Turner David P, Findlay Victoria J, Kirven A Darby, Moussa Omar, Watson Dennis K
Department of Pathology and Laboratory Medicine, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA.
Mol Biol Cell. 2008 Sep;19(9):3745-57. doi: 10.1091/mbc.e08-02-0154. Epub 2008 Jun 25.
Prostate derived ETS factor (PDEF) is an ETS (epithelial-specific E26 transforming sequence) family member that has been identified as a potential tumor suppressor. In multiple invasive breast cancer cells, PDEF expression inhibits cell migration by preventing the acquisition of directional morphological polarity conferred by changes in cytoskeleton organization. In this study, microarray analysis was used to identify >200 human genes that displayed a common differential expression pattern in three invasive breast cancer cell lines after expression of exogenous PDEF protein. Gene ontology associations and data mining analysis identified focal adhesion, adherens junctions, cell adhesion, and actin cytoskeleton regulation as cell migration-associated interaction pathways significantly impacted by PDEF expression. Validation experiments confirmed the differential expression of four cytoskeleton-associated genes with known functional associations with these pathways: uPA, uPAR, LASP1, and VASP. Significantly, chromatin immunoprecipitation studies identified PDEF as a direct negative regulator of the metastasis-associated gene uPA and phenotypic rescue experiments demonstrate that exogenous urokinase plasminogen activator (uPA) expression can restore the migratory ability of invasive breast cancer cells expressing PDEF. Furthermore, immunofluorescence studies identify the subcellular relocalization of urokinase plasminogen activator receptor (uPAR), LIM and SH3 protein (LASP1), and vasodilator-stimulated protein (VASP) as a possible mechanism accounting for the loss of morphological polarity observed upon PDEF expression.
前列腺源性ETS因子（PDEF）是ETS（上皮特异性E26转化序列）家族成员，已被确定为一种潜在的肿瘤抑制因子。在多种侵袭性乳腺癌细胞中，PDEF的表达通过阻止细胞骨架组织变化赋予的定向形态极性的获得来抑制细胞迁移。在本研究中，利用微阵列分析鉴定了200多个在表达外源性PDEF蛋白后的三种侵袭性乳腺癌细胞系中呈现共同差异表达模式的人类基因。基因本体关联和数据挖掘分析确定粘着斑、紧密连接、细胞粘附和肌动蛋白细胞骨架调节为受PDEF表达显著影响的与细胞迁移相关的相互作用途径。验证实验证实了四个与这些途径具有已知功能关联的细胞骨架相关基因的差异表达：尿激酶型纤溶酶原激活剂（uPA）、尿激酶型纤溶酶原激活剂受体（uPAR）、LIM和SH3结构域蛋白1（LASP1）以及血管舒张刺激蛋白（VASP）。重要的是，染色质免疫沉淀研究确定PDEF为转移相关基因uPA的直接负调节因子，表型拯救实验表明外源性尿激酶型纤溶酶原激活剂（uPA）的表达可恢复表达PDEF的侵袭性乳腺癌细胞的迁移能力。此外，免疫荧光研究确定尿激酶型纤溶酶原激活剂受体（uPAR）、LIM和SH3蛋白（LASP1）以及血管舒张刺激蛋白（VASP）的亚细胞重新定位是解释PDEF表达时观察到的形态极性丧失的一种可能机制。
