Ss. Lee et al., EFFECTS OF ESTRADIOL AND PROGESTERONE ON CYTOCHROME P4501A1 EXPRESSION IN HEPA 1C1C7 CELLS, Biochemistry and molecular biology international, 45(4), 1998, pp. 775-781
The effects of estradiol and progesterone on the expression of cytochr
ome P4501A1 were investigated in Hepa 1c1c7 cells. Both steroids, at 1
0 mu M concentration, increased P4501A1-mediated 7-ethoxyresorufin O-d
eethyalase activity and amounts of its immunoreactive protein and CYP1
A1 mRNA. Gel shift assay revealed that the steroids could induce both
AhR transformation and binding of the ligand-AhR complex to its specif
ic DNA recognition site. Transient transfection demonstrated that 5'-f
lanking region of CYP1A1 could respond to the steroid action. The comp
etitive binding assay showed that the steroids bound to AhR with moder
ate affinity. These results suggested that steroidal structure can be
AhR ligands and induce CYP1A1 expression in AhR-dependent manner.