Medicine and Health Sciences Commons^™

Investigating The P53 Tumor-Suppressive Network And The Dynamics/Mechanism Of P53 Loss Of Heterozygosity, Jun Wang

All ETDs from UAB

Tumor suppressor gene TP53 is the most frequently mutated gene across human cancers (~50%). Patients with Li-Fraumeni syndrome (LFS) who carry germline p53 mutations exhibit a diverse spectrum of childhood- and adult-onset malignancies. Despite over 40 years of dedicated studies to understand the role of p53 in tumor prevention, there are still many unanswered questions regarding the underlying mechanisms of p53. Previous studies have supported the notion that p53 exerts its tumor-suppressive function through its transcriptional activities. Therefore, strategies to enhance p53’s functions in tumor suppression via manipulating of downstream target gene activities in cancers show promising. To better investigate …

Identification Of Functional Regulatory Elements In The Human Genome Using Pooled Crispr Screens., Samantha M. Borys, Scott T. Younger

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: Genome-scale pooled CRISPR screens are powerful tools for identifying genetic dependencies across varied cellular processes. The vast majority of CRISPR screens reported to date have focused exclusively on the perturbation of protein-coding gene function. However, protein-coding genes comprise < 2% of the sequence space in the human genome leaving a substantial portion of the genome uninterrogated. Noncoding regions of the genome harbor important regulatory elements (e.g. promoters, enhancers, silencers) that influence cellular processes but high-throughput methods for evaluating their essentiality have yet to be established.

RESULTS: Here, we describe a CRISPR-based screening approach that facilitates the functional profiling of thousands of noncoding regulatory elements in parallel. We selected the tumor suppressor p53 as a model system and designed a pooled CRISPR library targeting thousands of p53 binding sites throughout the genome. Following transduction into dCas9-KRAB-expressing cells we identified several regulatory elements that influence cell proliferation. Moreover, …

Rgs16, A Novel P53 And Prb Cross-Talk Candidate Inhibits Migration And Invasion Of Pancreatic Cancer Cells, Miranda B. Carper, James Denvir, Goran Boskovic, Donald A. Primerano, Pier Paolo Claudio

Pier P. Claudio

Data collected since the discovery of p53 and pRb/RB1 suggests these tumor suppressors cooperate to inhibit tumor progression. Patients who have mutations in both p53 and RB1 genes have increased tumor reoccurrence and decreased survival compared to patients with only one tumor suppressor gene inactivated. It remains unclear how p53 and pRb cooperate toward inhibiting tumorigenesis. Using RNA expression profiling we identified 179 p53 and pRb cross-talk candidates in normal lung fibroblasts (WI38) cells exogenously coexpressing p53 and pRb. Regulator of G protein signaling 16 (RGS16) was among the p53 and pRb cross-talk candidates and has been implicated in inhibiting …

Rgs16, A Novel P53 And Prb Cross-Talk Candidate Inhibits Migration And Invasion Of Pancreatic Cancer Cells, Miranda B. Carper, James Denvir, Goran Boskovic, Donald A. Primerano, Pier Paolo Claudio

Donald A. Primerano

Data collected since the discovery of p53 and pRb/RB1 suggests these tumor suppressors cooperate to inhibit tumor progression. Patients who have mutations in both p53 and RB1 genes have increased tumor reoccurrence and decreased survival compared to patients with only one tumor suppressor gene inactivated. It remains unclear how p53 and pRb cooperate toward inhibiting tumorigenesis. Using RNA expression profiling we identified 179 p53 and pRb cross-talk candidates in normal lung fibroblasts (WI38) cells exogenously coexpressing p53 and pRb. Regulator of G protein signaling 16 (RGS16) was among the p53 and pRb cross-talk candidates and has been implicated in inhibiting …

Rgs16, A Novel P53 And Prb Cross-Talk Candidate Inhibits Migration And Invasion Of Pancreatic Cancer Cells, Miranda B. Carper, James Denvir, Goran Boskovic, Donald A. Primerano, Pier Paolo Claudio

