Phospholipid Content and Composition of Human Meningiomas

The content and distribution of phospholipids, as well as their fatty acid composition, were studied in 16 human meningiomas in comparison with normal leptomeninges. The total phospholipid content of tumors (expressed as organic phosphorus/mg DNA) was similar to that of the tissue from which they originated. The same phospholipid classes were present in both tissues, but with a different pattern: an increase of phosphatidylinositol and phosphatidylcholine and a decrease of sphingomyelin and alkenyl-acyl phosphatidylethanolamine were detected in meningiomas. Stearic, palmitic, and oleic acids were the major phospholipid fatty acids in both leptomeninges and meningiomas. However, remarkable differences between the fatty acid composition of the two tissues were shown. The most striking difference is a marked increase of unsaturated fatty acids in tumors associated with a decrease of saturated forms. This feature is common to all major phospholipid classes. The possible significance and role of phospholipid modifications in the functional properties of meningioma plasma membrane is discussed.