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Ionizing radiation DNA damage repair

In this article, we discuss some of the different types of DNA damage induced by ionizing radiation, including modified bases, sugar damage, strand breaks, and clustered DNA damage. This will be followed by a description of some of the basic mechanisms the cell uses to repair ionizing radiation-induced DNA damage, such as base excision repair DNA repair after ionizing radiation Ionizing radiation causes DSBs directly, but in addition base damages due to indirect effects are also induced. This radiation causes formation of ROS (reactive oxygen species) which are indirectly involved in DNA damage. These ROS generates apurinic Among these proteins are Rad51 and Mre11, which are known to re-localize to sites of DNA damage into nuclear foci. Ionizing radiation-induced foci can be visualized by immuno-staining. Published data show a large variation in the number of foci-positive cells and number of foci per nucleus for specific DNA repair proteins Significance: Ionizing radiation (IR) is an effective and commonly employed treatment in the management of more than half of human malignancies. Because IR's ability to control tumors mainly relies on DNA damage, the cell's DNA damage response and repair (DRR) processes may hold the key to determining tumor responses Ionizing Radiation-Induced DNA damage repair Yu, Xiaochun Beckman Research Institute/City of Hope, Duarte, CA, United States In this proposal, we plan to examine the mechanism by which NADP+ participates in DNA damage repair, and if NADP+ can serve as a biomarker and a sensitizer for cancer therapy including chemotherapy and radiation therapy

DNA damage in mammalian chromatin in vitro and in cultured mammalian cells including human cells was studied. In the first phase of these studies, a cell culture laboratory was established. Necessary equipment including an incubator, a sterile laminar flow hood and several centrifuges was purchased. We have successfully grown several cell lines such as murine hybridoma cells, V79 cells and. EFFECTS OF LOW DOSE IONIZING RADIATION ON DNA DAMAGE AND REPAIR RESPONSE IN PROLIFERATING MUSCLE STEM CELLS By OLUWASEUN ODEBUNMI Thesis submitted to the University of Ottawa in partial fulfillment of the requirements for the degree of Master of Science Department of Biochemistry, Microbiology and Immunology, Faculty of Medicin Ionizing radiation induces different types of damage in DNA. The most common by far is oxidation and fragmentation of DNA bases, and the MMR system is involved in processing 8-oxoguanosines (GOs)..

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Repair of DNA Damage Produced by Ionizing Radiation: A

  1. Ionizing radiation (IR)‐based therapy causes DNA damage, exerting a curative effect; however, DNA damage repair signaling pathways lead to HCC resistance to IR‐based therapy
  2. In this context, RAD51 is one such protein that assists in the repair of DNA double strand breaks (DSBs) which are induced by ionizing radiation and is also highly conserved from yeast to humans (Thacker, 2005)
  3. DNA double-strand breaks (DSBs) are the most deleterious of all DNA lesions generated either directly following exposure to ionizing radiation or indirectly, for instance through the processing of other DNA lesions. In cells, specific protein signalling networks sense DSBs, arrest the cell cycle and activate the DSB DNA repair pathways (7)
  4. When ionizing radiation interacts with a cell, several things can happen: The radiation could pass through the cell without damaging the DNA. The radiation could damage the cell's DNA, but the DNA repairs itself. The radiation could prevent the DNA from replicating correctly
  5. The idea that cells might readily learn to more efficiently and reliably repair DNA damage after repeated exposures to low-level ionizing radiation is not supported by the available data. Advocates of hormesis suggest that upregulation of the repair systems would not only facilitate repair of the current injury but also provide protection.

Ionizing radiation-induced DNA injury and damage detection

Radiation, an international, peer-reviewed Open Access journal. Dear Colleagues, In this Special Issue, we would like to invite groups working on the role(s) of DNA damage and its repair induced by ionizing radiations as instigators of the full range of biological responses to radiation DNA double-strand breaks constitute the most dangerous type of DNA damage induced by ionising radiation (IR). Accordingly, the resistance of cells to IR is modulated by three intimately related..

