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2022

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Articles 31 - 60 of 118

Full-Text Articles in Cancer Biology

Non-Photic Mechanisms Of Entrainment In Bmal1 Deficient Conditions, Jamie Tran Aug 2022

Non-Photic Mechanisms Of Entrainment In Bmal1 Deficient Conditions, Jamie Tran

Dissertations and Theses (Open Access)

Maintaining our internal circadian (i.e. 24 -hour) clock is imperative to our daily biological and mental well-being. Large epidemiological studies have shown that disruptions of our circadian rhythms can lead to poor mental health, metabolic diseases, and various types of cancer. Various external cues that have become a part of the modern times such as electricity, shift -work, rapid travel across various time zones, easier access to nutritionally unbalanced food items, and various rigid social demands have deleterious effects on our internal clock, and generally reduce robustness of the circadian clock. The two following projects aim to examine two fundamental …


The Roles Of Epithelial–Mesenchymal Plasticity In Tumor Heterogeneity, Metastasis, And Patient Survival In Breast Cancer, Meredith Septer Brown Jul 2022

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 …


Trends In Utilization Of Human Papillomavirus Vaccines And The Incidence Of Malignant Cervical Cancer In The U.S. Population: A Secondary Analysis, Myah Luna, Soumya Upadhyay Jun 2022

Trends In Utilization Of Human Papillomavirus Vaccines And The Incidence Of Malignant Cervical Cancer In The U.S. Population: A Secondary Analysis, Myah Luna, Soumya Upadhyay

Healthcare Administration and Policy Faculty Research

Background: Human papillomavirus (HPV) is a sexually transmitted infection, and HPV types 16 and 18 are responsible for approximately 66% of all U.S. cervical cancer cases in women. The quadrivalent HPV vaccine was licensed in mid-2006, and it was designed to target and protect against HPV types 6, 11, 16, and 18. The aim of this study is to examine the utilization rate of the HPV vaccine, and the trends and incidence rate of malignant cervical cancer across the United States. Methods: This study utilized data from Surveillance, Epidemiology, and End Results (SEER) and the National Immunization Survey's (NIS) teenage …


Combined Curcumin And Luteolin Synergistically Inhibit Colon Cancer Associated With Notch1 And Tgf-Β Signaling Pathways In Cultured Cells And Xenograft Mice, Rukayat Aromokeye, Hongwei Si Jun 2022

Combined Curcumin And Luteolin Synergistically Inhibit Colon Cancer Associated With Notch1 And Tgf-Β Signaling Pathways In Cultured Cells And Xenograft Mice, Rukayat Aromokeye, Hongwei Si

Human Sciences Faculty Research

This study aimed to select a combination of curcumin and luteolin, two phytochemicals from food, at lower concentrations with a higher inhibitory effect on colon cancer growth and investigate possible molecular mechanisms of this anti-colon cancer effect. By pairwise combination screening, we identified that the combination of curcumin (CUR) at 15 μM and luteolin (LUT) at 30 μM (C15L30) synergistically suppressed the proliferation of human colon cancer CL-188 cells, but the individual chemicals had a little inhibitory effect at the selected concentrations. This result was also confirmed in other colon cancer DLD-1cells, suggesting that this synergistic inhibitory effect of C15L30 …


Complex Role Of Microbiome In Pancreatic Tumorigenesis: Potential Therapeutic Implications, Suneetha Amara, Li V. Yang, Venkataswarup Tiriveedhi, Mahvish Muzaffar Jun 2022

Complex Role Of Microbiome In Pancreatic Tumorigenesis: Potential Therapeutic Implications, Suneetha Amara, Li V. Yang, Venkataswarup Tiriveedhi, Mahvish Muzaffar

Biology Faculty Research

Pancreatic cancer (PC) is the fourth leading cause of cancer-related mortality with limited diagnostic and therapeutic options. Although immunotherapy has shown promise in the treatment of several cancers, its role in pancreatic cancer is rather limited. Several studies have focused on determining the role of the tumor microenvironment with cancer-cell-intrinsic events and tumor-infiltrating immune cellular properties. However, in the past decade, there has been emerging research aimed at delineating the role of the host microbiome, including the metabolites from microbes and host responses, on pancreatic tumorigenesis. Importantly, there is emerging evidence suggesting the beneficial role of a gut microbiome transplant …


