Marrero-Diaz Raquel, Bravo-Cordero Jose J, Megías Diego, García Maria A, Bartolomé Ruben A, Teixido Joaquin, Montoya María C
Confocal Microscopy and Cytometry Unit, Biotechnology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid, Spain.
Cell Motil Cytoskeleton. 2009 Jan;66(1):48-61. doi: 10.1002/cm.20325.
The adhesion molecule CD44 and the membrane-type matrix metalloproteinase MT1-MMP act coordinately in tumor cells to promote cell invasion through a yet unclear mechanism. We are interested in studying the interplay between CD44 and MT1-MMP in carcinoma cells embedded in HA containing three-dimensional collagen I matrices (3D HA-Col I) by time-lapse confocal microscopy imaging. Here we report the in vivo interaction between CD44 and MT1-MMP, revealed by fluorescence resonance energy transfer (FRET) microscopy. MT1-MMP interacts with CD44 preferentially at the trailing edge of the invading tumor cells during rear retraction and on membrane fragments released during the invasion process. A fluorescent biosensor designed to monitor the proteolytic processing of CD44 by live cell imaging demonstrates that cleavage of the CD44 extracellular domain is enriched in the retracting rear ends of invasive tumor cells. Invasion assays showed that MT1-MMP mediates CD44-dependent tumor-cell invasion, whereas CD44 is not essential for MT1-MMP-mediated invasion of 3D HA-Col I matrices. Together, our results support a role for MT1-MMP in cell retraction during CD44-mediated cell invasion.
黏附分子CD44与膜型基质金属蛋白酶MT1-MMP在肿瘤细胞中协同作用，通过一种尚不清楚的机制促进细胞侵袭。我们有兴趣通过延时共聚焦显微镜成像研究嵌入含透明质酸的三维I型胶原基质（3D HA-Col I）中的癌细胞中CD44与MT1-MMP之间的相互作用。在此，我们报告通过荧光共振能量转移（FRET）显微镜揭示的CD44与MT1-MMP在体内的相互作用。在肿瘤细胞回缩期间，MT1-MMP优先在侵袭性肿瘤细胞的后缘以及侵袭过程中释放的膜碎片上与CD44相互作用。一种设计用于通过活细胞成像监测CD44蛋白水解过程的荧光生物传感器表明，CD44胞外域的裂解在侵袭性肿瘤细胞回缩的后端更为富集。侵袭实验表明，MT1-MMP介导依赖CD44的肿瘤细胞侵袭，而CD44对于MT1-MMP介导的3D HA-Col I基质侵袭并非必需。总之，我们的结果支持MT1-MMP在CD44介导的细胞侵袭过程中的细胞回缩中发挥作用。
