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The Kras/Mapk Pathway And Ligand Independent Activation Of Erα: Implications For The Treatment Of Endometrial Cancer, Kari Ring

Dissertations and Theses (Open Access)

Hormonal therapy remains a first line option for the treatment of recurrent endometrial cancer (EC), however, many tumors demonstrate de novo or acquired resistance. Member kinases of the PI3K/AKT and Ras/MAPK pathways activate estrogen receptor α (ERα) independent of estrogen, however, few studies have evaluated the role of the Ras/MAPK pathway in predicting response to hormonal therapy in EC. The aims of this project were to evaluate the role of ligand independent activation of ERα in EC and to explore therapeutic implications for the treatment of recurrent EC.

A xenograft model for recurrent EC was used to evaluate the effect …

Role Of Macrophages In Adaptive Resistance To Anti-Vegf Therapy, Heather Dalton

Dissertations and Theses (Open Access)

Background: The clinical implementation of therapies targeting the VEGF pathway in cancer has been limited by acquired resistance; yet, the mechanisms by which this occurs is unclear. We investigated the role of macrophages in the development of acquired resistance to anti-VEGF antibody (AVA) therapy.

Materials and Methods: We first established a murine ovarian cancer model of resistance to anti-VEGF therapy. Using this model we investigated changes in macrophage infiltration during AVA sensitive and resistant phases. We also investigated the in vivo effects of macrophage depletion at the emergence of anti-VEGF resistance and in upfront combination with AVA therapy. In vitro …

Multiple Myeloma And Its Treatment Alter Peripheral Nervous System Structure And Function, Alyssa K. Kosturakis

Dissertations and Theses (Open Access)

MULTIPLE MYELOMA AND ITS TREATMENT ALTER PERIPHERAL NERVOUS SYSTEM STRUCTURE AND FUNCTION

Alyssa Katarina Kosturakis, BA

Supervisory Professor: Patrick M. Dougherty, PhD

Peripheral neuropathy is among the most deleterious side effects of frontline chemotherapeutics used to treat prevalent cancers. Chemotherapy-induced peripheral neuropathy (CIPN) refers to the collection of symptoms (e.g. pain, paresthesias and dysesthesias) that develop in distal, glabrous (non-hairy) skin of 20 to 100% of patients treated with chemotherapy. Peripheral neuropathy negatively impacts quality of life in cancer patients and survivors, is refractory to treatment, and is the impetus for dose-reduction and/or cessation of chemotherapy, thereby limiting treatment. Proteasome …

Regulators Of Bacterial Cell Division: Investigations Of Min Oscillation And Ftsa Activity, Jennifer R. Herricks

Dissertations and Theses (Open Access)

Cytokinesis is a fundamental process that is essential for bacterial proliferation. The cytokinetic machinery in bacteria is termed the “divisome”. The divisome is a complex of proteins that forms a ring at midcell over dividing nucleoids. In order for daughter cells to form, the divisome must constrict. As constriction occurs, two new cell poles are formed, one for each daughter cell. The first step in divisome formation is the assembly of FtsZ into a Z ring. The work presented in this dissertation focuses on two proteins that regulate the Z ring: MinD, which is a part of the Min system …

Potential Roles Of Peroxidases In Caenorhabditis Elegans Innate Immunity, George R. Tiller, George R. Tiller

Dissertations and Theses (Open Access)

The production of ROS (reactive oxygen species) in response to pathogen detection is a rapid, nonspecific response that is evolutionarily conserved from nematodes to humans. ROS serve as direct and indirect effectors of innate and adaptive immunity. In Caenorhabditis elegans, a ROS burst is observed during infection and is mediated by the dual oxidase BLI-3, which produces H₂O₂. RNAi (RNA interference) to reduce the amount of BLI-3 results in a significant increase in susceptibility to pathogens, suggesting BLI-3 has a role in the immune response. However, H₂O₂ by itself is not a …

