Isozyme studies of several enzymes of carbohydrate metabolism in human adult and fetal tissues, tumor tissues, and cell cultures.

The starch gel electrophoretic isozyme patterns of phosphoglucomutase. glucose-6-phosphate dehydrogenase, hexokinase (HK), pyruvate kinase (PK), and lactate dehydrogenase in the cancerous and in the apparently uninvolved regions of livers from human primary hepatoma patients were compared. The HK, PK, and lactate dehydrogenase isozyme patterns in hepatoma were also compared with those in normal adult tissues (liver, mus cle, dura) and fetal tissues (liver, muscle, heart, brain). In addition, other human tumors (esophageal cancer, meningioma, mesothelioma) and cell cultures of tumors (hep atoma, esophageal cancer, HeLa) and fibroblasts were examined. The phosphoglucomutase and glucose-6-phosphate de hydrogenase patterns in hepatoma were similar to those in host livers, except in one case in which the glucose-6phosphate dehydrogenase pattern was altered in the tumor. Hepatoma patterns differed from those of normal liver in that HK II was present, and the proportion of HK III was reduced; the proportion of another form of HK (II,), observed in most of the tissues, was increased in hepa toma. In cell lines of hepatoma and esophageal cancer, the proportion of HK II was increased, compared with the respective tissues of origin. The PK patterns in host livers and hepatomas, although often different from normal liver, were variable, and there were no consistent trends. Several host livers and hepatomas had additional bands (possibly hybrids) between PK L and PK M . All other tumor tissues and cell lines had PK M . The lactate dehydrogenase patterns in hepatoma differed from the liver patterns in only a few cases, when there appeared to be a slight increase in the proportion of H subunits. The proportion of H subunits was also increased in hepatoma cells.