Binding of urokinase-type plasminogen activator to its receptor in MCF-7 cells activates extracellular signal-regulated kinase 1 and 2 which is required for increased cellular motility
Binding of urokinase-type plasminogen activator to its receptor in MCF-7 cells activates extracellular signal-regulated kinase 1 and 2 which is required for increased cellular motility
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DOI：
10.1074/jbc.273.14.8502
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发表时间：
1998-04-03
影响因子：
4.8
通讯作者：
Gonias, SL
中科院分区：
文献类型：
--
作者：
Nguyen, DHD;Hussaini, IM;Gonias, SL
尿激酶型纤溶酶原激活物(UPA)与其受体uPAR的结合调节细胞的黏附、迁移和肿瘤细胞的侵袭，其中一些活性可能反映了uPAR启动信号转导的能力，尽管该受体仅通过糖基磷脂酰肌醇锚点连接到质膜。在本研究中，我们证明了单链uPA激活MCF-7乳腺癌细胞的细胞外信号调节激酶1(ERK1)和ERK2。加入uPA后1min，ERK1和ERK2的磷酸化水平增加，5min后恢复到基础水平，uPA的氨基末端片段(ATF)与uPAR结合但缺乏蛋白酶活性，也激活了ERK1和ERK2。用丝裂原活化蛋白激酶抑制剂PD098059处理MCF-9细胞后，细胞对uPA和ATF的反应被消除，uPA和ATF促进MCF-9细胞在血清包被的Transwell膜上的迁移，迁移增加2.1+/-0.4倍，4.8+/-0.8倍，7.7+/-1.0倍，脉冲作用于uPA 30分钟，然后洗涤去除游离配体。即使允许迁移24小时，PD098059仍表现出运动能力的增加，完全中和了uPA对MCF-7细胞运动的影响，无论uPA是否存在于整个细胞中。这些结果显示了一种新的受体依赖的信号活性，这是uPA刺激的乳腺癌细胞迁移所必需的。
Binding of urokinase-type plasminogen activator (uPA) to its receptor, uPAR, regulates cellular adhesion, migration, and tumor cell invasion, Some of these activities may reflect the ability of uPAR to initiate signal transduction even though this receptor is linked to the plasma membrane only by a glycosylphosphatidylinositol anchor, In this study, we demonstrated that single-chain uPA activates extracellular signal-regulated kinase 1 (ERK1) and ERK2 in MCF-7 breast cancer cells. Phosphorylation of ERK1 and ERK2 was increased 1 min after adding uPA and returned to baseline levels by 5 min, The amino-terminal fragment (ATF) of uPA, which binds to uPAR but lacks proteinase activity, also activated ERK1 and ERK2. Responses to uPA and ATF were eliminated when the cells were pretreated with PD098059, an inhibitor of mitogen-activated protein kinase kinase, uPA and ATF promoted the migration of MCF-9 cells across serum-coated Transwell membranes in vitro, Migration was increased 2.1 +/- 0.4-fold when uPA was added to the top chamber, 4.8 +/- 0.8-fold when uPA was added to the bottom chamber, and 7.7 +/- 1.0-fold when uPA was added to both chambers, MCF-7 cells that were pulse-exposed to uPA for 30 min, and then washed to remove unbound ligand, demonstrated increased motility even though migration was allowed to occur for 24 h, PD098059 completely neutralized the effects of uPA on MCF-7 cellular-motility, irrespective of whether the uPA was present for the entire. motility assay or administered by pulse-exposure, These results demonstrate a novel, receptor-dependent signaling activity which is required for uPA-stimulated breast cancer cell migration.