Genetic Predictors Of Metabolic Side Effects Of Diuretic Therapy, Jorge L. Del Aguila

Dissertations and Theses (Open Access)

Thiazide diuretics are a recommended first-line monotherapy for hypertension (i.e.SBP>140 mmHg or DBP>90 mmHg). Even so, diuretics are associated with adverse metabolic side effects, such as hyperlipidemia, hyperglycemia and hypokalemia which increase the risk of developing type II diabetes. This thesis used three analytical strategies to identify and quantify genetic factors that contribute to the development of adverse metabolic effects due to thiazide diuretic treatment. I performed a genome-wide association study (GWAS) and meta-analysis of the change in fasting plasma glucose and triglycerides in response to HCTZ from two different clinical trials: the Pharmacogenomic Evaluation of Antihypertensive Responses …

Targeting The Redox System To Overcome Mechanisms Of Drug Resistance In Chronic Lymphocytic Leukemia, Marcia A. Ogasawara

Dissertations and Theses (Open Access)

Chronic Lymphocytic Leukemia (CLL) is the most common form of leukemia diagnosed in Western countries and is characterized by clonal expansion of B cells. The clinical course of CLL is diverse and nearly 50% of patients present with chromosomal abnormalities. Deletion of the short arm on chromosome 17 (del17p) occurs in 5-7% of cases and presents with the shortest median survival time and often respond poorly to therapy. The tumor suppressor gene, TP53 is located on this region and it is well established that the p53 protein regulates multiple functions including: mitochondria biogenesis, response to DNA damage and redox balance. …

Development Of Chimeric Type Iv Secretion Systems For Transfer Of Heterologous Substrates Across The Gram-Negative Cell Envelope, Trista M. Berry

Dissertations and Theses (Open Access)

Many bacteria use Type IV Secretion Systems (T4SSs) to aid in pathogenesis by translocating virulence factors across the cell envelope and into eukaryotic cells. These systems are structurally and functionally diverse, but are often compared to the archetypal VirB/VirD4 T4SS of Agrobacterium tumefaciens. This system is composed of the VirD4 type IV coupling protein (T4CP) and 11 VirB subunits (VirB1-11) that assemble as the secretion channel and an extracellular pilus. The T4CP is an inner membrane ATPase that interacts with T4SS substrates and the secretion channel, and is thought to link substrates with the secretion channel and possibly energize …

The Role Of The C5a Receptor In Host Defense Against Listeria Monocytogenes, Daniel Calame

Dissertations and Theses (Open Access)

Listeria monocytogenes (Lm) is a major cause of mortality resulting from food poisoning in the United States. While the complement component C5 is known to be protective in listeriosis, it is unknown how its cleavage fragment C5a participates. Here we show in a model of systemic Lm infection that the C5a receptor is essential for host defense. C5aR-/- mice have reduced survival and increased bacterial burden in the liver and spleen in comparison to WT mice. Surprisingly, C5aR-/- mice also have a dramatic reduction in splenocyte numbers resulting from elevated cell death as indicated by TUNEL staining and caspase 3 …

Mechanisms Of Astrocyte Contribution To Bortezomib-Induced Peripheral Neuropathy, Caleb R. Robinson

Dissertations and Theses (Open Access)

Bortezomib is a proteasome inhibitor used in the treatment of multiple myeloma and other non-solid malignancies, alone or in combination with other chemotherapy drugs. Like other chemotherapeutic agents, bortezomib treatment is frequently accompanied by chemotherapy-induced peripheral neuropathy (CIPN) that may be dose-limiting, adversely affecting quality of life and prognosis. The mechanisms behind bortezomib-induced peripheral neuropathy (BIPN) and CIPN overall are largely unknown. Recent findings in other pain models have indicated substantial involvement of glial cells in chronic pain. Although injury models have shown activation of both astrocytes and microglia following insult, research in other CIPN models has shown astrocytic activation …

Dissecting The Roles Of Trim24 In Regulation Of Hepatic Lipid Metabolism And Inflammation, Lindsey C. Minter

Dissertations and Theses (Open Access)

DISSECTING THE ROLES OF TRIM24 IN REGULATION OF HEPATIC LIPID

METABOLISM AND INFLAMMATION

Lindsey Cauthen Minter, B.S., B.A.