Analysis of ionizing radiation-induced foci of DNA damage

Ionizing Radiation-Induced DNA Damage, Response, and Repai

The combination of ionizing radiation with inhibitors of DNA damage responses increases the accumulation of DNA damage in cancer cells, which facilitates their antitumor effect, a process regulated by VRK1 1 INTRODUCTION. Monte Carlo (MC)-based algorithms are well established as the gold standard in the field of radiation transport and dosimetry, radiobiology, and DNA damage scoring. 1 Based on physics and chemistry models, MC simulations can predict with high accuracy the deposited energy by a charged particle, as well as the DNA damage, using probabilistic methods while keeping track of time. OSTI.GOV Journal Article: Models for DNA damage formation and repair in mammalian cells exposed to ionizing radiation. Models for DNA damage formation and repair in mammalian cells exposed to ionizing radiation. Full Record Cells can repair this damage enzymatically. Our goal is to characterize and modify the cellular bioreductive repair system for DNA hydroperoxide. This could be exploited to increase the efficacy of radiation therapy to tumor cells. The objectives of the current work are: (1) To synthesize and quantitate hydroperoxide substrates of DNA

Ionizing Radiation-Induced DNA damage repair - Xiaochun Y

  1. @article{osti_807355, title = {Repair of DNA damaged by ionizing radiation and other oxidative agents in yeast and human}, author = {Prakash, Louisek}, abstractNote = {OAK B202 Treatment of cells with oxidative DNA damaging agents such as ionizing radiation and hydrogen peroxide produces .OH radicals which attack DNA, producing single strand breaks and double strand breaks that have a 3.
  2. us with a phosphoglycolate or a phosphate group attached to the 3'-ter
  3. Formation and Repair of Complex DNA Damage Induced by Ionizing Radiation 4 ABSTRACT DNA is the critical target when cells are exposed to ionizing radiation, a potent stressor with capacity to produce complex DNA damages, thereby increasing the risk of cancer. DNA an
  4. MicroRNA 34a promotes ionizing radiation-induced DNA damage repair in murine hematopoietic stem cells Hao Zeng,1 Mengjia Hu,1 Yukai Lu, Zihao Zhang, Yang Xu, Song Wang, Mo Chen, Mingqiang Shen, Cheng Wang, Fang Chen, Changhong Du, Yong Tang, Yongping Su, Shilei Chen,2 and Junping Wang
  5. Ionizing radiation such as that created by radioactive decay or in cosmic rays causes breaks in DNA strands (Figure 12.10a). Low-level ionizing radiation may induce irreparable DNA damage (leading to replicational and transcriptional errors needed for neoplasia or may trigger viral interactions) leading to premature aging and cancer
  6. Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date.
  7. or groove-binding small molecules. We hypothesized that Py-Im polyamides can modulate the cellular response to ionizing radiation. Pre-treatment of cells with a Py-Im polyamide prior to exposure to ionizing radiation resulted in a delay in resolution of phosphorylated γ-H2AX foci, increase in XRCC1 foci, and reduced.

Ionizing Radiation-Associated DNA Damage, Radiotherapy and Mechanisms of DNA Repair Ionizing radiation effects in the cell Ionizing radiation is a type of high-energy radiation that is able to release electrons from atoms and molecules generating ions which can break covalent bonds Ionizing radiation (IR)‐based therapy causes DNA damage, exerting a curative effect; however, DNA damage repair signaling pathways lead to HCC resistance to IR‐based therapy. RAD21 is a component of the cohesion complex, crucial for chromosome segregation and DNA damage repair, while it is still unclear whether RAD21 is implicated in DNA. Double-strand breaks (DSB): induced by ionizing radiation, transposons, topoisomerases, homing endonucleases, and mechanical stress on chromosomes Repair of UV-induced dimers in the light Photoreactivation Light-dependent, UV-A blue light (360-420 nm) Catalyzed by Photolyases: Enzymes that convert the dimers to monomers Use FAD as chromophore. NELSON, S. J. Models for DNA Damage Formation and Repair in Mammalian Cells Exposed to Ionizing Radiation. Radiat. Res. 92, 120-145 (1982). As the first stage in the development of a comprehensive explanation of radiation effects in mammalian cells, a general model for DNA damage formation and repair is described. This applies to events in. Repair of DNA double-strand breaks by homologous recombination requires an extensive set of proteins. Among these proteins are Rad51 and Mre11, which are known to re-localize to sites of DNA damage into nuclear foci. Ionizing radiation-induced foci can be visualized by immuno-staining. Published data show a large variation in the number of foci.

