A comparison of the cytogenetic response to asbestos and glass fibre in Chinese hamster and human cell lines. Demonstration of growth inhibition in primary human fibroblasts

Our plain-English summary of A comparison of the cytogenetic response to asbestos and glass fibre in Chinese hamster and human cell lines. Demonstration of growth inhibition in primary human fibroblasts, by A.M. Sincock, J.D. Delhanty, G. Casey (Mutation Research, 1982).

The study

• Authors: A.M. Sincock, J.D. Delhanty, G. Casey
• Journal: Mutation Research
• Published: 1982;101(3):257-68
• Cited by: 41 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Asbestos and fine glass fibre, which induce high levels of chromosome aberrations and polyploidy in Chinese hamster permanent cell lines, were found to cause no increase in chromosome damage or polyploidy in primary human fibroblasts or in human lymphoblastoid lines. In common with permanent cell lines of hamster or human origin, treatment of primary human fibroblasts with higher doses of asbestos or fine glass resulted in almost total growth inhibition, showing that the primary cells are not unaffected by these agents. The reason for lack of evident cytogenetic damage in primary cells may lie in the greater spontaneous karyotype instability of transformed (permanent) cell lines or may be connected with the less efficient DNA repair capacity of Chinese hamster ovary cells.

In plain English

This laboratory study compared how cultured cells responded to asbestos and glass fibre. The authors exposed Chinese hamster ovary cells (CHO-K1), primary human fibroblasts and two human lymphoblastoid lines to UICC crocidolite, superfine Canadian chrysotile, and fine (code 100) and coarse (code 110) Johns Manville glass fibres. In the hamster cells, after 48 hours at 0.01 mg/ml, 30% of cells were abnormal with crocidolite and 32% with chrysotile, against 4% in controls. Glass 100 caused less damage, though still well above control levels; glass 110 produced no increase in chromosome damage. In 16 experiments on 5 human fibroblast lines, and in the lymphoblastoid lines, no significant chromosome damage above control levels was found. At 0.05 and 0.1 mg/ml, chrysotile and glass 100 left adult human fibroblasts with very little increase in cell number over 4 days, without appreciable cell death. Foetal fibroblasts were somewhat less affected. Glass 110 had no effect on growth. The authors suggested the difference might reflect the unstable chromosomes of permanent hamster lines or better DNA repair in human cells. They noted that without electron microscopy they could not compare fibre uptake between cell types.

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 (in vitro) cell culture experiment comparing chromosome damage and cell growth after exposure to asbestos and glass fibre
• Who was studied: Cultured cells, not people. For chromosome studies: Chinese hamster ovary (CHO-K1) cells, 5 primary human fibroblast lines and 2 human lymphoblastoid lines. The cells included lines from people with a genetic predisposition to cancer and from people with ataxia telangiectasia. For growth experiments: normal adult (77LO) and foetal (59LO) human fibroblasts. The work was done at the Galton Laboratory, University College London.
• Exposure: UICC crocidolite and S.F.A. chrysotile (a superfine sample from a Canadian mine). Johns Manville glass fibres code 100 (fine) and code 110 (coarse). Chromosome studies used 0.01 to 0.1 mg/ml for 48 or 72 hours. Growth experiments used 0.05 and 0.1 mg/ml of chrysotile and glass 100 and 110, followed over 4 days.
• Main results:
  • In CHO-K1 hamster cells after 48 hours at 0.01 mg/ml, abnormal cells were 4% in controls, 30% with crocidolite, 32% with chrysotile, 2% with glass 110 and 24% with glass 100. Polyploid cells were 1%, 29%, 35%, 6% and 1% respectively.
  • In the hamster cells, glass 100 produced a lower level of chromosome damage than asbestos, though still well above control level. Coarse glass 110 produced no increased chromosome damage.
  • In primary human fibroblasts (16 experiments on 5 lines), no significant chromosome damage above control levels was found.
  • In the 2 human lymphoblastoid lines, there was no increased chromosome damage, and polyploidy and micronuclei stayed at control levels.
  • In adult human fibroblasts, chrysotile or glass 100 at 0.05 or 0.1 mg/ml resulted in very little increase in cell number over 4 days.
  • Foetal fibroblasts showed some increase in cell number with these agents, but considerable inhibition was still evident. Coarse glass 110 had no effect on growth of either adult or foetal fibroblasts.
  • Viability showed no appreciable cell death. Lowered cell numbers with chrysotile or glass 100 appeared to come from growth inhibition, with lowered mitotic indices.
• The authors' conclusion: The authors concluded that the primary human cells were not unaffected, since higher doses almost totally inhibited growth. They suggested that the lack of evident chromosome damage in primary cells may relate to the greater spontaneous chromosome instability of permanent (transformed) cell lines, or to the less efficient DNA repair of Chinese hamster ovary cells.
• Limitations the authors state:
  • Without electron microscopy, the authors could not compare how much fibre was taken up by human fibroblasts versus hamster cells, which may matter.

Topics

Medical terms in this study, explained in our Lexicon: Fibroblast.

Related studies

• Sister-chromatid exchange and cell kinetics in CHO-K1 cells, human fibroblasts and lymphoblastoid cells exposed in vitro to asbestos and glass fibre — G. Casey (1983)
• Cytotoxicity and multinucleate giant cell formation in Chinese hamster lung fibroblast caused by crocidolite and chrysotile — Y.C. Hong, S.S. Choi (1997)
• Effects of asbestos fibers on cell division, cell survival, and formation of thioguanine-resistant mutants in Chinese hamster ovary cells — K. Kenne, S. Ljungquist, et al. (1986)
• Genotoxicity and cytotoxicity of multi-wall carbon nanotubes in cultured Chinese hamster lung cells in comparison with chrysotile A fibers — M. Asakura, T. Sasaki, et al. (2010)
• Light microscope studies on the effects of chrysotile asbestos and fiber glass on the morphology and reticulin formation of cultured lung fibroblasts — R.J. Richards, F. Jacoby (1976)
• Differences in the sensitivity of hamster and rat lung cells exposed in vitro to natural and man-made fibres — M. Aufderheide, J.W. Knebel, et al. (1996)

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