Correlation of tumor metastasis with sterol carrier protein and plasma membrane sterol levels.
Squalene and sterol carrier protein (SCP) levels and sterol/phospholipid molar ratios of whole cells and plasma membranes were measured in cultured primary tumor and metastatic cell lines. SCP is abundant in all cell lines. However, metastatic lines have significantly lower SCP levels and plasma membrane sterol/phospholipid ratios than do primary lines. The results indicate that extremely malignant, metastatic cells are unable to produce or maintain adequate levels of both SCP and plasma membrane sterols when grown in lipoprotein deficient media. This defect, in vivo, probably causes excess uptake of SCP and lipid.
D000818:Animals; D002352:Carrier Proteins / Q000032:analysis*; D002462:Cell Membrane / Q000032:analysis; D003897:Desmosterol / Q000032:analysis*; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D007739:L Cells / Q000032:analysis; D008175:Lung Neoplasms / Q000032:analysis / Q000556:secondary; D008545:Melanoma / Q000032:analysis; D008563:Membrane Lipids / Q000032:analysis*; D051379:Mice; D008815:Mice, Inbred Strains; D008819:Mice, Nude; D009362:Neoplasm Metastasis / Q000503:physiopathology*; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D013185:Squalene / Q000032:analysis*
D002352:Carrier Proteins; C082667:Fabp5 protein, mouse; C086936:Fabp7 protein, mouse; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D008563:Membrane Lipids; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D003897:Desmosterol; D013185:Squalene