Role of P53 in the Cell Cycle Data Point Educator Materials
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DNA Damage Checkpoint Dynamics Drive Cell Cycle Phase Transitions
bioRxiv preprint doi: https://doi.org/10.1101/137307; this version posted August 4, 2017. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY 4.0 International license. DNA damage checkpoint dynamics drive cell cycle phase transitions Hui Xiao Chao1,2, Cere E. Poovey1, Ashley A. Privette1, Gavin D. Grant3,4, Hui Yan Chao1, Jeanette G. Cook3,4, and Jeremy E. Purvis1,2,4,† 1Department of Genetics 2Curriculum for Bioinformatics and Computational Biology 3Department of Biochemistry and Biophysics 4Lineberger Comprehensive Cancer Center University of North Carolina, Chapel Hill 120 Mason Farm Road Chapel Hill, NC 27599-7264 †Corresponding Author: Jeremy Purvis Genetic Medicine Building 5061, CB#7264 120 Mason Farm Road Chapel Hill, NC 27599-7264 [email protected] ABSTRACT DNA damage checkpoints are cellular mechanisms that protect the integrity of the genome during cell cycle progression. In response to genotoxic stress, these checkpoints halt cell cycle progression until the damage is repaired, allowing cells enough time to recover from damage before resuming normal proliferation. Here, we investigate the temporal dynamics of DNA damage checkpoints in individual proliferating cells by observing cell cycle phase transitions following acute DNA damage. We find that in gap phases (G1 and G2), DNA damage triggers an abrupt halt to cell cycle progression in which the duration of arrest correlates with the severity of damage. However, cells that have already progressed beyond a proposed “commitment point” within a given cell cycle phase readily transition to the next phase, revealing a relaxation of checkpoint stringency during later stages of certain cell cycle phases. -
Cyclin-Dependent Kinase 5 Decreases in Gastric Cancer and Its
Published OnlineFirst January 21, 2015; DOI: 10.1158/1078-0432.CCR-14-1950 Biology of Human Tumors Clinical Cancer Research Cyclin-Dependent Kinase 5 Decreases in Gastric Cancer and Its Nuclear Accumulation Suppresses Gastric Tumorigenesis Longlong Cao1,2, Jiechao Zhou2, Junrong Zhang1,2, Sijin Wu3, Xintao Yang1,2, Xin Zhao2, Huifang Li2, Ming Luo1, Qian Yu1, Guangtan Lin1, Huizhong Lin1, Jianwei Xie1, Ping Li1, Xiaoqing Hu3, Chaohui Zheng1, Guojun Bu2, Yun-wu Zhang2,4, Huaxi Xu2,4,5, Yongliang Yang3, Changming Huang1, and Jie Zhang2,4 Abstract Purpose: As a cyclin-independent atypical CDK, the role of correlated with the severity of gastric cancer based on tumor CDK5 in regulating cell proliferation in gastric cancer remains and lymph node metastasis and patient 5-year fatality rate. unknown. Nuclear localization of CDK5 was found to be significantly Experimental Design: Expression of CDK5 in gastric tumor decreased in tumor tissues and gastric cancer cell lines, and paired adjacent noncancerous tissues from 437 patients was whereas exogenously expression of nucleus-targeted CDK5 measured by Western blotting, immunohistochemistry, and real- inhibited the proliferation and xenograft implantation of time PCR. The subcellular translocation of CDK5 was monitored gastric cancer cells. Treatment with the small molecule during gastric cancer cell proliferation. The role of nuclear CDK5 NS-0011, which increases CDK5 accumulation in the nucleus, in gastric cancer tumorigenic proliferation and ex vivo xenografts suppressed both cancer cell proliferation and xenograft was explored. Furthermore, by screening for compounds in the tumorigenesis. PubChem database that disrupt CDK5 association with its nu- Conclusions: Our results suggest that low CDK5 expression is clear export facilitator, we identified a small molecular (NS-0011) associated with poor overall survival in patients with gastric that inhibits gastric cancer cell growth. -
Mitosis Vs. Meiosis
