Tests for Viral Agents in Bronchiolar Cell Carcinomas in Mice

Our plain-English summary of Tests for Viral Agents in Bronchiolar Cell Carcinomas in Mice, by W.E. Smith, L. Miller (1965).

The study

• Authors: W.E. Smith, L. Miller
• Published: Third Quadrennial International Conference on Cancer, June 24-29 1965
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This short conference paper reported an animal experiment in mice. It does not mention asbestos. The authors had implanted minced fetal BALB/c mouse lung, together with the carcinogen 20-methylcholanthrene, into the thigh muscles of adult mice. Tumors arising in two mice were transplanted serially into young adult female BALB/c mice, forming two lines, LC 9 and LC 10, diagnosed as adenocarcinomas of bronchiolar cell type. Both tumors spread widely. Mice carrying them showed proliferation and polypoid growth of mesothelial cells of the visceral pleura, which the authors said may have been secondary to lung metastases. To look for a virus, the authors injected filtered tumor extracts into newborn BALB/c mice. Nothing remarkable was found in 20 mice given filtrates of tumors from the legs. Of 16 mice given filtrates of lungs containing LC 10 metastases, three had kidney, liver or lung lesions not seen in 96 untreated control mice. The authors concluded the findings suggest a viral agent, tentatively called the M 10 agent, possibly a strain of polyoma virus. Further injected animals were still being followed.

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 (serial tumor transplantation in mice and injection of filtered tumor extracts into newborn mice)
• Who was studied: BALB/c mice: two transplantable tumor lines (LC 9, LC 10) carried in young adult female BALB/c mice; newborn BALB/c mice injected with filtrates; 96 untreated BALB/c control mice necropsied at ages 9 to 12 months
• Exposure: Tumors originally induced by implanting minced fetal BALB/c lung with 20-methylcholanthrene; filtered extracts of these transplanted tumors, or of lungs containing their metastases, injected into newborn mice. No asbestos exposure was studied.
• Main results:
  • LC 9 (carried through 30 transplant generations): host mice had metastases in lungs, lymph nodes, liver, heart and skeletal muscles, with proliferation and sometimes polypoid growth of mesothelial cells of the visceral pleura
  • LC 10 (carried through 60 transplant generations): host mice had metastases in lungs, lymph nodes, liver and kidneys, with proliferation and polypoid growth of mesothelial cells of the visceral pleura
  • 20 mice injected with filtrates of LC 9 or LC 10 tumors taken from transplant sites in the legs, examined at 9 to 12 months: nothing remarkable was found
  • 16 mice injected with filtrates of lungs containing LC 10 metastases, necropsied 9 to 12 months later: three showed lesions not found in the 96 control mice
  • Of these three mice, one had at least six renal cortical adenomas, 23 kidney cysts and 11 liver cysts; one had a renal cortical adenoma, 13 kidney cysts and a liver largely replaced by cysts; one had extensive hypertrophy and hyperplasia of bronchial epithelium and alveolar lining cells, with some lobes largely filled with adenomatoid tissue
• The authors' conclusion: The authors concluded that their findings suggest a viral agent in the transplanted tumors, which they tentatively called the M 10 agent and which may prove to be a strain of polyoma virus
• Limitations the authors state:
  • The authors noted that the pleural mesothelial proliferation may have been secondary to metastases in the lungs rather than caused by a virus
  • The work was preliminary: injected mice were still being followed, and additional groups of newborn mice and hamsters had been injected but not yet evaluated

Topics

Medical terms in this study, explained in our Lexicon: Carcinoma, Adenocarcinoma, Mesothelial Cells, Visceral Pleura.

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