The Interplay Between Lung Adenocarcinoma, Nutrient Availability, And The Microbiome., Alexis A. Vega

Electronic Theses and Dissertations

Lung cancer is one of the most common forms of cancer diagnosed, and has the highest lethality rate across all other forms of cancer in the U.S. While current therapeutic options include chemo-, immuno-, and radio-therapy, the benefits of caloric or nutrient restriction on cancer cells has also been investigated. Due to the many biological functions associated with methionine, many have proposed a methionine restricted diet would lead to favorable outcomes when combating cancer. Although our cells are incapable of synthesizing methionine, the bacteria found in our microbiome can. Furthermore, recent discoveries suggest an independent microbiome found within tumors that …

Uncovering Molecular Targets To Overcome Immunosuppression In Non-Small Cell Lung Cancer With Acquired Tki Resistance, Sonia A. Patel

Dissertations & Theses (Open Access)

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related deaths worldwide. Targeted therapeutic agents, such as epidermal-like growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) or monoclonal antibodies targeting vascular endothelial growth factor (VEGF/R), can effectively inhibit upregulated signaling pathways driving tumorigenesis in NSCLC and many other cancers. Unfortunately, however, resistance to such targeted therapies inevitably arise in most patients and can occur through a variety of resistance mechanisms including genomic alterations and upregulation of bypass pathways. Additionally, patients who have acquired resistance to these targeted agents typically have tumors characterized by an immunosuppressive tumor microenvironment and thus …

Post-Transcriptional Control Of The Epithelial-To-Mesenchymal Transition (Emt) In Ras-Driven Colorectal Cancers, Chaitra Rao

Theses & Dissertations

Colorectal cancer (CRC) originates from epithelial cells lining the colon or rectum of the gastrointestinal tract. Most cancer deaths result from a tumor spreading to distant organs; however epithelial cells do not normally migrate from their tissue of origin. To do so, epithelial cells undergo biochemical changes allowing them to acquire behavior similar to motile mesenchymal cells termed the epithelial-to-mesenchymal transition (EMT), which contributes to tumor invasion and metastasis. Our study demonstrated that CRC cells require a molecular scaffold, Kinase Suppressor of Ras 1 (KSR1), and ERK to promote the EMT-like phenotype through the preferential translation of Epithelial Stromal Interaction …

The Roles Of Epithelial–Mesenchymal Plasticity In Tumor Heterogeneity, Metastasis, And Patient Survival In Breast Cancer, Meredith Septer Brown

Dartmouth College Ph.D Dissertations

The Epithelial-to-Mesenchymal transition, a critical cellular process in development, is frequently co-opted by solid tumors to promote invasion and metastasis. In particular, the hybrid or intermediate EMT state, possessing both epithelial and mesenchymal characteristics, is associated with increased cancer stemness and plasticity. Similarly, intra-tumoral heterogeneity in solid tumors, in particular breast cancer, is associated with poor prognosis, tumor growth, proliferation, drug resistance, and metastasis. We sought to understand the link between the generation of intra-tumoral heterogeneity and the intermediate EMT state and their impact on tumor progression and patient prognosis. As part of my thesis work, I developed a model …

Dissecting Tumor Heterogeneity In Lung Cancer, Aparna Padhye

Dissertations & Theses (Open Access)

Lung cancer is a heterogeneous disease composed of genetically and phenotypically distinct tumor cells as well as a heterogeneous microenvironment consisting of non-cancer cells and extracellular matrix. Constant interactions among these components ultimately leads to a complex tumor tissue that is ever evolving and poses a therapeutic challenge for sustained benefit. Strategies for targeting lung cancers are largely guided by the genetic alterations identified in the tumor specimens. However, in order to gain a better understanding of lung cancer progression and develop effective treatment modalities, studying tumor in context of its microenvironment is crucial. The first aim of this project …

Molecular Drivers Of Bladder Cancer Motility, Bryan Wehrenberg

Dissertations & Theses (Open Access)

