Long-term fate of etoposide-induced micronuclei and micronucleated cells in Hela-H2B-GFP cells
- PDF / 1,468,673 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 2 Downloads / 162 Views
GENOTOXICITY AND CARCINOGENICITY
Long‑term fate of etoposide‑induced micronuclei and micronucleated cells in Hela‑H2B‑GFP cells Hauke Reimann1 · Helga Stopper1 · Henning Hintzsche1,2 Received: 20 April 2020 / Accepted: 9 July 2020 © The Author(s) 2020
Abstract Micronuclei are small nuclear cellular structures containing whole chromosomes or chromosomal fragments. While there is a lot of information available about the origin and formation of micronuclei, less is known about the fate of micronuclei and micronucleated cells. Possible fates include extrusion, degradation, reincorporation and persistence. Live cell imaging was performed to quantitatively analyse the fates of micronuclei and micronucleated cells occurring in vitro. Imaging was conducted for up to 96 h in HeLa-H2B-GFP cells treated with 0.5, 1 and 2 µg/ml etoposide. While a minority of micronuclei was reincorporated into the main nucleus during mitosis, the majority of micronuclei persisted without any alterations. Degradation and extrusion were observed rarely or never. The presence of micronuclei affected the proliferation of the daughter cells and also had an influence on cell death rates. Mitotic errors were found to be clearly increased in micronucleus-containing cells. The results show that micronuclei and micronucleated cells can, although delayed in cell cycle, sustain for multiple divisions. Keywords Micronuclei · Cell fate · Etoposide · Live imaging · DNA damage
Introduction Micronuclei are small nuclear cellular structures usually formed during mitosis. They can contain whole chromosomes or chromosomal fragments, which can be distinguished by the presence of kinetochores in the micronuclei (Norppa and Falck 2003). Micronuclei are used as end point for chromosomal mutation in the micronucleus test, which is routinely conducted in genotoxicity testing (OECD 2016). Furthermore, the frequency of micronuclei in peripheral lymphocytes is considered predictive for the cancer risk in humans (Bonassi et al. 2007). Typical causes for the formation of micronuclei are, amongst others, spindle attachment Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00204-020-02840-0) contains supplementary material, which is available to authorized users. * Henning Hintzsche [email protected]‑wuerzburg.de 1
Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Straße 9, 97078 Würzburg, Germany
Bavarian Health and Food Safety Authority, Eggenreuther Weg 43, 91058 Erlangen, Germany
2
defects or DNA double-strand breaks (Kisurina-Evgenieva et al. 2016). While there is a lot of information available about the origin and formation of micronuclei, less is known about the fate of the micronuclei and micronucleated cells. Only a limited amount of systematic studies have addressed the fate of micronuclei, but some possibilities have been described during the last years, e.g. extrusion, degradation, reincorporation and persistence of micronuclei (Hintzsche et al. 2017; Stopper and Hintzsche
Data Loading...
