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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 …

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 …

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 …

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 …

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 …

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. …

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 …

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 …

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 …

Microrna-200 Regulates Ecm-Dependent Β1-Integrin/Fak Signaling And Cancer Cell Invasion, Christin Ungewiss

Dissertations & Theses (Open Access)

The microRNA-200 family is known to be a master regulator of the epithelial-to-mesenchymal transition, partially through its double-negative feedback loop with the transcriptional repressor Zeb1, yet the mechanisms on how miR-200 controls the invasive phenotype are not fully understood. Recent studies have shown that the miR-200/Zeb1 axis regulates cell-cell and cell-matrix interactions, but it has also been demonstrated that cell-intrinsic changes are insufficient to drive cancer cell invasion, leading us to focus on specific cell-matrix interactions required to activate tumor cell invasion and metastases. We have shown through 3D studies that the Integrin β1-collagen I contact is critical in mediating …

Targeting Cox-2 And Rank In Aggressive Breast Cancers: Inflammatory Breast Cancer And Triple-Negative Breast Cancer, Monica Elizabeth Reyes

Dissertations & Theses (Open Access)

Inflammatory breast cancer (IBC) and triple-negative breast cancer (TNBC) are two highly aggressive breast cancer subtypes associated with a poor outcome. Despite sensitivity to current treatment, these breast cancers subtypes have a high recurrence rate and proclivity to metastasize early. The aggressiveness of IBC and TNBC have been linked to CSCs and epithelial to mesenchymal transition (EMT), which are critical features of breast cancer progression and metastasis. The clinical challenge faced in the treatment of IBC and TNBC is finding a treatment strategy to target the cancer stem-like (CSC) population to block metastasis. Cyclooxygenase-2 (COX-2) and receptor activator of nuclear …

Inhibition Of Pim And Axl Kinases As Potential Treatments For A Variety Of Hematological Malignancies And Solid Tumors, Kent James Carpenter

Theses and Dissertations

This thesis is divided into three chapters. In each case, the goal is to achieve inhibition of a growth kinase (PIM or AXL) and subsequent arrest of cell growth and induction of apoptosis (in vitro cell culture models) or decrease in tumor volume (in vivo xenograft studies). Chapter one and chapter two discuss inhibition of proviral integration site for Moloneymurine leukemia virus (PIM) kinases. The three PIM kinases, PIM-1, PIM-2, and PIM-3, are a subfamily of serine/threonine kinases that are known to be involved in signaling pathways as downstream effectors of signal transducer and activator of transcription-5 (STAT5) signaling and …

The P63 Isoform ∆Np63Α Inhibits Epithelial – Mesenchymal Transition By Promoting The Expression Of Mir-205 In Human Bladder Cancer Cells, Mai Tran

Dissertations & Theses (Open Access)

p63, a p53 family member, is a transcription factor that has complex roles in cancer. This study focuses on the role of the ∆Np63α isoform in bladder cancer (BC). Epithelial – mesenchymal transition (EMT) is a physiological process that plays an important part in metastasis and drug resistance. At the molecular level, EMT is characterized by the loss of the epithelial marker E-cadherin, and the acquisition of the transcriptional repressors of E-cadherin (ZEB1, ZEB2, TWIST, SNAI1 and SNAI2). Recent publications highlight the role of microRNAs belonging to the miR-200 family and miR-205 in preventing EMT through suppression of ZEB1 and …

The Embryonic Protein Nodal Supports Metastatic Phenotypes In Breast Cancer, Daniela F. Quail

Electronic Thesis and Dissertation Repository

Metastasis is the process by which tumour cells disseminate to distant organ sites. Aberrant expression of stem cell-associated proteins within tumours is associated with metastasis and poor patient prognosis. One example of a stem cell factor that is associated with cancer progression is Nodal, a member of the TGF-β superfamily. Nodal is normally limited to pluripotent stem cells during embryonic development, and to specialized dynamic adult tissue (such as the cycling endometrium), but is aberrantly re-expressed in multiple cancer types, including melanoma, glioma, prostate cancer, and pancreatic cancer. The central objective of this thesis is to determine the role of …

Nherf1 – New Modifier Of Colorectal Cancer Progression, Yuho Hayashi

Dissertations & Theses (Open Access)

Colorectal cancer (CRC) develops from multiple progressive modifications of normal intestinal epithelium into adenocarcinoma. Loss of cell polarity has been implicated as an early event in this process, but the molecular players involved are not well known. NHERF1 (Na+/H+ Exchanger Regulatory Factor 1) is an adaptor protein with apical membrane localization in polarized epithelia. In this study, we tested our hypothesis that NHERF1 plays a role in CRC. We examined surgical CRC resection specimens for changes in NHERF1 expression, and modeled these changes in two- and three-dimensional (2D and 3D) Caco-2 CRC cell systems. NHERF1 had significant alterations from normal …