Growth changes of 3T3 cells in the presence of mineral fibers

Our plain-English summary of Growth changes of 3T3 cells in the presence of mineral fibers, by L. Dumas, M. Pagé (Environmental Research, 1986).

The study

• Authors: L. Dumas, M. Pagé
• Journal: Environmental Research
• Published: 1986;39(1):199-204
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The relationship between exposure to asbestos fibers and the development of mesothelioma or bronchial carcinoma prompted many countries to ban its use from commercial products. The biological mechanism by which asbestos induces or promotes mesothelioma or carcinoma is still unknown. In order to study the influence of fibers on the cell surface, 3T3 fibroblasts were cultured in the presence of various mineral fibers. The acute cytotoxicity produced by mineral fibers was evaluated by the trypan blue dye exclusion method; growth of 3T3 cells was measured as well as the maximum cell density at saturation. We found that growth of 3T3 cells was slower in the presence of chrysotile while light microscopy revealed an increased cellular chromogenicity and a modification of the cell-cell arrangement in the presence of this fiber. We describe an assay in which chrysotile causes an increase in the maximum cell density at saturation.

In plain English

This laboratory study grew mouse fibroblast cells (the 3T3 cell line) in dishes with mineral fibers. No people or animals were studied. In a 4-hour test at 200, 500 or 1000 micrograms per millilitre, the share of cells killed varied widely by material. Canadian 4T30 chrysotile killed the most: 43% at the highest dose, with cell death in fiber-free dishes counted as zero. Other chrysotile samples, attapulgite and glass fiber killed fewer, and crocidolite, glasswool, titanium dioxide and amosite killed the fewest. The authors described attapulgite, an asbestos substitute, as being as cytotoxic as chrysotile. In a longer test using only short 4T30 chrysotile fibers, the cells first grew more slowly. They then reached a higher maximum number per dish: 3.25 to 4.75 million on day 13, against 2.35 million on day 8 without fibers. No piled-up clusters of cells (foci) were seen. The authors concluded the higher density was probably due to a change in how the cells interact with each other. They noted that the early slow-growth result reflects only the first 3 days of contact.

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
• Who was studied: 3T3 mouse fibroblast cells from the American Type Culture Collection, studied at the Department of Biochemistry, Université Laval, Quebec, Canada
• Exposure: Fibers tested: UICC Rhodesian chrysotile A, crocidolite and amosite; Canadian 4T30 chrysotile and attapulgite (both from the Research Institute for Asbestos Development); and, as comparison or control materials, glass fiber (ground GF/C microfilters), glasswool and titanium dioxide. Acute test: 0, 200, 500 or 1000 micrograms per ml for 4 hours. Cell density test: short Canadian 4T30 chrysotile (under 10 micrometres long, 0.2 micrometres in diameter) at 0, 50, 100, 250 and 500 micrograms per ml.
• Main results:
  • In the 4-hour acute test, Canadian chrysotile 4T30 caused the highest cell death: 43% at 1000 micrograms per ml (33% at 500, 19% at 200). These figures are measured with cell death in fiber-free controls taken as 0.
  • Percentage of dead cells at 1000, 500 and 200 micrograms per ml, with fiber-free controls set at 0: attapulgite 28, 26, 11; Canadian chrysotile 27, 20, 4; chrysotile A UICC 24, 23, 9; glass fiber (GF/C filters) 16, 16, 9; crocidolite UICC 12, 15, 5; Pyrex glasswool 9, 5, 1; titanium dioxide 8, 1, 0; amosite UICC 7, 7, 5.
  • The authors reported attapulgite as being as cytotoxic as chrysotile.
  • Without fibers, cells reached a maximum of 2.35 million per dish after 8 days, followed by cell death.
  • With 4T30 chrysotile, cells reached a maximum on day 13 before cell death occurred: 3.25 million per dish at 50 micrograms per ml, 4.75 million at 100, 3.99 million at 250 and 3.70 million at 500.
  • With chrysotile, the authors saw two phases: first slower growth, which they attributed probably to the toxicity of chrysotile, then a higher maximum cell density.
  • The authors stated that the increase in maximum cell density was not observed with glasswool. No data for glasswool in this test are shown.
  • No foci (piled-up clusters of cells) were seen with asbestos fibers under the assay conditions.
  • According to the abstract printed with the article, light microscopy showed increased cell staining (chromogenicity) and a changed cell-to-cell arrangement with chrysotile.
• The authors' conclusion: The authors concluded that the increase in maximum cell density at saturation was probably due to a change in cell-to-cell interaction related to 4T30 chrysotile. They stated this supports the hypothesis that fibers alter contact inhibition and may play a role in cell proliferation leading to transformation.
• Limitations the authors state:
  • The authors noted that the decrease in cell growth represents only the action of the fibers during the first 3 days of contact with the cells.

Topics

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

Medical terms in this study, explained in our Lexicon: Mineral Fiber, Mesothelioma, Carcinoma, Fibroblast, Chrysotile.

Related studies

• 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 — A.M. Sincock, J.D. Delhanty, et al. (1982)
• The presence of simian-virus 40 sequences in mesothelioma and mesothelial cells is associated with high levels of vascular endothelial growth factor — P. Cacciotti, L. Strizzi, et al. (2002)
• 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)
• Src-dependent ERK5 and Src/EGFR-dependent ERK1/2 activation is required for cell proliferation by asbestos — L. Scapoli, M.E. Ramos-Nino, et al. (2004)
• In vitro assays to predict the pathogenicity of mineral fibers — B.T. Mossman, A.M. Sesko (1990)
• Magnetometric evaluation of the effects of man-made mineral fibers on the function of macrophages using the macrophage cell line RAW 264.7 — K. Shibata, Y. Kudo, et al. (2007)

Browse more research in Environmental Research, or return to medical research.