INHIBITION BY ALKYL-LYSOPHOSPHOLIPIDS OF TRITIATED-THYMIDINE UPTAKE IN CELLS OF HUMAN-MALIGNANT UROLOGIC TUMORS

Abstract

Alkyl-lysophospholipids (ALP) inhibited the uptake of [3H]thymidine by cells from a variety of human urologic tumors in vitro. Cells of prostate carcinomas, a seminoma, various bladder carcinomas and teratocarcinomas showed proliferation rates that were 10% of those of the controls when incubated with some ALP for longer than 24 h. Concentrations as low as 1 .mu.g ALP/ml medium (106 tumor cells) were effective. Antitumor action increased after incubation for 2-5 days. Morphologic studies showed tumor cell death after incubation periods of this length. Equivalent concentrations of conventional cytostatic drugs used in anticancer chemotherapy protocols did not cause greater inhibition of [3H]thymidine uptake by tumor cells in vitro. Human embryonic fibroblasts were not sensitive to ALP; cytostatic drugs completely inhibited their proliferation at comparable doses.