• Title/Summary/Keyword: DNA Damage

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THE EFFECT OF GENETIC VARIATION IN THE DNA BASE REPAIR GENES ON THE RISK OF HEAD AND NECK CANCER (DNA 염기손상 치유유전자의 변이와 두경부암 발생 위험성)

  • Oh, Jung-Hwan;Yoon, Byung-Wook;Choi, Byung-Jun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.34 no.5
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    • pp.509-517
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    • 2008
  • DNA damage accumulates in cells as a result of exposure to exogenous agents such as benzopyrene, cigarette smoke, ultraviolet light, X-ray, and endogenous chemicals including reactive oxygen species produced from normal metabolic byproducts. DNA damage can also occur during aberrant DNA processing reactions such as DNA replication, recombination, and repair. The major of DNA damage affects the primary structure of the double helix; that is, the bases are chemically modified. These modification can disrupt the molecules'regular helical structure by introducing non-native chemical bonds or bulky adducts that do not fit in the standard double helix. DNA repair genes and proteins scan the global genome to detect and remove DNA damage and damage to single nucleotides. Direct reversal of DNA damage, base excision repair, double strand break. DNA repair are known relevant DNA repair mechanisms. Four different mechanisms are distinguished within excision repair: direct reversal, base excision repair, nucleotide excision repair, and mismatch repair. Genetic variation in DNA repair genes can modulate DNA repair capacity and alter cancer risk. The instability of a cell to properly regulate its proliferation in the presence of DNA damage increase risk of gene mutation and carcinogenesis. This article aimed to review mechanism of excision repair and to understand the relationship between genetic variation of excision repair genes and head and neck cancer.

Protective Effect of Yellow-Green Vegetable Juices on DNA Damage in Chinese Hamster Lung Cell Using Comet Assay (Comet Assay를 이용한 케일, 명일엽, 당근, 돌미나리 녹즙의 Chinese Hamster Lung 세포 DNA 손상 보호 효과)

  • 전은재;김정신;박유경;김태석;강명희
    • Journal of Nutrition and Health
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    • v.36 no.1
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    • pp.24-31
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    • 2003
  • The present study was attempted to investigate the antioxidant capacity of popular yellow-green vegetable juices (kale, Angelica keishei, carrot, small water dropwort) and to investigate the effect of vegetable juices on protecting oxidative damage to DNA in cultured Chinese hamster lung (CHL) cells. Antioxidant capacity was analyzed by TRAP assay (Total radical-trapping antioxidant potential). Cellular DNA dmamage was measured by SCGE (single-cell gel electrophoresis, also known as comet assay. Cells incubated in medium with PBS (negative control) or with various concentration of the freeze dried green juices (25, 50, 100, 250 $\mu\textrm{g}$/$m\ell$) resuspended in PBS were treated with $H_2O_2$ (200 ${\mu}{\textrm}{m}$) as an oxidative stimulus for 5 min at 4$^{\circ}C$. The physiological function of each vegetable juice on oxidative DNA damage was analyzed and expressed as tail moment (tail length X percentage migrated DNA in tail) . Kale juice had the highest TRAP value suggesting that kale has the highest antioxidant capacity followed by Angelica keishei, small water dropwort and carrot. Cells treated with $H_2O_2$ had extensive DNA damage compared with cells treated with PBS or pre-treated with vegetable juice extracts. All green juices inhibited $H_2O_2$-induced DNA damage with kale being the most effective juice among the tested juices. These results indicate that green juice supplementation to CHL cells followed by oxidative stimulus inhibited damage to cellular DNA, supporting a protective effect against oxidative damage induced by reactive oxygen species. (Korean J Nutrition 36(1) : 24-31, 2003)

Effect of Several Drugs of DNA, RNA and Protein Damage induced by Dimethylnitrosamine in Mouse Tissues (수종약물이 Dimethylnitrosamine에 의한 DNA, RNA 및 단백질 손상도에 미치는 영향)

  • Kim, Jea-Hyun;Park, Jung-Sik;Hong, Sung-Ryul;Kweon, O-Cheul;Park, Chang-Won;Rhee, Dong-Kwon
    • YAKHAK HOEJI
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    • v.35 no.6
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    • pp.522-529
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    • 1991
  • The purpose of this research is to evaluate effects of chloramphenicol, phenobarbital and progesterone on damage of DNA, RNA and protein which was induced by dimethylnitrosamine. $N,N-Di[^{14}C]$ methyl-nitrosamine (DMN) was used as a damaging agent and levels of DNA, RNA and protein damage in liver, brain and pancreas were compared with a control group. Pretreatment of mice with chloramphenicol increased protein damage in pancreas two times more than the control level. Liver RNA damage was increased up to 5.8 times and brain DNA damage up to 6.95 times by treatment of phenobarbital but brain RNA damage was decreased significantly down to 21% of the control group. The damage of liver RNA was significantly decreased by treatment of progesterone, although liver protein damage, pancreas RNA damage and pancreas protein damage were increased.