Cells can repair this damage enzymatically. Our goal is to characterize and modify the cellular bioreductive repair system for DNA hydroperoxide. This could be exploited to increase the efficacy of radiation therapy to tumor cells. The objectives of the current work are: (1) To synthesize and quantitate hydroperoxide substrates of DNA Fingerprint Dive into the research topics of 'Radiation dose does matter: Mechanistic insights into DNA damage and repair support the linear no-threshold model of low-dose radiation health risks'. Together they form a unique fingerprint. DNA Repair Medicine & Life Science The repair of mixed radiation-induced complex DNA damage is poorly understood (9, 12).The mechanism defining which repair pathway is selected is not clear; however, the cell cycle or an inducing factor may be responsible (9, 32, 33).NHEJ acts mainly in G1 and early S phase, with no need for an undamaged DNA template to operate, while HRR operates in the S phase using sister chromatid as the.

Ionizing Radiation-Induced DNA Damage and Its Repair in

Ionizing radiation induces DNA double stand breaks, which activates a signal cascade initiated by ATM/ATR kinases. The damage signals stop the cell cycle progression and allow enough time for DNA dama.. DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA damage, resulting in tens of thousands of individual molecular lesions per cell per day. Many of these lesions cause structural damage to the DNA molecule. in plants is scanty and unsubstantiated. However, the DNA damage under UV radiation and DNA repair associated enzymes have been shown to greatly modulate the mutation rate, chromosome aberration frequencies, and viability in seedsandseedlings[ ]. e following sections and subsections present an overview on UV/ionizing radiation-mediated DNA dam

Is mismatch repair really required for ionizing radiation

A similar distinction can be made for ionizing radiation damage processing by MMR versus BER, although nonhomologous end joining and homologous recombination are felt to be the major ionizing radiation repair pathways for double-strand breaks, which are the most lethal type of ionizing radiation-DNA damage (22, 23) Radiation-induced growth delay and DNA damage. Previous experiments indicated that P. abyssi cells were able to fully recover growth within 2 h after gamma-ray irradiation at 2,500 Gy under optimal growth conditions in YPS medium (data not shown), suggesting that irradiated cells efficiently repaired massive DNA damage within this repair period ()

In this study, we show that the expression of miRNA 34a (miR-34a) is markedly up-regulated in HSCs from mice subjected to ionizing radiation (IR). Reduced numbers and DNA damage repair, as well as increased apoptosis, are observed in HSCs from miR-34a-deficient mice induced by irradiation, although miR-34a is dispensable for steady-state. The VRK1 chromatin kinase regulates the organization of locally altered chromatin induced by DNA damage. The combination of ionizing radiation with inhibitors of DNA damage responses increases the accumulation of DNA damage in cancer cells, which facilitates their antitumor effect, a process regulated by VRK1. Tumor cell lines with different genetic backgrounds were treated with olaparib to. Radiation is one of the causative agents for the induction of DNA damage in biological systems. There is various possibility of radiation exposure that might be natural, man-made, intentional, or non-intentional. Published literature indicates that radiation mediated cell death is primarily due to DNA damage that could be a single-strand break, double-strand breaks, base modification, DNA. Torin2 suppresses ionizing radiation-induced DNA damage repair. Durga Udayakumar *, Raj K. Pandita, Nobuo Horikoshi, Yan Liu, Qingsong Liu, Kwok Kin Wong, Clayton R. Hunt, Nathanael S. Gray, John D. Minna, Tej K. Pandita, Kenneth D. Westover * Corresponding author for this work. Radiation Oncology; Research output: Contribution to journal. Specialty section: Keywords: DNA damage, oxidative stress, biomarkers, ionizing radiation, UV radiation, clustered DNA lesions This article was submitted to Chemical Biology, a section of the journal Frontiers in Chemistry Introduction Received: 23 January 2015 DNA Damage Formation and Consequences also Including DNA Repair Accepted: 07 May.

