Thyroid hormone effect on alpha-fetoprotein and albumin coordinate expression by a human hepatoma cell line.
The action of triiodothyronine on the production of alpha-fetoprotein and albumin in serum-free cultures of Hep G2 human hepatoma cells was examined. Our data showed that a marked inhibition (up to 8-fold) of alpha-fetoprotein secretion and an increase in albumin (up to 4-fold) are produced by 10(-8) M triiodothyronine. These effects were slow in their onset and for completion required 20-25 days of treatment with the hormone. However, an exposure of the cells to triiodothyronine for only the first 4 h was sufficient to affect, in a similar way, the secretion of alpha-fetoprotein and albumin when measured 15 days after treatment. The secretion of the two proteins parallels their intracellular levels. The decrease in alpha-fetoprotein production can be explained by a reduction of the RNA coding for the protein. The same is essentially true also for albumin increased secretion and related mRNA expression.
Conti
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R
Cell Biology Laboratory, Sclavo Research Center, Siena, Italy.
Ceccarini
C
C
Tecce
M F
MF
D000418:Albumins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D015152:Blotting, Northern; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005786:Gene Expression Regulation; D006801:Humans; D008113:Liver Neoplasms; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014284:Triiodothyronine / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000378:metabolism; D000509:alpha-Fetoproteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism
D000418:Albumins; D012333:RNA, Messenger; D000509:alpha-Fetoproteins; D014284:Triiodothyronine