Chromatin solubilization in rapidly growing hepatomas

Abstract

The presence of substantial amounts of DNA in the cytosol fractions prepared from rapidly growing transplanted rat hepatomas was confirmed. Agarose gel electrophoresis of this DNA from the Morris hepatomas 7288CTC, 7777, and 7800 suggested that it corresponds primarily to nucleosome monomers with smaller amounts of nucleosome dimers and trimers. Despite the evidence for solubilization of chromatin in rapidly growing hepatomas the potential DNA endonuclease activity was less in nuclei from these tumors than in nuclei from more slowly growing hepatomas or host livers. It was suggested that focal necrosis in rapidly growing solid tumors may be associated with the influx of divalent cations and the activation of DNA endonuclease activity.