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

Our plain-English summary of Induction by asbestos fibers of anaphase abnormalities: mechanism for aneuploidy induction and possibly carcinogenesis, by T.W. Hesterberg, J.C. Barrett (Carcinogenesis, 1985).

The study

• Authors: T.W. Hesterberg, J.C. Barrett
• Journal: Carcinogenesis
• Published: 1985;6(3):473-5
• Cited by: 90 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

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.

In plain English

This short laboratory report studied hamster cells grown in culture, not people or live animals. The authors treated Syrian hamster embryo cells with crocidolite asbestos at 1 microgram per square centimeter, a dose their earlier studies had linked to cell transformation and abnormal chromosome numbers (aneuploidy) in these cells. They then examined cells in anaphase, the stage of cell division when chromosomes separate, looking for lagging, bridging or sticky chromosomes. In untreated cultures, 1 of 120 anaphases (0.8%) was abnormal, with a single lagging chromosome. In asbestos-treated cultures, 22 of 120 anaphases (18%) had displaced chromosomes, a more than 20-fold increase. Many of these had more than one. Fibers sometimes appeared to touch chromosomes, but the authors could not tell whether this happened in living cells or came from slide preparation. The authors proposed that physical contact between fibers and chromosomes or the cell's division machinery makes chromosomes separate wrongly. They suggested this might be one way asbestos and other mineral fibers could cause cell transformation and cancer.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory experiment on cultured animal cells (in vitro), published as a short communication; results combined from two separate experiments
• Who was studied: Syrian hamster embryo cells (tertiary cultures established from 13-day gestation fetuses); 120 randomly selected anaphases examined in the untreated control group and 120 in the crocidolite-treated group
• Exposure: International Union Against Cancer (UICC) reference crocidolite asbestos at a final dose of 1 microgram per square centimeter of culture surface, given for 12 hours together with hydroxyurea, which was used to synchronize cell division. Earlier studies had shown this dose induces transformation and aneuploidy in these cells.
• Main results:
  • Untreated control cultures: 1 of 120 anaphases (0.8%) was abnormal, containing a single lagging chromosome; no other anaphase abnormalities were seen
  • Crocidolite-treated cultures: 22 of 120 anaphases (18%) had missegregated chromosomes, which the authors describe as a more than 20-fold increase over controls
  • The abnormalities scored were chromosome bridges, sticky chromosomes and lagging chromosomes; many treated anaphases had more than one displaced chromosome
  • Multipolar cell divisions were also seen in treated cultures, but only rarely at this dose
  • In some anaphases of treated cells, asbestos fibers appeared to touch chromosomes, and occasionally chromosomes appeared wrapped around individual fibers
• The authors' conclusion: The authors proposed that physical interaction of asbestos fibers with chromosomes or with structural proteins of the cell-division (spindle) apparatus causes chromosomes to separate wrongly, producing aneuploidy. They stated that these findings provide a mechanism, at the chromosomal level, by which asbestos and other mineral fibers might induce cell transformation and cancer.
• Limitations the authors state:
  • The authors could not determine whether the apparent contacts between fibers and chromosomes occurred in living cells or were an artifact of the fixation procedure

Topics

Medical terms in this study, explained in our Lexicon: Carcinogenesis, Crocidolite, Mineral Fiber.

Related studies

• Induction of metaphase and anaphase/telophase abnormalities by asbestos fibers in rat pleural mesothelial cells in vitro — M. Yegles, L. Saint-Etienne, et al. (1993)
• Role of fibre characteristics on cytotoxicity and induction of anaphase/telophase aberrations in rat pleural mesothelial cells in vitro: correlations with in vivo animal findings — M. Yegles, X. Janson, et al. (1995)
• Metaphase and anaphase analysis of V79 cells exposed to erionite, UICC chrysotile and UICC crocidolite — L.D. Palekar, J.F. Eyre, et al. (1987)
• Detection of aneuploidy-inducing carcinogens in the Syrian hamster embryo (SHE) cell transformation assay — D.P. Gibson, M.J. Aardema, et al. (1995)
• Induction of micronuclei, hyperdiploidy and chromosomal breakage affecting the centric/pericentric regions of chromosomes 1 and 9 in human amniotic fluid cells after treatment with asbestos and ceramic fibers — E. Dopp, M. Schuler, et al. (1997)
• Intracellular protein binding to asbestos induces aneuploidy in human lung fibroblasts — R.A. MacCorkle, S.D. Slattery, et al. (2006)

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