ELEVATED LEVELS AND ALTERED FATTY-ACID COMPOSITION OF PLASMA LYSOPHOSPHATIDYLCHOLINE (LYSOPC) IN OVARIAN-CANCER PATIENTS

Lysophosphatidylcholine (lysoPC), a product of phosphatidylcholine (PC ) hydrolysis via phospholipase A activity, has been proposed to activa te cells from a number of lineages. Here, we demonstrate that lysoPC l evels are significantly elevated (by 43% overall, relative to normal c ontrols) in the plasma of ovarian cancer patients. This does not appea r to be common to all cancers as 5 out of 6 leukemia patients tested h ad markedly lower (less than one-half of normal) plasma lysoPC. In the plasma of ovarian cancer patients, the percentages of palmitoyl- and stearoyl-lysoPC species were significantly higher, whereas oleoyl and particularly linoleoyl-lysoPC were significantly lower than in control subjects. The molar ratios of lysoPC/PC and palmitoyl-lysoPC/linoleoy l-lysoPC were also significantly elevated in the plasma of ovarian can cer patients compared with those of control subjects. Furthermore, the calculated value of plasma (lysoPC/PC) x (palmitoyl-lysoPC/linoleoyl- lysoPC) was markedly higher in patients compared with controls. (C) 19 97 Wiley-Liss, Inc.