Expression and regulation of breast cancer resistance protein and multidrug resistance associated protein 2 in BALB/c mice

Abstract

Microsomal enzyme inducers are known to influence the expression of many transporter proteins and mRNA. In this study, we examined the effects of microsomal enzyme inducers on the mRNA expression of Breast Cancer Resistance Protein (BCRP) and Multidrug Resistance Associated Protein 2 (MRP2) in BALB/c mice. mRNA expression in liver, duodenum, jejunum and ileum was examined in mice, which were treated with microsomal enzyme inducers-aryl hydrocarbon receptor (AhR) ligands 3-methylcholanthrene (3-MC) and pregnane-x-receptor (PXR) ligand pregenolone-16α-carbonitrile (PCN) and compared with control vehicle. The results suggested that the expression level of bcrp mRNA in the ileum was twice that in the liver, duodenum and jejunum using both semi quantitative PCR and Real-time PCR. Mrp2 mRNA was significantly increased by both PCN and 3-MC treatment. In contrast, bcrp mRNA expression was not significantly affected by these inducers. In summary, this study demonstrated that the expression of mrp2 mRNA is regulated by PCN and 3-MC, however, bcrp mRNA expression was not significantly affected by PCN and 3-MC. © 2006 Pharmaceutical Society of Japan.