Investigation of Auger Electron Emitting Radionuclides Effects in Therapy Using the Geant4-DNA Toolkit: A Simulation Study

Purpose: The biological effects of ionizing radiation at the cellular and subcellular scales are studied by the number of breaks in the DNA molecule that provides a quantitative description of the stochastic aspects of energy deposition at cellular scales. The Geant4 code represents a suitable theoretical toolkit in microdosimetry and nanodosimetry. In this study, radiation effects due to Auger electrons emitting radionuclides such as 195mPt 113mIn, 125I and 201Tl are investigated using the Geant4-DNA. Materials and Methods: The Geant4-DNA is the first Open-access software for the simulation of ionizing radiation and biological damage at the DNA scale. Low-energy electrons, especially Auger electron from Auger electron emitting radionuclides during the slowing-down process, deposit their energy within a nanometer volume. Results: The average number of Single-Strand Breaks (SSB) and Double-Strand Breaks (DSB) of DNA as a function of energy and distance from the center of the DNA axis are shown. Conclusion: The highest DSBs yield has occurred at energies less than 1 keV, and induces a higher DSBs yield.

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DNA DAMAGE AND REPAIR IN EUKARYOTIC CELLS

Genetics ◽

10.1093/genetics/78.1.139 ◽

1974 ◽

Vol 78 (1) ◽

pp. 139-148

Author(s):

R B Painter

Keyword(s):

Ionizing Radiation ◽

Excision Repair ◽

Double Strand Breaks ◽

Single Strand ◽

Premature Aging ◽

Cross Linking ◽

Base Damage ◽

Strand Breaks ◽

Single Strand Breaks ◽

Post Replication Repair

ABSTRACT Damage in DNA after irradiation can be classified into five kinds: base damage, single-strand breaks, double-strand breaks, DNA-DNA cross-linking, and DNA-protein cross-linking. Of these, repair of base damage is the best understood. In eukaryotes, at least three repair systems are known that can deal with base damage: photoreactivation, excision repair, and post-replication repair. Photoreactivation is specific for UV-induced damage and occurs widely throughout the biosphere, although it seems to be absent from placental mammals. Excision repair is present in prokaryotes and in animals but does not seem to be present in plants. Post-replication repair is poorly understood. Recent reports indicate that growing points in mammalian DNA simply skip past UV-induced lesions, leaving gaps in newly made DNA that are subsequently filled in by de novo synthesis. Evidence that this concept is oversimplified or incorrect is presented.—Single-strand breaks are induced by ionizing radiation but most cells can rapidly repair most or all of them, even after supralethal doses. The chemistry of the fragments formed when breaks are induced by ionizing radiation is complex and poorly understood. Therefore, the intermediate steps in the repair of single-strand breaks are unknown. Double-strand breaks and the two kinds of cross-linking have been studied very little and almost nothing is known about their mechanisms for repair.—The role of mammalian DNA repair in mutations is not known. Although there is evidence that defective repair can lead to cancer and/or premature aging in humans, the relationship between the molecular defects and the diseased state remains obscure.

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Detection of Single-Strand Breaks and Base Damage in DNA of Human White Blood Cells as a Tool for Biological Dosimetry of Exposure to Ionizing Radiation

Military Medicine ◽

10.1093/milmed/167.suppl_1.5 ◽

2002 ◽

Vol 167 (suppl_1) ◽

pp. 5-7

Author(s):

Govert P. van der Schans ◽

Arie J. Timmerman ◽

Pieter L.B. Bruijnzeel

Keyword(s):

Ionizing Radiation ◽

Blood Cells ◽

White Blood Cells ◽

Single Strand ◽

Base Damage ◽

Strand Breaks ◽

Biological Dosimetry ◽

Single Strand Breaks ◽

Human White Blood Cells

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TDP1 facilitates repair of ionizing radiation-induced DNA single-strand breaks

DNA Repair ◽

10.1016/j.dnarep.2007.04.015 ◽

2007 ◽

Vol 6 (10) ◽

pp. 1485-1495 ◽

Cited By ~ 53

Author(s):

Sherif F. El-Khamisy ◽

Edgar Hartsuiker ◽

Keith W. Caldecott

Keyword(s):

Ionizing Radiation ◽

Single Strand ◽

Strand Breaks ◽

Single Strand Breaks ◽

Radiation Induced

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Role of DNA Damage and Repair in Detrimental Effects of Ionizing Radiation

Radiation ◽

10.3390/radiation1010001 ◽

2020 ◽

Vol 1 (1) ◽

pp. 1-4

Author(s):

Alexandros G. Georgakilas

Keyword(s):

Dna Damage ◽

Ionizing Radiation ◽

Biological Effects ◽

Full Range ◽

High Quality Research ◽

Dna Damage And Repair ◽

Biological Damage ◽

Biological Responses ◽

Technical Advances ◽

Living Organisms

Ionizing radiation (IR) is considered a traditional mutagen and genotoxic agent. Exposure to IR affects in all cases biological systems and living organisms from plants to humans mostly in a pernicious way. At low (<0.1 Gy) and low-to-medium doses (0.1–1 Gy), one can find in the literature a variety of findings indicating sometimes a positive-like anti-inflammatory effect or detrimental-like toxicity. In this Special Issue and in general in the current research, we would like to acquire works and more knowledge 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. Emphasis should be given to advances offering mechanistic insights into the ability of radiations with different qualities to severely impact cells or tissues. High-quality research or review studies on different species projected to humans are welcome. Technical advances reporting on the methodologies to accurately measure DNA or other types of biological damage must be highly considered for the near future in our research community, as well. Last but not least, clinical trials or protocols with improvements to radiation therapy and radiation protection are also included in our vision for the advancement of research regarding biological effects of IR.

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