James Denvir

Data collected since the discovery of p53 and pRb/RB1 suggests these tumor suppressors cooperate to inhibit tumor progression. Patients who have mutations in both p53 and RB1 genes have increased tumor reoccurrence and decreased survival compared to patients with only one tumor suppressor gene inactivated. It remains unclear how p53 and pRb cooperate toward inhibiting tumorigenesis. Using RNA expression profiling we identified 179 p53 and pRb cross-talk candidates in normal lung fibroblasts (WI38) cells exogenously coexpressing p53 and pRb. Regulator of G protein signaling 16 (RGS16) was among the p53 and pRb cross-talk candidates and has been implicated in inhibiting …

Nicotinamide N-Methyltransferase Expression And Its Association With Phospho-Akt, P53 Expression, And Survival In High-Grade Endometrial Cancer, Serra Akar, İsmai̇l Harmankaya, Serdar Ugras, Çeti̇n Çeli̇k

Turkish Journal of Medical Sciences

Background/aim: Nicotinamide N-methyltransferase (NNMT) is an enzyme that is overexpressed in malignancies. NNMT expression has not been previously studied in endometrial cancer (EC). Increased phospho-Akt (pAkt) levels in response to NNMT overexpression have been reported in in vitro studies of different cancer types. We assayed NNMT expression in primary and metastatic high-grade EC and investigated the relationship of NNMT with p53, pAkt, and survival. Materials and methods: NNMT, pAkt, and p53 expressions were assayed in 100 tissue samples of benign endometria, primary EC, and metastatic EC by immunohistochemistry. Results: The NNMT immunoreactivity score was significantly higher in primary high-grade EC …

Myricetin Inhibits Proliferation Of Cisplatin-Resistant Cancer Cells Through A P53-Dependent Apoptotic Pathway, Haizhi Huang, Allen Y. Chen, Xingqian Ye, Bingyun Li, Yon Rojanasakul, Gary O. Rankin, Yi Charlie Chen

Gary O. Rankin

Cisplatin is a commonly used drug for cancer treatment by crosslinking DNA, leading to apoptosis of cancer cells, resistance to cisplatin treatment often occurs, leading to relapse. Therefore, there is a need for the development of more effective treatment strategies that can overcome chemoresistance. Myricetin is a flavonoid from fruits and vegetables, showing anticancer activity in various cancer cells. In this study, we found myricetin exhibited greater cytotoxicity than cisplatin in two cisplatin-resistant ovarian cancer cell lines, OVCAR-3 and A2780/CP70, and it was less cytotoxic to the normal ovarian cell line IOSE-364. Myricetin selectively induced apoptosis in both cisplatin-resistant cancer …

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 …

Urokinase Plasminogen Activator Expression Is Regulated By P53 Harboring The Lung Cancer-Specific Mutation V157f, Julie Barta, Md, Kristen Pauley, Steven B. Mcmahon, Phd

Department of Biochemistry and Molecular Biology Posters

OBJECTIVES

• To define the mutant p53-regulated transcriptome of lung cancer cells with alterations at V157 and R158 in the p53 tumor suppressor.
• To determine the biological effects of lung-enriched p53 mutations in lung cancer cells.

Theaflavin-3, 3'-Digallate Induces Apoptosis And G2 Cell Cycle Arrest Through The Akt/Mdm2/P53 Pathway In Cisplatin-Resistant Ovarian Cancer A2780/Cp70 Cells, Youying Tu, Eunhye Kim, Ying Gao, Gary O. Rankin, Bo Li, Yi Charlie Chen

Pharmacology, Physiology and Toxicology

Ovarian cancer is the most lethal gynecological cancer among women worldwide. Adverse side effects and acquired resistance to conventional platinum based chemotherapy are major impediments in ovarian cancer treatment, and drive the development of more selective anticancer drugs that target cancer-specific defects. In this study, theaflavin-3, 3'-digallate (TF3), the major theaflavin monomer in black tea, exhibited a potent growth inhibitory effect on the cisplatinresistant ovarian cancer A2780/CP70 cells (IC50, 23.81 μM), and was less cytotoxic to a normal ovarian IOSE‑364 cells (IC50, 59.58 μM) than to the cancer cells. Flow cytometry analysis indicated that TF3 induced preferential apoptosis and G2 …

Investigating The Regulation And Function Of The Nr4a Nuclear Receptors In Cancer, Jordan A. Beard

Theses and Dissertations (ETD)

