Iron induction of ferritin synthesis and secretion in human hepatoma cell (Hep G2) cultures.

In order to determine if iron was able to stimulate specifically ferritin synthesis and secretion in transformed human hepatocytes in culture, human hepatoma cell (HepG2) cultures were submitted to increasing doses of ferric nitrilotriacetate. Iron uptake by the cells was demonstrated by incorporation of 59 Fe and the staining method of Perls. The following results were obtained: 1. iron incorporation within the hepatocytes increased as a function of culture time; 2. during the first 24 h of treatment, ferritin synthesis increased progressively, in parallel to the iron uptake; 3. a dose-dependent significant stimulation of ferritin synthesis and secretion were observed when the medium iron concentration increased from 5 to 20 mumol/l; 4. albumin, transthyretin and transferrin secretions were unaffected. These data demonstrated that, in our hepatocyte culture model, iron load increased the expression of ferritin in a highly specific manner.