Mitosis vs. Meiosis In order for organisms to continue growing and/or replace cells that are dead or beyond repair, cells must replicate, or make identical copies of themselves. In order to do this and maintain the proper number of chromosomes, the cells of eukaryotes must undergo mitosis to divide up their DNA. The dividing of the DNA ensures that both the “old” cell (parent cell) and the “new” cells (daughter cells) have the same genetic makeup and both will be diploid, or containing the same number of chromosomes as the parent cell. For reproduction of an organism to occur, the original parent cell will undergo Meiosis to create 4 new daughter cells with a slightly different genetic makeup in order to ensure genetic diversity when fertilization occurs. The four daughter cells will be haploid, or containing half the number of chromosomes as the parent cell. The difference between the two processes is that mitosis occurs in non-reproductive cells, or somatic cells, and meiosis occurs in the cells that participate in sexual reproduction, or germ cells. The Somatic Cell Cycle (Mitosis) The somatic cell cycle consists of 3 phases: interphase, m phase, and cytokinesis. 1. Interphase: Interphase is considered the non-dividing phase of the cell cycle. It is not a part of the actual process of mitosis, but it readies the cell for mitosis. It is made up of 3 sub-phases: • G1 Phase: In G1, the cell is growing. In most organisms, the majority of the cell’s life span is spent in G1. • S Phase: In each human somatic cell, there are 23 pairs of chromosomes; one chromosome comes from the mother and one comes from the father. -
Kinetochores, Microtubules, and Spindle Assembly Checkpoint
Review Joined at the hip: kinetochores, microtubules, and spindle assembly checkpoint signaling 1 1,2,3 Carlos Sacristan and Geert J.P.L. Kops 1 Molecular Cancer Research, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands 2 Center for Molecular Medicine, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands 3 Cancer Genomics Netherlands, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands Error-free chromosome segregation relies on stable and cell division. The messenger is the SAC (also known as connections between kinetochores and spindle microtu- the mitotic checkpoint) (Figure 1). bules. The spindle assembly checkpoint (SAC) monitors The transition to anaphase is triggered by the E3 ubiqui- such connections and relays their absence to the cell tin ligase APC/C, which tags inhibitors of mitotic exit cycle machinery to delay cell division. The molecular (CYCLIN B) and of sister chromatid disjunction (SECURIN) network at kinetochores that is responsible for microtu- for proteasomal degradation [2]. The SAC has a one-track bule binding is integrated with the core components mind, inhibiting APC/C as long as incorrectly attached of the SAC signaling system. Molecular-mechanistic chromosomes persist. It goes about this in the most straight- understanding of how the SAC is coupled to the kineto- forward way possible: it assembles a direct and diffusible chore–microtubule interface has advanced significantly inhibitor of APC/C at kinetochores that are not connected in recent years. The latest insights not only provide a to spindle microtubules. This inhibitor is named the striking view of the dynamics and regulation of SAC mitotic checkpoint complex (MCC) (Figure 1). -
The Cell Cycle & Mitosis
The Cell Cycle & Mitosis Cell Growth The Cell Cycle is G1 phase ___________________________________ _______________________________ During the Cell Cycle, a cell ___________________________________ ___________________________________ Anaphase Cell Division ___________________________________ Mitosis M phase M ___________________________________ S phase replication DNA Interphase Interphase is ___________________________ ___________________________________ G2 phase Interphase is divided into three phases: ___, ___, & ___ G1 Phase S Phase G2 Phase The G1 phase is a period of The S phase replicates During the G2 phase, many of activity in which cells _______ ________________and the organelles and molecules ____________________ synthesizes _______ molecules. required for ____________ __________ Cells will When DNA replication is ___________________ _______________ and completed, _____________ When G2 is completed, the cell is synthesize new ___________ ____________________ ready to enter the ____________________ ____________________ ____________________ ____________________ ____________________ Mitosis are divided into four phases: _____________, ______________, _____________, & _____________ Below are cells in two different phases of the cell cycle, fill in the blanks using the word bank: Chromatin Nuclear Envelope Chromosome Sister Chromatids Nucleolus Spinder Fiber Centrosome Centrioles 5.._________ 1.__________ v 6..__________ 2.__________ 7.__________ 3.__________ 8..__________ 4.__________ v The Cell Cycle & Mitosis Microscope Lab: -