Low-Salt Diet Reduces Anti-Ctla4 Mediated Systemic Immune-Related Adverse Events While Retaining Therapeutic Efficacy Against Breast Cancer, Durga Khandekar, Debolanle O. Dahunsi, Isaac V. Manzanera Esteve, Sonya Reid, Jeffrey C. Rathmell, Jens M. Titze, Venkataswarup Tiriveedhi May 2022

Low-Salt Diet Reduces Anti-Ctla4 Mediated Systemic Immune-Related Adverse Events While Retaining Therapeutic Efficacy Against Breast Cancer, Durga Khandekar, Debolanle O. Dahunsi, Isaac V. Manzanera Esteve, Sonya Reid, Jeffrey C. Rathmell, Jens M. Titze, Venkataswarup Tiriveedhi

Biology Faculty Research

Immune checkpoint inhibitor (ICI) therapy has revolutionized the breast cancer treatment landscape. However, ICI-induced systemic inflammatory immune-related adverse events (irAE) remain a major clinical challenge. Previous studies in our laboratory and others have demonstrated that a high-salt (HS) diet induces inflammatory activation of CD4+T cells leading to anti-tumor responses. In our current communication, we analyzed the impact of dietary salt modification on therapeutic and systemic outcomes in breast-tumor-bearing mice following anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4) monoclonal antibody (mAb) based ICI therapy. As HS diet and anti-CTLA4 mAb both exert pro-inflammatory activation of CD4+T cells, we hypothesized that a combination of …


Cytotoxic Activity Of Non-Specific Lipid Transfer Protein (Nsltp1) From Ajwain (Trachyspermum Ammi) Seeds, Saud O. Alshammari, Taibah Aldakhil, Qamar A. Alshammari, David Salehi, Aftab Ahmed May 2022

Cytotoxic Activity Of Non-Specific Lipid Transfer Protein (Nsltp1) From Ajwain (Trachyspermum Ammi) Seeds, Saud O. Alshammari, Taibah Aldakhil, Qamar A. Alshammari, David Salehi, Aftab Ahmed

Pharmacy Faculty Articles and Research

Background

Trachyspermum ammi, commonly known as Ajwain, is a member of the Apiaceae family. It is a therapeutic herbal spice with diverse pharmacological properties, used in traditional medicine for various ailments. However, all previous studies were conducted using small molecule extracts, leaving the protein’s bioactivity undiscovered.

Aim

The current study aimed to demonstrate the cytotoxic activity of Ajwain non-specific lipid transfer protein (nsLTP1) in normal breast (MCF10A), breast cancer (MCF-7), and pancreatic cancer (AsPC-1) cell lines. Also, to evaluate its structural stability in human serum as well as at high temperature conditions.

Methods

The cytotoxic activity of Ajwain nsLTP1 was …


Microbial Experience Increases Cytotoxicity Of Tumor-Infiltrating Cd8+ T Cells And Controls Tumor Growth, Nicholas Aaron Bunda May 2022

Microbial Experience Increases Cytotoxicity Of Tumor-Infiltrating Cd8+ T Cells And Controls Tumor Growth, Nicholas Aaron Bunda

Masters Theses

Cancer immunotherapy research is traditionally conducted with specific pathogen-free (SPF) mice, which most accurately mimic the immune system of a human newborn. This makes translational research challenging, as this mouse model is not an accurate reflection of the adult patients who ultimately receive newly developed treatments. It is necessary to further develop a mouse model that bridges this gap and increases translatability of current cancer immunotherapy research.

