of urgent clinical need. A potent mediator of metastatic potential in breast cancer is the winged helix/Forkhead domain transcription factor FOXC2. We have previously shown that FOXC2 is necessary and sufficient to promote metastasis through induction of the epithelial to mesenchymal transition (EMT). EMT is a latent embryonic program that is aberrantly induced in breast cancer cells conferring migratory and invasive capabilities in addition …

Quality Of Life: Socio-Demographic And Genetic Determinants As Well As Links With Cancer Outcomes, Jeanne Pierzynski

Dissertations & Theses (Open Access)

Quality of life (QOL) is an independent prognostic factor for cancer. Lung cancer is the leading cause of cancer death. Breast cancer is the most diagnosed. Bladder cancer is the most expensive cancer to treat because of its high recurrence rate. We set to perform comprehensive analyses of predictors of QOL in these cancer sites with the future goal of improving QOL and outcomes.

In 6,456 newly diagnosed lung cancer patients, we investigated the relationship between baseline patient characteristics and QOL to identify determinants of QOL. A QOL questionnaire (SF-12v1) measured patients’ physical component summary (PCS) and mental component summary …

Regulation Of Breast Cancer Initiation And Progression By 14-3-3zeta, Chia-Chi Chang

Dissertations & Theses (Open Access)

14-3-3ζ is a ubiquitously expressed family member of proteins that have been implicated to have oncogenic potential through its interactions and involvement in cancer initiation and progression. 14-3-3ζ belongs to the highly conserved 14-3-3ζ protein family and modulates numerous pathways in cancer. Overexpression of 14-3-3ζ is an early event, occurs in more than 40% of human breast cancer cases, and is associated with disease recurrence and poor prognosis. Metabolic reprogramming is a hallmark of cancer. Cancer cells elevate aerobic glycolysis to produce metabolic intermediates and reducing equivalents, thereby facilitating cellular adaptation to the adverse environment and sustaining fast proliferation. Interestingly, …

The Roles Of Malt1 In Nf-Κb Activation And Solid Tumor Progression, Deng Pan

Dissertations & Theses (Open Access)

The transcription factor NF-κB plays a central role in many aspects of biological processes and diseases, such as inflammation and cancer. Although it has been suggested thatNF-κB is critical in tumorigenesis and tumor progression, the molecular mechanism by which NF-κB is activated in solid tumor remains largely unknown. In the current work, we focus on growth factor receptor-induced NF-κB activation and tumor progression, including epidermal growth factor receptor (EGFR)-induced NF-κB in lung cancer and heregulin receptor (HER2)-induced NF-κB in breast cancer. We found that Mucosa-associated lymphoma translocation protein 1 (MALT1), also known as paracaspase, is required for EGFR-induced NF-κB activation …

Trim28 Interacts With Ezh2 To Regulate Its Activity, Jing Li, Jing Li

Dissertations & Theses (Open Access)

In this dissertation, I discovered that TRIM28 interacts with EZH2 and regulates its activity in breast cancer cells. EZH2, the major H3K27 tri-methyltransferase, is over expressed in multiple subtypes of breast cancer; however, whether EZH2 plays an active role in breast cancer progression or treatment resistance is unknown. Here, we determined EZH2-interacting proteins in MCF7 cells by immunoprecipitation/mass spectrometry and detected TRIM28 with a high confidence score. TRIM28 is a transcription co-regulator with an N-terminal tri-partite RING finger, B-boxes and a coiled-coil domain (RBCC) and a C-terminal PHD/Bromo domain. Domain mapping revealed that the RBCC domain of TRIM28 interacts with …

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 …

Nprl2/Tusc4 Functions As A Tumor Suppressor By Regulating Brca1’S Stability Via The E3 Ubiquitination Pathway, Yang Peng

Dissertations & Theses (Open Access)

Expression of the tumor suppressor protein BRCA1 is frequently lost in breast cancer patients, and the loss of its expression is associated with disruption of various critical functions in cells and cancer development. In the present study, we demonstrate through microarray analysis that cells with tumor suppressor candidate 4 (NPRL2/TUSC4) knockdown show critical changes to cell cycle, cell death pathways and a global impact on cancer development. More importantly, we observed a clear cluster pattern of NPRL2/TUSC4-knockdown gene profiles with established homologous recombination (HR) repair defect signature. Additionally, NPRL2/TUSC4 protein physically interacts with the E3 ligase HERC2 and prevents ubiquitin …

Imbalance Between Neutrophil Elastase And Elafin Promotes Breast Cancer Growth And Progression, Joseph Anthony Caruso

Dissertations & Theses (Open Access)

Elafin, an endogenous serine protease inhibitor, is a critical component of the epithelial barrier against neutrophil elastase (NE) activity. The central hypothesis examined in this dissertation was that elafin has tumor suppressive properties in breast cancer. In support of this hypothesis, immunohistochemical (IHC) analysis revealed that elafin was downregulated in the majority of invasive breast tumors and a subset of pre-invasive ductal carcinoma in situ (DCIS) compared to elafin expression in the normal mammary epithelium. To understand the role of elafin in the mammary epithelium and the impetus for its downregulation during breast tumorigenesis, primary and immortalized human mammary epithelial …

Targeting Breast Cancer With Bacteriophage Associated Silicon Particles, Srimeenakshi Srinivasan

Dissertations & Theses (Open Access)

Nanoparticle based therapeutics have been successfully used in the treatment of breast cancer. Development of nanovectors targeted to cancer cells or elements in the tumor microenvironment has been pursued to improve their site specific accumulation while reducing the non-specific delivery to normal tissues. However, addition of targeting ligands to the surface of nanovectors while maintaining their payload carrying potential is generally challenging. Therefore, there is a critical need to develop surface decoration strategies that allow for effective combination of targeting and payload delivery to the tumor.

In this study, we propose a novel strategy for covering the surface of mesoporous …

Basis For Targeting Met Activation Mediated Resistance To Pi3k Inhibition In Breast Cancer, Ana M. Gonzalez-Angulo

Dissertations & Theses (Open Access)

The identification of resistance mechanisms to emerging therapies, such as those targeting the PI3K pathway and the MET receptor, has the potential to benefit a significant number of patients with breast cancer. In this study we hypothesized that concurrent aberrations in PI3K and MET will render breast cancers resistant to therapies targeting each pathway, and that combination therapy targeting the PI3K and MET pathway will optimize therapy-effect by preventing the acquisition of resistance.

We analyzed cMET and phospho-cMET levels in 257 breast cancer samples and found that high levels of both the proteins were seen in all breast cancer subtypes, …