Journal of Lipid Research, Vol. 15, 423-431, July 1974
Copyright © 1974 by Lipid Research, Inc.
Phospholipids and acyl groups of subcellular membrane fractions from human intracranial tumors
G. Y. Sun and B. S. Leung
Laboratory of Neurochemistry, Ohio Mental Health and Mental Retardation Research Center, Cleveland, Ohio 44109, and Department of Surgery, University of Oregon Medical School, Portland, Oregon 97201
The phospholipids from subcellular fractions of human intracranial tumors were examined. For comparison, microsomes were isolated from a fetal human brain and from the gray matter of adult human brains. The subcellular membranes of tumors had a higher protein-to-phospholipid ratio than the normal brain membranes. The microsomes from tumors had a lower proportion of diacylglycerophosphorylethanolamine and higher proportions of alkenylacylglycerophosphorylcholine and sphingomyelin (plus diacylglycerophosphorylinositol) than microsomes from the gray matter. Also, the ratios of alkenylacylglycerophosphorylethanolamine to diacylglycerophosphorylethanolamine were higher in the tumors than in the normal controls. The acyl groups of ethanolamine phosphoglycerides in tumor microsomes had relatively more 18:1, 18:2, and 20:4(n - 6) and less 18:0, 22:4(n - 6), and 22:6(n - 3) than the adult brain gray matter. Except for the increase in 18:2, acyl group changes in choline phosphoglycerides between tumors and controls were not as extensive as in the ethanolamine phosphoglycerides. The characteristic features of phospholipids and their constituent acyl groups of tumors were often present in all the subcellular fractions. Although the acyl group profiles of the tumor phosphoglycerides were in closer resemblance to the fetal brain than to the adult brain, other differences were observed. Results indicate that neoplastic brain cells are unique in their cellular composition, and consequently they deviate from the normal neurons and glials in metabolism and functions.
Supplementary key words microsomes fetal brain gray matter
Submitted on October 15, 1973
Accepted on April 11, 1974