The role of oxysterol-binding protein and its related proteins in cancer.

Oxysterol-binding protein (OSBP) and its related proteins (ORPs) constitute a large, evolutionarily conserved family of lipid-binding proteins that are associated with a wide range of cellular activities. The core function of OSBP/ORPs appears to be moving lipids between cellular membranes in a non-vesicular manner. Recent studies have unveiled a novel, counter-transport mechanism of cellular lipid transfer mediated by OSBP/ORPs at the membrane contact sites that involves phosphatidylinositol 4-phosphate. Importantly, the OSBP/ORPs family has also been implicated in cell signalling pathways and cancer development. Here, we summarize recent progress in understanding the role of OSBP/ORPs in cancer development, and discuss how the lipid transfer function of OSBP/ORPs may underpin their role in tumorigenesis.