By cohousing specific pathogen-free mice with regular pet store (PS) mice, we have generated a cohoused (CoH) mouse that reflects the microbial experience of an adult human immune system. We investigated antigen experience, …


Activation Of P53-Regulated Pro-Survival Signals And Hypoxia-Independent Mitochondrial Targeting Of Tigar By E6 Oncoproteins Of High-Risk Hpvs, Lacin Yapindi May 2022

Activation Of P53-Regulated Pro-Survival Signals And Hypoxia-Independent Mitochondrial Targeting Of Tigar By E6 Oncoproteins Of High-Risk Hpvs, Lacin Yapindi

Biological Sciences Theses and Dissertations

The high-risk human papillomaviruses are small, non-enveloped double-stranded DNA viruses that infect the basal epithelial keratinocytes. The majority of HPV infections are self-limiting and asymptomatic; however, in 2-4% of all infected individuals, persistent infections with high-risk HPVs lead to malignancies, including head-and-neck cancers and anogenital carcinomas, particularly cervical cancers. The HPV life cycle is strongly tied to the normal differentiation process of the epithelial tissue. Upon cell entry, the viral genome is maintained as episomal DNA within the nuclei of HPV-infected basal keratinocytes and amplified to a low copy number as the cells divide. As a part of the self-renewing …


A Small Peptide Increases Drug Delivery In Human Melanoma Cells, Shirley Tong, Shaban Darwish, Hanieh Hossein Nejad Ariani, Kate Alison Lozada, David Salehi, Maris A. Cinelli, Richard B. Silverman, Kamaljit Kaur, Sun Yang May 2022

A Small Peptide Increases Drug Delivery In Human Melanoma Cells, Shirley Tong, Shaban Darwish, Hanieh Hossein Nejad Ariani, Kate Alison Lozada, David Salehi, Maris A. Cinelli, Richard B. Silverman, Kamaljit Kaur, Sun Yang

Pharmacy Faculty Articles and Research

Melanoma is the most fatal type of skin cancer and is notoriously resistant to chemotherapies. The response of melanoma to current treatments is difficult to predict. To combat these challenges, in this study, we utilize a small peptide to increase drug delivery to melanoma cells. A peptide library array was designed and screened using a peptide array-whole cell binding assay, which identified KK-11 as a novel human melanoma-targeting peptide. The peptide and its D-amino acid substituted analogue (VPWxEPAYQrFL or D-aa KK-11) were synthesized via a solid-phase strategy. Further studies using FITC-labeled KK-11 demonstrated dose-dependent uptake in human melanoma cells. D-aa …


Targeting Androgen Receptor On Glioblastoma, Nan Zhao May 2022

Targeting Androgen Receptor On Glioblastoma, Nan Zhao

Theses & Dissertations

Glioblastoma (GBM) is the most aggressive primary brain malignancy. The standard treatment of this tumor is surgery, followed by radiation with concurrent and adjuvant temozolomide. GBM cancer stem cells (CSCs) have been proposed to be responsible for radioresistance. It is necessary to identify novel therapeutic agent(s) that can pass the blood-brain barrier (BBB) and enhance radiation effects. Targeting the androgen receptor (AR) is promising in treating glioblastoma (GBM) in cell culture, and flank implant models but the mechanisms remain unclear. AR antagonists, including enzalutamide, are available for treating prostate cancer patients in the clinic and can pass the BBB; thus, …


Visceral Adipose Tissue Remodeling In Pancreatic Ductal Adenocarcinoma Cachexia: The Role Of Activin A Signaling, Pauline Xu May 2022

Visceral Adipose Tissue Remodeling In Pancreatic Ductal Adenocarcinoma Cachexia: The Role Of Activin A Signaling, Pauline Xu

Theses & Dissertations

Pancreatic ductal adenocarcinoma (PDAC) is currently the third leading cause of cancer death in the United States and is projected to become the second leading cause by the year 2030. Prognosis for patients with metastatic disease remains dismal, with cachexia as a main contributor to the low survival rate. Emerging reports indicate that PDAC patients display distinct phenotypes of cachexia development, with either adipose tissue loss preceding skeletal muscle wasting or loss of only adipose tissue. While muscle wasting has been the most frequently studied mechanism in cachexia research, changes in adipose tissue are increasingly understood as important components of …


Evaluating Targets And Therapeutics For The Treatment Of Pancreatic Cancer, Shelby M. Knoche May 2022

Evaluating Targets And Therapeutics For The Treatment Of Pancreatic Cancer, Shelby M. Knoche

