Department of Biochemistry, Faculty of Medicine and Health Sciences, Ghent University, Campus Rommelaere, Albert Baertsoenkaai 3, B-9000, Ghent, Belgium.
Biomed Pharmacother. 2018 Jun;102:230-241. doi: 10.1016/j.biopha.2018.03.064. Epub 2018 Mar 22.
Cortactin is a multidomain actin binding protein that activates Arp2/3 mediated branched actin polymerization. This is essential for the formation of protrusive structures during cancer cell invasion. Invadopodia are cancer cell-specific membrane protrusions, specialized at extracellular matrix degradation and essential for invasion and tumor metastasis. Given the unequivocal role of cortactin at every stage of invadopodium formation, it is considered an invadopodium marker and potential drug target. We used cortactin nanobodies to examine the role of cortactin domain-specific function at endogenous protein level. Two cortactin nanobodies target the central region of cortactin with high specificity. One nanobody interacts with the actin binding repeats whereas the other targets the proline rich region and was found to reduce EGF-induced cortactin phosphorylation. After intracellular expression as an intrabody, they are both capable of tracing their target in the complex environment of the cytoplasm, and disturb cortactin functions during invadopodia formation and extracellular matrix degradation. These data illustrate the use of nanobodies as a research tool to dissect the role of cortactin in cancer cell motility. This information can contribute to the development of novel therapeutics for tumor cell migration and metastasis.
桩蛋白是一种多功能肌动蛋白结合蛋白，可激活 Arp2/3 介导的分支肌动蛋白聚合。这对于癌细胞侵袭过程中突起结构的形成是必不可少的。侵袭伪足是癌细胞特异性的膜突起，专门参与细胞外基质的降解，对于侵袭和肿瘤转移至关重要。鉴于桩蛋白在侵袭伪足形成的每个阶段都起着明确的作用，它被认为是侵袭伪足的标志物和潜在的药物靶点。我们使用桩蛋白纳米体在内源性蛋白水平上研究了桩蛋白特定结构域功能的作用。两种桩蛋白纳米体特异性地靶向桩蛋白的中心区域。一种纳米体与肌动蛋白结合重复相互作用，而另一种则靶向富含脯氨酸的区域，并发现其可减少 EGF 诱导的桩蛋白磷酸化。作为内体在细胞内表达后，它们都能够在细胞质的复杂环境中追踪其靶标，并在侵袭伪足形成和细胞外基质降解过程中干扰桩蛋白的功能。这些数据说明了纳米体作为一种研究工具在解析桩蛋白在癌细胞运动中的作用。这些信息可以为肿瘤细胞迁移和转移的新型治疗方法的开发做出贡献。
