Doerr M E, Jones J I
Department of Medicine, University of North Carolina, Chapel Hill 27599-7170, USA.
J Biol Chem. 1996 Feb 2;271(5):2443-7. doi: 10.1074/jbc.271.5.2443.
The effects of insulin-like growth factor I (IGF-I) on the migration of two human breast cancer cell lines, MCF-7 and MDA-231, were examined using a modified Boyden chamber. 10 ng/ml was the optimal IGF-I concentration for stimulation of migration. The majority of IGF-I-stimulated migration in both cell types was due to chemotaxis. MCF-7 cells failed to migrate on membranes coated with gelatin or fibronectin and migrated only in small numbers on laminin. In contrast, when vitronectin- or type IV collagen-coated membranes were used, the MCF-7 cells migrated in large numbers specifically in response to IGF-I but not to 10% fetal calf serum, epidermal growth factor, fibroblast growth factor, or platelet derived growth factor-BB. An IGF-I receptor-blocking antibody inhibited IGF-I-stimulated migration in both cell types. In addition, a blocking antibody to the alpha v beta 5 integrin (a vitronectin receptor) inhibited migration of MCF-7 cells in response to IGF-I through vitronectin but not through type IV collagen. Similarly, blocking antibodies specific for alpha 2 and beta 1 integrins significantly inhibited migration of both cell types through type IV collagen-coated membranes but not through vitronectin-coated membranes. We conclude that: 1) IGF-I stimulates migration of these two cell types through the IGF-I receptor; 2) interaction of vitronectin with the alpha v beta 5 integrin or collagen with the alpha 2 beta 1 integrin is necessary for the complete IGF-I response in MCF-7 cells, and 3) because migration represents an in vitro model for metastatic spread, integrins, extracellular matrix proteins, and IGF-I may play coordinated roles in the metastasis of breast cancer in vivo.
使用改良的博伊登小室检测胰岛素样生长因子I（IGF-I）对两种人乳腺癌细胞系MCF-7和MDA-231迁移的影响。10 ng/ml是刺激迁移的最佳IGF-I浓度。两种细胞类型中，大多数IGF-I刺激的迁移是由于趋化作用。MCF-7细胞在涂有明胶或纤连蛋白的膜上无法迁移，仅在层粘连蛋白上少量迁移。相比之下，当使用玻连蛋白或IV型胶原包被的膜时，MCF-7细胞大量迁移，特别是对IGF-I有反应，而对10%胎牛血清、表皮生长因子、成纤维细胞生长因子或血小板衍生生长因子-BB无反应。IGF-I受体阻断抗体抑制两种细胞类型中IGF-I刺激的迁移。此外，αvβ5整合素（一种玻连蛋白受体）的阻断抗体抑制MCF-7细胞通过玻连蛋白对IGF-I的迁移反应，但不抑制通过IV型胶原的迁移反应。同样，针对α2和β1整合素的特异性阻断抗体显著抑制两种细胞类型通过IV型胶原包被的膜的迁移，但不抑制通过玻连蛋白包被的膜的迁移。我们得出以下结论：1）IGF-I通过IGF-I受体刺激这两种细胞类型的迁移；2）玻连蛋白与αvβ5整合素的相互作用或胶原与α2β1整合素的相互作用对于MCF-7细胞中完整的IGF-I反应是必要的；3）因为迁移代表转移扩散的体外模型，整合素、细胞外基质蛋白和IGF-I可能在体内乳腺癌转移中发挥协同作用。
