Delehedde M, Deudon E, Boilly B, Hondermarck H
Unité de Dynamique des Cellules Embryonnaires et Cancéreuses, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq Cedex, 59655, France.
Exp Cell Res. 1996 Dec 15;229(2):398-406. doi: 10.1006/excr.1996.0385.
The human breast cancer cell lines MCF-7 and MDA-MB-231 differ in their responsiveness to fibroblast growth factor-2 (FGF-2). This growth factor stimulates proliferation in well-differentiated MCF-7 cells, whereas the less well-differentiated MDA-MB-231 cells are insensitive to this molecule. To investigate the potential regulation of FGF-2 mitogenic activity by heparan sulfate proteoglycans (HSPG), we have treated human breast cancer cells by glycosaminoglycan degrading enzymes or a metabolic inhibitor of proteoglycan sulfation: sodium chlorate. The interaction between FGF-2 and proteoglycans was assayed by examining the binding of 125I-FGF-2 to breast cancer cell cultures as well as to cationic membranes loaded with HSPG. Using MCF-7 cells, we showed that heparinase treatment inhibited FGF-2 binding to HSPG and completely abolished FGF-2 induced growth; chlorate treatment of MCF-7 cells decreased FGF-2 binding to HSPG and cell responsiveness in a dose-dependent manner. This demonstrates a requirement of adequately sulfated HSPG for FGF-2 growth-promoting activity on MCF-7 cells. In highly invasive MDA-MB-231 cells which produce twice as much HSPG as MCF-7 cells and which are not normally responsive to exogenously added FGF-2, chlorate treatment decreased FGF-2 binding to HSPG and induced FGF-2 mitogenic effect. This chlorate effect was dose dependent and observed at concentrations of 10-30 mM; higher chlorate concentrations completely abolished the FGF-2 effect. This shows that the HSPG level of sulfation can also negatively regulate the biological activity of FGF-2. Taken together, these results demonstrate a crucial role for HSPG in both positive and negative control of FGF-2 mitogenic activity in breast cancer cell proliferation.
人乳腺癌细胞系MCF-7和MDA-MB-231对成纤维细胞生长因子2（FGF-2）的反应性不同。这种生长因子刺激分化良好的MCF-7细胞增殖，而分化较差的MDA-MB-231细胞对该分子不敏感。为了研究硫酸乙酰肝素蛋白聚糖（HSPG）对FGF-2促有丝分裂活性潜在的调节作用，我们用糖胺聚糖降解酶或蛋白聚糖硫酸化代谢抑制剂：氯酸钠处理人乳腺癌细胞。通过检测125I-FGF-2与乳腺癌细胞培养物以及负载有HSPG的阳离子膜的结合，来测定FGF-2与蛋白聚糖之间的相互作用。使用MCF-7细胞，我们发现肝素酶处理抑制FGF-2与HSPG的结合并完全消除FGF-2诱导的生长；氯酸钠处理MCF-7细胞以剂量依赖的方式降低FGF-2与HSPG的结合以及细胞反应性作用。这表明硫酸化程度适当HSPG对于FGF-2在MCF-7细胞上的促生长活性是必需的。在高侵袭性MDA-MB-231细胞中，其产生的HSPG是MCF -7细胞的两倍，并且通常对外源添加的FGF-2不敏感，但氯酸钠处理降低了FGF-2与HSPG 的结合并诱导了FGF-2的促有丝分裂作用。这种氯酸钠效应是剂量依赖性的，在10 - 30 mM的浓度下可观察到；更高的氯酸钠浓度完全消除了FGF-2的作用。这表明HSPG的硫酸化水平也可以负向调节FGF-2的生物学活性。综上所述，这些结果表明HSPG在乳腺癌细胞增殖中对FGF-2促有丝分裂活性的正负调控中都起着关键作用。
