Induction by asbestos fibers of anaphase abnormalities: mechanism for aneuploidy induction and possibly carcinogenesis.

Syrian hamster embryo cells were treated with crocidolite asbestos at a dose (1 microgram/cm2) which was shown in previous studies to induce cell transformation and aneuploidy in these cells. Treatment of cells with asbestos induced a greater than 20-fold increase in the incidence of cells in anaphase with abnormalities, including lagging chromosomes, bridges, and sticky chromosomes. Asbestos fibers were observed in mitotic cells and appeared, in some cases, to be interacting directly with the chromosomes. From these studies, we propose that the physical interaction of the asbestos fibers with the chromosomes or structural proteins of the spindle apparatus causes missegregation of chromosomes during mitosis resulting in aneuploidy. These findings provide a mechanism, at the chromosomal level, by which asbestos and other mineral fibers might induce cell transformation and cancer.