[Stimulation with triiodothyronine of the synthesis of DNA, total proteins, nuclear proteins and nuclear matrix proteins in cultured cells of hepatoma Morris 7777].

Intensity of DNA and protein biosynthesis was decreased in Morris hepatoma 7777 cultivated cells in absence of thyroid hormones. Physiological concentrations of triiodothyronine increased synthesis of DNA and total proteins after lag phase within 12-48 hrs, while synthesis of nuclear and nuclear matrix proteins was stimulated already within 2 hrs. This suggests that stimulation of nuclear proteins biosynthesis occurred prior to the hormone effect on proliferation and cell metabolism. Alterations in sensitivity of chromatin to DNAase I were not observed. Response of the Morris hepatoma cells to thyroid hormones may be used in studies of molecular mechanisms of thyroid hormones action.