Niemann-Pick C1-Like 1 (NPC1L1) is a protein found on the
gastrointestinal tract
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans a ...
epithelial
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellu ...
cells
as well as in
hepatocytes.
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%.
Polymorphic variations in NPC1L1 gene could be associated with non-response to ezetimibe treatment.
NPC1L1 has been shown to be an accessory receptor for
hepatitis C virus
The hepatitis C virus (HCV) is a small (55–65 nm in size), enveloped, positive-sense single-stranded RNA virus of the family '' Flaviviridae''. The hepatitis C virus is the cause of hepatitis C and some cancers such as liver cancer (hepatoc ...
entry into cells, and thus
ezetimibe might be used as a therapeutic strategy.
As cancer appeared more frequently in patients treated with
simvastatin-
ezetimibe combination therapy in one clinical trial,
it had been hypothesized that NPC1L1 by ezetimibe might be associated with an increase cancer risk.
However a meta-analysis of ezetimibe clinical data showed no increased risk of cancer from treatment with ezetimibe.
References
External links
*
* {{PDBe-KB2, Q9UHC9, Human NPC1-like intracellular cholesterol transporter 1