Cell Life Cycle and Reproduction the Cell Cycle (Cell-Division Cycle), Is a Series of Events That Take Place in a Cell Leading to Its Division and Duplication
Cell Life Cycle and Reproduction The cell cycle (cell-division cycle), is a series of events that take place in a cell leading to its division and duplication. The main phases of the cell cycle are interphase, nuclear division, and cytokinesis. Cell division produces two daughter cells. In cells without a nucleus (prokaryotic), the cell cycle occurs via binary fission. Interphase Gap1(G1)- Cells increase in size. The G1checkpointcontrol mechanism ensures that everything is ready for DNA synthesis. Synthesis(S)- DNA replication occurs during this phase. DNA Replication The process in which DNA makes a duplicate copy of itself. Semiconservative Replication The process in which the DNA molecule uncoils and separates into two strands. Each original strand becomes a template on which a new strand is constructed, resulting in two DNA molecules identical to the original DNA molecule. Gap 2(G2)- The cell continues to grow. The G2checkpointcontrol mechanism ensures that everything is ready to enter the M (mitosis) phase and divide. Mitotic(M) refers to the division of the nucleus. Cell growth stops at this stage and cellular energy is focused on the orderly division into daughter cells. A checkpoint in the middle of mitosis (Metaphase Checkpoint) ensures that the cell is ready to complete cell division. The final event is cytokinesis, in which the cytoplasm divides and the single parent cell splits into two daughter cells. Reproduction Cellular reproduction is a process by which cells duplicate their contents and then divide to yield multiple cells with similar, if not duplicate, contents. Mitosis Mitosis- nuclear division resulting in the production of two somatic cells having the same genetic complement (genetically identical) as the original cell. -
Human P14arf-Mediated Cell Cycle Arrest Strictly Depends on Intact P53 Signaling Pathways
Oncogene (2002) 21, 3207 ± 3212 ã 2002 Nature Publishing Group All rights reserved 0950 ± 9232/02 $25.00 www.nature.com/onc Human p14ARF-mediated cell cycle arrest strictly depends on intact p53 signaling pathways H Oliver Weber1,2, Temesgen Samuel1,3, Pia Rauch1 and Jens Oliver Funk*,1 1Laboratory of Molecular Tumor Biology, Department of Dermatology, University of Erlangen-Nuremberg, 91052 Erlangen, Germany; 2Regulation of Cell Growth Laboratory, National Cancer Institute, Frederick, Maryland, MD 21702-1201, USA The tumor suppressor ARF is transcribed from the INK4a/ 4 and 6 activities, thus leading to decreased phosphor- ARF locus in partly overlapping reading frames with the ylation of RB and to G1 arrest. Cells that are de®cient CDK inhibitor p16Ink4a. ARF is able to antagonize the for RB are resistant to p16Ink4a-mediated cell cycle MDM2-mediated ubiquitination and degradation of p53, arrest (Sherr and Roberts, 1995; Weinberg, 1995). leading to either cell cycle arrest or apoptosis, depending on ARF is also a cell cyle inhibitor. It does not directly the cellular context. However, recent data point to inhibit CDKs but interferes with the function of additional p53-independent functions of mouse p19ARF. MDM2 to destabilize p53. ARF may be activated by Little is known about the dependency of human p14ARF aberrant activation of oncoproteins such as Ras function on p53 and its downstream genes. Therefore, we (Palmero et al., 1998), c-myc (Zindy et al., 1998), analysed the mechanism of p14ARF-induced cell cycle arrest E1A (de Stanchina et al., 1998), Abl (Radfar et al., in several human cell types. -
Cell Division for Growth of Eukaryotic Organisms and Replacement of Some Eukaryotic Cells
