The potential usefulness of a differentiating teratocarcinoma cell line in in vitro toxicity testing.

A number of in vitro systems have been put forward as potential alternative methods for testing chemicals for teratogenic potential. The most promising of these systems, for example mammalian whole embryo culture and the micromass technique, are currently undergoing further interlaboratory validation. However, such tests involve the use of a considerable number of animals. It was therefore decided to investigate the possible use of a permanent cell line that possessed many of the properties of embryonic cells, that is a differentiating cell line, F9 (derived from a mouse teratocarcinoma), in the development of an in vitro teratogenicity test. In a preliminary study, six chemicals were tested for their modulating effects on differentiation in undifferentiated, differentiating and differentiated F9 cells. These effects were assessed morphologically and by measuring the production of laminin (a biochemial marker of F9 differentiation). The use of the F9 cell line in in vitro teratogenicity testing shows promise, but further work is necessary before its potential can be fully evaluated.