Mechanisms involved in the induction of aneuploidy: the significance of chromosome loss

The induction of aneuploidy by physical and chemical agents using different test systems was evaluated. The effect of X-rays, caffeine, acetaldehyde, ethanol, diethylstilbestrol, propionaldehyde, and chloral hydrate was studi ed by chromosome counting in Chinese hamster embryonic diploid cells. Aneug enic ability of cadmium chloride, cadmium sulfate, potassium dichromate, ch romium chloride, nickel chloride, and nickel sulfate was assessed by means of anaphase-telophase analysis in Chinese hamster ovary cells. Chromosome c ounting in human fibroblasts (MRC-5 cell line) was employed to evaluate the effect of cacodilic acid. cadmium chloride, cadmium sulfate, and potassium dichromate. Finally, the induction of kinetochore-positive and kinetochore negative micronuclei by cadmium chloride, cadmium sulfate, potassium dichr omate, chromium chloride. and nickel chloride was studied using CREST antib odies. When the effect of different agents was determined by chromosome cou nting, an increase of hypoploid but not of hyperploid cells was observed. A naphase-telophase analysis showed that metal salts increased the frequency of lagging chromosomes. This finding has been confirmed by the increment of kinetochore-positive micronuclei using CREST antibodies. Therefore, chromo some loss could be considered as the main cause of induced aneuploidy.