Bladder cancer (BC) progression is measured by the degree of tumor cell invasion into the bladder wall and dissemination to distant sites. The study of BC cell motility will both enable development of anti-invasion therapeutics to limit progression of early-stage disease and improve our understanding of the metastatic process which drives patient mortality in BC. BCs display a great deal of intertumoral heterogeneity, and can be divided into basal and luminal subtypes, which are biologically and clinically distinct entities. Here, I examine the invasion phenotypes of BC as a function of both subtype and epithelial to mesenchymal transition (EMT) status. …

Epithelial-Mesenchymal Status Predics Tumor Agressivenss, Chemoresistance And Invasiveness In High Grade Serous Ovarian Cancer, Linda Sanderman

Electronic Theses, Projects, and Dissertations

High Grade Serous Ovarian Cancer (HGSOC) is one of the deadliest gynecological diseases in the United States ranking fifth in cancer deaths among women. Approximately 22 thousand new cases are expected to occur in the year 2020, and unfortunately, it is estimated that 14 thousand women will succumb to the disease; the incidence to death ratio, 64%, remains high despite current research. Current treatment includes debulking surgery followed by combinatorial chemotherapeutics with platinum-based and taxol-based compounds. But despite aggressive surgery and standard-of-care chemotherapeutics, 80% of patients will experience a recurrence and only 15-30% of those with recurring disease will respond …

Molecular Mechanisms Underlying Migratory And Immune-Evasion Properties Of Circulating Tumor Cells, Jeannette A. Huaman

Dissertations, Theses, and Capstone Projects

Metastasis is the leading cause of cancer deaths worldwide. However, there exist only limited treatment options and they are often ineffective. An important aspect of metastasis that requires study, but has previously been understudied is circulating tumor cells (CTCs). CTCs are a critical step in the metastatic cascade. They can be analyzed for the identification of key mechanisms in metastasis. To this end, we isolated CTCs from a syngeneic mouse model of hepatocellular carcinoma (HCC) and a human xenograft mouse model of castration-resistant prostate cancer (CRPC). From these mouse models, primary tumor and CTC lines were established. Functional characterization of …

Grainyhead-Like 2 Sensitizes Cells To Natural Killer Cell Cytotoxicity And Promotes The Interferon Response, Ian Philip Macfawn

Graduate Theses, Dissertations, and Problem Reports

Our research determined that the epithelial master transcription factor Grainyhead-like 2 (GRHL2) promotes sensitivity to Natural Killer (NK) cell-mediated killing, and modulates the interferon I (IFN-I) response of epithelial cells. Immune surveillance by NK cells constitutes a major selective pressure for circulating tumor cells. Epithelial (GRHL2-expressing) cells exhibited significantly higher rates of NK conjugation, a crucial step in direct cell-mediated cytotoxicity. Mechanistically, GRHL2 upregulates expression of intercellular adhesion molecule 1 (ICAM-1), a cell surface molecule critical for NK to target cell synaptogenesis. GRHL2 epigenetically regulates gene expression, and we found that GRHL2 mutant proteins unable to interact with the epigenetic …

The Identification Of Long Non-Coding Rna Zfas1 Through An Exploratory Rna-Sequencing Analysis And Its Association With Epithelial-To-Mesenchymal Transition In Colon Cancer Adenocarcinoma., Stephen J. O'Brien

Electronic Theses and Dissertations

Colorectal adenocarcinoma is the fourth most common cancer diagnosed worldwide and is a significant cause of morbidity and mortality. This dissertation performed an exploratory RNA-sequencing analysis comparing gene expression between colon adenocarcinoma tissue and paired normal colon epithelium. After identification of a number of lncRNAs that were increased in expression in colon adenocarcinoma compared to normal colon epithelium, we aimed to validate the expression and investigate their function in vitro. Specifically, we focused on the lncRNA ZFAS1 and its association with epithelial-to-mesenchymal transition. These studies found the following: 1. Seven candidate lncRNAs were identified from the exploratory RNA-sequencing analysis to …

Deubiquitinating Enzymes Promote Cancer Progression And Metastasis Via Regulating Protein Stability, Zhenna Xiao

