Cytogenetic and pathogenic effects of long and short amosite asbestos

Our plain-English summary of Cytogenetic and pathogenic effects of long and short amosite asbestos, by K. Donaldson, N. Golyasnya (The Journal of Pathology, 1995).

The study

• Authors: K. Donaldson, N. Golyasnya
• Journal: The Journal of Pathology
• Published: 1995;177(3):303-7
• Cited by: 19 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

This study utilized two samples of amosite asbestos which differ in their length, but not in their diameter and which have been shown previously to have very different abilities to cause pathology in rats exposed by instillation or inhalation. The activity of these amosite samples in causing chromosomal aberrations in Chinese hamster ovary cells in culture was examined, along with the effect of the glutathione (GSH) synthesis-inhibiting agent buthionine sulphoximine. The incidence of chromosomal aberrations in cells treated with the short fibre sample was similar to control levels; the long amosite sample caused significantly more chromosomal aberrations than the short fibre sample. When cells were treated with buthionine sulphoximine to decrease the levels of intracellular glutathione, the incidence of chromosomal aberrations was increased in the control cells, but also on treatment with both short and long amosite, the long sample again being considerably more active than the short. The pathogenicity of the long amosite may result from the ability of the fibres to cause chromosome damage, while the enhancement of this damage caused by decreasing intracellular glutathione suggests that the asbestos fibres may impose an oxidant stress on the cells which contributes to these aberrations.

In plain English

This laboratory study tested whether two samples of amosite asbestos, one with long fibres and one with short fibres, damaged the chromosomes of Chinese hamster ovary cells grown in culture. The short sample had been made from the long one by milling and contained far fewer long fibres. Cells treated with short amosite did not differ significantly from untreated cells in chromosomal aberrations (6.3 per cent versus 4.5 per cent of cells). Long amosite produced significantly more aberrations (12.1 per cent of cells). It also produced more hyperploid cells (cells with extra chromosomes) and a lower proportion of dividing cells. The authors then lowered the cells' glutathione, a natural antioxidant, with the drug buthionine sulphoximine. With this drug, aberrations rose significantly in cells given no amosite (from 4.5 to 9.0 per cent), in short-amosite cells (from 6.3 to 16.2 per cent) and in long-amosite cells (from 12.1 to 18.4 per cent). The authors concluded that the amount of chromosome damage paralleled the two samples' pathogenic potential. They noted that because the cells were in continuous culture, the role of these changes in cancer could not be tested.

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 cell-culture (in vitro) experiment
• Who was studied: Chinese hamster ovary (CHO) cells in culture. Chromosomes were assessed in 200 metaphases in each of three separate experiments.
• Exposure: Long and short amosite asbestos at 10 micrograms per ml for 48 hours. The short sample was made from the long one by milling. In the long sample, 70 per cent of fibres were longer than 10 micrometres and 40 per cent were longer than 20 micrometres. In the short sample, less than 10 per cent of the fibrous material was longer than 10 micrometres and none was longer than 20 micrometres. Some cultures were also treated with buthionine sulphoximine (100 micrograms per ml) to lower glutathione.
• Main results:
  • Without buthionine sulphoximine, the percentage of cells with chromosomal aberrations did not differ significantly between untreated control cells (4.5) and short-amosite cells (6.3).
  • Long amosite produced significantly more chromosomal aberrations than short amosite: 12.1 per cent of cells versus 6.3 per cent. It also produced more hyperploid cells: 9.5 per cent versus 5.7 per cent in short-amosite cells and 3.3 per cent in controls.
  • The mitotic index was significantly lower in long-amosite cells (4.5) than in short-amosite cells (6.3). It was 7.5 in controls.
  • The aberrations seen included breaks, acentric fragments, dicentric chromosomes, translocations, ring chromosomes and chromatid exchanges.
  • With buthionine sulphoximine, the percentage of cells with chromosomal aberrations was significantly higher than without it in every group. In control cells given no amosite it was 9.0 with the drug versus 4.5 without. In short-amosite cells it was 16.2 versus 6.3. In long-amosite cells it was 18.4 versus 12.1.
• The authors' conclusion: The authors concluded that the number of chromosomal aberrations in cultured cells paralleled the pathogenic potential of the two samples, with the long sample substantially more potent than the short.
• Limitations the authors state:
  • Because the cells were in continuous culture, the authors could not test whether these chromosome changes play a role in malignancy.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Amosite.

Medical terms in this study, explained in our Lexicon: Amosite, Pathology, Glutathione (GSH).

Related studies

• Long and short fiber amosite asbestos alters at a different extent the redox metabolism in human lung epithelial cells — C. Riganti, E. Aldieri, et al. (2003)
• Cytogenetic response to asbestos fibers in cultured human primary mesothelial cells from 10 different donors — K. Pelin, A. Hirvonen, et al. (1995)
• Differential release of superoxide anions by macrophages treated with long and short fibre amosite asbestos is a consequence of differential affinity for opsonin — I.M. Hill, P.H. Beswick, et al. (1995)
• Chemical differences between long and short amosite asbestos: differences in oxidation state and coordination sites of iron, detected by infrared spectroscopy — A. Graham, J. Higinbotham, et al. (1999)
• High aspect ratio materials: role of surface chemistry vs. length in the historical "long and short amosite asbestos fibers" — M. Tomatis, F. Turci, et al. (2010)
• Distinct Pro-Inflammatory Mechanisms Elicited by Short and Long Amosite Asbestos Fibers in Macrophages — R. Leinardi, J.R. Petriglieri, et al. (2023)

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