Advisory Professor: Michelle C. Barton, Ph.D.

In this dissertation, I report the characterization of a new mouse model that recapitulates development of hepatocellular carcinoma (HCC) following spontaneous hepatic lipid accumulation, inflammation, and damage of liver tissue, due to complete loss of Trim24 expression. In human HCC and other cancers, TRIM24 expression is aberrantly high, while deletion of TRIM24 in the mouse has been shown to act as a liver specific tumor suppressor. The hypothesis tested here was that TRIM24, the E3 ubiquitin …

Development And Implementation Of An Anthropomorphic Pediatric Spine Phantom For The Assessment Of Craniospinal Irradiation Procedures In Proton Therapy, Dana Lewis

Dissertations and Theses (Open Access)

Proton therapy is gaining acceptance as a cancer treatment modality, as it allows for dose deposition to the target volume while sparing the surrounding healthy tissue. This technique is advantageous for craniospinal pediatric patients, as it reduces the radiation side effects that can occur. The purpose of this study is to design an anthropomorphic pediatric spine phantom for use in the evaluation of proton therapy facilities for clinical trial participation by the Imaging and Radiation Oncology Core (IROC) Houston QA Center. It was hypothesized that the designed phantom would evaluate patient simulation, treatment planning and delivery, assuring agreement between the …

Targeting Sequence And Function-Dependence Of Subcellular Localization Of Transient Receptor Potential Mucolipin Channels And Characterization Of Engineered Molecule Probes For Detecting Lysosomal Calcium Release, Jian Xiong

Dissertations and Theses (Open Access)

Both TRPML1 and TRPML3 are members of the mucolipin subfamily of Transient Receptor Potential (TRP) channels. They have been implicated in endolysosomal functions such as divalent cation release, luminal pH regulation, autophagy and vesicle trafficking. Interestingly, whereas TRPML1 is almost extensively localized in lysosomes, TRPML3 is typically found in both lysosomes and the plasma membrane (PM). It has been shown that TRPML3 localization depends on TRPML1, but the mechanism remains unknown. Recently, a number of TRPML1 mutants have been reported to be either retained in the endoplasmic reticulum (ER) or preferentially targeted to the PM. Coexpressing these mutants with either …

The Role Of Glutamine And Mevalonate Pathway In Affecting The Stemness And Viability Of Glioblastoma Stem Cells, Naima Hammoudi

Dissertations and Theses (Open Access)

Glioblastoma (GBM) remains the deadliest form of brain tumors. The poor prognosis of glioblastoma patients is associated with a high rate of relapse after therapy. It has been suggested that the presence of cancer stem cells, which are relatively resistant to radiation and chemotherapy, may play a significant role in the recurrence of brain tumor. Understanding the biological property of glioblastoma stem cells is important to develop effective therapeutic strategies for glioblastoma. In vitro, glioblastoma stem cells cultured in serum-free medium form self-renewing neurospheres, express the neural stem marker CD133, and are highly tumorigenic. On the other hand, in the …

Stochastic Data Assimilation Approaches For Magnetic Resonance Temperature Imaging, Joshua P. Yung

Dissertations and Theses (Open Access)

During magnetic resonance (MR)-guided thermal therapies, proton resonance frequency shift (PRFS) based MR temperature imaging can quantitatively monitor tissue temperature changes. It is widely known that the PRFS technique is easily perturbed by tissue motion, tissue susceptibility changes, magnetic field drift, and modality–dependent applicator induced artifacts. Due to recent advances in computational algorithms and hardware, much more powerful statistical analysis methods are becoming realizable in the real-time processing environment. To this end, my dissertation research focused on the development, validation, and implementation of stochastic data-driven processing techniques to increase the robustness of MR temperature monitoring during thermal therapies. MR temperature …

