Medicine and Health Sciences Commons^™

Clinical And Pathologic Significance Of Integrin Α6Β4 Expression In Human Malignancies, Rachel L. Stewart

Theses and Dissertations--Clinical and Translational Science

Integrins are cellular adhesion molecules that bind cells to the extracellular matrix. The integrin α6β4, a receptor for laminins, is predominantly expressed on epithelial cells where it is present at the basal surface adjacent to the basement membrane. This integrin plays a critical role in maintaining normal cellular functions, yet has also been implicated in promoting invasion and metastasis in human malignancies. While overexpression of the integrin α6β4 has been detected in select human cancers, the clinical significance of integrin α6β4 expression in a number of malignancies has not been determined. The purpose of this study was to examine integrin …

A Study On The Function Of 14-3-3sigma In Regulating Cancer Energy Metabolism, Liem M. Phan, Liem M. Phan

Dissertations & Theses (Open Access)

Metabolic reprogramming has been shown to be a major cancer hallmark providing tumor cells with significant advantages for survival, proliferation, growth, metastasis and resistance against anti-cancer therapies. Glycolysis, glutaminolysis and mitochondrial biogenesis are among the most essential cancer metabolic alterations because these pathways provide cancer cells with not only energy but also crucial metabolites to support large-scale biosynthesis, rapid proliferation and tumorigenesis. In this study, we find that 14-3-3σ suppresses all these three metabolic processes by promoting the degradation of their main driver, c-Myc. In fact, 14-3-3s significantly enhances c-Myc poly-ubiquitination and subsequent degradation, reduces c-Myc transcriptional activity, and down-regulates …

Platelets And Anti-Angiogenic Resistance In Ovarian Carcinoma, Justin N. Bottsford-Miller

Dissertations & Theses (Open Access)

Background: Resistance to targeted anti-angiogenic therapy is a growing clinical concern given the disappointing clinical impact of anti-angiogenic. Platelets represent a component of the tumor microenvironment that are implicated in metastasis and represent a significant reservoir of angiogenic regulators. Thrombocytosis has been shown to be caused by malignancy and associated with adverse clinical outcomes, however the causal connections between these associations remain to be identified.

Materials and Methods: Following IRB approval, patient data were collected on patients from four U.S. centers and platelet levels through and after therapy were considered as indicators of recurrence of disease. In vitro effects of …

Rok And Rac Mediation Of Prl-1 Function In The Wings Of Drosophila Melanogaster, Rosemary Dinkins

Honors Program Theses

By the time a cancer metastasizes it has reached its most deadly stage. It therefore is essential that the underpinning mechanisms promoting metastasis are understood. Phosphatases of regenerating liver (PRL) have been repeatedly connected to cancer metastasis when overexpressed. However, little is yet known about the normal PRL function and biological pathways let alone the PRL pathway promoting metastasis. The current study explores the relationship between PRL-1 and two other genes, ROK and Rac,that have also been implicated in cell migration and metastasis. Increased PRL-1 function in conjunction with increased or decreased Rac function was forced to the dorsal half …

Increased Geranylgeranylated K-Ras Contributes To Antineoplastic Effects Of Farnesyltransferase Inhibitors., Mandy A. Hall

Dissertations & Theses (Open Access)

The Ras family of small GTPases (N-, H-, and K-Ras) is a group of important signaling mediators. Ras is frequently activated in some cancers, while others maintain low level activity to achieve optimal cell growth. In cells with endogenously low levels of active Ras, increasing Ras signaling through the ERK and p38 MAPK pathways can cause growth arrest or cell death. Ras requires prenylation – the addition of a 15-carbon (farnesyl) or 20-carbon (geranylgeranyl) group – to keep the protein anchored into membranes for effective signaling. N- and K-Ras can be alternatively geranylgeranylated (GG’d) if farnesylation is inhibited but are …

Atm Signaling To Tsc2: Mechanisms And Implications For Cancer Therapy, Angela Alexander

Dissertations & Theses (Open Access)

Ataxia telangiectasia mutated (ATM) is a critical component of the cellular response to DNA damage, where it acts as a damage sensor, and signals to a large network of proteins which execute the important tasks involved in responding to the damage, namely inducing cell cycle checkpoints, inducing DNA repair, modulating transcriptional responses, and regulating cell death pathways if the damage cannot be repaired faithfully. We have now discovered that an additional novel component of this ATM-dependent damage response involves induction of autophagy in response to oxidative stress. In contrast to DNA damage-induced ATM activation however, oxidative stress induced ATM, occurs …

Alterations In Calcium Homeostasis And The Insulin-Like Growth Factor Signaling Pathway Induced By Carcinogenic Polycyclic And Halogenated Aromatic Hydrocarbons In Human Mammary Epithelial Cells, Stacey L. Tannheimer

Pharmaceutical Sciences ETDs

Breast cancer is a major health concern for women, with only a small percent of the risk factors currently identified. It has been estimated that environmental factors may contribute to up to 80% of breast cancer cases. Many environmental carcinogens, such as polycyclic and halogenated aromatic hydrocarbons (PAHs and HAHs), are proven mammary carcinogens in animal models. Therefore, these studies were conducted to elucidate potential roles of PAHs and HAHs in alterations in known signaling pathways in human mammary epithelial cells (HMEC). Carcinogenic PAHs have previously been shown to produce sustained alterations in the calcium (Ca2') homeostasis of lymphocytes Therefore, …