Towards the mechanism of formation and function of tunneling nanotubes

Recently we have discovered that mammalian cells are connected by thin membrane tubes . These tubes with a diameter of 50 to 200 nm are referred to as tunneling nanotubes (TNTs). They are a continuation of the cell membrane and are formed de novo when fil opodia-like projections of one cell make contact with a neighboring cell and can lead to complex cellular networks. TNTs facilitate the selective, unidirectional transfer of organelles, cytoplasmic components like calcium and cell surface molecules. The d ata suggest a new biological principle of cell-to-cell communication, which may have important implications in various fields of biomedical and clinical research. We here propose to use micro-and nanopatterned surfaces as a central tool to study the mecha nism of TNT-formation. Furthermore, we aim at establishing a 3D cell culture system to study TNT formation and function between physiological meaningful cell types. Given the emerging view that TNTs seem to play an important role in various pathologies i ncluding cancer and immune diseases, the elucidation of the molecular machinery underlying the TNT-dependent cell-to-cell communicaton could provide molecular strategies for designing diagnostic and therapeutical tools. As a long-term perspective, they ma y also provide the necessary platform for the design of a nanomachine suited for the transport of cargo through a tissue of interest. In this respect tumor tissue will be one of the most relevant targets.