Energy Stress Causes Chaperones To Assemble Into Cytoplasmic Complexes, Kimberly J. Cope

Dissertations and Theses (Open Access)

The majority of proteins require molecular chaperones to assist their folding into tertiary and quaternary structures. Certain stresses can compromise the weak hydrophobic forces responsible for these structures and lead to protein unfolding, misfolding, and aggregation. Aggregates of proteins are hallmarks of devastating diseases such as Alzheimer’s, Parkinson’s, and Huntington’s diseases. Fortunately, bacteria, plants, and fungi have a potent disaggregase, named Hsp104 in Saccharomyces cerevisiae. Recently, heat-induced aggregates, termed Q-bodies, were found to contain three molecular chaperones: Hsp70, Hsp104, and Hsp42. Their coalescence from small puncta into larger inclusions required Hsp104. During glucose deprivation, a stress that isn’t known to …

Global Burden Of Disease Study 2010: Interpretation And Implications For The Neglected Tropical Diseases, Peter J. Hotez, Miriam Alvarado, Maria Gloria Basanez, Ian Bolliger, Et Al.

Faculty, Staff and Students Publications

No abstract provided.

Pattern Of Mutation Rates In The Germline Of Drosophila Melanogaster Males From A Large-Scale Mutation Screening Experiment, Jian-Jun Gao, Xue-Rong Pan, Jing Hu, Li Ma, Jian-Min Wu, Ye-Lin Shao, Shi-Meng Ai, Shu-Qun Liu, Sara A Barton, Ronny C Woodruff, Ya-Ping Zhang, Yun-Xin Fu

Faculty, Staff and Student Publications

The sperm or eggs of sexual organisms go through a series of cell divisions from the fertilized egg; mutations can occur at each division. Mutations in the lineage of cells leading to the sperm or eggs are of particular importance because many such mutations may be shared by somatic tissues and also may be inherited, thus having a lasting consequence. For decades, little has been known about the pattern of the mutation rates along the germline development. Recently it was shown from a small portion of data that resulted from a large-scale mutation screening experiment that the rates of recessive …

Who Participates In An Internet-Based Research Program For Mothers Of Infants? A Secondary Prevention Research Study Among Low-Income Families, Edward G. Feil, Kathleen Baggett, Betsy Davis, Craig Leve, Susan H. Landry, Lisa B. Sheeber

Journal of Applied Research on Children: Informing Policy for Children at Risk

Objective: The objective of this study was to evaluate the participation rates and factors associated with nonparticipation among mothers living in low-income households who were invited to join a parent-education and -support research program delivered via the Internet with professional support.

Methods: Four hundred and seventy-seven mothers of infants were contacted via a variety of recruitment methods, including presentations at clinics/classes, direct mailings, print advertisement, and Internet posts. Research staff attempted to contact these mothers by phone, to assess their eligibility, and interest in participation. For those who were eligible but declined participation, we assessed reasons for declining and collected …

A Commentary On "Parents’ Knowledge, Attitudes, And Beliefs Of Childhood Fever Management In Jordan": The Role Of Healthcare Professionals In Caregiver Fever Phobia, Clay T. Jones

Journal of Applied Research on Children: Informing Policy for Children at Risk

Fever phobia appears to be a universal finding. This is supported by the findings of Athamneh and colleagues in their study, “Parents’ Knowledge, Attitudes, and Beliefs of Childhood Fever Management in Jordan: A Cross-Sectional Study”. The origins of fever phobia likely can be found in the common association of fever and life-threatening illness prior to modern medical advances, but healthcare professionals who care for children must accept partial blame. Overly aggressive management of fever and inaccurate medical information feed into a vicious cycle where patients of more anxious caregivers tend to receive unnecessary interventions. Fever phobia, regardless of where a …

