Perinatal lung carcinogenesis in mice: in vivo and in vitro correlation

Perinatal lung carcinogenesis in susceptible (A) and resistant (C57B1/6J) to lung carcinogenesis mice was studied in (1) experiment in vivo and (2) in organ cultures of embryonic lung exposed to carcinogens directly (in vitro) or transplacentally (in utero): females were treated with carcinogens at 17-19 days of pregnancy, killed 1-2 days after the treatment and embryonic lungs were explanted in organ cultures. Transplacental and direct (in vitro) treatment with urethane and benz(a)pyrene (BP) induced in the explants: (1) stimulation of epithelial and mesenchymal cell proliferation; (2) increase of viability and survival as compared to the non-treated explants (growth stimulating effect); (3) morphological lesions (hyperplasia and squamous-cell metaplasia of epithelium, adenomatous growth and adenoma-like structures). All the alterations developed in treated lung explants depended both on host factors and carcinogenic treatment (type of carcinogen, dose, method of exposure, and duration of cultivation).