The cellular DNA content and profile of dimethyl nitrosamine induced marine lung tumors in relation to their histopathology.

A total of 61 lung tumors induced in NMRI mice by the carcinogen dimethyl nitrosamine were classified as solid adenomas or papillary tumors. Single cell suspensions from each of these tumors were analyzed by flow cytometry according to DNA content. The adenomas contained stemlines having a diploid DNA content, a finding which is in accordance with the benign nature of these tumors. In the papillary tumors heteroploid stemlines were often found in addition to diploid cells, this seems to be a sign of their malignant properties. The significance of the heteroploidy and the clustering of stemlines at the near diploid and the tetraploid levels in these tumors is discussed.