Heinz Lisa S, Muhs Stefanie, Schiewek Johanna, Grüb Saskia, Nalaskowski Marcus, Lin Yuan-Na, Wikman Harriet, Oliveira-Ferrer Leticia, Lange Tobias, Wellbrock Jasmin, Konietzny Anja, Mikhaylova Marina, Windhorst Sabine
Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Oncotarget. 2017 Nov 1;8(66):110077-110091. doi: 10.18632/oncotarget.22249. eCollection 2017 Dec 15.
High expression of the actin bundling protein Fascin increases the malignancy of tumor cells. Here we show that fascin expression is up-regulated in more malignant sub-cell lines of MDA-MB-231 cells as compared to parental cells. Since also parental MDA-MB-231 cells exhibit high fascin levels, increased fascin expression was termed as "hyperexpression". To examine the effect of fascin hyperexpression, fascin was hyperexpressed in parental MDA-MB-231 cells and metastasis was analyzed in NOD scid gamma (NSG) mice. In addition, the effect of fascin mutants with inactive or constitutively active actin bundling activity was examined. Unexpectedly, we found that hyperexpression of both, wildtype (wt) and mutant fascin strongly increased metastasis , showing that the effect of fascin hyperexpression did not depend on its actin bundling activity. Cellular assays revealed that hyperexpression of wt and mutant fascin increased adhesion of MDA-MB-231 cells while transmigration and proliferation were not affected. Since it has been shown that fascin controls adhesion by directly interacting with MTs), we analyzed if fascin hyperexpression affects MT dynamics. We found that at high concentrations fascin significantly increased MT dynamics in cells and in cell-free approaches. In summary our data show that strong expression of fascin in breast cancer cells increases metastasis independent of its actin bundling activity. Thus, it seems that the mechanism of fascin-stimulated metastasis depends on its concentration.
肌动蛋白成束蛋白Fascin的高表达会增加肿瘤细胞的恶性程度。在此我们表明，与亲代细胞相比，Fascin在MDA-MB-231细胞中更具恶性的亚细胞系中表达上调。由于亲代MDA-MB-231细胞也表现出较高的Fascin水平，因此Fascin表达的增加被称为“过表达”。为了研究Fascin过表达的影响，我们在亲代MDA-MB-231细胞中使Fascin过表达，并在NOD scid gamma（NSG）小鼠中分析转移情况。此外，我们还研究了具有无活性或组成型活性肌动蛋白成束活性的Fascin突变体的作用。出乎意料的是，我们发现野生型（wt）和突变型Fascin的过表达均强烈增加了转移，这表明Fascin过表达的作用并不依赖于其肌动蛋白成束活性。细胞实验表明，wt和突变型Fascin的过表达增加了MDA-MB-231细胞的黏附，而迁移和增殖不受影响。由于已有研究表明Fascin通过直接与微管（MTs）相互作用来控制黏附，我们分析了Fascin过表达是否会影响MT动力学。我们发现，在高浓度下，Fascin显著增加了细胞内和无细胞体系中的MT动力学。总之，我们的数据表明，乳腺癌细胞中Fascin的强表达增加了转移，且不依赖于其肌动蛋白成束活性。因此，Fascin刺激转移的机制似乎取决于其浓度。
