Effect of heparin on cell proliferation: lack of correlation with heparin binding sites on cell membrane

In this study an attempt was made to correlate the in-vitro anti-proliferative effect of heparin with the heparin binding on the cell surface. Cells with different sensitivities to the anti-proliferative effect of heparin (BHK-21, FAO, SMC, BAEC, A-431, V-79, and skin fibroblasts) were incubated with [3H]heparin either in the presence or in the absence of unlabelled heparin. A saturable binding was found only in BHK-21, FAO, SMC, BAEC and V-79. Scatchard analysis revealed the presence of a single class of binding sites. The binding of [3H] heparin was efficiently displaced by unlabelled heparin, pentosan polysulfate and low-molecular-weight heparin, but not by dermatan sulfate. Although the sensitivity to the anti-proliferative effect of heparin varied considerably among the cell types (BHK-21 > SMC, FAO > BAEC > V-79), there was no correlation between the reduction of proliferation of these cells and either their heparin binding capacity or the number of binding sites per cell.