Cell and Developmental Biology Commons^™

P53 Dimers Elicit Unique Tumor Suppressive Activities Through An Altered Metabolic Program, Jovanka Gencel-Augusto

Dissertations & Theses (Open Access)

p53 is the most frequently mutated tumor suppressor in human cancer. As a tetrameric transcription factor, mutation of the p53 Tetramerization Domain (TD) is a mechanism by which cancers abrogate wild-type (WT) p53 function. p53 TD mutations result in a protein that preferentially forms monomers or dimers. These are also normal p53 states under basal cellular conditions. Although it is accepted that tetrameric p53 is required for full tumor suppressive activities, the physiological relevance of monomeric and dimeric states of p53 is not well understood. We have established in vivo models for monomeric and dimeric p53 which model Li-Fraumeni Syndrome …

Mutant C. Elegans P53 Together With Gain-Of-Function Glp-1/Notch Decreases Uvc-Damage-Induced Germline Cell Death But Increases Parp Inhibitor-Induced Germline Cell Death, Jorge Canar, Prima Manandhar-Sasaki, Jill Bargonetti

Publications and Research

The TP53 gene is mutated in over 50% of human cancers, and the C. elegans p53-1 (cep-1) gene encodes the ortholog CEP-1. CEP-1 is activated by ultraviolet type C (UVC)-induced DNA damage and activates genes that induce germline apoptosis. UVC treatment of gain-of-function glp-1(ar202gf)/Notch tumorous animals reduces germline stem cell numbers (and overall tumor size), while UVC treatment of double-mutant cep-1/p53(gk138);glp-1/Notch(ar202gf) increases DNA damage adducts and stem cell tumor volume. We compared UVC-induced mitotic stem cell death and animal lifespans for the two different C. elegans tumorous strains. C. elegans stem cell compartment death has never been observed, and we …

Determining The Roles Of The Oligomerization And C-Terminal Domains In Mutant P53 Gain-Of-Function Activities, George K. Annor

Dissertations, Theses, and Capstone Projects

The tumor suppressor p53 (TP53) gene is often mutated in cancer, with missense mutations found in the central DNA binding domain, and less often in the oligomerization domain (OD) and C-terminal domain (CTD). The OD and CTD have been found to be critical for the tumor suppressor functionality of wild-type p53 (wtp53). Specific missense mutations in the DNA binding domain have been found to confer new gain-of-function (GOF) activities. Mutations that destabilize tetramer formation, or deletion of key lysine residues within the CTD, downregulate the ability of wtp53 to transactivate (increase the rate of transcription of) its target …

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

Dissertations & 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 …

Discovery Of Sex Differences In Response To P53 Loss And Gain-Of-Function In Glioblastoma, Nathan Cuyle Rockwell

Arts & Sciences Electronic Theses and Dissertations

The tumor suppressor TP53 (p53) is the most frequently mutated gene in cancer and among the most mutated genes in brain cancer. Functionally, p53 is a transcription factor that, when activated by an array of stress stimuli, regulates a complex transcriptional program that contributes to a variety of antiproliferative pathways. The loss of p53 function (LOF), either through mutation, deletion, or inhibition by alterations in the proteins that regulate p53, removes an essential barrier to the unfettered proliferation and genomic instability that drive transformation. Unlike most tumor suppressors, many p53 mutations are missense mutations that lead to stable expression of …

The Role Of Autophagy And Senescence In The Responses Of Non-Small Cell Lung Cancer Cells To Chemotherapy And Radiation, Nipa H. Patel

Theses and Dissertations

Cancer-associated deaths account for the second-highest mortality rates in the United States. Primary modalities of treatment often include surgery, radiation, and chemotherapy, and may also incorporate targeted therapy and immunotherapy. However, resistance to these treatments remains high, resulting in disease reoccurrence and poor survival rates. While apoptosis or cell death of tumor cells is the ideal outcome for anti-cancer therapy, this is often not the case, and in fact cancer cells may upregulate several pathways, such as autophagy and senescence, as a means to undergo alternative cell fate and evade apoptotic cell death. An essential tumor suppressor gene, TP53, …

