Neoplasms Commons^™

Genomic Instability And The Oncohistone H3k27m Drive Gliomagenesis In A Murine Model, Lee J. Pribyl

Theses and Dissertations (ETD)

Maintaining genome stability is crucial for human health and it is of particular importance in neural cells during early brain development. Genome maintenance occurs at two broad stages; surveillance during DNA replication and DNA damage repair in differentiating and mature cells. Neural cells are particularly sensitive to DNA strand breaks and defective DNA damage responses can result in detrimental effects on the nervous system, including cancer. Multiple DNA repair pathways play critical roles in preventing DNA damage accumulation in stem and neural progenitor cells. The mechanisms that protect progenitor genomes also suppress DNA mutations that can result in cancer. A …

Black Women Survive Breast Cancer With Community-Based Care, Shelley I. White-Means, Jill Dapremont, Barbara D. Davis, Tronlyn Thompson

Faculty Presentations

PURPOSE Community-based breast cancer support agencies who address non-medical, social determinants of health needs that serve as barriers to maximizing breast health outcomes may play a vital role in mitigating breast cancer mortality. They share a common emphasis on addressing social, economic, and psychological needs of breast cancer survivors and those at risk of breast cancer. This paper is third in a series of papers exploring why the rate of breast cancer mortality is two times higher for African American women than white women in Memphis. We sought insights from community-based breast cancer support agencies because they have a close-up …

Long-Term Functional Effects Of Medulloblastoma Treatments, Serena Khiantani, Pamela Ponce, Bailey Diprima, Sarika Maymoundok, Leah Murray

Master of Occupational Therapy Student Critically Appraised Topics

All studies relate directly to components of the evidence-based practice question and were used to understand the possible long-term effects of treatment for clients diagnosed with medulloblastoma cancer. This Critically Appraised Topic (CAT) contains 6 research articles from both national and international journals. Study designs include two cohort studies with a control group, 1 cross sectional study with a control group, 1 retrospective cohort study without a control group, 1 descriptive report on a Randomized Control Trial (RCT), and 1 descriptive study. Through these studies, we found that radiation treatment is associated with impaired IQ and academic achievement and that …

The Tumor Microenvironment Regulates Retinoblastoma Cell Survival, Zachary K. Goldsmith

Theses and Dissertations (ETD)

Retinoblastoma (Rb) is the most common intraocular malignancy in children comprising 4% of all pediatric tumors. Early intervention increases survival rates up to 95% in developed countries; being survival rates associated to socio-economic status. Despite the high survival rates in developed countries, preservation of the eye and vision are continuing challenges in the management of Rb. Vitreous seeds constitute the greatest challenge in treatment of Rb. The unique location of these seeds within the vitreous makes them difficult to treat. Viable seeds showed reduced proliferative capacity and metabolism. making the majority refractory to current chemotherapeutics. This prompted the development of …

Targeting The Colchicine Binding Site On Tubulin To Overcome Multidrug Resistance And Anticancer Efficacy Of Selective Survivin Inhibitors, Kinsle E. Arnst

Theses and Dissertations (ETD)

Tubulin inhibitors are widely used as chemotherapeutic agents, and their successis attributed to their ability to target microtubule dynamics and disrupt critical cellular functions including cell signaling, motility, intracellular trafficking, and mitosis. Interference with microtubule dynamics consequently disrupts mitotic progression and ultimately leads to apoptosis, validating microtubule dynamics as an excellent target for anticancer agents. While this class of drug has proven to be effective against many cancer types, the clinical efficacy of current tubulin inhibitors is often limited by the development of multidrug resistance. The most common form of resistance to these agents arises from the overexpression of drug …

Role Of Smarce1 And Bhlhe40 In Breast Cancer Metastasis, Aarti Sethuraman

Theses and Dissertations (ETD)

No abstract provided.

Revealing A Non-Canonical Role Of Anti-Apoptotic Mcl-1 In Early Embryonic Development, Xue Yang

Theses and Dissertations (ETD)

MCL-1, a well-known pro-survival BCL-2 family member, is indispensable for the survival of various cellular lineages and is also among the most frequently amplified genes in a variety of human malignancies. Gene ablation studies previously revealed that Mcl-1 deficiency leads to embryonic lethality around E3.5 during peri-implantation stage. Strikingly, the study did not detect any increase in apoptotic cells of the blastocyst, indicating a function of MCL-1 beyond regulating apoptosis. Our previous studies revealed an unrecognized role of MCL-1 in promoting mitochondrial physiology, which is independent of its classical anti-apoptotic function and requires being imported into the mitochondrial matrix. In …