Mitosis CELL DIVISION FOR GROWTH OF EUKARYOTIC ORGANISMS AND REPLACEMENT OF SOME EUKARYOTIC CELLS T H I S WORK IS LICENSED UNDER A CREATIVE COMMONS ATTRIBUTION - NONCOMMERCIAL - SHAREALIKE 4 . 0 INTERNATIONAL LICENSE . History of Understanding Cancer Rudolf Virchow (1821-1902) – First to recognize leukemia in mid-1800s, believing that diseased tissue was caused by a breakdown within the cell and not from an invasion of foreign organisms. Louis Pasteur (1822-1895) – Proved Virchow to be correct in late 1800s. Virchow’s understanding that cancer cells start out normal and then become abnormal is still used today. If cancer is the study of abnormal cell division, let’s look at normal cell division. Types of Normal Cell Division There are two types of normal cell division – mitosis and meiosis. Mitosis is cell division which begins in the fertilized egg (or zygote) stage and continues during the life of the organism in one way or another. Each diploid (2n) daughter cell is genetically identical to the diploid (2n) parent cell. Meiosis is cell division in the ovaries of the female and testes of the male and involves the formation of egg and sperm cells, respectively. Each diploid (2n) parent cell produces haploid (n) daughter cells. Meiosis will be discussed more fully in Chapter 5 of the Oncofertility Curriculum. Walther Flemming (1843 – 1905) • Described the process of cell division in 1882 and coined the word ‘mitosis’ • Also responsible for the word “chromosome’ which he first referred to as stained strands • Co-worker Eduard Strasburger -
Role of the P53 Tumor Suppressor Gene in Cell Cycle Arrest and Radiosensitivity of Burkitt's Lymphoma Cell Lines
ICANÅ’RRBSIÃŒARCII53.4776^t7so,Octoberis.ITO] Advances in Brief Role of the p53 Tumor Suppressor Gene in Cell Cycle Arrest and Radiosensitivity of Burkitt's Lymphoma Cell Lines Patrick M. O'Connor,1 Joany Jackman, Daniel Jondle, Kishor Bhatia, Ian Magrath, and Kurt W. Kohn Laboratory of Molecular Pharmacology, Developmental Thcra[>eulic.ïProgram, Division of Cancer Treatment ¡P.M. ()., J. J., D. J., K. W. A'./, and Lymphoiil Biology Section, Pediatrics Branch /K. B., I. M./, National Cancer Institute, N1H, Rethesda, Maryland 20892 Abstract ization. Several lines of evidence suggest that p53 functions by bind ing to DNA as an oligomer. Also, cells heterozygous for p53 form We have assessed the role of the p5ÃŒtumorsuppressor gene in cell cycle heterooligomeric complexes (mutant/wild-type p53 complexes), in arrest and cytotoxicity of ionizing radiation in 17 Burkitt's lymphoma and which the ability of the wild-type protein to function is suppressed Ivmphoblastoid cell lines. Cell cycle arrest was assessed by flow cytometry of cells 16 h following irradiation. In addition to the usual G2 arrest, the (11). It appears that the p53 protein is not required for normal mouse cell lines exhibited three types of responses in I.,: Class I, strong arrest in development since transgenic mice lacking both p53 genes are born G i following radiation; Class II, minimal arrest; and Class III, an inter normal (12). Nonetheless, knockout mice and mice expressing mutant mediate response. All Class I cells contained normal p53 genes. Of the ten p53 alÃeleshave a much higher frequency of developing tumors than lines that showed minimal (., arrest, eight had mutant p53 alÃeles,and two their wild-type counterparts (12, 13). -
Cell Cycle the Cell Cycle Is the Period of Time from the Beginning of One
7/22/2009 As you grow from an infant to an adult, you pass through different stages of your life cycle. • Similarly, a cell passes Cell Cycle through different stages of its life. • The life cycle of a cell is Cells divide to increase their numbers called the cell cycle. through a process of mitosis, which results in two daughter cells with identical sets of chromosomes. The cell cycle is the period of time from The longest stage of the cell cycle is the beginning of one cell division to the called interphase. beginning of the next. • Interphase is the stage It consists of three stages: that occurs in between cell 1. interphase divisions. 