P53 Drives A Transcriptional Program That Elicits A Non-Cell-Autonomous Response And Alters Cell State In Vivo, Sydney Moyer

Dissertations & Theses (Open Access)

Cell stress and DNA damage activate the tumor suppressor p53, triggering transcriptional activation of a myriad of target genes. The molecular, morphological, and physiological consequences of this activation remain poorly understood in vivo. We activated a p53 transcriptional program in mice by deletion of Mdm2, a gene which encodes the major p53 inhibitor. By overlaying tissue-specific RNA-sequencing data from pancreas, small intestine, ovary, kidney, and heart with existing p53 ChIP-sequencing, we identified a large repertoire of tissue-specific p53 genes and a common p53 transcriptional signature of seven genes which included Mdm2 but not p21. Global p53 activation …

Study Of Alpha Mangostin As A Chemoprotective Agent For Breast Cancer Via Activation Of The P53 Pathway, Vanessa Van Oost

Honors Program Projects

Breast carcinoma is the most frequently diagnosed cancer among women and causes over 400,000 deaths each year worldwide. Current treatments such as chemotherapy are not selective for cancerous tissues but are destructive to normal tissues as well. This causes a range of side effects including pain, nausea, hair loss, weakness, and more. Inactivation of p53 is a very common mutation within human cancer cells. The ability to activate the p53 pathway which protects cells from tumor formation is lost in 50% of cancers. Due to the prevalence of this mutation, p53 is a uniquely valuable target for applied research. Alpha …

Alpha Mangostin As A Chemoprotective Agent Via Activation Of The P53 Pathway For Breast Cancer, Vanessa Van Oost

Scholar Week 2016 - present

Breast carcinoma is the most frequently diagnosed cancer among women and causes over 400,000 deaths yearly worldwide. Current treatments such as chemotherapy are not selective for cancerous tissues but are destructive to normal tissues as well. This causes a range of side effects including pain, nausea, hair loss, weakness, and more. Inactivation of p53 is an almost universal mutation within human cancer cells. The ability to activate the p53 pathway which protects cells from tumor formation is lost in 50% of cancers. Due to the prevalence of this mutation, p53 is a uniquely valuable target for applied research. Alpha mangostin …

Effects Of Bisphenol-S And Estrogen On P53 Expression In Ovarian Tissue Of Zebrafish (Danio Rerio), Jess Fairbanks

Summer Research

Bisphenol A (BPA) is one the most widely used plasticizing compounds. As an endocrine disruptor, BPA could affect ovarian function and embryonic development. Bisphenol S (BPS) has been used in many plastics and resins in lieu of BPA. However, the effects of BPS are not widely known. Apoptosis is a type of genetically programmed cell death that is important in ovarian homeostasis. One of the genes that regulates apoptosis, p53, has been shown to respond to estrogen in maintaining ovarian homeostasis. We have investigated how exposure to estrogen and to BPS affects p53 expression in ovarian tissue in vitro …

Cd147 As A Potential Therapeutic Target In Glioblastoma Treatment, Beau Adams

All NMU Master's Theses

Glioblastoma (GBM) tumors are the most common and lethal form of cancer in the central nervous system (CNS). GBM tumors appear to contain a mixture of different cell types, which makes them difficult to treat. GBM cells exhibit altered morphology from normal cells on several different levels, which highlights different pathways to potentially target for therapeutic treatments. The human surface glycoprotein CD147, also known as basigin, is expressed at significantly higher levels in GBMs compared to non-neoplastic brain tissue. Furthermore, levels of CD147 expression correlate with brain tumor progression and show the highest expression in GBM. Here, we suppressed tumor …

Trim24 As An Oncogene In The Mammary Gland, Aundrietta Duncan

Dissertations & Theses (Open Access)

