Medicine and Health Sciences Commons^™

Exploiting Vulnerabilities In The Ras-Rac Signaling Pathway For The Selective Targeting Of Pancreatic Cancer Cells, Neha Chaudhary

Theses & Dissertations

Deregulation of the KRas (Kirsten rat sarcoma virus) GTPase is one of the early hallmarks of Pancreatic Cancer (PC). The most common genetic alteration found in PC are mutations in the KRas protein that block its ability to hydrolyze GTP to GDP and resulting in higher levels of GTP-bound KRas, its active form. Pancreatic tumors driven by oncogenic mutants of KRas tend to be addicted to the oncogene, to the extent that its repression leads to the induction of cell death. This addiction to the KRAS oncogene makes the KRas protein an ideal target for cancer therapy. However, the globular …

Ewing Sarcoma Transcriptome: Identification Of Foxn3 As A Novel Target Of Ews-Fli1, Natasha Kreiling

Theses & Dissertations

Ewing Sarcoma is an aggressive cancer characterized by a fusion gene formed from a chromosomal translocation between a RNA binding protein and a transcription factor. The most common fusion gene is EWS-FLI1 a potent oncogenic transcription factor responsible for initiating genome instability. EWS-FLI1 promotes tumor growth by dysregulating several genes and pathways. We have identified FOXN3, an important gene in cell cycle control and development, as being suppressed by EWS-FLI1. In the future, a better understanding of FOXN3 and its ability to act as a tumor suppressor in EWS will unravel novel mechanisms of EWS pathogenesis, potential biomarker and drug …

Neuropilin-2 In Advanced Prostate Cancer And Its Targeting With Novel Small Molecule Inhibitors, Ridwan Islam

Theses & Dissertations

Despite the development of new therapies, clinical management of advanced metastatic castrationresistant prostate cancer (mCRPC) still remains challenging owing to the emergence of therapy resistance. Resistance to the therapies is driven by both AR and non-AR pathways. Non-AR pathway is characterized by a lineage switch that leads to the development of neuroendocrine-like (NE-like) prostate cancer (PCa), which has a fulminant clinical course due to the lack of effective treatment strategy. Therefore, novel molecular targets need to be identified to develop effective therapeutic regimen to improve the outcomes in advanced PCa patients including NE-like PCa. Recent investigation on advanced PCa patients …

Dynamics Of Protein-Dna Interactions Characterized By Atomic Force Microscopy, Yaqing Wang

Theses & Dissertations

This thesis describes the nanoscale studies of protein-DNA interactions with different complexities using atomic force microscopy (AFM). One of the systems deals with DNA replication rescue. To maintain the genetic integrity, replication machinery needs to minimize the error rate, repair the damages, and restart the stalled replication caused by the attacks from the environment and inside the cell. The stalled replication rescue is orchestrated by a series of proteins, for example, the DNA helicases PriA and RecG and the ssDNA binding protein (SSB).

We demonstrated that SSB stimulates the restart process in two aspects. First, SSB facilitates the binding of …

Design, Synthesis And Evaluation Of Novel Inhibitors Of Type 5 And 10 17Β-Hydroxysteroid Dehydrogenases, Ahmed Morsy

Theses & Dissertations

17β-Hydroxysteroid dehydrogenases (17β-HSDs) are essential enzymes in steroid metabolism. More and more evidence points to the pivotal contributions of these enzymes in various other metabolic pathways. Therefore, the latest research results give new insights into the complex metabolic interconnectivity of the 17β-HSDs with human diseases. This dissertation focuses on the metabolic activities of type 5 and 10 17β-HSDs. More specifically, regarding 17β-HSD5 contributions to the progression of prostate cancer (PCa) and 17β-HSD10 aggravation of amyloid-beta (Aβ)-induced toxicity in Alzheimer's disease (AD).

The second leading cause of cancer-related death in males is PCa, with the highest incidence rate of all cancers …

Mucin And Splice Variant Profiles Of Pancreatic Adenocarcinoma Predict Patient Survival And Subtyping, Christopher M. Thompson

Theses & Dissertations

PDAC is a pancreatic epithelial malignancy and demonstrates aggressive progression and bleak patient prognosis. Despite decades of research, the evolution of novel diagnostics and intervention modalities for PDAC is stagnant. This dissertation explores the characteristic aberrant and elevated expression of mucins in PDAC. Beginning with the hypothesis that mucins are associated with disease aggressiveness, analysis of PDAC patient survival in TCGA revealed no associations between single mucin expression and patient survival. This led to the underlying issue of PDAC tumor cellularity since this disease demonstrates variability in the proportion of cancer cells within the tumor. Tumor purity assessed with the …

