Aiming for invadopodia: organizing polarized delivery at sites of invasion.
Recent years have witnessed growing interest in the biology of invadopodia, proteolytically active protrusions formed by invasive tumor cells when cultured on an extracellular matrix (ECM). Although substantial progress has been made towards defining their basic elements and features, the need remains to understand how these components are recruited and, ultimately, how ECM degradation is so precisely localized. According to recent evidence, invadopodia are raft-like membrane domains where cholesterol levels are tightly regulated, and active transport of protease-delivering carriers is required for their function. On this basis we hypothesize that the correct delivery of cargo to invadopodia is ensured by a polarized, cholesterol-dependent trafficking mechanism, similar to that of the apical domain of epithelial cells.
Caldieri
Giusi
G
Tumor Cell Invasion Laboratory, Consorzio Mario Negri Sud, S. Maria Imbaro (Chieti), 66030 Italy.
Buccione
Roberto
R
D000818:Animals; D002465:Cell Movement / Q000502:physiology; D016764:Cell Polarity / Q000502:physiology*; D022081:Cell Surface Extensions / Q000378:metabolism* / Q000648:ultrastructure; D002784:Cholesterol / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology; D005109:Extracellular Matrix / Q000378:metabolism*; D006801:Humans; D021962:Membrane Microdomains / Q000378:metabolism / Q000648:ultrastructure; D009361:Neoplasm Invasiveness / Q000503:physiopathology*; D014407:Tumor Cells, Cultured
D002784:Cholesterol