GROWTH-STIMULATION OF FERRITIN OF HUMAN LEUKEMIA-CELLS IN-VITRO

Ferritin has been reported to inhibit the growth of some leukemia cell s in serum-supplemented culture. Recently we have found that ferritin stimulates the proliferation of human acute myeloblastic leukemia cell s HL-60 and erythroleukemia cells K-562-T1 in serum-free medium. In th is study, we examined the effect of ferritin against 14 human leukemia cell lines using human heart ferritin in serum-depleted culture mediu m. Among 14 cell lines tested, 10 were stimulated to proliferate by fe rritin (maximum response at 30-300 ng/ml) with 0-1% fetal calf serum ( FCS). The growth of all the cell lines was significantly inhibited by ferritin in the presence of 10% FCS. These results suggest that ferrit in has dual functions; it promotes the growth of leukemia cells with l ow concentration of FCS, but suppresses their growth with high concent rations of FCS.