Heparan Sulfate Proteoglycans Play a Dual Role in Regulating Fibroblast Growth Factor-2 Mitogenic Activity in Human Breast Cancer Cells

Stimulation of DNA Synthesis and Cell Proliferation of Human Mammary Myoepithelial-like Cells by Hepatocyte Growth Factor/Scatter Factor Depends on Heparan Sulfate Proteoglycans and Sustained Phosphorylation of Mitogen-activated Protein Kinases p42/44

“…5A). As reported in other systems (25,31,32), no change in cell morphology or cell death (assessed by exclusion of Trypan Blue and cell numbers using a hemocytometer) was detected (data not shown). In controls, HGF/SF still failed to stimulate DNA synthesis in chlorate-treated Huma 109 cells plated on plastic (Fig.…”

“…After 4 h, the wells were rinsed twice with PBS before seeding the cells. Sulfated glycosaminoglycan-deficient Huma 109 cells were prepared as described previously (5,9,25). Cells were incubated for 4 h in sulfate-free Dulbecco's modified Eagle's medium supplemented with 10% dialyzed fetal calf serum (v/v) and 15 mM NaClO 3 .…”

“…Following trypsinization, the cells were seeded in 24-well plates or 10-cm dishes as described for DNA synthesis or Western blot analysis, respectively, except that sulfate-free Dulbecco's modified Eagle's medium supplemented with 15 mM NaClO 3 was used throughout. As others have described, cells can be kept viable in sulfate-free medium containing chlorate for up to 1 month (25,31,32). Checks were always made on cell death and protein synthesis.…”

“…Chlorate is a potent inhibitor of sulfation (31-33) widely used to address HS function (5,9,25,34,35). Following this treatment, cells were quiescent, and the level of [ 3 H]thymidine incorporation into cellular DNA was always very low, probably because of the greater cell synchrony obtained with this treatment (Fig.…”

Transforming growth factor beta 1 and sodium butyrate differentially modulate urokinase plasminogen activator and plasminogen activator inhibitor-1 in human breast normal and cancer cells

“…Another possibility is that the action of growth factors, such as TGF-P, hepatocyte growth factor (HGF) and fibroblast growth factor (FGF), requires the activation and/or release of these factors from extracellular matrix, which may be degraded by uPA. As normal cells produce more growth factor-binding extracellular Figure 4 matrix molecules, such as heparan sulphate proteoglycans than tumoral cells (Delehedde et al, 1996; unpublished results), it is possible that normal cells need more proteolytic activity to degrade the growth factor binding extracellular matrix to maintain cell growth, particularly in serum-free culture conditions. We have shown that in the human breast cancer cell line MDA-MB-231, TGF-,B1 strongly increased cell-associated and secreted uPA activity.…”