Iron regulation of transferrin synthesis in the human hepatoma cell line HepG2.
In human beings, serum transferrin levels increase during iron deficiency and decrease with iron overload. Yet, whether or not iron levels actually affect the synthesis of transferrin in human liver cells is not known. In previous studies, iron was shown to suppress the expression of chimeric human transferrin genes in livers of transgenic mice. The goal of this study was to determine if iron suppresses intact endogenous human transferrin synthesis by testing the effects of changes in iron levels on synthesis of transferrin in a human hepatoma cell line HepG2. In HepG2 cells, normalized(35)S-metabolically labeled transferrin synthesis was consistently less following iron treatment with hemin or ferric citrate, than following treatment with an iron-chelator deferroxamine. Thus, this study provides new evidence that iron can regulate synthesis of intact endogenous human transferrin.
Barnum-Huckins
K
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Department of Cellular and Structural Biology, The University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78284, USA.
Adrian
G S
GS
D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D003676:Deferoxamine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005290:Ferric Compounds / Q000494:pharmacology; D006427:Hemin / Q000494:pharmacology; D006801:Humans; D007501:Iron / Q000502:physiology*; D011233:Precipitin Tests; D013997:Time Factors; D014168:Transferrin / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured
D005290:Ferric Compounds; D014168:Transferrin; C025314:ferric citrate; D006427:Hemin; D007501:Iron; D003676:Deferoxamine