Theses & Dissertations

Pancreatic cancer has a dismally low survival rate, due to inadequate understanding of the processes that are involved in disease development and progression. Despite the identification of oncogenic drivers such as KRAS and p53, there is a need for the identification of molecular targets to improve and develop novel therapeutic approaches for the treatment of pancreatic cancer. Studies from our laboratory have identified and evaluated targets and therapeutic approaches that can aid in our understanding of pancreatic cancer disease progression and improve patient outcomes. Through the use of epidermal growth factor receptor (EGFR) ligands (EGF and TGF-α) and small molecule …


Phos-Tag-Based Screens Identify Novel Therapeutic Targets In Ovarian Cancer And Pancreatic Cancer, Renya Zeng May 2022

Phos-Tag-Based Screens Identify Novel Therapeutic Targets In Ovarian Cancer And Pancreatic Cancer, Renya Zeng

Theses & Dissertations

Multiple Phos-tag-based screens were conducted in anti-tubulin drug (paclitaxel and nocodazole)-treated cells to explore novel targets implicated in cell cycle regulation, resistance against paclitaxel, and yes-associated protein (YAP) nucleocytoplasmic transport. The Phos-tag-based screen of protein kinases identified that several proteins were degraded or phosphorylated in response to anti-tubulin drug treatment. A tyrosine kinase, fibroblast growth factor receptor 4 (FGFR4), was significantly degraded upon anti-tubulin drug treatment, suggesting its potential role in cell response to paclitaxel. Further functional investigations identified that FGFR4 mediated paclitaxel resistance in ovarian cancer, and specific inhibitors targeting FGFR4 could sensitize ovarian cancer cells to paclitaxel. Mechanistically, …


Characterization Of 1,1-Diarylethylene Foxm1 Inhibitors Against High-Grade Serous Ovarian Carcinoma Cells, Cassie Liu May 2022

Characterization Of 1,1-Diarylethylene Foxm1 Inhibitors Against High-Grade Serous Ovarian Carcinoma Cells, Cassie Liu

Theses & Dissertations

Forkhead box M1 (FOXM1) is a member of the conserved forkhead box (FOX) transcription factor family. Over the last two decades, FOXM1 has emerged as a multifunctional oncoprotein and a robust biomarker of poor prognosis in many human malignancies. FOXM1 and its associated oncogenic transcriptional signature are enriched in >85% of ovarian cancer cases, and FOXM1 expression and activity can be enhanced by a plethora of genomic, transcriptional, post-transcriptional, and post-translational mechanisms. As a master transcriptional regulator, FOXM1 promotes critical oncogenic phenotypes in ovarian cancer, including: (1) cell proliferation, (2) invasion and metastasis, (3) chemotherapy resistance, (4) cancer stem cell …


Sox2 Dosage Governs Tumor Cell Identity And Proliferation, Ethan P. Metz May 2022

Sox2 Dosage Governs Tumor Cell Identity And Proliferation, Ethan P. Metz

Theses & Dissertations

The stem cell transcription factor SOX2 has been widely recognized for its critical roles during mammalian development. SOX2 expression has also been implicated in more than 20 types of human cancers. Importantly, the expression of SOX2 is regulated at multiple levels, which enables the tight regulation of SOX2 levels. Previous work from our laboratory has shown that elevating SOX2 from an inducible promoter inhibits the proliferation of several human tumor cell types. Other studies have reported that high levels of SOX2 are necessary to maintain lineage plasticity in advanced tumors. Thus, the dosage of SOX2 plays a critical role in …


Use Of Machine Learning Algorithms And Highly Multiplexed Immunohistochemistry To Perform In-Depth Characterization Of Primary Pancreatic Tumors And Metastatic Sites, Krysten Vance May 2022

Use Of Machine Learning Algorithms And Highly Multiplexed Immunohistochemistry To Perform In-Depth Characterization Of Primary Pancreatic Tumors And Metastatic Sites, Krysten Vance

Theses & Dissertations

Pancreatic cancer is currently the third leading cause of cancer death and projected to be the second by 2030. Metastatic pancreatic cancer, the most common form of the disease, has a dismal 3% five-year survival rate. However, understanding of the metastatic disease and particularly the metastatic tumor microenvironment (TME), which includes all non-cancerous cells in and around the tumor, has remained limited. The well-documented impact of the TME on cancer cell proliferation, chemoresistance, and patient survival in the primary tumors, indicates that the study of the microenvironment in metastatic cancer is integral to treating advanced patients. To better comprehend this …


