【摘要】 目的探讨经雌激素(E2)转化的MCF-10A乳腺上皮细胞对E2刺激的敏感性及细胞内钙蛋白酶(CANP)在E2效应中的介导作用,以深入了解E2的信号传导机制。方法以E2转化的MCF-10A乳腺上皮细胞为研究模型、用E2(50 nmol/L)刺激细胞,以蛋白印迹法观察蛋白分子质量变化,以CANP特异性底物局部黏着激酶(FAK)蛋白剪切作为CANP激活的指标,伤口愈合实验观察细胞迁移变化,CANP抑制剂预处理观察CANP在E2效应中的作用。结果转化细胞CANP活性明显高于非转化细胞,表现为前者出现FAK明显蛋白剪切,而后者FAK主要为野生型(125 ku),同时转化细胞迁移明显增强(P<0.01)。E2(10 nmol/L)刺激转化细胞可进一步促进FAK蛋白剪切和细胞迁移(P<0.01),而非转化细胞对E2刺激不敏感。CANP抑制剂-1(ALLN)可有效阻断E2刺激转化细胞FAK蛋白剪切及细胞迁移(P<0.01)。结论转化细胞对E2刺激的敏感性增加,其机制可能与胞内CANP活性增强有关,提示在转化细胞存在活跃的E2-CANP-FAK信号活动。更多还原

【Abstract】 Objective To investigate the sensitirity of 17βestradiol(E2)-transformed MCF-10A mammary epithelial cells to E2 stimulation and the role of calpain(CANP) in the E2-induced effect.Methods E2-transformed MCF-10A mammary epithelial cells were prepared and used as a model system.Western blotting was employed to observe proteolysis of focal adhesion kinase(FAK)as a marker of calpain activity,wound healing assay was performed to investigate cell migration.Calpain inhibitor was used to find role of calpain in the E2-induced effect.Results In non-transformed MCF-10A cells,focal adhesion kinase(FAK) was primarily expressed in the form of wild type,while in E2(50 nmol/L)-transformed cells FAK was significantly proteolyzed,indicating increased activity of calpain.Furthermore,transformed cells showed increased migration as compared with control(P<0.01).Treatment of transformed cells with E2(10 nmol/L) triggered further truncation of FAK and enhancement of migration(P<0.01),while non-transformed cells were resistant to E2 stimulation.Additionally,pre-treatment of transformed cells with calpain inhibitor-1(ALLN,10 μmol/L) abrogated E2-enhanced FAK processing and migration(P<0.01).Conclusions Transformed MCF10-A mammary epithelial cells displays increased responsiveness to E2 stimulation,and this effect may be mediated through activation of calpain,indicating an active E2-CANP-FAK signaling in the transformed cells.更多还原