Dissertations & Theses (Open Access)

Deubiquitinating enzymes (DUBs, also called deubiquitinases) are enzymes that remove monoubiquitin or polyubiquitin chains from target proteins. DUBs have critical roles in cell homeostasis and signal transduction, as they regulate protein degradation, subcellular localization, and protein-protein interaction. Deregulation of DUBs contributes substantially to tumor formation and progression, and therefore targeting DUBs may be a promising cancer therapy strategy. My dissertation focuses on identifying the DUBs of EZH2 and SNAI1, two proteins critical for cancer progression and metastasis, and establishing these DUBs as promising anti-cancer targets.

EZH2, the catalytic component of the PRC2 complex, silences gene transcription by histone methylation. High …

Role Of Transient Receptor Potential Channels In Epithelial Morphogenesis In Chick Embryo, Trinity Q. Waddell

Theses and Dissertations

Transient Receptor Potential channels (TRP) are a superfamily of cationic specific ionchannels that are regulated by various stimuli such as temperature, pH, mechanical stress, ligandsand ion concentration. The role of TRP channels in disease states such as autosomal dominantpolycystic kidney disease, cancer metastasis, and developmental defects lend credence to thebelief that they play an important part in epithelial morphogenesis events. The development ofsomites, neural tube closure and migration of neural crest cells to form things such as the faceand heart is a good developmental model for the aforementioned cellular processes. We haveshown that TRP channels can be found in the …

The Role Of P62/Imp2 In Hepatocellular Carcinoma Progression, Mengtao Xing

Open Access Theses & Dissertations

The family of insulin- like growth factor 2 mRNA binding proteins (IMPs) contains three members: IMP1, p62/IMP2 and IMP3. All these proteins are oncofetal proteins, expressed during embryogenesis and lost in most tissues in adults. However, p62/IMP2 were found overexpressed in various cancers but its function in carcinogenesis remains to be investigated. Our previous studies found that p62/IMP2 was not only overexpressed in hepatocellular carcinoma (HCC) tissues, but also overexpressed in HCC cell lines. To explore the biological roles of p62/IMP2 in HCC progression, p62/IMP2 was knockout in two p62/IMP2 positive HCC cell lines (SNU449, HepG2). Due to the low …

The Role Of Tumor Suppressor Dear1 In The Acquisition Of Mammary Stem/Progenitor Cell Properties, Uyen Le

Dissertations & Theses (Open Access)

Breast cancer is the most commonly diagnosed cancer in women in America. Ductal carcinoma in situ (DCIS), one of the earliest pre-invasive forms of invasive ductal carcinoma (IDC), has a 30-50% risk of progressing to IDC. Understanding the mechanisms regulating progression from DCIS to IDC would help identify biomarkers to stratify patients at higher risk of progression or metastasis. Cumulative literature suggests the earliest phase of dissemination from the primary tumor is driven by the epithelial-mesenchymal transition (EMT) program. DEAR1 is a tumor suppressor gene which is mutated, undergoes loss of heterozygosity in breast cancer, and is downregulated in DCIS …

Trim24 As An Oncogene In The Mammary Gland, Aundrietta Duncan

Dissertations & Theses (Open Access)

Despite the many advances made in breast cancer research and treatments, breast cancer remains one of the deadliest diseases plaguing women worldwide. While many findings on genetic mutations and their role in predisposing people to breast cancer have been uncovered, we are just beginning to understand the extent to which epigenetic regulators promote tumorigenic phenotypes, metastasis, and chemotherapeutic resistance. Moreover, new experimental tools offer the ability to address questions we were previously unable to assess. My project takes advantage of a new mouse model to understand the role of a proto-oncogenic, transcriptional co-regulator, TRIM24, in mammary gland development and disease. …

Epithelial To Mesenchymal Transition As A Predictor Of Response To Polo-Like Kinase 1 Inhibition-Induced Apoptosis In Non-Small Cell Lung Carcinoma, Pavitra Viswanath

Dissertations & Theses (Open Access)