Plant Based Polyphenols Decrease Cell Migration And Inhibit Proliferation Of Human Pancreatic Cancer Cells, Mary Gathoni May 2022

Plant Based Polyphenols Decrease Cell Migration And Inhibit Proliferation Of Human Pancreatic Cancer Cells, Mary Gathoni

Electronic Theses & Dissertations

Pancreatic cancer is one of the most highly malignant tumors of the digestive tract. Both the incidence and death rate of pancreatic cancer have increased since 2000. The disease has a poor prognosis with a relative 5-year survival rate of 10%. Pancreatic cancer-related mortality can be mainly attributed to lack of early diagnosis, tumor metastasis, lack of effective treatment strategies and drug resistance. There has been a mounting interest on the use of plant-based compounds such as polyphenols in cancer treatment therapies. This is mainly due to their low toxicity and fewer side effects compared to the conventional chemotherapeutic options …


Sequential Illumination In A Tomographic Microendoscopic Probe For Imaging Tumor Microvasculature, Zachariah Neumeier May 2022

Sequential Illumination In A Tomographic Microendoscopic Probe For Imaging Tumor Microvasculature, Zachariah Neumeier

Biomedical Engineering Undergraduate Honors Theses

Knowledge of colorectal cancer biology is improving how we approach cancer treatment. Specifically, the tumor microenvironment and abnormal angiogenesis are of particular interest. Optical methods are a prime candidate for research of the tumor microenvironment due to their ability to quantitively assess tissue structure and perfusion in real time. Particularly, the “transport scattering regime” has been identified as a method of obtaining high-resolution images and reflectance spectroscopy data; this light scattering regime has been demonstrated compatible with endoscopic imaging systems. In this study, a proof-of-concept optical imaging system is presented, capable of resolving absorbers within scattering turbid media using a …


Colorectal Cancer Screening In The Latino Population At A Family Medicine Clinic: A Quality Improvement Project, Michael S. Vinson May 2022

Colorectal Cancer Screening In The Latino Population At A Family Medicine Clinic: A Quality Improvement Project, Michael S. Vinson

The Eleanor Mann School of Nursing DNP Capstone Projects

Background: Colorectal cancer (CRC) is a preventable and curable disease that affects all genders, races, and ethnicities, and its impact on society can be reduced with early screening. The Latino population is at greater risk compared to groups or ethnicities due to social determinants and health disparities within the community. Review of Literature: Language barriers, low education levels, persistent social stressors, poor healthcare navigation, and structural barriers make it difficult for this population to be properly screened at appropriate intervals. Purpose: This quality improvement (QI) project was designed to combat reduced screening rates seen in the Latino population. The target …


Headcase Regulates Growth In Response To Nutritional Status Downstream Of Insulin Signaling, Thomas George May 2022

Headcase Regulates Growth In Response To Nutritional Status Downstream Of Insulin Signaling, Thomas George

Honors Scholar Theses

Cancer cells are notorious for growing in an unrestricted manner without regard for environmental cues. Recently, Li et al. (2019) discovered headcase (hdc) functions by binding to the mTORC1 complex in the mTOR signaling pathway and preventing further signaling. Interestingly, under nutrient restricted (NR) conditions, cells with mutated hdc proteins proliferated more than cells with normal functioning hdc. It is well known that insulin signaling is downregulated under NR conditions, so a potential signaling pathway with insulin, PI3K, PDK1, Akt, PTEN, and hdc was created as a way to explain the link between hdc function and nutritional status. A Drosophila …


Investigating The Impact Of Hypoxia On Reactive Oxygen Species Generation Within Murine Breast Cancer Cells, Jared Mcpeake May 2022

Investigating The Impact Of Hypoxia On Reactive Oxygen Species Generation Within Murine Breast Cancer Cells, Jared Mcpeake

