Cyto- and genotoxicity of 123I- and 125I-UdR in vitro: Apoptosis induction, micronucleus formation and chromatin damage in three human cell lines

Kriehuber, Ralf

Conference Presentation (Invited)

FZJ-2017-07163

Cyto- and genotoxicity of 123I- and 125I-UdR in vitro: Apoptosis induction, micronucleus formation and chromatin damage in three human cell lines

Kriehuber, R. (Corresponding author)FZJ*

2010

56th Annual Meeting of the Radiation Research Society, RADRES, Maui Hawaii, USA, 25 Sep 2010 - 29 Sep 2010

Please use a persistent id in citations: http://hdl.handle.net/2128/15681

Abstract: The Auger electron emitters (AEE) 123I and 125I are characterized by different half-lifes (13.2 h vs. 59.4 d) and by different average numbers of Auger electrons emitted per decay (8 vs. 15). The biological response in synchronized mammalian cells labelled with various activity concentrations of 123I- and 125I-UdR were investigated and compared in respect to accumulated decays and dose rate to further elucidate the biological effectiveness of Auger electrons. SCL-II, Kidney-T1 and Jurkat cells were synchronized in G1-phase, subsequently labelled with 123I- respectively 125I-UdR and the cellular up-take and DNA-incorporation of I-UdR were determined. Chromatin damage was quantified by the alkaline Comet-assay, apoptosis induction was assessed by the Annexin V/PI assay employing flow cytometry and micronucleus formation was quantified using the Cytochalasin-B–micronucleus assay at various times post-labelling. 137Cs gamma rays served as reference radiation.125I-UdR induced overall a slightly stronger response in human cell lines than 123I-UdR regarding micronucleus formation and chromatin damage. Apoptosis induction was much more profound in 125I-UdR-labelled cells immediately after labelling when compared to 123I-UdR. Both AEE induced a pronounced long-lasting G2/M phase arrest.Albeit of a lower dose rate, 125I-UdR is 1.2 to 1.5 times more genotoxic in comparison with 123I-UdR. On average one decay (125I-UdR) every 120 seconds per DNA/cell is sufficient to induce a permanent cell cycle arrest.

Keyword(s): Biology (2nd)

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