Abstract: The overexpression of P-glycoprotein (P-gp) and its coding gene mdr1 is regarded as the classic mechanism of multidrug resistance (MDR). Recent studies find that pregnane X receptor (PXR) can mediate the expression of P-gp. It is confirmed that PXR can also inhibit apoptosis of tumor cells. Therefore, preventing the activation of PXR specifically may be a new method to prevent MDR. 

Key words: Drug resistance, neoplasm, P-glycoprotein, Pregnane X receptor