Identification of danthron as an isoform-specific inhibitor of HEME OXYGENASE-1/cytochrome P450 reductase interaction with anti-tumor activity.

Background: Heme oxygenase (HO) catalyzes NADPH-dependent degradation of heme to liberate iron, carbon monoxide and biliverdin. The interaction between HO and cytochrome P450 reductase (CPR), an electron donor, is essential for HO activity. HO-1 is a stress-inducible isoform whereas HO-2 is constitutively expressed.