Fig. 2

Overview of extracellular cholesterol uptake pathways utilized in cancer cells. Cells can efficiently take up and utilize extracellular cholesterol mainly by two different mechanisms: a receptor-mediated endocytosis involving LDLR or SR-B1, or by macropinocytosis, a receptor independent internalization mechanism which involves actin filament reorganization under the plasma membrane. Cholesteryl esters that are taken up from the extracellular environment are hydrolysed to cholesterol in lysosomes and transferred to NPC2 and then outside of lysosome through NPC1. All these pathways are often upregulated in cancer