2. mitosis • During interphase, the cell 3. cytokinesis grows and develops and performs its functions. Toward the end of interphase (just The second stage of the cell cycle is before the cell begins to divide), the called mitosis (splitting of the nucleus). amount of DNA doubles. • Mitosis is the process in cell division where • Organelles of the cytoplasm (like the nucleus divides mitochondria) also double in number. into two nuclei, each with an identical set of chromosomes. • Mitosis is divided into four phases: prophase, metaphase, anaphase, and telophase. 1 7/22/2009 The shortest stage of the cell cycle is called Mitosis cytokinesis (division of the cytoplasm). • In cytokinesis, the cytoplasm and its organelles divide into two daughter cells. – Each daughter cell contains a nucleus with an identical set of chromosomes. • The two daughter cells then start their own cycles, beginning again with the interphase stage. -
The Dynamics of Cell Cycle Regulation John J
Review Articles The dynamics of cell cycle regulation John J. Tyson,1* Attila Csikasz-Nagy,2,3 and Bela Novak2 Summary polypeptide chains, which then fold into three-dimensional Major events of the cell cycle—DNA synthesis, mito- structures with basic functions as enzymes, motors, channels, sis and cell division—are regulated by a complex net- work of protein interactions that control the activities of cytoskeletal components, etc. At the other end, complex as- cyclin-dependent kinases. The network can be modeled semblages of interacting proteins carry out the fundamental by a set of nonlinear differential equations and its be- chores of life: energy metabolism, biosynthesis, signal trans- havior predicted by numerical simulation. Computer duction, movement, differentiation, and reproduction. The simulations are necessary for detailed quantitative com- triumph of molecular biology of the last half of the twentieth parisons between theory and experiment, but they give little insight into the qualitative dynamics of the control century was to identify and characterize the molecular com- system and how molecular interactions determine the ponents of this machine, epitomized by the complete se- fundamental physiological properties of cell replication. quencing of the human genome. The grand challenge of post- To that end, bifurcation diagrams are a useful analytical genomic cell biology is to assemble these pieces into a working tool, providing new views of the dynamical organization model of a living, responding, reproducing cell; a model that of the cell cycle, the role of checkpoints in assuring the integrity of the genome, and the abnormal regulation gives a reliable account of how the physiological properties of a of cell cycle events in mutants. -
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654 Vol. 1, 654–664, July 2003 Molecular Cancer Research Expression of Cyclin-Dependent Kinase 6, but not Cyclin-Dependent Kinase 4, Alters Morphology of Cultured Mouse Astrocytes Karen K. Ericson, David Krull, Peter Slomiany, and Martha J. Grossel Department of Biology, Connecticut College, New London, CT Abstract mechanism involving the accumulation of the p53 and p130 Disruption of the pRb pathway is a common mechanism growth-suppressing proteins (6), and activation of cdk6 in tumor formation. The D-cyclin-associated kinases, precedes cdk4 activation in T cells (7, 8). Also, differences in cyclin-dependent kinase (cdk) 4 and cdk6, are important subcellular localization of cdk4 and cdk6 and in the timing of regulators of the G1-S phase transition and are elevated nuclear localization have been noted in several cell types by in several types of cancers, including gliomas. To several researchers (9–12). Data from tumor studies also investigate potential functional differences in these suggest differences in these kinases. Cdk4, and not cdk6, is kinases, mouse astrocytes were taken from chimeric specifically targeted in melanoma (13, 14) while cdk6 activity mice and propagated in tissue culture. These multipolar has been found to be elevated in squamous cell carcinomas (15, tissue-culture astrocytes were infected with viruses 16) and neuroblastomas (17) without alteration of cdk4 activity. expressing either cdk4 or cdk6. Interestingly, expression Cumulatively, these data suggest that cdk4 and cdk6 have of cdk6 resulted in a distinct and rapid morphology unique functions that may be cell-type specific, temporally change from multipolar to bipolar. This change was not regulated, or developmentally distinct.