Discovery Of Novel Tubulin Inhibitors And Selective Survivin Inhibitors For Advanced Melanoma And Total Synthesis Of Bioactive 20s-Hydroxyvitamin D3, Qinghui Wang

Theses and Dissertations (ETD)

According to the statistics from American Cancer Society, the 5-year survival rate for patients with advanced melanoma is as low as 5%. Treatment of advanced melanoma, therefore, represents an unmet medical need. In this dissertation, I will show the effort to develop new generations of bioavailable tubulin inhibitors targeting the colchicine binding site and selective small-molecule survivin inhibitors for treating advanced melanoma. Extensive structure-activity relationship (SAR) studies of lead molecules ABI-231 and UC-112 have been performed.

Chapter 1 will introduce the current situation of advanced or metastatic melanoma, its clinical drug treatments, as well as problems in current drug treatments. …

Metabolic Regulation Of Cellular Signaling, Rashid John Darbandi

Theses and Dissertations (ETD)

Using the biochemically tractable Xenopus oocyte model system, we have previously characterized a novel metabolic regulation of cell death. We found that glucose-6-phosphate (G6P) via the pentose phosphate pathway leads to increased nicotinamide adenine dinucleotide phosphate (NADPH) levels, a subsequent increase in cytosolic acetyl-coenzyme A and activation of Ca2+/calmodulin-dependent protein kinase II (CaMKII). We recently identified coenzyme A (CoA), derived from the breakdown of acetyl-CoA, as the key metabolic signal that mediates a novel mechanism of calmodulindependent activation of CaMKII. CoA binds directly to the calmodulin (CaM) binding domain (CaMBD) of CaMKII resulting in its activation and downstream inhibitory phosphorylation …

Using S. Pombe To Study The Biological Roles Of The Histone Deacetylases Sir2 And Clr3 And The Dead-Box Rna Helicase Ded1, Brandon Ray Lowe

Theses and Dissertations (ETD)

The fission yeast Schizosaccharomyces pombe provides a good model system to quickly study basic mechanisms underlying biological pathways conserved in higher eukaryotes. Here we utilized fission yeast to study the roles of the histone deacetylases (HDACs) Sir2 and Clr3 in heterochromatin formation and cancer associated mutations of the DEAD-box RNA helicase DDX3X, homolog of fission yeast Ded1, in translational control. Heterochromatin in fission yeast is characterized by hypoacetylation as well as methylation of histone H3 on lysine 9 (H3K9me). Heterochromatin assembly can now be separated into three distinct steps: heterochromatin establishment, spreading, and maintenance. These steps involve the actions of …

Therapeutic Effects Of Ormeloxifene In Cervical Cancer Carcinogenesis, Neeraj Chauhan

Theses and Dissertations (ETD)

Cervical cancer (CxCa) remains the fourth leading cause of cancer related deaths among women worldwide. Cervical cancer is mainly (~ 99.7%) derived from high risk Human papillomavirus (HR HPV). HPV E6/E7 are the two main oncoproteins that interfere with p53 and pRb (retinoblastoma) cell cycle regulatory proteins and hinder their efficacy of controlling cell growth. Additionally, PI3K-Akt is a cell survival pathway that is aberrantly expressed in cervical cancer cells. This pathway has a profound role in inhibiting mitochondrial intrinsic apoptotic signaling pathway. Advanced stage cervical cancer is difficult to treat and patients diagnosed with metastatic disease have a poor …

The Roles Of Nuclear Receptor Nr4a1 In Cancer Cell Proliferation And Skeletal Muscle Differentiation, Alexa Farmer

Theses and Dissertations (ETD)

Nuclear receptors (NRs) constitute a major class of drug targets in the treatment of various cancer types. NRs respond to cellular signals and become activated upon ligand binding to transcriptionally modulate expression of target genes. NR4A1 (Nur77) is a member of the NR4A family of nuclear receptors and displays an oncogenic profile in many cancer models. It is often upregulated in adult solid malignancies and is known to promote cell proliferation and survival. Knockdown studies of NR4A1 in cancer cell lines results in decreased cell growth and angiogenesis and increased apoptosis, suggesting NR4A1 is an oncogenic protein. Due to the …

Novel Oncogenic Drivers In Pediatric Gliomagenesis, Alexander K. Diaz

Theses and Dissertations (ETD)

