Retinoic acid mediates down-regulation of the α-fetoprotein gene through decreased expression of hepatocyte nuclear factors

Thomas R. Magee, Yan Cai, Motawa E. El-Houseini, Joseph Locker, Yu-Jui Yvonne Wan

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

α-Fetoprotein (AFP), a protein highly induced during fetal liver development, is down-regulated by retinoids in the human hepatoma cell line Hep3B, in contrast to up-regulation observed in other cell types. Previously, we have documented that such up-regulation involves direct effects through cis-retinoid X receptor-binding sites in the AFP enhancer. In this report, we show a distinctive effect of all-trans-retinoic acid (RA) in Hep3B cells. RA caused a marked decrease in AFP transcripts. Deletion analysis of the upstream regulatory region of the AFP gene revealed that cis-acting sites required for down-regulation resided near the promoter. Gel mobility shift assays for factors binding to key elements in the AFP promoter region demonstrated that hepatocyte nuclear factor (HNF) 1 binding was diminished in nuclear extracts from RA-treated cells. In addition, HNF4, which is not known to bind to the AFP promoter but does regulate HNF1, was also diminished. The levels of HNF1 and HNF4 mRNA were also decreased following RA treatment. AFP promoter-chloramphenicol acetyltransferase transient transfection assays demonstrated that the level of HNF1 had a direct impact on basal transcription as well as RA-mediated down-regulation of the AFP gene, and that co-transfection of HNF1 and HNF4, but not transfection of either factor alone, reversed the RA-mediated inhibition. Taken together these data point to an interaction among the RA, HNF1, and HNF4 signals, which is reflected in decreased expression of AFP.

Original languageEnglish (US)
Pages (from-to)30024-30032
Number of pages9
JournalJournal of Biological Chemistry
Volume273
Issue number45
DOIs
StatePublished - Nov 6 1998

Fingerprint

Hepatocyte Nuclear Factors
Fetal Proteins
Tretinoin
Down-Regulation
Genes
Transfection
Assays
Hepatocyte Nuclear Factor 1
Up-Regulation
Cells
Retinoid X Receptors
Chloramphenicol O-Acetyltransferase
Nucleic Acid Regulatory Sequences
Retinoids
Electrophoretic Mobility Shift Assay
Transcription
Fetal Development
Genetic Promoter Regions
Liver
Hepatocellular Carcinoma

ASJC Scopus subject areas

  • Biochemistry

Cite this

Retinoic acid mediates down-regulation of the α-fetoprotein gene through decreased expression of hepatocyte nuclear factors. / Magee, Thomas R.; Cai, Yan; El-Houseini, Motawa E.; Locker, Joseph; Wan, Yu-Jui Yvonne.

In: Journal of Biological Chemistry, Vol. 273, No. 45, 06.11.1998, p. 30024-30032.

Research output: Contribution to journalArticle

Magee, Thomas R. ; Cai, Yan ; El-Houseini, Motawa E. ; Locker, Joseph ; Wan, Yu-Jui Yvonne. / Retinoic acid mediates down-regulation of the α-fetoprotein gene through decreased expression of hepatocyte nuclear factors. In: Journal of Biological Chemistry. 1998 ; Vol. 273, No. 45. pp. 30024-30032.
@article{fddd215d939a487fb82f0ce862176f9e,
title = "Retinoic acid mediates down-regulation of the α-fetoprotein gene through decreased expression of hepatocyte nuclear factors",
abstract = "α-Fetoprotein (AFP), a protein highly induced during fetal liver development, is down-regulated by retinoids in the human hepatoma cell line Hep3B, in contrast to up-regulation observed in other cell types. Previously, we have documented that such up-regulation involves direct effects through cis-retinoid X receptor-binding sites in the AFP enhancer. In this report, we show a distinctive effect of all-trans-retinoic acid (RA) in Hep3B cells. RA caused a marked decrease in AFP transcripts. Deletion analysis of the upstream regulatory region of the AFP gene revealed that cis-acting sites required for down-regulation resided near the promoter. Gel mobility shift assays for factors binding to key elements in the AFP promoter region demonstrated that hepatocyte nuclear factor (HNF) 1 binding was diminished in nuclear extracts from RA-treated cells. In addition, HNF4, which is not known to bind to the AFP promoter but does regulate HNF1, was also diminished. The levels of HNF1 and HNF4 mRNA were also decreased following RA treatment. AFP promoter-chloramphenicol acetyltransferase transient transfection assays demonstrated that the level of HNF1 had a direct impact on basal transcription as well as RA-mediated down-regulation of the AFP gene, and that co-transfection of HNF1 and HNF4, but not transfection of either factor alone, reversed the RA-mediated inhibition. Taken together these data point to an interaction among the RA, HNF1, and HNF4 signals, which is reflected in decreased expression of AFP.",
author = "Magee, {Thomas R.} and Yan Cai and El-Houseini, {Motawa E.} and Joseph Locker and Wan, {Yu-Jui Yvonne}",
year = "1998",
month = "11",
day = "6",
doi = "10.1074/jbc.273.45.30024",
language = "English (US)",
volume = "273",
pages = "30024--30032",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "45",

