The thyroid hormone down-regulates the mouse alpha-foetoprotein promoter.
The thyroid hormone (T3) was shown to down regulate the level of alpha-foetoprotein (AFP) mRNA in hepatoma cells HepG2. Recombinant plasmids containing segments from the mouse AFP gene promoter were transfected in HepG2 cells and transient expression assays showed that the T3 inhibitory effect depends on the sequence limited by positions -80 and -38, upstream from the TATA box. This sequence is able to confer T3 sensitivity to a heterologous promoter and contains a putative T3-responsive element, as well as likely CEBP- and HNF1-responsive elements. These observations suggest that T3 is a good candidate for hormonal control of the AFP gene expression and especially for the neonatal shut off of the gene.
Caturla
M
M
Université Libre de Bruxelles, Département de Biologie Moléculaire, Rhode-St-Genése, Belgium.
Van Reeth
T
T
Drèze
P
P
Szpirer
J
J
Szpirer
C
C
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002455:Cell Division / Q000187:drug effects; D004274:DNA, Recombinant / Q000187:drug effects / Q000235:genetics; D004742:Enhancer Elements, Genetic / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D006801:Humans; D051379:Mice; D009841:Oligonucleotides / Q000235:genetics; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D013963:Thyroid Hormones / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects / Q000235:genetics; D014407:Tumor Cells, Cultured; D000509:alpha-Fetoproteins / Q000187:drug effects / Q000235:genetics*
D004274:DNA, Recombinant; D009841:Oligonucleotides; D012333:RNA, Messenger; D013963:Thyroid Hormones; D000509:alpha-Fetoproteins