MiR‐320b/RAD21 axis affects hepatocellular carcinoma

Vens, C., Hofland, I. and Begg, A. C. Involvement of DNA Polymerase Beta in Repair of Ionizing Radiation Damage as Measured by In Vitro Plasmid Assays. Radiat. Res. 168, 281- 291 (2007).Characteristic of damage introduced in DNA by ionizing radiation is the induction of a wide range of lesions. Single-strand breaks (SSBs) and base damages outnumber double-strand breaks (DSBs). If unrepaired. We used a single-cell alkaline gel electrophoresis (SCAGE) assay to study repair of primarily single-stranded DNA breaks after in vitro exposure to ionizing radiation in cells from children with systemic lupus erythematosus (SLE), juvenile rheumatoid arthritis (JRA), systemic sclerosis (SSc) and dermatomyositis. Peripheral blood lymphocytes from patients with SLE, JRA and SSc had significantly. DNA Damage & Repair. Genomic and mitochondrial DNA undergo constant damaging events generated by both exogenous (e.g. ultraviolet and ionizing radiation, chemotherapeutic agents, chemical combustion products) and endogenous (e.g. reactive oxygen species, nucleases) genotoxic insults. These stimuli can generate errors in the chemical structure.

render the classical DNA repair systems more readily available to correct the effects of IR. eLife digest X-rays and other forms of ionizing radiation can damage DNA and proteins inside cells. The radiation interacts with aqueous solutions to produce reactive forms of oxygen, which then cause the damage Exogenous DNA damage develops after the exposure of DNA to environmental agents, including genotoxic/cytotoxic chemicals and physical factors such as extrinsically inflicted UV and ionizing radiation, driving the frequency of DNA single (SSB) and double strand breaks (DSB)

Repair of ionizing radiation-induced DNA damage and risk

Time-lapse analysis offers new look at how cells repair DNA damage. The top image shows a cell before radiation exposure. The bottom image shows the same cell after exposure to 1 Gy of radiation. They explain that this phenomenon is in part due to the tendency of the human body to adapt to radiation and to repair the damage. This is manifested by the ability of the body to repair DNA and other molecules, so that the overall impact on the body is less severe than if the body was exposed to this dose at a higher rate, over a short period. blasts after ionizing radiation. Due to the sensitivity of this assay, repair of base damage after 3 to 6 kilorads has been measured after oxic or hypoxic radiation. With 5.5 kilorads of oxic radiation, more than 50% of the base damage was removed after 1.5 h of repair incubation in all cells What kind of DNA damage is induced by Ionizing radiation. Single strand breaks Double strand breaks Base damage Cross-linking. Used as last ditch effort to repair heavily damaged DNA. 10+ polymerases >If DNA damage is heavy, DNA polymerase will stall during replication NASA is working hard on studying DNA repair in space because astronauts traveling outside of the atmosphere have an increased risk of DNA damage due to ionizing radiation