Despite the many advances made in breast cancer research and treatments, breast cancer remains one of the deadliest diseases plaguing women worldwide. While many findings on genetic mutations and their role in predisposing people to breast cancer have been uncovered, we are just beginning to understand the extent to which epigenetic regulators promote tumorigenic phenotypes, metastasis, and chemotherapeutic resistance. Moreover, new experimental tools offer the ability to address questions we were previously unable to assess. My project takes advantage of a new mouse model to understand the role of a proto-oncogenic, transcriptional co-regulator, TRIM24, in mammary gland development and disease. …

Phosphorylation Impairs Dicer1 Function To Accelerate Aging And Tumorigenesis In Vivo, Neeraj Aryal

Dissertations & Theses (Open Access)

Altered DICER1 protein levels are associated with developmental disorders, infertility, macular degenerative blindness, aging, and cancer in humans. Recently, post-translational regulation of Dicer1 via phosphorylation has been described in C. elegans. Oscillation of Dicer1 phosphorylation to regulate its activity is essential for germ cell development and embryogenesis in worms. These observations led us to posit that Dicer1 protein levels and activity are under tight regulation for normal mammalian homeostasis. To test whether phosphorylation of Dicer1 regulates its activity in mammals, I generated phospho-mimetic knock-in mouse models by replacing Serines 1712 and 1836 with Aspartic acids individually or together (dual …

Resveratrol And Pterostilbene Exhibit Anticancer Properties Involving The Downregulation Of Hpv Oncoprotein E6 In Cervical Cancer Cells, Kaushiki Chatterjee, Dina Alsharif, Christina Mazza, Palwasha Syar, Mohamed Al Sharif, Jimmie E. Fata

Publications and Research

Cervical cancer is one of the most common cancers in women living in developing countries. Due to a lack of affordable effective therapy, research into alternative anticancer compounds with low toxicity such as dietary polyphenols has continued. Our aim is to determine whether two structurally similar plant polyphenols, resveratrol and pterostilbene, exhibit anticancer and anti-HPV (Human papillomavirus) activity against cervical cancer cells. To determine anticancer activity, extensive in vitro analyses were performed. Anti-HPV activity, through measuring E6 protein levels, subsequent downstream p53 effects, and caspase-3 activation, were studied to understand a possible mechanism of action. Both polyphenols are effective agents …

Cxcr2 Is A Negative Regulator Of P21 In P53-Dependent And Independent Manner Via Akt-Mediated Mdm2 In Ovarian Cancer, Rosa Mistica C. Ignacio, Yuan-Lin Dong, Syeda M. Kabir, Hyeongjwa Choi, Eun-Sook Lee, Alicia Beeghly-Fadiel, Margaret M. Whalen, Deok-Soo Son

Chemistry Faculty Research

Ovarian cancer (OC) has the highest rate of mortality among gynecological malignancy. Chemokine receptor CXCR2 in OC is associated with poor outcomes. However, the mechanisms by which CXCR2 regulates OC proliferation remain poorly understood. We generated CXCR2-positive cells from parental p53 wild-type (WT), mutant and null OC cells, and assessed the roles of CXCR2 on proliferation of OC cells in p53-dependent and independent manner. CXCR2 promoted cell growth rate: p53WT > mutant = null cells. Nutlin-3, a p53 stabilizer, inhibited cell proliferation in p53WT cells, but had little effect in p53-mutant or null cells, indicating p53-dependence of CXCR2-mediated proliferation. CXCR2 decreased …

The Role Of Mdm2 In Dna Damage Signaling, Stanley Tam

Theses and Dissertations

The overexpression of the oncogene MDM2 is common in a variety of human cancers. MDM2 overexpression is known to increase genome instability in cells by delaying DNA double strand break repair and γH2AX levels. This study explores the knockdown of MDM2 and how it may affect DNA damage signaling.

