New technologies for sound in vitro toxicology

Description

The in vitro micronucleus test is a key tool for the detection of aneugenic, i.e. spindle-apparatus mediated genotoxins which cannot be detected by bacterial systems such as Ames or umu chromotest. We have developed a new testing approach based on brain derived, strictly epithelial growing fish stem cells. These cells exhibit embryonic features as arylhydrocarbon receptor expression, the related inducibility of metabolic enzymes and the expression of the epithelial mesenchymal transition signalling pathway. Our H2B-GFP fusion protein based variants of these fish cell lines enable the detection of DNA damage using high throughput automated kinetic live imaging applied to 96 well-plate format. In addition to micro- and small nuclei, the technology can detect lost chromosomes, nucleoplasmic bridges, nuclear buds and karyorrhexis features in situ. GFP labelling of nuclear structures also allows allocation of the cell cycle status of any individual cell. The causes of reduced cell growth in terms of cytotoxicity, slowed proliferation and inhibition of cell division are visible. Impacts on monolayer morphology during a 72-h cultivation period can be recorded. The technology enables a highly efficient performance of valid micronucleus tests according to OECD 487. Known aneugens as well as clastogens are reliably recognised. Procarcinogens (cyclophosphamide, aflatoxin, 3,4 dichloroaniline), that act in standardised procedures exclusively after the introduction of (mostly animal derived) metabolic enzymes (S 9 mix technology), proved to be genotoxic in the test variant without S9 mix. Our new technology therefore has great potential to increase the efficiency of the micronucleus test at significantly lower cost, while avoiding the need for animal treatments to produce enzymes for the metabolic activation of the test compounds.

Period	04 Jun 2025
Event title	53rd congress of the EUROPEAN ENVIRONMENTAL MUTAGENESIS & GENOMICS SOCIETY: “Safeguarding Genomic Integrity: Bridging Science and Public Health in Environmental Mutagenesis“
Event type	Conference
Location	Bratislava, SlovakiaShow on map
Degree of Recognition	International