The relationship between cellular ether glycerophospholipid content and sensitivity of cancer cells to 1-O-octadecyl-2-O-methyl-glycerophosphocholine.

Cancer cells are more susceptible to the growth-inhibitory effects of alkyl lysophospholipids than normal cells, but the mechanism of this selectivity is unknown. In this study we have investigated the hypothesis that the sensitivity of cells to alkyl lysophospholipids is related to the cellular ether lipid content. The order of decreasing sensitivity of the cells to the growth-inhibitory effect of 1-O-octadecyl-2-O-methyl-glycerophosphocholine (ET-18-OCH3) was MCF 7 > T84 > Malme 3M > A427 > A549, while the order of decreasing ether phospholipid content as a proportion of the total phospholipid was T84 > A427 = A549 = Malme 3M > MCF7. There was also no correlation between ET-18-OCH3-sensitivity and the proportion of ether lipid in the cholineglycerophospholipid or ethanolamineglycerophospholipid classes. Our results clearly indicate that the postulated relationship between ether phospholipid content and ET-18-OCH3-susceptibility may have very limited applicability and is unlikely to be the underlying reason for the selective effects of alkyl lysophospholipids.