氟维司群对乳腺癌细胞迁移及局部黏着斑激酶的影响

Effects of fulvestrant on the migration and focal adhesion kinase in breast cancer cells

背景与目的：雌激素（estrogen，E2）受体（estrogen receptor，ER）拮抗剂氟维司群（fulvestrant或ICI182780，ICI）是治疗绝经后妇女乳腺癌的新型药物，而局部粘着斑激酶（focal adhesion kinase，FAK）与乳腺癌转移密切相关。本研究通过观察E2和ICI单独或联合作用对ER阳性乳腺癌细胞迁移及FAK表达的影响，探讨ICI对肿瘤细胞迁移的作用及其与FAK的关系。方法：采用E邸日性MCF-7乳腺癌细胞为研究模型，以E2（包括酒精，EtOH）和ICI单独或联合刺激细胞，采用蛋白质印迹法（Westernblot）检测蛋白表达及相对分子质量变化，伤口愈合实验检测细胞迁移变化。结果：E2（10nmol／L）和EtOH（0．3％）组均可明显刺激MCF-7细胞迁移（与DMSO组比较，分别增加51．5％和53．6％，P〈0．01），但E2＋EtOH组对细胞迁移并无协同作用（与DMSO组比较，增加45．0％）。以ICI（10μmol／L）预处理细胞后再给予E2处理，与对照组比较，细胞迁移增加了（38．9±4．9）％（P〈0．01），与E2组比较减少了（8．32±3．21）％（P〈0．05）；ICI单独作用可明显促进细胞迁移（与DMSO组比较，增加19．1％，P〈0．01）。对照组细胞FAK主要为125×10^3和110×10^3两种形式，E2刺激可诱导FAK（125×10^3）呈现时间依赖性蛋白剪切，生成相对分子质量为35×10^3-70×10^3的小分子片段，而ICI预处理可有效阻断E2诱导的p125FAK蛋白剪切反应。结论：ICI单独作用可明显刺激MCF-7乳腺癌细胞迁移，但ICI对E2诱导的MCF-7细胞迁移具有抑制作用，该抑制效应可能与ICI阻断FAK蛋白剪切有关。

Background and purpose： Fulvestrant （ICI182780, ICI） is a novel anti-estrogan drug for treatment of metastatic breast cancer, and focal adhesion kinase （FAK） is strongly involved in metastasis of breast cancer. This study was performed to investigate the impact of ICI on the estrogen （E2）-induced cell migration and its association with expression of FAK in estrogen receptor （ER）-positive breast cancer cells. Methods： ER- positive MCF-7 breast cancer cells were employed as a model system. E2, ethanol （EtOH） or ICI was used alone or in combination to treat model cells. Western blot was applied to analyze protein expression and wound healing assay to assess cell migration. Results： Both E2 and EtOH stimulated significant migration of MCF-7 cells, but no cooperative effect was observed. Importantly, ICI had significant inhibitory effect on E2-induced migration, while ICI, when used alone, also enhanced cell migration. When cells were not insulted, FAK was primarily expressed in the forms of 125 × 10^3 and 110× 10^3, and E2 treatment triggered cleavage of FAK （p 125） into low molecular isoforms. E2 treatment produced time-dependent proteolysis of FAK and this effect was blocked by pretreatment with ICI. Conclusion： ICI stimulates cell migration in MCF-7 cells when used alone, while it inhibits E2-enhanced migration possibly by blocking proteolysis of FAK.