[Effect of hypoxia on expression of multidrug resistance protein 2 and its regulation mechanism].

Drug efflux transporters plays a key role in pharmacokinetics parameters changes. In recent years, in addition to P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), MRP2 has become an advanced research hotspot. Several signaling pathways andtranscription factors have been reported to be involved in regulation of MRP2 expression in hypoxic microenvironment of tumor, such as peroxisome proliferators-activated receptors (PPARα), nuclear factor κB (NF-κB), pregnane X receptor (PXR), farnesoid X receptor (FXR), constitutive androstane receptor (CAR) and microRNA. But it is not fully understood how MRP2 is regulated under hypoxia. MRP2 is one of the most important efflux transporter proteins. Many drugs or inhibitors have been shown to be its substrate. In the hypoxic environment, changes in expression of MRP2 can significantly affect drug's pharmacokinetics (absorption, distribution, metabolism, excretion). Simultaneously, the regulation of MRP2 expression under hypoxic might involve several signal pathways and many genes, which constitute an integral gene regulatory networks.