}

TY - JOUR

T1 - Retinoic acid mediates down-regulation of the α-fetoprotein gene through decreased expression of hepatocyte nuclear factors

AU - Magee, Thomas R.

AU - Cai, Yan

AU - El-Houseini, Motawa E.

AU - Locker, Joseph

AU - Wan, Yu-Jui Yvonne

PY - 1998/11/6

Y1 - 1998/11/6

N2 - α-Fetoprotein (AFP), a protein highly induced during fetal liver development, is down-regulated by retinoids in the human hepatoma cell line Hep3B, in contrast to up-regulation observed in other cell types. Previously, we have documented that such up-regulation involves direct effects through cis-retinoid X receptor-binding sites in the AFP enhancer. In this report, we show a distinctive effect of all-trans-retinoic acid (RA) in Hep3B cells. RA caused a marked decrease in AFP transcripts. Deletion analysis of the upstream regulatory region of the AFP gene revealed that cis-acting sites required for down-regulation resided near the promoter. Gel mobility shift assays for factors binding to key elements in the AFP promoter region demonstrated that hepatocyte nuclear factor (HNF) 1 binding was diminished in nuclear extracts from RA-treated cells. In addition, HNF4, which is not known to bind to the AFP promoter but does regulate HNF1, was also diminished. The levels of HNF1 and HNF4 mRNA were also decreased following RA treatment. AFP promoter-chloramphenicol acetyltransferase transient transfection assays demonstrated that the level of HNF1 had a direct impact on basal transcription as well as RA-mediated down-regulation of the AFP gene, and that co-transfection of HNF1 and HNF4, but not transfection of either factor alone, reversed the RA-mediated inhibition. Taken together these data point to an interaction among the RA, HNF1, and HNF4 signals, which is reflected in decreased expression of AFP.

AB - α-Fetoprotein (AFP), a protein highly induced during fetal liver development, is down-regulated by retinoids in the human hepatoma cell line Hep3B, in contrast to up-regulation observed in other cell types. Previously, we have documented that such up-regulation involves direct effects through cis-retinoid X receptor-binding sites in the AFP enhancer. In this report, we show a distinctive effect of all-trans-retinoic acid (RA) in Hep3B cells. RA caused a marked decrease in AFP transcripts. Deletion analysis of the upstream regulatory region of the AFP gene revealed that cis-acting sites required for down-regulation resided near the promoter. Gel mobility shift assays for factors binding to key elements in the AFP promoter region demonstrated that hepatocyte nuclear factor (HNF) 1 binding was diminished in nuclear extracts from RA-treated cells. In addition, HNF4, which is not known to bind to the AFP promoter but does regulate HNF1, was also diminished. The levels of HNF1 and HNF4 mRNA were also decreased following RA treatment. AFP promoter-chloramphenicol acetyltransferase transient transfection assays demonstrated that the level of HNF1 had a direct impact on basal transcription as well as RA-mediated down-regulation of the AFP gene, and that co-transfection of HNF1 and HNF4, but not transfection of either factor alone, reversed the RA-mediated inhibition. Taken together these data point to an interaction among the RA, HNF1, and HNF4 signals, which is reflected in decreased expression of AFP.

UR - http://www.scopus.com/inward/record.url?scp=0032491430&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032491430&partnerID=8YFLogxK

U2 - 10.1074/jbc.273.45.30024

DO - 10.1074/jbc.273.45.30024

M3 - Article

VL - 273

SP - 30024

EP - 30032

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 45

ER -