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. Outcomes are poor for patients with recurrent, advanced or metastatic NSCLC. Polo-like kinase 1 (PLK1), involved in the regulation of mitotic processes and the response to DNA damage, is overexpressed in NSCLC. Inhibiting PLK1 may be an effective treatment for NSCLC patients as it is involved in the mechanisms of resistance to several chemotherapy drugs. PLK1 inhibition or knock-down has various effects in cancer cells, including mitotic arrest, apoptosis, and senescence. Predictive biomarkers have not been identified to select those patients who are likely to respond to …

Deciphering The Roles Of Δnp63 In Regulating Epithelial To Mesenchymal Transition, Cancer Progression And Metastasis, Ngoc Bui

Dissertations & Theses (Open Access)

p63 is a member of the p53 family, a well-known tumor suppressor which is considered the guardian of the genome. The TP63 gene encodes multiple isoforms that can be categorized into two main isoforms, TAp63 and ΔNp63, which are expressed in different cellular compartments and have distinct functions in many biological processes. While the Flores laboratory identified TAp63 as a tumor and metastasis suppressor, the precise roles of ΔNp63 isoforms in tumorigenesis and metastasis remain elusive. ΔNp63 is the predominant p63 isoform expressed in the epidermis and plays essential roles in regulating epidermal development and homeostasis. Utilizing a ΔNp63-conditional …

Exogenous Fniii 12-14 Regulates Tgf-Β1-Induced Markers, Hilmi M. Humeid

Theses and Dissertations

The extracellular matrix protein Fibronectin (FN) plays an important role in cell contractility, differentiation, growth, adhesion, and migration. The 12th -14th Type III repeats of FN (FNIII 12-14), also referred to as the Heparin-II domain, comprise a highly promiscuous growth factor (GF) binding region. This binding domain aids in cellular signaling initiated from the ECM. Additionally, FN has the ability to assemble into fibrils under certain conditions, mostly observed during cell contractile processes such as those that initiate due to upregulation of Transforming Growth Factor Beta 1 (TGF-β1) [1], [2]. Previous work from our lab has shown that self-assembly of …

The Role Of The Epithelial-To-Mesenchymal Transition (Emt) In Lung Cancer Progression, David H. Peng

Dissertations & Theses (Open Access)

Lung cancer is the leading cause of cancer-related deaths due to conventional therapy resistance and metastatic disease, therefore understanding the mechanisms governing these biological functions is vital for improving patient survival. Approximately 30% of patients with the adenocarcinoma histologic subset of lung cancer possess an activating KRAS mutation, characterized by a lack of response to chemotherapies with a poor overall 5-year survival rate. Despite the mutational frequency, KRAS remains a challenge to pharmacologically inhibit and current drugs undergoing clinical trials that target specific downstream effector proteins of KRAS, such as MEK inhibitors, have failed to produce significant clinical benefits. Previous …

Gsk3b Regulates Epithelial-Mesenchymal Transition And Cancer Stem Cell Properties And Is A Novel Drug Target For Triple-Negative Breast Cancer, Geraldine Vidhya Raja

Dissertations & Theses (Open Access)

Abstract

GSK3β regulates Epithelial-Mesenchymal-Transition and Cancer Stem Cell properties and is a novel drug target for Triple-Negative Breast Cancer.

Geraldine Vidhya Raja, MS.

Advisory Professor: Sendurai Mani, Ph.D.

Triple-Negative breast cancers (TNBCs) are highly aggressive and lack the expression of Estrogen Receptor (ER), Progesterone Receptor (PR) as well as Human Epidermal Growth Factor Receptor (HER2). Consequently, patients diagnosed with TNBCs have poor overall- and disease-free survival rates compared to other subtypes of breast cancer due to lack of targeted therapies as well as de novo or acquired chemoresistance, disease recurrence, and lack of targeted therapy. Hence it is critical to …

The Role Of Cytoplasmic Polyadenylation Element Binding Protein -2 (Cpeb-2) In Human Breast Cancer, Joshua Tordjman

