Heparan Sulfate Degradation: Relation to Tumor Invasive and Metastatic Properties of Mouse B16 Melanoma Sublines

Abstract

After transport in the blood and implantation in the microcirculation, metastatic tumor cells must invade the vascular endothelium and underlying basal lamina. Mouse B16 melanoma sublines were used to determine the relation between metastatic properties and the ability of the sublines to degrade enzymatically the sulfated glycosaminoglycans present in the extracellular matrix of cultured vascular endothelial cells. Highly invasive and metastatic B16 sublines degraded matrix glycosaminoglycans faster than did sublines of lower metastatic potential. The main products of this matrix degradation were heparan sulfate fragments. Intact B16 cells (or their cell-free homogenates) with a high potential for lung colonization degraded purified heparan sulfate from bovine lung at higher rates than did B16 cells with a poor potential for lung colonization. Analysis of the degradation fragments indicated that B16 cells have a heparan sulfate endoglycosidase. Thus the abilities of B16 melanoma cells to extravasate and successfully colonize the lung may be related to their capacities to degrade heparan sulfate in the walls of pulmonary blood vessels.

Degradation of sulfated proteoglycans in the subendothelial extracellular matrix by human platelet heparitinase.

“…In fact, different substrate specificities were demonstrated for the platelet and B16 melanoma heparan sulfate-degrading enzymes. Whereas the platelet enzyme depolymerizes both heparan sulfate and heparin into small oligosaccharides (1,3), the enzyme from B16 melanoma was found to be very active against heparan sulfate, while heparin was not cleaved at significant rates (25). We have observed that the average Mr of ECM heparan sulfate degradation fragments was of a similar size (8,000-10,000 D) and almost no partially degraded chains, which eluted between peaks I and II, were produced regardless of the cell type and incubation conditions.…”

“…We have observed that the average Mr of ECM heparan sulfate degradation fragments was of a similar size (8,000-10,000 D) and almost no partially degraded chains, which eluted between peaks I and II, were produced regardless of the cell type and incubation conditions. Studies with B16 melanoma cells have demonstrated that heparan sulfate degradation fragments from subendothelial ECM were larger than those of heparan sulfate degradation products from other sources (25). It was suggested that because of its block type structure of low N-acetyl group content (heparin-like structure) (21), ECM We have previously shown that platelet interaction with the ECM is associated with the formation of platelet aggregates (6).…”

Heparanase upregulation by colonic epithelium in inflammatory bowel disease

“…4,5 Traditionally, heparanase activity was well correlated with the metastatic potential of tumor-derived cells, attributed to enhanced cell dissemination as a consequence of HS cleavage and remodeling of the ECM barrier. [6][7][8][9] A proof-of-concept of this notion has recently been established by using a specific antiheparanase ribosyme and siRNA methodology, 10 clearly implicating heparanase activity as a critical requisite for metastatic spread. Similarly, heparanase was implicated in cell dissemination associated with inflammation and autoimmunity.…”

Spatial and temporal heparanase expression in colon mucosa throughout the adenoma-carcinoma sequence

“…1,2 Traditionally, heparanase activity was implicated in cellular invasion associated with angiogenesis, inflammation and cancer metastasis. [10][11][12][13][14] Recently, this notion gained further support by employing siRNA and ribozyme technologies, clearly depicting heparanase-mediated heparan sulfate cleavage and extracellular …”

“…1,2 Traditionally, heparanase activity was implicated in cellular invasion associated with angiogenesis, inflammation and cancer metastasis. [10][11][12][13][14] Recently, this notion gained further support by employing siRNA and ribozyme technologies, clearly depicting heparanase-mediated heparan sulfate cleavage and extracellular matrix remodeling as critical requisites for metastatic spread. 15 Since the cloning of the heparanase gene and the availability of specific molecular probes, heparanase upregulation was documented in an increasing number of primary human tumors.…”