Secreted Mucin 5ac-Mediated Epithelial And Stromal Modulations Augment Pancreatic Cancer Aggressiveness, Koelina Ganguly

Theses & Dissertations

The mucosal layer that shields the epithelium of the body cavities is made up of high molecular weight, heavily glycosylated proteins called mucins that are broadly categorized into transmembrane and secreted members. Aberrant expression of secreted mucin MUC5AC has been implicated in lung, stomach, and colon cancer pathologies. MUC5AC is expressed de novo in the pancreas upon oncogenic insult, and its abundance in pancreatic tumor and circulation correlates to disease progression. However, few studies have explored beyond the diagnostic and prognostic significance of MUC5AC in pancreatic cancer (PC).

In this dissertation, we sought to investigate the mechanistic contribution of MUC5AC …

Mechanisms By Which Mnte-2-Pyp Suppresses Prostate Cancer Cell Growth, Yuxiang Zhu

Theses & Dissertations

Prostate cancer patients are often treated with radiotherapy. MnTE-2-PyP, is a superoxide dismutase (SOD) mimic and a known radioprotector of normal tissues. Our recent work demonstrates that MnTE-2-PyP also inhibits prostate cancer progression with radiotherapy; however, the mechanisms remain unclear. In this thesis, we identified that MnTE-2-PyP-induced intracellular H2O2 levels are critical in inhibiting growth of prostate cancer cells. We found that MnTE-2-PyP induced protein oxidations in PC3 cells and one major group of oxidized protein targets were involved in energy metabolism. The oxidative phosphorylation rates were significantly enhanced in both PC3 and LNCaP cells with MnTE-2-PyP treatment, but mitochondrial …

Delivery Of Small Molecule And Rna Using Synthetic Polymeric Micelles And Multifunctional Exosomes For The Treatment Of Type 1 Diabetes, Yang Peng

Theses & Dissertations

Type 1 diabetes is one of the most challenging chronic autoimmune diseases. The destruction and dysfunction of insulin-secreting β cells are the results of inflammatory infiltration and the synergistic effect of multiple immune cells. The aim of this dissertation is to develop novel and reliable therapeutic approaches to advance the treatment of T1D: including chemical modification of a broad-spectrum immunosuppressant, co-application of small molecule based immune intervention and siRNA based β cell preservative therapy, and administration of a PI3K-δ/γ dual inhibitor to specifically target immune cells, utilizing synthetic polymeric micelles or natural produced multi-functional exosomes derived from human bone marrow …

Defining The Role Of Tyrosine Phosphorylation In The Regulation Of Connexin43 In Cardiac Diseases, Li Zheng

Theses & Dissertations

Connexins are integral membrane proteins that oligomerize to form gap junction channels. Ions and small molecules diffuse intercellularly through these channels, allowing individual cellular events to synchronize into the functional response of an entire organ. Gap junction channels composed of Connexin43 (Cx43) mediate electrical coupling and impulse propagation in the normal working myocardium. In the failing heart, Cx43 remodeling (decreased expression, altered phosphorylation state, loss at intercalated discs, and increased presence at lateral membranes) contributes to rhythm disturbances and contractile dysfunction. While there is considerable information regarding key interactions of Cx43 in the regulation of gap junction channels, unfortunately, the …

Engineering Hyaluronic Acid For Biomedical Applications, Deep S. Bhattacharya

Theses & Dissertations

This work presents research using the naturally available non- sulfated carbohydrate glycosaminoglycan hyaluronic acid (HA) for the synthesis of different chemical derivatives of HA for evaluation of binding kinetics with CD44 and P- selectin proteins for applications in fluorescence image-guided surgery. Chemical derivatives of HA such as deacetylated HA (deHA), sulfated HA (sHA), and deacetylated and sulfated HA (s-deHA) were synthesized by modulating sulfating and deacetylating reagents to alter binding specificities to CD44. Modified HA derivatives and CD44 biophysical interactions were assessed by fluorescence polarization. In silico techniques were also used to determine binding using molecular docking and MM-PBSA approaches. …

The Role Of Ros In The Progression And Treatment Of Castration-Resistant Prostate Cancer, Dannah R. Miller

Theses & Dissertations

Prostate cancer is the second leading cause of cancer-related deaths in U.S. men, primarily due to the development of castration-resistant (CR) prostate cancer (PCa), of which there are no effective treatment options. Reactive oxygen species (ROS) plays a critical role in prostate carcinogenesis, including the progression of the CR PCa phenotype. ROS regulates both cell proliferation and apoptosis; a moderate increase in ROS can promote proliferation; however, a substantial rise in ROS levels will result in apoptosis. Oxidase p66Shc is elevated in clinical PCa cells and has been associated with a metastatic phenotype of CR PCa cells, promoting PCa cell …

Functional And Mechanical Role Of Splice Variant Of Mucin4 (Muc4/X) And Trefoil Factors In Pancreatic Cancer Pathogenesis, Rahat Jahan

Theses & Dissertations

Pancreatic Cancer (PC) is one of the vicious cancers as it ranks third in the race of leading cause of cancer-related death. Lack of early diagnostic marker, poor understanding of molecular mechanism of the disease and failure to conventional chemotherapy makes this disease dreadful.