Electronic Thesis and Dissertation Repository

Cyclooxygenase-2 (COX-2) is overexpressed in 40-50% of breast cancers, and promotes tumour progression through increased proliferation, migration, invasion, Epithelial-to-Mesenchymal Transition (EMT), and induction of therapy-resistant Stem-Like-Cells (SLCs). COX-2 stimulates expression of two oncogenic and SLC-promoting microRNAs (miR-526b, miR-655), which simultaneously target one gene, Cytoplasmic Polyadenylation Element Binding Protein-2 (CPEB-2). Hypothesis: CPEB-2 is a tumour- and SLC-suppressing gene in breast cancer. Results: CPEB-2 knockout in a non-tumourigenic mammary epithelial cell line MCF10A demonstrated increases in proliferation, migration, invasion, EMT markers, SLC content, and VEGF-D expression. CPEB-2, an mRNA-binding translation-regulating protein, was found to regulate the translation of tumour suppressor p53. When …

Non-Coding Rnas Identify The Intrinsic Molecular Subtypes Of Muscle-Invasive Bladder Cancer, Andrea E. Ochoa

Dissertations & Theses (Open Access)

NON-CODING RNAS IDENTIFY THE INTRINSIC MOLECULAR SUBTYPES OF MUSCLE-INVASIVE BLADDER CANCER

Andrea Elizabeth Ochoa, B.S.

Advisory Professors: David J. McConkey, Ph.D. and Joya Chandra, Ph.D.

There has been a recent explosion of genomics data in muscle-invasive bladder cancer (MIBC) to better understand the underlying biology of the disease that leads to the high amount of heterogeneity that is seen clinically. These studies have identified relatively stable intrinsic molecular subtypes of MIBC that show similarities to the basal and luminal subtypes of breast cancer. However, previous studies have primarily focused on protein-coding genes or DNA mutations/alterations.

There is emerging evidence implicating …

Functional And Mechanistic Consequences Of Dual Oxidase 1 Suppression In Lung Cancer, Andrew Charles Little

Graduate College Dissertations and Theses

The NADPH oxidase homolog, dual oxidase 1 (DUOX1), is an H2O2 producing transmembrane enzyme highly expressed in the airway epithelium. DUOX1-dependent redox signaling has been characterized to regulate many homeostatic processes in the lung epithelium, such as host defense, wound healing, and type II immune responses. Intriguingly, DUOX1 has been found to be suppressed in many epithelial cancers, including lung cancer, by hypermethylation of its promoter. Epigenetic silencing of DUOX1 in cancer is paradoxical to the understanding that tumors harbor elevated levels of reactive oxygen species (ROS), suggesting that DUOX1 may be a tumor suppressor.

Since DUOX1 loss occurs in …

Syk Promotes Tgf-Beta-Induced P-Body Clearance In Breast Cancer Cells Through The Enhancement Of Autophagy, Shana D. Hardy

Open Access Dissertations

SYK is a protein tyrosine kinase that plays an essential role in the development and activation of immune cells. Its expression, however, is not limited to immune cells. SYK is expressed in a variety of epithelial cell types and epithelial-derived tumors. Reports regarding the role of SYK expression in these diverse cell types and tumors have been opposing. In breast cancer, SYK expression has been overwhelmingly associated with tumor suppression. The loss of Syk expression is observed in invasive breast carcinoma tissue and cell lines and the reintroduction of Syk into metastatic breast cancer cells suppresses tumor growth and metastasis. …

Investigating The Roles Of Δnp63 As A Suppressor Of Migration, Invasion, And Metastasis, Ramon E. Flores Gonzalez

Dissertations & Theses (Open Access)

Cancer is one of the leading causes of death and disease in the world. Considerable resources are spent to study and understand cancer, with the hope of developing new treatments and eventually cures that will help millions of people. Efforts to understand cancer are hindered by its inherent complexity and instability. Nonetheless, understanding the basics of tumor development and progression are the key to focused on studying the role of ΔNp63 in cancer, a p53 family member known to be involved in epithelial development, microRNA biogenesis, and stem cell maintenance. Using the strength of in vivo mouse models, we found …

