Unité Mixte de Recherche 168, and Unité Mixte de Recherche 144, Institut Curie, Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 26 rue d'Ulm, 75248 Paris cedex 05, France.
Proc Natl Acad Sci U S A. 2011 May 3;108(18):7315-20. doi: 10.1073/pnas.1018057108. Epub 2011 Apr 19.
We study the spreading of spheroidal aggregates of cells, expressing a tunable level of E-cadherin molecules, on glass substrates decorated with mixed fibronectin and polyethylene glycol. We observe the contact area by optical interferometry and the profile by side-view microscopy. We find a universal law of aggregate spreading at short times, which we interpret through an analogy with the spreading of viscoelastic droplets. At long times, we observe either partial wetting or complete wetting, with a precursor film of cells spreading around the aggregate with two possible states. In strongly cohesive aggregates this film is a cellular monolayer in the liquid state, whereas in weakly cohesive aggregates, cells escape from the aggregate, forming a 2D gas. The escape of isolated cells is a physical mechanism that appears also to be present in the progression of a noninvasive tumor into a metastatic malignant carcinoma, known as the epithelial-mesenchymal transition.
我们研究了在玻璃基板上表达可调节水平的 E-钙黏蛋白分子的球形细胞聚集体的扩散，该玻璃基板上涂有混合的纤维连接蛋白和聚乙二醇。我们通过光学干涉测量法观察接触面积，并通过侧视显微镜观察轮廓。我们发现短时间内聚集体扩散具有普适规律，我们通过与粘弹性液滴扩散的类比来解释这一规律。在长时间内，我们观察到部分润湿或完全润湿，细胞的预成膜在聚集体周围以两种可能的状态扩散。在强内聚的聚集体中，该膜处于液态的单层细胞状态，而在弱内聚的聚集体中，细胞从聚集体中逸出，形成二维气体。孤立细胞的逸出是一种物理机制，似乎也存在于非侵袭性肿瘤向转移性恶性癌（上皮-间充质转化）的进展过程中。
