[The effect of thyroid hormones and 5-azacytidine on the gene transcription of malic enzyme and 6-phosphogluconate dehydrogenase].

The effect of thyroid hormones and the methylation inhibitor 5-azacytidine on the level of expression of thyroid hormone-responsive genes (malic enzyme and 6-phosphogluconate dehydrogenase genes) has been studied. DNA-RNA hybridization has shown there is an inverse correlation between the level of DNA methylation and gene expression of malic enzyme and 6-phosphogluconate dehydrogenase. Thus it suggests that the regulation of thyroid hormone gene expression can take place via DNA methylation blocking and that DNA demethylation is part of structural changes essential to the binding of thyroid hormones with DNA elements recognized by thyroid hormone receptors and to further induction of synthesis of specific mRNA.