Genomic Adaption and Mutational Patterns in a HaCaT Subline Resistant to Alkylating Agents and Ionizing Radiation

International Journal of Molecular Sciences

BenjaminValentin Becker¹  Annette Schmidt²  Horst Thiermann²  Simone Rothmiller²  Jessica Müller³  HannsLeonhard Kaatsch³  Reinhard Ullmann³  Matthias Port³  Gerrit Schrock³  Harry Scherthan³  Richard Obermair³  Julia Jakobi³ 

[1]Bundeswehr Central Hospital, Department of Radiology and Neuroradiology, Rübenacherstrasse 170, D-56072 Koblenz, Germany

[2]Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, D-80937 Munich, Germany

[3]Bundeswehr Institute of Radiobiology Affiliated to the University of Ulm, Neuherbergstr. 11, D-80937 Munich, Germany

关键词: chronic exposure;    DNA alkylation;    genome rearrangements;    HaCaT;    irradiation;    mutational signatures;   

DOI  :  10.3390/ijms22031146

来源: DOAJ

【 摘 要 】

Sulfur mustard (SM) is a chemical warfare agent that can damage DNA via alkylation and oxidative stress. Because of its genotoxicity, SM is cancerogenic and the progenitor of many chemotherapeutics. Previously, we developed an SM-resistant cell line via chronic exposure of the popular keratinocyte cell line HaCaT to increasing doses of SM over a period of 40 months. In this study, we compared the genomic landscape of the SM-resistant cell line HaCaT/SM to its sensitive parental line HaCaT in order to gain insights into genetic changes associated with continuous alkylation and oxidative stress. We established chromosome numbers by cytogenetics, analyzed DNA copy number changes by means of array Comparative Genomic Hybridization (array CGH), employed the genome-wide chromosome conformation capture technique Hi-C to detect chromosomal translocations, and derived mutational signatures by whole-genome sequencing. We observed that chronic SM exposure eliminated the initially prevailing hypotetraploid cell population in favor of a hyperdiploid one, which contrasts with previous observations that link polyploidization to increased tolerance and adaptability toward genotoxic stress. Furthermore, we observed an accumulation of chromosomal translocations, frequently flanked by DNA copy number changes, which indicates a high rate of DNA double-strand breaks and their misrepair. HaCaT/SM-specific single-nucleotide variants showed enrichment of C > A and T > A transversions and a lower rate of deaminated cytosines in the CpG dinucleotide context. Given the frequent use of HaCaT in toxicology, this study provides a valuable data source with respect to the original genotype of HaCaT and the mutational signatures associated with chronic alkylation and oxidative stress.

【 授权许可】

Unknown