Using Live Coaching And Video Feedback To Teach Responsive Parenting Skills: Experience From The Pals Project, Cathy L. Guttentag

Journal of Applied Research on Children: Informing Policy for Children at Risk

Children living in poverty or born to teenage parents are at increased risk for developmental delays as well as child neglect. Research has shown that one effective avenue for preventive intervention is teaching parents to recognize and respond to their young children’s communicative signals using responsive caregiving behaviors (e.g., warmth and praise, prompt responses linked contingently to the child’s signals, following the child’s interest, stimulating language, and using positive behavior guidance strategies). However, parents with low education and literacy levels are often limited in the degree to which they can benefit from generic instructional materials such as parenting books and …

Understanding The "Big Picture": End-Of-Life Decisions In The Picu, Amy J. Howells

Dissertations and Theses (Open Access)

Objective: Describe critical care providers' cognitive constructions or their interpretation of the process of decision-making that influences both the technique of conversations and the recommendations given to parents regarding limitation or withdrawal of life sustaining treatments from terminally ill children in the PICU. Design: Qualitative Medical Ethnography. Setting: Tertiary care children's hospital affiliated with a college of medicine. Participants: Eleven critical care providers in the department of pediatrics (attending physicians, critical care fellows, pediatric nurse practitioners, physician assistants). Interventions: In depth, semi-structured interviews designed to explore the experiences of providers in the participation of end-of-life care decision-making. Measurements and Main …

Effects Of Resting State On Perceptual Learning, Sarah Eagleman Ph.D.

Dissertations and Theses (Open Access)

Psychophysical experiments in humans have demonstrated that improvements in perceptual learning tasks occur following daytime rests. The neural correlates of how rest influences subsequent sensory processing during these tasks remain unclear. One possible neural mechanism that may underlie this behavioral improvement is reactivation. Previously evoked network activity reoccurs – reactivates - in the absence of further stimulation. Reactivation was initially discovered in the hippocampus but has now been found in several brain areas including cortex. This phenomenon has been implicated as a general mechanism by which neural networks learn and store sensory information. However, whether reactivation occurs in areas relevant …

Investigating The Role Of Exosomal Communication In The Glioma Microenvironment, Javier Figueroa

Dissertations and Theses (Open Access)

Evidence indicates that human cancers are maintained by a population of cells with stem-like properties called cancer stem cells (CSCs). However, the influence of the surrounding stromal cells on the behavior of the CSCs remains poorly understood. We have recently shown that the micro-environment of human gliomas, the most aggressive human brain tumors, contains both glioma stem cells (GSCs) and cells that resemble human bone marrow-derived mesenchymal stem cells (BM-MSCs), called Glioma Associated-MSCs (GA-MSCs). We have also shown that GA-MSCs generate a cytokine-mediated increase in the growth and self-renewal (clonogenicity) of GSCs. However, other paracrine interactions between GA-MSCs and GSCs …

Targeting Breast Cancer With Bacteriophage Associated Silicon Particles, Srimeenakshi Srinivasan

Dissertations and Theses (Open Access)

Nanoparticle based therapeutics have been successfully used in the treatment of breast cancer. Development of nanovectors targeted to cancer cells or elements in the tumor microenvironment has been pursued to improve their site specific accumulation while reducing the non-specific delivery to normal tissues. However, addition of targeting ligands to the surface of nanovectors while maintaining their payload carrying potential is generally challenging. Therefore, there is a critical need to develop surface decoration strategies that allow for effective combination of targeting and payload delivery to the tumor.