Cockayne syndrome (CS) cells are defective in transcription-coupled repair (TCR) and sensitive to oxidizing agents, including ionizing radiation. We examined the hypothesis that TCR plays a role in ionizing radiation-induced oxidative DNA damage repair or alternatively that CS plays a role in transcription elongation after irradiation. Irradiation with doses up to 100 Gy did not inhibit RNA. 7.3: Ionizing Radiation. High energy radiation, such as X-rays, γ -rays, and β particles (or electrons) are powerful mutagens. Since they can change the number of electrons on an atom, converting a compound to an ionized form, they are referred to as ionizing radiation. They can cause a number of chemical changes in DNA, including directly. Medical staff represent the largest group of workers occupationally exposed to ionizing radiation (IR). Chronic exposure to low-dose IR may result in DNA damage and genotoxicity associated with increased risk of cancer. This review aims to identify the genotoxicity biomarkers that are the most elevated in IR-exposed vs. unexposed health workers. A systematic review of the literature was. Base-excision repair of oxidative DNA damage. 2007 Jun 21;447(7147):941-50.) So, what about those pesky cell phones? Do they emit ionizing radiation? No. Cell phones emit radiofrequency energy, a form of non-ionizing electromagnetic radiation. Non-ionizing radiation is considered safe, though it can cause som

Radiation Effects on Cells & DNA Let's Talk Scienc

Repair of DNA double-strand breaks after ionizing radiation. Maintaining the continuity and stability of each nuclear DNA molecule is fundamentally important in preventing chromosomal rearrangements that can lead to cancer through altered gene expression. The direct breaks (in the sense of arising instantaneously) produced by IR, as well as. As ionizing radiation induces oxidative damage in addition to DNA double-strand breaks, increased FEN1 expression after DNA damage may contribute to radiotherapy resistance via modulation of the oxidative stress response, a concept supported by the finding that ROS and free radicals generated by damage play a role in the response of AR to damage Radiation damage to cells can either occur directly or indirectly. [1] Most of the notable damage occurs to the cell DNA. Cells have repair mechanisms to fix this damage, but these mechanisms are not perfect and occassionally damage persists. This damage can have consequences such as cell death or development of cancer For the combined treatment of anti-p53R2 siRNA and DNA damage, cells were transfected as described above, then replated at 24 h posttransfection as single cells (60,000 cells for 2 Gy ionizing radiation; 120,000 cells for 4 Gy ionizing radiation; 30,000 cells for 0.01 or 0.05 μg/mL doxorubicin treatment) into 100 mm culture dishes

DNA DAMAGE RESPONSE AND THE FIDELITY OF DNA REPAIR Evidence of DNA damage after radiation exposure and the immedi-ate downstream manifestations of that damage was a major component of the BEIR VII report. The topic was also recently DSBs against those produced by ionizing radiation ( 15). Siegel et al • Radiation biology is the study of the action of ionizing radiation on living organisms • The action is very complex, involving physics, chemistry, and biology - Different types of ionizing radiation - Energy absorption at the atomic and molecular level leads to biological damage - Repair of damage in living organism

Absolutely, radiation damages DNA, among other things. There is a good review of all radiation damage to cells in Ionizing radiation-induced DNA injury and damage detection in patients with breast cancer. It is the DNA damage that leads to mutatio.. 5.3 INTERACTIONS OF IONIZING RADIATION WITH DNA . Chapter 2 provides an overview of the types of radiation and their ability to transfer energy when ionizing biological matrices. The interaction of radiation with all molecules (including DNA and other cellular components) may be classified as either direct or indirect interactions We used a single-cell alkaline gel electrophoresis (SCAGE) assay to study repair of primarily single-stranded DNA breaks after in vitro exposure to ionizing radiation in cells from children with systemic lupus erythematosus (SLE), juvenile rheumatoid arthritis (JRA), systemic sclerosis (SSc) and dermatomyositis. Peripheral blood lymphocytes from patients with SLE, JRA and SSc had significantly. The mechanistic mathematical model of repair proposed in this thesis is part of a bottom - up appr oach that assumes the cell is a complex system. In this approach radiation induces DNA damage, and the cellular response to radiation perturbation was modelled in terms of activating repair processes

