C-type and intracisternal A-type virus particles during epidermal carcinogenesis by tobacco smoke condensate in BALB/c mice

Abstract

Summary.-Electron microscopic observations of sequential stages of skin carcinogenesis induced by tobacco smoke condensate (SC) and a cyclohexane fraction of tobacco smoke condensate (G) revealed an increase in incidence of intracisternal A particles within the epidermal cells. Tumours induced by SC also contained C-type particles, but these were not seen in G-induced tumours or after irritant or solvent treatment. There was no evidence of an increase in intracisternal A particles after irritant or solvent treatment. A direct relationship between the proliferation of A particles and neoplastic growth of BALB/c mouse epidermis appears likely. The data suggest possible activation of a latent C -type virus by SC.

The Specificity of Early Changes in the Skin During Carcinogenesis

“…Similar observations were made in BALB/c mouse skin tumours induced by polycyclic hydrocarbon treatment (Bibby & Smith, 1975). A further study (Bibby & Smith, 1977b) has revealed the presence of C-type viruses budding from cell membranes in squamous cell carcinomas induced in BALB/c mouse skin by painting with tobacco smoke condensate. These results suggest a possible activation of an RNA oncogenic virus by chemical carcinogens.…”