Clonal behavior of a rat liver cell line and its modification by repeated treatments with a carcinogenic polycyclic hydrocarbon.

A rat liver cell line, Lew A1, was isolated from W/LEW rats. It had the normal female karyotype in the lower passage numbers, but in the higher passages it was aneuploid. This line was passaged 65 times, produced rat serum albumin, and consisted of an apparently homogeneous population of typical epithelial cells. The cells also had high levels of the inducible aryl hydrocarbon hydroxylase enzyme complex. A series of experiments described here defined the normal clonal behavior of this line and its modification by repeated treatments with a carcinogenic polycyclic hydrocarbon, 7,12-dimethylbenz[a]anthracene. The results were discussed with particular reference to metastasis, preneoplastic changes, and neoplastic progression.