ANTIPROLIFERATIVE, CYTOTOXIC AND RECOVERY EFFECTS IN TUMOR-CELL CULTURES TREATED WITH SYNTHETIC PHOSPHOLIPIDS

Antiproliferative and cytotoxic efficacies of the phospholipids OPP an d HPC were compared in a panel of 10 human and rat tumor cell lines. T he dose ranges were similar for the inhibition of cell growth measured by ID50 and for the cytotoxic effect (LD(50)). The ratios of LD(50)/I D50 revealed variations between the individual cell lines. After initi al inhibition by twice the ID50 complete recovery of proliferation was observed in OPP withdrawal experiments. Cultivation in the continuous presence of OPP resulted in the recovery of proliferation in 3 of 5 c ell lines tested, apparently based on resistant subpopulations.