Transcriptional modulation of the NAD(P)H:quinone oxidoreductase 1 by mercury in human hepatoma HepG2 cells

► Hg2+ up-regulates human NQO1 primarily through a transcriptional mechanism. ► Hg2+ may have cytoprotective properties by increasing the expression of NQO1. ► Nrf2 is involved in the regulation of NQO1 by Hg2+. ► We demonstrated that the AhR level is dependent on the expression of Nrf2.