Wild-Type P53 Enhances Endothelial Barrier Function By Mediating Rac1 Signalling And Rhoa Inhibition, Nektarios Barabutis, Christiana Dimitropoulou, Betsy Gregory, John D. Catravas

Bioelectrics Publications

Inflammation is the major cause of endothelial barrier hyper-permeability, associated with acute lung injury and acute respiratory distress syndrome. This study reports that p53 "orchestrates" the defence of vascular endothelium against LPS, by mediating the opposing actions of Rac1 and RhoA in pulmonary tissues. Human lung microvascular endothelial cells treated with HSP90 inhibitors activated both Rac1- and P21-activated kinase, which is an essential element of vascular barrier function. 17AAG increased the phosphorylation of both LIMK and cofilin, in contrast to LPS which counteracted those effects. Mouse lung microvascular endothelial cells exposed to LPS exhibited decreased expression of phospho-cofilin. 17AAG treatment …

Carbohydrate-Based Inducers Of Cellular Stress For Targeting Cancer Cell Metabolism, Fidelis Ndombera

Wayne State University Dissertations

ABSTRACT

CARBOHYDRATE-BASED INDUCERS OF CELLULAR STRESS FOR TARGETING CANCER CELL METABOLISM

by

FIDELIS TOLOYI NDOMBERA

May 2018

Advisor: Dr. Young-Hoon Ahn

Major: Chemistry (Biochemistry)

Degree: Doctor of Philosophy

Metabolic reprogramming and redox control of cancer cells is vital for their proliferation, but also provides selective strategies for treating cancer. Increased generation of reactive oxygen species (ROS) and an intricate control of redox status in cancer cells relative to normal cells provide a basis for designing ROS-inducing anticancer agents. In my work, I designed, synthesized and evaluated carbohydrate-based small molecules for ROS-generation, cytotoxicity and redox signaling and stress response. Our data …

Targeting Ribosome Assembly Factors Selectively Protects P53 Positive Cells From Chemotherapeutic Agents, Russell T. Sapio, Anastasiya Nezdyur, Matthew Krevetski, Leonid Anikin, Vincent J. Manna, N. Minkovsky, Dimitri G Pestov

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Many chemotherapeutic agents act in a nondiscriminatory fashion, targeting both cancerous and noncancerous cells in Sphase and Mphase. One approach to reduce the toxic side effects in normal tissue is to exploit the differences in p53 functionality between cancerous and noncancerous cells. For example, activating p53 signaling by nongenotoxic means can transiently arrest noncancerous p53 positive cells in G1 phase and protect them from the cytotoxic effects of chemotherapeutic drugs. However, since most cancerous cells have faulty p53 signaling, they will proceed to cycle, and continue to be affected by the drug. In this study we asked if this G1‐phase …

The Role Of Cytoplasmic Polyadenylation Element Binding Protein -2 (Cpeb-2) In Human Breast Cancer, Joshua Tordjman

Electronic Thesis and Dissertation Repository

Cyclooxygenase-2 (COX-2) is overexpressed in 40-50% of breast cancers, and promotes tumour progression through increased proliferation, migration, invasion, Epithelial-to-Mesenchymal Transition (EMT), and induction of therapy-resistant Stem-Like-Cells (SLCs). COX-2 stimulates expression of two oncogenic and SLC-promoting microRNAs (miR-526b, miR-655), which simultaneously target one gene, Cytoplasmic Polyadenylation Element Binding Protein-2 (CPEB-2). Hypothesis: CPEB-2 is a tumour- and SLC-suppressing gene in breast cancer. Results: CPEB-2 knockout in a non-tumourigenic mammary epithelial cell line MCF10A demonstrated increases in proliferation, migration, invasion, EMT markers, SLC content, and VEGF-D expression. CPEB-2, an mRNA-binding translation-regulating protein, was found to regulate the translation of tumour suppressor p53. When …

Chloroquine-Inducible Par-4 Secretion Is Essential For Tumor Cell Apoptosis And Inhibition Of Metastasis, Ravshan Burikhanov, Nikhil Hebbar, Sunil K. Noothi, Nidhi Shukla, James Sledziona, Nathália Araujo, Meghana Kudrimoti, Qing Jun Wang, David S. Watt, Danny R. Welch, Jodi Maranchie, Akihiro Harada, Vivek M. Rangnekar

