TY  - JOUR
AU  - Unverricht-Yeboah, Marcus
AU  - Holtmann, Kathrin
AU  - Kriehuber, Ralf
TI  - Comet Assay analysis of DNA strand breaks after exposure to the DNA-incorporated Auger Electron Emitter Iodine-125
JO  - International journal of radiation biology
VL  - 99
IS  - 1
SN  - 0020-7616
CY  - Abingdon
PB  - Informa Healthcare
M1  - FZJ-2023-03098
SP  - 64 - 69
PY  - 2023
AB  - Purpose: Ionizing radiation causes various types of DNA damage e.g. single strand breaks (SSB) and double strand breaks (DSB), whereby the SSB/DSB ratio is shifted toward the DSB with increasing LET. For the DNA-incorporated Auger electron emitter Iodine-125 a SSB/DSB ratio of 5.4:1 is calculated based on computer simulations. In the presented work the SSB/DSB ratio of DNA-incorporated Iodine-125 was experimentally determined and compared to external homogenous γ-irradiation.Materials and methods: Iodine-125-iododeoxyuridine (I-125-UdR) was incorporated into the DNA of SCL-II cells and cells were subsequently frozen for decay accumulation. Accordingly, external γ-irradiation (Cs-137) experiments were performed in frozen cells. After exposure the neutral or alkaline Comet Assay was performed to quantify DSB or DSB and SSB, respectively. Automated quantification of the comets was performed using the Olive Tail Moment (Metafer CometScan; MetaSystems). Calculation of absorbed dose for Auger electrons on cellular level is extremely biased due to the exclusive DNA localization of I-125-UdR. To avoid dose calculation the γ-H2AX assay was used in order to allow the comparison of the Comet Assay data between both investigated radiation qualities.Results: For low-LET γ-radiation, a SSB/DSB ratio of 10:1 was determined. In contrast, a lower SSB/DSB ratio of 6:1 was induced by DNA-incorporated Iodine-125 which compares very well to the calculated values of Pomplun and co-authors.Conclusion: DNA-incorporated Iodine-125 induces a high-LET type DNA damage pattern in respect to SSB/DSB ratio.Keywords: Auger Electron Emitter; Comet Assay; Iodine-125; high-LET type DNA damage
LB  - PUB:(DE-HGF)16
C6  - 33211630
UR  - <Go to ISI:>//WOS:000596176800001
DO  - DOI:10.1080/09553002.2020.1851059
UR  - https://juser.fz-juelich.de/record/1010515
ER  -