Pediatric high-grade gliomas (pHGGs), with a two-year survival rate of less than 20%, are some of the most aggressive human cancers. This dissertation begins with our analysis of 127 pHGGs, including brainstem (BS) and non-brainstem (NBS) tumors, from 118 patients using next-generation sequencing technologies. Nearly one-third of BS-HGGs, also known as diffuse intrinsic pontine gliomas (DIPGs), harbored somatic heterozygous missense mutations in ACVR1, coding for a receptor serine-threonine kinase involved in bone morphogenetic protein (BMP) signaling. These alterations led to gain-of-function as evidenced by increased phosphorylation of downstream targets in primary astrocytes and zebrafish embryo ventralization. Whole-genome sequencing and …

Health-Related Quality Of Life In Children With Cancer, Tha'er Ghandi Almomani

Theses and Dissertations (ETD)

Health-related quality of life is an important phenomenon to measure in children undergoing treatment for cancer. However, the effects of different treatment modalities and cancer related factors over the duration of treatment have not been explored. To assess the effects of different child-, cancer-, and treatment-related factors, we analyzed a large sample of children undergoing curative treatment for 5 different childhood cancer diagnoses. These diagnostic groups were Hodgkin Lymphoma (HL), Acute Lymphoblastic Leukemia (ALL), Acute Myeloid Leukemia (AML), Osteosarcoma (OS), and Melanoma. We analyzed a sample of 710 patients across the five diagnostic groups over four time-points in treatment. These …

Anal Cancer Risk Factor Management Practices And The Barriers And Facilitators Of Addressing Anal Health In The Hiv Primary Care Setting, Crystal Martin Walker

Theses and Dissertations (ETD)

Background: The incidence of anal cancer is only 1-2 per 100,000 people in the general population, but in people living with HIV and AIDS (PLWHA), the incidence is far greater by about 80 times. This is a striking disproportion, and it is vital for the healthcare provider and healthcare system to become more attentive to the risk of anal cancer in high-risk populations such as PLWHA. There are a number of modifiable risk factors for anal cancer in PLWHA such as smoking, non-adherence to antiretroviral therapy (ART), and risky sexual behaviors. The HIV primary care provider (HIV PCP) plays a …

Molecular Characterization Of Glioblastoma Cancer Stem Cells, Jo Meagan Garner

Theses and Dissertations (ETD)

Malignant gliomas are locally aggressive, highly vascular tumors that have an overall survival time less than 14 months, and current therapies provide little improvement in the disease course and outcome. While glioblastoma multiforme (GBM) patients present uniform histological phenotypes, the molecular determinants of the disease vary considerably between individual cases resulting in complicated prognosis. The heterogeneity, aggressiveness and rapid tumor relapse of GBM is believed to be sustained by cancer stem-like cell populations that are able to initiate and maintain tumors. Although CSCs represent only a small fraction of cells within a tumor, their high tumor-initiating capacity and therapeutic resistance …

Development And Characterization Of A Recombinant Vesicular Stomatitis Virus (Rvsv) For The Treatment Of Glioblastoma, Erika A. Dillard

Theses and Dissertations (ETD)

Background: Over the past 30 years, little has changed in the treatment modalities and prognosis of patients suffering from Glioblastoma multiforme (GBM), the most common and by far the most devastating adult primary malignant brain tumor. Conventional therapies provide only a marginal increase in survival of GBM patients, post-diagnosis. Therefore, more novel means of treating GBM are needed to increase long-term survival and quality of life for those affected. Replication competent oncolytic viruses (OVs) have recently emerged as a possible option for treatment of high-grade gliomas. Particularly, recombinant vesicular stomatitis virus (rVSV), an enveloped, negative strand RNA virus, has shown …

Nkg2d Ligands In Cancer, Neha Das Gupta

Theses and Dissertations (ETD)

NK cell transplantation has been increasingly used to treat cancers that are resistant to chemotherapy. However, not all cancers are susceptible to NK cell killing. The prevalence and mechanisms of NK cell resistance have not been well elucidated. Because NKG2D is a major activating receptor on NK cells, we sought to test the hypothesis that NKG2D is the primary pathway in tumor cell recognition. Herein, we comprehensively assessed 20 cancer cell lines representing a broad array of cancer types. In line with our primary hypothesis, no cancer cell lines that expressed low levels of NKG2D ligands were susceptible to NK …

Tetraspanin Cd9: Contributions To Cancer Cell And Vascular Cell Phenotypes From The Sixth Man, Michael James Herr Ii

Theses and Dissertations (ETD)