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Suppressive Effect of Galangin on the Formation of 8-OH2'dG and DNA Single Strand Breaks by Hydrogen Peroxide ($H_2O_2$ 유도 8-OH2'dG 생성 및 DNA Single Strand Break에 미치는 Galangin의 억제효과)

  • Kim, Soo-Hee;Heo, Moon-Young
    • YAKHAK HOEJI
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    • v.54 no.1
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    • pp.32-38
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    • 2010
  • The aim of this study was to evaluate the effect of galangin towards hydrogen peroxide-induced DNA damage. The calf thymus DNA and Chinese Hamster Lung (CHL) cells were used to measure 8-hydroxy-2'-deoxyguanosine(8-OH2'dG) as an indicator of DNA oxidative damage using high performance liquid chromatography with electrochemical detection. Hydrogen peroxide in the presence of Fe(II) ion induced the formation of 8-OH2'dG in both calf thymus DNA and CHL cells. The DNA damage effects were enhanced by increasing the concentration of Fe(II) ion and inhibited by galangin. In the single cell gel electrophoresis (Comet assay), galangin and dl-a-tocopherol showed an inhibitory effect in CHL on hydrogen peroxide induced DNA single strand breaks. Galangin showed more potent activity than dl-$\alpha$-tocopherol under our experimental conditions. These results indicate that galangin can modify the action mechanisms of the oxidative DNA damage and may act as chemopreventive agents against oxidative stress.

XPS STUDY ON DNA DAMAGE BY LOW-ENERGY ELECTRON IRRADIATION

  • Noh, Hyung-Ah;Cho, Hyuck
    • Journal of Radiation Protection and Research
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    • v.36 no.4
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    • pp.190-194
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    • 2011
  • After the first report that electrons with sub-ionization energy of DNA could cause single strand breaks or double strand breaks to DNA, there have been various studies to investigate the mechanisms of DNA damage by low-energy electrons. In this paper, we examined the possibility of using X-ray photoelectron spectroscopy (XPS) to analyze the dissociation patterns of the molecular bonds by electron irradiation on DNA thin films and tried to establish the method as a general tool for studying the radiation damage of biomolecules by low energ yelectrons. For the experiment, pBR322 plasmid DNA solution was formed into the films on tantalum plates by lyophilization and was irradiated by 5-eV electrons. Un-irradiated and irradiated DNA films were compared and analyzed using the XPS technique.

Cellular DNA Repair of Oxidative Deoxyribose Damage by Mammalian Long-Patch Base Excision Repair

  • Sung Jung-Suk;Son Mi-Young
    • Biomedical Science Letters
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    • v.11 no.2
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    • pp.103-108
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    • 2005
  • 2-Deoxyribonolactone (dL) arises as a major DNA damage induced by a variety of agents, involving free radical attack and oxidation of C1'-deoxyribose in DNA. We investigated whether dL lesions can be repaired in mammalian cells and the mechanisms underlying the role of DNA polymerase $\beta$ in processing of dL lesions. Pol $\beta$ appeared to be trapped by dL residues, resulting in stable DNA-protein cross-links. However, repair DNA synthesis at site-specific dL sites occurred effectively in cell-free extracts, but predominantly accompanied by long-patch base excision repair (BER) pathway. Reconstitution of long-patch BER demonstrated that FEN1 was capable of removing the displaced flap DNA containing a 5'-dL residue. Cellular repair of dL lesions was largely dependent on the DNA polymerase activity of Pol $\beta$. Our observations reveal repair mechanisms of dL and define how mammalian cells prevent cytotoxic effects of oxidative DNA lesions that may threaten the genetic integrity of DNA.