The nuclear receptor (NR) superfamily represents a structurally-conserved group of ligand-regulated transcription factors. These proteins have critical roles in various physiological and pathological processes, including cancer, and have been targets of drug therapy. The orphan NR subfamily 4A (NR4A), which includes the NR4A1 (Nur77), NR4A2 (Nurr1), and NR4A3 (Nor-1) genes, has been implicated in adult solid tumors and has been characterized as pro-tumorigenic mediator of cell proliferation, transformation, migration, and drug resistance. Alternatively, in leukemia, NR4A1 and NR4A3 have been described as tumor suppressors in hematologic malignancies. Members of the NR4A family are commonly overexpressed in cancer and this has …

Novel Cellular Targets Of Aspirin In Chemoprevention Studies On P53, G6pd And C-Myc, Guoqiang Ai

Electronic Theses and Dissertations

Background

Aspirin has generated a significant interest in recent years as a potential chemopreventive agent supported by strong evidence from epidemiological data; however, the mechanisms are not well understood. The objective of this dissertation is to identify novel cyclooxygenase (COX)-independent pathways by which aspirin exerts its anticancer effects in epithelial cancer cell lines. We investigated the effect of aspirin on p53, glucose 6-phosphate dehydrogenase (G6PD), and c-Myc, all of which are known to play a major role in cancer development. p53 is a tumor suppressor protein, often mutated in cancers causing its inactivation. Expression of G6PD is elevated in many …

Expression Of Maspin In Testis Tumors With Germ Cells Andits Relation With Angiogenesis Factors, Hüseyi̇n Çeli̇k, Tahsi̇n Turunç, Nebi̇l Bal, Eray Hasirci, Alaaddi̇n Akay, Çeti̇n Levent Peşki̇rci̇oğlu

Turkish Journal of Medical Sciences

Background/aim: We aimed to evaluate the importance of maspin expression in testicular tumors with germ cells, its effect on prognosis, and the relation with angiogenesis factors. Materials and methods: The paraffin blocks of the orchiectomy materials of 32 patients who had undergone orchiectomy due to testicular tumors were taken within the scope of the study. The specimens of the cases included in the study group were reexamined under light microscope. Results: While just one maspin-positive sample was found in the seminoma cases, maspin stained positively in 6 of the nonseminoma germ cell tumors (NSGCTs). No statistical difference was found between …

Myricetin Inhibits Proliferation Of Cisplatin-Resistant Cancer Cells Through A P53-Dependent Apoptotic Pathway, Haizhi Huang, Allen Y. Chen, Xingqian Ye, Bingyun Li, Yon Rojanasakul, Gary O. Rankin, Yi Charlie Chen

Pharmacology, Physiology and Toxicology

Cisplatin is a commonly used drug for cancer treatment by crosslinking DNA, leading to apoptosis of cancer cells, resistance to cisplatin treatment often occurs, leading to relapse. Therefore, there is a need for the development of more effective treatment strategies that can overcome chemoresistance. Myricetin is a flavonoid from fruits and vegetables, showing anticancer activity in various cancer cells. In this study, we found myricetin exhibited greater cytotoxicity than cisplatin in two cisplatin-resistant ovarian cancer cell lines, OVCAR-3 and A2780/CP70, and it was less cytotoxic to the normal ovarian cell line IOSE-364. Myricetin selectively induced apoptosis in both cisplatinresistant cancer …

Myricetin Inhibits Proliferation Of Cisplatin-Resistant Cancer Cells Through A P53-Dependent Apoptotic Pathway, Haizhi Huang, Allen Y. Chen, Xingqian Ye, Bingyun Li, Yon Rojanasakul, Gary O. Rankin, Yi Charlie Chen

Pharmaceutical Science and Research

Cisplatin is a commonly used drug for cancer treatment by crosslinking DNA, leading to apoptosis of cancer cells, resistance to cisplatin treatment often occurs, leading to relapse. Therefore, there is a need for the development of more effective treatment strategies that can overcome chemoresistance. Myricetin is a flavonoid from fruits and vegetables, showing anticancer activity in various cancer cells. In this study, we found myricetin exhibited greater cytotoxicity than cisplatin in two cisplatin-resistant ovarian cancer cell lines, OVCAR-3 and A2780/CP70, and it was less cytotoxic to the normal ovarian cell line IOSE-364. Myricetin selectively induced apoptosis in both cisplatin-resistant cancer …

