Modulation of the Expression of Multidrug Resistance Proteins by Sulforaphane and Erucin

Abstract

Sulforaphane increases gene expression through binding of the Nrf2 transcription factor to the antioxidant response element (ARE) in the promoter region of target genes. Because SF and ER increased MRP1 expression at the mRNA level, we investigated the impact of these compounds on MRP1 transcription. Non-small cell lung cancer cells (A549) and human liver carcinoma cells (HepG2) were transfected with an MRP1-luciferase reporter gene and treated with SF or ER. Neither SF nor ER increased luciferase activity in the transfected cells. In addition, overexpression of Nrf2 in A549 cells had no effect on MRP1-luc expression. These results indicate that SF and ER increase MPR1 mRNA and protein levels via a non-transcriptional mechanism and that activation of Nrf2 does not induce transcription of the mrp1 gene.