Analysis of genetically defined liver enzymes in transplantable hepatomas and developing liver of the mouse

The activities and isozyme patterns of seven enzymes involved in glycolysis, the malate-aspartate shuttle and the pentose phosphate pathway have been examined in five transplantable murine hepatomas, adult liver and fetal liver. The liver marker enzyme, alcohol dehydrogenase, has also been studied. The developmental expression of the activity and isozyme pattern of these enzymes have been determined. Seven defined loci on six different chromosomes code for these enzymes and isozymes. The tumors express no unique gene product for any of the enzymes examined, but the activities of all the enzymes in the hepatomas are more like fetal liver than adult liver, regardless of whether activities are increased or decreased in hepatomas. The activity of one enzyme is unchanged in hepatomas, and this enzyme has the same activity in fetal and adult liver. The enzyme activities in the five hepatomas vary more than the enzyme activities in liver and fetal liver of the three inbred strains of mice examined.