Tumor cell lipid composition and sensitivity to humoral immune killing. II. Influence of plasma membrane and intracellular lipid and fatty acid content
Schlager, S.I.; Ohanian, S.H.
Journal of Immunology 125(2): 508-517
1980
ISSN/ISBN: 0022-1767 PMID: 7391566 Document Number: 167833
Metabolic inhibitors (e.g., adriamycin) and hormones (e.g., insulin and hydrocortisone) enhance and decrease, respectively, the sensitivity of line-10 guinea pig hepatoma cells to antibody-complement killing; these effects were correlated with drug- and hormone-induced changes in cellular lipid and fatty acid composition. Analysis of the lipid and fatty acid content of subcellular fractions from drug- and hormone-treated cells showed that the changes in lipid composition observed in whole cell lipid extracts were a reflection of changes occurring in the plasma membrane and in intracellular membranes (i.e., mitochondria, nuclear membrane, endoplasmic reticulum, microsome). Adriamycin treatment decreased the unesterified cholesterol and saturated triglyceride content while increasing the polyunsaturated fatty acid-containing triglycerides and phospholipids in the plasma and intracellular membranes; 5-fluorouracil (a drug that is not effective in increasing the sensitivity of the cells to antibody-C killing) did not have these effects. Treatment of the cells with insulin or hydrocortisone had exactly the opposite effects of those observed in the adriamycin-treated cells. Modifications in the chemical composition of intracellular membranes and the plasma membrane of nucleated cells may influence certain physical properties of the cell membranes (e.g., fluidity, permeability) and as a result could affect the outcome of humoral immune attack at the cell surface.