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Detection of Irradiated Astragalus membranaeus Bunge and Havenia duzcis Thumb Using DNA Comet Assay

  • Yi, Jin-Hee ;Song, Kyung-Bin
    • Preventive Nutrition and Food Science
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    • v.7 no.3
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    • pp.323-326
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    • 2002
  • Ionizing radiation can be used to sanitize herbs contaminated by various microorganisms. However, health concerns related to irradiation damage to complex molecules in plants necessitate that methods be developed to monitor such damage. To elucidate DNA damage of herbs caused by irradiation, the DNA comet assay was used for Astragalus membranaceus Bunge and Havenia dulcis Thumb, irradiated at 1, 5, 7, and 10 kGy. With increasing irradiation doses, the tails of comets became longer with average tail length increasing from 17 (non-irradiated) to 124 (10 kGy) $\mu$m in Astragalus membranaceus Bunge. Above 7 kGy, some of the tails were separated from the heads of comets. Distribution patterns of the tail length of In comets selected randomly in the irradiated herbs were analyzed to quantify the DNA damage. These results clearly suggest that the DNA comet assay is an effective and inexpensive tool for the detection of irradiation damage to DNA in herbs.

Suppressive Effect of Acanthopanax sessiliflorus Extract on the DNA and Cell Damage by Dieldrin (Dieldrin에 의한 DNA와 세포 손상에 대한 오가피 추출물의 억제효과)

  • Ryu, A-Reum;Kim, Ji-Hae;Lee, Mi-Young
    • Korean Journal of Medicinal Crop Science
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    • v.20 no.4
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    • pp.245-250
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    • 2012
  • Dieldrin, one of the organochlorine pesticides (OCPs), induced the damages in neuroblastoma cells and DNA damages in lymphocytes. The ethanol extracts of A. sessiliflorus leaves were examined for the suppressive effects on the dieldrin-induced cell damages. Moreover, the extract was used to test whether it might inhibit the oxidative DNA damage of lymphocytes using Comet assay. The cell and DNA damage by dieldrin were suppressed in vitro upon treating A. sessiliflorus extract. This result suggests that A. sessiliflorus extract might be useful to reduce dieldrin toxicity.

Genetic Screen for Genes Involved in Chk2 Signaling in Drosophila

  • Park, Suk-Young;Song, Young-Han
    • Molecules and Cells
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    • v.26 no.4
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    • pp.350-355
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    • 2008
  • Chk2 is a well characterized protein kinase with key roles in the DNA damage response. Chk2 is activated by phosphorylation following DNA damage, and relays that signal to various substrate proteins to induce cell cycle arrest, DNA repair, and apoptosis. In order to identify novel components of the Chk2 signaling pathway in Drosophila, we screened 2,240 EP misexpression lines for dominant modifiers of an adult rough eye phenotype caused by Chk2 overexpression in postmitotic cells of the eye imaginal disc. The rough eye phenotype was suppressed by mutation of the ATM kinase, a well-described activator of Chk2. Twenty-five EP modifiers were identified (three enhancers and 22 suppressors), none of which correspond to previously known components of Chk2 signaling. Three EPs caused defects in G2 arrest after irradiation with incomplete penetrance when homozygous, and are likely directly involved in the response to DNA damage. Possible roles for these modifiers in the DNA damage response and Chk2 signaling are discussed.

Antioxidant activity and protective effects on oxidative DNA damage of Smilax china root (토복령의 항산화 및 산화적 DNA 손상억제 활성)

  • Jang, Tae-Won;Oh, Chang-Gun;Park, Jae-Ho
    • Journal of Applied Biological Chemistry
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    • v.61 no.2
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    • pp.109-117
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    • 2018
  • Recently, cancer incidence in modern society is increasing sharply. DNA damage is caused by intrinsic or extrinsic factors in the human body, cells protect themselves by defense mechanism against DNA damage. Also, Aberrant DNA and deficient DNA repair are closely associated with various diseases, including aging and cancer. Researchers are interested in search for proper materials to inhibition for DNA damage. As knew the side effects of synthetic antioxidant, some researches have been conducted about cancer prevention materials derived from nature. Root of Smilax china, in Liliaceae, is used detoxification and tumor treatments traditionally. However, studies on the inhibitory effect of DNA damage haven't progressed. In this study, antioxidant activity and protective effects on oxidative DNA damage of S. china root were confirmed, relationship between those activities and contents of phenolic compounds in plants were established. S. china root effectively removed 1,1-diphenyl-2-picryl-hydrazyl radicals and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid radicals. The quantification and identification of phenolic compounds were confirmed by high performance liquid chromatography analysis, its antioxidant activity was associated with some phenolic compounds. In addition, protective effects against hydroxyl radicals and ferrous ion-induced oxidative DNA damage were confirmed in plasmid DNA. In the cellular levels, S. china root suppressed the expression of ${\gamma}$-H2AX and p53 protein in NIH 3T3. Besides, S. china root suppressed H2AX and p53 mRNA levels. In conclusion, S. china root had the effect on DNA protection and antioxidant.