Regulation of invadosomes by microtubules: Not only a matter of railways.

Invadosomes, which encompass podosomes and invadopodia, are actin rich adhesive and protrusive structures facilitating invasion and migration in various cell types. Podosomes are mostly found in normal cells, while invadopodia are hallmarks of invasive transformed cells. Despite evident structural differences, both structures mostly rely on the same pathways for their formation and their activity. While the role of actin cytoskeleton is undeniable, the involvement of microtubules (MTs) in invadosome formation/activity has recently been demonstrated but also somehow underestimated. MTs are components of the eukaryotic cytoskeleton well known for their essential roles for cell division, the maintenance of cell shape, intracellular transport and cell motility. Until now, MTs were mostly seen as railways for the delivery of various cargos required for invadosome functions but recent data suggest a more complex role. In this review, we address the specific functions of MTs on invadosome dynamics, activity, maturation and organization in light with recent data, which extended far beyond simple track delivery. Indeed, MT dynamic instability, which in turn modulates Rho GTPase signalling and likely MT post-translational modifications are playing major roles in invadosome functions.