Veß Astrid, Blache Ulrich, Leitner Laura, Kurz Angela R M, Ehrenpfordt Anja, Sixt Michael, Posern Guido
Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, 06114 Halle (Saale), Germany.
Max Planck Institute of Biochemistry, 82152 Martinsried near Munich, Germany.
J Cell Sci. 2017 Jul 1;130(13):2172-2184. doi: 10.1242/jcs.200899. Epub 2017 May 17.
A change regarding the extent of adhesion - hereafter referred to as adhesion plasticity - between adhesive and less-adhesive states of mammalian cells is important for their behavior. To investigate adhesion plasticity, we have selected a stable isogenic subpopulation of human MDA-MB-468 breast carcinoma cells growing in suspension. These suspension cells are unable to re-adhere to various matrices or to contract three-dimensional collagen lattices. By using transcriptome analysis, we identified the focal adhesion protein tensin3 (Tns3) as a determinant of adhesion plasticity. Tns3 is strongly reduced at mRNA and protein levels in suspension cells. Furthermore, by transiently challenging breast cancer cells to grow under non-adherent conditions markedly reduces Tns3 protein expression, which is regained upon re-adhesion. Stable knockdown of Tns3 in parental MDA-MB-468 cells results in defective adhesion, spreading and migration. Tns3-knockdown cells display impaired structure and dynamics of focal adhesion complexes as determined by immunostaining. Restoration of Tns3 protein expression in suspension cells partially rescues adhesion and focal contact composition. Our work identifies Tns3 as a crucial focal adhesion component regulated by, and functionally contributing to, the switch between adhesive and non-adhesive states in MDA-MB-468 cancer cells.
哺乳动物细胞在粘附状态和低粘附状态之间粘附程度的变化——以下简称粘附可塑性——对其行为至关重要。为了研究粘附可塑性，我们选择了在悬浮培养中生长的人MDA-MB-468乳腺癌细胞的一个稳定的同基因亚群。这些悬浮细胞无法重新粘附到各种基质上，也无法收缩三维胶原晶格。通过转录组分析，我们确定粘着斑蛋白张力蛋白3（Tns3）是粘附可塑性的一个决定因素。在悬浮细胞中，Tns3的mRNA和蛋白质水平显著降低。此外，通过短暂地使乳腺癌细胞在非粘附条件下生长，可显著降低Tns3蛋白表达，而重新粘附后该表达得以恢复。在亲本MDA-MB-468细胞中稳定敲低Tns3会导致粘附、铺展和迁移缺陷。通过免疫染色确定，Tns3敲低的细胞显示粘着斑复合物的结构和动力学受损。悬浮细胞中Tns3蛋白表达的恢复部分挽救了粘附和粘着斑组成。我们的研究确定Tns3是一个关键的粘着斑成分，受MDA-MB-468癌细胞粘附和非粘附状态之间转换的调控，并在功能上对其有贡献。
