Pleuro-pulmonary tumours detected by clinical and chest X-ray analyses in rats transplanted with mesothelioma cells

Our plain-English summary of Pleuro-pulmonary tumours detected by clinical and chest X-ray analyses in rats transplanted with mesothelioma cells, by F. Le Pimpec-Barthes, I. Bernard, I. Abd Alsamad, et al (British Journal of Cancer, 1999).

The study

• Authors: F. Le Pimpec-Barthes, I. Bernard, I. Abd Alsamad, A. Renier, L. Kheuang, J. Fleury-Feith, P. Devauchelle, F. Quintin Colonna, M. Riquet, M.C. Jaurand
• Journal: British Journal of Cancer
• Published: 1999;81(8):1344-50
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

New strategies for cancer therapy must be developed, especially in severe neoplasms such as malignant pleural mesothelioma. Animal models of cancer, as close as possible to the human situation, are needed to investigate novel therapeutical approaches. Orthotopic transplantation of cancer cells is then relevant and efforts should be made to follow up tumour evolution in animals. In the present study, we developed a method for the orthotopic growth of mesothelioma cells in the pleural cavity of Fischer 344 and nude rats, along with a procedure for clinical survey. Two mesothelioma cell lines, of rat and human origin, were inoculated by transthoracic puncture. Body weight determination and chest X-ray analyses permitted the follow-up of tumour evolution by identifying different stages. Autopsies showed that tumours localized on the whole pleural cavity (diaphragm, parietal pleura), mediastinum and pericardium. Tumour morphology and antigenic characteristics were consistent with those of the inoculated cells and were similar in both types of rats inoculated with the same cell type. These results demonstrate that mesothelioma formation in rats can be followed up by clinical and radiographic survey after gentle intrathoracic inoculation of mesothelioma cells, thus allowing the definition of stages of interest for further experimental trials.

In plain English

In this animal experiment, the authors injected mesothelioma cells into the chest (pleural) cavity of rats by needle, without surgery. The rat cells came from a pleural mesothelioma induced in Fischer 344 rats by 20 mg of crocidolite fibres; a human line (DEVy) was also used. Three groups of six Fischer 344 rats received 5, 3 or 1 million rat cells. Eleven nude (immune-deficient) rats received 3 million rat cells, four received salt solution only, and three received human cells. Rats given 5 or 3 million cells lost significant weight between days 24 and 31, and their X-ray scores rose significantly from day 15 to 30. In rats given 1 million cells these changes were not statistically significant, though X-rays showed tumour progression by day 43. In nude rats, X-ray abnormalities appeared by day 22 in seven of 11 treated rats. Autopsies found tumours mainly in the mediastinum and pericardium, also involving the diaphragm, sometimes extending into the lungs; no visceral metastases were found. The authors concluded that this method, with follow-up by weight and X-ray, was a useful tool for mesothelioma research.

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 developing a model in which mesothelioma cells are transplanted into the pleural cavity of rats and followed by body weight and chest X-ray
• Who was studied: Three groups of six Fischer 344 rats (18 rats) were given rat mesothelioma cells. In addition, 11 nude rats were given rat mesothelioma cells, four sham nude rats were given phosphate-buffered saline only, and three nude rats were given the human mesothelioma cell line DEVy. The work was done in France.
• Exposure: Mesothelioma cells were injected into the right pleural cavity. The rat cells came from pleural mesothelioma induced in Fischer 344 rats by intrapleural inoculation of 20 mg of crocidolite fibres. Fischer 344 rats received 5 million (group I), 3 million (group II) or 1 million (group III) cells. Nude rats received 3 million rat cells, and three nude rats received human DEVy mesothelioma cells.
• Main results:
  • In Fischer 344 rats, body weight fell significantly between 24 and 31 days in group II (P = 0.044) and group I (P = 0.015). There was no significant change in group III (P = 0.73).
  • In nude rats given rat cells, body weight decreased between 20 and 33 days (P = 0.0096), while sham rats kept gaining weight. The difference in body weight between treated and sham nude rats was not statistically significant.
  • In Fischer 344 rats, mean chest X-ray scores (scale 0 to 3) after 15 days were 0.25, 0 and 0.5 in groups III, II and I. After 30 days they reached 1.2, 2.25 and 2.5.
  • In Fischer 344 rats, the increase in X-ray scores between 15 and 30 days was significant in group II (P = 0.005) and group I (P = 0.0012). It was not significant in group III (P = 0.051).
  • In group III (1 million cells), chest X-rays also showed tumour progression at the end of the experiment (day 43). The changes were more limited than in the other groups, and no individual score reached 3.
  • In nude rats given rat cells, chest X-ray abnormalities were seen 22 days after inoculation in seven of 11 rats. By 29 days every treated rat scored 1 or more, while sham rats had normal X-rays.
  • At autopsy, all Fischer 344 rats had massive tumours mainly invading the mediastinum and pericardium and involving the diaphragm. Extension to the lungs was occasionally found, but no metastases were found in the visceral organs.
  • Tumours in nude rats given the human cell line were consistent with epithelial malignant mesothelioma.
• The authors' conclusion: The authors concluded that gentle injection of mesothelioma cells into the rat pleural cavity, followed by clinical survey (body weight and chest X-ray), is a relevant and useful tool for malignant mesothelioma research in both immunocompetent and immune-deficient rats.
• Limitations the authors state:
  • Only a limited number of nude rats (three) were inoculated with the human mesothelioma cell line.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Chest X-Ray, Mesothelioma, Neoplasm, Pleural Mesothelioma, Pleural Cavity, Diaphragm, Parietal Pleura, Mediastinum.

Related studies

• Treatment of transplanted rat tumours with double-stranded RNA(BRL 5907). II. Treatment of pleural and peritoneal growths — M.V. Pimm, R.W. Baldwin (1976)
• Apparent synergy between chrysotile asbestos and N-nitrosoheptamethyleneimine in the induction of pulmonary tumours in rats — P.T. Harrison, J.C. Heath (1988)
• Failure to demonstrate tumour-associated transplantation antigens on asbestos-induced mesotheliomas in rats — D.G. Brown, J.C. Wagner, et al. (1980)
• Progressive growth of a human pleural mesothelioma xenografted to athymic rats and mice — C.J. Lindén, L. Johansson (1988)
• Characteristics of tumors and tumor cells cultured from experimental asbestos-induced mesotheliomas in rats — J.E. Craighead, N.J. Akley, et al. (1987)
• Histology and ultrastructure of serially transplanted rat mesotheliomas — J.C. Wagner, N.F. Johnson, et al. (1982)

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