Participation of thyroid hormones in the regulation of the genetic activity of normal and transformed human cells

: It is shown that 125J-thyroid hormones are localized on the structures of the interphasic nucleus and metaphasic chromosomes of cultured fibroblasts of 8--10-day human embryos. At the same time, the labelled thyroid hormones, though localizing in the interphasic nuclei of HeLa cells, are not accepted, unlike normal cells, by their metaphasic chromosomes. It is suggested that during transformation the acceptor ares of the HeLa cells genome lost their property to bind their own receptor complexes with thyroid hormones.