Cancer and vascular disease are the two most predominant causes of mortality in the United States. Potential regulatory mechanisms for these two diseases have consumed research interests. Tetraspanins are cell surface proteins that organize the cell membrane. Cellular membrane organization is a prerequisite for cellular signaling to occur. Deregulation of cellular signaling often precedes the formation of cancer or vascular disease phenotypes. This insinuates the necessity to understand how tetraspanins contribute to membrane organization and subsequent downstream signaling. This work examines tetraspanin CD9 contributions in a model of cancer cell invasion and vascular cell contraction. The findings presented here demonstrate …

Identification Of Novel Hif1a Target Genes That Regulate Tumor Progression And Metastasis, Danielle L. Peacock

Theses and Dissertations (ETD)

Hypoxia is a hallmark of most solid tumors. In response to hypoxic stress tumor cells adapt by regulating survival, metabolism and angiogenesis. The heterodimeric HypoxiaInducible Factor (HIF) transcription factors are the master regulators of this response. HIFs play key roles in many critical aspects of cancer biology including angiogenesis, stem cell maintenance, metabolic reprogramming, invasion, metastasis and resistance to radiation therapy and chemotherapy. Overexpression of HIF-1α and HIF-2α has been documented in multiple human cancers and HIF-1 protein is over-expressed in ~30% of primary breast tumors and ~70% of metastases, which independently correlates with poor prognosis and decreased survival in …

The Protumorigenic Role Of Caspase-8 In Neuroblastoma, Devin Drew Twitchell

Theses and Dissertations (ETD)

Neuroblastoma (NB), the most common extracranial solid tumor in children, accounts for 15% of cancer-related deaths in pediatric patients. Caspase-8 (casp8), a proapoptotic protein, is silenced in approximately, 50-70% of neuroblastoma patient samples. Loss of casp8 has been suggested to increase NB metastasis and correlated, in some studies, with advanced-stage NB. Furthermore, decreased casp8 expression may facilitate neuroblastoma tumorigenesis by protecting cells from cell death mediated by either integrins or chemotherapeutics. Paradoxically, casp8 expression is maintained in 30-50% of NB patient samples giving rise to the possibility that casp8 may provide selective advantages for NB tumorigenesis. Caspase-8 is shown to …

Functional Study Of Hemogen Knockout Mouse Model, Peng Gao

Theses and Dissertations (ETD)

Mouse Hemogen (Hemgn) is regarded as a homologue of human Erythroid Differentiation Associated Gene (EDAG). EDAG overexpression has been postulated for association with some leukemia cases. Meanwhile, Hemgn has been found to contribute to Hoxb4 mediated hematopoietic stem cell expansion. Based on these postulations and evidences, a Hemgn knockout mouse model has been generated to study its function in normal and stress hematopoiesis. I confirmed the Hemgn expression in hematopoietic organs including bone marrow and spleen, as well as round spematids in testis. Hemgn is expressed in mouse hematopoietic stem cells and erythroid progenitor cells. Moreover, Hemgn was also found …

The Role Of The Yxxφ Motif In Cd82 Trafficking And Function, Mekel Marie Richardson

Theses and Dissertations (ETD)

CD82, a tetraspanin, is a tumor metastasis suppressor. Tetraspanins are membrane spanning proteins that play critical roles in diverse biological and pathological processes, e.g., the regulation of cancer metastasis. CD82 is ubiquitously expressed in various types of tissues, but its expression becomes down-regulated or lost in a majority of metastatic tumors. It inhibits tumor metastasis without affecting primary tumor growth. Cancer patients whose tumors contain CD82 exhibit minimal metastasis. We know that CD82 functions as a tumor metastasis suppressor but the mechanism by which this occurs is largely unknown. CD82 can be found on the plasma membrane as well as …

Inhibition Of Breast Cancer Angiogenesis And Metastasis Ay Targeting Hypoxia-Inducible Factor-1Α, Chikezie O. Madu

Theses and Dissertations (ETD)

The current clinical chemotherapy agents are not ideal for breast cancer as they are not curative, but only provide a modest extension of survival with sometimes a severely adverse effect on the patient’s quality of life. There is, therefore, an urgent need to search for new and more effective anti-breast cancer drugs. However, the existing screening system is inefficient and time-consuming despite the extremely large amount of small molecule compounds in database currently available, and thereby hindering the effort for selecting new and effective anti-cancer drugs.

