Phospholipid metabolism and resistance to glucocorticoid-induced apoptosis in a human leukemic cell line:: a 31P-NMR study using a phosphonium analog of choline

In order to evaluate any connection between phospholipid metabolism and the dexamethasone resistance in CEM-C1-15 leukemic cells, a phosphonium analog of choline was used to study the phospholipid metabolism in dexamethasone-sensitive and dexamethasone-resistant leukemic cells using P-31-NMR spectroscopy. Measurements were done on the two cell lines in the presence and absence of dexamethasone, a synthetic glucocorticoid steroid. Dexamethasone was found to cause a significant reduction in the phospholipid metabolism of the dexamethasone-sensitive CEM-C7-14 cells. In contrast, dexamethasone caused a significant enhancement of the phospholipid metabolism in the dexamethasone-resistant CEM-C1-15 cells, indicating a significant difference between the two cell lines in phospholipid metabolism during apoptosis. The results of this study suggest the involvement of phospholipid metabolism in the mechanism of dexamethasone resistance in the CEM-C1-15 cells. (C) 1999 Published by Elsevier Science Ireland Ltd. All rights reserved.