Rab'ing tumor cell migration and invasion: focal adhesion disassembly driven by Rab5.

The small GTPase Rab5 has been extensively studied in the context of endocytic trafficking because it is critical in the regulation of early endosome dynamics. In addition to this canonical role, evidence obtained in recent years implicates Rab5 in the regulation of cell migration. This novel role of Rab5 is based not only on an indirect relationship between cell migration and endosomal trafficking as separate processes, but also on the direct regulation of signaling proteins implicated in cell migration. However, the precise mechanisms underlying this connection have remained elusive. Recent studies have shown that the activation of Rab5 is a critical event for maintaining the dynamics of focal adhesions, which is fundamental in regulating not only cell migration but also tumor cell invasion.