In this study, we propose a novel strategy for covering the surface of mesoporous …

Mechanisms Underlying Distinct Egfr Versus Fgfr-3 And -1 Dependency In Human Bladder Cancer Cells, Tiewei Cheng

Dissertations and Theses (Open Access)

The epidermal growth factor receptor (EGFR) and fibroblast growth factor receptor (FGFR) are activated by gene amplification, mutation and overexpression in bladder cancer, which drives tumor development and progression. Both EGFR and FGFR inhibitors are currently being tested in clinical trials. However, bladder cancer (BC) cells show remarkably heterogeneous sensitivities to both inhibitors, and the molecular determinants of this heterogeneity are presently unclear. Therefore, in this study, using selective EGFR and FGFR inhibitors in BC cells, we demonstrated that FGFR3 and FGFR1 play largely non-overlapping roles in mediating proliferation and invasion in the distinct “epithelial” and “mesenchymal” subsets of human …

Gain-Of-Function Mouse Models To Investigate Biological Roles Of Prmt6, Alessandra Di Lorenzo

Dissertations and Theses (Open Access)

Gain-of-function Mouse Models to Investigate Biological Roles of PRMT6

Alessandra Di Lorenzo, Ph.D. Candidate

Mentor: Dr. Mark T. Bedford

Protein Arginine Methyltransferase 6 (PRMT6) is the histone tail writer that methylates the H3R2 (arginine 2 of histone H3) residue, which counteracts the activating H3K4me3 mark. PRMT6 has been shown to behave both as transcriptional co-repressor (i.e. trhrombospondin-1, p21, p53), and co-activator (nuclear receptors). The co-repressor function of PRMT6 is likely the result of H3K4me3 antagonism, while the mechanism by which PRMT6 exerts its co-activator function has yet to be elucidated. PRMT6 is over-expressed in several types of tumors including small …

Development Of A Multi-Purpose Automated Synthesis Module For Production Of Novel Pet Radiopharmaceuticals, I Hong Shih

Dissertations and Theses (Open Access)

Among radiopharmaceuticals of positron emission tomography (PET), ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG) made from commercialized automated synthesis module is the most frequently used in tumor diagnoses. But the false positive findings, such as infectious tissues and post-operative surgical conditions, show strong uptake of ¹⁸F-FDG in PET scans which requires extra clinical procedures to confirm the results. Moreover, the false negative findings, such as low glycolytic activity tumors, reduce the accuracy of PET scans. Therefore, there will be new PET radiopharmaceuticals to redeem the defects of ¹⁸FDG-PET applications.

Current commercialized automated synthesis modules are suitable for clinical use, but …

The Novel Upstream Regulator Of Fbxw7, Ji-Hyun Shin

Dissertations and Theses (Open Access)

SCF^FBXW7 is a tumor suppressor E3 ligase protein that targets numerous oncoproteins such as Cyclin E, c-Myc, c-Jun and MCL1. The deregulation of these proteins often leads to the proliferation of cancer cells. Thus, intracellular stability and functional activity of FBXW7 is critical for regulating cancer. However, there is a gap of knowledge about the intracellular signaling pathway or if there is another ubiquitin ligase that regulates FBXW7 stability. Here, I identify a novel mechanism of FBXW7 stability regulation which involves constitutive photomorphogenic 1 (COP1), AKT and CSN6 (i.e. the COP9 signalosome 6).

COP1 is an E3 ubiquitin ligase …

Imbalance Between Neutrophil Elastase And Elafin Promotes Breast Cancer Growth And Progression, Joseph Anthony Caruso

Dissertations and Theses (Open Access)

Elafin, an endogenous serine protease inhibitor, is a critical component of the epithelial barrier against neutrophil elastase (NE) activity. The central hypothesis examined in this dissertation was that elafin has tumor suppressive properties in breast cancer. In support of this hypothesis, immunohistochemical (IHC) analysis revealed that elafin was downregulated in the majority of invasive breast tumors and a subset of pre-invasive ductal carcinoma in situ (DCIS) compared to elafin expression in the normal mammary epithelium. To understand the role of elafin in the mammary epithelium and the impetus for its downregulation during breast tumorigenesis, primary and immortalized human mammary epithelial …