REEXPRESSION OF C EBP-ALPHA INDUCES CYP2B6, CYP2C9 AND CYP2D6 GENES IN HEPG2 CELLS/

Cytochrome P450 (CYP) activity is very low or even absent in human hep atomas, a phenomenon that is accompanied by low levels of some liver t ranscription factors, notably C/EBP alpha. To investigate a possible l ink between this transcription factor and hepatic CYP expression, we h ave stably transfected HepG2 cells with a C/EBP alpha vector containin g a Zn-inducible metallothionein promoter. Expression of functional C/ EBP alpha up to liver levels concomitantly increased the mRNAs of seve ral members of the CYP2 family (2B6, 2C9 and 2D6), suggesting that thi s transcription factor mag play a relevant role in controlling the hep atic expression of CYP enzymes. (C) 1998 Federation of European Bioche mical Societies.