Co-localization of cortactin and phosphotyrosine identifies active invadopodia in human breast cancer cells
Co-localization of cortactin and phosphotyrosine identifies active invadopodia in human breast cancer cells
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DOI：
10.1016/j.yexcr.2005.12.012
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发表时间：
2006-05-01
影响因子：
3.7
通讯作者：
Mueller, SC
中科院分区：
文献类型：
--
作者：
Bowden, ET;Onikoyi, E;Mueller, SC
侵袭伪足是具有蛋白酶活性的丝状伪足样突起，参与肿瘤细胞的侵袭。我们证明，coronin和磷酸酪氨酸的共定位确定一个子集coronin点称为“invadopodial复合物”，我们发现是密切相关的细胞外基质在MDA-MB-231乳腺癌细胞中的病灶降解的活性位点的质膜。通过用激酶活化的c-Src（527）或激酶失活的c-Src（295）转染来操纵细胞中的c-Src活性，分别导致这些结构的数量急剧增加或减少，这些结构与活性基质降解位点数量的变化相关。激酶失活的c-Src（295）的过度表达并不能阻止coronin在细胞膜上的定位;然而，共定位的磷酸酪氨酸染色减少。因此，在侵袭伪足复合物中升高的磷酸酪氨酸与侵袭伪足的蛋白水解活性特异性相关。此外，侵袭伪足复合物在空间上、形态上和组成上不同于粘着斑，如通过粘着斑激酶（FAK）的定位所确定的，粘着斑激酶（FAK）不存在于侵袭伪足复合物中。激酶失活的c-Src（295）的表达阻断侵袭伪足活性，但不阻断丝状伪足。阵因此，侵袭伪足，而不是丝状伪足，与基质侵袭高度相关，侵袭伪足活性的位点可以通过侵袭伪足复合物的形成来鉴定。爱思唯尔公司出版
Invadopodia are filopodia-like projections possessing protease activity that participate in tumor cell invasion. We demonstrate that co-localization of cortactin and phosphotyrosine identifies a subset of cortactin puncta termed "invadopodial complexes" that we find to be closely associated with the plasma membrane at active sites of focal degradation of the extracellular matrix in MDA-MB-231 breast cancer cells. Manipulation of c-Src activity in cells by transfection with kinase activated c-Src(527) or kinase inactive c-Src(295) results in a dramatic increase or decrease, respectively, in the number of these structures associated with changes in the number of sites of active matrix degradation. Overexpression of kinase-inactive c-Src(295) does not prevent localization of cortactin at the membrane; however, colocalized phosphotyrosine staining is decreased. Thus, elevated phosphotyrosine at invadopodial complexes is specifically associated with the proteolytic activity of invadopodia. Further, invadopodial complexes are spatially, morphologically and compositionally distinct from focal adhesions as determined by localization of focal adhesion kinase (FAK), which is not present in invadopodial complexes. Expression of kinase-inactive c-Src(295) blocks invadopodia activity, but does not block filopodia. formation. Thus, invadopodia, but not filopodia, are highly correlated with matrix invasion, and sites of invadopodial activity can be identified by the formation of invadopodial complexes. Published by Elsevier Inc.