The radiation you get from x-ray, CT, and nuclear imaging is ionizing radiation — high-energy wavelengths or particles that penetrate tissue to reveal the body's internal organs and structures. Ionizing radiation can damage DNA, and although your cells repair most of the damage, they sometimes do the job imperfectly, leaving small areas of. Double-stranded breaks (DSBs) are the most common form of DNA damage associated with ionizing radiation. After DSBs are generated, a cascade of enzymatic processes is triggered to allow for DNA repair or to induce apoptosis. This process includes the activation of p53 and the induction of cell cycle arrest. If the damage exceeds the cell's. Acquired mutations are caused from damage to DNA in somatic cells. DNA-repair genes fix mistakes of cellular mutation and repair replication errors. If these mutate, subsequent accumulations of cancer-causing mutations may occur. Ionizing radiation can affect the DNA repair process causing molecular changes in the DNA Here, we report that vigilin depletion increased cell sensitivity to cisplatin- or ionizing radiation (IR)-induced cell death and genomic instability due to defective DNA repair. Vigilin depletion delayed dephosphorylation of IR-induced γ -H2AX and elevated levels of residual 53BP1 and RIF1 foci, while reducing Rad51 and BRCA1 focus formation.

Effects of Low Dose Ionizing Radiation on DNA Damage and Repair Response in Proliferating Muscle Stem Cells: Authors: Odebunmi, Oluwaseun: Date: 2020-04-23: Abstract: There is substantial evidence on the carcinogenic properties of high doses of Ionizing Radiation (IR), however, whether such risks exist following exposure to low doses of. Clustered DNA damage is considered a signature of ionizing radiation: clustered DNA damage sites, which may be considered as a signature of ionising radiation, underlie the deleterious biological consequences of ionising radiationionising radiation creates significant levels of clustered DNA damage, including complex double-strand breaks (DSB) See: Biological Consequences of. Spectrum of DNA damage formed by electrons, protons (0.3-4 MeV), and αparticles (2-10 MeV) • V.A. Semenenko and R.D. Stewart. A fast Monte Carlo algorithm to simulate the spectrum of DNA damages formed by ionizing radiation. Radiat Res. 161(4), 451-457 (2004). • 150 classes of DNA damage (50 types of SSB, 50 types of base damage, and 5

Two studies provide further evidence of the potential health risks of occupational ionizing radiation exposure in interventional cardiologists. of a DNA damage/repair marker, γ-H2AX, and DNA. Ionizing radiation exposure induces highly lethal DNA damage, especially DNA double-strand breaks (DSBs), that is sensed by the cellular machinery and then subsequently repaired by either of two different DSB repair mechanisms: (1) non-homologous end joining, which re-ligates the broken ends of the DNA and (2) homologous recombination, that. Ionizing radiation is less harmful as it is high energy and forms free radicals whereas non-ionizing is low energy therefore much more harmful. DNA Damage, Mutation, and Repair Chapter Exam. Low dose ionizing radiation also induces DNA damage by oxidative stresses. Thus, we hypothesize that normally non-damaging doses of ionizing radiation will be detrimental to cells with zinc deficiency due a compromised ability to combat free radical production and compromised DNA repair

It should be constantly active and needs to respond rapidly. The rate of DNA repair depends on various factors such as the cell type and age of the cell. A cell with a damaged ability to repair DNA, which could have been induced by ionizing radiation, can do one of the following The biological effects of ionizing radiation are due to two effects it has on cells: interference with cell reproduction, and destruction of cell function. (32.2.13) 1 r a d = 0.01 J / k g. The SI unit for radiation dose is the gray (Gy), which is defined to be 1 G y = 1 J / k g = 100 r a d Ionizing radiation (IR) is an important therapeutic approach to kill cancer cells by inducing DNA double strand breaks (DSBs) that lead to cell apoptosis. However, normal cells are protected from IR-induced cell lethality by a DNA damage response system including DNA damage checkpoint activation and DNA damage repair Cellular functions of the NimA-related mammalian kinase Nek1 have not been demonstrated to date. Here we show that Nek1 is involved early in the DNA damage response induced by ionizing radiation (IR) and that Nek1 is important for cells to repair and recover from DNA damage. When primary or transformed cells are exposed to IR, Nek1 kinase activity is increased within 4 minutes, and Nek1. organism may be damaged or even die. All living things are constantly exposed to background radiation (see Fact Sheet #3: What are the Sources of Ionizing Radia-tion?) Most cells have the ability to repair some damage done by this level of radiation. As a result, the effects of doses similar to background levels are impossible to measure

