The objective is to elucidate the mechanisms by which environmental chemicals induce aneuploidy and to refine and validate assay systems capable of detecting aneugenic chemicals.
Studies indicate that lower eukaryotic systems such as those which make use of fungal cultures are not predictive for the activity of aneugenic chemicals in higher organisms. Thus, the project focuses upon the use of cell systems and intact rodents in the detection of and investigation of the mechanisms of action of environmental chemicals capable of inducing numerical chromosome changes which are of health significance to man. The major step to date was the publication of a volume of the journal Mutation Research (287(1)) in which the collaborators completed their comparative analysis of a variety of test systems using a standard set of test chemicals. This study revealed major limitations in the specificity and sensitivity of current methods and refocused the current work. Recent significant advances include: the identification of the aneugenic activity of chlorinated solvents and N-alcohols and the characterisation of the role of specific metabolic enzymes in their aneugenic activity;
comparative analysis of aneugenic activity in somatic and germ cells and the identification of a number of germ cell specific aneugens;
development and application of specific chromosome in situ hybridisation probes for the detection of aneuploidy in the rat, mouse and humans;
development of the in vitro micronucleus assay as a methodology for the detection of chemical aneugens;
characterisation of the potential aneugens to induce cell transformation as a model of chemical carcinogenesis;
molecular mechanisms of the induction of aneuploidy by spindle inhibitors.
Previous studies indicate that lower eukaryotic systems, such as those which make use of fungal cultures, are not predictive for the activity of aneugenic chemicals in higher organisms. Thus, the project focuses upon the use of cell systems and intact rodents in the detection and investigation of the mechanisms of action of environmental chemicals capable of inducing numerical chromosome changes with health significance to man.
The project involves the following work.
Identification of the cellular targets in the mammalian cells of significance in the interaction of aneugenic chemicals and the relative role of damage to such targets in induced aneuploidy.
Determination of the role of cellular and organ specific metabolism in the interaction of environmental chemicals with cellular targets of relevance.
The refinement of protocols for the detection of induced aneuploidy in cultured mammalian cells with particular focus upon the micronucleus and chromosome couting techniques. Emphasis is placed upon the development of molecular probes for the analysis of cell preparations.
The mechanisms of action and relative activities of aneugenic chemicals in both germ cells and somatic tissue will be analysed using intact rodents. Research is undertaken to determine the potential value of transgenic animals in the detection of induced aneuploidy in specific rodent tissues.
The range of chemicals evaluated in potential aneuploidy test systems is being expanded with the aim of classifying the particular chemical classes capable of interacting with relevant cellular targets.
The role of aneugenic chemicals in the progressive stages of tumour development is determined in the cell transformation assay.
Funding SchemeCSC - Cost-sharing contracts
3720 BA Bilthoven
2333 AL Leiden
106 91 Stockholm