Mucin 4 (MUC4), a high molecular weight glycoprotein is one of the top differentially expressed molecules in PC while not expressed in normal pancreas. Accumulating evidence from our lab suggested its tumorigenic role in PC by increasing cell proliferation, invasion, chemotherapy resistance, tumor growth, and metastasis. Previously, our lab and other has identified 24 different splice …

Muc4 Based Immunotherapy For Pancreatic Cancer, Kasturi Banerjee

Theses & Dissertations

Pancreatic Cancer (PC) is a lethal disease claiming approximately 45000 lives in the US in 2018, and it establishes an elaborate immunosuppressive tumor microenvironment that aids in disease pathogenesis. Immunotherapy has emerged as a strategy to target tumor cells by reprogramming patient’s immune system. Challenges present in PC immunotherapy are: i) identifying a tumor-associated antigen that could be targeted, ii) identifying adjuvants that could efficiently deliver antigens, iii) eliciting robust anti-tumor responses and iv) overcoming peripheral tolerance and immunosuppression elicited by the tumor.

Firstly, we detected circulating autoantibodies to MUC4 present in PC patients and observed that IgM autoantibodies to …

Elucidation Of The Functions Of Neuropilin 2 In Osteoclasts In Promoting Prostate Cancer Bone Metastasis., Navatha S. Polavaram

Theses & Dissertations

Bone metastasis is one of the major clinical concerns that causes skeletal related malignancies and increased mortality. Bone is one of the preferred sites for metastatic prostate cancer. The metastatic prostate cancer cells interact with bone cells (osteoblasts and osteoclasts) resulting in an imbalance in the bone homeostasis leading to increased activation of osteoblasts over osteoclasts. Our preliminary data indicated a non-tyrosine kinase receptor Neuropilin 2 (NRP2) is expressed in osteoclasts induced by metastatic prostate cancer cells and acts as a negative regulator of osteoclast differentiation and function. We hypothesize that prostate cancer -induced NRP2 expression in osteoclasts is necessary …

The Beta-Catenin/Muc1.Ct Interaction In Pancreatic Cancer, Edwin Wiest

Theses & Dissertations

MUC1 is overexpressed in over 90% of pancreatic cancer cases, and its interaction with beta-catenin promotes progression of the disease. Various in vitro and in vivo methods show that beta-catenin and MUC1 interact by way of the cytoplasmic tail of MUC1 (MUC1.CT). This interaction occurs in the membrane of pancreatic cancer cells but is found to a smaller extent in the nucleus as well. Biophysical methods suggest that MUC1 interacts with beta-catenin through a sequence of amino acids in the tail of MUC1 that sit very near the transmembrane domain of MUC1. In pancreatic ductal adenocarcinoma cells, it appears that …

The Rise And Fall Of The Bovine Corpus Luteum, Heather Talbott

Theses & Dissertations

This dissertation describes a study of the mechanisms regulating the genesis and subsequent involution of the temporary endocrine structure, the corpus luteum (CL), through the use of a bovine model. The CL is essential for maintaining a suitable uterine environment for embryo implantation and early development through secretion of the steroid hormone progesterone. The “Rise and Fall” of the CL occurs within each estrous cycle whereby the CL must form from the ruptured follicle, secrete sufficient progesterone for uterine maturation, and at the end of the cycle (or pregnancy) regress to allow new follicular development. During the rise of the …

Investigation Of Behavioral And Cellular Changes In The Maternal Immune Activation Model Of Autism Spectrum Disorders, Shreya Roy

Theses & Dissertations

Maternal infection during pregnancy, which leads to maternal immune activation (MIA), is an environmental risk factor for autism spectrum disorders (ASD). MIA can be induced in mice and their offspring exhibit behaviors that model the core symptoms of ASD. One of the core behavioral symptoms in ASD patients is presence of increased repetitive behavior, which is modeled by an increase in marble burying in MIA mice. It has been shown that the deficits seen in MIA mice are associated with the dysregulation of cytokine levels in the developing brain, specifically an increase in pro-inflammatory cytokines. In this thesis, I tested …