Clinicopathological Importance Of Ki-67, P27, And P53 Expression In Gastric Cancer, Muhammet Çalik, Eli̇f Demi̇rci̇, Eren Altun, İlknur Çalik, Özge Beyza Gündoğdu, Nesri̇n Gürsan, Betül Gündoğdu, Mevlüt Albayrak

Turkish Journal of Medical Sciences

To assess the prognostic value of Ki-67, p27, and p53 immunoreactivity in human gastric cancer. Materials and methods: A total of 84 patients with gastric cancer participated in our study. We categorized tumors as intestinal and diffuse types, with reference to Lauren's classification. Ki-67, p27, and p53 immunoreactivity were correlated with patient's age, tumor type, grade, lymph node status, extent of invasion, tumor-node-metastasis (TNM) stage, and survival. Results: Decreased expression of p27 (50% positivity of cells) were determined in 41 (48.8%) and 29 (36.9%) tumor specimens, respectively, and were connected with both the TNM stage (P = 0.007 and P …

Determination Of Apoptosis And Cell Cycle Modulators (P16, P21, P27, P53, Bcl-2,Bax, Bcl-Xl, And Cyclin D1) In Thyroid Follicular Carcinoma, Follicular Adenoma,And Adenomatous Nodules Via A Tissue Microarray Method, Peyker Temi̇z, Gi̇zem Akkaş, Nalan Neşe, Fazi̇let Uğur Duman, Cansu Karakaş, Yamaç Erhan

Turkish Journal of Medical Sciences

Background/aim: To identify the role of gene products associated with apoptosis and cell cycle in the pathogenesis of thyroid follicular neoplasm. Materials and methods: Thirty follicular adenomas (FAs), 16 follicular carcinomas (FCs), and 20 adenomatous nodules (ANs) were investigated with immunohistochemical staining of p16, p21, p27, p53, Bcl-2, Bax, Bcl-xL, and cyclin D1 via a tissue microarray method. Results: Bcl-2 showed a significant difference between the benign groups (AN and FA) and the malignant group (FC). Bax was significantly higher in the FC group. p53 was lowest in the AN group and highest in the FC group with significant differences …

Rgs16, A Novel P53 And Prb Cross-Talk Candidate Inhibits Migration And Invasion Of Pancreatic Cancer Cells, Miranda B. Carper, James Denvir, Goran Boskovic, Donald A. Primerano, Pier Paolo Claudio

Biochemistry and Microbiology

Data collected since the discovery of p53 and pRb/RB1 suggests these tumor suppressors cooperate to inhibit tumor progression. Patients who have mutations in both p53 and RB1 genes have increased tumor reoccurrence and decreased survival compared to patients with only one tumor suppressor gene inactivated. It remains unclear how p53 and pRb cooperate toward inhibiting tumorigenesis. Using RNA expression profiling we identified 179 p53 and pRb cross-talk candidates in normal lung fibroblasts (WI38) cells exogenously coexpressing p53 and pRb. Regulator of G protein signaling 16 (RGS16) was among the p53 and pRb cross-talk candidates and has been implicated in inhibiting …

Paracrine Apoptotic Effect Of P53 Mediated By Tumor Suppressor Par-4, Ravshan Burikhanov, Tripti Shrestha-Bhattarai, Nikhil Hebbar, Shirley Qiu, Yanming Zhao, Gerard P. Zambetti, Vivek M. Rangnekar

Radiation Medicine Faculty Publications

The guardian of the genome, p53, is often mutated in cancer and may contribute to therapeutic resistance. Given that p53 is intact and functional in normal tissues, we harnessed its potential to inhibit the growth of p53-deficient cancer cells. Specific activation of p53 in normal fibroblasts selectively induced apoptosis in p53-deficient cancer cells. This paracrine effect was mediated by p53-dependent secretion of the tumor suppressor Par-4. Accordingly, the activation of p53 in normal mice, but not p53⁻/⁻ or Par-4⁻/⁻ mice, caused systemic elevation of Par-4, which induced apoptosis of p53-deficient tumor cells. Mechanistically, p53 …

