Figure 1.

Silenced methylated reporter genes can be reactivated with 5-azacytidine. (Top) β-Galactosidase activity from cells stably transfected with the β-galactosidase gene under the control of an nonmethylated promoter-enhancer. Ponasterone A (10 μM) was added to the cultures and induction of β-galactosidase was tested 48 h later. (Middle) Same cell type stably transfected with a β-galactosidase construct containing the methylated promoter-enhancer. (Bottom) Pretreatment of above cells (silent reporter gene) with 2.5 μM 5-azacytidine for 5 days and then further a treatment with 10 μM ponasterone A for 48 h.