Radiation Medicine Faculty Publications

The induction of tumor suppressor proteins capable of cancer cell apoptosis represents an attractive option for the re-purposing of existing drugs. We report that the anti-malarial drug, chloroquine (CQ), is a robust inducer of Par-4 secretion from normal cells in mice and cancer patients in a clinical trial. CQ-inducible Par-4 secretion triggers paracrine apoptosis of cancer cells and also inhibits metastatic tumor growth. CQ induces Par-4 secretion via the classical secretory pathway that requires the activation of p53. Mechanistically, p53 directly induces Rab8b, a GTPase essential for vesicle transport of Par-4 to the plasma membrane prior to secretion. Our findings …

Targeting Apoptotic Pathways To Overcome Drug Resistance In Acute Myeloid Leukemia, Rongqing Pan

Dissertations & Theses (Open Access)

Evasion of apoptosis is integral to tumorigenesis and drug resistance. BCL-2 and p53 proteins represent two focal nodes in convergent apoptosis signaling. Upregulation of anti-apoptotic BCL-2 family members and inactivation of p53 functions are two canonical approaches exploited by cancer cells to escape apoptosis. In the current study, we find that BCL-2 protein is highly expressed in acute myeloid leukemia (AML) cells. BCL-2–specific inhibitor ABT-199 potently induces mitochondrial apoptosis in AML cells and effectively kills AML stem/progenitor cells. Our biomarker studies demonstrate that both BH3 profiling and the expression profiling of BCL-2 proteins may serve as predictive biomarkers for the …

Using Mouse Models To Define How The P53 R72p Polymorphism Impacts The Adverse Effects Of Doxorubicin And Ionizing Radiation, Emily Dominguez

Dissertations & Theses (Open Access)

The single nucleotide polymorphism (SNP) at codon 72 of the tumor suppressor gene p53 codes for either an arginine (R) or proline (P) (p53 R72P). This SNP may impact how cells respond to genotoxic insult. Studies in cell culture and in tissues from mouse models of the SNP indicate that, in response to gentoxic treatment, the two variants may differentially induce apoptosis and expression of p53 target genes. In epidemiological studies, the P variant is associated with decreased cancer survival and increased risk of side-effects from genotoxic cancer treatment. Genotoxic therapy is still the mainstay of cancer treatment, and doxorubicin …

Investigating The Roles Of Δnp63 As A Suppressor Of Migration, Invasion, And Metastasis, Ramon E. Flores Gonzalez

Dissertations & Theses (Open Access)

Cancer is one of the leading causes of death and disease in the world. Considerable resources are spent to study and understand cancer, with the hope of developing new treatments and eventually cures that will help millions of people. Efforts to understand cancer are hindered by its inherent complexity and instability. Nonetheless, understanding the basics of tumor development and progression are the key to focused on studying the role of ΔNp63 in cancer, a p53 family member known to be involved in epithelial development, microRNA biogenesis, and stem cell maintenance. Using the strength of in vivo mouse models, we found …

Tricurin, A Novel Formulation Of Curcumin, Epicatechin Gallate, And Resveratrol, Inhibits The Tumorigenicity Of Human Papillomaviruspositive Head And Neck Squamous Cell Carcinoma, Longzhu Piao, Sumit Mukherjee, Qing Chang, Xiujie Xie, Hong Li, Mario R. Castellanos, Probal Banerjee, Hassan Iqbal, Ryan Ivancic, Xueqian Wang, Theodoros N. Teknos, Quintin Pan

Publications and Research

Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent cancer worldwide with about 600,000 new cases diagnosed in the last year. The incidence of human papillomavirus-positive head and neck squamous cell carcinoma (HPV-positive HNSCC) has rapidly increased over the past 30 years prompting the suggestion that an epidemic may be on the horizon. Therefore, there is a clinical need to develop alternate therapeutic strategies to manage the growing number of HPV-positive HNSCC patients. TriCurin is a composition of three food-derived polyphenols in unique stoichiometric proportions consisting of curcumin from the spice turmeric, resveratrol from red grapes, and …