Isolation And Characterization Of Multipotent Lung Stem Cells From P53 Mutant Mice Models, Venkat Sundar Gadepalli

Theses and Dissertations

Recent advances in understanding lung biology have shown evidence for the existence of resident lung stem cells. Independent studies in identifying and characterizing these somatic lung stem cells have shown the potential role of these cells in lung repair and regeneration. Understanding the functional characteristics of these tissue resident stem/progenitor cells has gained much importance with increasing evidence of cancer stem cells, cells in a tumor tissue with stem cell characteristics. Lung cancer is most commonly characterized by loss of p53 function which results in uncontrolled cell divisions. Incidence of p53 point mutations is highest in lung cancer, with a …

The Expression Of Egfr, Cerbb2, P16, And P53 And Their Relationship With Conventional Parameters In Squamous Cell Carcinoma Of The Larynx, Hülya Şi̇mşek, Ünsal Han, Bi̇nnur Önal, Gülçi̇n Şi̇mşek

Turkish Journal of Medical Sciences

To investigate the expression of epidermal growth factor receptor¬-HER1 (EGFR), cerbB2 (HER2), p16, and p53, as well as the relationship of the expression of these genes with conventional parameters in squamous cell carcinoma (SCC) of the larynx. Materials and methods: Samples from 92 cases of diagnosed laryngeal SCC between 2001 and 2011 from the Pathology Department of Ministry of Health Ankara Dışkapı Yıldırım Beyazıt Teaching & Research Hospital were studied by immunohistochemistry using EGFR, cerbB2, p16, and p53 antibodies. Results: An increase in the TNM stage and pathological tumor size status correlated with an increase in EGFR and cerbB2 expression. …

Cytotoxic Properties Of Novel Platinum Compounds, Bbr3610-Dach And Trans-4-Nbd In Tumor Cells: Cellular Effects Of 1, 2-Dach And Nbd Ligands, Vijay Menon

Theses and Dissertations

Platinum-based chemotherapeutics are used for the treatment of a wide range of cancers and a number of attempts have been made toward developing compounds with better cellular stability and similar or enhanced cytotoxicity as compared to their predecessors. The first part of the work reported here focuses on the cellular effects of the metabolically stable dinuclear platinum compound, BBR3610-DACH. Comet assay showed this compound to form interstrand crosslinks, a highly toxic DNA lesion in HCT116 cells, at equimolar concentrations to its parental compound, BBR3610. Cell cycle studies showed that BBR3610-DACH causes G1/S and G2/M cell cycle arrest with S phase …

Expression Of Cyclin D1, P27, P21, Bcl-2, And P53 In Laryngeal Squamous Cell Carcinoma And An Investigation Of The Correlation With Conventional Prognostic Factors, Gülçi̇n Şi̇mşek, Ünsal Han, Bi̇nnur Önal, Fatma Fulya Köybaşioğlu, İstemi̇han Akin, Muharrem Dağli

Turkish Journal of Medical Sciences

Because it is a multistep process, in carcinogenesis it is necessary to determine key genes such as cyclin D1, p27, p21, bcl-2, and p53 that are responsible for uncontrolled proliferation and other mechanisms. The aim of this study was to examine the correlation between the anomalous accumulation of these proteins and the prognosis of laryngeal carcinomas. Materials and methods: In our study, cyclin D1, p27, p21, bcl-2, and p53 expressions were analyzed immunohistochemically in laryngeal squamous cell carcinomas, and the findings were compared with conventional prognostic parameters such as patient age, sex, tumor localization and diameter, tumor differentiation, lymph node …

Characterization Of Beryllium As A Novel Agent To Study Cell Cycle Arrest And Cellular Senescence, Priyatham Gorjala

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cancer cells evade senescence, apoptosis, and other constraints on proliferation, often via mutation of the p53 tumor suppressor gene (TP53). Normal human lung fibroblasts have been shown to enter premature senescence upon exposure to beryllium. In these cells, BeSO₄ stabilizes p53 protein, increases p21 gene expression, induces senescence-associated β-galactosidase activity and causes cell proliferation arrest. In the present study, we have investigated whether BeSO₄ is able to induce similar effects in cancer cells that have wildtype p53. We have demonstrated that beryllium salt at low concentration can induce molecular changes in the p53 signaling pathway leading to cell …

