The mechanism of the bidirectional regulation of the rat alpha-fetoprotein gene by glucocorticoid hormone.
pAFP-CAT, a recombinant plasmid containing 5'-flanking sequence from -7 kb to +7 bp of rat alpha-fetoprotein (AFP) gene can drive the expression of the bacterial chloramphenicol acetyltransferase gene in McA-RH7777 and McA-RH8994 rat hepatoma cell lines. Dexamethasone treatment suppresses pAFP-CAT expression in McA-RH7777 cells but increases its expression in McA-RH8994 cells, which mimics the dexamethasone responses of the endogenous AFP gene in both cell lines. However, dexamethasone treatment enhanced pMMTV-CAT expression in both cell lines. These data suggest that the effects of dexamethasone on AFP gene expression may be mediated by different trans-acting factors binding to the specific cis-elements of the 5'-flanking region of the rat AFP gene.
Dong
J M
JM
Department of Biochemistry, University of Vermont, Burlington 05405.
Nordloh
P W
PW
Chiu
J F
JF
D000818:Animals; D015152:Blotting, Northern; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D003907:Dexamethasone / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D005938:Glucocorticoids / Q000502:physiology*; D010957:Plasmids / Q000235:genetics; D051381:Rats; D014162:Transfection / Q000235:genetics; D014407:Tumor Cells, Cultured; D000509:alpha-Fetoproteins / Q000235:genetics*
D005938:Glucocorticoids; D000509:alpha-Fetoproteins; D003907:Dexamethasone; D015500:Chloramphenicol O-Acetyltransferase