Pregnane X Receptor and Cancer: Context-Specificity is Key.
Pregnane X receptor (PXR) is an adopted orphan nuclear receptor that is activated by a wide-range of endobiotics and xenobiotics, including chemotherapy drugs. PXR plays a major role in the metabolism and clearance of xenobiotics and endobiotics in liver and intestine via induction of drug-metabolizing enzymes and drug-transporting proteins. However, PXR is expressed in several cancer tissues and the accumulating evidence strongly points to the differential role of PXR in cancer growth and progression as well as in chemotherapy outcome. In cancer cells, besides regulating the gene expression of enzymes and proteins involved in drug metabolism and transport, PXR also regulates other genes involved in proliferation, metastasis, apoptosis, anti-apoptosis, inflammation, and oxidative stress. In this review, we focus on the differential role of PXR in a variety of cancers, including prostate, breast, ovarian, endometrial, and colon. We also discuss the future directions to further understand the differential role of PXR in cancer, and conclude with the need to identify novel selective PXR modulators to target PXR in PXR-expressing cancers.
Department of Anatomy, Physiology and Pharmacology, Auburn University, Auburn, AL 36849, USA; Auburn University Research Initiative in Cancer, Auburn University, Auburn, AL 36849, USA.
Satyanarayana R
SR
Pondugula
Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, Hradec Králové 500 05, Czech Republic, European Union.
Petr
P
Pavek
Albert Einstein Cancer Center, Albert Einstein College of Medicine, New York, NY 10461, USA.
Sridhar
S
Mani
MDR; Pregnane X Receptor; cancer; inflammation; nuclear receptor