The biochemical modification of the erythrocyte membranes from women with ovarian cancer.

The aim of our work was quantitative evaluation of the protein and phospholipid fractions of mature erythrocyte membranes separated from women with ovarian cancer. Blood was sampled from 30 women with ovarian cancer, aged 24-79 years, in the third stage of clinical progression of the disease. Phospholipids were separated from membranes by Müller's acidic extraction method and analysed in thin-layer two-dimensional chromatography. On the silica gel plates nine fractions of phospholipids were separated: sphingomyelin (SPH), phosphatidylethanolamine (PE), phosphatidlyserine (PS), phosphatidylcholine (PC), lysophosphatidylcholine (LPC), phosphatidic acid (PA), phosphatidylinositol (Ptd Ins), phosphatidylinositol-4-phosphate (Ptd Ins-4-P), phosphatidylinositol-4,5-diphosphate (Ptd Ins-4,5-P2). The activity of phospholipase C in erythrocyte membranes was determined by Akhrem's spectrophotometric method. Membrane proteins were separated by polyacrylamide gel electrophoresis, SDS-PAGE. It was shown that PS, SPH, LPC and PA fractions were significantly diminished. The concentration of Ptd Ins-4-P and Ptd Ins-4,5-P2 was significantly increased with simultaneous reduction in Ptd Ins level. The inhibition of phospholipase C reached 80%. The quantitative protein evaluation showed a statistically significant decrease in spectrin and a significant increase in 4.1 protein. The quantitative changes, observed in phospholipid and protein fractions, led to the restructuring of the erythrocyte membrane cytoskeleton, which may be connected to increased susceptibility to haemolysis of red blood cells.