Dna Damage And Oxidative Stress Induced-P53 Activity In Astrocytes Causes Growth Arrest, Sarah A. Humphrey

Electronic Thesis and Dissertation Repository

An increasing body of evidence suggests that astrocytes play a key role in modulating neuronal fate during acute and chronic neurodegenerative conditions. Following CNS injury, an upregulation of p53 has been noted in both neurons and reactive astrocytes. p53 is an extremely important protein in determining cell fate decisions and its activation can result in the transcriptional induction of target genes that regulate apoptosis, autophagy, senescence and cell-cycle arrest. We found that p53 is upregulated in primary cortical astrocytes following oxidative stress and DNA damage and that this upregulation results in the p53-dependent transcriptional induction of several target genes involved …

Is P53 A Target Of Hpv-18 E6 In The Viral Life Cycle?, Eun-Young Kho

All ETDs from UAB

The large family of human papillomaviruses (HPVs) infects the cutaneous or mucosal epithelia causing benign hyper proliferative diseases. Infections by the high-risk (HR) HPV genotypes in the anogenital tracts can progress to high grade lesions and cancers in men and women. Because the viral productive program requires squamous differentiation of epithelia, HPV encodes oncoproteins that recondition the differentiated cells that have withdrawn from the cell cycle to support viral DNA amplification. The HR HPV E6 and E7 oncogenes are selectively expressed in cervical carcinomas and are necessary to maintain the malignant state. In vitro, constitutive expression of the HR HPV …

Creation Of Multilinage Adult Stem-Like Cells From Terminally Differentiatied Fibroblasts, John Moore

Theses and Dissertations

Induced Pluripotent Stem cells (iPScs) are artificially generated cells that demonstrate multilineage differentiation potential. These cells demonstrate similar morphology and high differentiation potential to Embryonic Stem Cells (ESCs). Generation of these cells from a terminally differentiated cell line requires activation of the core pluripotency genes Nanog, Oct4, and Sox2 as well as an oncogenic stimulus such as c-Myc. Here we examine the effect of the Human Pappiloma Virus derived proteins E6 and E7 on the ability of a terminally differentiated fibroblast cell line to a more primitive state and examine its multilineage differentiation capacity. In this paper, we attempt to …

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 …

Involvement Of P53 In The S-Phase Checkpoint During Nucleotide Deficiencies, Cortney Heyer

Theses and Dissertations

Several classes of antimetabolites have been developed for the treatment of cancer, including numerous inhibitors of nucleotide biosynthesis. N-(phosphonacetyl)-L-aspartate (PALA) and hydroxyurea (HU) are two antimetabolites that inhibit nucleotide biosynthesis; PALA inhibits de novo pyrimidine synthesis and HU inhibits the conversion of ribonucleotide diphosphates to deoxyribonucleotide diphosphates. Due to the similar mechanisms, it was thought that cancer cells would respond similarly to HU and PALA treatment. However, studies in this dissertation revealed strikingly different responses to either HU or PALA treatment in HCT116 cells. A cytoprotective S-phase arrest was activated upon HU treatment while PALA treatment failed to activate the …

The Effects Of P53 Inhibition Using Pifithrin-Α On Acute Necrotizing Pancreatitis In Rats, Etem Alhan, Aki̇f Ci̇nel, Mehmet Cengi̇z Erçi̇n, Serdar Türkyilmaz, Bi̇rgül Vani̇zor Kural, Murat Alper, Deni̇z Fi̇li̇nte

Turkish Journal of Medical Sciences

To investigate the effects of p53 inhibition using pifithrin-\alpha (PFA) on acute necrotizing pancreatitis (ANP) induced by glycodeoxycholic acid in rats. The role of p53 during acute pancreatitis is unclear. Materials and methods: Rats were divided into 4 groups, 2 of which were initially given only saline (the sham group) and 2 of which were given glycodeoxycholic acid in order to induce ANP. Each group was then identified according to treatment plan: sham+saline, sham+PFA, ANP+saline, or ANP+PFA. The study then investigated the extent of acinar cell injury, apoptosis, mortality, systemic cardiorespiratory variables, functional capillary density (FCD), renal/hepatic functions, and changes …