The Role Of Gdf15 In Ovarian Cancer, Daisy I. Izaguirre

Dissertations & Theses (Open Access)

Growth Differentiation Factor 15 (GDF15) is induced in situations such as stress, inflammation, treatment with non-steroidal anti-inflammatory drugs, as well as other therapeutic agents. As a secreted protein, GDF15 is seen as a potential biomarker in several types of cancer as well as in other diseases such as cardiovascular diseases, diabetes, and rheumatoid arthritis. In ovarian cancer, high GDF15 serum levels correspond to poor survival. It has further been shown to be expressed at higher levels in serum in ovarian cancer patients post-chemotherapy than pre-chemotherapy.

The overall 5-year survival for ovarian cancer is 46%, as a result of late diagnosis …

Cell Cycle Regulation Of Retinal Progenitors; A Role For The Nance-Horan Syndrome Protein In Retinogenesis, Paul J. Vorster

Theses and Dissertations

The Nance-Horan syndrome gene (NHS) plays a role in lens, eye and brain development. To date, the function of NHS remains unclear. Recent evidence showed that p53 isoform, Δ113p53, inhibits abnormal cell growth during organogenesis. We show that NHS is expressed in the retinas of Danio rerio and Xenopus tropicalis during key stages of retinogenesis, and that knockdown of the gene resulted in a small eye phenotype in both species. Initially, knockdown of nhsb in zebrafish had no visible defects at 24hpf. But examination of the retina at 48hpf, we see a marked difference in size compared to control embryos. …

Rheb Dynamics On Lysosomal Membranes Determines Mtorc1 Activity After Loss Of P53 Or Activation Of Ampk, Catherine M. Bell

Theses and Dissertations

The tumor suppressor TP53 is the most frequently altered gene in human cancers. The growth-promoting complex, mTORC1 plays a part of the oncogenic profile caused by dysfunctional p53. mTORC1 sits downstream of AMPK and other crucial tumor suppressors/oncogenes, PTEN, LKB1, and Akt. The antifolate pemetrexed was found by this laboratory to activate AMPK via the inhibition of the enzyme AICART in de novo purine synthesis. This work presents a mechanism of mTORC1 activation with p53 loss, as well as of mTORC1 inhibition by pemetrexed-induced AMPK. We have found that mTORC1 activity was substantially upregulated by the loss …

Investigation Of Gain-Of-Function Induced By Mutant P53, Catherine Vaughan

Theses and Dissertations

p53 is mutated in 50% of all human cancers, and up to 70% of lung cancer. Mutant p53 is usually expressed at elevated levels in cancer cells and has been correlated with a poor prognosis. Cancer cells that express mutant p53 show an increase in oncogenic phenotypes including an increase in growth rate, resistance to chemotherapeutic drugs, and an increase in motility and tumorigenicity to name a few. We have identified several genes involved in cell growth and survival that are upregulated by expression of common p53 mutants: NFκB2, Axl, and epidermal growth factor receptor (EGFR). The aim of this …

Pemetrexed, A Modulator Of Amp-Activated Kinase Signaling And An Inhibitor Of Wild Type And Mutant P53, Stuti Agarwal

Theses and Dissertations

New drug discoveries and new approaches towards diagnosis and treatment have improved cancer therapeutics remarkably. One of the most influential and effective discoveries in the field of cancer therapeutics was antimetabolites, such as the antifolates. The interest in antifolates increased as some of the antifolates showed responses in cancers, such as mesothelioma, leukemia, and breast cancers. When pemetrexed (PTX) was discovered, our laboratory had established that the primary mechanism of action of pemetrexed is to inhibit thymidylate 22 synthase (TS) (E. Taylor et al., 1992). Preclinical studies have shown that PTX has a broad range of antitumor activity in human …