Antiproliferative activity of ceramides isolated from normal human ovary and ovarian tumor.

Ceramides modulate cell growth, differentiation and apoptosis. We have previously demonstrated that human epithelial ovarian tumors contain dihydroceramides that are absent from normal ovary. Dihydroceramides differ in their biological effects from ceramides; therefore antiproliferative activity of ceramides isolated from normal human ovary and ovarian tumors was studied. Ceramides (3 microM) of normal ovary are more potent inhibitors of [3H]thymidine incorporation into human ovarian carcinoma cells (CaOv) than ceramides of ovarian tumors. Effects of various pools of tumor ceramides were similar regardless of significant differences in the contents of sphingenine and sphinganine. It is suggested that antiproliferative activity of ceramides depends not only on the sphingoid base structure but also on the fatty acid structure.