Institut National de la Santé et de la Recherche Médicale, U1053, F-33076 Bordeaux, France Université de Bordeaux, F-33076 Bordeaux, France.
National Heart and Lung Institute, Imperial College London, London SW7 2AZ, England, UK.
J Cell Biol. 2014 Nov 24;207(4):517-33. doi: 10.1083/jcb.201404079.
Accumulation of type I collagen fibrils in tumors is associated with an increased risk of metastasis. Invadosomes are F-actin structures able to degrade the extracellular matrix. We previously found that collagen I fibrils induced the formation of peculiar linear invadosomes in an unexpected integrin-independent manner. Here, we show that Discoidin Domain Receptor 1 (DDR1), a collagen receptor overexpressed in cancer, colocalizes with linear invadosomes in tumor cells and is required for their formation and matrix degradation ability. Unexpectedly, DDR1 kinase activity is not required for invadosome formation or activity, nor is Src tyrosine kinase. We show that the RhoGTPase Cdc42 is activated on collagen in a DDR1-dependent manner. Cdc42 and its specific guanine nucleotide-exchange factor (GEF), Tuba, localize to linear invadosomes, and both are required for linear invadosome formation. Finally, DDR1 depletion blocked cell invasion in a collagen gel. Altogether, our data uncover an important role for DDR1, acting through Tuba and Cdc42, in proteolysis-based cell invasion in a collagen-rich environment.
肿瘤中 I 型胶原纤维的积累与转移风险的增加有关。侵入小体是能够降解细胞外基质的 F-肌动蛋白结构。我们之前发现胶原 I 纤维以一种意想不到的、不依赖整合素的方式诱导形成特殊的线性侵入小体。在这里,我们表明在癌症中过度表达的胶原受体 Discoidin Domain Receptor 1(DDR1)与肿瘤细胞中的线性侵入小体共定位,并需要其形成和基质降解能力。出乎意料的是,侵入小体的形成或活性并不需要 DDR1 激酶活性,也不需要Src 酪氨酸激酶。我们表明,Cdc42 在胶原上以 DDR1 依赖性的方式被激活。Cdc42 及其特定的鸟嘌呤核苷酸交换因子(GEF)Tuba 定位于线性侵入小体,两者都需要线性侵入小体的形成。最后,DDR1 的耗竭阻止了细胞在胶原凝胶中的侵袭。总之,我们的数据揭示了 DDR1 通过 Tuba 和 Cdc42 在富含胶原的环境中基于蛋白水解的细胞侵袭中的重要作用。