A comparative study on the cyto- and genotoxicityof I-123- and I-125-UdR in-vitro

Kriehuber, Ralf

Conference Presentation (After Call)

FZJ-2017-07130

A comparative study on the cyto- and genotoxicityof I-123- and I-125-UdR in-vitro

Kriehuber, R. (Corresponding author)FZJ*

2011

7th International Symposium on Physical, Molecular, Cellular and Medical Aspects of Auger Processes, Jülich, Germany, 24 Aug 2011 - 26 Aug 2011

Please use a persistent id in citations: http://hdl.handle.net/2128/15658

Abstract: The Auger effect is not yet fully understood in respect to the deposited energy as well as to the dose rate. Therefore, we studied the Auger electron emitter (AEE) I-123 and I-125 which are characterized by a different half-life (13.2 h vs. 59.4 d) and by different average numbers of Auger electrons emitted per decay (ratio I-123/I-125 ~ 1:2). The biological response in mammalian cells labelled with various activity concentrations of 5-(123)iodine-2'-deoxyuridine (I-123-UdR) and (5-(125)iodine-2'-deoxyuridine (I-125-UdR) was thoroughly investigated to further elucidate the biological effectiveness of these particular electron emitters. SCL-II, Kidney-T1 and Jurkat cells were synchronized in G1-phase, subsequently labelled with I-123- respectively I-125-UdR and the cellular uptake and DNA incorporation of I-UdR was determined. Chromatin damage was quantified by the alkaline Comet assay, apoptosis induction 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. Cs-137 γ-rays served as reference radiation.I-125-UdR induced overall a slightly stronger response in human cell lines than I-123-UdR regarding micronucleus formation and chromatin damage per decay. Both AEE caused a pronounced long-lasting G2/M phase arrest. On average one decay (I-125-UdR) every 90 seconds per DNA/cell is sufficient to induce a permanent cell cycle arrest.Albeit of a lower dose rate, I-125-UdR is slightly more genotoxic in comparison with I-123-UdR.Funded by Bundesministerium für Umwelt, Natur und Reaktorsicherheit (BMU), Bundesamt für Strahlenschutz; Project No.: 3608S03002

Keyword(s): Biology (2nd)

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