Cholesterol levels and plasma membrane fluidity in 3T3 and SV101-3T3 cells.
Polyene antibiotics such as filipin selectively inhibit wheat germ agglutinin-induced agglutination of transformed and malignant cells compared to normal cells (Hatten ME, Burger MM: Biochemistry 18: 739, 1979). Since filipin binds specifically to cholesterol, we measured cholesterol levels in 3T3 cells and SV101-3T3 cells. SV101-3T3 cells contained 50-100% more cholesterol per cell than 3T3 cells. Both cell types were starved for cholesterol by growth in lipid-depleted medium plus 25-hydroxycholesterol. The cholesterol level of SV101-3T3 cells decreased by 30-50%, while the level in 3T3 cells remained constant. Filipin-stained SV101-3T3 cells revealed bright patches of filipin under fluorescence microscopy. These patches were absent in 3T3 cells and in SV101-3T3 and 3T3 cells starved for cholesterol. We selectively labeled plasma membranes of these cells with a spin label analog of phosphatidylcholine. The spin label indicated differences in plasma membrane fluidity that may be related to the different cholesterol levels in 3T3 and SV101-3T3 cells.
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000032:analysis; D002472:Cell Transformation, Viral; D002784:Cholesterol / Q000032:analysis*; D005372:Filipin / Q000494:pharmacology; D008560:Membrane Fluidity / Q000187:drug effects; D051379:Mice; D008856:Microscopy, Fluorescence; D010743:Phospholipids / Q000032:analysis; D013539:Simian virus 40
D010743:Phospholipids; D005372:Filipin; D002784:Cholesterol