Biomedical Engineering Undergraduate Honors Theses

When cancer metastasizes from a primary tumor site to secondary site through the bloodstream or lymph, the cancer becomes more difficult to treat. For this reason, it is vital to study what indicates the metastatic potential of a tumor. Current research has shown that cell lines with high metastatic potential display increased levels of metabolic adaptability over their nonmetastatic counterparts after undergoing hypoxic conditions. One method of assessing this adaptability is to measure the concentration of reactive oxygen species (ROS) produced by the cells while undergoing oxidative stress. In highly adaptable metastatic cells, an increase of ROS buildup within the …


Investigation Of Microbe And Host Tissue Interactions Contributing To The Pathogenesis Of Colorectal Cancer, Ryan Chapman, Dhundy Bastola May 2022

Investigation Of Microbe And Host Tissue Interactions Contributing To The Pathogenesis Of Colorectal Cancer, Ryan Chapman, Dhundy Bastola

Theses/Capstones/Creative Projects

Colorectal cancer (CRC) is one of the leading causes of cancer-related death worldwide. The pathogenesis of this disease can fall under broad categories; however, the specific precursory mechanism of CRC pathogenesis is still unknown. Dysregulations of the gut microbiome have been identified in the CRC tissue environment. Additionally, CRC tissue gene expression has been observed to differ from that of healthy tissue. Despite these noticeable changes, few studies have directly compared the microorganism composition to the gene expression of CRC tissue. Doing so may identify whether the differentially abundant microorganisms influence the changes in gene expression. The goal of this …


Novel Regulators Of Cellular Secretion Alter The Tumor Microenvironment To Drive Metastasis, Rakhee Bajaj May 2022

Novel Regulators Of Cellular Secretion Alter The Tumor Microenvironment To Drive Metastasis, Rakhee Bajaj

Dissertations and Theses (Open Access)

Lung cancer is a highly aggressive disease responsible for ~25% of all cancer-related deaths, due in part to its proclivity to metastasize. Treating metastasis holds potential for improving patient survival but requires a deeper investigation into the underlying mechanisms. Some of these processes that can regulate metastasis are: (1) Oncogenic targets of epithelial micro-RNAs (miRNAs) are epigenetically de-repressed upon loss of the miRNAs during epithelial-to-mesenchymal transition (EMT) and in cancer. EMT confers plasticity and fitness to cancer cells promoting their survival through the metastatic cascade. This cascade and EMT are initiated by loss of the miRNA200 family (miR-200) and the …


The Effects Of Metronomic And Maximum-Tolerated Dose Chemotherapy In Colorectal Cancer Angiogenesis: A Combined Approach Using Endoscopic Diffuse Reflectance Spectroscopy And Mrna Expression, Ariel Isaac Mundo Ortiz May 2022

The Effects Of Metronomic And Maximum-Tolerated Dose Chemotherapy In Colorectal Cancer Angiogenesis: A Combined Approach Using Endoscopic Diffuse Reflectance Spectroscopy And Mrna Expression, Ariel Isaac Mundo Ortiz

Graduate Theses and Dissertations

Colorectal cancer (CRC) continues to be one of the most incident and deadliest types of cancer worldwide. Chemotherapy has proven effective to reduce tumor burden for CRC patients, but there are several disadvantages associated with the use of mainstay maximtolerated dose (MTD) chemotherapeutic strategies. Metronomic chemotherapy (MET) has been developed as an alternative that addresses the shortcomings of maximum-tolerated dose chemotherapy but so far its effectiveness as a neoadjuvant strategy for CRC has not been explored.

This dissertation uses a combined optics and molecular biology approach (using diffuse reflectance spectroscopy and mRNA expression) to study the changes in angiogenesis and …


Characterization Of The Influence Of A Small Molecule Inhibitor On Ras-Related Proteins Interactions, Emilio Duverna May 2022

Characterization Of The Influence Of A Small Molecule Inhibitor On Ras-Related Proteins Interactions, Emilio Duverna

