Isozymic forms of some energy metabolism enzymes during oncovirus-induced cell transformation

Kinetic studies of changes in isozymic forms of hexokinase, lactate and malate dehydrogenase and in total hexokinase activity during viral carcinogenesis were carried out. The test systems were rat embryo fibroblasts infected with an oncogenic variant of human adenovirus type 12 and an infectious adenovirus type 6, intact REF cultures in different stages of growth (log and stationary phase), and hamster sarcoma A12 and rat reticulosarcoma 321-RRS cell cultures. Molecular isozymic forms of the stated enzymes and total hexokinase activity in the nuclear fraction and cytoplasm of cells in culture were investigated. It was shown that infectious and oncogenic viruses evoked a rearrangement in the spectrum of the energy metabolism enzymes in the nucleus and cytoplasm. The changes appeared in the first days of the contact of REF culture with the virus, and were more pronounced after the oncogenic rather than the infectious virus. The analysis of changes in isozymic forms of the enzymes under study in virus A12-infected REF cultures and in hamster sarcoma A12 and reticulosarcoma 321-RRS cells growing in vitro revealed that they had some features in common. The most pronounced changes were found with hexokinases. The changes described can serve as objective signs of cell transformation.