In Vitro Effects of Glycosphingolipids on Human Tumor Cell Proliferation 1

Abstract

A drug-resistant subpopulation of cells (HTFU) was previously isolated from the human colonic carcinoma cell line HT29. The cell lines varied significantly in in vitro growth patterns with HTFU cells showing contact inhibition while HT29 cells demonstrated uncontrolled growth (10). The malignant cell lines were grown in the presence of various concentrations of blood group A fucolipid, Lewis_b, Forssman hapten, and ceramide tri-hexoside for 2 weeks. Although HTFU cells demonstrated an equal or enhanced sensitivity to the lipids relative to HT29 cells, the cell lines responded in similar fashion to each lipid. Treatment with Forssman and ceramide trihexoside induced a temporary inhibition of cell proliferation, however, continued exposure to these lipids became stimulatory. Exposure to Lewis_b and blood group A fucolipids caused a permanent retardation of cell proliferation.