Studies on the morphological patterns of asbestos induced mesotheliomas in vivo and in vitro

Our plain-English summary of Studies on the morphological patterns of asbestos induced mesotheliomas in vivo and in vitro, by I.P. Gormley, R.E. Bolton, G. Brown, et al (Carcinogenesis, 1980).

The study

• Authors: I.P. Gormley, R.E. Bolton, G. Brown, J.M. Davis, K. Donaldson
• Journal: Carcinogenesis
• Published: 1980;1(3):219-31
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Cell lines were established in vitro from five peritoneal mesotheliomas produced in rats by the injection of crocidolite asbestos. These tumours exhibited the previously described diverse range of histological patterns normally associated with mesotheliomas. This diversity of appearance was also evident in culture but cell patterns in vitro did not necessarily correspond to the histology of the original tumour. With increased time in culture most cell lines tended towards a pattern of random orientation associated with the piling up of cells to form discrete masses. Despite this variation in cell pattern in culture, few ultrastructural differences were seen during electron microscope examination. Following varying periods in culture, some cell lines from these tumours were injected into either rats or athymic mice. Only one typical rat mesothelioma was produced but all cell lines produced tumours in athymic mice. The implications of these findings are discussed in relation to the aetiology of asbestos induced mesotheliomas.

In plain English

This was an animal and laboratory (cell culture) experiment. Male Wistar rats of the AF/HAN strain were given a single injection of 25 mg of UICC crocidolite asbestos into the abdomen at three months of age. The authors grew cell lines from five of the resulting peritoneal mesotheliomas and compared the cultured cells with the original tumours. The cultured cells did not necessarily resemble the tumour they came from. Tumour 5 first grew as flattened, mesothelial-like cells, while tumour 3 grew as fibroblast-like cells. Cells from 4 of the 5 tumours piled up into masses. Under the electron microscope the cell lines showed relatively few differences. When cells were injected back into rats, one rat developed a typical peritoneal mesothelioma five and a half months later. Two other rats developed sarcomas that could not be classified with certainty as mesotheliomas. Cell lines from all five tumours were injected into athymic nude mice, and all lines from tumours 4 and 5 were invasive. The authors suggested that mesothelioma cells may originate from connective tissue stem cells.

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: Animal experiment with cell culture (in vitro) and re-injection of cultured tumour cells into rats and athymic nude mice
• Who was studied: Male random-bred Wistar rats (AF/HAN strain). Cell lines were grown from peritoneal mesotheliomas in five of these rats. Cells were later injected into isologous rats and into six-week-old athymic nude mice. Institute of Occupational Medicine, Edinburgh.
• Exposure: A single intraperitoneal injection of 25 mg of UICC crocidolite asbestos in 1 ml of phosphate buffered saline, given at three months of age; the first tumours were found nine months after injection
• Main results:
  • Cultured cells did not match the original tumour's appearance. Tumour 5, a fibrosarcomatous tumour, first produced flattened mesothelial-like cells. Tumour 3 grew as fibroblast-like cells.
  • Tumour 5 cultures initially consisted of flattened cells resembling normal mesothelial cells
  • Cells piled up to form masses in cultures from 4 of the 5 tumours
  • Electron microscopy showed relatively few differences in cell structure among the cell lines
  • In re-injected rats, one rat given a tumour 4 cell line (cultured for six months) developed a typical peritoneal mesothelioma five and a half months after injection
  • Two other re-injected rats developed sarcomas, as much as two years after injection
  • In athymic mice, all mice injected with cell lines from tumours 1 and 2 died within five weeks
  • In athymic mice, some animals given tumour 3 cell lines died as early as four weeks after injection, with blood-stained ascites
  • In athymic mice, all cell lines from tumour 4 were invasive
  • In athymic mice, all cell lines from tumour 5 were invasive
• The authors' conclusion: The authors suggested that mesothelioma cells originate from the transformation of multi-potential connective tissue stem cells
• Limitations the authors state:
  • Because the rat strain was random-bred, tissue compatibility problems would have been expected to prevent all but the most malignant tumours from growing after re-injection
  • The two late sarcomas in re-injected rats could not be classified with certainty as mesotheliomas, so the authors said the finding should be treated with caution

Topics

The National Library of Medicine indexes this study under subjects our site covers: Crocidolite, Mesothelioma, Peritoneal mesothelioma.

Medical terms in this study, explained in our Lexicon: Mesothelioma, Peritoneal Mesothelioma, Crocidolite, Histology.

Related studies

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• Early mesothelial cell proliferation after asbestos exposure: in vivo and in vitro studies — I.Y. Adamson (1997)
• mRNA expression patterns in different stages of asbestos-induced carcinogenesis in rats — H. Sandhu, W. Dehnen, et al. (2000)
• Change of heme oxygenase-1 expression in lung injury induced by chrysotile asbestos in vivo and in vitro — H. Nagatomo, Y. Morimoto, et al. (2007)
• Hemizygosity of Nf2 is associated with increased susceptibility to asbestos-induced peritoneal tumours — J. Fleury-Feith, C. Lecomte, et al. (2003)
• Experimental results using 3-bromopyruvate in mesothelioma: in vitro and in vivo studies — P. Icard, X.D. Zhang, et al. (2012)

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