Niemann-Pick C1-Like 1 (NPC1L1) is a protein found on the gastrointestinal tractepithelial cells[5] as well as in hepatocytes.[6] Specifically, it appears to bind to a critical mediator of cholesterol absorption.
The drug ezetimibe inhibits NPC1L1 causing a reduction in cholesterol absorption, resulting in a blood cholesterol reduction of between 15-20%.[7] Polymorphic variations in NPC1L1 gene could be associated with non-response to ezetimibe treatment.[8]
NPC1L1 has been shown to be an accessory receptor for hepatitis C virus entry into cells, and thus ezetimibe might be used as a therapeutic strategy.[9]
As cancer appeared more frequently in patients treated with simvastatin-ezetimibe combination therapy in one clinical trial,[10] it had been hypothesized that NPC1L1 by ezetimibe might be associated with an increase cancer risk.[11] However a meta-analysis of ezetimibe clinical data showed no increased risk of cancer from treatment with ezetimibe.[12]
^Rossebø AB, Pedersen TR, Boman K, Brudi P, Chambers JB, Egstrup K, et al. (SEAS Investigators) (September 2008). "Intensive lipid lowering with simvastatin and ezetimibe in aortic stenosis". The New England Journal of Medicine. 359 (13): 1343–56. doi:10.1056/NEJMoa0804602. PMID18765433.
^Peto R, Emberson J, Landray M, Baigent C, Collins R, Clare R, Califf R (September 2008). "Analyses of cancer data from three ezetimibe trials". The New England Journal of Medicine. 359 (13): 1357–66. doi:10.1056/NEJMsa0806603. PMID18765432.
^Savarese G, De Ferrari GM, Rosano GM, Perrone-Filardi P (December 2015). "Safety and efficacy of ezetimibe: A meta-analysis". International Journal of Cardiology. 201: 247–52. doi:10.1016/j.ijcard.2015.08.103. PMID26301648.
Overview of all the structural information available in the PDB for UniProt: Q9UHC9 (Human NPC1-like intracellular cholesterol transporter 1) at the PDBe-KB.