Graduate Theses and Dissertations

The Ras superfamily of small G proteins are involved in cell-signaling processes that, if not regulated, may lead to cell multiplication, apoptosis inhibition, and tumorigenesis. They function as molecular switches, which through GTP/GDP exchange cycle, switch on or off cellular activities. Overexpression and/or hyperactivity of these proteins have been linked to many diseases including various cancers. CDC42, a member of the Rho subfamily of the Ras superfamily of small G proteins, participates in the regulation of many cellular processes including cell adhesion, mitosis, and cytoskeletal rearrangements. CDC42 binds to and activates many effector proteins including CDC42-activated kinase (ACK). Abnormal activities …


The Roles Of Pon2 In Mitochondrial Physiology, Lung Tumor Cell Proliferation, And Lung Tumorigenesis., Aaron Whitt May 2022

The Roles Of Pon2 In Mitochondrial Physiology, Lung Tumor Cell Proliferation, And Lung Tumorigenesis., Aaron Whitt

Electronic Theses and Dissertations

Paraoxonase 2 (PON2) is an intracellular, multifunctional enzyme with near-ubiquitous tissue distribution. Within cells, PON2 is localized to mitochondria and endoplasmic reticulum (ER), where it mitigates the formation of reactive oxygen species (ROS). PON2’s chief enzymatic function is its lactonase activity, through which it catalyzes the hydrolysis of a bacterial quorum-sensing molecule, N-(3-oxododecanoyl)-l-homoserine lactone (C12), effectively disrupting bacterial intercellular communication and protecting against infection. C12 is produced by the opportunistic pathogen Pseudomonas aeruginosa and has been shown to disrupt various aspects of eukaryotic host cell physiology and evoke apoptotic cell death through the activity of PON2. Additionally, PON2 has garnered …


Exploiting Chemogenetic And Genetic Interactions In Human Cells As An Avenue For New Therapeutic Opportunities, Medina Colic May 2022

Exploiting Chemogenetic And Genetic Interactions In Human Cells As An Avenue For New Therapeutic Opportunities, Medina Colic

Dissertations and Theses (Open Access)

The advent of CRISPR technology and its adaptation to the mammalian genome made whole-genome knockout screens possible directly in human cells. Gene knockout answers how essential that gene is for cell fitness and proliferation. Genes showing moderate to severe fitness defects are called essential genes and provide insights into disease-specific candidate therapeutic targets. Additionally, CRISPR offers other applications for genome editing. Two applications this dissertation is based on are 1) combination of gene knockout and drug treatment, which enables the identification of chemogenetic interactions, or gene mutations that enhance or suppress the activity of a drug, and 2) combinatorial editing, …


An Investigation Of Epigenetic Mechanisms Driving The Biology Of Head And Neck Squamous Cell Carcinoma, Scot Carson Callahan May 2022

An Investigation Of Epigenetic Mechanisms Driving The Biology Of Head And Neck Squamous Cell Carcinoma, Scot Carson Callahan

Dissertations and Theses (Open Access)

Head and neck squamous cell carcinoma (HNSCC) is the 6th most common cancer worldwide and is associated with significant morbidity and mortality. To date, the majority of work in the field has focused on genomic alterations such as mutations and copy number alterations. However, the clinical success of targeted therapies that exploit known genomic alterations, such as EGFR mutations, has remained mixed. Over the past decade, the importance of epigenetic regulators has come to the forefront, with the realization that many of these genes are mutated in cancer. Despite this realization, the role of epigenetics in regulating tumorigenesis, progression and …


Modulation Of Kras Structure And Dynamics By Kras Ubiquitination And Membrane Depolarization, Vinay Nair May 2022

Modulation Of Kras Structure And Dynamics By Kras Ubiquitination And Membrane Depolarization, Vinay Nair

Dissertations and Theses (Open Access)

KRAS, a 21 kDa small GTPase protein, functions as a molecular switch playing a key role in regulating cell proliferation. Dysregulation of KRAS signaling by oncogenic mutations leads to uncontrolled cell proliferation, a hallmark of cancer cells. Attempts to therapeutically target oncogenic KRAS have led to limited success resulting in a need to identify new mechanisms to targeting KRAS. The interaction of KRAS with its regulators, effectors, and the membrane present one such avenue. In this study, we investigated how post-translational covalent and environmental modifications could modulate these interactions of KRAS. Using computational molecular dynamics simulations, nuclear magnetic resonance spectroscopy …