title: Resveratrol inhibits genistein-induced multi-drug resistance protein 2 (MRP2) expression in HepG2 cells.
abstract: The interactions between various dietary cancer chemopreventive phytochemicals in drug transporter functions are not well studied. In this study, the effects of genistein and resveratrol on the multidrug resistance protein 2 (MRP2) expression and the underlying molecular mechanisms were investigated using HepG2-C3 cells that are stably transfected with a construct containing human MRP2 promoter region conjugated with luciferase reporter gene. A 3-fold induction of MRP2 luciferase activity was observed after genistein (50μM) treatment to HepG2-C3 cells, but was diminished by the resveratrol (50μM) cotreatment. This observation was further validated by Western blot analysis and RT-PCR analysis as resveratrol also inhibited genistein-induced MRP2 protein synthesis and mRNA expression. Immunofluorescence study revealed that genistein-induced formation of MRP2 vacuoles was dramatically reduced by resveratrol. The binding affinity between retinoid X receptor alpha (RXRα) and MRP2 promoter was examined by DNA-protein pull-down assay. The results showed that resveratrol inhibited the genistein-induced binding of RXRα to the promoter sequence of MRP2 gene, and this mechanism could potentially contribute to the inhibition of genistein-induced MRP2 expression by resveratrol. Taken together, our present study suggests that naturally occurring phytochemicals can potentially interfere with each other's regulatory function on the cancer chemoprevention-related genes through a competitive mechanism.
authors.affiliation: Graduate Program in Pharmaceutical Science, Ernest-Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, United States.
authors.forename: Jung-Hwan
authors.initials: JH
authors.lastname: Kim
authors.forename: Chi
authors.initials: C
authors.lastname: Chen
authors.forename: Ah-Ng
authors.initials: AN
authors.lastname: Tony Kong
mesh_terms: D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004347:Drug Interactions; D015870:Gene Expression / Q000187:drug effects; D017930:Genes, Reporter; D019833:Genistein / Q000494:pharmacology* / Q000633:toxicity; D056945:Hep G2 Cells; D006801:Humans; D008156:Luciferases / Q000235:genetics; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000096:biosynthesis* / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D000077185:Resveratrol; D047490:Retinoid X Receptor alpha / Q000235:genetics; D013267:Stilbenes / Q000494:pharmacology* / Q000633:toxicity; D014617:Vacuoles / Q000378:metabolism
chemical_list: D017931:DNA Primers; D019833:Genistein; D008156:Luciferases; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D012333:RNA, Messenger; D000077185:Resveratrol; D047490:Retinoid X Receptor alpha; D013267:Stilbenes; C000715087:ABCC2 protein, human