N. Guigal et al., Serum induces a transcriptional activation of CYP1A1 gene in HepG2 independently of the AhR pathway, LIFE SCI, 68(18), 2001, pp. 2141-2150
CYP1A1 is largely implicated in carcinogenesis. To date, it is known that t
his gene is induced by xenobiotics such as polycyclic aromatic hydrocarbons
. In this study, we evaluated the effect of serum in the regulation of CYP1
A1 gene expression. CYP1A1 mRNA level is induced 1) in HepG2 and HT29-D4 ce
lls by 3-methylcholanthrene 2) only in HepG2 after treatment by serum. The
CYP1A1 mRNA induction in HepG2 is the consequence at least in part of a tra
nscriptional activation as was demonstrated by evaluation of the hnRNA leve
l. HepG2 cells were transfected by a plasmid containing the 7.5 Kb of the C
YP1A1 promoter and the CAT reporter gene. No CAT stimulation was observed a
fter serum treatment. These results demonstrated that CYP1A1 is induced at
a transcriptional level by a physiological compound contained in serum inde
pendently of the Ah receptor and the 7.5 Kb promoter region. (C) 2001 Elsev
ier Science Inc. All rights reserved.