The Role of Long-Term DNA Replication Stress Induced by Hydroxyurea in Meristematic Root Cells of Allium cepa
- 1Department of Cytophysiology, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Łódź, Poland
- 2Department of Pathomorphology, Synevo, 90-236 Łódź, Poland
Abstract
Replication stress (RS) is a process characterized by impaired DNA replication, resulting in the slowing down or arrest of replication forks (RFs) and in the activation of the DNA damage response. The aim of this study was to investigate the effects of 24, 48, 72 and 96 h exposures of Allium cepa root meristematic cells to hydroxyurea (HU) at concentrations of 1, 2, 3 and 4 mM on cell nucleus morphology, DNA replication dynamics, mitotic activity and the production of reactive oxygen species (ROS), including hydrogen peroxide (H2O2) and superoxide anion (O2∙−). Furthermore, to assess epigenetic changes associated with DNA damage, the level of acetylation of lysine 56 of histone H3 (H3K56Ac) was analyzed. It was demonstrated that incubation of roots in 1 mM HU leads to the appearance of so-called interphase–mitotic (I-M) cells. Furthermore, as the HU concentration increased, inhibition of mitotic activity, a slowing down or partial inhibition of DNA replication, and the accumulation of reactive oxygen species (ROS) were observed. Furthermore, after 24 and 48 h of incubation with 1, 2 and 3 mM HU, a similar increase in the mean fluorescence intensity of H3K56Ac was observed, with the highest intensity recorded following treatment with 4 mM HU. Prolongation of the incubation time with the inhibitor to 72 and 96 h led to a further increase in fluorescence in the cell nuclei. The obtained results indicate that the increase in H3K56Ac levels may be associated with the accumulation of DNA damage under conditions of prolonged exposure to HU.
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BibTeX
@article{zabka2026role,
title = {{The Role of Long-Term DNA Replication Stress Induced by Hydroxyurea in Meristematic Root Cells of Allium cepa}},
author = {Aneta Żabka and Natalia Gocek-Szczurtek and Mateusz Wróblewski and Klaudia Cieślak and Justyna Teresa Polit},
journal = {International Journal of Molecular Sciences},
year = {2026},
month = nov,
doi = {10.3390/ijms27219995},
url = {https://www.mdpi.com/1422-0067/27/21/9995},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - The Role of Long-Term DNA Replication Stress Induced by Hydroxyurea in Meristematic Root Cells of Allium cepa
AU - Aneta Żabka
AU - Natalia Gocek-Szczurtek
AU - Mateusz Wróblewski
AU - Klaudia Cieślak
AU - Justyna Teresa Polit
PY - 2026
DA - 2026/11/07
JO - International Journal of Molecular Sciences
DO - 10.3390/ijms27219995
UR - https://www.mdpi.com/1422-0067/27/21/9995
AB - Replication stress (RS) is a process characterized by impaired DNA replication, resulting in the slowing down or arrest of replication forks (RFs) and in the activation of the DNA damage response. The aim of this study was to investigate the effects of 24, 48, 72 and 96 h exposures of Allium cepa root meristematic cells to hydroxyurea (HU) at concentrations of 1, 2, 3 and 4 mM on cell nucleus morphology, DNA replication dynamics, mitotic activity and the production of reactive oxygen species (ROS), including hydrogen peroxide (H2O2) and superoxide anion (O2∙−). Furthermore, to assess epigenetic changes associated with DNA damage, the level of acetylation of lysine 56 of histone H3 (H3K56Ac) was analyzed. It was demonstrated that incubation of roots in 1 mM HU leads to the appearance of so-called interphase–mitotic (I-M) cells. Furthermore, as the HU concentration increased, inhibition of mitotic activity, a slowing down or partial inhibition of DNA replication, and the accumulation of reactive oxygen species (ROS) were observed. Furthermore, after 24 and 48 h of incubation with 1, 2 and 3 mM HU, a similar increase in the mean fluorescence intensity of H3K56Ac was observed, with the highest intensity recorded following treatment with 4 mM HU. Prolongation of the incubation time with the inhibitor to 72 and 96 h led to a further increase in fluorescence in the cell nuclei. The obtained results indicate that the increase in H3K56Ac levels may be associated with the accumulation of DNA damage under conditions of prolonged exposure to HU.
SN - 1422-0067
ER -