Tecogalan sodium, a bacteria-derived sulfated polysaccharide, inhibits in vitro angiogenesis through the regulation of collagenase gene expression by retinal capillary endothelial cells

Purpose. Tecogalan sodium (tecogalan), a bacteria-derived sulfated polysaccharide, has been reported to prevent basic fibroblast growth factor (bFGF) binding to endothelial cells. We examined whether the interference with endothelial cell-extracellular matrx interaction is involved in the anti-angiogenic activity of tecogalan. Method. Proliferative activity of bovine retinal capillary endothelial cells (RECs) was examined by DNA synthesis assay. The lengths of tubular structures formed in type I collagen gels were measured with an image analyzer. The effect of tecogalan on collagenase gene expression by RECs was analysed using northern blot technique. Results. Tecogalan potently inhibited bFGF-induced proliferation and tube-forming activity of RECs. Tube forming activity was significantly suppressed even when RECs were stimulated by vascular endothelial cell growth factor (VEGF) or fetal bovine serum only. Tecogalan prevented endothelial cell adhesion to type I collagen, and it also suppressed the collagenase gene expression induced by type I collagen. Conclusions. In addition to the blockade of bFGF-binding to endothelial cells, down-regulation of collagenase gene expression and the interference with endothelial cell adhesion to the extracullular matrix are suggested as possible mechanisms of the anti-angiogenic activity of tecogalan.