Chromosomal analysis of a diethylnitrosamine-induced tumorigenic and a nontumorigenic rat liver cell line.

A chromosomal analysis was performed on two cell lines which were derived from the liver of two rats exposed to diethylnitrosamine in vivo. The cells were obtained by collagenase perfusion of the liver at an early stage of development of ATPase-deficient putative preneoplastic populations, and propagated from foci of epithelial cells which started growth in vitro. Cell line CL 38 proved to be tumorigenic after transplantation into nude mice, giving rise to hepatocellular carcinomas and metastases. Cell line CL 44 was nontumorigenic after transplantation into nude mice and was therefore considered preneoplastic. The diploid nontumorigenic line CL 44, with a modal number of 42 chromosomes, showed a deletion of chromosome 1 and a translocation of chromosomes 3 and 14 [t(3q12;14q21)]. The hyperdiploid neoplastic cell line CL 38 has a modal chromosome number of 52 and showed tri- or tetrasomy of chromosomes 3, 7, 9, 11, and 12 and a marker chromosome that might have originated from aberrant chromosome 1. One or two homologues of chromosome 3 showed terminal deletions (q42, q41, or q35). In both cell lines rearrangements of chromosome 11 were observed [rob(11q;?) or +11 or -11 or del(11)(q12)]. Some of these karyotype abnormalities are located on the same chromosome as described for transplantable hepatomas and for other chemically induced tumors of the rat.