Effects of ionizing radiation in nonirradiated cells | PNAS

Deinococcus radiodurans also has a unique ability to repair damaged DNA. It isolates the damaged segments in a controlled area and repairs it. These bacteria can also repair many small fragments from an entire chromosome. Mechanisms of ionizing-radiation resistance. Deinococcus accomplishes its resistance to radiation by having multiple copies. Ionizing radiation, such as an X-ray, causes free radicals to form. The free radicals break the covalent bonds joining DNA nucleotides together. When the cell tries to repair the DNA it makes. Reactive oxygen species may directly or indirectly affect the nuclear DNA by modifying bases incorporated within the DNA or deactivate the DNA-repair enzymes. Non-ionizing Radiation. UV-radiation is a common example of non-ionizing radiation, which can induce DNA damage because of the skin cells' high absorption capacity Targeting of Nrf2 induces DNA damage signaling and protects colonic epithelial cells from ionizing radiation Sang Bum Kim a, Raj K. Pandita , Ugur Eskiocak a, Peter Ly , Aadil Kaisani , Rakesh Kumarb, Crystal Cornelius , Woodring E. Wrighta, Tej K. Panditab,1, and Jerry W. Shaya,c,1 Departments of aCell Biology, and bRadiation Oncology, University of Texas Southwestern Medical Center, Dallas. Broken DNA migrates farther in the electric field, and the cell then resembles a comet with a brightly fluorescent head and a tail region which increases as damage increases. We have used video image analysis to define appropriate features of the comet as a measure of DNA damage, and have quantified damage and repair by ionizing radiation

The DNA-Damage Response to Ionizing Radiation in Human Lymphocytes Maddalena Mognato, Mauro Grifalconi, Sabrina Canova, Cristina Girardi and Lucia Celotti University of Padova, Department of Biology, Italy 1. Introduction The human genome is constantly subjected to DNA damage derived from endogenous and exogenous sources Read Ionizing radiation damage to DNA: Molecular aspects, Journal of Cellular Biochemistry on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips

Radiation Damage to DNA and its Repair. Radiation can penetrate the closely knitted structure of DNA and can tear out the molecules. The DNA, which is the heart of the cell and contains all the instructions for producing new cells can be adversely affected, by direct damage to the cellular components or indirectly through water molecules ionizing radiation on living organisms •The action is very complex, involving physics, chemistry, and biology -Different types of ionizing radiation -Energy absorption at the atomic and molecular level leads to biological damage -Repair of damage in living organisms •Basic principles are used in radiation therapy wit The major effect of ionizing radiation in cells is DNA damage. Since DNA consists of a pair of complementary strands, breaks of either a single strand or both strands can occur. Depending on the character of DNA damage, an appropriate repair mechanism will be activated The DNA mismatch repair (MMR) pathway detects and repairs DNA replication errors. While DNA MMR-proficiency is known to play a key role in the sensitivity to a number of DNA damaging agents, its role in the cytotoxicity of ionizing radiation (IR) is less well characterized Lecture 5: DNA Damage and Repair Identify the different sources and types of DNA damage o Types of DNA damage - depurination, deamination, pyrimidine dimers, double strand breaks, other hydrolysis, oxidation, methylation o Sources of DNA damage include radiation, mutagens, chemotherapy (alkylating agents) and spontaneous base hydrolysis. Replication errors: Proofreading by DNA pol not 100%.

The Epidermal Growth Factor Receptor: A Role in Repair ofH2AX phosphorylation within the G1 phase after UVIJERPH | Free Full-Text | Health Risk and BiologicalPPT - BIOLOGICAL EFFECTS OF IONIZING RADIATION AT MOLECUL