The majority of locally advanced solid tumors contain regions of reduced oxygen availability. Hypoxia …

Discovery Of Dihydroartemisinin And Dasatinib Drug Combination To Cure Pooroutcome Bcr-Abl+ Acute Lymphoblastic Leukemia, Harpreet Singh

Theses and Dissertations (ETD)

Oncogenic signaling by the Philadelphia chromosome-encoded BCR-ABL fusion kinase initiates and drives both Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) and chronic myelogenous leukemia (CML). Food and Drug Administration (FDA)- approved BCR-ABL-specific kinase inhibitors (BCR-ABL–KIs) imatinib, dasatinib and nilotinib induce prolonged remissions in CML but poor leukemia-reduction and relapse-control in Ph+ ALL. The relative primary BCR-ABL–KI-resistance in Ph+ ALL patients carrying predominantly BCR-ABLWT disease cannot be attributed to drug-resistant BCR-ABL mutations (BCR-ABLMUTANTS), and remains poorly understood.

We established a cell-based platform to evaluate the modulation of anti-Ph+ ALL activity of drugs by both tumor-extrinsic cytokines normally present in the leukemia …

Insights Into P53-Dependent Apoptotic Signaling And Cell Fate Vis-A-Vis Functional Cooperation Among Bcl-Xl, Cytoplasmic P53, And Puma, John C. Fisher

Theses and Dissertations (ETD)

Following DNA damage, nuclear p53 induces the expression of PUMA (p53 upregulated modulator of apoptosis), a BH3‑only protein that binds and inhibits the anti‑apoptotic BCL‑2 repertoire, including BCL‑xL. Structural investigations of PUMA and the BCL‑xL×PUMA BH3 domain complex by X‑ray crystallography and nuclear magnetic resonance (NMR) spectroscopy reveal a novel, PUMA‑induced, domain‑swapped dimerization of BCL‑xL that requires a π‑stacking interaction between PUMA W71 and BCL‑xL H113. PUMA is an intrinsically disordered protein, but upon interaction with BCL‑xL, PUMA W71 and the PUMA BH3 domain residues fold into an alpha helix and subtly remodel BCL‑xL to trigger its dimerization. Wild type …

Cd151 Reinforces Vascular Stability By Balancing Endothelial Cell Adhesion And Cytoskeletal Tension, Feng Zhang

Theses and Dissertations (ETD)

Tetraspanin CD151 is highly expressed in endothelial cells and regulates pathological angiogenesis. However, the mechanism by which CD151 promotes vascular morphogenesis and whether CD151 engages other vascular functions are unclear. We observed that CD151 is required for the maintenance of endothelial capillary-like structures formed in vitro and the integrity of lung endothelial cell-cell contacts in vivo. As a master regulator of endothelial cell-matrix and cell-cell adhesions, CD151 is needed for the optimal functions of various cell adhesion proteins such as integrin, cadherin, and CD44. The loss of CD151 elevates the cellular intrinsic contraction by upregulating RhoA signaling and downregulating of …

Tamoxifen: Mechanisms Of Resistance, Cyrus Mccoy Adams

Theses and Dissertations (ETD)

The role of estrogen in breast cancer has been recognized for decades. The selective estrogen receptor modulator tamoxifen was the first targeted therapy for the treatment of breast cancer. It was also the first drug approved by the FDA for the reduction of breast cancer risk. While tamoxifen has extended the lives of countless patients with breast cancer, resistance to tamoxifen remains a significant clinical problem. Work over the last two decades has greatly enhanced our understanding of the molecular mechanisms by which breast cancer cells may become resistant to tamoxifen treatment. Here I review our current understanding of the …

Evaluating The Impact Of The Guatemalan Nursing Program On Staff, Organizational, And Clinical Outcomes, Sara Williamson Day

Theses and Dissertations (ETD)

There is great disparity between the outcome of childhood cancer in developed and developing countries. Nurses, who comprise the largest group of health care professionals globally, are essential to successful treatment. Pediatric oncology education is generally unavailable for nurses in developing countries. This lack of education is likely to contribute to the disparity in survival rates, as undereducated nurses are unable to meet the demands of pediatric cancer care. A second critical problem in developing countries is the workload of the nurse, with a patient nurse ratio reported as high as 30 patients per one nurse.

In 2006, the quality …

The Use Of Preclinical Models To Improve The Treatment Of Retinoblastoma, Katie Marie Nemeth

Theses and Dissertations (ETD)

Rodent models play an essential role in the development of new chemotherapeutics and dosing regimes. It is often difficult to carryout a clinical study for pediatric cancers due to the small patient population. Retinoblastoma, a pediatric cancer of the eye, is one example of a pediatric cancer that can benefit from preclinical studies. Over the years various retinoblastoma rodent models have been developed used to test various combination of broad-spectrum systemic chemotherapy. It was found form these studies that the combination of topotecan and carboplatin was effective. However both drugs cause myelosuppression and therefore administrating both of these drugs systemically …