Role Of Cell Type And Genetic Alterations In Driving Breast Cancer Pathogenesis, Divya Bhagirath

Theses & Dissertations

Breast cancer is the second most leading cause of death among women in the United States. Several environmental and genetic factors contribute to the pathogenesis of the disease. It is classified into different subtypes based on expression of certain markers as well as that of set of genes that define the disease progression and associated mortality. Identification of various subtypes namely: Luminal-like (Luminal-A, Luminal-B), ErbB2 over-expressing, Basal-like and Claudin low types, showed an association of survival outcomes with that of the corresponding gene expression signatures, thus paving a way for therapeutic intervention. It further emphasizes the importance of nature of …

Trim24 Orchestrates Metabolic Reprogramming And Emt In Breast Cancer, Kaushik Thakkar

Dissertations & Theses (Open Access)

In this dissertation, I report the oncogenic functions of an epigenetic regulator Tripartite Motif Protein 24 (TRIM24) coupled with metabolic reprogramming and epithelial mesenchymal transition (EMT) in breast cancer. TRIM24 was first established by our laboratory as a previously unknown negative regulator of p53 via its RING domain, as a co-regulator of nuclear receptors and a PHD/Bromodomain reader of specific histone modifications. TRIM24 expression correlates with poor prognosis of breast cancer, but the mechanisms of TRIM24-mediated oncogenesis are unknown. In the first part of my thesis, I found that TRIM24 is aberrantly expressed in early stages of breast cancer progression. …

Exploring The Regulation And Function Of Epithelial-Mesenchymal Plasticity In Ovarian Cancer Spheroids, Samah Rafehi

Electronic Thesis and Dissertation Repository

Epithelial-mesenchymal transition (EMT) serves as a key mechanism driving tumour cell migration, invasion, and metastasis in many carcinomas. Transforming growth factor-beta (TGFβ) signalling is implicated in several steps during cancer pathogenesis and acts as a classical inducer of EMT. Since epithelial ovarian cancer (EOC) cells have the potential to switch between epithelial and mesenchymal states during metastasis, we predicted that modulation of TGFβ signalling would significantly impact EMT and the malignant potential of EOC spheroid cells. Ovarian cancer patient ascites-derived cells naturally underwent an EMT response when aggregating into spheroids, and this was reversed upon spheroid re-attachment to a …

Forward Chemical Genetics Drug Screen Yields Novel Proteases And Proteolytic Inhibitors Of Hgf–Induced Epithelial–Mesenchymal Transition, Jeffrey Thomas Schuler

Theses and Dissertations

Hepatocyte Growth Factor (HGF)–induced Epithelial–Mesenchymal Transition (EMT) is a complex cellular pathway that causes epithelial cell scattering by breaking cell–cell contacts, eliminating apical–basal polarity, and replacing epithelial markers and characteristics with mesenchymal markers. Early EMT events include a brief period of cell spreading, followed by cell compaction and cell–cell contact breaks. A forward chemical genetics drug screen of 50,000 unique compounds measuring HGF–induced cell scattering identified 26 novel EMT inhibitors, including 2 proteolytic inhibitors. Here, we show that B5500–4, one of the EMT inhibitors from the screen, blocks HGF–induced EMT by a predicted blocking of the protease furin, in addition …

Restriction And Characterization Of Human Breast Cancer Using A Three-Dimensional Embryonic Stem Cell Model, Bridget Mooney

Legacy Theses & Dissertations (2009 - 2024)

Human breast cancer is currently the highest diagnosed form of cancer and the second leading cause of cancer-related deaths in American women. Triple negative breast cancer is of the basal subtype and displays the worst prognosis owing to its highly metastatic properties. Current treatments focused on eradicating breast tumors in lieu of or following local therapy include chemotherapy, hormonal therapy, and targeted therapy. Hormonal therapy is not an option for triple negative breast cancer as it does not contain hormone receptors and there are currently no approved biological targeted therapies. Chemotherapy has proven unsuccessful because triple negative breast cancer is …