Some antigenic similarity between nonhistone protein-DNA complexes from chromatin of the cells of Zajdela hepatoma and liver of rats subjected to a single 4-dimethylaminoazobenzene injection.

A comparative study of the antigenic properties of the nonhistone protein (NHP)-DNA complexes, isolated from liver and kidney chromatin of intact rats and from Zajdela hepatoma cells, revealed in the latter the presence of an antigenic component characteristic of kidney chromatin but never occurring in the liver chromatin of intact rats. A similar antigenic component is found in rat liver 4--7 days following a single injection of the hepatocarcinogen 4-dimethylaminoazobenzene and is not observed after an injection of the non-carcinogenic analogue 4-diethylaminoazobenzene. It is noteworthy, that this chromatin alteration resulting from carcinogen treatment is temporary, since on the 11th day following such treatment the kidney antigen is no longer found.