BIOCHEMISTRY AND ENZYME-INDUCTION IN MC-29 VIRUS-INDUCED TRANSPLANTABLE AVIAN HEPATOMA

  • 1 January 1976
    • journal article
    • research article
    • Vol. 36  (7) , 2140-2145
Abstract
For the biochemical characterization of a new transplantable hepatoma derived from the MC-29 virus-induced liver tumor, the macromolecular content and the inducibility of G-6-Pase, G-6-P dehydrogenase and aryl hydrocarbon hydroxylase were compared in chicken liver and this hepatoma. The alteration of the nucleocytoplasmic ratio was deduced from measurements of DNA, RNA, protein and phospholipid contents of the whole cell homogenate and cell fractions. The increased nuclear and decreased cytoplasmic content of macromolecules suggests a dominancy of the nuclei in the tumor cells. G-6-Pase and aryl hydrocarbon hydroxylase activities were lower by 60 and 80%, respectively, in the highly proliferating hepatoma than in the liver. G-6-P dehydrogenase activity increased in the hepatoma. Enzyme inducers, such as methylcholanthrene, hydrocortisone and insulin enhance the activity of these enzymes in the liver but had no stimulating effect on the hepatoma.